| 31071. |
- Dibattista, Joseph D., et al.
(författare)
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A genetic assessment of polyandry and breeding-site fidelity in lemon sharks
- 2008
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Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 17:14, s. 3337-3351
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Tidskriftsartikel (refereegranskat)abstract
- We here employ 11 microsatellite markers and recently developed litter reconstruction methods to infer mating system parameters (i.e. polyandry and breeding-site fidelity) at a lemon shark nursery site in Marquesas Key, Florida. Four hundred and eight juvenile or subadult sharks were genotyped over eight complete breeding seasons. Using this information, we were able to infer family structure, as well as fully or partially reconstruct genotypes of 46 mothers and 163 fathers. Multiple litter reconstruction methods were used, and novel simulations helped define apparent bias and precision of at least some mating system parameters. For Marquesas Key, we find that adult female lemon sharks display high levels of polyandry (81% of all litters sampled) and stronger fidelity to the nursery site than do males. Indeed, few male sharks sired offspring from more than one litter during the course of the study. These findings were quite similar to previous results from another lemon shark nursery site (Bimini, Bahamas), suggesting conserved mating system parameters despite significant variation in early life-history traits (i.e. body size and growth) among sites. The finding of at least some site fidelity in females also supports the need for careful conservation of each nursery.
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| 31072. |
- Dibattista, Michele, et al.
(författare)
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Calcium-activated chloride channels in the apical region of mouse vomeronasal sensory neurons
- 2012
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Ingår i: The Journal of General Physiology. - : Rockefeller University Press. - 0022-1295 .- 1540-7748. ; 140:1, s. 3-15
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Tidskriftsartikel (refereegranskat)abstract
- The rodent vomeronasal organ plays a crucial role in several social behaviors. Detection of pheromones or other emitted signaling molecules occurs in the dendritic microvilli of vomeronasal sensory neurons, where the binding of molecules to vomeronasal receptors leads to the influx of sodium and calcium ions mainly through the transient receptor potential canonical 2 (TRPC2) channel. To investigate the physiological role played by the increase in intracellular calcium concentration in the apical region of these neurons, we produced localized, rapid, and reproducible increases in calcium concentration with flash photolysis of caged calcium and measured calcium-activated currents with the whole cell voltage-clamp technique. On average, a large inward calcium-activated current of −261 pA was measured at −50 mV, rising with a time constant of 13 ms. Ion substitution experiments showed that this current is anion selective. Moreover, the chloride channel blockers niflumic acid and 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid partially inhibited the calcium-activated current. These results directly demonstrate that a large chloride current can be activated by calcium in the apical region of mouse vomeronasal sensory neurons. Furthermore, we showed by immunohistochemistry that the calcium-activated chloride channels TMEM16A/anoctamin1 and TMEM16B/anoctamin2 are present in the apical layer of the vomeronasal epithelium, where they largely colocalize with the TRPC2 transduction channel. Immunocytochemistry on isolated vomeronasal sensory neurons showed that TMEM16A and TMEM16B coexpress in the neuronal microvilli. Therefore, we conclude that microvilli of mouse vomeronasal sensory neurons have a high density of calcium-activated chloride channels that may play an important role in vomeronasal transduction.
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| 31073. |
- Dibattista, Michele, et al.
(författare)
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The cellular prion protein is expressed in olfactory sensory neurons of adult mice but does not affect the early events of the olfactory transduction pathway
- 2011
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Ingår i: Chemical Senses. - : Oxford University Press. - 0379-864X .- 1464-3553. ; 36:9, s. 791-797
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Tidskriftsartikel (refereegranskat)abstract
- A conformational conversion of the cellular prion protein (PrPC) is now recognized as the causal event of fatal neurodegenerative disorders, known as prion diseases. In spite of long-lasting efforts, however, the physiological role of PrPC remains unclear. It has been reported that PrPC is expressed in various areas of the olfactory system, including the olfactory epithelium, but its precise localization in olfactory sensory neurons (OSNs) is still debated. Here, using immunohistochemistry tools, we have reinvestigated the expression and localization of PrPC in the olfactory epithelium of adult congenic mice expressing different PrPC amounts, that is, wild-type, PrP-knockout, and transgenic PrPC-overexpressing animals. We found that PrPC was expressed in OSNs, in which, however, it was unevenly distributed, being detectable at low levels in cell bodies, dendrites and apical layer, and more abundantly in axons. We also studied the involvement of PrPC in the response of the olfactory epithelium to odorants, by comparing the electro-olfactograms of the 3 mouse lines subjected to different stimulation protocols. We found no significant difference between the 3 PrP genotypes, supporting previous reports that exclude a direct action of PrPC in the early signal transduction activity of the olfactory epithelium.
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| 31074. |
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| 31075. |
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| 31076. |
- Diboulo, Eric, et al.
(författare)
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Weather and mortality : a 10 year retrospective analysis of the Nouna Health and Demographic Surveillance System, Burkina Faso
- 2012
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Ingår i: Global Health Action. - : Informa UK Limited. - 1654-9716 .- 1654-9880. ; 5, s. 19078-
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Tidskriftsartikel (refereegranskat)abstract
- Background: A growing body of evidence points to the emission of greenhouse gases from human activity as a key factor in climate change. This in turn affects human health and wellbeing through consequential changes in weather extremes. At present, little is known about the effects of weather on the health of sub-Saharan African populations, as well as the related anticipated effects of climate change partly due to scarcity of good quality data. We aimed to study the association between weather patterns and daily mortality in the Nouna Health and Demographic Surveillance System (HDSS) area during 1999-2009. Methods: Meteorological data were obtained from a nearby weather station in the Nouna HDSS area and linked to mortality data on a daily basis. Time series Poisson regression models were established to estimate the association between the lags of weather and daily population-level mortality, adjusting for time trends. The analyses were stratified by age and sex to study differential population susceptibility. Results: We found profound associations between higher temperature and daily mortality in the Nouna HDSS, Burkina Faso. The short-term direct heat effect was particularly strong on the under-five child mortality rate. We also found independent coherent effects and strong associations between rainfall events and daily mortality, particularly in elderly populations. Conclusion: Mortality patterns in the Nouna HDSS appear to be closely related to weather conditions. Further investigation on cause-specific mortality, as well as on vulnerability and susceptibility is required. Studies on local adaptation and mitigation measures to avoid health impacts from weather and climate change is also needed to reduce negative effects from weather and climate change on population health in rural areas of the sub-Saharan Africa.
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| 31077. |
- Dicks, Matthew DJ, et al.
(författare)
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A novel chimpanzee adenovirus vector with low human seroprevalence : improved systems for vector derivation and comparative immunogenicity
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:7, s. e40385-
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Tidskriftsartikel (refereegranskat)abstract
- Recombinant adenoviruses are among the most promising tools for vaccine antigen delivery. Recently, the development of new vectors has focused on serotypes to which the human population is less exposed in order to circumvent preexisting anti vector immunity. This study describes the derivation of a new vaccine vector based on a chimpanzee adenovirus, Y25, together with a comparative assessment of its potential to elicit transgene product specific immune responses in mice. The vector was constructed in a bacterial artificial chromosome to facilitate genetic manipulation of genomic clones. In order to conduct a fair head-to-head immunological comparison of multiple adenoviral vectors, we optimised a method for accurate determination of infectious titre, since this parameter exhibits profound natural variability and can confound immunogenicity studies when doses are based on viral particle estimation. Cellular immunogenicity of recombinant E1 E3-deleted vector ChAdY25 was comparable to that of other species E derived chimpanzee adenovirus vectors including ChAd63, the first simian adenovirus vector to enter clinical trials in humans. Furthermore, the prevalence of virus neutralizing antibodies (titre >1:200) against ChAdY25 in serum samples collected from two human populations in the UK and Gambia was particularly low compared to published data for other chimpanzee adenoviruses. These findings support the continued development of new chimpanzee adenovirus vectors, including ChAdY25, for clinical use.
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| 31078. |
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| 31079. |
- Diderichsen, Finn, et al.
(författare)
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Gunnar Inghe: A founding father of Scandinavian social medicine and still highly relevant
- 2023
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Ingår i: Scandinavian Journal of Public Health. - : Sage Publications. - 1403-4948 .- 1651-1905. ; 51:4, s. 513-516
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Tidskriftsartikel (refereegranskat)abstract
- Gunnar Inghe (1910–1977) was a founding father of Scandinavian social medicine and the first editor of the Scandinavian Journal of Social Medicine. He worked as a physician for social care clients in Stockholm from 1944 to 1961 and was professor in social medicine from 1961 to 1975. We (F.D. and U.J.) were his last two PhD students. As we were recollecting the 50-year history of the Scandinavian Journal of Public Health in 2022, it became evident to us how relevant Gunnar Inghe’s work, 45 years after his death, still is for today’s social medicine, population health research and policy in Scandinavia. We shall explain why with five examples of Inghe’s work: reproductive health, health of paupers, foundation of the discipline, international solidarity and collaboration between medical and social care.
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| 31080. |
- Diderichsen, Saima, et al.
(författare)
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Few gender differences in specialty preferences and motivational factors : a cross-sectional Swedish study on last-year medical students
- 2013
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Ingår i: BMC Medical Education. - : Springer Science and Business Media LLC. - 1472-6920. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Today, women constitute about half of medical students in several Western societies, yet women physicians are still underrepresented in surgical specialties and clustered in other branches of medicine. Gender segregation in specialty preference has been found already in medical school. It is important to study the career preferences of our future physicians, as they will influence the maintenance of an adequate supply of physicians in all specialties and the future provision of health care. American and British studies dominate the area of gender and medical careers whereas Swedish studies on medical students' reasons for specialty preference are scarce. The aim of this study is to investigate and compare Swedish male and female medical students' specialty preferences and the motives behind them. Methods: Between 2006 and 2009, all last-year medical students at Umea University, Sweden (N = 421), were invited to answer a questionnaire about their future career and family plans. They were asked about their specialty preference and how they rated the impact that the motivational factors had for their choice. The response rate was 89% (N = 372); 58% were women (N = 215) and 42% were men (N = 157). Logistic regression was used to evaluate the independent impact of each motivational factor for specialty preference. Results: On the whole, male and female last-year students opted for similar specialties. Men and women had an almost identical ranking order of the motivational factors. When analyzed separately, male and female students showed both similarities and differences in the motivational factors that were associated with their specialty preference. A majority of the women and a good third of the men intended to work part-time. The motivational factor combining work with family correlated with number of working hours for women, but not for men. Conclusions: The gender similarities in the medical students' specialty preferences are striking and contrast with research from other Western countries where male and female students show more differences in career aspirations. These similarities should be seized by the health care system in order to counteract the horizontal gender segregation in the physician workforce of today.
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