Currents and pseudomagnetic fields in strained graphene rings

We study the effects of strain on the electronic properties and persistent current characteristics of a graphene ring using the Dirac representation. For a slightly deformed graphene ring flake, one obtains sizable pseudomagnetic (gauge) fields that may effectively reduce or enhance locally the applied magnetic flux through the ring. Flux-induced persistent currents in a flat ring have full rotational symmetry throughout the structure; in contrast, we show that currents in the presence of a circularly symmetric deformation are strongly inhomogeneous, due to the underlying symmetries of graphene. This result illustrates the inherent competition between the `real' magnetic field and the `pseudo' field arising from strains, and suggest an alternative way to probe the strength and symmetries of pseudomagnetic fields on graphene systems

Neonatal Appendicitis – an Uncommon Diagnosis, not to be Forgotten

Acute appendicitis is a common disease in older children, but extremely rare in the neonate. Nevertheless, the true incidence might be underestimated, given the difficulty of the diagnosis. Subtle clinical signs and symptoms usually result in high morbidity and mortality due to delayed diagnosis and surgical intervention. The presentation of neonatal appendicitis can be identical to necrotizing enterocolitis, leading to misdiagnosis. Appendicitis should therefore be considered in the differential diagnosis for necrotizing enterocolitis and needs strong clinical suspicion. We report a case of a premature newborn who presented with vomiting, abdominal distension and free intra-peritoneal air on plain x-ray. He was initially diagnosed and treated as necrotizing enterocolitis, but the absence of clinical improvement with standard treatment led to exploratory laparotomy. Surgical exploration revealed an acutely inflamed appendix with normal small and large intestines and appendectomy was performed. The post-operatory period was uneventful and the infant was discharged home. Follow-up confirmed a normal growth and neurodevelopment. We herein report this case in order to raise awareness to this unusual pathology, so that an early diagnosis and treatment can lead to a better outcome, improving survival rate and reducing long term morbidity. We believe uncommon pathologies, like neonatal appendicitis, should be reported to facilitate proper epidemiologic studies

Finding Out The Neurological Consequences Of Covid-19

t- Introduction: Since the first official case of COVID-19 in China in December 2019, researchers have been trying to uncover the mechanism of action of the severe acute respiratory syndrome Coronavirus 2 (Sars-CoV-2), which attacks several organs in addition to the lungs and causes circulatory changes that can lead to death not only from lung failure but also due to commitment of other organs. Objective: The aim of this study is to find out the neurological consequences of COVID-19. Material and methods: A systematic review of the literature was concretised by mobilizing the descriptors: "Sars-Cov-2", "coronavirus infections" and "Neurological Consequences". Databases were selected and seven articles were included for analysis. Results and discussion: Although the effects of Sars-CoV-2 on the lung are exemplary and frightening, the long-term effects on the nervous system may be greater and even more overwhelming, as the regeneration of nerve tissue is difficult and can lead to general disability, as the nervous system coordinates the functions of the entire body. All studies show the presence of any kind of injury (mild or severe) to Central Nervous System, but some of them highlight the need for further studies to have great certainty. Conclusion: It can be said that the studies all agree on the possibility of existing neurological sequelae and a majority agree on the need for other studies.info:eu-repo/semantics/publishedVersio

Enterocolite necrosante: experiência de catorze anos

Backgound: Necrotizing enterocolitis ((NEC) is one of most frequent gastrointestinal emergencies in the neonatal period. Aims: To evaluate the incidência, epidemiology, risk factors and clinical outcomes of newborns with necrotizing enterocolitis admitted to a Level III Neonatal Intensive Care Unit (NICU) . Methods: Casuistic review of newborns with NEC adtmitted to a level III unit, from January 1995 to 31 December 2008. Results: Thirty nine patients were diagnosed: 0,8‰ of live birth, 1% of NICU admissions, 4% of very low birth weight (VLBW) and 9,5% of extremely low birth weight (ELBW) infants. Thirty eight (97%) were preterm and 85% had a gestational age (GA) of 31 weeks or less. Birth weight and GA were 1136±725g and 27,9±3,5 weeks. The prevalence for light for gestational age status was 20,5%. Forty four had blood transfusion and 36% received indomethacin treatment. Enteral feeding was started before the diagnosis of NEC in 37 (95%) newborns and 59% had breast milk feeding. NEC stage III occurred in 24 (61,5%), 67% of those had progression of milk intake < 20mg/Kg/d and 83% had rapid progression of milk intake (p=0,43). Nineteen (48,7%) were submitted to surgical intervention. The letality rate was 31%, 50% of NEC stage IIIB and 21,0% of surgical cases. Intestinal strictures and short bowel syndrome occurred in 2 cases, respectively. Conclusions: The incidence of NEC was 0,8‰ live births and 4% in VLBW. It is not possible to conclude about differences in incidence and severity of NEC with the rate of progression of milk intake

Estirpes de bactérias selecionadas para a otimização da fixação biológica de nitrogênio em leguminosas florestais .

Este comunicado apresenta resultados de pesquisas referente a seleção de estirpes em condições estéreis para Chamaecrista nictitans (L.) Moench, Mimosa pellita L. e Mimosa floculosa Burkart (etapa 2) e em condições não estéreis para Mimosa xantocentra Mart. e Erythrina falcata Benth (etapa 3). As estirpes testadas pertencem a coleção do Laboratório de Leguminosas da Embrapa Agrobiologia.bitstream/item/42764/1/COT120-09.pd

Runoff at the micro-plot and slope scale following wildfire, central Portugal

Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations. Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events

Runoff and erosion at the micro-plot and slope scale in a small burnt catchment, central Portugal

Wildfires can have important impacts on hydrological processes and soil erosion in forest catchments, due to the destruction of vegetation cover and changes to soil properties. However, the processes involved are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, especially in the up-scaling from hillslopes to catchments; in consequence, current models are poorly adapted for burnt forest conditions. The objective of this presentation is to give an overview of the hydrological response and sediment yield from the micro-plot to slope scale, in the first year following a wildfire (2008/2009) that burnt an entire catchment nearby the Colmeal village, central Portugal. The overview will focus on three slopes inside the catchment, with samples including: • Runoff at micro-plot scale (12 bounded plots) and slope scale (12 open plots); • Sediments and Organic Matter loss at micro-plot scale (12 bounded plots) and slope scale (12 open plots plus 3 Sediment fences); • Rainfall and Soil moisture data; • Soil Water Repellency and Ground Cover data. The analysis of the first year following the wildfire clearly shows the complexity of runoff generation and the associated sediment transport in recently burnt areas, with pronounced differences between hillslopes and across spatial scales as well as with marked variations through time. This work was performed in the framework of the EROSFIRE-II project (PTDC/AGR-CFL/70968/2006) which has as overall aim to predict soil erosion risk in recently burnt forest areas, including common post-fire forest management practices; the project focuses on the simultaneous measurement of runoff and soil erosion at multiple spatial scales.The results to be presented in this session are expected to show how sediment is generated, transported and exported in the Colmeal watershed; and contribute to understand and simulate erosion processes in burnt catchments, including for model development and evaluation

Estirpes de rizóbio eficientes na fixação biológica de nitrogênio para leguminosas com potencial de uso na recuperação de áreas mineradas.

Este trabalho teve como objetivo selecionar estirpes de rizóbio eficientes na fixação biológica de nitrogênio para leguminosas herbáceas de crescimento rápido e sistema radicular profuso Tephrosia adunca e Mimosa xanthocentra.bitstream/CNPAB-2010/35739/1/cot115.pdfParceria; UFRRJ