Interstellar medium disruption in the Centaurus A group

We present the results of a 21 cm neutral hydrogen (HI) line detection experiment in the direction of 18 low luminosity dwarf galaxies of the Centaurus A group, using the Australia Telescope National Facility 64m Parkes Radio Telescope and the Australia Telescope Compact Array. Five dwarfs have HI masses between M_HI=4x10^5 to M_HI=2.1x10^7 Msol and 0.04<M_HI/L_B<1.81 Msol L_{sol, B}^-1. The other 13 have upper-limits between M_HI<5x10^5 and M_HI<4x10^6 Msol (M_HI}/L_B<0.24 Msol L_{sol, B}^-1). Two of the mixed-morphology dwarfs remain undetected in HI, a situation that is in contrast to that of similar Local Group and Sculptor group objects where all contain significant amounts of neutral gas. There is a discontinuity in the HI properties of Centaurus A group low luminosity dwarfs that is unobserved amongst Sculptor group dwarfs. All objects fainter than M_B=-13 have either M_HI>10^7 Msol or M_HI<10^6 Msol. This gap may be explained by the ram pressure stripping mechanism at work in this dense environment where all galaxies with M_HI<10^7 Msol have been stripped of their gas. The required intergalactic medium density to achieve this is ~10^-3 cm^-3.Comment: 7 figures, 2 table

El cultivar de tomate mykonos y su relación con una población del neamatodo nacobbus aberrans

Fil: Cabrera, V. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; ArgentinaFil: Dottori, N. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Doucet, M. E. Universidad Nacional de Córdoba. CZA. Laboratorio de Nematología; Argentina.El tomate es la hortaliza más cultivada mundialmente y de mayor valor económico. Su productividad está limitada por plagas, destacándose el nematodo fitoparásito Nacobbus aberrans. El cultivar Mykonos se comercializa como resistente a nematodos, sin precisar la identidad específica del parásito.Fil: Cabrera, V. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; ArgentinaFil: Dottori, N. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Doucet, M. E. Universidad Nacional de Córdoba. CZA. Laboratorio de Nematología; Argentina.Ciencias de las Plantas, Botánic

El cultivar de tomate superman y una población del nematodo nacobbus aberrans

Fil: Cabrera, V. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Dottori, N. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Doucet, M. E. Universidad Nacional de Córdoba. CZA. Laboratorio de Nematología; Argentina.El tomate es una hortaliza de gran importancia en numerosos países; su cultivo ha adquirido relevancia económica en todo el mundo. Sin embargo, la productividad está severamente limitada por plagas y enfermedadesFil: Cabrera, V. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Dottori, N. Universidad Nacional de Córdoba. Instituto Multidiciplinario de Biología Vegetal; Argentina.Fil: Doucet, M. E. Universidad Nacional de Córdoba. CZA. Laboratorio de Nematología; Argentina.Ciencias de las Plantas, Botánic

HST/WFPC2 and VLT/ISAAC observations of PROPLYDS in the giant HII region NGC 3603

We report the discovery of three proplyd-like structures in the giant HII region NGC 3603. The emission nebulae are clearly resolved in narrow-band and broad-band HST/WFPC2 observations in the optical and broad-band VLT/ISAAC observations in the near-infrared. All three nebulae are tadpole shaped, with the bright ionization front at the head facing the central cluster and a fainter ionization front around the tail pointing away from the cluster. Typical sizes are 6,000 A.U. x 20,000 A.U. The nebulae share the overall morphology of the proplyds (``PROto PLanetarY DiskS'') in Orion, but are 20 to 30 times larger in size. Additional faint filaments located between the nebulae and the central ionizing cluster can be interpreted as bow shocks resulting from the interaction of the fast winds from the high-mass stars in the cluster with the evaporation flow from the proplyds. The striking similarity of the tadpole shaped emission nebulae in NGC 3603 to the proplyds in Orion suggests that the physical structure of both types of objects might be the same. We present 2D radiation hydrodynamical simulations of an externally illuminated star-disk-envelope system, which was still in its main accretion phase when first exposed to ionizing radiation from the central cluster. The simulations reproduce the overall morphology of the proplyds in NGC 3603 very well, but also indicate that mass-loss rates of up to 10^-5 Mo/yr are required in order to explain the size of the proplyds. (abbreviated)Comment: 10 pages, 4 Postscript figures, uses emulateapj.sty and psfig.tex. Astronomical Journal, in press (January 2000 issue

Enteric Neural Cells From Hirschsprung Disease Patients Form Ganglia in Autologous Aneuronal Colon

Background & Aims: Hirschsprung disease (HSCR) is caused by failure of cells derived from the neural crest (NC) to colonize the distal bowel in early embryogenesis, resulting in absence of the enteric nervous system (ENS) and failure of intestinal transit postnatally. Treatment is by distal bowel resection, but neural cell replacement may be an alternative. We tested whether aneuronal (aganglionic) colon tissue from patients may be colonized by autologous ENS-derived cells. Methods: Cells were obtained and cryopreserved from 31 HSCR patients from the proximal resection margin of colon, and ENS cells were isolated using flow cytometry for the NC marker p75 (nine patients). Aneuronal colon tissue was obtained from the distal resection margin (23 patients). ENS cells were assessed for NC markers immunohistologically and by quantitative reverse-transcription polymerase chain reaction, and mitosis was detected by ethynyl-2\u27-deoxyuridine labeling. The ability of human HSCR postnatal ENS-derived cells to colonize the embryonic intestine was demonstrated by organ coculture with avian embryo gut, and the ability of human postnatal HSCR aneuronal colon muscle to support ENS formation was tested by organ coculture with embryonic mouse ENS cells. Finally, the ability of HSCR patient ENS cells to colonize autologous aneuronal colon muscle tissue was assessed. Results: ENS-derived p75-sorted cells from patients expressed multiple NC progenitor and differentiation markers and proliferated in culture under conditions simulating Wnt signaling. In organ culture, patient ENS cells migrated appropriately in aneural quail embryo gut, and mouse embryo ENS cells rapidly spread, differentiated, and extended axons in patient aneuronal colon muscle tissue. Postnatal ENS cells derived from HSCR patients colonized autologous aneuronal colon tissue in cocultures, proliferating and differentiating as neurons and glia. Conclusions: NC-lineage cells can be obtained from HSCR patient colon and can form ENS-like structures in aneuronal colonic muscle from the same patient

Beyond the HPA-axis: Exploring maternal prenatal influences on birth outcomes and stress reactivity

Accumulating evidence suggests that antenatal maternal stress is associated with altered behavioral and physiological outcomes in the offspring, however, whether this association is causal and the underlying biological mechanisms remain largely unknown. While the most studied mediator of maternal stress influences on the fetus has generally been cortisol, alternative novel markers of stress or inflammation warrant further consideration. The current investigation explored the influence of variations in self-reported symptoms of distress, stress hormones and inflammatory markers on infant birth outcomes and early stress regulation. The sample consisted of 104 pregnant women (mean gestational age = 34.76; SD = 1.12) and their healthy newborns. Maternal self-reported symptoms of depression and anxiety were evaluated through the Edinburgh Postnatal Depression Scale and the State-Trait Anxiety Inventory and levels of serum Interleukine-6 (IL-6), C-Reactive Protein (CRP), salivary cortisol and alpha amylase (sAA) were measured in late pregnancy. Newborns’ cortisol and behavioral response to the heel-stick was assessed 48–72 hours after birth. The associations between maternal stress measures and infant birth outcomes and stress reactivity, adjusted for potential confounders, were examined through hierarchical linear regressions and hierarchical linear models. Higher maternal IL-6 levels were associated with smaller head circumference at birth, while diurnal sAA levels were positively associated with birthweight. Maternal diurnal cortisol was related to newborn’s stress reactivity: a flatter infant cortisol response to the heel-stick was associated with greater maternal cortisol increases after awakening during pregnancy, while greater infant behavioural reactivity was related to a flatter maternal diurnal cortisol profile. The observational nature of these data does not allow for causal inferences but the current findings illustrate that antenatal factors related to alterations in maternal stress and immune response systems are associated with fetal growth and neonatal stress reactivity. This may have implications for later health and psychological outcomes

Utility of the FebriDx point-of-care assay in supporting a triage algorithm for medical admissions with possible COVID-19: an observational cohort study

Objective: To evaluate a triage algorithm used to identify and isolate patients with suspected COVID-19 among medical patients needing admission to hospital using simple clinical criteria and the FebriDx assay. Design:: Retrospective observational cohort. Setting Large acute National Health Service hospital in London, UK. Participants: All medical admissions from the emergency department between 10 August 2020 and 4 November 2020 with a valid SARS-CoV-2 RT-PCR result. Interventions: Medical admissions were triaged as likely, possible or unlikely COVID-19 based on clinical criteria. Patients triaged as possible COVID-19 underwent FebriDx lateral flow assay on capillary blood, and those positive for myxovirus resistance protein A (a host response protein) were managed as likely COVID-19. Primary outcome measures: Diagnostic accuracy (sensitivity, specificity and predictive values) of the algorithm and the FebriDx assay using SARS-CoV-2 RT-PCR from nasopharyngeal swabs as the reference standard. Results: 4.0% (136) of 3443 medical admissions had RT-PCR confirmed COVID-19. Prevalence of COVID-19 was 46% (80/175) in those triaged as likely, 4.1% (50/1225) in possible and 0.3% (6/2033) in unlikely COVID-19. Using a SARS-CoV-2 RT-PCR reference standard, clinical triage had sensitivity of 96% (95% CI 91% to 98%) and specificity of 61.5% (95% CI 59.8% to 63.1%), while the triage algorithm including FebriDx had sensitivity of 93% (95% CI 87% to 96%) and specificity of 86.4% (95% CI 85.2% to 87.5%). While 2033 patients were deemed not to require isolation using clinical criteria alone, the addition of FebriDx to clinical triage allowed a further 826 patients to be released from isolation, reducing the need for isolation rooms by 9.5 per day, 95% CI 8.9 to 10.2. Ten patients missed by the algorithm had mild or asymptomatic COVID-19. Conclusions: A triage algorithm including the FebriDx assay had good sensitivity and was useful to ‘rule-out’ COVID-19 among medical admissions to hospital

Derivation of phenotypically diverse neural culture from hESC by combining adherent and dissociation methods

Background:Differentiation of human embryonic stem cells (hESCs) into distinct neural lineages has been widely studied. However, preparation of mixed yet neurochemically mature populations, for the study of neurological diseases involving mixed cell types has received less attention.New method:We combined two commonly used differentiation methods to provide robust and reproducible cultures in which a mixture of primarily GABAergic and Glutamatergic neurons was obtained. Detailed characterisation by immunocytochemistry (ICC) and quantitative real-time PCR (qPCR) assessed the neurochemical phenotype, and the maturation state of these neurons.Results:We found that once neurospheres (NSs) had attached to the culture plates, proliferation of neural stem cell was suppressed. Neuronal differentiation and synaptic development then occurred after 21 days in vitro (DIV). By 49DIV, there were large numbers of neurochemically and structurally mature neurons. The qPCR studies indicated that expression of GABAergic genes increased the most (93.3-fold increase), followed by glutamatergic (51-fold increase), along with smaller changes in expression of cholinergic (3-fold increase) and dopaminergic genes (6-fold increase), as well as a small change in glial cell marker expression (5-fold increase).Comparison with existing method (s):Existing methods isolate hESC-derived neural progenitors for onward differentiation to mature neurons using either migration or dissociative paradigms. These give poor survival or yield. By combining these approaches, we obtain high yields of morphologically and neurochemically mature neurons. These can be maintained in culture for extended periods.Conclusion:Our method provides a novel, effective and robust neural culture system with structurally and neurochemically mature cell populations and neural networks, suitable for studying a range of neurological diseases from a human perspective

Enteric Neurospheres Are Not Specific to Neural Crest Cultures: Implications for Neural Stem Cell Therapies

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited