710 research outputs found
Perceptions of Safety by On-Campus Location, Rurality, and Type of Security/Police Force: The Case of the Community College
This study examined Virginia community college students\u27 perceptions of campus safety. A survey of 11,161 students revealed the crimes students most feared being a victim of while on the community college campus and the areas in which they felt the most and least safe. The research also demonstrated the effect of certain variables had on students\u27 overall perception of campus safety. The variables studied included student demographics, the presence and type of security personnel, and the rurality of the campus setting. The campuses with the highest and lowest degrees of perceived safety were then further studied via case studies to gather detailed information, which may assist college administrators and policymakers in improving campus safety on community college campuses
Comparing population estimates for drug users, the prevalence of blood-borne viruses and the provision of services in one London borough: Evidence of a gap in provision?
Accuracy of Wrist-worn Physical Activity Monitors to Measure Energy Expenditure
IIn recent years, the popularity and demand of physical activity monitors has drastically risen with the need and want to improve physical fitness. Newer devices worn on the wrist measure both heart rate and energy expenditure but the accuracy of these measurements is unclear. PURPOSE: To measure the accuracy of three separate wrist-worn activity monitors to estimate energy expenditure during structured periods of aerobic exercise. METHODS: Twelve men and three women (22 ± 3 years, 25 ± 3 kg/m2) consented to participate in this study. Three different physical activity monitors, TomTom Cardio (TT), Microsoft Band (MB), and Fitbit Surge (FB), were randomly assigned to either the left or right wrist of each participant. The instructions for the testing procedure were thoroughly explained to every participant at the start of each trial. The treadmill started at a speed of 2 mph and increased by 1 mph every three minutes up to a max speed of 6 mph. Energy expenditure was estimated through direct measurement of oxygen consumed and carbon dioxide produced through a metabolic cart (MC, Parvo Medics True One ®2400). The mean bias in energy expenditure between MC and each device was calculated. Pearson product-moment correlations and 95% equivalence testing were also calculated. Statistical significance was set at an alpha level of 0.05. RESULTS: The mean bias between the MC and devices at 2 mph varied from -1.9 ± 1.1 kcal/min (FB) to 0.7 ± 1.0 kcal/min (MB) while the mean bias at 6 mph varied from -1.7 ± 2.1 kcal/min (MB) to 5.2 ± 1.7 kcal/min (TT). For total energy expenditure, all devices were significantly correlated with the MC (FB: r=0.66, p=0.007; TomTom: r=0.77, p\u3c0.001; MB: r=0.59, p=0.02). The mean bias for total energy expenditure was -25 ± 16 kcal for the FB, 26 ± 13 kcal for the TT, and -11 ± 17 kcal for the MB. The equivalence zone for MC was 88 kcal to 108 kcal but 90% confidence intervals of devices did not fall within this zone. CONCLUSION: The wrist-worn physical activity monitors used in this study that measure heart rate and energy expenditure tend to either underestimate or overestimate total energy expenditure from treadmill walking and running
Contralateral Total Hip Arthroplasty After Hindquarter Amputation
We describe the management and outcome of a 62-year old lady who developed severe osteoarthritis of the hip, nine years after a hindquarter amputation for radiation-induced sarcoma of the contralateral pelvis. The difficulties of stabilising the pelvis intraoperatively and the problems of postoperative rehabilitation are outlined. The operation successfully relieved her pain and restored limited mobility
Lunar hand tools
Tools useful for operations and maintenance tasks on the lunar surface were determined and designed. Primary constraints are the lunar environment, the astronaut's space suit and the strength limits of the astronaut on the moon. A multipurpose rotary motion tool and a collapsible tool carrier were designed. For the rotary tool, a brushless motor and controls were specified, a material for the housing was chosen, bearings and lubrication were recommended and a planetary reduction gear attachment was designed. The tool carrier was designed primarily for ease of access to the tools and fasteners. A material was selected and structural analysis was performed on the carrier. Recommendations were made about the limitations of human performance and about possible attachments to the torque driver
Temporal pattern of africanization in a feral honeybee population from Texas inferred from mitochondrial DNA
The invasion of Africanized honeybees (Apis mellifera L.) in the Americas provides a window of opportunity
to study the dynamics of secondary contact of subspecies of bees that evolved in allopatry in ecologically distinctive
habitats of the Old World. We report here the results of an 11-year mitochondrial DNA survey of a feral honeybee
population from southern United States (Texas). The mitochondrial haplotype (mitotype) frequencies changed radically
during the 11-year study period. Prior to immigration of Africanized honeybees, the resident population was essentially
of eastern and western European maternal ancestry. Three years after detection of the first Africanized swarm there
was a mitotype turnover in the population from predominantly eastern European to predominantly A. m. scutellata
(ancestor of Africanized honeybees). This remarkable change in the mitotype composition coincided with arrival of
the parasitic mite Varroa destructor, which was likely responsible for severe losses experienced by colonies of European
ancestry. From 1997 onward the population stabilized with most colonies of A. m. scutellata maternal origin.PRODEP II - Medida 5/Acção 5.
Identification of africanized honey bee (Hymenoptera: apidae) mitochondrial DNA: validation of a rapid polymerase chain reaction-based assay
Polymerase chain reaction (PCR)-ampliÞed mitochondrialDNA(mtDNA)assays have
been used in studies of the Africanization process in neotropical feral and managed honey bee
populations. The approach has been adopted, in conjunction with morphometric analysis, to identify
Africanized bees for regulatory purposes in the United States such as in California. In this study, 211
Old World colonies, representing all known introduced subspecies in the United States, and 451
colonies from non-Africanized areas of the southern United States were screened to validate a rapid
PCR-based assay for identiÞcation of Africanized honey bee mtDNA. This PCR-based assay requires
a single enzyme digestion (BglII) of a single PCR-ampliÞed segment of the cytochrome b gene. The
BglII polymorphism discriminates the mitochondrial haplotype (mitotype) of Apis mellifera scutellata
L. (ancestor of Africanized bees) from that of A. m. mellifera, A. m. caucasia, A. m. ligustica, A. m.
carnica, A. m. lamarcki, A. m. cypria, A. m. syriaca, and some A. m. iberiensis, but not from that of
A. m. intermissa and some A. m. iberiensis. Nonetheless, given the very low frequency ( 1%) of African
non-A. m. scutellata mitotype present before arrival of Africanized bees in the United States, cytochrome
b/BglII assay can be used to identify maternally Africanized bees with a high degree of
reliability
Population Genetics of Bowhead Whales (Baleana mysticetus) in the Western Arctic
Bowhead whales (Balaena mysticetus) in the Bering, Chukchi, and Beaufort seas experienced a severe reduction as a result of commercial whaling in the 19th century. Since the cessation of commercial whaling, the population has recovered to a size that is approaching pre-whaling estimates. Inupiat and Yupik communities in northern and western Alaska hunt these Western Arctic (WA) bowheads along their migratory path during spring and fall. This hunting is regulated by the International Whaling Commission. Recent but preliminary analysis of available genetic data (207 whales and 10 microsatellite markers) raised the question of the presence of multiple, genetically distinct populations within the WA bowheads. Here we re-examined this question on the basis of a study of 414 whales and 22 newly developed microsatellite loci. We identified widespread departures from Hardy-Weinberg equilibrium; however, we were unable to detect significant evidence of multiple genetic populations within the WA bowheads that could explain this Hardy-Weinberg disequilibrium, particularly when compared to the strength of evidence for differentiation between WA bowheads and other populations from distant regions such as the Okhotsk Sea and eastern Canada. There was conclusive evidence of genetic differentiation among the three regions. The statistical rejection of panmixia within the WA improves our understanding of bowhead whale biology, and the lack of evidence for multiple populations within the WA enables risk-averse management of aboriginal hunting of Western Arctic bowhead whales.La population de baleines boréales (Balaena mysticetus) des mers de Béring, de Tchoukotka et de Beaufort a enregistré un grave déclin en raison de la pêche commerciale à la baleine au XIXe siècle. Depuis que la pêche commerciale à la baleine a cessé, la population de baleines boréales a connu un certain essor au point où elle approche maintenant les estimations de la taille qu’elle avait avant la pêche commerciale à la baleine. Les collectivités Inupiat et Yupik du nord et de l’ouest de l’Alaska chassent les baleines boréales de l’ouest de l’Arctique le long de leur voie de migration au printemps et à l’automne. La chasse est réglementée par l’International Whaling Commission. Des analyses récentes, bien que préliminaires, des données génétiques disponibles (207 baleines et 10 marqueurs microsatellites) ont soulevé la question de la présence de multiples populations génétiquement distinctes au sein de la population de baleines boréales de l’ouest de l’Alaska. Ici, nous avons réexaminé cette question en fonction de l’étude de 414 baleines et de 22 locis microsatellites nouvellement mis au point. Nous avons remarqué d’importantes déviations de l’équilibre de Hardy-Weinberg; toutefois, nous n’avons pas pu trouver de preuve significative de populations génétiques multiples au sein des baleines boréales de l’ouest de l’Alaska qui pourrait expliquer ce déséquilibre de Hardy-Weinberg, plus particulièrement en comparaison avec la force de la preuve de différenciation entre les baleines boréales de l’ouest de l’Arctique et d’autres populations de régions distantes telles que la mer d’Okhotsk et l’est du Canada. Il y avait des preuves concluantes de différenciation génétique entre les trois régions. Le rejet statistique de la panmixie au sein de l’ouest de l’Arctique améliore notre compréhension de la biologie des baleines boréales, et le manque de preuves de populations multiples dans l’ouest de l’Arctique donne lieu à la gestion de l’aversion au risque de la chasse à la baleine boréale de l’ouest de l’Arctique par les Autochtones
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