161 research outputs found
Sexual behavior and factors affecting female reproduction in house and field crickets
The objective of this investigation was to clarify the
adaptive significance of female sexual behaviours in the house
cricket, Acheta domesticus, and the Texas field cricket, Gryllus
integer. Experiments were focussed primarily on: nutritional
factors affecting female reproductive success; the ontogeny of
female sexual behaviours; female mating frequency and progeny
production; and the pattern of sperm competition.
Reproduction of singly mated female A. domesticus assigned
to 3 nutritional regimes was compared . Females fed a vitamin
and protein-enriched mouse chow, cannibalistic females, and
starved females produced on the average, 513 , 200 and 68 offspring,
respectively. Cannibals probably could not obtain the same amounts
of essential nutrients as females fed mouse chow. Reabsorption
of oocytes was likely the major factor contributing to the
decreased reproduction of starved females. In addition, female
!. domesticus fed mouse chow, but allowed constant access to
males produced 11 times as many offspring than did females fed
corn meal. Females fed corn meal probably could not absorb or
synthesize enough dietary lipids, thus resulting in poor ovariole
growth.
Female !. domesticus first mate at an average adult age
of 7 days, closely corresponding to when they first exhibit
positive phonotaxis. Females mate repeatedly and often consume the externally attached spermatophore. In ~. domesticus, females
allowed constant access to males produced significantly more
offspring than did single maters. Similarly, doubly mated G.
integer females produced more offspring than did single maters.
This difference resulted largely from the failure of many single
maters to reproduce. Remating by female crickets partly functions
in offsetting the possibility of a failed initial mating. Nymph
production increased significantly with the time the spermatophore
was attached in singly mated ~. domesticus. Spermatophore
consumption by the female was not affected by male guarding
behaviour, and the interval between mating and eating of the
spermatophore may often be shorter than the time required for
maximum insemination. Some degree of sperm depletion in singly
mated !. domesticus and G. integer may have occurred. The
patterns of daily offspring production of singly and multiplymated
females suggests that a factor provided by a male during
mating stimulates female oviposition and/or egg production. Female
crickets also might acquire nutrition from spermatophore consumption,
a benefit that is augmented by female multiple mating. The
electrophoretic examination of various allozymes in ~. integer
did not permit determination of a pattern of sperm competition.
However, the possibility of last male sperm predominance is
related to male guarding behaviour
Impact of COVID-19 pandemic on utilisation of healthcare services: a systematic review
Objectives To determine the extent and nature of changes in utilisation of healthcare services during COVID-19 pandemic.Design Systematic review.Eligibility Eligible studies compared utilisation of services during COVID-19 pandemic to at least one comparable period in prior years. Services included visits, admissions, diagnostics and therapeutics. Studies were excluded if from single centres or studied only patients with COVID-19.Data sources PubMed, Embase, Cochrane COVID-19 Study Register and preprints were searched, without language restrictions, until 10 August, using detailed searches with key concepts including COVID-19, health services and impact.Data analysis Risk of bias was assessed by adapting the Risk of Bias in Non-randomised Studies of Interventions tool, and a Cochrane Effective Practice and Organization of Care tool. Results were analysed using descriptive statistics, graphical figures and narrative synthesis.Outcome measures Primary outcome was change in service utilisation between prepandemic and pandemic periods. Secondary outcome was the change in proportions of users of healthcare services with milder or more severe illness (eg, triage scores).Results 3097 unique references were identified, and 81 studies across 20 countries included, reporting on >11 million services prepandemic and 6.9 million during pandemic. For the primary outcome, there were 143 estimates of changes, with a median 37% reduction in services overall (IQR −51% to −20%), comprising median reductions for visits of 42% (−53% to −32%), admissions 28% (−40% to −17%), diagnostics 31% (−53% to −24%) and for therapeutics 30% (−57% to −19%). Among 35 studies reporting secondary outcomes, there were 60 estimates, with 27 (45%) reporting larger reductions in utilisation among people with a milder spectrum of illness, and 33 (55%) reporting no difference.Conclusions Healthcare utilisation decreased by about a third during the pandemic, with considerable variation, and with greater reductions among people with less severe illness. While addressing unmet need remains a priority, studies of health impacts of reductions may help health systems reduce unnecessary care in the postpandemic recovery.PROSPERO registration number CRD42020203729
Epidemiology of melanoma in rural southern Queensland
Objective: The objective of this study is to define the epidemiology of melanoma in rural communities in southern Queensland.
Design: The design used was a 6‐year clinical record audit of melanoma cases identified by billing records and electronic clinical records, confirmed and typed with
histology.
Setting and Participants: This study was based on seven agricultural communities on the Darling Downs with patients presenting to local primary care clinics.
Main outcome measures: Outcomes measured were confirmed type, depth and anatomic distribution of melanoma identified at these practices during the study period.
Results: The results from 317 cases of melanoma found anatomic distribution was significantly different (χ2 = 9.6, P < 0.05) to that reported previously from the
Queensland Cancer Registry. A high proportion (87%) of melanoma diagnosed by these general practitioners were 1 mm or less when treated.
Conclusions: Conclusions drawn from these findings are that melanoma risk is not so much lesser in rural, inland communities compared with coastal and metropolitan
regions, but different. Differences may relate to comprehensive data capture available in rural community studies and to different sun exposure and protection behaviours. The higher proportion of melanoma identified at early stages suggests rural primary care is an effective method of secondary prevention
Biogeography in the deep : hierarchical population genomic structure of two beaked whale species
Funding for this research was provided by the Office of Naval Research, Award numbers N000141613017 and N000142112712. ABO was supported by a partial studentship from the University of St Andrews, School of Biology; OEG by the Marine Alliance for Science and Technology for Scotland (Scottish Funding Council grant HR09011); ELC by a Rutherford Discovery Fellowship from the Royal Society of New Zealand Te Aparangi; NAS by a Ramon y Cajal Fellowship from the Spanish Ministry of Innovation; MLM by the European Union’s Horizon 2020 Research and Innovation Programme (Marie Skłodowska-Curie grant 801199); CR by the Marine Institute (Cetaceans on the Frontier) and the Irish Research Council; and MTO by the Hartmann Foundation.The deep sea is the largest ecosystem on Earth, yet little is known about the processes driving patterns of genetic diversity in its inhabitants. Here, we investigated the macro- and microevolutionary processes shaping genomic population structure and diversity in two poorly understood, globally distributed, deep-sea predators: Cuvier’s beaked whale (Ziphius cavirostris) and Blainville’s beaked whale (Mesoplodon densirostris). We used double-digest restriction associated DNA (ddRAD) and whole mitochondrial genome (mitogenome) sequencing to characterise genetic patterns using phylogenetic trees, cluster analysis, isolation-by-distance, genetic diversity and differentiation statistics. Single nucleotide polymorphisms (SNPs; Blainville’s n = 43 samples, SNPs=13988; Cuvier’s n = 123, SNPs= 30479) and mitogenomes (Blainville’s n = 27; Cuvier’s n = 35) revealed substantial hierarchical structure at a global scale. Both species display significant genetic structure between the Atlantic, Indo-Pacific and in Cuvier’s, the Mediterranean Sea. Within major ocean basins, clear differentiation is found between genetic clusters on the east and west sides of the North Atlantic, and some distinct patterns of structure in the Indo-Pacific and Southern Hemisphere. We infer that macroevolutionary processes shaping patterns of genetic diversity include biogeographical barriers, highlighting the importance of such barriers even to highly mobile, deep-diving taxa. The barriers likely differ between the species due to their thermal tolerances and evolutionary histories. On a microevolutionary scale, it seems likely that the balance between resident populations displaying site fidelity, and transient individuals facilitating gene flow, shapes patterns of connectivity and genetic drift in beaked whales. Based on these results, we propose management units to facilitate improved conservation measures for these elusive species.Publisher PDFPeer reviewe
Mental health literacy in an educational elite – an online survey among university students
BACKGROUND: Mental health literacy is a prerequisite for early recognition and intervention in mental disorders. The aims of this paper are to determine whether a sample of university students recognise different symptoms of depression and schizophrenia and to reveal factors influencing correct recognition. METHODS: Bivariate and correspondence analyses of the results from an online survey among university students (n = 225). RESULTS: Most participants recognised the specific symptoms of depression. The symptoms of schizophrenia were acknowledged to a lower extent. Delusions of control and hallucinations of taste were not identified as symptoms of schizophrenia. Repeated revival of a trauma for depression and split personality for schizophrenia were frequently mistaken as symptoms of the respective disorders. Bivariate analyses demonstrated that previous interest in and a side job related to mental disorders, as well as previous personal treatment experience had a positive influence on symptom recognition. The correspondence analysis showed that male students of natural science, economics and philosophy are illiterate in recognising the symptoms depression and schizophrenia. CONCLUSION: Among the educational elite, a wide variability in mental health literacy was found. Therefore, it's important for public mental health interventions to focus on the different recognition rates in depression and schizophrenia. Possibilities for contact must be arranged according to interest and activity (e.g., at work). In order to improve mental health literacy, finally, education and/or internship should be integrated in high school or apprenticeship curricula. Special emphasis must be given towards the effects of gender and stereotypes held about mental illnesses
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