544 research outputs found
Bivariate stochastic modeling of functional response with natural mortality
A correction due to Abbott (1925) is the standard method of dealing with control mortality in insect bioassay to estimate the mortality of an insect conditional on control mortality not having occurred. In this article a bivariate stochastic process for overall mortality is developed in which natural mortality and predation are jointly modeled to take account of the competing-risks associated with prey loss. The total mortality estimate from this model is essentially identical with that from more classical modeling. However, when predation loss is estimated in the absence of control mortality the results are somewhat different, with the estimate from the bivariate model being lower than that from using Abbott’s formula in conjunction with the classical model. It is argued that overdispersion in observed mortality data corresponds to correlated outcomes (death or survival) for the prey initially present, while Abbott’s correction relies implicitly on independence
Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms
<p>Background: E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity.</p>
<p>Methods: A cross-sectional survey of Scottish cattle farms was conducted in the period Feb 2002-Feb 2004 to determine the prevalence of E. coli O157 in cattle herds. Data from 88 farms on which E. coli O157 was present were analysed using generalised linear mixed models to identify risk factors for the presence of PT 21/28 specifically.</p>
<p>Results: The analysis identified private water supply, and northerly farm location as risk factors for PT 21/28 presence. There was a significant association between the presence of PT 21/28 and an increased number of E. coli O157 positive pat samples from a farm, and PT 21/28 was significantly associated with larger E. coli O157 counts than non-PT 21/28 E. coli O157.</p>
<p>Conclusion: PT 21/28 has significant risk factors that distinguish it from other phage types of E. coli O157. This finding has implications for the control of E. coli O157 as a whole and suggests that control could be tailored to target the locally dominant PT.</p>
Using conversational data to determine lexical frequency in British Sign Language: The influence of text type
This paper presents findings from an objective lexical frequency study in British Sign Language (BSL) based on 24,823 tokens collected as part of the BSL Corpus Project. The BSL study is only the fourth objective frequency study involving sign languages to be reported and is also the first study for any sign language to be based on entirely on spontaneous conversational data. When compared to previous frequency studies (both spoken and signed), some similarities can be observed although differences that may be attributed to text type are also recorded. When compared with subjective frequency ratings collected for BSL, a positive relationship is reported (similar to what has been observed for spoken languages). This is in contrast to a previous study which suggested a much weaker relationship between the two; however, this conclusion was based on a frequency count derived from narratives. These differences highlight the importance of using frequency measures derived from natural and spontaneous data, an opinion that has been emphasised in the spoken language literature
Factors contributing to late presentation of breast cancer in Africa: a systematic literature review
Background: Over 50% of people diagnosed with breast cancer in most African countries present late and report to the hospital with advanced stage III and IV disease, a major reason for the poor survival rate. This study reviewed studies focusing on patient-related factors or reasons contributing to the late presentation or delayed diagnosis of breast cancer in Africa. Method: A rigorous literature search was conducted with search terms “Breast Neoplasms” AND “Late Presentation” OR “Delayed Diagnosis” AND “Africa” OR “the name of any of the African countries” within CINAHL, African Index Medicus, MEDLINE, Web of Science and PsycINFO electronic databases. Additional hand searching of reference lists of included articles was conducted. A thematic synthesis was conducted. Result: Of the eighty-two studies identified, nine were eligible and included in the review. Studies included were conducted in Egypt, Nigeria, Ghana, Kenya and Libya. The factors identified as contributing to late presentation of breast cancer among most African women were negative symptom interpretation, fear, belief in alternative medicine, social relations and networks, lack of trust and confidence in orthodox medicine, and access to healthcare. Conclusion: A complex matrix of factors were identified that contribute to the late presentation or delayed diagnosis of breast cancer among most African women. The orthodox medical system in most African countries is gradually losing their relationship and credibility because of false reassurance, frequent misdiagnosis and strike actions, which is leading to late presentation of breast cancer
P4_5 Atmospheric ODSTs
In this paper the maximum acceleration on the ODST and the pod was found to be , with a braking thrusters force of N during the last m of descent. This deceleration brings the impact velocity of the pod to below velocity of ms, should the braking thrusters fail to fire the pod will hit the ground with a velocity of ms killing the trooper
P4_2 How to fly your dragon
In this paper we calculate the minimum area and length of a dragon’s wing for it to be able to fly. The minimum area was calculated to be 224m^2 and the length was 35.6m
A comparison of three outcome measures of the impact of vasomotor symptoms on women’s lives
Objective: Measures of the impact of vasomotor symptoms (VMS) have been used as outcomes in clinical trials but have not been compared. This study compares the Hot Flush Rating Scale (HFRS), the Hot Flash Related Daily Interference Scale (HFRDIS), and the shorter Hot Flash Interference (HFI) scale. Methods: Baseline data were taken from two studies including healthy women (menopause transition or postmenopause) and breast cancer patients experiencing VMS. Participants completed questionnaires on sociodemographics, the HFRS, the HFRDIS, the HFI, the Work and Social Adjustment Scale (WSAS), on depression (Generalized Anxiety Disorder 7), on anxiety (Patient Health Questionnaire 9), and on use of medical services. Results: A total of 169 women (129 with history of breast cancer and 40 without) aged 54.47 (standard deviation [SD] = 9.11) years took part. They had an average of 66 (SD = 40.94) VMS per week, with a mean HFRS problem-rating of 6.53 (SD = 1.99), HFRDIS score of 5.36 (SD = 2.22), and HFI score of 6.13 (SD = 2.30). The HFRS problem-rating, HFRDIS, and HFI were significantly associated (r = 0.61–0.85), had good internal reliability (α = 0.76–0.91), and had significant concurrent validity with mood, the WSAS, and use of medical services. VMS frequency was not associated with mood, the WSAS, or use of medical services. Conclusion: The HFRS problem-rating scale and the HFI are two brief, three-item measures that measure a similar concept of VMS interference/impact, with evidence of reliability and validity.</p
P4_4 Snorlax used Body Slam
In this paper we consider the maximum strength of Ash's Snorlax, from the Pokemon original TV series, this will occur when the Snorlax jumps as high as it can. The maximum height of the jump was calculated to be 41.8 m, the velocity it impacts the ground with is 28.1 ms^-1 and the momentum of the Snorlax when it hits the ground is 12,900 kgms^-1
P4_3 Light Ordnance
In this paper we consider a weapon system that fires a laser at an interplanetary vessel. We calculate the energy required to melt through a vessel’s armoured hull, of thickness 0.254 m, from a shot from a laser with a calibre of 16 inches. The energy required is found to be E = 34449 J. Using this energy, the recoil of the laser firing was calculated to be ρ = 1.15x10−4 kgms−1
P4_6 Wind swept
This paper discusses the plausibility of the thruster in the Iron Man suit being used as weapons to push a human back. It was determined that the shock-wave produced by the change in temperature due to the thrusters would produce a force of kN on a person it was shot at, this would cause the person to accelerate at ms killing the person
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