Moses or Ishmael

https://digitalcommons.acu.edu/crs_books/1260/thumbnail.jp

Cell proliferation and differentiation kinetics during spermatogenesis in Hydra carnea

Spermatogenesis inHydra carnea was investigated. The cell proliferation and differentiation kinetics of intermediates in the spermatogenesis pathway were determined, using quantitative determinations of cell abundance, pulse and continuous labelling with3H-thymidine and nuclear DNA measurements. Testes develop in the ectoderm of male hydra as a result of interstitial cell proliferation. Gonial stem cells and proliferating spermatogonia have cell cycles of 28 h and 22 h, respectively. Stem cells undergo four, five or six cell divisions prior to meiosis which includes a premeiotic S+G2 phase of 20 h followed by a long meiotic prophase (22 h). Spermatid differentiation requires 12–29 h. When they first appear, testes contain only proliferating spermatogonia; meiotic and postmeiotic cells appear after 2 and 3 days, respectively and release of mature sperm begins after 4 days. Mature testes produce about 27,000 sperm per day over a period of 4–6 days: about 220 gonial stem cells per testis are required to support this level of sperm differentiation. Further results indicate that somatic (e.g. nematocyte) differentiation does not occur in testes although it continues normally in ectodermal tissue outside testes. Our results support the hypothesis that spermatogenesis is controlled locally in regions of the ectoderm where testes develop

Strengthening intellectually challenged adolescents’ sense of self: An appreciative inquiry mixed-methods intervention

Background: Individuals with intellectual challenges may experience a sense of isolation within their families. How their families and friends react towards these challenges influences the formation of their identity and self-acceptance significantly. Aim: The aim of this research was to explore and describe how the sense of self of intellectually challenged adolescents could be strengthened within familial relationships and to evaluate the effectiveness of appreciative inquiry as an intervention approach. Setting: The study was conducted with families at a school for children with intellectual disabilities in the Ekurhuleni Metropolitan Area, Northern Region of Gauteng, South Africa. Methods: In an embedded mixed-method approach, a sample of 24 intellectually challenged adolescents and their families were selected, tested and interviewed. Quantitative data were collected using the BarOn Emotional Quotient Inventory (BarOn EQ-i:YV) on adolescents and the Family Environmental Scale (FES) on families in the experimental and control groups, before and after intervention. Qualitative data were gathered through an appreciative inquiry intervention and semi-structured interviews with adolescents in the experimental group. Results: Although the quantitative findings were not statistically significant, the qualitative findings indicated that adolescents and family members experienced the sense of self of intellectually challenged adolescents positively, rather than as ‘disabled’. The appreciative inquiry shows potential to strengthen intellectually challenged adolescents’ sense of self in a supportive, positive family environment. Conclusion: The research is valuable in the way it highlights the importance of relational research in cases where quantitative research does not seem to be effective

Functional Social Support Moderates Stress on Depression in Individuals with CID during the COVID-19 Pandemic: A Two-Wave Study.

Depression is a common psychological experience for those living with a chronic illness and disease (CID). Social support (SS) can influence psychological health by regulating emotional functioning. The functional domain of SS refers to supportive exchange, including the emotional and instrumental functions. Public health measures during the COVID-19 pandemic include social distancing and isolation, which have impacted functional aspects of SS. The health risks of being isolated are comparable to the risks linked to obesity, blood pressure, and cigarette smoking. PURPOSE: To investigate the moderating effect of functional SS on the stress-depression relationship on individuals with CID during the COVID-19 pandemic. METHODS: Two waves of data were collected from a US sample: Apr. ’20: N = 321; Jun. ’20: N = 238. Participants completed the Patient Health Questionnaire–9 (depression symptoms), the Medical Outcomes Study–Social Support Survey–8 (perceived social support), and the Perceived Stress Scale–10 (perceived stress). For each wave of data, social support was entered as a moderator of the stress-depression relationship via multiple regression. RESULTS: The moderation models were estimated separately by wave. In the first wave, there was a negative but nonsignificant moderating effect (b = -0.19, p = .10) of social support on the stress-depression relationship (R2 = 51). In the second wave, the moderating relationship of social support doubled in magnitude (b = -0.30, p = .03, R2 = .57). During the COVID pandemic, functional social support weakened the association between stress and depression. CONCLUSION: Given the increased risk for social isolation and negative social exchange among people with CID during the COVID-19 pandemic, practitioners in rehabilitation psychology need to be informed about the potential implications of a lack of SS for the psychological health of the CID clients they work with. Drawing from the stress-buffering model and Lazarus et al.’s stress and coping theory (Lazarus, 1966; Lazarus & Folkman, 1984), our findings indicate that increased levels of perceived support can reduce the effects of stress on depression during the pandemic by contributing to fewer negative appraisals. Interventions targeting the particular functions of emotional (e.g., opportunities for emotional expression and venting) and instrumental (e.g., material aid) support could have immediate implications for facilitating rehabilitation outcomes (e.g., quality of life, interpersonal functioning, psychiatric symptomatology) during this public health crisis

Lateral Gene Expression in Drosophila Early Embryos Is Supported by Grainyhead-Mediated Activation and Tiers of Dorsally-Localized Repression

The general consensus in the field is that limiting amounts of the transcription factor Dorsal establish dorsal boundaries of genes expressed along the dorsal-ventral (DV) axis of early Drosophila embryos, while repressors establish ventral boundaries. Yet recent studies have provided evidence that repressors act to specify the dorsal boundary of intermediate neuroblasts defective (ind), a gene expressed in a stripe along the DV axis in lateral regions of the embryo. Here we show that a short 12 base pair sequence (“the A-box”) present twice within the ind CRM is both necessary and sufficient to support transcriptional repression in dorsal regions of embryos. To identify binding factors, we conducted affinity chromatography using the A-box element and found a number of DNA-binding proteins and chromatin-associated factors using mass spectroscopy. Only Grainyhead (Grh), a CP2 transcription factor with a unique DNA-binding domain, was found to bind the A-box sequence. Our results suggest that Grh acts as an activator to support expression of ind, which was surprising as we identified this factor using an element that mediates dorsally-localized repression. Grh and Dorsal both contribute to ind transcriptional activation. However, another recent study found that the repressor Capicua (Cic) also binds to the A-box sequence. While Cic was not identified through our A-box affinity chromatography, utilization of the same site, the A-box, by both factors Grh (activator) and Cic (repressor) may also support a “switch-like” response that helps to sharpen the ind dorsal boundary. Furthermore, our results also demonstrate that TGF-β signaling acts to refine ind CRM expression in an A-box independent manner in dorsal-most regions, suggesting that tiers of repression act in dorsal regions of the embryo

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011