187 research outputs found
Trees and shrubs as sources of fodder in Australia
Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline
Intra-hospital transport of neonatal intensive care patients: risk factors for complications
OBJECTIVE: Evaluate factors associated with hypothermia and increased need of oxygen and/or ventilatory support during intra-hospital transport of neonatal intensive care patients. METHODS: Prospective study of infants admitted to a single neonatal unit in need of at least one intra-hospital transport during weekdays, from 8:00AM to 05:00PM, from January 1997 to December 2000. Factors associated with hypothermia and increased need of oxygen and/or need of ventilatory support during and up to two hours after transport were studied by regression analyses. RESULTS: During the study period, 502 transports were analyzed. At the time of transport, the neonates had a mean weight and gestational age of, respectively, 2,000g and 35 weeks, and they were 22 days old. The main reasons for transport were: surgery and image exams. Hypothermia occurred in 17% of the transported infants and increased need of oxygen and/or ventilatory support in 7%. Factors associated with hypothermia were: duration of transportation >3h (OR=2.1; 95%CI=1.2-3.6), neurologic malformation (OR=1.7; 95%CI=1.1-2.5), transport performed in 1997 (OR=1.7; 95%CI=1.1-2.6) and weight at time of transport >3,500g (OR=0.3; 95%CI=0.16-0.68). Factors associated with increased need of oxygen and/or ventilation support were: gestational age at birth in weeks (OR=0.9; 95%CI=0.8-0.9), age in days at transportation (OR=1.0; 95%CI=1.0-1.1) and presence of gastrointestinal and genitourinary malformation (OR=3.1; 95%CI=1.6-6.2). CONCLUSIONS: Complications related to neonatal intra-hospital transports are frequent and associated with the patients characteristics and transport conditions.OBJETIVO: Estudar os fatores associados à hipotermia e ao aumento da necessidade de oxigênio e/ou suporte ventilatório durante o transporte intra-hospitalar de pacientes internados em Unidade de Terapia Intensiva neonatal. MÉTODOS: Estudo prospectivo de todos os pacientes internados na unidade neonatal que necessitaram de transporte intra-hospitalar de janeiro de 1997 a dezembro de 2000, entre segundas-feiras e sextas-feiras, das 8h às 17h. Fatores associados à hipotermia e ao aumento da necessidade de oxigênio e/ou de suporte ventilatório durante e até duas horas após o transporte foram estudados por meio de regressão logística. RESULTADOS: Foram realizados 502 transportes no período. Os pacientes tinham em média 2.000g, 35 semanas de idade gestacional ao nascer e 22 dias de vida. As principais indicações do transporte foram: cirurgia e realização de exames de imagem. A hipotermia ocorreu em 17% dos transportes e o aumento da necessidade de oxigênio e/ou de suporte ventilatório em 7%. Fatores associados à hipotermia foram: duração do transporte >3h (OR=2,1; IC95%=1,2-3,6), presença de malformações neurológicas (OR=1,7; IC95%=1,1-2,5), transporte realizado em 1997 (OR=1,7; IC95%=1,1-2,6) e peso no transporte >3.500g (OR=0,3; IC95%=0,16-0,68). Fatores de risco para o aumento da necessidade de oxigênio e/ou de suporte ventilatório foram: idade gestacional ao nascimento em semanas (OR=0,9; IC95%=0,8-0,9), idade em dias no transporte (OR=1,0; IC95%=1,0-1,1) e presença de malformações gastrintestinais e geniturinárias (OR=3,1; IC95%=1,6-6,2). CONCLUSÕES: As intercorrências relativas ao transporte intra-hospitalar são freqüentes nos neonatos em UTI e estão associadas às condições dos pacientes e dos transportes.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUNIFESP-EPM Departamento de PediatriaUNIFESP-EPM Departamento de Medicina PreventivaUNIFESP, EPM, Depto. de PediatriaUNIFESP, EPM Depto. de PediatriaUNIFESP, EPM Depto. de Medicina PreventivaSciEL
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Corporate tax: what do stakeholders expect?
Motivated by the ongoing controversy surrounding corporate tax, this article presents a study that explores stakeholder expectations of corporate tax in the context of UK business. We conduct a qualitative analysis of in-depth interviews with representatives of community groups (NGOs/think tanks and special interest groups), as well as interviews with those representing business groups (business leaders and industry representatives). We then identify eight themes that together describe “what” companies need to do, “how” they need to do it, and “why” they need to do it, if they wish to appeal to a wide group of interested parties. We discuss our findings based on the corporate social responsibility literature and propose novel ways for community groups and business groups to connect on the topic of corporate tax, suggesting opportunities and themes for dialogue and potential steps to co-create solutions in a stakeholder society
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Exploring new physics frontiers through numerical relativity
The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology
Genetic epidemiology of SARS-CoV-2 transmission in renal dialysis units - a high risk community-hospital interface
OBJECTIVES: Patients requiring haemodialysis are at increased risk of serious illness with SARS-CoV-2 infection. To improve the understanding of transmission risks in six Scottish renal dialysis units, we utilised the rapid whole-genome sequencing data generated by the COG-UK consortium. METHODS: We combined geographical, temporal and genomic sequence data from the community and hospital to estimate the probability of infection originating from within the dialysis unit, the hospital or the community using Bayesian statistical modelling and compared these results to the details of epidemiological investigations. RESULTS: Of 671 patients, 60 (8.9%) became infected with SARS-CoV-2, of whom 16 (27%) died. Within-unit and community transmission were both evident and an instance of transmission from the wider hospital setting was also demonstrated. CONCLUSIONS: Near-real-time SARS-CoV-2 sequencing data can facilitate tailored infection prevention and control measures, which can be targeted at reducing risk in these settings
Genetic Determinants of Time Perception Mediated by the Serotonergic System
Background: The present study investigates neurobiological underpinnings of individual differences in time perception. Methodology: Forty-four right-handed Russian Caucasian males (18–35 years old) participated in the experiment. The polymorphism of the genes related to the activity of serotonin (5-HT) and dopamine (DA)-systems (such as 5-HTT, 5HT2a, MAOA, DAT, DRD2, COMT) was determined upon the basis of DNA analysis according to a standard procedure. Time perception in the supra-second range (mean duration 4.8 s) was studied, using the duration discrimination task and parametric fitting of psychometric functions, resulting in individual determination of the point of subjective equality (PSE). Assuming the ‘dual klepsydra model ’ of internal duration representation, the PSE values were transformed into equivalent values of the parameter k (kappa), which is a measure of the ‘loss rate ’ of the duration representation. An association between time representation parameters (PSE and k, respectively) and 5-HT-related genes was found, but not with DArelated genes. Higher ‘loss rate ’ (k) of the cumulative duration representation were found for the carriers of genotypes characterized by higher 5-HT transmission, i.e., 1) lower 5-HT reuptake, known for the 5-HTTLPR SS polymorphism compared with LL, 2) lower 5-HT degradation, described for the ‘low expression ’ variant of MAOA VNTR gene compared with ‘high expression ’ variant, and 3) higher 5-HT2a receptor density, proposed for the TT polymorphism of 5-HT2a T102C gene compared with CC
Brain injury-associated biomarkers of TGF-beta1, S100B, GFAP, NF-L, tTG, AbetaPP, and tau were concomitantly enhanced and the UPS was impaired during acute brain injury caused by Toxocara canis in mice
BACKGROUND: Because the outcomes and sequelae after different types of brain injury (BI) are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs), including transforming growth factor beta1 (TGF-beta1), S100B, glial fibrillary acidic protein (GFAP), neurofilament light chain( NF-L), tissue transglutaminases (tTGs), beta-amyloid precursor proteins (AbetaPP), and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS) is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae of Toxocara canis can invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT). Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT. METHODS: BIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250 T. canis embryonated eggs was investigated from 3 days (dpi) to 8 weeks post- infection (wpi) by Western blotting and RT-PCR. RESULTS: Results revealed that at 4 and 8 wpi, T. canis larvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-beta1, S100B, NF-L, tTG, AbetaPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain. CONCLUSION: Further studies are needed to determine whether there is an increased risk of CT progression into neurodegenerative disease because neurodegeneration-associated AbetaPP and phosphorylated tau emerged in the brain. DOI: 10.1186/1471-2334-8-8
Localized induction of gene expression in embryonic stem cell aggregates using holographic optical tweezers to create biochemical gradients
Three-dimensional (3D) cell models that mimic the structure and function of native tissues are enabling more detailed study of physiological and pathological mechanisms in vitro. We have previously demonstrated the ability to build and manipulate 3D multicellular microscopic structures using holographic optical tweezers (HOTs). Here, we show the construction of a precisely patterned 3D microenvironment and biochemical gradient model consisting of mouse embryoid bodies (mEBs) and polymer microparticles loaded with retinoic acid (RA), embedded in a hydrogel. We demonstrate discrete, zonal expression of the RA-inducible protein Stra8 within mEBs in response to release of RA from polymer microparticles, corresponding directly to the defined 3D positioning of the microparticles using HOTs. These results demonstrate the ability of this technology to create chemical microgradients at definable length scales and to elicit, with fidelity and precision, specific biological responses. This technique can be used in the study of in vitro microenvironments to enable new insights on 3D cell models, their cellular assembly, and the delivery of drug or biochemical molecules for engineering and interrogation of functional and morphogenic responses
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