3,874 research outputs found
Design of a Base-Board for arrays of closely-packed Multi-Anode Photo-Multipliers
We describe the design of a Base-Board to house Multi-Anode Photo-Multipliers
for use in large-area arrays of light sensors. The goals, the design, the
results of tests on the prototypes and future developments are presented.Comment: 16 pages, 5 figures, submitted to Nucl. Instrum. and Meth.
ESTUDO DA QUALIDADE DAS ÁGUAS SUPERFICIAIS E SUBSUPERFICIAIS DA VÁRZEA LITORÂNEA DO SURUACA, REGIÃO NORTE DO ESTADO DO ESPÍRITO SANTO
Esta dissertação analisa quais parâmetros podem,
efetivamente, estar contribuindo para a alteração da qualidade
das águas na várzea litorânea da região do Suruaca,
no norte do Espírito Santo. É desenvolvida tendo por base
alguns resultados de campanhas de monitoramento já
executadas e algumas em execução nas águas superficiais
e subsuperficiais da região. É uma área plana e
baixa, com o nível do lençol freático próximo à superfície,
altamente desmatada, na qual há uma dominância de
atividades tais como pecuária extensiva, plantio de
eucaliptos e exploração e produção de petróleo. As campanhas
de monitoramento da qualidade das águas que
têm sido executadas compreendem 27 parâmetros no
total, e algumas anomalias têm sido registradas. Os dados
são plotados em Excel ® , de modo a descobrir anomalias
em relação a estes referenciais. Os parâmetros
têm também suas características estudadas por meio
de pesquisa bibliográfica. Para ser considerada anomalia
a concentração média do parâmetro tem que estar
em desacordo com a legislação, neste caso a Resolução
Conama 20/86. Também são considerados como anomalias
os parâmetros cujas concentrações médias a
jusante são maiores do que a montante. Por meio de
consulta à bibliografia e entrevistas com pessoas com
conhecimento da região, as principais atividades econômicas
presentes são definidas, assim como as matérias-
primas e insumos utilizados por elas. Estes materiais
são analisados utilizando-se ensaios de lixiviação,
de solubilização, difratometria por raios-X e fluorescência
de raios-X, desta forma, tenta-se encontrar correlações
entre parâmetros com concentrações anômalas e atividades
econômicas. Além de fatores de origem
antropogênica, há fontes naturais que também contribuem
para alterações na qualidade das águas da região.
Esta dissertação chega à conclusão que nem todos
os parâmetros analisados necessitariam de uma
continuidade de monitoramento, visto que tanto as características
das atividades econômicas na área de estudo
como os resultados dos monitoramentos permitem
chegar a esta conclusão. Por ouro lado, há outros
parâmetros que demandam pesquisas mais profundas,
visto que eles ocorrem em concentrações maiores do
que esperado. Para estes parâmetros são relacionadas,
quando possível, as atividades mais prováveis de estar
contribuindo para suas ocorrências com concentrações
acima dos níveis permitidos. Não é possível avaliar a
origem das concentrações anômalas para bário, chumbo
e mercúrio
Occurrence of Blastocystis-subtypes in patients from Italy revealed association of ST3 with a healthy gut microbiota
An epidemiological survey on Blastocystis was carried out enrolling a total of 2524 subjects referred to the Umberto I Academic Hospital in Rome, for the routine parasitological exams, during 2017–2018. The studied population included a sample of immunocompromised individuals (N = 130) followed at the same hospital. DNA sequencing of the small subunit rRNA gene (SSU rDNA) locus was performed on samples positive to the coproparasitological analysis to molecular characterize the Blastocystis-subtypes. Microscopical analysis detected Blastocystis in 192/2524 (7.6%) of the enrolled subjects. It was the organism most frequently identified in the analysed faecal samples diagnosed in single infection (5.6%) or in co-infection with other enteric protozoa (2%). Furthermore, it was found mainly in immunocompromised patients (22.3%) compared to immunocompetent ones (6.8%). As expected, ST3 was the most occurring subtype identified in 40% of the subjects, followed by ST1 (29%), ST2 (16%), ST4 (12%), and ST7 (3%). Next-generation sequencing (NGS) of the 16S rDNA was performed on a sub-sample of Blastocystis-ST3-carriers, homogenous by age and gender, as well as on Blastocystis-free subjects, to profile and compare their gut bacterial composition. A higher bacterial diversity was found in ST3-Blastocystis-carriers, which exhibited a high abundance of Prevotella, Methanobrevibacter and Ruminococcus while, a high percentage of Bacteroides was found in Blastocystis-free subjects. This study evidenced the presence of Blastocystis in 7.6% of faecal samples in Italy and a high circulation of the protist among immunocompromised patients (22.3%). Molecular characterization of positive samples evidenced the occurrence of five different subtypes, including zoonotic ST such as the ST7, highlighting the risk of transmission from animals. Study of the gut microbiota composition confirms previous evidences according to which, the colonisation by Blastocystis would be linked with an eubiotic gut characterized by potentially beneficial species such as Prevotella and Ruminococcus, rather than with a dysbiotic state, with a high abundance of Enterobacteriaceae, and corroborated the role of the protist as “an old friend” of the human gut
Portable dVRK: an augmented V-REP simulator of the da Vinci Research Kit
The da Vinci Research Kit (dVRK) is a first generation da Vinci robot repurposed as a research platform and coupled with software and controllers developed by research users. An already quite wide community is currently sharing the dVRK (32 systems in 28 sites worldwide). The access to the robotic system for training surgeons and for developing new surgical procedures, tools and new control modalities is still difficult due to the limited availability and high maintenance costs. The development of simulation tools provides a low cost, easy and safe alternative to the use of the real platform for preliminary research and training activities. The Portable dVRK, which is described in this work, is based on a V-REP simulator of the dVRK patient side and endoscopic camera manipulators which are controlled through two haptic interfaces and a 3D viewer, respectively. The V-REP simulator is augmented with a physics engine allowing to render the interaction of new developed tools with soft objects. Full integration in the ROS control architecture makes the simulator flexible and easy to be interfaced with other possible devices. Several scenes have been implemented to illustrate performance and potentials of the developed simulator
Innovative crop and weed management strategies for organic spinach: crop yield and weed suppression.
In organic agriculture, it is important to tackle crop and weed management from a system perspective to make it effective, especially in poorly competitive crops such as vegetables. For that reason, we developed two innovative integrated crop and weed management systems for a field vegetable crop sequence in a commercial organic farm that we have been comparing to a standard farm system from 2006 to 2008. The three systems are applied to a spinach-potato-cabbage-tomato two-year crop sequence and include different levels of technical innovation: Standard Crop Management System (SCMS); Intermediate Crop Management System (ICMS); and Advanced Crop Management System (ACMS). ICMS is based on a sequence of physical weed management treatments, whereas ACMS also includes a subterranean clover (Trifolium subterraneum) living mulch. In this paper we analyse the results obtained on spinach (Spinacia oleracea) in terms of crop yield and weed suppression. Both innovative systems increased total spinach fresh weight yield compared to SCMS, despite higher weed biomass. In ACMS, total weed biomass decreased linearly with increasing biomass of the subterranean clover living mulch
CYP17A1 polymorphism c.-362T>C predicts clinical outcome in metastatic castration-resistance prostate cancer patients treated with abiraterone
Background: Abiraterone became a standard hormonal therapy for patients with metastatic castration-resistance prostate cancer (mCRPC). However, patients may experience primary resistance to treatment. To date, few predictive biomarkers of efficacy have been identified. Our aim was to investigate the association between the single nucleotide polymorphism (SNP) c.-362T>C in the CYP17A1 gene, and clinical outcome in mCRPC patients treated with abiraterone. Patients and methods: mCRPC patients candidate to receive abiraterone were enrolled in the present retrospective pharmacogenetic study. Based on a literature selection, CYP17A1 rs2486758 (c.-362T > C) was selected and analysed by real-time PCR on genomic DNA extracted from whole blood. Univariate analysis was performed to test the association between the SNP and treatment-related clinical outcomes. Results: Sixty mCRPC patients were enrolled in the present study. Patients carrying the mutant CYP17A1 c.-362CT/CC genotypes showed a shorter median progression-free survival (PFS) and prostate-specific antigen-PFS (PSA-PFS) compared to patients carrying the TT genotype (10.7 vs 14.2 months and 8 vs 16 months, respectively; p = 0.04). No association between the selected SNP and the overall survival was found. Conclusions: These findings suggest an association between CYP17A1 c.-362T>C polymorphism and poorer clinical outcome with abiraterone for mCRPC patients. However, further validations on larger cohort of patients are needed to confirm its role as a predictive biomarker for abiraterone resistance
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