Artículos de revistas sobre el tema "Greater Lomé"
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Blakime, Têtou-Houyo, Kossi Adjonou, Kossi Komi, Atsu K. Dogbeda Hlovor, Kodjovi Senanou Gbafa, Jean-Bosco Benewinde Zoungrana, Botolisam Polorigni y Kouami Kokou. "Dynamics of Built-Up Areas and Challenges of Planning and Development of Urban Zone of Greater Lomé in Togo, West Africa". Land 13, n.º 1 (11 de enero de 2024): 84. http://dx.doi.org/10.3390/land13010084.
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The expansion of African cities leads to the occupation of peripheral urban areas without respecting planning rules. The Greater Lomé (Togo) is no exception to this phenomenon of high-speed horizontal spreading, which causes recurrent flooding. The objective of this research is to understand the spatio-temporal changes in the dynamics of built-up areas in Greater Lomé. The methodology used is based on the analysis of Landsat images from the years 2007, 2012, 2016, and 2020 coupled with direct field observations and a literature review. The results showed an increase in residential areas to the detriment of the other land use/cover types. Estimated at 15,481 ha in 2007, the built-up area reached 35,521 ha in 2020, an increase of 33% to the detriment of vegetation and cultivation areas. This increase was marked by constructions in the floodplain of the Zio River. The field surveys revealed an increase in the density of most of the agglomerations. From 1863 ha in 2007, they increased to 14,485 ha in 2020, an increase of 12,622 ha or approximately 33%. These results indicate that attention needs to be paid to both the planning and control of the development of spaces in the outlying areas of Greater Lomé.
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Atator, Lawson Tevi, Kamou Hodabalo y Akpavi Ben Semihinva. "Methane Emissions from Landfills Sites and Their Contribution to Global Climate Change in the Greater Lomé Area of Togo (West Africa)". Environment and Pollution 13, n.º 1 (12 de enero de 2024): 23. http://dx.doi.org/10.5539/ep.v13n1p23.
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This study was carried out in the city of Lomé in Togo. The study looked at the contribution of illegal waste landfills to climate change. The focus was on the quantities of methane released by uncontrolled landfills. In order to achieve the objectives, set by this study, the quantity of methane was recorded at twenty (20) landfills in thirteen (13) localities using microsensors over a period of thirty-two (32) days. The measurements were taken at the landfills with the measuring device stationed in the middle of the landfill at a height of 25 cm above the waste. The data collected was processed and a probability diagram was drawn up, making it possible to assess whether or not a set of data follows a given distribution such as the normal or Weibull distribution. Similarly, the contribution of each of the landfills to climate change was determined. During the measurement period, it was found that the TOGBLEKOPE 2 (6.338 g/m3 ± 4.881) with a contribution of 133.09; AMOUTIEVE (5.565 g/m3 ± 2.889) with a contribution of 116.86; ADETIKOPE GUERINKA (5.56 g/m3 ± 2.123) with a contribution of 116.76; GBOSSIME (5.323 g/m3 ± 4.442) with a contribution of 111.78; HOUNBI (4.702 g/m3 ± 3.59) with a contribution of 98.742; ADETIKOPE KPETAVE (4.363 g/m3 ± 2.841) with a contribution of 91.62 and NYEKONAKPOE 2 (4.017 g/m3 ± 3.067) with a contribution of 84.357; release more methane into the atmosphere. This shows the contribution of landfill sites in the fight against climate change.
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Prata, Ndola, Natalie Morris, Komlan Kwassi Agbovi y Orlando Hernandez. "Does time matter? cross–sectional evaluation of mhealth program enrollment duration on healthy behaviors among key populations in Lomé". MOJ Public Health 8, n.º 5 (19 de septiembre de 2019): 172–80. http://dx.doi.org/10.15406/mojph.2019.08.00304.
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Context: Key populations (KP) in Togo, including men who have sex with men and female sex workers, experience disproportionately high rates of HIV prevalence. In response to this situation, USAID/West Africa and FHI360 established the PACTE–VIH regional HIV/AIDS project, which utilized mobile health (mHealth) to send reminders to enrolled participants on ways to reduce the risk of HIV infection. While mHealth programs are known to be effective in improving HIV–related health behavior outcomes, the role of length of time enrolled in a mHealth program is not well understood. Methods: To assess whether there was a relationship between time enrolled in the PACTE–VIH mHealth program and adoption of HIV prevention behavior, we use data from an operations research study conducted in Lomé, Togo, in 2016 with 1005 KP and employ logistic regression analysis. Results: The odds of adopting prevention behaviors were higher with each additional month enrolled in the program (OR: 1.62; 95% CI 1.19–2.20). Fully adjusted (age and marital status) logistic regression models demonstrated no significant difference in odds of adopting prevention behavior between enrollment times of less than six months and any category greater than six months. Conclusion: Time does matter for adoption of HIV prevention behaviors. However, more studies are needed to better understand what length of time enrolled in a program truly affects behavioral outcomes.
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A., Amadou, Sonhaye L., Douaguibe B., Tchaou M., Agbangba KA., Watara G., Adjenou V. y N’dakena K. "Echographie Doppler Arterielle Testiculaire Dans L’infertilite Masculine A Lome". European Scientific Journal, ESJ 13, n.º 6 (28 de febrero de 2017): 449. http://dx.doi.org/10.19044/esj.2017.v13n6p449.
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Objective: Determine the relationship between the testicular arterial resistance index (IR) and spermatogenesis. Material and method: prospective analytical study over a period of 12 months at CHU campus and National Institute of Hygiene of Lomé. The parameters studied were anomalies of sperm count, sperm volume, testis volume, and resistance index (RI). The study of the correlation between our variables was done using the Chi square test (χ2). Results: The mean age of men was 36.26 years. Sperm volume was normal in 73% men and abnormal in 27% men. 65% had normal sperm counts, and 35% had abnormal sperm counts. The normal testicular volume was found in 42% men and 58% had an abnormal testicular volume (hypotrophic testis). 51% men had the pathological RI while 49% had a normal RI. There was no statistically significant relationship between testicular volume and sperm count. Also, no statistically significant relationship between RI and testicular volume. But, there was a statistically significant correlation between RI and sperm count. No statistically significant difference between RI and sperm volume. Conclusion: RI can be used with sperm analysis and hormonal studies as part of the clinical evaluation of infertile men. An intratesticular RI greater than 0.6 is associated with decreased total motile sperm.
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PIO, Machihude, Abalo Mario BAKAI, Bénédict SOUHO, Edabi OTOYI, Kpatekana SIMLAWO, Borgotia D. ATTA, Tchaa TCHEROU et al. "Abdominal Aortic Aneurysms: Epidemiological, Clinical and Echographic Aspects in The Health Structures of Lomé and At The Kara University Hospital (TOGO)". Journal Of Hypertension And Cardiology 3, n.º 3 (10 de enero de 2023): 8–17. http://dx.doi.org/10.14302/issn.2329-9487.jhc-22-4362.
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Objective To describe the epidemiological, clinical and arterial Doppler ultrasound aspects of abdominal aortic aneurysm (AAA). Material and methods This is a prospective study with descriptive and analytical aims carried out from January 2019 to March 2022 (3 years) at the cardiovascular exploration center (CEC) "Saint-Esprit" of the association of the people's doctors for the research on cardiovascular diseases (AMP-MCV), at the clinic "Le Printemps" and at the University Hospital of Kara. All patients who underwent arterial Doppler ultrasound of the lower limbs for any reason in these centers during the study period were included. Ultrasound scans were performed or confirmed by a physician with a diploma specializing in vascular Doppler ultrasound. Results We retained 32 Doppler ultrasound scans out of 739 performed for AAA with a frequency of 4.38%. The mean age was 73.5± 9.07 years. The sex ratio M/F was 1.4. The cardiovascular medical history (84.38%) found was: hypertension (33.33%), diabetes (18.52%), dyslipidemia (33.33%) and a combination of diabetes and hypertension (14.81%). The circumstances of discovery were: downstream MI ischemia (72%), incidental finding on abdominal ultrasound (15.63%) and De bakey sign (6.25%). The location of the aneurysms was subrenal (84.4%), suprarenal (9.4%) and both (6.2%). AAAs were fusiform (71.9%) and saccular (28.1%). The size of the aneurysms was greater than 5 cm in 78.17% of patients. High blood pressure increases the probability of the occurrence of subrenal AAA while dyslipidemia increases the occurrence of fusiform AAA. Diabetes increases the probability of occurrence of AAA larger than 7cm. AAAs were thrombosed in 75% of patients. There were extensions of the aneurysms to the iliac arteries in 70.59%. Downstream embolic complications represented 46.88%, in the form of occlusions and tight stenoses. Spontaneous mortality was 81.24%. Conclusion Arterial Doppler ultrasonography is a very important tool in the screening, positive and lesion diagnosis of AAA. The risk factors for AAA are: age over 60 years, male gender, hypertension, diabetes and dyslipidemia. Early detection remains essential, because the spontaneous prognosis is poor.
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Traoré, Fousseyni, Francis Eshun, Boubacar Togo, Jean Jacques Atteby Yao y Mbuli Robert Lukamba. "Neuroblastoma in Africa: A Survey by the Franco-African Pediatric Oncology Group". Journal of Global Oncology 2, n.º 4 (agosto de 2016): 169–73. http://dx.doi.org/10.1200/jgo.2015.001214.
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Purpose Neuroblastoma is a sympathoadrenal lineage neural crest–derived tumor. It is the third most common childhood malignancy in the Western world. Studies from the United States show that black patients with neuroblastoma have a greater proportion of high-risk neuroblastoma with poorer prognosis compared with white patients. In Africa, there are few published data on the epidemiology and management of neuroblastoma. The primary aim of this study was to assess the diagnostic and therapeutic resources available for the management of neuroblastoma within the Franco-African Pediatric Oncology Group (GFAOP). Methods A survey was conducted in the pediatric oncology centers of the GFAOP. Participating GFAOP centers were Abidjan, Algiers, Bamako, Dakar, Lubumbashi, Lomé, Ouagadougou, Rabat, Tananarive Antananarivo, and Tunis. Questionnaires were sent out by e-mail to the principal investigators at each participating GFAOP center in December 2013. Results Ten (62%) of 16 GFAOP centers responded to the questionnaire. Neuroblastoma represented only 3% to 5% of childhood cancers in the sub-Saharan African centers, with the exception of Antananarivo, where it represented 7.5%. In contrast, in the northern African centers of Tunis, Rabat, and Algiers, neuroblastoma accounted for 30%,10%, and 7% of childhood cancer, respectively. At initial diagnosis, 50% to 80% of patients had metastatic neuroblastoma in eight of 10 centers. Conclusion Based on this survey, neuroblastoma seems to be less common in sub-Saharan Africa. The proportion of patients with metastatic neuroblastoma seems to be higher than reported in Western countries.
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Laakso, Liisa. "The Clinton Administration and Africa: A View from Helsinki, Finland". Issue: A Journal of Opinion 26, n.º 2 (1998): 52–57. http://dx.doi.org/10.1017/s0047160700502959.
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Africa occupies a special position in the foreign policies of the Nordic countries of Denmark, Finland, Iceland, Norway, and Sweden. In spite of their limited capacities, lack of colonial ties with Africa, or any significant economic interests in Africa, the Nordic countries have attained a relatively high profile, especially in Southern Africa. After Finland and Sweden joined the European Union (EU) in 1995, Africa assumed an even greater level of foreign policy significance for the Nordic countries. Most notable in this regard is Finland’s assumption in 1999 of the EU presidency, a position that makes Finland responsible for the negotiations over the continuation of the EU’s Lomé Convention with 71 countries of Africa, the Caribbean, and the Pacific. It is in this context that this article assesses Nordic perceptions of the Clinton administration’s foreign policy toward Africa. It is important to note, however, that there is no one monolithic “Nordic perspective.” The opinions and approaches documented in policy papers or informal statements by individual civil servants following African affairs can widely vary. People working with development cooperation, for example, tend to be more recipient-oriented than those looking at Africa from a more general foreign policy point of view. The tradition of outspoken human rights policy still differentiates Norwegian and Swedish approaches from the cautious policy of Finland. Yet behind these different tones, one can distinguish common premises stemming from the many similarities of the Nordic countries and their conscious efforts to generate coherent, coordinated foreign policies toward Africa.
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Akinocho, Herve, Ken Brackstone, Nia Eastment, Jean-Paul Fantognon y Michael G. Head. "COVID-19 vaccine hesitancy and conspiracy beliefs in Togo: Findings from two cross-sectional surveys". PLOS Global Public Health 4, n.º 2 (29 de febrero de 2024): e0002375. http://dx.doi.org/10.1371/journal.pgph.0002375.
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Togo is a low-income country in West Africa. Estimates from Our World in Data suggest that only 25% of the Togolese population have received at least one dose of any COVID-19 vaccine by June 2023. Whilst the early phase of the pandemic vaccine rollout across 2021 was dominated by higher-income countries taking much of the available supply, there have long been sufficient supplies for all nations. Thus, there remains a need to understand reasons for low uptake in countries such as Togo, here focusing on population confidence and trust, essentially characteristics that could potentially be addressed within health promotion strategies. Two cross-sectional telephone surveys of Togo residents were conducted in December 2020 and January 2022. These surveys asked questions around perceptions of COVID-19, trust in public health messaging, belief in conspiracy theories, and hesitancy around COVID-19 vaccination. Analyses here focus on unvaccinated respondents. Across Survey 1 (N = 1430) and Survey 2 (N = 212), 65% of respondents were men, and 47% lived in Lomé (capital city of Togo). Between Surveys 1 and 2, overall hesitancy (33.0% to 58.0% respectively) and beliefs in conspiracy theories (29% to 65%) significantly increased. Using logistics regression, governmental mistrust was the strongest significant predictor of hesitancy (OR: 2.90). Participants who indicated agreement or uncertainty with at least one conspiracy belief also predicted greater vaccine hesitancy (OR: 1.36). Proactive approaches to public health messaging, that better understand reasons for hesitancy across different demographics, can support uptake of COVID-19 vaccinations within Togo. This includes health promotion campaigns that use locally and nationally trusted knowledge providers (e.g. the health service or religious leaders) for greatest effectiveness at reducing impact of misinformation. Key future research should focus around knowledge gaps and areas of mistrust created by the pandemic, such as the impact of misinformation upon routine immunisation uptake.
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Lee, B. P., J. Green y S. T. Chiang. "Responses of single phrenic motoneurons to altered ventilatory drives in anesthetized dogs". Journal of Applied Physiology 68, n.º 5 (1 de mayo de 1990): 2150–58. http://dx.doi.org/10.1152/jappl.1990.68.5.2150.
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We studied the effects of altered ventilatory drives on the activity of the whole phrenic nerve and single phrenic motoneurons in dogs anesthetized with alpha-chloralose and paralyzed with gallamine triethiodide. Single phrenic motoneurons were classified as either late-onset or early-onset motoneurons (LOM and EOM, respectively), depending on the time of onset of their activity during inspiration. Increase in ventilatory drive was induced by altering chemical drive with changes in arterial blood gases and also by altering the vagal afferent contribution to ventilatory drive. The latter was accomplished by inducing pulmonary gas embolism (PGE) during hyperoxia. Whole phrenic nerve activity was increased by both types of increase in ventilatory drive. In both cases, changes in the firing pattern of LOMs and EOMs were responsible for the increased phrenic output. The changes in post-PGE firing pattern of the LOMs generally consisted of a shift in the time of onset to an earlier point in inspiration and an increase in the number of spikes per inspiratory cycle. Vagotomy abolished the difference between the contributions of LOMs and EOMs to the phrenic response to PGE. Data from dogs studied while they were breathing spontaneously were qualitatively the same as those from the paralyzed animals, indicating no major role for phasic volume feedback in these responses. Our data regarding altered chemical drive are similar to those reported earlier in other species, whereas those regarding PGE demonstrate that vagally mediated increases in ventilatory drive affect both LOMs and EOMs, although LOMs are affected to a greater degree.(ABSTRACT TRUNCATED AT 250 WORDS)
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Butler Pagnotti, Rachel M., Le Hanh Hua y Justin B. Miller. "A-70 Differences in Cognition and Disease Characteristics in Adult Vs. Late Onset Multiple Sclerosis". Archives of Clinical Neuropsychology 36, n.º 6 (30 de agosto de 2021): 1112. http://dx.doi.org/10.1093/arclin/acab062.88.
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Abstract Objective Cognitive impairment is a common sequelae of multiple sclerosis(MS), however, relatively little is known about cognitive impairment in late-onset MS (LOMS; symptom onset >50 years old). The present study investigated differences in disease characteristics and cognition in LOMS and adult-onset MS (AOMS). Methods Archival medical records and neuropsychological evaluations from an MS specialty center were reviewed. Differences in disease characteristics between 57 LOMS and 124 AOMS patients were compared using chi-square or ANOVA. To investigate differences in cognitive functioning, age-adjusted standardized scores were compared via ANCOVA, using cardiac risk factors and disease duration as covariates. Results Compared to AOMS (age range: 21–88; mean age: 49.66 +/−12.83), LOMS patients (age range 42–82; mean age: 61.88 +/− 8.57) had significantly more cardiac comorbidities (mean: 1.12+/−1.1 vs. 0.6+/−0.9; p < 0.01), shorter disease duration (mean years: 13.14+/−7.9 vs. 21.0+/−12.6; p < 0.001), and shorter time to diagnosis (mean years: 3.0+/−4.2 vs 6.5+/−8.5; p < 0.01). LOMS patients had similar Expanded Disability Status Scale scores and number of prescribed disease-modifying therapy as AOMS. LOMS patients demonstrated greater impairment on Brief Visuospatial Memory Test-Revised learning (F(1,169) = 8.03, p < 0.05; d = 0.36) and delayed recall (F(1,169) = 4.44, p < 0.05; d = 0.27), and on Wechsler Adult Intelligence Scale-4th edition Digit Span Backward (F(1,176) = 5.68, p < 0.05; d = 0.41) and Sequencing (F(1, 176) = 11.90, p < 0.001; d = 0.55) subtests. Conclusion Despite a shorter disease duration and quicker diagnosis, LOMS patients demonstrate similar levels of physical impairment. Moreover, even after accounting for differences in disease duration and cardiac risk, LOMS showed a greater burden of cognitive impairment than AOMS, which taken together, suggests an elevated rate of disease progression in LOMS.
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Chick, John H., Alex P. Levchuk, Kim A. Medley y John H. Havel. "Underestimation of rotifer abundance a much greater problem than previously appreciated". Limnology and Oceanography: Methods 8, n.º 3 (marzo de 2010): 79–87. http://dx.doi.org/10.4319/lom.2010.8.0079.
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Guillemin, Francis, Cédric Baumann, Jonathan Epstein, Philippe Kerschen, Teresa Garot, Guillaume Mathey y Marc Debouverie. "Older Age at Multiple Sclerosis Onset Is an Independent Factor of Poor Prognosis: A Population-Based Cohort Study". Neuroepidemiology 48, n.º 3-4 (2017): 179–87. http://dx.doi.org/10.1159/000479516.
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Background: Late-onset multiple sclerosis (LOMS) frequently features a primary progressive (PP) course, strongly predicting severe disability. In this population-based cohort, we estimated the prognostic role of age at multiple sclerosis (MS) onset, independent of PP course, on disability progression. Methods: The association of age at disease onset (adult, <50 years [AOMS], vs. late, ≥50 years [LOMS]) and time to Expanded Disability Status Scale (EDSS) score 4 and 6 was estimated by Cox regression modelling. Results: Among 3,597 patients, 245 had LOMS. Relapsing-remitting (RR) disease was less frequent with LOMS than AOMS (51.8 vs. 90.8%, p < 0.0001). PP course, LOMS and male gender predicted short time to EDSS 4 and 6. Worse outcome with LOMS (time to EDSS 4 and 6, HR 2.0 [95% CI 1.7-2.4] and 2.3 [1.9-2.9]) was independent of PP course or male gender. LOMS had greater impact on RR than PP disease (time to EDSS 4 and 6, HR 3.1 [2.3-4.0] and 4.0 [2.9-5.6]). Only LOMS predicted time from EDSS 4 to 6 (p < 0.0001). Conclusions: Late onset MS was strongly associated with poor prognosis, independent of initial disease course, in predicting the disability progression along time.
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Nasiri, Ehsan, Amirreza Naseri, Pouya Abbasgholizadeh, Ali Fahidi y Mahnaz Talebi. "Clinical and Epidemiological Aspects of Late Onset Multiple Sclerosis in East-Azerbaijan, Iran; A Population-Based Study". Archives of Iranian Medicine 25, n.º 11 (1 de noviembre de 2022): 725–29. http://dx.doi.org/10.34172/aim.2022.114.
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Background: Late-onset multiple sclerosis (LOMS) is defined as symptoms initiating at an age above 50. Objective: This study aims to determine the clinical and epidemiological aspects of LOMS in East-Azerbaijan province, Iran. Methods: This population-based study recruited nearly all MS patients to the end of 2020, who were diagnosed at age≥50, by referring to the only local MS registry center. We investigated prevalence, sex, age-of-onset, first clinical presentation, family history, and gap of diagnosis. Also, we compared the disease characteristics between male and female cases. Results: Out of 4905 total cases of MS, 217 cases (4.42%) were LOMS. The mean age of onset was 53.80±3.41 years with a maximum age of 68 years. The most common age group of the patients was 50 to 55 years (69.1%). The frequency by sex of LOMS in females (150) was greater than males (67). Positive family history was seen in 6.17%, and in 41% of the patients, the disease was diagnosed in a timely manner. Early symptoms were motor (31.3%), sensory (24.8%), optic neuritis (23%), cerebellar symptoms (13.8%), and brainstem symptoms (6.9%). The first presentation of the disease was different between male and female cases (P-value<0.01). Motor symptoms were the most prevalent first clinical presentation in female cases (37.6%), while in male cases, cerebellar symptoms (25.8%) were the most common. Conclusion: LOMS is not a rare condition. Increasing knowledge in the diagnosis, as well as increasing awareness of the disease in the general population, leads to early diagnosis of LOMS and prevention of consequences.
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Tan, Alex Y., Chung-Chuan Chou, Shengmei Zhou, Motoki Nihei, Chun Hwang, C. Thomas Peter, Michael C. Fishbein y Peng-Sheng Chen. "Electrical connections between left superior pulmonary vein, left atrium, and ligament of Marshall: implications for mechanisms of atrial fibrillation". American Journal of Physiology-Heart and Circulatory Physiology 290, n.º 1 (enero de 2006): H312—H322. http://dx.doi.org/10.1152/ajpheart.00369.2005.
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The importance of the ligament of Marshall (LOM) to rapid activations within the left superior pulmonary vein (LSPV) during atrial fibrillation (AF) remains poorly understood. We aimed to characterize the importance of electrical coupling between the LSPV with the left atrium (LA) and the LOM in the generation of high-frequency activations within this PV. We performed high-density mapping of the LSPV-LA-LOM junction in eight dogs, using 1,344 electrodes with a 1-mm resolution before and after posterior ostial ablation to diminish PV-LA electrical connections. A LOM potential was recordable up to 6.5 mm (SD 2.2) into the LSPV in all dogs during sinus rhythm (SR) and LA pacing. Functional LOM-LSPV electrical connections bypassing the PV-LA junction were present in five of eight dogs. Direct LOM-LSPV connections contributed to 46.5% (SD 16.0) of LSPV activations during AF, resulting in a greater propensity to develop focal activations ( P < 0.05) and a higher activation rate during AF of LSPVs with direct LOM connections compared with those without ( P < 0.03). Posterior LSPV ostial ablation without damaging the anterior wall or LOM slowed residual LA-PV conduction ( P < 0.001). This diminished PV-LA coupling prevented the reinduction of LSPV focal activations in all dogs. However, persistent LOM focal activations in two dogs continued to activate the LSPV rapidly [cycle length 151.8 ms (SD 4.8)] via direct LOM-LSPV connections. LOM-LSPV connection forms an accessory pathway that contributes to the electrical coupling between LSPV and LA during SR and AF. This pathway may contribute to rapid activations within the LSPV during AF.
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Boore, David M., Linda Seekins y William B. Joyner. "Peak Accelerations From the 17 October 1989 Loma Prieta Earthquake". Seismological Research Letters 60, n.º 4 (1 de octubre de 1989): 151–66. http://dx.doi.org/10.1785/gssrl.60.4.151.
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Abstract Peak accelerations of the Loma Prieta main shock have been tabulated from instruments maintained by a number of organizations. We have analyzed a subset of 86 records from nominally free-field sites, which have been subdivided into rock, alluvium, and bay-mud categories according to data available in various reports. After correction for attenuation, the peak accelerations on rock, alluvium, and bay-mud sites are factors of 1.6, 1.8, and 4.5 larger, on the average, than Joyner and Boore’s (1988) predicted values for a M= 6.9 earthquake. The mean motions for the rock and alluvium sites are somewhat greater than one standard deviation away from the predicted value, but the mean acceleration from the bay-mud sites is well outside the range expected from analyses of data from previous earthquakes from rock and alluvium sites. Large amplitudes of motions on bay-mud sites relative to rock sites (a factor of 2.8 for the average of the recordings of the Loma Prieta main shock) has been found previously from recordings of distant earthquakes and explosions, but the Loma Prieta earthquake provided the first opportunity to study the relative amplitudes from strong-motion recordings.
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Stewart, Jill, Paul Stewart, Tom Walker, Latha Gullapudi, Mohamed T. Eldehni, Nicholas M. Selby y Maarten W. Taal. "Application of the Lomb-Scargle Periodogram to InvestigateHeart Rate Variability during Haemodialysis". Journal of Healthcare Engineering 2020 (8 de diciembre de 2020): 1–18. http://dx.doi.org/10.1155/2020/8862074.
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Short-term cardiovascular compensatory responses to perturbations in the circulatory system caused by haemodialysis can be investigated by the spectral analysis of heart rate variability, thus providing an important variable for categorising individual patients’ response, leading to a more personalised treatment. This is typically accomplished by resampling the irregular heart rate to generate an equidistant time series prior to spectral analysis, but resampling can further distort the data series whose interpretation can already be compromised by the presence of artefacts. The Lomb–Scargle periodogram provides a more direct method of spectral analysis as this method is specifically designed for large, irregularly sampled, and noisy datasets such as those obtained in clinical settings. However, guidelines for preprocessing patient data have been established in combination with equidistant time-series methods and their validity when used in combination with the Lomb–Scargle approach is missing from literature. This paper examines the effect of common preprocessing methods on the Lomb–Scargle power spectral density estimate using both real and synthetic heart rate data and will show that many common techniques for identifying and editing suspect data points, particularly interpolation and replacement, will distort the resulting power spectrum potentially misleading clinical interpretations of the results. Other methods are proposed and evaluated for use with the Lomb–Scargle approach leading to the main finding that suspicious data points should be excluded rather than edited, and where required, denoising of the heart rate signal can be reliably accomplished by empirical mode decomposition. Some additional methods were found to be particularly helpful when used in conjunction with the Lomb–Scargle periodogram, such as the use of a false alarm probability metric to establish whether spectral estimates are valid and help automate the assessment of valid heart rate records, potentially leading to greater use of this powerful technique in a clinical setting.
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Loss, Arcângelo, Marcos Gervasio Pereira, Sidinei Julio Beutler, Adriano Perin, Marisa de Cassia Piccolo, Shirlei Almeida Assunção y Everaldo Zonta. "THE IMPACT OF AGRICULTURAL SYSTEMS IN THE SOIL ORGANIC MATTER CONTENT IN BRAZILIAN CERRADO". International Journal of Research -GRANTHAALAYAH 7, n.º 8 (31 de agosto de 2019): 220–44. http://dx.doi.org/10.29121/granthaalayah.v7.i8.2019.662.
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Were quantified the plant residues on the soil, total soil organic carbon (TOC) and nitrogen (TN) contents and the different soil organic matte (SOM) fractions and to determine 13C and 15N isotopic soil composition and plant residues in the crop–livestock integration system (CLIS), pasture and Cerrado areas, in Goias, Brazil. TOC and TN, C and N light organic matter content (C-LOM/N-LOM); C and N of particulate organic matter (C-POM/N-POM); and mineral organic matter (C-MOM/N-MOM) were evaluated. δ13C and δ15N of soil and LOM, POM, and MOM fractions, as well as the δ13C of plant residues, were also determined. Plant residues from pasture were more enriched with nutrients and C, and CLIS which are richer in N. δ13C of pasture and CLIS soils indicated that the C from the Cerrado vegetation (typically C3) was replaced by vegetation with C4 photosynthetic mechanisms. CLIS accumulated more TOC than the pasture, and provided higher C-MOM and N-MOM values than pasture, and higher N-LOM levels than pasture and Cerrado. δ13C of LOM is associated with more recent origins of carbon. δ15N of POM and soil of the CLIS and pasture indicate greater mineralization of SOM.
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Le Hong Ngoc, Tran, Ha Thi Xuan Chi, Pham Son Minh, Van-Thuc Nguyen y Tran Minh The Uyen. "Movement Strategy Influences on the Characteristics of Low-Carbon Steel Generated by the Lamination Object Manufacturing Method". Metals 14, n.º 3 (19 de marzo de 2024): 356. http://dx.doi.org/10.3390/met14030356.
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This paper investigates the effects of heating movement techniques on the properties of low-carbon steel samples that are 3D printed using S20C lamination object manufacturing (LOM). A Tungsten iner gas (TIG) machine and a computer numerical control (CNC) machine were used together to join the steel sheet. The LOM samples were created with a straight-profile, short-profile, cross-profile, and curved-profile. The results indicate that the majority of the samples had a grain size number of 7–9. The samples exhibited an isotropy grain shape. The LOM samples exhibited dimples, which suggests ductility fractures. Pore flaws showed up in the microstructure of the cross-profile and short-profile samples during the LOM process. The samples with curved- and straight-profiles had a better microstructure. In comparison to samples with a short profile and a cross-profile, the samples with a straight-profile and a curved-profile had a superior combination of ultimate tensile strengths (UTSs) and elongation value. The straight- and curved-profiles’ greater elongation and tensile strength can be attributed to their improved microstructure and finer grain size. A straight-profile sample with an elongation value of 25.6% and a UTS value of 430 MPa was the ideal LOM sample. Conversely, the weakest sample was the LOM sample with a cross-profile, which had an elongation value of 10.8% and a UTS value of 332.5 MPa. This research could provide further information about the LOM method and the best straight-profile movement strategy. A suitable TIG gun movement strategy could produce a good LOM sample with a good microstructure, tensile strength, and ductility. Further research should incorporate more movement strategies and techniques that completely prevent the formation of pore defects.
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Lee, Tien‐Chang, Shawn Biehler, Stephen K. Park y William J. Stephenson. "A seismic refraction and reflection study across the central San Jacinto Basin, Southern California". GEOPHYSICS 61, n.º 5 (septiembre de 1996): 1258–68. http://dx.doi.org/10.1190/1.1444050.
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The San Jacinto Basin is a northwest‐trending, pull‐apart basin in the San Jacinto fault zone of the San Andreas fault system in southern California. About 24 km long and 2 to 4 km wide, the basin sits on a graben bounded by two strands of the San Jacinto fault zone: the Claremont Fault on the northeast and the Casa Loma Fault on the southwest. We present a case study of shallow structure (less than 1 km) in the central basin. A 2.75-km refraction line running from the northeast to southwest across the regional structural trend reveals a groundwater barrier (Offset I). Another line, bent southward and continued for 1.65-km, shows a crystalline basement offset (Offset III) near an inferred trace of the Casa Loma Fault. Although a basement refractor was not observed along the 2.75-km line, a mismatch between the estimate of its minimum depth and the basement depth determined for the 1.65-km line suggests that an offset in the basement (greater than 260 m) exists around the junction of the two refraction lines (Offset II). By revealing more faults and subtle sedimentary structures, the reflection stack sections confirm the two refraction offsets as faults. Offsets I and III each separate sediments of contrasting structures and, in addition, Offset III disrupts an unconformity. However, the sense and amount of the offset across Offset III contradict what may be expected across the Casa Loma Fault, which has its basinward basement down‐thrown to about 2.5 km in the better defined southeastern part of the graben. The Casa Loma Fault trace has been mislinked in the existing geological maps and the trace should be remapped to Offset II where the reflector disruptions spread over a 400-m wide zone. Our Offset III is an unnamed, concealed fault.
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Phillips, Brenda D. "Cultural Diversity in Disasters: Sheltering, Housing, and Long Term Recovery". International Journal of Mass Emergencies & Disasters 11, n.º 1 (marzo de 1993): 99–110. http://dx.doi.org/10.1177/028072709301100108.
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Demographic shifts have put minority groups and the poor at greater risk to disaster during the last decade. Problems of sheltering and housing for these groups occurred following the 1989 Loma Prieta earthquake in Watsonville, California. To mitigate future problems, disaster planners must identify various ethnic groups and other groups in a community. Diversity must be built into the disaster response during the planning stage. Researchers should continue and expand work related to diversity and disaster.
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Wald, David J., Hiroo Kanamori, Donald V. Helmberger y Thomas H. Heaton. "Source study of the 1906 San Francisco earthquake". Bulletin of the Seismological Society of America 83, n.º 4 (1 de agosto de 1993): 981–1019. http://dx.doi.org/10.1785/bssa0830040981.
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Abstract All quality teleseismic recordings of the great 1906 San Francisco earthquake archived in the 1908 Carnegie Report by the State Earthquake Investigation Commission were scanned and digitized. First order results were obtained by comparing complexity and amplitudes of teleseismic waveforms from the 1906 earthquake with well calibrated, similarly located, more recent earthquakes (1979 Coyote Lake, 1984 Morgan Hill, and 1989 Loma Prieta earthquakes) at nearly co-located modern stations. Peak amplitude ratios for calibration events indicated that a localized moment release of about 1 to 1.5 × 1027 dyne-cm was responsible for producing the peak the teleseismic body wave arrivals. At longer periods (50 to 80 sec), we found spectral amplitude ratios of the surface waves require a total moment release between 4 and 6 × 1027 dyne-cm for the 1906 earthquake, comparable to previous geodetic and surface wave estimates (Thatcher, 1975). We then made a more detailed source analysis using Morgan Hill S body waves as empirical Green's Functions in a finite fault subevent summation. The Morgan Hill earthquake was deemed most appropriate for this purpose as its mechanism is that of the 1906 earthquake in the central portion of the rupture. From forward and inverse empirical summations of Morgan Hill Green's functions, we obtained a good fit to the best quality teleseismic waveforms with a relatively simple source model having two regions of localized strong radiation separated spatially by about 110 km. Assuming the 1906 epicenter determined by Bolt (1968), this corresponds with a large asperity (on the order of the Loma Prieta earthquake) in the Golden Gate/San Francisco region and one about three times larger located northwest along strike between Point Reyes and Fort Ross. This model implies that much of the 1906 rupture zone may have occurred with relatively little 10 to 20 sec radiation. Consideration of the amplitude and frequency content of the 1906 teleseismic data allowed us to estimate the scale length of the largest asperity to be less than about 40 km. With rough constraints on the largest asperity (size and magnitude) we produced a suite of estimated synthetic ground velocities assuming a slip distribution similar to that of the Loma Prieta earthquake but with three times as much slip. For purposes of comparison with the recent, abundant Loma Prieta strong motion data set, we “moved” the largest 1906 asperity into Loma Prieta region. Peak ground velocity amplitudes are substantially greater than those recorded during the Loma Prieta earthquake, and are comparable to those predicted by the attenuation relationship of Joyner and Boore (1988) for a magnitude MW = 7.7 earthquake.
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McNeill, Andrew, Michael Gowanlock, Michael Mommert, David E. Trilling, Joe Llama y Nicholas Paddock. "An Untargeted Survey of the Rotational Properties of Main-belt Asteroids using the Transiting Exoplanet Survey Satellite (TESS)". Astronomical Journal 166, n.º 4 (8 de septiembre de 2023): 152. http://dx.doi.org/10.3847/1538-3881/acf194.
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Abstract We present photometric data for minor planets observed by the Transiting Exoplanet Survey Satellite during its Cycle 1 operations. In total, we extracted usable detections for 37,965 objects. We present an examination of the reliability of the rotation period and light-curve amplitudes derived from each object based upon the number of detections and the normalized Lomb–Scargle power of our period fitting and compare and contrast our results with previous similar works. We show that for objects with 200 or more photometric detections and a derived normalized, generalized Lomb–Scargle power greater than 0.2, we have an 85% confidence in that period; this encompasses 3492 rotation periods we consider to be highly reliable. We independently examine a series of periods first reported by Pál et al.; periods derived in both works found to have similar results should be considered reliable. Additionally, we demonstrate the need to properly account for the true proportion of slow rotators (P > 100 hr) when inferring shape distributions from sparse photometry.
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Catchings, R. D. y W. M. Kohler. "Reflected seismic waves and their effect on strong shaking during the 1989 Loma Prieta, California, earthquake". Bulletin of the Seismological Society of America 86, n.º 5 (1 de octubre de 1996): 1401–16. http://dx.doi.org/10.1785/bssa0860051401.
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Abstract Our data indicate that critical and postcritical reflections from crustal layers and the Moho produced increased shaking at discrete distances along the San Francisco Peninsula during the 1989 Loma Prieta earthquake. These reflections may have produced an increase in amplitude that is as much as 10 times greater than that of the direct arrival. Peak amplitude-distance patterns measured from explosive sources, synthetic seismograms, aftershocks, and the mainshock of the 1989 Loma Prieta earthquake indicate that (1) point sources, such as explosions, produce similar peak amplitude-distance relations as distributed, double-couple sources when the crustal structure is approximately a Poisson solid; (2) peak amplitudes from smaller point sources (explosions) may be scaled to those of larger sources (earthquakes); and (3) reflections caused a pattern of high amplitudes at specific distances along the San Francisco Peninsula that geographically correlates with areas of reported damage following from the Loma Prieta mainshock. Our study indicates that critical and postcritical reflections were stronger influences on the locations of strong shaking than local geology because a number of sites around the San Francisco Bay that are underlain by unconsolidated sediments experienced much less shaking than sites that were underlain by hard rock. Furthermore, some severely shaken hard-rock sites were farther from the epicenter than many of the less severely shaken “soft-sediment” sites. Models of the regional crustal structure and seismic-wave propagation paths may be useful in identifying sites around the San Francisco Bay region that are at risk due to reflected seismic energy, and this type of analysis may be useful in other seismically active regions.
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Zelada Estraver, William, Cesar Medina Tafur, César Chávez Villavicencio, Cesia Rodríguez Ruiz y María Seminario Rebolledo. "FLORAL VISIT BY HUMMINGBIRDS ON A COASTAL HILL IN THE NORTH OF THE PACIFIC DESERT, DURING 2021". REBIOL 42, n.º 2 (19 de abril de 2023): 213–22. http://dx.doi.org/10.17268/rebiol.2022.42.02.16.
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The Hill of Cerro Campana located in the north of the desert of the Pacific, is a unique ecosystem to host a high and specialbiological diversity, within which we find the "hummingbird ", very active and colorful bird species that feed on nectar and flower pollen. The objective of this work was to determine the number of interactions or visits of the hummingbirds to the species of flowering plants in the ACP Lomas del Cerro Campana, during 2021. For which were made 24 fixed points of counting, randomly distributed between the windward and leeward sides of this ridge and where interactions or visits to the flower of plants were recorded by the species of hummingbirds identified by direct and auditory observation. The presence of: Amazilia amazilia, Myrtis fanny, Myrmia micruraand Rhodopis vesper; birds that fed on the flowers of 20 plant species, belonging to 17 genera and 10 families; finding that Amazilia had preference for 16 plant species, Myrtis fannyby 06 species, Myrmia micruraby 08 species and Rhodopis vesperby 11 species of plants. These birds had a greater preference for interaction or visits by the flowers of species of the families Cactaceae, Bromeliaceae and Capparaceae. The plant species with which they had a greater number of interactions were: Puya ferruginea, with 12 interactions; Espostoa melanostele, Opuntia quitensiswith 9 each, Colicodendron scabridumwith 7; Tillandsia multiflora and Haageocereus decumbenswith 6 interactions each. These species, besides playing an important role in pollination, are an alternative to promote ecotourism in this ACP.
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Khan, R. A. y C. Tuck. "Parasites as biological indicators of stocks of Atlantic cod (Gadus morhua) off Newfoundland, Canada". Canadian Journal of Fisheries and Aquatic Sciences 52, S1 (1 de agosto de 1995): 195–201. http://dx.doi.org/10.1139/f95-527.
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Atlantic cod (Gadus morhua) were collected from six locations on the continental shelf off Newfoundland, Canada, including one inshore area and examined for parasites from 1981 to 1983. The protozoan Loma branchialis was more prevalent in North Atlantic Fisheries Organization (NAFO) areas 3Pn-4R (Gulf of St. Lawrence) and 2J-3K (Labrador), whereas the acanthocephalan Echinorhynchus gadi was more abundant in the latter than in other locations. Similarly, the prevalence and (or) abundance of the fillet-inhabiting larval nematode Pseudoterranova decipiens and the blood-feeding copepod Lernaeocera branchialis were significantly greater in fish from 3Ps (St. Pierre Bank) and 3Pn-4R than from all adjacent areas. Gastrointestinal ascaridoid nematodes were more abundant in 3M (Flemish Cap) cod than in other localities. No differences in the prevalence and abundance of E. gadi were detected in samples in relation to sex or size class. Paired comparisons of transformed data for the different parasite taxa revealed that there were more significant differences than similarities in cod sampled from adjacent NAFO divisions. These observations based on selected parasites (Loma branchialis, Trypanosoma murmanensis, Myxidium gadi, P. decipiens, gastrointestinal ascaridoid nematodes, E. gadi, and Lernaeocera branchialis) support the view that discrete stocks of cod inhabit the Newfoundland–Labrador continental shelf.
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Das, Dr Neelam. "The Hammock Proposal: A Modification of Loma Linda Pouch Technique". South Asian Research Journal of Oral and Dental Sciences 4, n.º 3 (12 de julio de 2022): 33–36. http://dx.doi.org/10.36346/sarjods.2022.v04i03.002.
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Introduction: A technique, the "Loma Linda pouch," is introduced for repairing the perforated maxillary sinus membrane during sinus grafting procedures. The collagen membrane is then folded along the lateral access window to form a pouch that surrounds and isolates the graft material. In this review, we planned to devise a modification to the “Loma Linda pouch technique”. This ‘‘hammock’’ approach immobilizes the collagen membrane as far as possible, promotes greater blood supply, thereby increasing vital bone formation. Case presentation: When perforation occurs during elevation of the Schneiderian membrane, elevation of the membrane from the internal sinus walls must be completed. In this approach, plasma rich in growth factors is used as a graft carrier to achieve a more compact and homogeneous bone graft and to avoid particle dispersion. The rest of the procedure follows the classic sinus augmentation approach. Discussion: Ranges of techniques involve repairing perforations that range in size from 2 mm to 1.5 cm. For larger perforations (≥1.5mm), the only reported possibility is the use of a resorbable collagen membrane. Displacement of the collagen membrane is one of the most frequent complications. For this reason, perfect immobilization of the membrane is the key to success. Compared with other methods, this modified approach enhances the fixation of the collagen membrane not only on the buccal side but also on the palatal side of the sinus cavity. Conclusion: This technique achieves stable immobilization of the collagen membrane and, with it, better treatment predictability in future.
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Thiel, Charles C., James E. Schneider, Donald Hiatt y Michael E. Durkin. "9-1-1 EMS Process in the Loma Prieta Earthquake". Prehospital and Disaster Medicine 7, n.º 4 (diciembre de 1992): 348–58. http://dx.doi.org/10.1017/s1049023x00039765.
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AbstractThe Santa Cruz County 9-1-1 emergency response system was taxed severely with over 1,000 calls during the first seven hours following the Loma Prieta earthquake. It remained functional and responsive, making 229 ambulance runs in the 72-hour period following the earthquake. Initially, the demand was very high compared to normal, but decreased to slightly greater than normal levels during the second day. A fewer than normal number of advanced life support transports were required, and the number of vehicular accident cases were fewer than normal following the earthquake. The 9-1-1 center adopted an abbreviated procedure and only attempted to determine if the call was a medical emergency and the location for dispatch. During the initial emergency period, there were an unusually low proportion of transports and an unusually high number of cases in which the patient was not located. The medical system in Santa Cruz County was able to accommodate the injury load: the health care system was extensive; its three community hospitals were not damaged severely; and there was light demand.Based on this experience, a revised 9-1-1 emergency medical services (EMS) procedure is recommended for disaster periods: 1) the dispatcher inquires whether the patient can be transported by other means; 2) the caller is asked to explain the need for an ambulance in order to assign a priority to the request; and 3) the caller is asked to cancel the call if there no longer is a need. This procedure is expected to improve disaster management of limited ambulance resources during and following a disaster, while maintaining rapid call processing.
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Wilcox, R. Bruce, Jerald C. Nelson y Ray T. Tomei. "Heterogeneity in affinities of serum proteins for thyroxine among patients with non-thyroidal illness as indicated by the serum free thyroxine response to serum dilution". European Journal of Endocrinology 131, n.º 1 (julio de 1994): 9–13. http://dx.doi.org/10.1530/eje.0.1310009.
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Wilcox RB, Nelson JC, Tomei RT. Heterogeneity in affinities of serum proteins for thyroxine among patients with non-thyroidal illness as indicated by the serum free thyroxine response to serum dilution. Eur J Endocrinol 1994;131:9–13. ISSN 0804–4643 Some patients with non-thyroidal illness (NTI) have sera with characteristics suggesting decreased functional affinity of thyroxine-binding globulin (TBG) for T4: increased T4 free fraction, decreased total T4 to TBG ratio, and a fall in free T4 with serum dilution greater than theoretical predictions assuming normal affinity. These studies aimed to further characterize this phenomenon. According to the law of mass action binding protein affinity for T4 can be estimated from the response of free T4 to progressive serum dilution. Free T4 responses in 25 normal controls and in 7 congenital TBG deficient controls resembled the predictions from the law of mass action. Among 25 of 38 medical intensive care unit patients, responses were intermediate between normals and TBG deficiency. Responses in the other 13 NTI were consistent with the presence of a dissociable inhibitor. In this subgroup, total T4 was depressed, both free T4 and TSH were elevated, and there was a positive correlation between TSH and free T4 (r2 = 0.41, p < 0.02). Conclusions: (i) decreased affinities of serum proteins for T4 consistent with binding inhibitor(s) are found in some patients with NTI; (ii) there is an association of these severely altered affinities with reversal of the expected free T4–TSH relationship. R Bruce Wilcox, Department of Biochemistry, Loma Linda University, Loma Linda, CA 92350 USA
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Okukpon, Juno Ohiremere y Oluwashola Michael Ojo. "Corneal curvature in young high myopic undergraduates in southern Nigeria". International Journal of Research in Medical Sciences 6, n.º 8 (25 de julio de 2018): 2592. http://dx.doi.org/10.18203/2320-6012.ijrms20182975.
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Background: Corneal curvature is important for contact lens fitting and management, ocular aberration analysis, corneal refractive surgery as well as diagnoses and management of corneal pathological conditions such as keratoconus and it is also an important biometric factor affecting refractive errors, myopia inclusive.Methods: This was an observational cross-sectional study conducted at the Optometry Teaching Clinic, Department of Optometry, University of Benin, Benin City, Edo State, Nigeria. Two hundred and twenty myopic eyes of 113 (54 males, 59 females) undergraduates students, between 16 and 25 years with myopia of -5.00 to -20.50 participated in this study. Non-cycloplegic refraction was done by retinoscopic measurement and spherical equivalent refraction (SER) of the eyes was calculated. The corneal curvature was determined with a Bausch and Lomb one position Keratometer (Bausch and Lomb Corp., USA).Results: The mean age, spherical equivalent, corneal curvature and corneal power were 20.44±2.24 years, ̶7.12±3.14DS, 7.72±0.26mm and 43.77±1.48D respectively. Most of the students had a myopia of -5.75 to -10.50DS (46.8%) and a corneal curvature of 7.61-7.90mm (46.82%). There was a difference between the corneal curvature of males and females (P=0.0001). A relationship was also found with gender and corneal curvature (P=0.001).Conclusions: This study found that high myopic females had shorter corneal curvature, with greater corneal powers than their males counterparts (P<0.01). We also found that gender had a significant relationship with the corneal curvature unlike age and the spherical equivalent which showed no relationship (P>0.01).
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Flanigan, James E. y Gerd Gäde. "On the Release of the Three Locust (Locusta migratoria) Adipokinetic Hormones: Effect of Crustacean Cardioactive Peptide and Inhibition by Sugars". Zeitschrift für Naturforschung C 54, n.º 1-2 (1 de febrero de 1999): 110–18. http://dx.doi.org/10.1515/znc-1999-1-219.
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An existing test to monitor the rate of adipokinetic hormone release from the corpora cardiaca (C C) of Locusta migratoria in vitro was improved, so that a constant basal rate of release was achieved and the amount of released Lom-AKH-I, II and III could be quantified by HPLC . This test system was subsequently used to demonstrate that a small peptide, which has been found in a few insect species including L. migratoria, crustacean cardioactive peptide (CCAP), induces release of all three AKHs. Moreover, 80 mᴍ trehalose reduces CCAP-induced release of AKHs in vitro, and 160 mᴍ glucose reduces this release even further. Glucose also had a greater inhibitory effect than trehalose on the spontaneous release and inhibited the high potassium-stimulated release of AKH from the CC in vitro. Eighty mᴍ sucrose, on the other hand, had no effect on the release of AKH . The effect of trehalose and glucose could be due to their use as an energy source, with trehalose first having to be converted to glucose. Whatever the stimulus, the three AKHs are released in the same proportions as they are found in the CC, which in vivo would make Lom-AKH-I, the most abundant AKH, the major effector of the biological effects of AKHs in adult locusts
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Nyaban, Christian Emile, Théophile Ndougsa-Mbarga, Marcelin Bikoro-Bi-Alou, Stella Amina Manekeng Tadjouteu y Stephane Patrick Assembe. "Multi-scale analysis and modelling of aeromagnetic data over the Bétaré-Oya area in eastern Cameroon, for structural evidence investigations". Solid Earth 12, n.º 4 (6 de abril de 2021): 785–800. http://dx.doi.org/10.5194/se-12-785-2021.
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Abstract. This study was carried out in the Lom series in Cameroon, at the border with Central African Republic, located between the latitudes 5∘30′–6∘ N and the longitudes 13∘30′–14∘45′ E. A multi-scale analysis of aeromagnetic data combining tilt derivative, Euler deconvolution, upward continuation, and 2.75D modelling was used. The following conclusions were drawn. (1) Several major families of faults were mapped. Their orientations are ENE–WSW, E–W, NW–SE, and N–S with a NE–SW prevalence. The latter are predominantly sub-vertical with NW and SW dips and appear to be prospective for future mining investigations. (2) The evidence of compression, folding, and shearing axis was concluded from superposition of null contours of the tilt derivative and Euler deconvolution. The principal evidence of the local tectonics was due to several deformation episodes (D1, D2, and D4) associated with NE–SW, E–W, and NW–SE events, respectively. (3) Depths of interpreted faults range from 1000 to 3400 m. (4) Several linear structures correlating with known mylonitic veins were identified. These are associated with the Lom faults and represent the contacts between the Lom series and the granito-gneissic rocks; we concluded the intense folding was caused by senestral and dextral NE–SW and NW–SE stumps. (5) We propose a structural model of the top of the crust (schists, gneisses, granites) that delineates principal intrusions (porphyroid granite, garnet gneiss, syenites, micaschists, graphite, and garnet gneiss) responsible for the observed anomalies. The 2.75D modelling revealed many faults with a depth greater than 1200 m and confirmed the observations from reduced-to-Equator total magnetic intensity (RTE-TMI), tilt derivative, and Euler deconvolution. (6) We developed a lithologic profile of the Bétaré-Oya basin.
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Qiao 乔, Peiyun 佩云, Tingting 婷婷 Xu 许, Feng 锋. Wang 王, Ying 盈. Mei 梅, Hui 辉. Deng 邓, Lei 磊. Tan 谈 y Chao 超. Liu 刘. "A Classification Catalog of Periodic Variable Stars for LAMOST DR9 Based on Machine Learning". Astrophysical Journal Supplement Series 272, n.º 1 (16 de abril de 2024): 1. http://dx.doi.org/10.3847/1538-4365/ad3452.
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Abstract Identifying and classifying variable stars is essential to time-domain astronomy. The Large Area Multi-Object Fiber Optic Spectroscopic Telescope (LAMOST) acquired a large amount of spectral data. However, there is no corresponding variable source-related information in the data, constraining LAMOST data utilization for scientific research. In this study, we systematically investigated variable source classification methods for LAMOST data. We constructed a 10-class classification model using three mainstream machine-learning methods. Through performance comparison, we chose the LightGBM and XGBoost models. We further identified variable source candidates in the r band in LAMOST DR9 and obtained 281,514 variable source candidates with probabilities greater than 95%. Subsequently, we filtered out the sources of periodic variable sources using the generalized Lomb–Scargle periodogram and classified these periodic variable sources using the classification model. Finally, we propose a reliable periodic variable star catalog containing 176,337 stars with specific types.
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Lee, Dongyoun y Junho Hong. "Development of an Adaptive Slicing Algorithm of Laminated Object Manufacturing Based 3D Printing for Freeform Formwork". Buildings 12, n.º 9 (30 de agosto de 2022): 1335. http://dx.doi.org/10.3390/buildings12091335.
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Recently, as “Freeform buildings” have increased in number, studies on ways to increase productivity in the construction of freeform buildings are increasing. In the case of 3D printing in construction, many studies are being conducted using the material extrusion method; among the 3D printing methods, manufacturing freeform forms using laminated object manufacturing (LOM) can overcome the limitation presented above. However, there is a lack of cases used in LOM construction sites, so it is necessary to increase the productivity of construction work and study the slicing method suitable for construction. Therefore, in this paper, we propose using study criteria and adaptive slicing methods to combine both the shape error and the manufacturing time of freeform construction. A case study was conducted to verify the results of this study; the freeform concrete form manufacturing with the algorithm that proposed this study could save 66.1% of the manufacturing time compared with CNC milling, and it needs 19.8% less manufacturing time than the existing uniform slicing method. This is a result of the production of one freeform form, and it can be expected to have a greater effect if applied to many freeform forms used in construction sites. In addition, the results of this study can be used as a decision-making tool that can determine the shape and manufacturing time of production according to the on-site situation.
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Xu, Zhengyu, Susan Y. Schwartz y Thorne Lay. "Seismic wave-field observations at a dense, small-aperture array located on a landslide in the Santa Cruz Mountains, California". Bulletin of the Seismological Society of America 86, n.º 3 (1 de junio de 1996): 655–69. http://dx.doi.org/10.1785/bssa0860030655.
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Abstract A rectangular (4 by 5) array of short-period three-component seismometers with 15-m spacing was deployed to record several U.S. Geological Survey calibration explosions detonated around the Santa Cruz Mountains. The array was located at a site where an earlier station had recorded frequency-dependent polarized site resonances for aftershocks of the 1989 Loma Prieta earthquake. The site is on a hillside believed to be a landslide structure, with the near surface consisting of poorly sorted sediments and weathered rocks with dipping subsurface layers. The primary objective was to explore the site effects in this complex three-dimensional soft-rock environment, characteristic of much of the Loma Prieta source region. The direct P waves from four nearby (15 to 20 km) explosions at easterly azimuths from the array show counterclockwise arrival azimuth anomalies of 30° to 50°. These deflections are attributed to the presence of more than one dipping velocity contrast beneath the array, with dips of from 10° to 50° and dip directions generally toward the south. One such boundary may correspond to the landslide slip surface, and the presence of dipping velocity contrasts underlying the site is probably responsible for some of the observed directional site resonance. A slowness vector analysis demonstrates that arrivals early in the P coda have similar azimuthal anomalies, while later scattered arrivals come from many azimuths. Particle motions indicate that the more coherent arrivals in the coda are comprised of scattered P waves and Rayleigh waves, probably associated with scattering from the rough topography in the region. The coda displays greater spatial coherency along the hill strike than down the slope, consistent with a wedge-shaped landslide. The overall wave-field spatial coherence, CCC(f, Δx), decreases with increasing frequency, f, and spatial offset, Δx, and on average can be well represented by CCC(f, Δx) = e−cfΔx, with c = 0.6 km−1 Hz−1 for the vertical P wave in the first 1-sec window. This behavior is comparable to that found for previously studied hard-rock locations.
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Sala-Vila, Aleix, Cinta Valls-Pedret, Sujatha Rajaram, Nina Coll-Padrós, Montserrat Cofán, Mercè Serra-Mir, Ana M. Pérez-Heras et al. "Effect of a 2-year diet intervention with walnuts on cognitive decline. The Walnuts And Healthy Aging (WAHA) study: a randomized controlled trial". American Journal of Clinical Nutrition 111, n.º 3 (7 de enero de 2020): 590–600. http://dx.doi.org/10.1093/ajcn/nqz328.
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ABSTRACT Background Walnut consumption counteracts oxidative stress and inflammation, 2 drivers of cognitive decline. Clinical data concerning effects on cognition are lacking. Objectives The Walnuts And Healthy Aging study is a 2-center (Barcelona, Spain; Loma Linda, CA) randomized controlled trial examining the cognitive effects of a 2-y walnut intervention in cognitively healthy elders. Methods We randomly allocated 708 free-living elders (63–79 y, 68% women) to a diet enriched with walnuts at ∼15% energy (30–60 g/d) or a control diet (abstention from walnuts). We administered a comprehensive neurocognitive test battery at baseline and 2 y. Change in the global cognition composite was the primary outcome. We performed repeated structural and functional brain MRI in 108 Barcelona participants. Results A total of 636 participants completed the intervention. Besides differences in nutrient intake, participants from Barcelona smoked more, were less educated, and had lower baseline neuropsychological test scores than those from Loma Linda. Walnuts were well tolerated and compliance was good. Modified intention-to-treat analyses (n = 657) uncovered no between-group differences in the global cognitive composite, with mean changes of −0.072 (95% CI: −0.100, −0.043) in the walnut diet group and −0.086 (95% CI: −0.115, −0.057) in the control diet group (P = 0.491). Post hoc analyses revealed significant differences in the Barcelona cohort, with unadjusted changes of −0.037 (95% CI: −0.077, 0.002) in the walnut group and −0.097 (95% CI: −0.137, −0.057) in controls (P = 0.040). Results of brain fMRI in a subset of Barcelona participants indicated greater functional network recruitment in a working memory task in controls. Conclusions Walnut supplementation for 2 y had no effect on cognition in healthy elders. However, brain fMRI and post hoc analyses by site suggest that walnuts might delay cognitive decline in subgroups at higher risk. These encouraging but inconclusive results warrant further investigation, particularly targeting disadvantaged populations, in whom greatest benefit could be expected. This trial was registered at clinicaltrials.gov as NCT01634841.
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Pulitano, Fabiana Marise, Henrique Nery Cipriani, Luiz Eduardo Dias y Giselda Durigan. "CHEMICAL AND MICROBIOLOGICAL PROPERTIES OF AN EUTROPHIC OXISOL UNDER RIPARIAN FOREST BUFFER REFORESTATION AND PASTURE". Revista do Instituto Florestal 25, n.º 1 (31 de enero de 2013): 25–33. http://dx.doi.org/10.24278/2178-5031.2013251418.
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Regardless of their ecological importance, riparian forest strips are frequently suppressed to allow greater expansion of arable and urban areas. Agroforestry might be an effective alternative to recompose riparian forests. Soil chemical and microbial properties are important environmental indicators to evaluate the reclamation process. This study tested the hypothesis that, in the course of time, reforestation by means of agroforestry improved soil microbial and chemical properties in a riparian forest buffer. Soil samples were collected from three layers (0.0-2.5; 2.5-7.5; 7.5-20 cm) in two sectors of a reforested riparian buffer strip in Cananéia Farm, São Paulo state, Brazil, one 18 years old and other 28 years old, and in an adjacent pasture area. The samples were assessed for pHH2O, available P and K, exchangeable, Ca, Mg and Al, H+Al, sum of bases (SB), pH 7.0 CEC, percent base saturation (V), soil organic matter (SOM) and light organic matter (LOM). Microbial biomass carbon (MBC) and nitrogen (MBN) were analyzed only in the first layer. The pattern for Ca, Mg, SB and V (all layers) was 28-year-old sector = 18-year-old-sector > pasture. The SOM at 0.0-2.5 cm was higher in the 28-year-old sector. The LOM pattern was 28-year-old sector > 18-year-old sector > pasture. MBC did not differ among areas. MBN was significantly higher comparing the 28-year-old sector and the pasture area. The results probably reflected the higher litterfall and the N-richer organic matter in the reforested sectors. Reforestation by means of agroforestry improved soil quality, contributing to the ecosystem sustainability.
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Kudrys, Jacek, Dominik Prochniewicz, Fang Zhang, Mateusz Jakubiak y Kamil Maciuk. "Identification of BDS Satellite Clock Periodic Signals Based on Lomb-Scargle Power Spectrum and Continuous Wavelet Transform". Energies 14, n.º 21 (1 de noviembre de 2021): 7155. http://dx.doi.org/10.3390/en14217155.
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Onboard satellite clocks are the basis of Global Navigation Satellite Systems (GNSS) operation, and their revolution periods are at the level of 2 per day (about 12 h) in the case of the Medium Earth Orbit (MEO) satellites. In this work, the authors analysed the entire BeiDou Navigation Satellite System (BDS) space segment (BDS-2 and BDS-3) in terms of the occurrence of periodic, repetitive signals in the clock products, and checked if they coincide with the orbital periods or their multiples. The Lomb-Scargle (L-S) power spectrum was used as a tool to determine the periods present in the BDS clock products, allowing for analyses based on incomplete input data; in this case, the incomplete data were the phase data with jumps and outliers removed. In addition, continuous wavelet transform (CWT) was used to produce a time−frequency representation showing the more complex behaviour of the satellite clock products. As shown in the case of geostationary and geosynchronous inclined orbit satellites, the main period was 23.935 h, while for the Medium Earth Orbit it was 12.887 h, with the BDS satellite orbital period being 12 h 53 m (12.883 h). Some effects connected with reference clock swapping are also visible in the power spectrum. The conducted analyses showed that the BDS-2 satellite clocks have much higher noise than the BDS-3 satellite clocks, meaning that the number of designated periods is greater, but their reliability is significantly lower. BDS-3 satellites have only been in operation for a very short time, thus this is the first analysis to include this type of data. Moreover, such a wide and complex analysis has not been carried out to date.
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Wateba, Ihou Nazoba Majesté, Akouda Akessiwe Patassi, Abago Balaka y Ousséni Tidjani. "Viral Characteristic of HIV Infected Patients Naïf of Anti-Retroviral Therapy with CD4+ T Lymphocytes Rate Greater than 350 per Microliter of Blood in Lomé Togo". World Journal of AIDS 03, n.º 04 (2013): 364–66. http://dx.doi.org/10.4236/wja.2013.34047.
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Hanks, Thomas C. y A. Gerald Brady. "The Loma Prieta earthquake, ground motion, and damage in Oakland, Treasure Island, and San Francisco". Bulletin of the Seismological Society of America 81, n.º 5 (1 de octubre de 1991): 2019–47. http://dx.doi.org/10.1785/bssa0810052019.
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Abstract The basis of this study is the acceleration, velocity, and displacement wave-forms of the Loma Prieta earthquake (18 October 1989; M = 7.0) at two rock sites in San Francisco, a rock site on Yerba Buena Island, an artificial-fill site on Treasure Island, and three sites in Oakland underlain by thick sections of poorly consolidated Pleistocene sediments. The waveforms at the three rock sites display a strong coherence, as do the three sedimentary sites in Oakland. The duration of strong motion at the rock sites is very brief, suggestive of an unusually short source duration for an earthquake of this size, while the records in Oakland show strong amplification effects due to site geology. The S-wave group at Treasure Island is phase coherent with the Oakland records, but at somewhat diminished amplitudes, until the steps in acceleration at approximately 15 sec, apparently signaling the onset of liquefaction. All seven records clearly show shear-wave first motion opposite to that expected for the mainshock radiation pattern and peak amplitudes greater than expected for sites at these distances (95 ± 3 km) from an earthquake of this magnitude. While the association between these ground motion records and related damage patterns in nearby areas has been easily and eagerly accepted by seismological and engineering observers of them, we have had some difficulty in making such relationships quantitative or even just clear. The three Oakland records, from sites that form a nearly equilateral triangle about the Cypress Street viaduct collapse, are dominated by a long-period resonance (≃ 1 1/2-sec period) far removed from the natural frequency of the structure to transverse motion (2.5 Hz) or from high-frequency amplification bands observed in aftershock studies. A spectral ratio arbiter of this discrepancy confuses it further. The failure of the East Bay crossing of the San Francisco-Oakland Bay Bridge cannot be attributed to relative displacements of the abutments in Oakland and Yerba Buena Island, but the motions of the Bay Bridge causing failure remain unknown. The steps in acceleration at Treasure Island present unusual strong-motion accelerogram processing problems, and modeling suggests that the velocity and displacement waveforms are contaminated by a spurious response of the filtering operations to the acceleration steps. A variety of coincidences suggests that the Treasure island accelerogram is the most likely strong-motion surrogate for the filled areas of the Marina District, for which no mainshock records are available, but the relative contributions of bad ground, poor construction and truly strong ground motion to damage in the Marina District will never by known in any quantitative way. The principal lesson of all of this is that until a concerted effort is mounted to instrument ground and structures that are likely to fail during earthquakes, our understanding of the very complex relationships between strong ground motion and earthquake damage will, in general, remain rudimentary, imprecise, and vague.
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Norini, Gianluca y Gianluca Groppelli. "Comment on “Estimating the depth and evolution of intrusions at resurgent calderas: Los Humeros (Mexico)” by Urbani et al. (2020)". Solid Earth 11, n.º 6 (23 de diciembre de 2020): 2549–56. http://dx.doi.org/10.5194/se-11-2549-2020.
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Abstract. A multiple shallow-seated magmatic intrusion model has been proposed by Urbani et al. (2020) for the resurgence of the Los Potreros caldera floor, in the Los Humeros volcanic complex (LHVC). This model predicts (1) the occurrence of localized bulges in the otherwise undeformed caldera floor, and (2) that the faults corresponding to different bulges exhibit different spatial and temporal evolution. Published data and a morphological analysis show that these two conditions are not met at Los Potreros caldera. A geothermal well (H4), located at the youngest supposed bulge (Loma Blanca) for which Urbani et al. (2020) calculated an intrusion depth (425±170 m), does not show any thermal and lithological evidence of such a shallow-seated cryptodome. Finally, published stratigraphic data and radiometric dating disprove the proposed common genesis of Holocene resurgence faulting and viscous lavas extruded in the centre of the caldera. Even if recent shallow intrusions do exist in the area, published data indicate that the pressurization of the LHVC magmatic–hydrothermal system driving resurgence faulting occurs at greater depth. Thus, we suggest that the model and calculation proposed by Urbani et al. (2020) are unlikely to have any relevance to the location, age and emplacement depth of magma intrusions driving resurgence at the Los Potreros caldera.
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Carrazana-Escalona, Ramón, Miguel Enrique Sánchez-Hechavarría y Ariel Ávila. "Theil Entropy as a Non-Lineal Analysis for Spectral Inequality of Physiological Oscillations". Entropy 24, n.º 3 (4 de marzo de 2022): 370. http://dx.doi.org/10.3390/e24030370.
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Theil entropy is a statistical measure used in economics to quantify income inequalities. However, it can be applied to any data distribution including biological signals. In this work, we applied different spectral methods on heart rate variability signals and cellular calcium oscillations previously to Theil entropy analysis. The behavior of Theil entropy and its decomposable property was investigated using exponents in the range of [−1, 2], on the spectrum of synthetic and physiological signals. Our results suggest that the best spectral decomposition method to analyze the spectral inequality of physiological oscillations is the Lomb–Scargle method, followed by Theil entropy analysis. Moreover, our results showed that the exponents that provide more information to describe the spectral inequality in the tested signals were zero, one, and two. It was also observed that the intra-band component is the one that contributes the most to total inequality for the studied oscillations. More in detail, we found that in the state of mental stress, the inequality determined by the Theil entropy analysis of heart rate increases with respect to the resting state. Likewise, the same analytical approach shows that cellular calcium oscillations present on developing interneurons display greater inequality distribution when inhibition of a neurotransmitter system is in place. In conclusion, we propose that Theil entropy is useful for analyzing spectral inequality and to explore its origin in physiological signals.
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Wen, Peijun, Fuyun Tan, Menglai Lei, Muhammad Saddique Akbar Khan, Weihua Chen y Xiaodong Hu. "Wavelengths and irradiances modulate the circadian rhythm of Neurospora crassa". PLOS ONE 17, n.º 3 (30 de marzo de 2022): e0266266. http://dx.doi.org/10.1371/journal.pone.0266266.
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The circadian rhythm affects the biological evolution and operating mechanisms of organisms. The impact of light on the circadian rhythm is a significant concern for both biology and human well-being. However, the relation between different wavelengths, irradiances, and circadian rhythm is unknown. In this study, we compared the effects of four different monochromatic light-emitting diode (LED) light and two different irradiances on the circadian rhythm of a wild-type Neurospora crassa. The results demonstrated that the circadian rhythm of Neurospora crassa can be modulated by violet (λp = 393 nm), blue (λp = 462 nm), and green (λp = 521 nm) light, regardless of the irradiances, in the visible region. Unexpectedly, for the yellow light (λp = 591 nm), the 2 W/m2 light had a more significant impact on circadian rhythm modulation than the 0.04 W/m2 light had. Considering the highest energy of yellow light (2.25 eV) is lower than the High Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) gap of WC-1 (2.43 eV). We speculate that there may be other potential photoreceptors that are involved in circadian rhythm modulation. The HOMO-LOMO gaps of these proteins are greater than 1.98 eV and less than 2.25 eV. These results provide a strong foundation for a deeper understanding of the impact of different light on the circadian rhythm and also shed light on the identification of new circadian rhythm modulation photoreceptors.
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Kresser, S., R. Schneider, H. Zunko y C. Sommitsch. "A Model to Predict the Microstructural Constituents after Quenching and Partitioning of Martensitic Stainless Steels". HTM Journal of Heat Treatment and Materials 76, n.º 2 (1 de abril de 2021): 120–31. http://dx.doi.org/10.1515/htm-2020-0008.
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Abstract The typical heat treatment of martensitic stainless steels comprises hardening and subsequent tempering. Depending on the application and size of the component, tempering is carried out either at low temperatures (< 300 °C) or at high temperatures (> 500 °C). In this paper, tempering at lower temperatures is examined. First, the austenitizing step is considered in greater detail and an optimized formula for the calculation of the MS temperature of such steel grades is created in order to enable to be modelled. For the calculations, the austenite composition is determined at different austenitizing temperatures using thermodynamic simulation. Furthermore, the transformation of austenite into martensite during quenching is described with the help of the Koistinen-Marburger equation. The second part deals with effects in the material at low holding temperatures. Here, the influence of different hardening temperatures and interception temperatures of the quenching procedure is investigated. There is no complete partitioning at temperatures of 300 °C. Certain tempering processes can also take place, such as the formation of transition carbides, so-called M3C carbides. A typical tempering with formation of stable Cr-rich carbides does not occur at this low temperature. Finally, the calculated results of the model correlate well with microstructural investigations (XRD, LOM). ◼
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Ford, E. A. K., A. L. Aruliah, E. M. Griffin y I. McWhirter. "Thermospheric gravity waves in Fabry-Perot Interferometer measurements of the 630.0nm OI line". Annales Geophysicae 24, n.º 2 (23 de marzo de 2006): 555–66. http://dx.doi.org/10.5194/angeo-24-555-2006.
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Abstract. Gravity waves are an important feature of mesosphere - lower thermosphere (MLT) dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. It is known that some gravity waves may propagate through the mesopause and reach greater altitudes before eventually "breaking" and depositing energy. The generation, propagation, and breaking of upper thermospheric gravity waves have not been studied directly often. However, their ionospheric counterparts, travelling ionospheric disturbances (TIDs), have been extensively studied in, for example, radar data. At high latitudes, it is believed localised auroral activity may generate gravity waves in-situ. Increases in sensor efficiency of Fabry-Perot Interferometers (FPIs) located in northern Scandinavia have provided higher time resolution measurements of the auroral oval and polar cap atomic oxygen red line emission at 630.0 nm. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with periods ranging from a few tens of minutes to several hours. Oscillations are seen in the intensity of the line as well as the temperatures and line of sight winds. Instruments are located in Sodankylä, Finland; Kiruna, Sweden; Skibotn, Norway, and Svalbard in the Arctic Ocean. A case study is presented here, where a wave of 1.8 h period has a phase speed of 250 ms-1 with a propagation angle of 302°, and a horizontal wavelength of 1600 km. All the FPIs are co-located with EISCAT radars, as well as being supplemented by a range of other instrumentation. This allows the waves found in the FPI data to be put in context with the ionosphere and atmosphere system. Consequently, the source region of the gravity waves can be determined.
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Palmieri, Annalisa, Dorina Lauritano, Agnese Pellati, Luca Scapoli, Claudio Arcuri, Luigi Baggi, Roberto Gatto y Francesco Carinci. "Prevalence of Human Papillomavirus in the Oropharynx of Healthy Individuals in an Italian Population". Journal of Clinical Medicine 11, n.º 7 (31 de marzo de 2022): 1935. http://dx.doi.org/10.3390/jcm11071935.
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Oral cavity and oropharynx cancer associated with human papil loma virus infection, particularly in young people who are continuously exposed to this virus, is a serious public health problem worldwide, especially for high-risk strains that are most associated with premalignant lesions and tumors. These neoplasms remain asymptomatic for a long time and, when they occur, they are already at an advanced stage. If diagnosed and treated early, oral cancer induced by human papilloma virus allows for high survival, as it often has a more favorable prognosis than oral cancers not directly related to viral infection. In this study, the presence of different high-risk and low-risk HPV strains was investigated to assess the epidemiological status in a population of healthy individuals. Two types of samples, one from the tonsils and one from the base of the tongue, were collected from 2015 healthy individuals of different sex and age. A total of 1885 DNA samples belonging to 1285 patients were tested for the presence of 11 high-risk HPV types plus 4 low-risk HPV types using real-time PCR. Of the patients’ DNA samples screened for 15 HPV types, only four samples were positive, all of which were taken from male smokers. These results indicate that newly acquired oral oncogenic HPV infections in the healthy population are rare and, in many cases, controversial. Therefore, more studies are needed to ensure fewer variations in outcomes and a greater clarification of HPV infection and its prevalence in the oropharynx of the healthy population, and to guide efforts to prevent the development of this infection which, if undiagnosed, can lead to the onset of malignant tumors in the oral cavity.
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Dieu Souffit, Gondji, Saïdou Saïdou, Oumar Bobbo Modibo, David Lepoire y Shinji Tokonami. "Risk Assessment of Exposure to Natural Radiation in Soil Using RESRAD-ONSITE and RESRAD-BIOTA in the Cobalt-Nickel Bearing Areas of Lomié in Eastern Cameroon". Radiation 2, n.º 2 (19 de abril de 2022): 177–92. http://dx.doi.org/10.3390/radiation2020013.
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Nkamouna-Kongo is a cobalt–nickel deposit located in Lomié, Eastern Cameroon. Mining creates radiation exposure pathways that must be considered in risk management scenarios. RESRAD-ONSITE and RESRAD-BIOTA, developed by the US DOE, assess contaminated sites by deriving cleanup criteria and estimating the radiation dose and risk associated with residual radioactive materials using site-specific parameters. This paper evaluated the radiation dose in biota and the health risk from exposure to naturally occurring radionuclides. The activity of 226Ra, 232Th, and 40K was determined by γ-spectrometry. The internal doses were 2.13 × 10−07, 1.42 × 10−06, and 8.38 × 10−05 Gy d−1 for animals and 2.38 × 10−07, 2.04 × 10−06, and 9.07 × 10−05 Gy d−1 for plants. The maximum total dose of 0.7234 mSv yr−1 was obtained at t = 1 year. The external dose contribution obtained at t = 1 year for all nuclides summed and all component pathways was 0.4 mSv yr−1, above the background radiation dose limit of 2.5 × 10−01 mSv yr−1. A maximum cancer risk of 1.36 × 10−03 was observed at t = 1 year. It was also shown in the RESRAD calculations that the total cancer morbidity risks from plant ingestion, radon (independent of water), and external gamma exposure pathways were greater than those from other exposure pathways. The high risk calculated for 226Ra relative to 232Th and 40K makes it the primary human health concern in the study area. The use of a 1 m cover thickness would remediate the contaminated site to a dose on the order of 10−5 mSv yr−1 for a period of 0 to 100 years. The values of these doses are below the US DOE recommended limits.
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Borcherdt, Roger D. y Gary Glassmoyer. "On the characteristics of local geology and their influence on ground motions generated by the Loma Prieta earthquake in the San Francisco Bay region, California". Bulletin of the Seismological Society of America 82, n.º 2 (1 de abril de 1992): 603–41. http://dx.doi.org/10.1785/bssa0820020603.
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Abstract Strong ground motions recorded at 34 sites in the San Francisco Bay region from the Loma Prieta earthquake show marked variations in characteristics dependent on crustal structure and local geological conditions. Peak horizontal acceleration and velocity inferred for sites underlain by “rock” generally occur on the transverse component of motion. They are consistently greater with lower attenuation rates than the corresponding mean value predicted by empirical curves based on previous strong-motion data. Theoretical amplitude distributions and synthetic seismograms calculated for 10-layer models suggest that “bedrock” motions were elevated due in part to the wide-angle reflection of S energy from the base of a relatively thin (25 km) continental crust in the region. Characteristics of geologic and geotechnical units as currently mapped for the San Francisco Bay region show that average ratios of peak horizontal acceleration, velocity and displacement increase with decreasing mean shear-wave velocity. Ratios of peak acceleration for sites on “soil” (alluvium, fill/Bay mud) are statistically larger than those for sites on “hard rock” (sandstone, shale, Franciscan Complex). Spectral ratios establish the existence of predominant site periods with peak amplifications near 15 for potentially damaging levels of ground motion at some sites underlain by alluvium and fill/bay mud. Average spectral amplifications inferred for vertical and the mean horizontal motion are, respectively, (1,1) for sites on the Franciscan Complex (KJf), (1.4, 1.5) for sites on Mesozoic and Tertiary rocks (TMzs), (2.1, 2.0) for sites on the Santa Clara Formation (QTs), (2.3, 2.9) for sites on alluvium (Qal), and (2.1, 4.0) for sites on fill/Bay mud (Qaf/Qhbm). These mean values are not statistically different at the 5% significance level from those inferred from previous low-strain data. Analyses suggest that soil amplification and reflected crustal shear energy were major contributors to levels of ground motion sufficient to cause damage to vulnerable structures at distances near 100 km in the cities of San Francisco and Oakland.
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Salas-Reyes, Antonio E., Ignacio Mejía y José M. Cabrera. "Effect of Ti Microaddition on Cavitation Behavior During Uniaxial Hot-Tensile of Fe-22Mn-1.5Al-1.3Si-0.5C Austenitic TWIP Steel". MRS Proceedings 1812 (2016): 123–28. http://dx.doi.org/10.1557/opl.2016.28.
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ABSTRACTIt is well-known that metal and alloys develop internal cavities when subjected to uniaxial or multiaxial tensile strains at elevated temperature. In most cases, cavitation may lead to premature failure during forming. Therefore, damage and fracture behavior imposes significant limitations in hot metal-forming processes. Although high-Mn austenitic TWIP steels exhibit a unique combination of strength and ductility, cavitation during hot working is one issue that must be tackled. The aim of this research work is to determine the effect of Ti microaddition on cavity mechanisms of Fe-22Mn-1.5Al-1.3Si-0.5C TWIP steel under uniaxial hot-tensile condition at 800 °C and constant true strain rate of 10-3 s-1. For this purpose, light optical (LOM) and scanning electron (SEM) microscopies and image analysis were applied to quantify cavities formation along longitudinal section of deformed samples near to the fracture surface. The number of cavities greater than 10 µm (critical length) in non-microalloyed and Ti microalloyed TWIP steels were 2.75 and 3.75 cavities/mm2, respectively. On the other hand, average cavity area was 125 and 152 µm2, respectively. Both TWIP steels showed cavities type “r”, “l” and “A”. Finally, Ti microaddition to TWIP steel resulted in a predominant brittle fracture behavior due to finer grain-boundary precipitation, which weakens grains cohesion and accelerates crack growth by grain-boundary sliding. In this case, crack growth behavior is explained in terms of a void interconnection mechanism.
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Ford, E. A. K., A. L. Aruliah, E. M. Griffin y I. McWhirter. "High time resolution measurements of the thermosphere from Fabry-Perot Interferometer measurements of atomic oxygen". Annales Geophysicae 25, n.º 6 (29 de junio de 2007): 1269–78. http://dx.doi.org/10.5194/angeo-25-1269-2007.
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Abstract. Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers (FPIs) to be performed. 10-s integration times were used during a campaign in April 2004 on an FPI located in northern Sweden in the auroral oval. The FPI is used to study the thermosphere by measuring the oxygen red line emission at 630.0 nm, which emits at an altitude of approximately 240 km. Previous time resolutions have been 4 min at best, due to the cycle of look directions normally observed. By using 10 s rather than 40 s integration times, and by limiting the number of full cycles in a night, high resolution measurements down to 15 s were achievable. This has allowed the maximum variability of the thermospheric winds and temperatures, and 630.0 nm emission intensities, at approximately 240 km, to be determined as a few minutes. This is a significantly greater variability than the often assumed value of 1 h or more. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with waves with short periods. Gravity waves are an important feature of mesosphere-lower thermosphere (MLT) dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. At high latitudes gravity waves may be generated in-situ by localised auroral activity. Short period waves were detected in all four clear nights when this experiment was performed, in 630.0 nm intensities and thermospheric winds and temperatures. Waves with many periodicities were observed, from periods of several hours, down to 14 min. These waves were seen in all parameters over several nights, implying that this variability is a typical property of the thermosphere.
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Field, E. H., K. H. Jacob y S. E. Hough. "Earthquake site response estimation: A weak-motion case study". Bulletin of the Seismological Society of America 82, n.º 6 (1 de diciembre de 1992): 2283–307. http://dx.doi.org/10.1785/bssa0820062283.
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Abstract Using weak-motion recordings of aftershocks of the 1989 Loma Prieta earthquake recorded in Oakland, California, near the failed Nimitz Freeway, two methods have been applied to estimate the site response of an alluvium site and three mud-over-alluvium sites. The first estimate is the traditional spectral ratio, and the second utilizes the cross spectrum. Recordings obtained at a nearby bedrock site are used as estimates of the sediment site input motions. While the two site response estimates produce similar peaks and troughs, there is an approximate factor of 2 difference in amplitudes. This discrepancy is evidence that there is a much greater level of noise than would be expected from the pre-event ambient noise. We interpret this as signal-generated noise produced by scattering from heterogeneities, which causes the true sediment site input to differ significantly from the bedrock site recording. Given this level of noise, the cross-spectrum estimate suffers a severe downward bias (by a factor of 2 in this study) and should probably not be used when the input motion is estimated from a bedrock site recording. The spectral-ratio estimates are relatively unbiased, but the level of noise introduces a large degree of uncertainty. Therefore, inferences about site response from individual spectral ratios should probably be avoided. On the other hand, ensemble averages of the estimates significantly reduce the scatter to reveal resonances that agree quite well in frequency and overall shape with those of one-dimensional models whose parameters were determined independently. A discrepancy of higher observed amplitudes than predicted by theory remains unexplained but most likely results from the effects of boundary layer topography, which are not accounted for by the simple one-dimensional models.