5,221 research outputs found

    Genetic analysis of Eclosion hormone action during Drosophila larval ecdysis

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    Insect growth is punctuated by molts, during which the animal produces a new exoskeleton. The molt culminates with ecdysis, an ordered sequence of behaviors that causes the old cuticle to be shed. This sequence is activated by Ecdysis Triggering Hormone (ETH), which acts on the CNS to activate neurons that produce neuropeptides implicated in ecdysis, including Eclosion hormone (EH), Crustacean Cardioactive Peptide (CCAP), and bursicon. Despite over 40 years of research on ecdysis, our understanding of the precise roles of these neurohormones remains rudimentary. Of particular interest is EH, whose role beyond the well-accepted action of massively upregulating ETH release has remained elusive. We report on the isolation of an eh null mutant in Drosophila, and use it to investigate the role of EH in larval ecdysis. We found that null mutant animals invariably died at around the time of ecdysis, revealing an essential role in its control. Unexpectedly, however, they failed to express the preparatory behavior of pre-ecdysis while directly expressing the motor program of ecdysis. In addition, although ETH release could not be detected in these animals, the lack of pre-ecdysis could not be rescued by injections of ETH, suggesting that EH is required within the CNS for ETH to trigger the normal ecdysial sequence. Using a genetically-encoded calcium probe we show that EH configures the response of the CNS to ETH. These findings show that EH plays an essential role in the Drosophila CNS in the control of ecdysis, in addition to its known role in the periphery of triggering ETH release.</jats:p

    Immunisation coverage and its associations in rural Tanzanian infants

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    Introduction: In Tanzania, vaccination rates (VRs) range from 80% to 90% for standard vaccines, but little information is available about rural populations and nomadic pastoralists. This study investigates levels and trends of the immunisation status of infants at eight mobile reproductive-and-child-health (RCH) clinics in a rural area in northern Tanzania (with a large multi-tribal population that has a significant population of nomadic pastoralists) for the years 1998, 1999, 2006 and 2007. In addition, the influence of tribal affiliation and health system-related factors on the immunisation status in this population is analysed. Methods: Vaccination data of 3868 infants for the standard bacillus Calmette–GuĂ©rin (BCG), poliomyelitis, diphtheria, pertussis, tetanus and measles vaccines were obtained from the RCH clinic records retrospectively, and coverage for both single vaccines and full vaccination by the end of first year of life were calculated. These results were correlated with data on predominant tribal affiliation at the clinic site, skilled attendance at birth, service provision and vaccine availability as independent variables.Results: In 1998, the full vaccination rate (FVR) across all RCH clinics was 72%, significantly higher than in the other years (1999: 58%; 2006: 58%; 2007: 57%) (p 80% was only achieved at one clinic during 3 years. No clinic showed a consistent increase of VRs over time. In univariate analysis, predominant tribal affiliation (Datoga tribe) was associated with a low FVR (odds ratio (OR) 4.6 (95% confidence interval (CI) 3.8–5.5)), as were low rates of skilled attendance at birth (OR 3.6 (CI 2.9–4.4)). Other health system-related factors associated with low FVRs included interruption of scheduled monthly immunisation clinics (OR 9.8 (CI 2.1–45.5)) and lack of vaccines (OR 1.2–2.9, depending on vaccine). In multivariate analysis, predominant Datoga tribal affiliation and lack of vaccines retained their association with the risk of low rates of vaccination. Conclusions: Vaccination rates in this difficult-to-reach population are markedly lower than the national average for almost all years and clinics. Affiliation to the nomadic Datoga tribe and lack of vaccines determine VRs in this rural population. Improvements in immunisation service delivery, vaccine availability, stronger involvement of the nomadic communities and special outreach services for this population are required to improve VRs in these remote areas of Tanzania

    The impact of COVID-19 on routine patient care from a laboratory perspective

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    Background. Globally, few studies have examined the effect of the COVID-19 pandemic on routine patient care and follow-up.Objectives. To evaluate the effect of the COVID-19 response on biochemical test requests received from outpatient departments (OPDs) and peripheral clinics serviced by the National Health Laboratory Service Chemical Pathology Laboratory at Tygerberg Hospital, Cape Town, South Africa (SA). Request volumes were used as a measure of the routine care of patients, as clinical information was not readily available.Methods. A retrospective audit was conducted. The numbers of requests received from OPDs and peripheral clinics for creatinine, glycated haemoglobin (HbA1c), lipid profiles, thyroid-stimulating hormone (TSH), free thyroxine, free tri-iodothyronine (fT3), serum and urine protein electrophoresis, serum free light chains and neonatal total serum bilirubin were obtained from 1 March to 30 June for 2017, 2018, 2019 and 2020.Results. The biggest impact was seen on lipids, creatinine, HbA1c, TSH and fT3. The percentage reduction between 1 March and 30 June 2019 and between 1 March and 30 June 2020 was 59% for lipids, 64% for creatinine and HbA1c, 80% for TSH and 81% for fT3. There was a noteworthy decrease in overall analyte testing from March to April 2020, coinciding with initiation of level 5 lockdown. Although an increase in testing was observed during June 2020, the number of requests was still lower than in June 2019.Conclusions. This study, focusing on the short-term consequences of the SA response to the COVID-19 pandemic, found that routine follow-up of patients with communicable and non-communicable diseases was affected. Future studies are necessary to evaluate the long-term consequences of the pandemic for these patient groups.

    Digging deeper : Assessing the predictive power of common greenhouse gas accounting tools for soil carbon sequestration under organic amendment

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    Funding Information: The work that led to this publication was supported by the Washington State Legislature , the USDA-NIFA Organic Research and Extension Initiative Program (project nos. 2014-38421-22002 and 2019-51300-30476 ), and the CAHNRS Office of Research at Washington State University (Hatch project 1017286 ). For the Puyallup field trials, we thank Emma Rast for her assistance in field and laboratory analysis and Liz Myhre for technical assistance, and Craig Cogger and Andy Bary for their efforts to initiate and operate a long-term organic farming research experiment at WSU Puyallup from 2003 to 2016. These trials were funded by the Western Sustainable Agriculture Research and Education Program (project no. SW-03-040), the USDA NIFA Integrated Organic Program (project no. WNP07725), and the Agricultural Research Center at Washington State University (Hatch Project 0722). For the Davenport (Wilke Farm) field trials, we thank Rachel Zuger, Nicole Tautges, and Holly Lane. Publisher Copyright: © 2023 The AuthorsPeer reviewedPublisher PD

    Many-body nodal hypersurface and domain averages for correlated wave functions

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    We outline the basic notions of nodal hypersurface and domain averages for antisymmetric wave functions. We illustrate their properties and analyze the results for a few electron explicitly solvable cases and discuss possible further developments

    A Stellar Population Gradient in VII Zw 403 - Implications for the Formation of Blue Compact Dwarf Galaxies

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    We present evidence for the existence of an old stellar halo in the Blue Compact Dwarf galaxy VII Zw 403. VII Zw 403 is the first Blue Compact Dwarf galaxy for which a clear spatial segregation of the resolved stellar content into a "core-halo" structure is detected. Multicolor HST/WFPC2 observations indicate that active star formation occurs in the central region, but is strikingly absent at large radii. Instead, a globular-cluster-like red giant branch suggests the presence of an old (> 10 Gyr) and metal poor (=-1.92) stellar population in the halo. While the vast majority of Blue Compact Dwarf galaxies has been recognized to possess halos of red color in ground-based surface photometry, our observations of VII Zw 403 establish for the first time a direct correspondence between a red halo color and the presence of old, red giant stars. If the halos of Blue Compact Dwarf galaxies are all home to such ancient stellar populations, then the fossil record conflicts with delayed-formation scenarios for dwarfs.Comment: Accepted for publication in the Ap
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