146 research outputs found
Farmer and scientific knowledge of soil quality: a social ecological soil systems approach.
This article focuses on how farmers identify and evaluate the quality of soils cultivated and how their indicators compare to those used by agricultural scientists. The aim is to bridge the gap between specific farmer knowledge and universal scientific knowledge by adopting an ecosystem framework applied to agriculture through the concept of agro-ecosystems. This approach was applied to farming in mountainous areas of the Brazilian Atlantic Forest, a global environmental hotspot that has been degraded over time. In order to reverse this trend, local actors have to build agro-ecological systems that maintain environmental quality, agronomic sustainability and socio-economic viability. For this to happen, local and scientific knowledge must be bridged and mutually adapted in order to be successful. This study therefore concentrates on processes of inter-communication between farmers and agricultural scientists concerning the role of soil quality in farming and conservation
Efficient fully blade-coated perovskite solar cells in air with nanometer-thick bathocuproine buffer layer
Fully printed perovskite solar cells (PSCs) were fabricated in air with all constituent layers, except for electrodes, deposited by the blade coating technique. The PSCs incorporated, for the first time, a nanometer-thick printed bathocuproine (BCP) hole blocking buffer using blade coating and deposited at relative humidity up to 50%. The PSCs with a p-i-n structure (glass/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/CH3NH3PbI3/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/BCP/Ag) delivered a maximum power conversion efficiency (PCE) of 14.9% on an active area of 0.5 cm2 when measured under standard test conditions. The PSCs with a blade coated BCP delivered performance of 10% and 63% higher (in relative terms) than those incorporating a spin coated BCP or without any BCP film, respectively. The atomic force microscopy (AFM) showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination. The demonstration of 15% efficient devices with all constituent layers, including nanometer-thick BCP (∼ 10 nm), deposited by blade coating in air, demonstrates a route for industrialization of this technology
Ciclooxygenase inhibitor and metronomic chemotherapy association for the treatment of metastatic anal sac carcinoma in dog: case report
ABSTRACT Metronomic chemotherapy consists of an anticancer modality treatment. It is applicable in patients at an advanced stage, with the objective of increasing overall survival. The aim of this study was to report an anal sac apocrine carcinoma case in a dog with lymph node metastasis treated with metronomic chemotherapy sequential to surgery and conventional chemotherapy using gemcitabine and carboplatin. Metronomic chemotherapy was associated with cyclooxygenase-2 (COX-2) inhibitors, due to strong tumor COX-2 immunohistochemistry expression. Metronomic chemotherapy was initiated with cyclophosphamide, but it was replaced by lomustine, also in metronomic dosage, due to adverse effects. Treatment showed effectiveness, since the patient's overall survival exceeded 1095 days (36 months), considerably higher than the mean overall survival expected for this pathology. Keywords: dog, oncology, angiogenesis inhibitor, cyclophosphamide, lomustine Palavras-chave: cão, oncologia, inibidor de angiogênese, ciclofosfamida, lomustina RESUM
Simple methodology for the quantitative analysis of fatty acids in human red blood cells
In the last years, there has been an increasing
interest in evaluating possible relations between fatty acid
(FA) patterns and the risk for chronic diseases. Due to the
long life span (120 days) of red blood cells (RBCs), their
FA profile reflects a longer term dietary intake and was
recently suggested to be used as an appropriate biomarker
to investigate correlations between FA metabolism and diseases.
Therefore, the aim of this work was to develop and
validate a simple and fast methodology for the quantification
of a broad range of FAs in RBCs using gas chromatography
with flame ionization detector, as a more common
and affordable equipment suitable for biomedical and
nutritional studies including a large number of samples. For
this purpose, different sample preparation protocols were
tested and compared, including a classic two-step method
(Folch method) with modifications and different one-step methods, in which lipid extraction and derivatization were
performed simultaneously. For the one-step methods, different
methylation periods and the inclusion of a saponification
reaction were evaluated. Differences in absolute FA
concentrations were observed among the tested methods,
in particular for some metabolically relevant FAs such as
trans elaidic acid and eicosapentaenoic acid. The one-step
method with saponification and 60 min of methylation time
was selected since it allowed the identification of a higher
number of FAs, and was further submitted to in-house validation.
The proposed methodology provides a simple, fast
and accurate tool to quantitatively analyse FAs in human
RBCs, useful for clinical and nutritional studies.This work received financial support from the
European Union (FEDER funds through COMPETE) and National
Funds (FCT, Fundação para a Ciência e Tecnologia) through project
PTDC/SAU-ENB/116929/2010 and EXPL/EMS-SIS/2215/2013.
ROR acknowledges PhD scholarship SFRH/BD/97658/2013 attributed
by FCT (Fundação para a Ciência e Tecnologia).info:eu-repo/semantics/publishedVersio
PHIBSS2: survey design and z=0.5-0.8 results Molecular gas reservoirs during the winding-down of star formation
Following the success of the Plateau de Bure high-z Blue Sequence Survey (PHIBSS), we present the PHIBSS2 legacy program, a survey of the molecular gas properties of star-forming galaxies on and around the star-formation main sequence (MS) at different redshifts using IRAM’s NOrthern Extended Millimeter Array (NOEMA). This survey significantly extends the existing sample of star-forming galaxies with CO molecular gas measurements, probing the peak epoch of star formation (z = 1 − 1.6) as well as its building-up (z = 2 − 3) and winding-down (z = 0.5 − 0.8) phases. The targets are drawn from the well-studied GOODS, COSMOS, and AEGIS cosmological deep fields and uniformly sample the MS in the stellar mass (M⋆) – star formation rate (SFR) plane with log(M⋆/M⊙) = 10 − 11.8 and SFR = 3.5 − 500 M⊙ yr−1 without morphological selection, thus providing a statistically meaningful census of star-forming galaxies at different epochs. We describe the survey strategy and sample selection before focusing on the results obtained at redshift z = 0.5 − 0.8, where we report 60 CO(2-1) detections out of 61 targets. We determine molecular gas masses between 2 × 109 and 5 × 1010 M⊙ and separately obtain disc sizes and bulge-to-total (B/T) luminosity ratios from HST I-band images. The median molecular gas-to-stellar mass ratio μgas∼ = 0.28 ± 0.04, gas fraction fgas∼ = 0.22 ± 0.02, and depletion time as well as their dependence with stellar mass and offset from the MS follow published scaling relations for a much larger sample of galaxies spanning a significantly wider range of redshifts, the cosmic evolution of the SFR being mainly driven by that of the molecular gas fraction. The galaxy-averaged molecular Kennicutt–Schmidt (KS) relation between molecular gas and SFR surface densities is strikingly linear, pointing towards similar star formation timescales within galaxies at any given epoch. In terms of morphology, the molecular gas content, the SFR, the disc stellar mass, and the disc molecular gas fraction do not seem to correlate with B/T and the stellar surface density, which suggests an ongoing supply of fresh molecular gas to compensate for the build-up of the bulge. Our measurements do not yield any significant variation of the depletion time with B/T and hence no strong evidence for morphological quenching within the scatter of the MS
Inhibiting mevalonate pathway enzymes increases stromal cell resilience to a cholesterol-dependent cytolysin
Animal health depends on the ability of immune cells to kill invading pathogens, and on the resilience of tissues to tolerate the presence of pathogens. Trueperella pyogenes causes tissue pathology in many mammals by secreting a cholesterol-dependent cytolysin, pyolysin (PLO), which targets stromal cells. Cellular cholesterol is derived from squalene, which is synthesized via the mevalonate pathway enzymes, including HMGCR, FDPS and FDFT1. The present study tested the hypothesis that inhibiting enzymes in the mevalonate pathway to reduce cellular cholesterol increases the resilience of stromal cells to PLO. We first verified that depleting cellular cholesterol with methyl-β-cyclodextrin increased the resilience of stromal cells to PLO. We then used siRNA to deplete mevalonate pathway enzyme gene expression, and used pharmaceutical inhibitors, atorvastatin, alendronate or zaragozic acid to inhibit the activity of HMGCR, FDPS and FDFT1, respectively. These approaches successfully reduced cellular cholesterol abundance, but mevalonate pathway enzymes did not affect cellular resilience equally. Inhibiting FDFT1 was most effective, with zaragozic acid reducing the impact of PLO on cell viability. The present study provides evidence that inhibiting FDFT1 increases stromal cell resilience to a cholesterol-dependent cytolysin
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