6,743 research outputs found
Diversidade de rizóbios em áreas revegetadas após a mineração de bauxita.
A contribuição da diversidade dos rizóbios para manutenção da diversidade e funcionalidade de ecossistemas naturais tem sido pouco estudada. Neste trabalho objetivou-se avaliar a diversidade de rizóbios em áreas revegetadas em diferentes épocas. Utilizou-se siratro e mimosa como plantas-isca e as ferramentas PCR-RFLP, sequencimanto e BOX-PCR. Observou-se que as áreas de maior diversidade foram as revegetadas há mais tempo e as áreas revegetadas com plantio da leguminosa Acacia mangium e, que isolados proximamente relacionados ao gênero Bradyrhizobium foram os mais abundantes
Genetic diversity of Lusitano horse in Brazil using pedigree information
This study aimed to evaluate population parameters and to describe the genetic diversity of the Lusitano
breed in Brazil using pedigree data. Two populations were evaluated: total population (TP) containing
18,922 animals, and reference population (RP) composed of a part of TP containing 8,329 animals, representing
the last generation. The generation interval (10.1 ± 5.1 years) was in the range for horse populations.
Pedigree completeness in RP shows almost 100% filling in the three most recent generations,
indicating improvement in the pedigree data and accuracy of the results, and the inbreeding coefficient
(4.46%) and average relatedness (5.97%) for RP, indicating control on the part of breeders. The effective
population size was 89 (TP) and 90 (RP). The effective number of founders (fe) were 33 and 29, effective
number of ancestors (fa) were 30 and 26, and effective number of founder genomes (fg) were 19 and 15 for
TP and RP, respectively, indicating a reduction of genetic variability in the last generations. The total
number of ancestors that explains 100% of the genetic diversity in the Lusitano breed in Brazil was 427 (TP)
and 341 (RP). The reproductive parameters, probabilities of gene origin showing loss of variability in the
last generations, and the genetic contributions of ancestors suggest the need to monitor genetic diversity
over time in breeding programs to allow control of the next generations and to increase their variability.info:eu-repo/semantics/publishedVersio
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
Inteligência artificial aplicada à predicação do ponto de abate de bovinos confinados.
O objetivo deste trabalho foi criar um software para realizar a predição do ponto de abate de bovinos por meio de caracterÃsticas e medidas ultrassonográficas obtidas apenas no inÃcio do confinamento
Distinguishing the albedo of exoplanets from stellar activity
Light curves show the flux variation from the target star and its orbiting
planets as a function of time. In addition to the transit features created by
the planets, the flux also includes the reflected light component of each
planet, which depends on the planetary albedo. This signal is typically
referred to as phase curve and could be easily identified if there were no
additional noise. As well as instrumental noise, stellar activity, such as
spots, can create a modulation in the data, which may be very difficult to
distinguish from the planetary signal. We analyze the limitations imposed by
the stellar activity on the detection of the planetary albedo, considering the
limitations imposed by the predicted level of instrumental noise and the short
duration of the observations planned in the context of the CHEOPS mission. As
initial condition, we have assumed that each star is characterized by just one
orbiting planet. We built mock light curves that included a realistic stellar
activity pattern, the reflected light component of the planet and an
instrumental noise level, which we have chosen to be at the same level as
predicted for CHEOPS. We then fit these light curves to try to recover the
reflected light component, assuming the activity patterns can be modeled with a
Gaussian process.We estimate that at least one full stellar rotation is
necessary to obtain a reliable detection of the planetary albedo. This result
is independent of the level of noise, but it depends on the limitation of the
Gaussian process to describe the stellar activity when the light curve
time-span is shorter than the stellar rotation. Finally, in presence of typical
CHEOPS gaps in the simulations, we confirm that it is still possible to obtain
a reliable albedo.Comment: Accepted for publication in A&A, 14 pages, 12 figure
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
Análise cientométrica da atividade cientÃfica na área de solos: o caso da América Latina.
Os indicadores cientométricos em Ciência e Tecnologia surgem da necessidade mensuração da produção cientÃfica, partindo-se da premissa de que a ciência se encontra, em grande parte, incorporada em sua literatura. Sendo assim este estudo se insere nesse contexto, ao utilizar a Cientometria para mapear a produção cientÃfica na área de solos, área do conhecimento que tem se destacado devido à sua atuação fundamental na agricultura e, mais recentemente, em temas da agenda global de manejo e uso sustentável dos recursos naturais. O método empregado foi a análise bibliométrica automatizada em registros extraÃdos da base de dados Scopus, no perÃodo de 1999-2010. Os resultados demonstram a importância da disciplina no meio cientÃfico, ao comprovar o crescimento do número de artigos publicados, de temas envolvidos, dos principais periódicos e das instituições de pesquisa que se destacam na produção de conhecimento em solo na América Latina.bitstream/item/63701/1/BPD-172-Analise-cientometrica.pd
Plant-nematode co-cultures in the screening of sustainable nematicides against soil-dwelling parasitic nematodes of plants
The diseases caused by plant parasitic nematodes are still a serious constraint to modern global crop production. An
increasing number of active compounds in commercial nematicidal formulations is being banned from use by common
policies of pest management. Farmer communities report a low efficiency for the replacement pesticides, which reflects
on crop yield and productivity. Novel sustainable biopesticides are urgently needed to cope with global food demands
while respecting the most recent environmental policies. Plant-nematode co-cultures offer a stable biotechnological
screening tool able to assess the active compound’s nematicidal activity and its effect on host tissues, simultaneously,
in an easily accessible system that simulates natural infection. These systems are being developed and optimized at the
Nematology laboratory of INIAV. Preliminary results were obtained for co-cultures of Solanum lycopersicum with the
nematode Meloidogyne ethiopica and S. tuberosum with Globodera pallida. Future studies will target other plant parasitic
nematodes, e.g., the root lesion nematodes (Pratylenchus penetrans) in transgenic roots of potato and the pinewood
nematode (Bursaphelenchus xylophilus) on in vitro pine shoots (Pinus sp.)
Comparing continuous lumbar plexus block, continuous epidural block and continuous lumbar plexus block with a parasacral sciatic nerve block on post-operative analgesia after hip arthroplasty
Study Objective: To compare post-operative analgesia obtained by continuous lumbar epidural block (CLEB) versus continuous lumbar plexus block (CLPB) versus CLPB associated with a single shot parasacral sciatic nerve block (CLEBS) after total hip arthroplasty (THA).
Study design: Randomized clinical trial.
Setting: Operating room, postoperative care unit, orthopedic surgical ward.
Methods: 78 ASA I-III patients undergoing elective THA were randomly assigned to receive CLEB (n=24, 15-20 ml of 5 mg/ml ropivacaine, sufentanil 10 mg, clonidine 1 mg/ml), CLPB (n=22, 3mg/kg of 5 mg/ml of ropivacaine, max. 40 ml, clonidine 1 mg/ml, sufentanil 10 mg) or CLPBS (n=23, CLPB as described above; sciatic nerve: 20 ml of ropivacaine 5 mg/ml, clonidine 1 mg/ml). All patients received continuous infusion of 2 mg/ml of ropivacaine, 8 ml/h for 48 hours. Primary outcome was pain intensity assessment (VAS and VS). Secondary outcomes were postoperative total opioid consumption, hemodynamic stability, motor blockade, blood loss, intraoperative sufentanil and propofol consumption, patient satisfaction and complications.
Results: VAS was lower in the CLEB group than in the CLPB and CLPBS groups respectively for 6 and 12 hours postoperatively (post-surgery p<0.001, 2h p<0.001, 6h p<0.001, 12h p<0.03)(Table 2). Moreover, CLPSB patients reported lower VAS than CLPB patients from the end of the surgery till the 12th follow up hour (Table 2). VS was lower in the CLEB group from the end of surgery to 6h postoperatively (Table 3). The CLPB group showed higher morphine consumption than the CLPSB and CLEB groups over 12 h postoperatively (p=0.05); thereafter, no statistically significant diferences were observed between groups at the end of follow up (48h) (p=0.4) (Table 4).
onclusion: In conclusion, continuous lumbar plexus block in association with single shot sciatic nerve block is a valid alternative to epidural technique in managing postoperative analgesia after THA, with an improved risk-benefit balanc
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