Academic literature on the topic 'Sfsts'

A silk-based small-caliber tubular scaffold (SFTS), which is fabricated using a regenerated silk fibroin porous scaffold embedding a silk fabric core layer, has been proved to possess good cell compatibility and mechanical properties in vitro. In this study, the endothelialization ability and the steady-state blood flow of SFTSs were evaluated in vivo by implanting and replacing a common carotid artery in a rabbit. The results of the color doppler ultrasound and angiographies showed that the blood flow was circulated in the grafts without aneurysmal dilations or significant stenoses at any time point, and ran stronger and close to the autologous blood vessel from one month after implantation. The SFTSs presented an initial tridimensionality without being distorted or squashed. SEM and immunohistochemistry results showed that a clear and discontinuous endodermis appeared after one month of implantation; when implanted for three months, an endothelial layer fully covered the inner surface of SFTSs. RT-PCR results indicated that the gene expression level of CD31 in SFTSs was 45.8% and 75.3% by that of autologous blood vessels at 3 months and 12 months, respectively. The VEGF gene showed a high expression level that continued to increase after implantation.

A silk fibroin tubular scaffold (SFTS) has been designed and fabricated using silk fabric and regenerated silk fibroin, and used in the construction of artificial blood vessels. As a replacement for blood vessels, scaffolds should have a suitable interface for the adherence and proliferation of vascular cells, and the pore structure of the internal surface is one of most important factors. In this article, we investigate the effect of SFTSs with different pore structures on cells growth. Pore structures were controlled by adjusting the concentration of both the silk fibroin and the polyethylene glycol diglycidyl ether cross-linker as well as the freezing temperature. Intuitive cell fluorescence imaging and MTT assays on fibroblasts and human umbilical vein endothelial cells (HUVEC) were used to probe interactions with internal surfaces of differing pore diameter and density. The results showed that SFTSs fabricated under different conditions exhibited no cytotoxicity. Furthermore, fibroblasts were highly migratory, occupied the interface and could bridge the macropores well when the pore diameter was 50 ∼ 75 µm. SFTSs with micropores of about 30 ∼ 50 µm in diameter were deemed suitable for the growth and proliferation of HUVECs.

AbstractResearch on short food supply chains (SFSCs) has experienced a remarkable growth during recent years, offering ample evidence that the creation of such alternative food distribution networks can bring multiple benefits to both farmers and consumers. Nevertheless, farmers' engagement in SFSCs is still limited in many countries. Two studies designed to illustrate the role of competencies in the development of SFSCs are reported in this paper. The first one assessed the influence of farmers' self-perceived competencies on their willingness to participate in SFSCs. The second examined whether the engagement in SFSCs affects the levels of participants' competency needs. Study 1 revealed that willingness to participate in SFSCs is affected by the levels of farmers' competencies on issues pertaining to management, entrepreneurship, marketing, networking and cooperation. Although other factors such as farmers' citizenship behavior, their environmental concern and the perception that engagement in SFSCs can increase farm income are also associated with this willingness, self-perceived competencies represent the most important set of predictors. Study 2 uncovered that participation in SFSCs increases farmers' needs in all the above-mentioned categories of competencies. Taken together, these results indicate that farmers' competencies significantly affect their involvement in SFSCs, and that engagement in SFSCs augments competency needs, thus highlighting the importance of creating spaces that help farmers develop and exploit new capabilities.

Abstract Introduction Many European schools implement smoke-free school policies (SFSPs). SFSPs may decrease adolescent smoking by causing adolescents to perceive stronger antismoking norms, yet there exists no quantitative evidence that indicates for which norms and for whom such effects may occur. This study therefore assessed to what extent adolescents’ perceived antismoking norms among best friends, teachers, and society at large were associated with SFSPs, and whether these associations were moderated by adolescents’ level of school connectedness. Aims and Methods Survey data were collected in 2016/2017 on 10,653 adolescents aged 14–16 years old and 315 staff members in 55 schools from seven European cities. Associations of adolescent-perceived SFSPs and staff-reported SFSPs with best friend, teacher, and societal antismoking norms were estimated in multilevel logistic regression models, adjusted for demographics and school-level smoking prevalence. We tested for interaction between school connectedness and SFSPs. Results Adolescent-perceived SFSPs were positively associated with antismoking norms by teachers (odds ratio [OR]: 1.46, 95% confidence interval [CI]: 1.15–1.85), were negatively associated with antismoking norms by best friends (OR: 0.81, 95% CI: 0.67–0.99), but were not significantly associated with antismoking norms by society at large (OR: 0.87, 95% CI: 0.74–1.02). All interaction tests between adolescent-perceived SFSPs and school connectedness were nonsignificant. Staff-reported SFSPs were not associated with any norm and showed no significant interaction with school connectedness. Conclusions We found that SFSPs are associated with adolescents’ perception of more antismoking norms by teachers, but less antismoking norms by best friends, irrespective of adolescents’ level of school connectedness. Implications Smoke-free school policies, just as many other tobacco control policies, are assumed to foster adolescents’ perception of antismoking norms. Still, current evidence does not demonstrate which antismoking norms may be influenced by SFSPs and whether this influence is equal for adolescents with different levels of school connectedness. This study suggests that SFSPs foster adolescents’ perception of antismoking norms by teachers, but may concurrently lead to the perception of less antismoking norms by best friends, irrespective of adolescents’ school connectedness. SFSPs may therefore need to be complemented with interventions that target antismoking norms in adolescent peer groups.

The interest in short food supply chains (SFSCs) has grown significantly in the last decade, notably in respect of their potential role to achieve more sustainable food chains. However, a major barrier to achieving sustainable supply chains is the uncertainty associated with supply chain activities. Therefore, this paper aims to explore the different resilience capabilities that SFSCs possess and the potential role of digital technologies as enablers of SFSCs’ resilience. Using a case study research approach, semi-structured interviews were conducted in two SFSCs in Mexico. Collected data were analyzed using thematic analysis. Findings suggest that SFSCs possess the supply chain resilience (SC resilience) capabilities investigated here, namely flexibility, redundancy, collaboration, visibility and agility. A key finding is the importance of low-cost digital technologies (including freeware and social media) that can support flexibility, collaboration, visibility and agility. These findings raise important implications for SFSCs actors exploring opportunities to improve their collective resilience. This study expands the current literature by proposing a conceptual framework that summarizes a wide variety of strategies that support SC resilience capabilities in the context of SFSCs.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a new virus (SFTS virus) reported to be endemic to central and northeastern parts of China. SFTS virus, which is classified into the genus Phlebovirus (the Bunyaviridae family), is suspected to be a tick-borne virus owing to evidence in two species of ticks: Haemaphysalis longicornis and Rhipicephalus microplus. SFTS virus is detected among many species of domestic animals in China. The clinical symptoms of SFTS include fever, thrombocytopenia, leucocytopenia, gastrointestinal symptoms, neural symptoms, bleeding tendency. The fatality rate of SFTS is 6-30%. Person-to-person transmission of SFTS virus is possible through blood contact. Clinical and epidemiological studies of SFTS, the cases of SFTS outside China, person-to-person transmission of SFTS virus, evolutionary and molecular analysis of the emergent SFTS virus, and risk assessment of human infection with a novel phlebovirus are considered in this review.

While the interest in Short Food Supply Chains (SFSCs) is growing, we still await management studies that explore the impact of stakeholders of SFSCs in substantial numbers. This article investigates the differences in the business models of SFSCs that may be attributed to the initiator-stakeholder, interacting with other stakeholders. Essential to business models are the value proposition, value creation and value capture, but it is the ambition of the initiator-stakeholder that starts a SFSC. Initiator-stakeholders of 57 SFSCs were interviewed on a combination of both multiple choice and open questions. The data converges on three categories of business models. First and foremost, a large majority of SFSCs is driven by the aim of the initiator-stakeholder to increase economic viability, uses the market as governance structure, resulting in profit margins likely to be above margins in conventional business. Two other categories of business models of SFSCs group around the theme of producer-support, and, producer-consumer interaction, respectively.

Recently there has been an increase in awareness of the role of drugs other than alcohol in the causation of road accidents and deaths, with the most recent report indicating that 33% of all Victorian (Australia) road fatalities are drug (other than alcohol) related (TAC, 2006). Currently in Victoria, one of the classes of drugs reported to be of most concern is the amphetamines. The epidemiological driving literature highlights a possible association between amphetamine use and road crashes. However, since the cognitive research generally indicates cognitive enhancing properties following amphetamine consumption, it remains unclear how amphetamines may be related to adverse driving. The present thesis was designed to explore this issue. In response to the increasing number of drug-related road fatalities, the Standardised Field Sobriety Tests (SFSTs), designed and validated for the detection and assessment of impairment associated with alcohol intoxication, are currently being employed by the Victoria Police (Australia) for the identification of driving impairment associated with drugs other than alcohol. The present thesis was designed to evaluate whether the SFSTs are a sensitive measure for identifying impairment associated with a single acute therapeutic amphetamine dose. Furthermore, the accuracy of using the SFSTs to detect driving impairment associated with these amphetamine doses was also evaluated. The present thesis examined the effects of a single acute therapeutic dose of various amphetamine preparations, on simulated driving performance, driving-related cognitive processes (assessed using standard cognitive tasks and the electroencephalogram [EEG]), and performance on the SFSTs, in healthy, stimulant-using, non-fatigued adults. The present thesis consisted of five separate experiments. The first three experiments examined the effects of d-amphetamine, d,l-methamphetamine, and d-methamphetamine, on simulated driving performance, driving-related cognitive processes, and performance on the SFSTs. Experiment 4 and Experiment 5 assessed the effects of d-amphetamine and dmethamphetamine on visual and auditory cognitive processes using the EEG. These forms of amphetamines were selected as they are commonly used recreationally by young adult drivers, and occupationally by truck drivers. Experiment 1, Experiment 2, and Experiment 3 employed a repeated-measures, counterbalanced, double blind, placebo-controlled design. In each experiment, twenty different (i.e. 60 participants in total) healthy volunteers (10 males and 10 females) completed two treatment conditions i) placebo and ii) 0.42mg/kg amphetamine (~30mg). Driving performance was assessed using a driving simulator task, which consisted of four driving tasks; �freeway traffic driving� and �city traffic driving� in both day and night conditions. Cognitive performance was assessed using a range of computer and pen and paper tasks designed to assess attention, psychomotor performance, and perceptual speed. Specifically, the tasks were: the Digit Span Test; a Digit Vigilance task; a Movement Estimation Task; the Digit Symbol Substitution Test; a Tracking Task; the Trail-Making Test; and the Inspection Time task. SFSTs performance was assessed using the Horizontal Gaze Nystagmus (HGN) test, the Walk and Turn (WAT) test, and the One Leg Stand (OLS) test. Three blood and saliva samples were obtained throughout all experimental sessions (120, 170, and 240 minutes after drug administration). The results indicated that 0.42mg/kg d-amphetamine significantly impaired simulated driving performance, in recreational stimulant users, 2-3 hours post-drug administration, when mean blood amphetamine concentrations were approximately 90ng/mL. No significant driving decrements were observed following d,l-methamphetamine or dmethamphetamine, when methamphetamine blood concentrations were 90ng/mL and 70ng/mL, respectively. There were only few driving behaviours that were found to be significantly reduced with d-amphetamine, such as reductions in signalling adherence and driving too fast for the traffic conditions. However, during all three amphetamine conditions, drivers travelled at a slower speed on the freeway at the time that an emergency situation occurred, relative to the placebo condition. It was argued that either this may result from more cautious driving, or that the reduction in speed acted as a compensatory mechanism to permit drivers to attend to other aspects of driving. Overall, the present results indicate that a therapeutic dose of amphetamine does not produce considerable impairment to driving, as only minimal amphetamine effects were observed on driving performance. In terms of cognitive performance, the results indicated that a therapeutic dose of various amphetamines has minimal effect on driving-related cognitive functioning, with some significant improvements noted in aspects of attention, psychomotor functioning and perceptual speed. This is consistent with the failure to identify significant driving impairments, described above, following a similar dose. However, the ability to perceive and predict motion and estimate �time to contact�, assessed using a movement estimation task, was affected following d-amphetamine and d-methamphetamine consumption. In terms of performance on the SFSTs, the present thesis demonstrated that following the administration of low-level d-amphetamine, d,l-methamphetamine, and dmethamphetamine, performance on the SFSTs was not impaired. Using the SFSTs, impairment associated with low dose d-amphetamine was identified in only 5% of cases, dmethamphetamine in 5% of cases, and d,l-methamphetamine in 0% of cases. These findings indicate that the degree of impairment produced with the low amphetamine dosing conditions was below the threshold of sensitivity of the SFSTs. However, as significant impairments in driving were not observed with amphetamines, the present SFSTs findings highlight that these tests are unlikely to produce false positive results during police drug evaluation procedures for amphetamine-related impairments. Experiment 4 and Experiment 5 similarly employed a repeated-measures, counterbalanced, double blind, placebo-controlled design. In each experiment, twenty healthy volunteers (10 males and 10 females) completed two treatment conditions i) placebo and ii) 0.42mg/kg amphetamine (~30mg). Tasks designed to assess visual and auditory cognitive functions relevant to driving were administered. Specifically, these processes were: divergent visual system pathways (magnocellular and parvocellular pathways); aspects of visual field processing (central and peripheral visual fields); mismatch negativity (MMN); prepulse inhibition (PPI); selective attention; resource allocation; and speed of processing. Two blood and saliva samples were obtained throughout all experimental session (120 and 200 minutes after drug administration). d-amphetamine and d-methamphetamine generally improved cognitive functioning, as assessed with visual and auditory ERP indices. Specifically, the results demonstrated that a low-level acute dose of d-amphetamine and d-methamphetamine improved early processing of visual information (indexed by improvements to the P100 component for the magnocellular and parvocellular visual pathways). In addition, d-methamphetamine improved the speed at which visual information was evaluated and processed (indexed by decreases in P300 latency), which was consistent with d-methamphetamine-related improvements in reaction time. There was a trend for d-amphetamine to improve the speed that changes in auditory stimulation were automatically detected (indexed by decreases in MMN latency). In addition, d-methamphetamine improved the ability to automatically �screen out� irrelevant and intrusive auditory information (indexed by increases in PPI of the startle response). d-amphetamine was found to improve the speed at which auditory information was evaluated and processed (indexed by decreases in P300 latency), which was substantiated with corresponding improvements in reaction time and accuracy. Although amphetamines were generally shown to enhance ERP indices, a trend was found for d-amphetamine to differentially affect different regions of the visual field, in terms of selective attention. Specifically, there was a trend-level indication that d-amphetamine improved indices of selective attention (denoted by increases in N200 amplitude) for information presented centrally, but impaired indices of selective attention (denoted by decreases in N200 amplitude) for information presented in the periphery. Although impairments to the peripheral visual field were not similarly observed with dmethamphetamine, decrements to indices of selective attention (denoted by decreases in N200 amplitude) were also found with d-methamphetamine during the auditory oddball task. In terms of driving, these results suggest that drivers dosed with low-level amphetamine may not selectively attend to and discriminate changes within the traffic environment, although further research is required to confirm this. In conclusion, the present thesis has demonstrated that a single acute therapeutic dose of amphetamine produces minimal and inconsistent effects to driving. However, some (inconsistent) evidence was found that suggests that there may be mild impairments such as decreased ability to perceive and predict motion, tunnel vision effects, and decrements to selective attention. In addition, the present thesis highlights that at therapeutic doses, amphetamines do not impair SFSTs performance, which is in accordance with the failure to identify substantive amphetamine-related decrements to driving and cognitive functioning observed in the present thesis.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV
SFSS is a universal, small, and low cost, functionally redundant flight termination system (FTS) that incorporates encoding, processing and TSPI capabilities, provides critical health/safety/welfare monitoring and allows for highly efficient telemetering of weapon application and FTS data. The SFSS is intended as a solution to provide weapon system developers, test agencies, and range safety officers the ability to track, monitor, and if necessary, terminate all types of weapon systems. The SFSS components are intended to significantly reduce the recurring costs and improve the quality of test support by minimizing physical intrusion into weapon systems, and potentially eliminating the need for warhead removal. In addition, a common hardware suite assists in reducing the overall system cost of acquisition, a key element in today's world of stressed budgets. The SFSS is designed to interface with newly developed weapon systems, while providing the capability to be integrated into existing weapon systems with nominal modifications to the platform. The SFSS development is a multi-disciplinary effort, whose participating organizations include industry suppliers, range and system safety representatives, and technical offices from all branches of the armed services, as well as the weapons vendors to ensure that applicable technical and regulatory requirements are met. The original requirements for the project were defined within the SFSS System Performance Specification (SPS), which has undergone a number of updates as the design effort has progressed from concept to assembly and debug of the prototype components. This paper will provide an overview of the overall program status, key features of the SFSS including features added during development, critical design challenges, and additional activities planned to enhance the functionality of the system.

Gli scenari agricoli europei rivelano un crescente interesse per le filiere corte come strumento di promozione dei sistemi alimentari locali. Nonostante i piccoli agricoltori siano la spina dorsale dell'agricoltura europea, gli interventi politici e legislativi che si sono susseguiti nei decenni non hanno sufficientemente tutelato ne promosso la loro attuale posizione in ambito socio-economico. Il presente lavoro mira a fornire un'approfondita analisi del ruolo delle filiere corte all'interno del quadro normativo europeo per comprendere se l’attuale legislazione sostiene o piuttosto inibisce questi sistemi alternativi di produzione e distribuzione alimentare. Muovendo dall'esame della pletora di definizioni attribuite alla filiera corta e soffermandosi su una revisione critica delle più significative riforme della PAC, in particolare alla luce della strategia 'Farm to Fork', vengono identificate nuove priorità che appaiono più favorevoli ai piccoli agricoltori. Lo studio è arrichito da un confronto tra l'approccio adottoato dell'UE - caratterizzato principalmente da strumenti di hard law e misure top-down -, e quello della California ‘socialmente auto-regolato’, in cui gli 'Alternative Food Movements' e le strategie bottom-up sono attori principali nella regolamentazione della filiere corte e del loro impatto sulla comunità. Lo scopo finale é quello di identificare potenziali elementi utili che, se adottati, potrebbero migliorare il modello europeo.
European agricultural landscapes are undergoing fundamental changes, revealing an increasing interest in Short Food Supply Chains as a tool to promote local food systems and products. Despite small farmers are the backbone of agriculture in the EU, both policy leadership and legal interventions have been not sufficiently fostering their position in the socio and economic today’s narrative. The study aims at providing an extensive analysis of the role of SFSCs within the EU legal framework to understand whether EU legislation supports or rather inhibits these alternative systems of production and supply. Moving from the examination of the plethora of SFSC definitions to a critical revision of the most significant CAP reforms, especially in the light of the ‘Farm to Fork’ strategy, new priorities that seem more favorable to small farmers are identified. The study is enriched by a comparison between the EU legal approach - mainly characterized by hard law instruments and top-down measures -, and the Californian ‘socially self-regulated’ approach, where Alternative Food Movements and bottom-up strategies act as the main player in regulating SFSCs and their impact on the community with the aim of identifying potential insights that could improve the EU model.

This paper presents an investigation of a novel linear-type piezoelectric ultrasonic actuator for application in a Smart Fuze Safety System (SFSS). Based on the requirements of SFSS, the structural parameters of the proposed piezoelectric ultrasonic actuator are determined by fuze arming mode. Moreover, sensitivity analysis of the structural parameters to the frequency consistency is conducted using FEM software, after which the optimal dimensions are obtained with two close natural vibration frequencies. To validate the results of FEM, the frequency sweep tests of the piezoelectric ultrasonic actuator are performed to determine the motor’s actual working mode frequencies with PSV-300-B Doppler laser vibrometer system. Furthermore, the results of frequency sweep test are compared with that of the finite element analysis, and further verified by impedance analyzer. To investigate the overall performance of the piezoelectric ultrasonic actuator, vibration modes of actuator’s stator, output speed and force of the piezoelectric ultrasonic actuator are tested. The experimental results show that the output speed and force of the actuator can reach 88.2 mm/s and 2.3N respectively, which means that piezoelectric ultrasonic actuator designed in this paper can meet the demands of the SFSS.

Abstract Submerged floating tunnel (SFT) concept has been studied by many researchers as an alternative of conventional or floating bridges, especially in the fjord or as a connection between island and land. One of the major challenges is large dynamic responses under extreme wave and earthquake excitations. In this regard, two different types of SFT, which are mono and dual SFTs, are suggested in this study, and the global performance of them is compared through tunnel-mooring fully-coupled time-domain numerical simulations. The tunnel and mooring lines are modeled by the lumped-mass-based line model. The Morison equation is utilized for hydrodynamic load estimations of the tunnel and mooring lines at their instantaneous positions. To check dynamic response of SFT under operating condition, 10-yr waves with the current are considered as an environmental condition. Dynamic responses, mooring tensions, and inertial and drag forces are systematically compared.

Due to the growing shortage of donor livers, more patients are waiting for liver transplantation. Efforts to expand the donor pool include the use of living donor liver transplantation (LDLT) and split liver transplantation. LDLT involves a healthy person undergoing a partial hepatectomy to donate a part of his liver to a patient with severe liver failure. Afterwards, the regenerative capacity of the organ allows the livers of both donor and recipient to regrow to normal liver masses. The procedure is not without risk as serious complications may occur (such as cholestasis, ascites, gastrointestinal bleeding and renal impairment). An inadequate liver mass compared to the body mass may result in the small-for-size syndrome (SFSS). In both donor and recipient, LDLT may lead to portal hypertension associated with the elevated intrahepatic resistance of a smaller liver, and an increased portal venous (PV) inflow per gram of liver tissue compared to the total liver before resection. Excessive hyperperfusion and shear stress may damage the sinusoidal endothelial cells and lead to graft dysfunction.

This paper presents potential application of waste heat recovery (WHR) systems in high-temperature reactors technology. WHR systems have attracted the attention of many researchers over the past two decades, as using waste heat improves the system overall efficiency, notwithstanding the additional cost to upgrade the plant efficiency. WHR systems require specially designed heat recovery equipment, and as such the high-temperature gas-cooled reactor used and/or spent fuel tanks (SFTs) were considered by the way of example. An appropriately scaled system was designed and modelled to demonstrate the functioning of such a system, by the way of a cooling process of the used and/or SFT. Two separate and independent cooling lines, using a natural circulation flow in a particular form of heat pipes called thermosyphon loops were used to ensure that the fuel tank (FT) is cooled when the power conversion unit has to be switched off for maintenance, or if it fails. Assuming a one-dimensional flow model, a quasi-static and incompressible flow of both liquid and vapour, a theoretical model that simulates the heat transfer process in the as-designed WHR system is developed in this paper.