Journal articles on the topic 'Tai-chi (the great limit)'

The coastal zone worldwide is not well served by management policies that fail to deal effectively with land-sourced contaminants from streams, rivers and urban runoff. We discuss this using examples from New Zealand, where there is a wide recognition of such problems but little effective policy that specifically accounts for the interconnectedness of the land-to-freshwater-to-sea domain. Increasing land-use intensification, mostly in arable pasture, has greatly increased the nutrient load to the coast and has contributed to the already high sediment loading of coastal waters. We argue that renewed effort is needed for a more holistic approach to management, encapsulated in the New Zealand Maori concept of ki uta ki tai – an appreciation of mountains-to-sea connections. Limit-setting, especially of nitrogen from terrestrial sources, seems to a main way forward for reducing loads and halting cumulative effects. However, this must account for current impacts and also the ‘load to come’ because of time lags associated with accumulated groundwater nutrients and cumulative impacts in receiving waters. Despite many approaches being tried, there are increasing impacts of catchment activities on coasts worldwide. The need is therefore great for new approaches, renewed effort, and for a very long-term perspective to ensure effective and enduring solutions.

The study aims to identify factors influencing the parents’ decision in Ho Chi Minh City to send their children to study abroad. The study used the exploratory factor analysis method to examine and estimate regression coefficients on sample 243 observations from parents whose children study abroad. Research has identified 6 factors affecting the decision to send a child to study abroad. The paper shows that the parents’ decisions to let their children study abroad are not only based on the parents’ desire but also on the students’ desire. In addition, factors such as the family’s financial capacity, training programs, career prospects, and self-reliance also affect the parents’ decisions to send their children to study abroad. Interestingly, the study found that factors of self-reliance have negative impacts on parents’ decisions to send their children to study abroad. When they realized that their child may have good self-reliance, great success would be obtained regardless of study location. As a result, motivation for the overseas study was no longer found by them. Since then, domestic training programs need to increase opportunities to practice English, the opportunity to practice independence and flexibility in training programs will limit your children to study abroad.

AbstractThe position of the jugular bulb (JB) is of great clinical significance to the otologist. A high and laterally situated jugular bulb may pose difficulties when dealing with the middle ear while a high and medially sited jugular bulb can create problems in neuro-otological surgery. This paper aims to study possible racial differences in the position of the jugular bulb.Fine-cut computed tomogram (CT) scans of temporal bones (in the axial plane) of 34 Caucasians and 34 Chinese were studied. The position of the jugular bulb was determined with reference to the midpoint of the lumen at the inferior limit of the cochlea (mpC).Of the 60 Caucasian and 58 Chinese temporal bones with identifiable jugular bulbs, 33 jugular bulbs of the Caucasian (55 percent) and 34 jugular bulbs of the Chinese (58.6 percent) were at the same height or higher than the mpC (p = 0.2; chi-squared test). The midpoint of the jugular bulb was 8.67 ± 1.73 and 8.61 ± 2.49 mm posterior to the mpC for the Caucasian and Chinese respectively (p = 0.2; t-test). However, the midpoint of the jugular bulb of eight Caucasian (24.2 percent) and 22 Chinese (64.7 percent) were medial to the mpC (p<0.001; chi-squared test).Race does not influence the height of the jugular bulb nor its position in the sagittal plane but can influence whether a high jugular bulb is medially or laterally situated.

This study assessed an alternative concept for co-treatment of sewage and organic kitchen waste in Vietnam. The goal was to apply direct membrane filtration for sewage treatment to generate a permeate that is suitable for discharge. The obtained chemical oxygen demand (COD) concentrations in the permeate of ultrafiltration tests were indeed under the limit value (50 mg/L) of the local municipal discharge standards. The COD of the concentrate was 5.4 times higher than that of the initial feed. These concentrated organics were then co-digested with organic kitchen wastes at an organic loading rate of 2.0 kg VS/m3.d. The volumetric biogas production of the digester was 1.94 ± 0.34 m3/m3.d. The recovered carbon, in terms of methane gas, accounted for 50% of the total carbon input of the integrated system. Consequently, an electrical production of 64 Wh/capita/d can be obtained when applying the proposed technology with the current wastes generated in Ho Chi Minh City. Thus, it is an approach with great potential in terms of energy recovery and waste treatment.

The prevalence of Chronic Obstructive Pulmonary Disease (COPD) continues to increase in the world and predicted in 2030 to rank third in the world. COPD causes people to have difficulty breathing, limit mobility and lifestyle, and can cause more serious complications and lead to a decrease in quality of life. One of the nonpharmacological treatments that can be done is Tai chi a traditional Chinese mind-body exercise. Objective: This literature study aims to describe benefits of Tai chi in improving the quality of life of patients with COPD. Literature review was conducted from various sources such as CINAHL, MEDLINE, science Direct and proquest. Tai chi was a meditative martial art consisting of three basic concepts namely physical exercise, breathing techniques, and full awareness. Tai chi movements that were practiced vary, such as 24 movements which were or 6 movements that have been modified and simplified. Some of the benefits of doing Tai chi include increased muscle strength, reduced tightness, improved pulmonary function, increased 6-minute walk distance (6MWD) and increased St. George’s Respiratory Questionnaire (SGRQ) scores. Tai chi can be used as a complementary therapy in COPD patients according to their preferences and values. In addition this exercise can be recommended in patients with other chronic diseases. Keywords: Tai chi; COPD; complementary therapy ABSTRAK Prevalensi Penyakit Paru Obstruksi Kronis (PPOK) terus meningkat di dunia dan diprediksikan pada tahun 2030 akan menempati urutan ketiga di dunia. PPOK menyebabkan penderita sulit bernafas, membatasi mobilitas dan gaya hidup, serta dapat menyebabkan komplikasi yang lebih serius dan mengarah kepada penurunan kualitas hidup. Salah satu penatalaksanaan non farmakologis yang dapat dilakukan ialah Tai chi, latihan mind-body tradisional Tiongkok. Studi literatur ini bertujuan untuk menggambarkan manfaat Tai chi pada peningkatan kualitas hidup pada pasien PPOK. Penulusuran literature dilakukan dari berbagai sumber seperti CINAHL, MEDLINE, Science Direct dan proquest. Tai chi merupakan seni bela diri yang bersifat meditasi yang terdiri dari tiga konsep dasar yaitu latihan fisik, teknik pernapasan, dan kesadaran penuh. Gerakan Tai chi yang dipraktikkan bervariasi, seperti 24 gerakan Yang atau 6 gerakan yang telah dimodifikasi dan disederhanakan. Beberapa manfaat melakukan Tai chi seperti peningkatan kekuatan otot, mengurangi sesak, meningkatkan fungsi paru, meningkatkan 6-minute walk distance (6MWD) dan peningkatan skor St. George’s Respiratory Questionnaire (SGRQ). Tai chi dapat dijadikan terapi pelengkap pada pasien PPOK sesuai dengan preference dan nilai yang dimiliki individu. Latihan ini dapat direkomendasikan pada pasien penyakit kronis lainnya. Kata kunci: Tai chi; PPOK; terapi komplementer

The sense of food insecurity in a group of elderly people may be determined by the perception of distance to food outlets. The aim of the study was to assess the relationship between the perception of food insecurity by the elderly and their perception of the distance between the places of residence and food purchase. A cross-sectional quantitative survey was carried out in 2019–2020 amongst 762 Polish elderly living in Świętokrzyskie and Śląskie Voivodeship. The assessment of the relationships between the perceived food insecurity due to living too far away from the grocery shops and socio-demographic features was performed using multiple correspondence analysis (MCA), chi-square tests, and Phi and Cramér’s V coefficients. Too great a distance to the place of food purchase was the cause of a lack of a sense of food security in 20.5% of the study sample, especially in men, people aged 75 and more, people living in a rural environment and people living alone. People reporting a lack of food due to the distance to the place of purchase showed socio-demographic characteristics similar to those of people declaring a lack of a sense of food security. Reduced food consumption due to the distance from the place of sale, including of fish (24.8%), some fruits (18.9%) and vegetables (15.4%) and beef (17.3%), may contribute to the deterioration of the diet and, as a result, health conditions. Including access to places of the sale of food in food policy as a factor contributing to ensuring the food security of older people can help to maintain a better quality of life and avoid exclusion. Especially in a situation of limited independence, food insecurity in elders due to causes other than financial limitations should be a focus of food policy.

Background. Tai Chi (TC) is known to enhance balance control and walking function in stroke survivors. However, motor disorders in stroke patients may limit the implementation of TC exercise and increase the risk of falling. The body weight support (BWS) device can provide protection during the early rehabilitation of stroke survivors using an overhead suspension system. Theoretically, combining TC with BWS may be an effective intervention for stroke survivors. This study aimed to examine the effects of body weight support-Tai Chi training on balance control and walking function in stroke survivors with hemiplegia. Methods. Seventy-one stroke survivors with hemiplegia aged 30–75 years were randomly allocated to the control group (N = 35) or the BWS-TC group (N = 36). During BWS-TC training, the subjects performed 7 Tai Chi footwork forms, and gradual easy-to-difficult progression (from 40% to 0% body weight) was followed. The subjects participated in 40 min rehabilitation sessions three times per week for 12 weeks. The primary outcome was dynamic balance in the limits-of-stability test. The secondary outcomes, which reflect improvements walking function, included spatiotemporal parameters, the joint range of motion in the affected limb during the swing phase, the Berg Balance Scale score, and the Fugl-Meyer Assessment score. Evaluations were performed at baseline and 12 weeks and compared between groups. Results. After training, significant between-group differences were observed in the scores for overall, forward, left, right, forward-left, and forward-right directional control in the limits-of-stability test ( P < 0.05 ). Furthermore, the scores for gait cycle time, step length, step velocity, and range of motion of the joints were better in the BWS-TC group than in the control group ( P < 0.05 ). Conclusions. The 12-week BWS-TC training may enhance dynamic balance and walking function in stroke survivors with hemiplegia.

IntroductionAcute ischaemic stroke (AIS) is not only seriously damaging to the physical and mental health of patients, but also has become a major social public health problem. Effective dyskinesia rehabilitation treatment in convalescence is of great significance for AIS patients’ prognosis and quality of life. Tai Chi (TC) shows great potential in improving motor function. This trial aims to evaluate the clinical efficacy of modified TC postural training (TPT), and to explore the related central-peripheral neurotransmitter mechanisms.Methods/designThe proposed study will be a multicentre randomised controlled trial. The trial will randomise 120 eligible AIS patients in a 1:1 ratio to receive TPT or Bobath rehabilitation training. Each training session will last 40 min and will be implemented once a day and five times per week (from Monday to Friday) in a duration of 4 weeks. After finishing the 4-week treatment, another 3-month follow-up period will be seen. Root mean square generated from the surface electromyogram (sEMG) will be the primary outcome. Other sEMG time-domain parameters and frequency-domain parameters and clinical scales assessment will be the secondary outcomes. Peripheral blood samples will be collected at baseline and at the end of 4-week treatment, which will be used to explore the related therapeutic mechanisms. Intention-to-treat analysis and per-protocol analysis will both be implemented in this trial.Ethics and disseminationThe study has been approved by Ethics Committee of Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, being granted approval numbers DZMEC-KY-2020–22. The research results will be disseminated through (open access) peer-reviewed publications and presentations at conferences.Trial registration numberChiCTR2000032999.

Tai Chi Chuan (TCC) as a typical mind-body practice has been investigated for its preventive role on negative emotions and has demonstrated its efficacy in healthy populations. However, the results are not consistent. We performed a meta-analysis and systematically evaluated the effect of TCC on selected negative emotions (i.e., anxiety and depression). Fourteen experimental studies from three English-and two Chinese-language databases were evaluated. The results showed that the positive effects of TCC on negative emotions were moderately to largely significant. In addition, although TCC significantly improved negative emotions in both the young adults and the older adults, old adults benefited more from TCC than young adults. These findings suggest that TCC is a worthy complementary non-pharmacological resource towards depression and anxiety and, thus, has great implications for the public health domain.

This paper examines the underlying meanings of salahoen, flying betel nut, and kaikaeo, the beautiful wild rooster, in “Lilit Phra Lo” or “The Tale of King Lo”. “Salahoen” and “kaikaeo” are usually considered magical items sent by Pu Chao Saming Phrai, the Green Mountain Guardian, to aid Princess Phuean and Princess Phaeng in fulfilling their desire of acquiring King Lo’s love. By using an anthropological approach, this study suggests that the “salahoen” might be an ordinary betel nut. It is a symbol of the princesses’ love for King Lo, their invitation and gestures of warm welcome. As soon as King Lo receives these messages from the two princesses, whom he also desires romantically, he decides without any hesitation to leave his city to pursue his love. The custom of sending a betel nut as a symbol of love, invitation, and warm welcome as found in this tale is practiced among Tai people including Thais and various other peoples in Southeast Asian countries. In a similar vein, this study also claims that the “kaikaeo” may be interpreted as an ordinary wild rooster whose significance lies in its roles in King Lo’s life and destiny. As this paper reveals, King Lo wants to have the “kaikaeo” to relieve his anxiety and despair after receiving a bad prediction from the guardian of the Kalong River. The belief that a fowl may be used to take away one’s misfortune and to foretell human fate exists in Thai and other Tai societies. Having unveiled the significance of the flying betel nut and the beautiful wild rooster in “the Tale of King Lo” from a cultural/anthropological perspective, this study then demonstrates that King Lo is fully aware of his actions–a factor that enables him to be a great tragic hero.

Reducing animal handling and costs in timed artificial insemination (TAI) systems are of great interest in animal production, regardless of the species. Thus, this study was carried out to investigate the effects of administering oestradiol cypionate (EC) or hCG to induce ovulation in buffalo (Bubalus bubalis) in TAI programs. The 79 Bufalipso heifers housed at Institute of Animal Science, San José de las Lajas, Cuba, were, on average, 24 months of age with a body weight of 310 to 380 kg at the beginning of the experiment. The investigation was conducted out of the breeding season (25 June through 28 July 2012). Heifers were randomly assigned to 1 of 3 treatment groups; either hCG (control group) or EC1 and EC2, in which TAI was performed at either 48 or 56 h after the EC injection, respectively. On the first day of the treatment regime (Day 0), animals received oestradiol benzoate (2 mg i.m.; Sincrodiol®, Ourofino, Brazil), followed by the insertion of an intravaginal device containing 1 g of progesterone (Primer®, Tecnopec, São Paolo, Brazil). On Day 9, an intramuscular luteolytic dose of cloprostenol (500 μg; Ciosin®, Intervet, Brazil) and eCG (500 UI; Novormon®, Intervet) were given in all heifers along with the removal of the intravaginal device. On the same day, 0.5 mg of EC (ECP®, Pfizer, Brazil) was administered intramuscularly in the EC1and EC2 groups. Animals in the hCG group received hCG (1000 IU i.m.; Vetecor®, Hertape Calier, Spain) on Day 11 and were inseminated 14 h later. Pregnancy diagnosis was performed by ultrasound 35 days after TAI. Data were analysed by a chi-squared test, with P < 0.05 taken as significant. There were no differences among treatment groups, with values of 57.7 (15/26), 60.7 (17/28), and 64% (16/25) for the EC1, EC2, and hCG groups, respectively. In conclusion, oestradiol cypionate was effective at inducing ovulation in buffalo heifers in TAI programs comparable to the control group, as evidenced by the conception rates. In addition, animals subjected to the EC protocol pass just 3 times through the corral instead of 4 when receiving hCG, which decreases the animal handling and costs.

Abstract Technology holds great potential to support those aging with and into disability. Research and development efforts in the aging space (aging into disability) have traditionally focused on improving health conditions, whereas those in the disability space (aging with disability) have primarily focused on supporting activity and participation. Bridging these perspectives and approaches adds rich context to guide the development and evaluation of technology interventions. Examples of technology interventions that support activity and participation and thereby improve health outcomes for adults aging with mobility disabilities show the need for bridging. The Telewellness research study used videoconferencing to deliver an evidence-based tai chi intervention to small groups. The Digital Assistant study explored the potential of the Amazon Echo to support controlling the home environment, engaging in physical activity, interacting with others, and managing health. Both projects offer credence to the value of supporting adults aging-in-place with wide range of capabilities and limitations. Part of a symposium sponsored by the Lifelong Disabilities Interest Group.

This article introduces a new framework for therapists to develop an exercise program to delay mobility disability in people with Parkinson disease (PD). Mobility, or the ability to efficiently navigate and function in a variety of environments, requires balance, agility, and flexibility, all of which are affected by PD. This article summarizes recent research identifying how constraints on mobility specific to PD, such as rigidity, bradykinesia, freezing, poor sensory integration, inflexible program selection, and impaired cognitive processing, limit mobility in people with PD. Based on these constraints, a conceptual framework for exercises to maintain and improve mobility is presented. An example of a constraint-focused agility exercise program, incorporating movement principles from tai chi, kayaking, boxing, lunges, agility training, and Pilates exercises, is presented. This new constraint-focused agility exercise program is based on a strong scientific framework and includes progressive levels of sensorimotor, resistance, and coordination challenges that can be customized for each patient while maintaining fidelity. Principles for improving mobility presented here can be incorporated into an ongoing or long-term exercise program for people with PD.

Ovarian follicular cysts are a major reproductive failure in lactating dairy cows, prolonging the calving-to-conception interval and resulting in great economic loss. Treatment with GnRH is currently the most common therapy used for ovarian follicular cysts in dairy cows, but definitive results remain inconclusive. Recently, the Ovsynch protocol has been introduced as a therapeutic strategy for ovarian cysts in dairy cows (Bartolome et al. 2000 Theriogenology 53, 815–825). The objective of the present study was to evaluate the therapeutic effect of a CIDR-based timed AI (TAI) protocol on ovarian follicular cysts in lactating Holstein cows. Lactating Holstein cows with ovarian follicular cysts were randomly assigned to two treatments: (1) insertion of a CIDR intravaginal progesterone device (CIDR™, InterAg, Hamilton, New Zealand) with an injection of 100 μg GnRH (Conceral®, Dongbang Co., Seoul, Korea) on Day 0, an injection of PGF2α (Lutalyse®, Pharmacia & Upjohn, Puurs, Belgium) and removal of the device on Day 7, an injection of GnRH on Day 9, and TAI 16 h after the GnRH injection (CIDR+GnRH-PGF2α-GnRH group, n = 30); and (2) an injection of 100 μg GnRH on Day 0, and AI at estrus (AIE) within 2 months after treatment with GnRH (GnRH group, n = 72). Day 0 was the day of initiation of the experiment. Pregnancy diagnosis was determined at 60 days after AI using both ultrasonography and rectal palpation. Pregnancy rates between groups were compared by chi-square analysis. Treatment-to-conception interval for cows that conceived by 150 days post-treatment was compared by Student's t-test. The pregnancy rate after TAI following the CIDR+GnRH-PGF2α-GnRH protocol (46.7%) was higher (P < 0.05) than that after AIE following GnRH injection (25.0%). The treatment-to-conception interval (mean ± SEM) was shorter (P < 0.01) in the CIDR+GnRH-PGF2α-GnRH group (46 ± 12 days) than in the GnRH group (88 ± 10 days), representing 21.9% more cows being pregnant by 150 days after treatment. These results indicate that the CIDR-based TAI protocol can be used as an efficient therapeutic tool for ovarian follicular cysts in lactating dairy cows. Follicular dynamics and endocrine changes during the CIDR+GnRH-PGF2α-GnRH protocol is being determined to clarify the beneficial outcome in this study. This work was supported by a Chungbuk National University Grant in 2004.

AbstractPremenstrual syndrome (PMS) is a very common condition leading to physical, emotional, and psychological distress in females during their reproductive years. Researchers found that as many three of every four menstruating women have experienced some form of PMS. Although the severity of this problem is great, a lot of confusion exists in both medical and lay communities about what is and is not effective for the treatment of PMS. It has a wide variety of signs and symptoms and it may tend to recur in a predictable pattern. The physical and emotional changes experienced with PMS may vary from just slightly noticeable to very intense. Lifestyle adjustments in every kind can help to reduce or manage the signs and symptoms of PMS. Apart from all these, one of the most beneficial methods to reduce the difficulties of PMS is relaxation therapy which includes meditation, visualization, autogenic, Tai Chi, hydrotherapy, exercise, massage, aromatherapy, biofeedback, relaxation breathing, progressive muscle relaxation (Jacobson’s progressive relaxation therapy and The Mitchells progressive relaxation therapy) and yoga. Thus when remedies are available why not we celebrate the inborn power of relieving PMS in women.

Parkinson's disease is one of the most common neurodegenerative diseases. Given the progressive course and numerous motor and motor symptoms, this disorder can significantly affect person's functional status, quality of life, and disability. Possibility of treatment and prevention of parkinsonism varies depending on the type of Parkinson's disease. Medication, physical therapy and surgical treatment are used. Effective pharmacologic therapy includes comprehensive physical therapy and rehabilitation, starting at the time of diagnosis. It can prevent and treat complications, slow the progression of symptoms, and enhance adaptation to the newly acquired condition. It is necessary to stimulate mechanisms of compensation and neuroplasticity. Experiences show that kinesiotherapy and physical agents are effective in the treatment of pain, walking disorders, postural instability and risk of falls. There are also alternative techniques such as yoga, tai chi, acupuncture, dance therapy, music therapy that have a positive impact on the disease. The efficacy of neurofeedback, art therapy in improving and maintaining cognitive functions has been demonstrated. Occupational therapy is of great importance for empowering the patient with activities of daily living, especially for self-care. Education and support from family and carers, as well as home and workplace adaptation, play an important role in rehabilitation. Rehabilitation and physical therapy for this disease is carried out systematically and for a lifetime. A multidisciplinary approach in treating patients with Parkinson's disease enables the maintenance of quality of life.

Abstract A growing number of new smart, internet-enabled technologies from smart phone applications, to teleconferencing, to the Internet of Things (IoT), provide great promise and potential to support successful aging-in-place for people with long-term disabilities. This symposium highlights ongoing research at the TechSAge Rehabilitation Engineering Research Center to identify technology needs and develop/adapt new technologies to promote independence, health, and participation of this population. To understand user needs, Harris et al. will present findings from a large-scale interview study with older adults with long-term vision and mobility disabilities (N=120) that explored specific task-based challenges with community activities (e.g., going to entertainment events, volunteering) as well as solutions and strategies to overcome them. Koon et al. will present findings on perceived facilitators and barriers to using digital assistants (e.g., Amazon Alexa) to facilitate a variety of everyday tasks at home, from shopping to communicating with others, among adults aging with mobility disabilities. Levy et al. will discuss findings from research driving the creation of augmented reality tools that can enable individuals to experience how IoT devices, such as smart thermostats and lightbulbs, could be used within the context of one’s own abilities and home. Mitzner et al., will describe the development of a Tele Tai Chi intervention for older adults with long-term mobility disabilities that employs teleconferencing software to translate an in-person, evidence-based class to an online, social experience. TechSAge Program Officer, Sarah Ruiz (National Institute on Disability, Independent Living, and Rehabilitation Research), will serve as the discussant.

Abstract The increasing diversity in the aging population warrants systematic investigations regarding ethnic differences related to cognitive aging and ethnicity-unique risk factors. However, due to the great paucity of population-based longitudinal data on cognitive aging in racial/ethnic minority populations, our knowledge in this area remain limited. The purpose of this symposium is, therefore, to examine various psychological, socio-cultural, and physical factors associated with cognitive aging among U.S. Chinese older adults, representing one of the biggest and fastest growing older minority populations nationally. Using longitudinal data from a population-based prospective cohort study, namely The Population Study of ChINese Elderly in Chicago (PINE) with a sample size of 3,157, this symposium presents findings from five research projects. Session 1 investigates the relationship between psychological well-being and change of cognitive function over four years. Session 2 and 3 examine the relationships between two socio-cultural factors and cognitive function. Specifically, session 2 investigates the associations between immigration-related factors and the incidence of cognitive impairment. Session 3 explores the relationship between cognitive function and Tai-Chi practice. Session 4 and 5 examine the relationships between two physical health indicators and cognitive aging. Specifically, session 4 examines the relationship between physical function and change of cognitive function over two years. Session 5 explores the association between body mass index and cognitive function decline over two years. Taken together, this symposium aims to further our knowledge of cognitive aging among ethnically/culturally diverse populations. The research findings will identify unique factors related to cognitive aging in older minority populations.

Physical exercise is considered an effective means to stimulate bone osteogenesis in osteoporotic patients. The authors reviewed the current literature to define the most appropriate features of exercise for increasing bone density in osteoporotic patients. Two types emerged: (1) weight-bearing aerobic exercises, i.e., walking, stair climbing, jogging, and Tai Chi. Walking alone did not appear to improve bone mass; however it is able to limit its progressive loss. In fact, in order for the weight-bearing exercises to be effective, they must reach the mechanical intensity useful to determine an important ground reaction force. (2) Strength and resistance exercises: these are carried out with loading (lifting weights) or without (swimming, cycling). For this type of exercise to be effective a joint reaction force superior to common daily activity with sensitive muscle strengthening must be determined. These exercises appear extremely site-specific, able to increase muscle mass and BMD only in the stimulated body regions. Other suggested protocols are multicomponent exercises and whole body vibration. Multicomponent exercises consist of a combination of different methods (aerobics, strengthening, progressive resistance, balancing, and dancing) aimed at increasing or preserving bone mass. These exercises seem particularly indicated in deteriorating elderly patients, often not able to perform exercises of pure reinforcement. However, for these protocols to be effective they must always contain a proportion of strengthening and resistance exercises. Given the variability of the protocols and outcome measures, the results of these methods are difficult to quantify. Training with whole body vibration (WBV): these exercises are performed with dedicated devices, and while it seems they have effect on enhancing muscle strength, controversial findings on improvement of BMD were reported. WBV seems to provide good results, especially in improving balance and reducing the risk of falling; in this, WBV appears more efficient than simply walking. Nevertheless, contraindications typical of senility should be taken into account.

Abstract Introduction: The assessment of functional fitness of older people, who took part in different forms of activities e.g. in programs which are offered by UTW, together with the information about the fitness level, can have a great importance in optimization of motor activation of older people. The aim of this study is to evaluate the changes in the level of functional fitness and basic parameters of the anthropometric parameters of older women after 16-weeks activity program offered by University of the Third Age (UTW) at the Józef Piłsudski University of Physical Education in Warsaw. Material and methods: Ten women at the age of 72,0±5,40 who attended UTW 1,7±0,48 years took part in the study. Women participated in the activities 2-3 a week, and the major activities were Nordic Walking and gymnastics. Moreover they had a chance to attend Tai Chi, swimming and dancing classes. The Fullerton Functional Fitness Test was used to assess women’s functional fitness. Test was done twice - during the second week and at the end of first semester. Results were evaluated with the usage of norms described for particular test trials and age groups (Jones and Rikli 2002). Measurements and evaluation of basic anthropometric parameters were done as well as Body Mass Index was calculated. Results: At the end of the cycle of activities, it turned out that women achieved better results during the fitness tests than they had after the first test. During evaluation with the usage of norms of Fullerton Fitness Test good level of aerobic endurance, strength and coordination of tested women was noted, however the flexibility test results gave evidence of negligence in this area. It was also discovered that participation in the cycle of physical activities might have been one of the elements that caused positive, considering health, changes in anthropometric parameters of tested women. Reducing of the body mass and the percentage of the fat tissue and regular physical activity had an influence on lean body mass increase. onclusions: Physical activities done by UTW participants during the program, where the major activities were Nordic Walking and gymnastics, had the influence on improvement of their fitness and positive changes in their anthropometric parameters.

Purpose: To systematically evaluate the effects of mind-body exercises (Tai Chi, Yoga, and Health Qigong) on motor function (UPDRS, Timed-Up-and-Go, Balance), depressive symptoms, and quality of life (QoL) of Parkinson’s patients (PD). Methods: Through computer system search and manual retrieval, PubMed, Web of Science, The Cochrane Library, CNKI, Wanfang Database, and CQVIP were used. Articles were retrieved up to the published date of June 30, 2019. Following the Cochrane Collaboration System Evaluation Manual (version 5.1.0), two researchers independently evaluated the quality and bias risk of each article, including 22 evaluated articles. The Pedro quality score of 6 points or more was found for 86% (19/22) of these studies, of which 21 were randomized controlled trials with a total of 1199 subjects; and the trial intervention time ranged from 4 to 24 weeks. Interventions in the control group included no-intervention controls, placebo, waiting-lists, routine care, and non-sports controls. Meta-analysis was performed on the literature using RevMan 5.3 statistical software, and heterogeneity analysis was performed using Stata 14.0 software. Results: (1) Mind-body exercises significantly improved motor function in PD patients, including UPDRS (SMD = −0.61, p < 0.001), TUG (SMD = −1.47, p < 0.001) and balance function (SMD = 0.79, p < 0.001). (2) Mind-body exercises also had significant effects on depression (SMD = −1.61, p = 0.002) and QoL (SMD = 0.66, p < 0.001). (3) Among the indicators, UPDRS (I2 = 81%) and depression (I2 = 91%) had higher heterogeneity; according to the results of the separate combined effect sizes of TUG (I2 = 29%), Balance (I2 = 16%) and QoL (I2 = 35%), it shows that the heterogeneity is small; (4) After meta-regression analysis of the age limit and other possible confounding factors, further subgroup analysis showed that the reason for the heterogeneity of UPDRS motor function may be related to the sex of PD patients and severity of the disease; the outcome of depression was heterogeneous. The reason for this may be the use of specific drugs in the experiment and the duration of intervention in the trial. Conclusion: (1) Mind-body exercises were found to have significant improvements in motor function, depressive symptoms, and quality of life in patients with Parkinson’s disease, and can be used as an effective method for clinical exercise intervention in PD patients. (2) Future clinical intervention programs for PD patients need to fully consider specific factors such as gender, severity of disease, specific drug use, and intervention cycle to effectively control heterogeneity factors, so that the clinical exercise intervention program for PD patients is objective, scientific, and effective.

<p>A model for long-term analysis of the influence of timber production on lichens for reindeer grazing (Cladina, Alectoria, Bryoria spp and others) in Sweden is presented. The annual production of and demand for lichens are estimated and compared. Production of these lichens is presumed to set the upper limit for the reindeer population. Reindeer graze on both ground and tree lichens, which both must be accessible in sufficient amounts and at the right times of the year if reindeer husbandry is to succeed without supplementary feeding. The model is based mainly on existing data, and uses are estimations from the National Forest Survey and the Hugin system for calculation of longterm potential cut (Bengtsson, 1981). Geographically the study is limited to Vasterbotten and Norrbotten, the northernmost counties in Sweden, where most reindeer husbandry in Sweden is located, and where reindeer grazing takes place over almost the whole area. The calculations cover a period of one hundred years from 1980, and are based on a timber production programme which relies more on &laquo;multiple use&raquo; than the current Swedish forest policy (Bengtsson, 1986). The annual production of ground lichens is calculated by multiplying the area covered with ground lichens by their increment as estimated from their rate of biomass increase, which in turn depends on site factors and age of the stand. The estimation of the area is based on data from the National Forest Survey. Sample plots with ground lichens are assumed to maintain lichens during the whole hundred year period. Areas with stands that have been thinned within ten years and stands younger than 20 years are excluded due to logging residues from thinnings and packed snow. Some of the remaining area cannot practically be utilized for reindeer grazing. Representatives of three communities of reindeer herders classified 212 plots from the National Forest Survey with ground lichens and assessed that 3/4 of the plots can be utilized. The reduction was because of location (near buildings, roads, railroads, and recreation facilities), or because the area with lichens was too small and isolat&eacute;d. Demand for ground lichens is calculated as the daily demand for ground lichens by the reindeer multiplied by the number of days every year that reindeer depend on this forage. Figures used are based upon estimations from persons with great experience of reindeer farming. The annual production of tree lichens consists of two parts, i.e., tree lichens within reach of the reindeer, and tree lichens which become accessible after falling down from the trees onto the snow. Forest stands dominated by conifers and older than one hundred years are assumed to bear tree lichens. This area is also reduced to 75 per cent for reasons of practical accessibility. Annual production of lichens in reach of the reindeer is then estimated as the area multiplied by the increment rate of the biomass. One quarter of the annually fallen tree lichens is assumed to be available as fodder during late winter/early spring. The demand for tree lichens is principally estimated in the same way as for ground lichens, but the number of days per years is lower because tree lichens are mainly considered to be fodder in distress periods. Two sources of uncertainty are present in the results, namely the influence of factors not included in the models, and the influence of uncertainty in factors included in the models. The models used to estimate production and demand obviously imply simplifactions of true relations. These simplifications are mainly due to a basic lack of knowledge, one example being that variation, i.e. in volume per hectare, might very well influence the production of lichens, but is not taken into consideration in the models. One example of uncertainty in data used is the increment rate of lichen fodder. Another example is the estimation of biomass of lichens, here based upon investigations (Eriksson, unpubl.) with other purposes than to provide data about grazing availability in the large geographic regions used in this study. The possibilities for drawing reliable conclusions will increase when better estimations of input data and relationship are available. The geographic division into four regions is a result of the design of the National Forest Survey. However, great differences may be present within these geographic areas, each containing a number of communities of reindeer herders. Thus, results are not applicable to single communities of reindeer herders. The study illustrates a method of revealing how lichen fodder for reindeer will develop in relation to timber production. The results of the calculations, however, are too uncertain to allow reliable conclusions to be drawn. Nonetheless, the results indicate that in some areas there is already a shortage of lichen fodder for the number of reindeer assumed in this study. The calculations hint that production will decrease in the future. These indications should motivate more research in this topic. If the results of this study are accurate and if forestry develops according to the assumptions, the owners of the reindeer will have to continue or increase the supplementary feeding and/or reduce the number of reindeer significantly. They will also have to utilize all of the areas that are possible to graze, even if some of them today are considered to be of marginal value for reindeer grazing. Another way to improve the balance of production and demand is to adjust forest management on areas with lichens to a greater extent than has been done in the timber production alternative analysed in this study.</p><p>Virkesproduktionens inverkan p&aring; renskotselns lavbete - En metodstudie.</p><p>Abstract in Swedish / Sammanfattning: En modell for l&aring;ngsiktig analys av virkesproduktionens inverkan p&aring; renskotselns lavbete(Cladina, Alectoria, Bryoria spp mfl) i Sverige presenteras. Modellen ber&aring;knar &aring;rlig produktion och behov av lavbete, ef^ersom tillg&aring;ngen p&aring; dessa lavar bedoms begr&aring;nsa renpopulationen. B&aring;de tr&aring;d- och marklavar betas av renarn&pound;| och m&aring;ste finnas tillg&aring;ngliga i tillr&aring;cklig m&aring;ngd och vid r&aring;tt tidpunkt under &aring;ret om renskotseln skall klara sig utan stodutfordring. Modellen bygger huvudsakligen p&aring; redan existerande data. Skattningarna av areal gors med data fr&aring;n riksskogstaxeringen och fr&aring;n ber&aring;kningar med Hugin-systemet for l&aring;ngsiktiga analyser av avverkningsmojlighe-terna (Bengtsson, 1981). Studien begr&aring;nsas geografiskt till Norr- och V&aring;sterbottens l&aring;n. Ber&aring;kningarna gors for en hun^ra&aring;rsperiod med start 1980, och bygger p&aring; ett virkesproduktionsprogram i A VB-85 som syftar till mera m&aring;ngbruk an dagens skogspolitik (Bengtsson, 1986). Den &aring;rliga produktionen av marklav skattas som produkten av m&aring;ngden marklav per hektar, dess till-v&aring;xtprocerit och arealen med marklav. M&aring;ngden marklav per hektar beror av st&aring;ndortsforh&aring;llanden och bes-t&aring;nds&aring;ldern. Skattningen av arealen baseras p&aring; uppgifter fr&aring;n riksskogstaxeringen. Provytor med marklav antas vara layb&aring;rande under hela prognosperioden. Provytor d&aring;r best&aring;nds&aring;ldern &aring;r l&aring;gre &aring;n 20 &aring;r, samt provytor som i awerkningsber&aring;kningen rojts eller gallrats under senaste tio&aring;rsperiod r&aring;knas dock bort. Orsaken &aring;r att snopacknirig och kvarl&aring;mnade stammar och ris forsv&aring;rar eller omojliggor for renen att komma &aring;t laven. Hela den &aring;terst&aring;ende arealen kan dock inte nytt jas for planerad renskotsel. Representanter for tre samebyar bedomd)e 212 av riksskogstaxeringens provytor med marklav med avseende p&aring; om de kan nytt jas for planerad renskotsel. Resultatet blev att 3/4 av provytorna ans&aring;gs kunna utnyttjas. Provytor r&aring;knades bort p&aring; grund av bel&aring;genlhet n&aring;ra byggnader, v&aring;gar, j&aring;rnv&aring;gar och friluftsanl&aring;ggningar, eller pga att arealen med marklav var for liten och isolerad for att kunna utnyttjas. Behovet av marklav ber&aring;knas som produkten av det genomsnittliga dygnsbehovet for en ren, antalet renar samt det ailital dagar per &aring;r som renarna bedoms ha behov av detta foder. De tv&aring; senare uppgifterna grundas p&aring; uppskattningar av personer med stor erfarenhet av renskotsel. Den &aring;rliga produktionen av tr&aring;dlavar best&aring;r dels av lavtillv&aring;xten i det betningsbara hojdintervallet, dels av tr&aring;dlav som faller ner p&aring; snon. Barrdominerade best&aring;nd aldre &aring;n hundra &aring;r antas vara tr&aring;dlavb&aring;rande, men &aring;ven denna areal reduceras med h&aring;nsyn till praktisk tillg&aring;nglighet. &Aring;rlig produktion av tr&aring;dlav inom r&aring;ckh&aring;ll for renen skattas som produkt av m&aring;ngden tr&aring;dlav, dess tillv&aring;xtprocent och arealen. Av den tr&aring;dlav som &aring;rli-gen faller n)er p&aring; marken antas en fj&aring;rdedel vara tillg&aring;nglig under v&aring;rvintern. Efterfr&aring;gan p&aring; tr&aring;dlav ber&aring;knas p&aring; i princip samma s&aring;tt som efterfr&aring;gan p&aring; marklav, men antal betningsda-gar per &aring;r &aring;k l&aring;gre eftersom tr&aring;dlav huvudsakligen &aring;r ett visserligen hogkvalitativt och l&aring;ttillg&aring;ngligt, men dock nodfoder. Resultaten &aring;r os&aring;kra av tv&aring; huvudorsaker. Dels pga inverkan av faktorer som inte ing&aring;r i modellen, dels os&aring;kerhetejn i de faktorer som ing&aring;r i modellen. Modellen inneh&aring;ller uppenbart forenklingar av verkliga samband. Dessa forenklingar beror huvudsakligen p&aring; viss brist p&aring; grunddata. Mojligheterna att dra s&aring;kre slutsatser kommer att oka i takt med b&aring;ttre kunskap om utnyttjade samband och uppgifter. Den geografiska indelningen i l&aring;nsdelar beror p&aring; utformningen av riksskogstaxeringen. Forh&aring;llandena kan givetvis variera inom dessa l&aring;nsdelar, som var och en best&aring;r av ett flertal samebyar. Resultaten f&aring;r s&aring;ledes inte till&aring;mpas p&aring; enskilda samebyar. Studien visar p&aring; en metod for att belysa hur renskotselns lavbete kommer att utvecklas i relation till virkes-produktionen. Resultaten &aring;r dock allt for os&aring;kra for att man skall kunna dra n&aring;gra s&aring;kra slutsatser. Resultaten antyder emellertid att for vissa omr&aring;den finns redan i dag en brist p&aring; lavbete for den renpopulation som kalkylerats med i denna studie. Ber&aring;kningarna antyder att produktionen av lavbete kommer att minska i framtiden, vilket bor motivera mer forskning inom omr&aring;det. Om resultaten i denna studie &aring;r riktiga och om det virkesproducerande skogsbruket utvecklas enligt exemplet, m&aring;ste ren&aring;garna forts&aring;tta med eller utoka stodutfodringen och/eller minska antalet renar betydligt. De tvingas ocks&aring; utnyttja alla betningsbara omr&aring;den, &aring;ven s&aring;dana som for n&aring;rvarande anses vara marginella. Ett annat s&aring;tt att forb&aring;ttra balansen &aring;r att modifiera det virkesproducerande skogsbruket p&aring; arealer med lavbete i storre utstr&aring;ckning &aring;n vad som gors i det alternativ som analyseras h&aring;r.</p><p>Puuntuotannon vaikutus j&auml;k&auml;l&auml;laitumiin.</p><p>Abstract in Finnish / Yhteenveto: Artikkelissa esitet&aring;&aring;n pitk&aring;naikav&aring;lin analyysimalli puuntuotannon vaikutuksista ruotsin j&aring;k&aring;l&aring;-laitumille (Cladina, Alectoria, Bryoria spp. ym.). Koska j&aring;k&aring;lien saantia pidet&aring;&aring;n porojenlukum&aring;&aring;r&aring;&aring; rajoittava, laskee malli j&aring;k&aring;l&aring;laidunten vuotuisen tuoton ja tarpeen. Porot laiduntavat sek&aring; puussa ett&aring; maassa kasvavia j&aring;k&aring;li&aring;, ja nit&aring; molempia on oltava saatavilla, sek&aring; tarvittava m&aring;&aring;r&aring;, ett&aring; oikeaan aikaan vuodesta, jos poronhoito aikoo selviyty&aring; ilman tukiruokintaa. Malli rakentuu p&aring;&aring;siassa jo aikaisemmin hankittuihin tietoihin. Pinta-ala arviot tehd&aring;&aring;n valtakunnanmets&aring;narvioinnin tietojen, ja hakkuumahdollisuuksien pitk&aring;naikav&aring;lin analysoimiseksi perustetun Hugin-systeemin laskelmien avulla (Bengtsson, 1981). Maantieteellisesti tutkielma rajoittuu Norrbotte-nin ja V&aring;sterbottenin l&aring;&aring;neihin. Laskelmat tehd&aring;&aring;n sadanvuoden aikav&aring;lille alkaen 1980, perustuen yhteen AVB-85:en puuntuotantoohjelmaan, joka t&aring;ht&aring;&aring; t&aring;m&aring;np&aring;iv&aring;ist&aring; laajempaan metsien moninaisk&aring;yttoon (Bengtsson, 1986). Vuotuinen maassa kasvavien j&aring;k&aring;lien tuotanto arvioidaan j&aring;k&aring;lien hehtaarim&aring;&aring;rien, sen kasvuprosentin ja pinta-alan tulona. J&aring;k&aring;lien m&aring;&aring;r&aring; hehtaaria kohti on riippuvainen kasvupaikan ja metsikon i&aring;st&aring;. Pinta-ala arviot perustuvat valtakunnanmets&aring;narvioinnin tietoihin. J&aring;k&aring;l&aring;&aring; kasvavien koealojen odotetaan pit&aring;v&aring;n j&aring;k&aring;-l&aring;kasvustonsa koko prognoosiajan. Koealat, joissa metsikon ik&aring; on alle 20 vuotta, sek&aring; koealat, jotka hak-kuulaskelmissa on perattu tai harvennettu viimeisen kymmenen vuoden aikana, on j&aring;tetty huomioimatta. Syyn&aring; t&aring;h&aring;n on lumenpakkaantuminen, sek&aring; j&aring;ljelle j&aring;tetyt rungot ja oksat, jotka vaikeuttavat tai tekev&aring;t po-rojen j&aring;k&aring;l&aring;n saannin mahdottomaksi. Vuotuinen puussa kasvavien j&aring;k&aring;lien tuotanto koostuu, osittain poron ulottuvilla olevasta, ja osittain lu&not;melle putoavasta jak&aring;l&aring;st&aring;. Yli sata vuotta vanhojen havupuuvaltaisten metsikkojen oletetaan tuottavan puussa kasvavia j&aring;k&aring;li&aring;, mutta myos t&aring;m&aring; pinta-ala pienenee k&aring;yt&aring;nnon syist&aring;. Vuotuinen poronulottuvilla puussa kasvavien j&aring;k&aring;li&aring; tuotanto arvioidaan j&aring;k&aring;l&aring;n m&aring;&aring;r&aring;n, sen kasvuprosentin ja pinta-alan tulona. Yksi nelj&aring;nnesosa siit&aring; vuosittain lumelle tippuvasta j&aring;k&aring;l&aring;m&aring;&aring;r&aring;st&aring; oletetaan olevan saatavilla kev&aring;ttalvella. Puussa kasvavien j&aring;k&aring;lien kysynt&aring; lasketaan periaatteessa samalla tavoin kuin maassa kasvavien j&aring;k&aring;lien ky-synt&aring;, paitsi ett&aring; vuorokausien m&aring;&aring;r&aring; vuodessa on pienempi, koska puussa kasvavavien j&aring;k&aring;lien katsotaan p&aring;-&aring;asiassa olevan h&aring;t&aring;ravintoa. Tulokset ovat ep&aring;varmoja kahdesta p&aring;&aring;syyst&aring;. Osittain niiden tekijoiden vuoksi, jotka eiv&aring;t sis&aring;lly malliin, osittain niiden tekijoiden ep&aring;tarkkuudesta, jotka sis&aring;ltyv&aring;t malliin. Malli sis&aring;lt&aring;&aring; selvi&aring; todellisten yhteyksien yksinkertaistamisia. N&aring;m&aring; yksinkertaistamiset johtuvat p&aring;&aring;asiassa perustietojen puutteesta. Esimerkkin&aring; voidaan mainita, ett&aring; mets&aring;n tila muuttuu paljolti prognoosikauden aikana. T&aring;t&aring; vaihtelua esimerkiksi puus-tossa ei kuitenkaan mallissa huomioida. Esimerkki niiden tekijoiden ep&aring;tarkkuudesta, jotka sis&aring;ltyv&aring;t malliin, on j&aring;k&aring;l&aring;laidunten kasvuprosentti. Toinen esimerkki on j&aring;k&aring;l&aring;m&aring;&aring;rien arviot, jotka t&aring;ss&aring; perustuvat tutkielmiin (Eriksson, julkaisematon), joilla on ollut toinen tarkoitusper&aring; kuin t&aring;ss&aring; tutkimuksessa k&aring;sitelt&aring;vien l&aring;&aring;ninosien laiduntamahdollisuuksien arvioiminen. Mahdollisuudet varmojen johtop&aring;&aring;tosten tekoon lis&aring;&aring;ntyv&aring;t yhdess&aring; parempien perustietojen myot&aring; k&aring;ytetyist&aring; yhteyksist&aring; ja tiedoista. Maantieteellinen jako l&aring;&aring;ninosiin johtuu valtakunnanmets&aring;narvioinin rakenteesta. Olosuhteet voivat tie-tysti vaihdella n&aring;iden l&aring;&aring;ninosien sis&aring;ll&aring;, joista jokainen sis&aring;lt&aring;&aring; useamman paliskunnan. Tuloksia ei siis saa tulkita paliskunta kohtaisesti. Tutkielma esitt&aring;&aring; tavan valoittaa kuinka porohoidon j&aring;k&aring;l&aring;laitumet kehittyv&aring;t suhteessa puuntuotantoon. Tulokset ovat kuitenkin liian ep&aring;varmoja, jotta niist&aring; voitaisiin vet&aring;&aring; varmoja loppup&aring;&aring;telmi&aring;. Tulokset viittaavat kuitenkin, ett&aring; tietyill&aring; alueilla on jo talla hetkell&aring; pula j&aring;k&aring;l&aring;laitumista niill&aring; porom&aring;&aring;rill&aring;, joilla tassa tutkielmassa on laskettu. Laskelmat viittaavat, ett&aring; tuotanto v&aring;henee tulevaisuudessa, mink&aring; pit&aring;isi motivoida laajempaa tutkimukseen t&aring;ll&aring; alueella. Jos tulokset t&aring;ss&aring; tutkimuksessa ovat oikeat ja jos puuntuotannollinen mets&aring;talous kehittyy esimerkin mu-kaisesti, pit&aring;&aring; poronomistajien jatkaa tai lis&aring;t&aring; tukiruokintaa ja/tai v&aring;hent&aring;&aring; porojen lukum&aring;&aring;r&aring;&aring; huomatta-vasti. He joutuvat my os hyodynt&aring;m&aring;&aring;n kaikki laiduntamiskelpoiset alueet, my os sellaiset jotka t&aring;ll&aring; hetkell&aring; ovat v&aring;hemm&aring;n t&aring;rkeit&aring;. Toinen tapa par ant aa tasapainoa on sopeuttaa j&aring;k&aring;l&aring;alueiden puuntuotannollinen mets&aring;talous suuremmassa m&aring;&aring;rin kuin t&aring;ss&aring; analysoitavassa vaihtoehdossa tehd&aring;&aring;n.</p>

Disk brakes were first introduced on the suburban and urban coaches and high speed freight cars (V > 120 km/h) for the following reasons: shoe brakes reached their potential limits, especially at high speeds; the maintenance of disc brakes is cheaper; greater comfort; the friction coefficient of disk brake elements (friction pad and brake disc) presents lower variation in velocity and pressure; disk brakes present lower temperatures of friction surfaces. The determination of uniform heat flow through the friction elements of disk brakes is very important since the early designing stage. Such way one avoids overheating both disk brakes and friction pads that may result when the physical properties (chemical and mechanical) of materials are not correctly matched and have negative effects on braking efficiency (small coefficient of friction, large braking distance etc.) This work studies the influence of braking time (30 s, 40 s, 50 s, 60 s) on the uniform heat flow of the friction element surface. Note that in the same area of disk brake friction 0.4 m2, heat flow decreases with an increased duration of braking, leading to longer braking space. At the same time, if pressure on the pad of disk brake friction decreases, heat flow increases. Santrauka Pirmą kartą diskiniai stabdžiai buvo panaudoti sausumos transporto priemonėse (taip pat ir geležinkelio) dėl tokių priežasčių: būgninių stabdžių kaladėlės nusidėvi, ypač esant dideliems greičiams; diskinių stabdžių remonto darbams reikia skirti mažiau išlaidų; diskiniai stabdžiai patogesni; didelis diskinių stabdžių stabdymo efektyvumas; mažesnė diskinių stabdžių trinties paviršių temperatūra stabdant. Labai svarbu nustatyti šilumos srautą, sklindantį per diskinių stabdžių elementus trinties metu dar ankstyvuoju projektavimo etapu. Tai padeda išvengti diskinių stabdžių ir greta jų esančių elementų perkaitimo, kuris gali atsirasti, kai medžiagos parinktos neteisingai ir pasikeitusios jų fizinės, cheminės ar mechaninės savybės po perkaitinimo daro neigiamą poveikį stabdymo efektyvumui (mažas trinties koeficientas, ilgas stabdymo kelias ir t. t.). Šiame straipsnyje nagrinėjama, kokią įtaką stabdymo laikas (30 s, 40 s, 50 s, 60 s) daro šilumos srautui į besitrinančius elementų paviršius trin Transport, 2011, 26(1): I a–I d I c ties (stabdymo) metu. Pažymėtina, kad toje pačioje diskinių stabdžių trinties srityje (stabdymo plotas—0,4 m2) šilumos srautas mažėja didėjant stabdymo trukmei ir todėl didėja stabdymo kelias. Tuo pat metu, jeigu diskinių stabdžių trinties sritis (stabdymo plotas) mažėja, šilumos srautas didėja. Резюме Дисковые тормоза впервые были применены в наземных транспортных средствах (в том числе и железнодорожных) из-за следующих причин – колодки барабанных тормозов быстро изнашиваются при больших скоростях, работы по ремонту дисковых тормозов требуют меньше затрат времени и средств, они более удобны и характеризуются большей эффективностью торможения, при торможении меньше нагреваются трущиеся поверхности. Очень важно на ранней стадии проектирования дисковых тормозов определить тепловой поток, образующийся из-за трения поверхностей элементов тормозов. Данная информация поможет предотвратить перегрев элементов самих дисковых тормозов и элементов, находящихся рядом с ними. Перегрев тормозов возможен из-за неправильно подобранных материалов их элементов. После перегрева изменившиеся физико-механические и химические свойства элементов тормозов могут отрицательно влиять на эффективность торможения (малый коэффициент трения, длинный путь торможения и т. д.). Автор исследует влияние времени торможения (30, 40, 50, 60 с) на тепловой поток, образующийся из-за трения поверхностей элементов дисковых тормозов во время торможения. Необходимо отметить, что при той же области трения элементов (площадь трения – 0,4 м2) тепловой поток уменьшается при увеличении времени торможения, поэтому увеличивается путь торможения. В то же время при уменьшении области трения элементов (площади трения) дисковых тормозов тепловой поток увеличивается.

The paper deals with the effects of prescriptivism on the Lithuanian language. The research includes one domain of language use – radio and television, and one aspect of language – lexicon, in the period between 1960 and 2010. The investigation is corpus-based and focuses on the use of words that are classified as “incorrect” by the Lithuanian norm-setters. The study is important both as a discussion of the impact of prescriptivism on language change in general, as well as of the indirect influence of media on language, since media can affect the symbolic evaluation of specific language forms.The paper consists of five chapters. The first chapter “Review of the research” discusses the theoretical assumptions and concepts needed for further analysis: it gives an overview of studies on the effects of prescriptivism conducted in Lithuania and elsewhere, presents the concepts of second-level indexicality and style, and outlines the key characteristics of media change in Lithuania that are relevant to the study. Studies on the success of prescriptivism do not give a definite answer as to whether prescriptivism works. Institutionalisation and a high degree of stigmatisation of the corrected language forms can be listed among the factors that increase its success; prescriptivism is likely to be less successful when the “forbidden” language forms are too convenient to be given up, or when prescriptivist rules are too complicated for lay language users and the rules contradict each other. In the case of media, the effect of prescriptivism is said to be weakened by media commercialisation.When applied to the analysis of non-standard words, first-order indexicality refers to situations when the non-standard forms are used as value-free instances of ordinary speech, in already established meanings; in these cases, the speakers are not aware that they are using “incorrect” forms. Second-order indexicality refers to cases when non-standard words are used for additional function, e.g., to express a speaker’s particular identity or to construct a certain (informal, friendly) speech style. The concept of style, referring to the social differences between individual speakers, is used to analyse the use of words in concrete situations. The paper gives an overview of three sociolinguistic concepts of style that are relevant in this study: style as a degree of formality (e.g., when the speaker accommodates to the formal context of the media and uses less non-standard words); as audience and referee design (e.g., use of non-standard words in programmes for young audiences); and as a speaker design (e.g., play with language by the programme host in order to construct a fun persona).In the study of non-standard lexis, it is important to account for certain features of Lithuanian media development, such as the Soviet period, which was characterised by the use of newspeak, and the commercialisation of the media in the contemporary period. Accordingly, the paper analyses the uses of incorrect words as a part of newspeak and their use for the entertainment-related purposes such as language plays in present times. The paper also addresses the transitory period of radio and TV development, which has features from both the previous and the later periods, as well as some unique characteristics of language use.The second chapter “Radio and TV speech in the prescriptive discourse” presents an analysis of the metalinguistic discourse on media speech produced by Lithuanian prescriptivists from the pre-war period up to now. The analysis shows how this discourse preserved the same dominant idea about media’s role in language standardisation. On the one hand, during this whole time, radio and television were approached as responsible for teaching listeners and viewers the “correct language”; on the other hand, simultaneously, the language of radio and television was perceived as failing to conform to the prescriptive norms set by the norm-setters. The huge societal shifts that happened during this time did not make a major influence on this discourse. It remained very stable during different periods of time. The social, cultural and political changes in society and the media were taken into account only by adjusting the argumentation – by presenting patriotic, moral, ideological or legal motives that were meant to justify the language prescriptions.The third chapter “Research methods and data” presents the Corpus of Radio and TV speech, the concept of non-standard words, and the sources of prescriptivist corrections used in the analysis. The corpus of radio and TV speech includes data from 1960 to 2011 and is constructed in a balanced way to represent the periods of Lithuanian radio and TV development (Soviet, transitory, contemporary), as well as programme genres (talk programmes, information programmes, journals/features/documentaries). The speakers are coded into six types: news reader/voice-over, talk show host, expert, celebrity, hero and vox populi. For the analysis, the non-standard words that are classified as “incorrect” in the normative tradition of the Lithuanian language were coded. These include old (mainly, Slavic) and new (mainly, English) loans, the so-called hybrid words (that have a borrowed part), semantic loans, translations, as well as some lexicalised uses of words and some lexicalised syntactic constructions. Two types of words are analysed – individual lexical words and functional words. The latter include various fillers and discourse markers, as well as pronoun constructions with tai (e.g. kažkas tai ‘some(body)’). Non-standard words were identified from older and present style guides, including the database of language corrections created by the State Commission of the Lithuanian Language.The fourth chapter “Change in the number of non-standard words: a quantitative analysis” investigates development of the use of non-standard words on radio and TV, as well as the frequency of usage of the non-standard lexical forms. According to the corpus data, the average frequency of non-standard words by one speaker is 17 per thousand words, which makes up about 2–3 “incorrect” words per minute. Non-standard discourse markers and fillers (9.8/1000 words) are used most frequently, whereas individual lexical words (5.6/1000 words) are much less frequent, and pronoun constructions with tai (1.6/1000 words) are rarer still. Closer analysis revealed that the only statistically significant change between the analysed periods (Soviet, transitory and contemporary) was a decrease of the frequency of non-standard lexical words in the contemporary period compared to the previous ones. The frequency of discourse markers/fillers and pronoun constructions with tai did not change. Regarding the speaker types, the uses of non-standard words decreased in those groups that are within easier reach of prescriptivism – news readers/voice-overs and talk show hosts. Also, to a lesser extent, in the group of experts. Those groups of speakers that are less likely to be subjected to language correction practices (ordinary people) did not seem to change their behaviour: the number of non-standard words in their speech did not decrease, on the contrary, a slight increase has been noticed. These findings confirm the effects of institutionalised prescriptivism. Regarding genres, non-standard words are least frequent in information programmes, which are mostly based on the reading of written texts. Lists of the most frequent non-standard words during the three periods overlap to a great extent, which means that despite prescriptivist practices, the most frequent non-standard words do not disappear from the air.The fifth chapter “Change in the functions of non-standard words: a qualitative analysis” investigates specific communicative situations of the usage of non-standard words and takes into account the media-related and societal contexts, as well as the stylistic and social functions of the corrected lexis. A common trait of the use of non-standard words during all periods, interpreted as the first level of indexicality, is the use of common, everyday vocabulary, most likely without being aware of the “incorrect” status of the chosen forms. Also, non-standard words are used as a part of professional language, in this case the speaker might be aware that he or she is using an ‘incorrect’ word, but chooses to use it nevertheless for convenience or because of its indexical value for professional identity. During all the periods, non-standard words are also used as indices of informal and authentic communication between close acquaintances; this function is performed by all types of the studied non-standard words, particularly old borrowings and frequent fillers.The study identified a few style- and social meaning-related uses of non-standard lexis that explain the choice of the corrected forms instead of the required equivalents. In the Soviet period, some non-standard words were used as a part of Soviet newspeak; old borrowings were used in references to the ideological enemies of Soviet rule, mainly the ones from pre-war Lithuania. In certain cases, these words were employed due to their stylistic value in an intimate and authentic discourse. The late Soviet period saw the first use of non-standard words as markers of informal communication. The use of non-standard words in the transitory period shows some of the functions from the Soviet period, e.g., they are used as an element of newspeak, albeit without the Soviet ideological value, or as expressions of informality. A particular feature of this period is the use of non-standard words as an index of live and authentic speech, which was not allowed during Soviet times, as a means of authentic communication, and the criticism and violation of Soviet taboos. The contemporary period is marked by a huge variety of functions of non-standard words. It brings in a number of new style-related functions of non-standard words: construction of youth-oriented identity and youth-oriented referee design, reference to past times (e.g., by using non-standard words reflecting the Soviet reality), or quoting. Perhaps the most distinctive features of this period are the use of non-standard words in the speech of professional journalists, as well as their use for the purposes of humour and entertainment (for the construction of certain personas), e.g., in language plays and stylisations. These uses can be explained by commercial media requirements, increasing trends of the informalisation of public speech and conversationalisation.The study concluded that the effect of prescriptivism on the use of non-standard words in radio and TV in Lithuania is limited. Firstly, the frequency of non-standard words decreased mainly in those groups of speakers that are subject to the formal, institutionalised power of language gatekeepers (media professionals). Secondly, the data shows a decrease only of those non-standard words that are easier to control by the speakers themselves – lexical words. The frequency of various function words that are more difficult to be aware of when speaking did not decrease. Thirdly, the largest decrease in non-standard lexical forms occurred in those speech situations where a prepared written text is used; this means that prescriptivist requirements have a greater effect when the speakers and the language are controlled, and less effect in spontaneous communication situations. The above-mentioned difference between professional and non-professional speakers demonstrates that speakers are able to control the lexical forms they choose.Analysis of the most frequently used non-standard words during different periods also demonstrates the limits of prescriptivism. The lists of the most frequently used non-standard words during different periods overlap to a great extent, which means that despite prescriptivist efforts, they were not eliminated from being used on air.Finally, the limited success of prescriptivism is demonstrated by the discussed social values of non-standard words, when they are used for various social and stylistic functions not possessed by a ‘correct’ equivalent. The qualitative analysis revealed the particular strength of old borrowings, which are used to create a sincere, friendly speech style, as well as a ludic speaker identity. On the one hand, it can be interpreted as a sign of the ineffectiveness of prescriptivism – if the words are needed, it is likely that they will be further used despite their ‘illegal’ status. On the other hand, when the speakers purposefully (e.g., on account of a particular association, stylistic value) choose a particular language form and are at the same time aware about its “incorrectness”, it is an effect of prescriptivism, only with the opposite outcome.The study is based on the analysis of spoken language on radio and TV, therefore it cannot be used to draw conclusions about the Lithuanian language in general. It is likely that the effect of prescriptivism on written language (because of its more formal style and particularly because of language editing practices) would be stronger. Nevertheless, broadcast media speech constitutes a considerable and important part of language use, thus we can conclude that the impact of prescriptivism on the Lithuanian language does not have far-reaching effects.

Objectives The aim of this study was to understand what influenced people living with dementia and their family carers’ adherence to the home-based component of a Tai Chi exercise intervention. Method Dyads, of people living with dementia and their family carers, who participated in the intervention arm of the Tai Chi for people living with dementia trial, were invited to join weekly Tai Chi classes for 20 weeks and practice at home. Semi-structured dyadic home interviews were conducted on average after 16 weeks of classes. The views of 15 dyads with a range of home practice adherence were sought in semi-structured interviews. The interviews were analysed using an inductive thematic approach. Results Most participants found time to practise Tai Chi at home and practised for 18 hours on average. Amongst the barriers to adherence were participants’ competing commitments and a booklet not sufficiently conveying the Tai Chi movements. Hence, a video or DVD was requested by participants. Facilitators of their adherence to the home-based component of the intervention were their enjoyment of the practice and the development of a habit, which was supported by their commitment to the study and their willingness to benefit from Tai Chi. Conclusion Enjoyment and perceived benefits had a great impact on participants living with dementia and their carers’ adherence to home-based Tai Chi practice. However, difficulties to perceive the Tai Chi movements through images might be hindering sustained participation. Hence, alternative aids such as videos and DVDs should be explored to facilitate adherence.

The balance of oxidative and antioxidant systems is of great importance to the human body. Physical exercise, as one of the ways to improve physical health, seems to modulate this balance. However, different intensities and types of physical exercise have other effects on the treatment of unhealthy people. To understand the impact of exercise training on the oxidative and antioxidant systems of adults with oxidative stress-related disorders, a network meta-analysis was used to compare the mixed effects of different intensities and types of exercise training. This systematic review included all eligible RCTs from PubMed, Medline, Cochrane Library, and CINAHL. Eleven of the studies met the inclusion criteria (at study completion, n = 666 participants). Seven studies reported that the level of MDA decreased significantly after exercise (p &lt; 0.05), and 3 studies reported that the level of SOD increased significantly after exercise (p &lt; 0.05). In conclusion, long-term high-intensity aerobic training and Tai Chi or Yoga can effectively improve oxidative stress in unhealthy people. In addition, different types of diseases on the effect of exercise intervention seems to be other, diabetes and chronic kidney patients using moderate-intensity aerobic training or Tai chi and Yoga effect are better; Moderate-intensity aerobic training had a better impact on OS improvement in patients with irritable bowel syndrome and severe depression. However, more research is needed to determine the effects of different levels and types of physical activity on oxidative stress in unhealthy populations.Systematic Review Registration: PROSPERO identifier: CRD42021242025. https://www.crd.york.ac.uk/prospero/.

PurposeDebt, dividend and investment policy constitutes a company's important financial decisions to determine firm performance. The research emphasizes on the problem of overinvestment, a phenomenon that worsens firm operation. Furthermore, it clarifies the moderation role of debt and dividend policy in mitigating the negative effect of overinvestment on firm performance in the case of Vietnamese listed companies.Design/methodology/approachThe research uses all financial statement of non-financial Vietnamese listed companies on Ho Chi Minh and Hanoi Stock Exchange in the period of 2008–2018. The data are collected from Thomson Reuters Eikon. The final data set is comprised of 669 listed companies. The study measures overinvestment though investment demand function and HP filter. Moreover, the research employs the dynamic model, so it has to apply the SGMM method to deal with the problem of endogeneity caused by the lagged dependent variable.FindingsThe research finds that overinvestment is negatively associated with firm performance. Debt or dividend policy separately can moderate the negative effect of overinvestment on firm performance. However, when these two policies are combined, they lessen the positive interaction impact of each policy due to the substitution between debt and dividend policy.Research limitations/implicationsThe research may have two limitations. Firstly, the research measures overinvestment indirectly through investment demand function and HP filter. These two measures only help identify the sign that companies may have the problem of overinvestment because we cannot determine whether they overinvest or not in reality. Secondly, when using interaction variables, the problem of multicollinearity may be higher, and this may adjust the signs and significance level of variables in the models.Practical implicationsPractically, the research proposes three policy recommendations. Firstly, a company can exploit debt or dividend policy to limit excessive free cash flow in order to constrain the problem of overinvestment. Secondly, a company should enhance its corporate governance to resolve agency problems. Thirdly, the government should make the financial sector more transparent and effective to improve monitoring functions of various parties in the capital market.Social implicationsOverinvestment sometimes can cause social issues. Overinvestment means that companies make ineffective investment. If they continue this situation over a long time, companies may have financial distress or even go bankruptcy. As a result, it will slow down economic growth and increase unemployment in the economy.Originality/valueThe research is supposed to make two great contributions to the existing empirical studies in two aspects. Firstly, it is the first attempt to take into consideration the interaction between overinvestment and financial policies. Secondly, it helps enhance the fundamental stance of the agency theory, which supports the interdependence of debt, dividend and investment policy.

L’autore affronta il tema della allocazione delle risorse sanitarie adottando una prospettiva etico-politica di tipo solidale. In particolare, viene messo in risalto come la sanità pubblica italiana comporti una spesa a carico del cittadino sempre maggiore, soprattutto per determinate categorie di soggetti quali i malati cronici non autosufficienti. Una indagine condotta per conto dell’OMS rileva infatti che in Italia i malati affetti da patologie più gravi ricevono in proporzione meno cure dei pazienti con patologie di grado lieve/moderato. Si tratta, dunque, del cosiddetto “effetto Matteo” - mutuato dalla espressione evangelica - secondo cui “a chi ha sarà dato e a chi non ha sarà tolto anche quello che ha”. Traslato alla realtà sanitaria ciò esita nel deprecabile superamento del criterio di severità clinica quale caposaldo dell’assistenza socio-sanitaria a vantaggio di criteri economicistici rappresentati da un uso improprio del sistema di remunerazione delle prestazioni sanitarie secondo DRG, che penalizza il produttore il quale sfori il limite di budget fissato dalle autorità sanitarie, magari a motivo di una maggiore attenzione all’assistenza dei malati cronici e/o disabili. Va peraltro considerato che la medicina attuale sconta altri limiti oltre a quelli relativi alle risorse, in particolare il limite rappresentato dalla finitezza umana, di cui occorrerebbe prendere serenamente atto. L'articolo considera peraltro in modo analitico alcuni strumenti utilizzati per la valutazione dell’efficacia e dell’efficienza degli interventi sanitari (QALYs, EQALYs, UVG, UVH, ROSES), mettendone in risalto punti di forza e criticità. In definitiva, occorre riferirsi sempre ad un criterio solidaristico, adottando peraltro una rigorosa logica di cura ed assistenza personalizzate, il che consentirebbe un utilizzo ottimale di risorse. ---------- The Author faces the issue of the allocation of the health resources adopting a solidarity ethical perspective. Particularly, it is underlined that Italian health care system involve an expense more and more in charge of the citizen, above all for subjects with chronic pathologies. In fact, a survey by WHO highlights that in Italy the sick affected by serious pathologies (disability, mental disease) receive less care than patients with slight/moderate diseases: therefore, the so called “Matthew effect”. In this perspective, the “clinical severity” criterion is overcome by the economical one, the perspective payment system of health care services is utilized in improper way and penalizes the health maintenance organization that dedicate great attention to chronic sick. On the other hand, the medicine has indubitable limits: resources, but above all, the probabilistic nature of outcomes and the finite nature of man. The article considers some tools used for the evaluation of effectiveness and the efficiency of health interventions (QALYs, EQALYs, UVG, UVH, ROSES), bringing out strengths and weaknesses. Finally, it is always necessary to refer to a solidarity criterion, adopting a rigorous logics of care and personalized care: this approach would allow a better use of resources.

Abstract Study question What are the stress scale and coping strategies of patients who were unable to start/continue an IVF cycle due to COVID–19 interruption on ART treatments? Summary answer Stress scale was associated to specific coping strategies and was higher for women, patients in first IVF treatment, had compromised income and younger than 38yo. What is known already In March 2020, due to the COVID–19 outbreak caused by the SARS-CoV–2 virus, human reproduction societies, have recommended discontinuation of reproductive care, except for the most urgent cases. After few months, the treatments were resumed following proper safety guidelines. Infertility diagnostic and treatments are severe stressors, causing anxiety, depression and general emotional distress. The disruption of treatments and the pandemic uncertain scenario in all life aspects, certainly have a great impact on mental health of ART patients. There is an urge need to assess the level of stress and coping strategies in this population to offer suitable support and care. Study design, size, duration Prospective, Brazilian multicentric study (6 clinics of ART located in São Paulo, Campinas, Belo Horizonte and Brasilia), with the application of an anonymous online survey of stress scale and 14 coping strategies to 1500 patients (male and female) that had their treatments interrupted or unable to start during the months of March, April and May 2020. The online survey was sent during the months of August/September and responses were collected until early October/2020. Participants/materials, setting, methods The stress scale level was assessed using the Perceived Stress Scale protocol (PSS), and coping strategies using the Brief COPE scale protocol. Social-demographic variables (gender, age, city of residence, marital status, time of infertility, previous IVF treatments and financial impact) were included in the survey. Marginal statistical analyses were performed accordingly (t test, Mann-Whitney, Kruskal-Wallis, chi-square test) and a linear regression model was carried out to calculate the effect of COPE strategies on stress scale. Main results and the role of chance Survey’s response rate was 44.4% (n = 666). The majority were women (83.3%), married (93.2%, mean of 9,41±4,76 years), deal with infertility for 2–5 years (51.5%), had done a previous IVF treatment (61.4%, mean of 2,33 treatments) and had a work activity (83.9%). Almost 40% had their income compromised by the pandemic. Mean age was 38.47±4.99 years (≥38 yo = 59%). Stress scale was higher for women (p &lt; 0.0001), patients that were in their first IVF treatment (p = 0.011), had their income compromised (p = 0.001) and were younger than 38yo (p &lt; 0.0001). The most frequent coping strategies (score 5–8) were planning (87.7%), active coping (83%), positive reframing (72.1%) and religion (71.7%). Women used more emotional support, religion, venting (all p &lt; 0.0001) and self-distraction (p = 0.002) as coping strategies than men. Younger patients (&lt;38yo) reported more use of substances (p = 0.002) and self-distraction (p = 0.001) than older patients. Lower income was associated with denial (p = 0.002) and less use of religion (p &lt; 0.0001) and patients that were about to start their 1st treatment used more venting (p &lt; 0.0001) and denial (p = 0.003) than recurrent patients. The linear regression analysis showed that higher stress was associated to planning, religion, self-blame, venting, self-distraction and behavioral disengagement and lower stress scale to active coping, emotional support, positive reframing and acceptance. Limitations, reasons for caution This study was performed in Brazil, one of the most affected countries by the COVID–19 outbreak, which may limit the generalizability of the findings. Another limitation was the impossibility to compare the stress scale and coping strategies findings in this population prior to the pandemic. Wider implications of the findings: Being a woman and have a compromised income were expected stressor factors. Surprisingly, first IVF attempt and younger patients showed higher stress scale and the use of psychological defense mechanisms, such as the use of substances, denial and self-distraction. Continuous emotional support should be offer for all ART patients. Trial registration number Not applicable

IntroductionCan a person’s tastes in art, music, literature, cinema, sport, humour or other fields be changed through online activity? This article explores that question by comparing recent research findings in the areas of neuroplasticity and flow. Neuroplasticity, also known as brain plasticity, is the idea that the human brain can change its structure and function through thought and activity, even into old age (Doidge). The second concept—flow—comes from the field of psychology, and refers to a deeply satisfying state of focused attention that people sometimes experience while engaging in an enjoyable activity such as browsing the Web (Csikszentmihalyi, Flow). Research into the experiences of web users, conducted from these two different perspectives, reveal interesting connections to the acquisition of taste and opportunities for further investigation. Neuroplasticity The term neuroplasticity comes from the words neuron and plastic. Neurons are the nerve cells in our brains and nervous systems. Plastic, in this context, means flexibility or malleability. Neuroplasticity has replaced the formerly-held belief that the brain is a physiologically static organ, hard-wired like a machine (Kolb, Gibb and Robinson). For much of the last century, scientists believed that adult brains, unlike those of children, could not produce new neurons or build new pathways or connections between neurons. According to this view, any brain function that was lost through damage was irretrievable. Today, research into neuroplasticity has proven that this is not the case. In the late 1960s and 1970s pioneering scientists such as Paul Bach-y-Rita demonstrated that brains change their structure with different activities they perform (Kercel). When certain parts fail, other parts can sometimes take over. Subsequent research by many scientists has validated this once-controversial idea, leading to practical benefits such as the restoration of limb function in stroke victims, and improved cognition and perception in people with learning disabilities (Nowak et al.). Merzenich, for example, has demonstrated how a brain’s processing areas, called brain maps, change in response to what people do over the course of their lives. Different brain maps exist for different activities and functions, including sensory perception, motor skills and higher mental activities. Brain maps are governed by competition for mental resources and the principle of “use it or lose it.” If a person stops exercising particular mental skills, such as speaking Spanish or playing piano, then the brain map space for those skills is handed over to skills that they practise instead. Brain maps are also governed by a principle that is summarised by the expression, “neurons that fire together wire together” (Doidge 63). Neurons in brain maps develop stronger connections to each other when they are activated at the same moment in time. Consequently people are able to form new maps by developing new neural connections. Acquiring Tastes Doidge has illustrated the role that neuroplasticity plays in acquiring new tastes by explaining how habitual viewing of online pornography can shape sexual tastes (102). In the mid- to late-1990s, Doidge (a psychiatrist and psychoanalyst) treated several men who had lost interest in their sexual partners as a consequence of their addiction to online pornography. Doidge explains their change of sexual taste in terms of neuroplasticity, noting that “pornography, delivered by high-speed Internet connections, satisfies every one of the prerequisites for neuroplastic change” (102). The sexual excitement of viewing pornography releases a chemical neurotransmitter named dopamine that activates the brain’s pleasure centres. Since “neurons that fire together wire together”, the repeated viewing of pornography effectively wires the pornographic images into the pleasure centres of the brain with the focused attention required for neuroplastic change. In other words, habitual viewers of pornography develop new brain maps based on the photos and videos they see. And since the brain operates on a “use it or lose it” principle, they long to keep those new maps activated. Consequently, pornography has an addictive power. Like all addicts, the men who Doidge treated developed a tolerance to the photos and videos they observed and sought out progressively higher levels of stimulation for satisfaction. Doidge explains the result: The content of what they found exciting changed as the Web sites introduced themes and scripts that altered their brains without their awareness. Because plasticity is competitive, the brain maps for new, exciting images increased at the expense of what had previously attracted them—the reason, I believe, they began to find their girlfriends less of a turn-on. (109) If the habitual viewing of online pornography can change sexual tastes, what other tastes can be changed through online activity? Art? Music? Literature? Cinema? Sport? Humour? One avenue for investigating this question is to consider existing research into the flow experiences of web users. The term flow refers to a deeply satisfying state of focused attention that was first identified by psychologist Mihaly Csikszentmihalyi (Beyond Boredom) in his studies of optimal experiences. According to Csikszentmihalyi, people in flow “are so involved in an activity that nothing else seems to matter; the experience itself is so enjoyable that people will do it even at great cost, for the sheer sake of doing it” (Flow 4). Flow experiences are characterised by some common elements, which include a balance between the challenges of an activity and the skills required to meet those challenges; clear goals and feedback; concentration on the task at hand; a sense of control; a merging of action and awareness; a loss of self-consciousness; a distorted sense of time; and the autotelic experience. The term autotelic refers to an activity that is done, not with the expectation of some future benefit, but simply because the doing itself is the reward. Whenever people reflect on their flow experiences, they mention some, and often all, of these characteristics. Support for Csikszentmihalyi’s characterisation of flow can be found in studies of many diverse activities, such as playing computer games (Chen) and participating in sport (Jackson), to mention just two examples. The activities that people engage in to experience flow vary enormously, but they describe how it feels in almost identical terms. Pace has developed a grounded theory of the flow experiences of web users engaged in content-seeking activities including directed searching and exploratory browsing. The term grounded in this instance refers to the fact that the theory was developed using the Grounded Theory research method, and its explanations are grounded in the study’s data rather than deduced from research literature (Charmaz). A review of that theory reveals many similarities between the flow experiences of web users engaged in content-seeking activities and the experiences of habitual viewers of online pornography described by Doidge. The following sections will consider several of those similarities. Focused Attention Focused attention is essential for long-term neuroplastic change. Goleman notes that “when practice occurs while we are focusing elsewhere, the brain does not rewire the relevant circuitry for that particular routine” (164). In a series of brain mapping experiments with monkeys, Merzenich discovered that “lasting changes occurred only when his monkeys paid close attention” (Doidge 68). When the animals performed tasks without paying close attention, their brain maps changed, but the changes did not last. Focused attention also plays a central role in the flow experiences of web users. The higher-than-average challenges associated with flow activities require a complete focusing of attention on the task at hand, or as Csikszentmihalyi puts it, “a centering of attention on a limited stimulus field” (Beyond Boredom 40). An important by-product of this fact is that flow leaves no room in one’s consciousness for irrelevant thoughts, worries or distractions (Csikszentmihalyi, Flow 58). People who experience flow frequently report that, while it lasts, they are able to forget about the unpleasant aspects of life. Consider the following comment from a 42-year-old male’s recollection of experiencing flow while using the Web: “It’s a total concentration experience. You’re so interested in doing what it is you’re doing that nothing’s interrupting you.” In everyday life, one’s concentration is rarely so intense that all preoccupations disappear from consciousness, but that is precisely what happens in a flow experience. All of the troubling thoughts that normally occupy the mind are temporarily suspended while the pressing demands of the flow activity consume one’s attention. Let’s now consider a second similarity between the flow experiences of web users and the taste-changing experiences of habitual viewers of online pornography. Enjoyment The pleasure experienced by the pornography addicts treated by Doidge played an important role in the alteration of their brain maps and sexual tastes. Since “neurons that fire together wire together”, the repeated viewing of pornographic photos and videos wired those images into the pleasure centres of their brains with the focused attention required for neuroplastic change. Web users in flow also experience enjoyment, but possibly a different kind of enjoyment to the pleasure described by Doidge. Seligman and Csikszentmihalyi make the following distinction between pleasure and enjoyment: Pleasure is the good feeling that comes from satisfying homeostatic needs such as hunger, sex, and bodily comfort. Enjoyment, on the other hand, refers to the good feelings people experience when they break through the limits of homeostasis—when they do something that stretches them beyond what they were—in an athletic event, an artistic performance, a good deed, a stimulating conversation. (12) The enjoyment experienced by people in flow is sometimes described as “the autotelic experience.” According to Csikszentmihalyi, an autotelic experience is “a self-contained activity, one that is done not with the expectation of some future benefit, but simply because the doing itself is the reward” (Flow 67). Because autotelic experiences are so satisfying, they create a strong desire to repeat the activity that produced the experience. Consider the following comment from a web user about the reasons he enjoys online content-seeking activities that have led to flow: It’s like going to somewhere new. You’re always learning something. You’re always finding something. And you don’t know what it is you’re going to find. There’s so much out there that you’ll go there one day and then you’ll come back, and you’ll actually end up on a different path and finding something different. So it’s investigation of the unknown really. This comment, like many web users’ recollections of their flow experiences, points to a relationship between enjoyment and discovery. This connection is also evident in flow experiences that occur during other kinds of activities. For example, Csikszentmihalyi suggests that “the reason we enjoy a particular activity is not because such pleasure has been previously programmed in our nervous system, but because of something discovered as a result of interaction” (The Evolving Self 189). He illustrates this point with the example of a person who is at first indifferent to or bored by a particular activity, such as listening to classical music. When opportunities for action in the context of the activity become clearer, or when the individual’s skills improve, the activity may start to be interesting and finally gratifying. For example, if a person begins to understand the design underlying a symphony he or she might begin to enjoy the act of listening. This example hints at how discovery, enjoyment and other rewards of flow may engender change in a person’s taste. Let’s now consider a third similarity between the two areas of research. Compulsive Behaviour One consequence of flow experiences being so enjoyable is that they create a strong desire to repeat whatever helped to make them happen. If a person experiences flow while browsing online for new music, for example, he or she will probably want to repeat that activity to enjoy the experience again. Consider the following comment from a 28-year-old female web user who recalled experiencing flow intermittently over a period of three days: “I did go to bed—really late. And then as soon as I got up in the morning I was zoom—straight back on there […] I guess it’s a bit like a gambling addiction.” This study informant’s use of the term addiction highlights another similarity between the flow experiences of web users and habitual viewing of online pornography. Flow experiences can, in a very small percentage of cases, encourage compulsive behaviour and possibly addiction. A study by Khang, Kim and Kim found that “experiences of the flow state significantly influenced media addiction” across three media forms: the Internet, mobile phones and video games (2423). Examples of problems associated with excessive Internet use include sleep deprivation, poor eating and exercise habits, conflict with family members, and neglect of academic, interpersonal, financial and, occupational responsibilities (Douglas et al). Some heavy Internet users report feelings of moodiness and anxiety while they are offline, along with an intense desire to log in. Doidge states that “the addictiveness of Internet pornography is not a metaphor” (106), but many researchers are reluctant to apply the term addiction to heavy Internet use. Internet addiction first came to the attention of the research community in the mid-1990s when Young conceptualised it as an impulse-control disorder and proposed a set of diagnostic criteria based on the diagnostic criteria for pathological gambling in the Diagnostic and Statistical Manual of Mental Disorders. However, after more than fifteen years of research on this subject, there is still no agreement on a definition or diagnostic criteria for Internet addiction. Some researchers argue that Internet addiction is not a true addiction and may be no more than a symptom of other existing disorders such as anxiety or depression (Weinstein and Lejoyeux). Regardless of this controversy, the potential for compulsive behaviour is another clear similarity between the flow experiences of web users and the neuroplastic change caused by habitual viewing of online pornography. One more similarity will be considered. Sidetracks In Pace’s study of the flow experiences of web users, informants reported engaging in two general types of content-seeking behaviour: (1) a directed searching mode in which one is motivated to find a particular piece of content such as the answer to a question or a specific music video; and (2) an exploratory browsing mode that is characterised by diffuse motives such as passing time or seeking stimulation. Directed searching and exploratory browsing are not dichotomous forms of navigation behaviour. On the contrary, they are closely interrelated. Web users move back and forth between the two modes, often many times within the same session. Just as web users can change from one navigation mode to another, they can also get sidetracked from one topic to another. For instance, it is reportedly quite common for a web user engaged in a content-seeking activity to decide to pursue a different goal because his or her curiosity is aroused by interesting content or links that are not directly relevant to the task at hand. Consider the following comment from a 21-year-old female web user whose desire to find contact details for a local Tai Chi group disappeared when a link to the Sportsgirl web site attracted her attention: I think I typed in “sports” […] I was actually looking for a place to do Tai Chi and that sort of thing. So I was looking for a sport. And it ended up coming up with the Sportsgirl web site. And I ended up looking at clothes all afternoon. So that was kind of cool. Sidetracks are a common feature of the flow experiences of web users. They are also a prominent feature of the description that Doidge provided of the pornography addicts’ neuroplastic change (109). The content of what the men found exciting changed as the web sites they viewed introduced “themes and scripts” or sidetracks that altered their brain maps. “Without being fully aware of what they were looking for, they scanned hundreds of images and scenarios until they hit upon an image or sexual script that touched some buried theme that really excited them”, Doidge notes (110). Conclusion Can a person’s tastes in art, music, literature, cinema, sport, humour or some other field be changed through online activity, just as sexual tastes can? This article alone cannot conclusively answer that question, but significant similarities between the flow experiences of web users and the neuroplastic change experienced by habitual viewers of online pornography suggest that flow theory could be a fruitful line of investigation. Can the flow experiences of web users lead to changes in taste, just as the neuroplastic change caused by habitual viewing of online pornography can lead to changes in sexual taste? What is the relationship between flow and neuroplastic change? Is the Internet the most appropriate environment for exploring these questions about taste, or do offline flow activities provide insights that have been neglected? These are some of the unanswered questions arising from this discussion that require further investigation. Advances in the field of neuroplasticity have been described as some of “the most extraordinary discoveries of the twentieth century” (Doidge xv). These advances provide an opportunity to revisit related theories and to enhance our understanding of phenomena such as flow and taste. References Charmaz, Kathy. Constructing Grounded Theory: A Practical Guide Through Qualitative Analysis. Thousand Oaks, California: Sage Publications, 2006. Chen, Jenova. “Flow in Games (and Everything Else).” Communications of the ACM 50.4 (2007): 31–34. Csikszentmihalyi, Mihaly. Beyond Boredom and Anxiety: The Experience of Play in Work and Games. San Francisco: Jossey-Bass Publishers, 1975. Csikszentmihalyi, Mihaly. The Evolving Self: A Psychology for the Third Millennium. New York: HarperPerennial, 1993. Csikszentmihalyi, Mihaly. Flow: The Psychology of Optimal Experience. New York: HarperPerennial, 1990. Doidge, Norman. The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science. Melbourne: Scribe Publications, 2010. Douglas, Alecia C., Juline E. Mills, Mamadou Niang, Svetlana Stepchenkova, Sookeun Byun, Celestino Ruffini, Seul Ki Lee, Jihad Loutfi, Jung-Kook Lee, Mikhail Atallah, and Marina Blanton. “Internet Addiction: Meta-Synthesis of Qualitative Research for the Decade 1996-2006.” Computers in Human Behavior 24 (2008): 3027–3044. Goleman, Daniel. Focus: The Hidden Driver of Excellence. New York: HarperCollins, 2013. Jackson, Susan. “Toward a Conceptual Understanding of the Flow Experience in Elite Athletes.” Research Quarterly for Exercise and Sport 67.1 (1996): 76–90. Khang, Hyoungkoo, Jung Kyu Kim, and Yeojin Kim. “Self-Traits and Motivations as Antecedents of Digital Media Flow and Addiction: The Internet, Mobile Phones, and Video Games.” Computers in Human Behavior 29 (2013): 2416–2424. Kercel, Stephen W. “Editorial: The Wide-Ranging Impact of the Work of Paul Bach-y-Rita.” Journal of Integrative Neuroscience 4.4 (2005): 403–406. Kolb, Bryan, Robbin Gibb, and Terry E. Robinson. “Brain Plasticity and Behavior.” Current Directions in Psychological Science 12.1 (2003): 1–5. Merzenich, Michael. Soft-Wired: How the New Science of Brain Plasticity Can Change Your Life. San Francisco: Parnassus Publishing, 2013. Nowak, Dennis A., Kathrin Bösl, Jitka Podubeckà, and James R. Carey. “Noninvasive Brain Stimulation and Motor Recovery After Stroke.” Restorative Neurology and Neuroscience 28 (2010): 531–544. Pace, Steven. “A Grounded Theory of the Flow Experiences of Web Users.” International Journal of Human-Computer Studies 60.3 (2004): 327–363. Seligman, Martin E. P., and Mihaly Csikszentmihalyi. “Positive Psychology: An Introduction.” American Psychologist 55.1 (2000): 5–14. Weinstein, Aviv, and Michel Lejoyeux. “Internet Addiction or Excessive Internet Use.” The American Journal of Drug and Alcohol Abuse 36 (2010): 277–283. Young, Kimberly S. Caught in the Net: How to Recognize the Signs of Internet Addiction—And a Winning Strategy for Recovery. New York: John Wiley & Sons, 1998.

Abstract Study question Is there any difference in the time to obtain euploid embryos from poor prognosis patients who performed two conventional cycles versus double stimulation (DuoStim) in the same cycle? Summary answer DuoStim showed similar ovarian response and in vitro fertilization (IVF) laboratory outcomes while shortening the time to obtain an euploid embryo in poor prognosis patients. What is known already Several waves of cyclic development of antral follicles within the same menstrual cycle have been demonstrated. Likewise, it has been shown that oocytes obtained from luteal phase ovarian stimulation (OS) have similar competence than those obtained in the follicular phase OS. Often, some patients require sequential OS in order to obtain more oocytes and increase their chances to reach embryo transfer. Thus, the DuoStim strategy could be an attractive alternative to reduce the time-to-pregnancy. However, prospective data and randomized trials that validate this strategy are lacking. Study design, size, duration We conducted a prospective, randomized controlled trial at our institution from[MCM1] [JAGV2] January 2017 to December 2020. A total of 80 poor prognosis patients aged over 38 years undergoing PGT-A were enrolled in two groups: 39 patients did two OS in consecutive cycles (control) whereas 41 women underwent two OS in the same menstrual cycle (DuoStim). Participants/materials, setting, methods Poor prognosis was defined as suboptimal responders. The primary outcome was the time needed to obtain an euploid embryo. The secondary outcomes were duration of stimulation, dose of gonadotropins, oocyte maturity rate, fertilization and blastocyst formation rates. Variables were expressed as mean ± standard deviation. Statistical analyses was performed by ANOVA and Chi-square tests, as appropriate. Differences were considered significant when p-value &lt; 0.05. Main results and the role of chance The patients’ baseline characteristics were similar between groups. We did not find any difference in the mean days of stimulation between the control and the DuoStim group (21.3 ± 1.6 vs. 23 ± 1.4, p = 0.105), nor in the amount of gonadotropin required (4005 ± 450 vs. 4245 ± 430, p = 0.43), number of MII oocyte (8.7 ± 1.8 vs. 6.8 ± 1.7, p = 0.159), blastocyst rate (51.4% vs. 34.8%, p = 0.113) and the number of euploid embryos (0.8 ± 0.4 vs. 0.6 ± 0.4, p = 0.45). However, there was a significant difference in the average number of days until reaching an euploid blastocyst, favoring the DuoStim group (44.1 ± 2 vs. 23.3 ± 2.8, p &lt; 0.001). Comparing the follicular versus the luteal phase within the DuoStim group, the only difference detected concerns to the mean days of stimulation (10.3 ± 0.8 vs. 12.7 ± 0.9, p &lt; 0.001). We also observed a trend towards a higher fertilization (38.1% vs. 61.8%, p = 0.02) and blastulation rate (23% vs. 53%, p = 0.03) in the luteal phase of the DuoStim cycle. Limitations, reasons for caution The major limitation is related to the limited sample size, as it limits our power analysis (70%). On the other hand, it is one of the first randomized prospective pilot trial that compared the efficiency of performing two consecutive ovarian stimulation in different menstrual cycles with the DuoStim strategy. Wider implications of the findings This study clearly showed that the DuoStim protocol is not inferior to the conventional stimulation in terms of ovarian response and laboratory outcomes. Moreover, the DuoStim reduces the time to obtain an euploid embryo in poor prognosis patients, which is of great clinical utility. Trial registration number NCT03291821