215 research outputs found
Study of the requirements of an autonomous system for surface water quality monitoring
In recent years, there has been increasing awareness of the preservation, protection and sustainable use of natural resources. Water resources, being one of the most important natural resources, face major threats due to contamination by pollutants of various types and origins. Maintaining the quality of water resources requires more robust, reliable and more frequent monitoring than traditional techniques of data collection based on sporadic, discontinuous and manual processes. The management of large geographical areas, the insufficient spatiotemporal discretization of the values of samples collected by traditional processes and the unpredictability of natural phenomena, require a new approach to data collection procedures. This article, which is the result of ongoing research, defines the technical requirements and technologies used in a continuous and regular monitoring of surface water quality in freshwater systems, whose data acquisition system helps to identify the sources of pollution and the contaminants flow along the waterways. The design of a versatile real-time water quality monitoring system, which, due to its environmental constraints should be based on renewable energies and wireless transfer of energy, will contribute to improve the management and effective protection of water resources.This work was supported by Centro2020, Portugal 2020 and European Union (EU) under the grants, CENTRO-01-0145-FEDER-024052E – Libélula: Mobile robotic surface water quality monitoring system.info:eu-repo/semantics/publishedVersio
Oxygen transport in Ce0.8Gd0.2O2 - δ-based composite membranes
Gadolinia-doped ceria electrolyte Ce0.8Gd0.2O2 - δ (CGO) and perovskite-type mixed conductor La0.8Sr0.2Fe0.8Co0.2O3 - δ (LSFC), having compatible thermal expansion coefficients (TECs), were combined in dual-phase ceramic membranes for oxygen separation. Oxygen permeability of both LSFC and composite LSFC/CGO membranes at 970-1220 K was found to be limited by the bulk ambipolar conductivity. LSFC exhibits a relatively low ionic conductivity and high activation energy for ionic transport (∼ 200 kJ/mol) in comparison with doped ceria. As a result, oxygen permeation through LSFC/CGO composite membranes, containing similar volume fractions of the phases, is determined by the ionic transport in CGO. The permeation fluxes through LSFC/CGO and La0.7Sr0.3MnO3 - δ/Ce0.8Gd0.2O2 - δ (LSM/CGO) composites have comparable values. An increase in the p-type electronic conductivity of ceria in oxidizing conditions, which can be achieved by co-doping with variable-valence metal cations, such as Pr, leads to a greater permeability. The oxygen ionic conductivity of the composites consisting of CGO and perovskite oxides depends strongly of processing conditions, decreasing with interdiffusion of the phase components, particularly lanthanum and strontium cations from the perovskite into the CGO phase
ORIGEM E RAMIFICAÇÕES DAS ARTÉRIAS MESENTÉRICAS CRANIAL E CAUDAL EM TARTARUGA DA AMAZÔNIA Podocnemis expansa Schweigger, 1812, (Testudinata-pelomedusidae)
Foram estudadas cinco Podocnemis expansa, fêmeas, cujo peso variava de 550 a 850 g. Os
animais tiveram seu sistema arterial injetado com solução corada de látex sintético, fixados e armazenados
em solução aquosa de formaldeído a 10%. Após abertura da cavidade celomática, as artérias mesentéricas
cranial e caudal foram dissecadas. Encontrou-se a artéria mesentérica cranial como um ramo do tronco
celíaco-mesentérico e originando as artérias pancreaticoduodenal caudal, ileocólica e jejunais, que irrigam
o duodeno, pâncreas, cólon, íleo e jejuno, respectivamente. A artéria mesentérica caudal origina-se da
aorta (60%) ou da artéria ilíaca comum (40%), distribuindo-se para o cólon e reto.
Origin and ramifications of the cranial and caudal mesenteric arteries in Amazonian
turtle - Podocnemis expansa Schweigger, 1812, Testudinata-Pelomedusidae
Abstract
An anatomic study has been carried out on the mesenteric arteries of five Podocnemis
expansa females weighing from 550 to 680 g. The animals had their artery system injected with a latex
solution colored with a specific pigment and were then fixed in a 10% formol solution. After the coelomatic
cavity being opened the cranial and caudal mesenteric arteries were dissected. It has been found that
the cranial mesenteric artery is a branch of the coeliac mesenteric trunk while the cranial mesenteric
artery gives off the pancreatic-duodenal , ileocolic and jejunal arteries that irrigate the duodenum,
pancreas, colon, ileum and jejunum respectively. The aorta gives origen of as much as 60% of the
caudal mesenteric artery, the remaining 40 % being originated from the common ileac artery, their
branches reaching the colon and the rectum
Dysregulated autoantibodies targeting vaso- and immunoregulatory receptors in Post COVID Syndrome correlate with symptom severity
Most patients with Post COVID Syndrome (PCS) present with a plethora of symptoms without clear evidence of organ dysfunction. A subset of them fulfills diagnostic criteria of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Symptom severity of ME/CFS correlates with natural regulatory autoantibody (AAB) levels targeting several G-protein coupled receptors (GPCR). In this exploratory study, we analyzed serum AAB levels against vaso- and immunoregulatory receptors, mostly GPCRs, in 80 PCS patients following mild-to-moderate COVID-19, with 40 of them fulfilling diagnostic criteria of ME/CFS. Healthy seronegative (n=38) and asymptomatic post COVID-19 controls (n=40) were also included in the study as control groups. We found lower levels for various AABs in PCS compared to at least one control group, accompanied by alterations in the correlations among AABs. Classification using random forest indicated AABs targeting ADRB2, STAB1, and ADRA2A as the strongest classifiers (AABs stratifying patients according to disease outcomes) of post COVID-19 outcomes. Several AABs correlated with symptom severity in PCS groups. Remarkably, severity of fatigue and vasomotor symptoms were associated with ADRB2 AAB levels in PCS/ME/CFS patients. Our study identified dysregulation of AAB against various receptors involved in the autonomous nervous system (ANS), vaso-, and immunoregulation and their correlation with symptom severity, pointing to their role in the pathogenesis of PCS
Avaliação do desempenho de um aquecedor para aves adaptado para utilizar biogás como combustível
Genotyping and antimicrobial susceptibility of Clostridium perfringens isolated from Tinamidae, Cracidae and Ramphastidae species in Brazil
"Tomography" of the cluster structure of light nuclei via relativistic dissociation
These lecture notes present the capabilities of relativistic nuclear physics
for the development of the physics of nuclear clusters. Nuclear track emulsion
continues to be an effective technique for pilot studies that allows one, in
particular, to study the cluster dissociation of a wide variety of light
relativistic nuclei within a common approach. Despite the fact that the
capabilities of the relativistic fragmentation for the study of nuclear
clustering were recognized quite a long time ago, electronic experiments have
not been able to come closer to an integrated analysis of ensembles of
relativistic fragments. The continued pause in the investigation of the "fine"
structure of relativistic fragmentation has led to resumption of regular
exposures of nuclear emulsions in beams of light nuclei produced for the first
time at the Nuclotron of the Joint Institute for Nuclear Research (JINR,
Dubna). To date, an analysis of the peripheral interactions of relativistic
isotopes of beryllium, boron, carbon and nitrogen, including radioactive ones,
with nuclei of the emulsion composition, has been performed, which allows the
clustering pattern to be presented for a whole family of light nuclei.Comment: ISBN 978-3-319-01076-2. 55 pages, 28 figure
Efeitos da terra diatomácea sobre Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae) em batata inglesa
Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World.
Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites
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