699 research outputs found
Trails and Physical Activity: A Review
To provide a synthesis of research on trails and physical activity from the public health, leisure sciences, urban planning, and transportation literatures. Methods: A search of databases was conducted to identify studies published between 1980 and 2008. Results: 52 studies were identified. The majority were cross-sectional (92*%) and published after 1999 (11%). The evidence for the effects of trails on physical activity was mixed among 3 intervention and 5 correlational studies. Correlates of trail use were examined in 13 studies. Several demographic (eg, race, education, income) and environmental factors (eg, land-use mix and distance to trail) were related to trail use. Evidence from 31 descriptive studies identified several facilitators and barriers to trail use. Economic studies (n = 5) examining trails in terms of health or recreational outcomes found trails are cost-effective and produce significant economic benefits. Conclusion: There is a growing btidy of evidence demonstrating important factors that should be considered in promoting trail use, yet the evidence for positive effects of trails on physical activity is limited. Further research is needed to evaluate the effects of trails on physical activity. In addition, trail studies that include children and youth, older adults, and racial and ethnic minorities are a research priority
A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter
A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the short- and long-term time- dependent response of the material. These two contributions can be related to physical processes: water flow through the tissue and dissipative characteristics of the collagen fibers, respectively. An accurate agreement of the model with the mean tension and kinematic response of amnion in uniaxial relaxation tests was achieved. By variation of a single linear factor that accounts for the variability among tissue samples, the model provides very sound predictions not only of the uniaxial relaxation but also of the uniaxial creep and strip-biaxial relaxation behavior of individual samples. This suggests that a wide range of viscoelastic behaviors due to patient-specific variations in tissue composition
Sailing into a dilemma : an economic and legal analysis of an EU trading scheme for maritime emissions
On the basis of a joint economic and legal analysis, we evaluate the effects of a “regional” (European)
emission trading scheme aiming at reducing emissions of international shipping. The focus lies on the
question which share of emissions from maritime transport activities to and from the EU can and
should be included in such a system. Our findings suggest that the attempt to implement an EU
maritime ETS runs into a dilemma. It is not possible to design a system that achieves emission
reductions in a cost efficient manner and is compatible with international law
Fish passage design for sustainable hydropower in the temperate Southern Hemisphere:An evidence review
1U Chassis Accepts PCIe or PXIe Cards
PCIe and PXIe are both open-standards for expansion and I/O cards, both enabling the end user of the system to configure the desired I/O to suit their needs. The problem is that the two cards are not space-compatible, requiring systems manufacturers to create two separate product to address both markets. This article discloses a means that allows for a flexible architecture that can accept either a PCIe bay or a PXIe bay, thus enabling both types of I/O, PCIe and PXIe, to be supported in a common-design, and in this example, a system that can be mounted in a standard 19” rack that consumes only 1U of rack space
Optimization of a novel, wide-field, high resolution optical microscopy system
Knowledge of the complex fiber structures of soft tissues can lead to greater understanding of basic structure-function relationships and potentially to improvements in tissue engineered constructs and micro-repair techniques. Imaging these structures in fresh, whole-tissue samples is difficult,mainly because current microscopes are designed for small-scale, narrow field imaging of thin, slide-mounted specimens. Several precision stage motaging systems like the CoolScopeTM whole slide scanner (Nikon, Inc.), Scanscope XT(Aperio, Inc.) are available but they are only capable of single mode imaging, are often time consuming and can be prohibitively expensive for a small research
laboratory. The goal of this project was to develop a high speed, high
resolution imaging system at low cost - capable of imaging thicker, fresh tissue samples as well as prepared slides using both, normal and polarized light
Herd specific risk factors for Mycoplasma hyopneumoniae infections in suckling pigs at the age of weaning
BACKGROUND
Mycoplasma hyopneumoniae is the etiologic agent of enzootic pneumonia mainly occurring in fattening pigs. It is assumed that horizontal transmission of the pathogen during nursery and growing phase starts with few suckling pigs vertically infected by the sow. The aim of the present study was the exploration of the herd prevalence of M. hyopneumoniae infections in suckling pigs followed by an investigation of various herd specific factors for their potential of influencing the occurrence of this pathogen at the age of weaning.
RESULTS
In this cross-sectional study, 125 breeding herds were examined by taking nasal swabs from 20 suckling pigs in each herd. In total, 3.9% (98/2500) of all nasal swabs were tested positive for M. hyopneumoniae by real-time PCR. Piglets tested positive originated from 46 different herds resulting in an overall herd prevalence of 36.8% (46/125) for M. hyopneumoniae infection in pigs at the age of weaning. While the herds were epidemiologically characterized, the risk for demonstration of M. hyopneumoniae was significantly increased, when the number of purchased gilts per year was more than 120 (OR: 5.8), and when the number of farrowing pens per compartment was higher than 16 (OR: 3.3). In herds with a planned and segregated production, where groups of sows entered previously emptied farrowing units, the risk for demonstration of M. hyopneumoniae in piglets was higher in herds with two or four weeks between batches than in herds with one or three weeks between batches (OR: 2.7).
CONCLUSIONS
In this cross-sectional study, several risk factors could be identified enhancing the probability of breeding herds to raise suckling pigs already infected with M. hyopneumoniae at the time of weaning. Interestingly, some factors (farrowing rhythm, gilt acclimatisation issues) were overlapping with those also influencing the seroprevalences among sows or the transmission of the pathogen between older age groups. Taking the multifactorial character of enzootic pneumonia into account, the results of this study substantiate that a comprehensive herd specific prevention programme is a prerequisite to reduce transmission of and disease caused by M. hyopneumoniae
Introduction of a portable ultrasound unit into the health services of the Lugufu refugee camp, Kigoma District, Tanzania
Herd specific risk factors for Mycoplasma hyopneumoniae infections in suckling pigs at the age of weaning
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