3,034 research outputs found
Dynamic DNA-Methylation of Retrotransposons in Rue under Drought Stress
Ruta graveolens (rue) is plant native to the Mediterranean region and presents in traditional medicine of this region since ancient times. There is poor information about the genome of Ruta and repetitive sequences and active mobile genetic elements have not been identified yet. Since rue genome is still mostly unexplored, and proliferative capability and large size of transposons make them key contributors to genome size and evolution, we aimed to isolate and characterize transposon sequences with a view to better understanding rue genome. We have isolated novel
types of Ty1-copia like LTR reverse transcriptase from Ruta graveolens, leading to investigation of the genomic organization and phylogenetic relationships. Since the activation of transposable elements in response to environmental changes represents a form of adaptive response to biotic stress, we investigated if drought stress could influence transposon methylation and if the extent of methylation has been related to expression level. The results can have implications for rue genome understanding and their potential impact on Ruta evolution
The Endoplasmic Reticulum Glucosyltransferase Recognizes Nearly Native Glycoprotein Folding Intermediates
The UDP-Glc:glycoprotein glucosyltransferase (GT), a key player in the endoplasmic reticulum (ER) quality control of glycoprotein folding, only glucosylates glycoproteins displaying non-native conformations. To determine whether GT recognizes folding intermediates or irreparably misfolded species with nearly native structures, we generated and tested as GT substrates neoglycoprotein fragments derived from chymotrypsin inhibitor 2 (GCI2) bearing from 53 to 64 (full-length) amino acids. Fragment conformations mimicked the last stage-folding structures adopted by a glycoprotein entering the ER lumen. GT catalytic efficiency (V(max)/K(m)) remained constant from GCI2-(1-53) to GCI2-(1-58) and then steadily declined to reach a minimal value with GCI2-(1-64). The same parameter showed a direct hyperbolic relationship with solvent accessibility of the single Trp residue but only in fragments exposing hydrophobic amino acid patches. Mutations introduced (GCI2-(1-63)V63S and GCI2-(1-64)V63S) produced slight structural destabilizations but increased GT catalytic efficiency. This parameter presented an inverse exponential relationship with the free energy of unfolding of canonical and mutant fragments. Moreover, the catalytic efficiency showed a linear relationship with the fraction of unfolded species in water. It was concluded that the GT-derived quality control may be operative with nearly native conformers and that no alternative ER-retaining mechanisms are required when glycoproteins approach their proper folding.Fil: Caramelo, Julio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Castro, Olga Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Prat Gay, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Parodi, Armando José A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin
Leaf and stem anatomy in eight Hypericum species (Clusiaceae)
Foliar micromorphology, epicuticular wax morphology and anatomical featuresof leaves and stem, particularly secondary xylem, were examined with light microscopy,general and histochemical staining and scanning electron microscopy in eightHypericum species. Outer tegument tissue and type of secondary xylem are determiningcharacteristics. Secondary xylem is ring-porous in H. perforatum, H. perfoliatum, H. tetrapterum, H. triquetrifolium, H. androsaemum and H. hircinum. In H. aegypticum and H. pubescens xylem is diffuse-porous, which is considered to be a more primitive type.These characteristics may be considered an additional criterion for species identification
Allium ducissae (A. subgen. Polyprason, Amaryllidaceae) a New Species from the Central Apennines (Italy)
In this paper, Allium ducissae (the LSID for the name Allium ducissae is: 77254606-1) is described as a new species based on morphological and molecular analyses, and its taxonomic
relationships are discussed. It grows in crevices on calcareous rocks, rocky slopes and grassy ledges in the subalpine belt, within two regional protected areas in the Lazio and Abruzzo administrative regions (Central Apennines, Italy). Previously, these populations were attributed to A. strictum, a species described from Siberia, belonging to A. sect. Reticulatobulbosa. The new species is distinct from A. strictum in the morphology of vegetative and reproductive structures. Indeed, it is close to A. palentinum, an endemic species to Cantabrian Mountains (NW Spain). Both molecular and morphological data support the recognition of the Allium populations coming from the Central Apennines as a new species. Allium ducissae can be clearly distinguished from A. palentinum by longer and wider tepals, longer filaments, tooth of inner filament, flower pedicels, spathe appendage, and smaller seeds. Moreover, seed testa micro-sculptures revealed slight differences between A. ducissae and A. palentinum. Chromosome counts showed that A. ducissae is diploid with 2n = 16 chromosomes, as already known for A. palentinum. Molecular analyses support the affiliation of A. ducissae and A. palentinum to A. sect. Falcatifolia, contrary to what is known for the latter species, usually included in
A. sect. Daghestanica. Finally, the IUCN assessment for the newly described species is proposed and briefly discussed
Entropia e uniformidade são parâmetros adicionais para avaliação óssea por tomografia computadorizada em pacientes com acromegalia
Tese (Doutorado)—Universidade de Brasília, Faculdade de Ciências da Saúde, 2020.A acromegalia é considerada uma causa importante de osteoporose secundária.
No entanto, estudos sobre densidade mineral óssea (DMO) têm demonstrado resultados
conflitantes e até o momento faltam estudos que avaliem um método de imagem preciso para o
diagnóstico precoce da osteoporose nesses pacientes. O objetivo deste estudo foi avaliar se
entropia e uniformidade na tomografia computadorizada (TC) são parâmetros úteis para
otimizar a avaliação da fragilidade óssea em pacientes com acromegalia. Para isso foram
reunidos 34 pacientes e 36 controles pareados por idade, sexo e fatores de risco de
desmineralização óssea em um estudo transversal. O grupo acromegálico apresentou maior
entropia óssea média (6,87 ± 0,98 vs. 6,03 ± 1,68, p = 0,013) e menor uniformidade óssea
média (0,035 ± 0,704 vs. 0,1113 ± 0,205, p = 0,035) que o grupo controle. Analisando apenas
acromegálicos, a entropia óssea média foi maior e a uniformidade óssea foi menor em
pacientes com hipogonadismo do que em pacientes sem hipogonadismo (7,28 ± 0,36 vs. 6,74 ±
1,08, p = 0,038 e 0,008 ± 0,002 vs. 0,043 ± 0,079, p = 0,031), respectivamente. Pacientes com
acromegalia apresentaram maior DMO e Z-score no colo do fêmur que no grupo controle
(1,156 ± 0,108 vs. 0,925 ± 0,326 g \ cm2, p = 0,043 e 0,6 ± 0,6 vs. -0,05 ± 0,8, p = 0,041,
respectivamente). O estudo identificou que entropia e uniformidade são parâmetros relevantes
na avaliação da fragilidade óssea em pacientes acromegálicos.Acromegaly is considered an important cause of secondary osteoporosis. However,
studies on bone mineral density (BMD) have yielded conflicting results and there are few
studies that evaluate an accurate imaging method for early diagnosis of osteoporosis in these
patients. The objective of this study was to assess whether entropy and uniformity on computed
tomography (CT) scans are useful parameters for optimization of assessment of bone fragility in
patients with acromegaly. We included 34 patients and 36 controls matched for age, sex and
risk factors of bone demineralization in a cross-sectional study. Patients and controls underwent
CT scan of the lumbosacral spine, dual-energy X-ray absormetry (DXA) and blood tests.A
software was developed to calculate the entropy and uniformity by a region of interest (ROI) of
the trabecular bone of the first lumbar vertebra (L1). The acromegalic group presented higher
mean bone entropy (6.87 ± 0.98 vs. 6.03 ± 1.68, p=0.013) and lower mean bone uniformity
(0.035 ± 0.704 vs. 0.1133 ± 0.205, p=0.035) than control group. Analyzing only acromegalics,
mean bone entropy was higher and bone uniformity was lower in patients with hypogonadism
than patients without hypogonadism (7.28 ± 0.36 vs. 6.74 ± 1.08, p=0.038 and 0.008 ± 0.002 vs.
0.043 ± 0.079, p=0.031) respectively. Patients with acromegaly presented higher BMD and Z-
score in the femoral neck than control group (1.156 ± 0.108 vs. 0.925 ± 0.326 g\cm2
, p=0.043 and 0.6 ± 0.6 vs. -0.05 ± 0.8, p= 0.041, respectively). The study identified that entropy and
uniformity are a relevant parameters data in bone fragility assessment in acromegalic patients
A colaboração premiada e a violação dos direitos e garantias fundamentais
A presente monografia objetiva realizar análise acerca da colaboração premiada prevista na Lei
12.850/13 e a sua compatibilidade com os direitos e garantias fundamentais previstos da
Constituição Federal de 1988. Primeiramente, pretende-se analisar as origens da justiça
negocial penal, sua definição e suas principais formas de manifestação processuais. Em seguida,
será realizada uma análise sobre os contornos da colaboração premiada no Brasil, seus
antecedentes legislativos, seus requisitos de validade e as renúncias e obrigações assumidas
pelo colaborador. Por último serão feitas críticas à colaboração premiada, baseadas nas
incompatibilidades encontradas da mesma com a ordem constitucional vigente
Genetic diversity and origin of the rare, narrow endemic Asperula crassifolia (Rubiaceae)
We examined the patterns of genetic variation in the narrow endemic Asperula crassifolia (Campania, southern Italy), taking into account the schizoendemic distribution of the Mediterranean members of Asperula sect. Cynanchicae. We obtained plastid DNA sequences of the rps16 intron and the trnC-petN intergenic spacer for several members of A. sect. Cynanchicae, for three living populations (48 individuals) and ten herbarium specimens of A. crassifolia. We also analysed nSSR data for A. crassifolia, to infer population diversity and differentiation. Our results suggest that the centre of diversity of A. crassifolia is the island of Capri, where A. crassifolia harbours four different ptDNA haplotypes, two of which are shared with other species of sect. Cynanchicae. Microsatellite analyses revealed low levels of genetic diversity for the mainland population (Nerano, Sorrentine Peninsula) and the neighbouring Sirenusae islets. Diversity in A. crassifolia is mainly explained by ancestral variation and recent divergence. Rarity in A. crassifolia is a natural condition; however, we express concern for the small census population size as it might trigger further rarefaction
Performance analysis of a multijunction solar cell operating under natural conditions and various concentration rates
El desempeño de una celda fotovoltaica multiunión con 1,0 cm2 es evaluado para varias tasas de concentración. Parámetros que caracterizan la celda son extraídos de curvas características obtenidas experimentalmente con base en el modelo de un diodo. Especial atención es dedicada a resistencia serie de la celda. Resultados demuestran que el procedimiento es consistente, permitiendo obtener una visión general del comportamiento de las celdas multiunión, a pesar de grandes variaciones experimentales de temperatura y radiación. Se observa una alta resistencia serie (3,8 Ω) para baja concentración. Esta resistencia disminuye, alcanzando un valor estable para altas concentraciones (0,024 Ω). Se han medido eficiencias promedio de conversión del 35% cuando se convierte la temperatura de referencia. La resistencia serie obtenida para altas concentraciones limita el índice de concentración que corresponde a máxima eficiencia entre 243 y 278. Mayores índices de concentración y probablemente eficiencias superiores requieren mayor reducción de la resistencia serie.The performance of a CPV multijunction (MJ) cell of 1.0 cm2 was evaluated for various concentration ratios. Parameters which characterize the cell were extracted from experimental characteristic curves using the one diode model. Special attention was given to series resistance which effects can change significantly the cell performance. Results obtained show that the procedure adopted is considerably consistent, enabling to obtain a general picture of solar cell behavior in spite of large temperature and irradiance experimental variations. A large series resistance (3.8 Ω) is observed for low concentration values. This resistance decays rapidly, attaining a stable value for high concentrations (0.024 Ω). Average conversion efficiency of 35% have been measured when converted to temperatures of 47 ºC. Series resistance obtained for high concentrations limits concentration ratio corresponding to maximum efficiency to values between 243 and 278. Higher concentration ratios and probably higher efficiencies require further reduction of series resistance.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES
Taxonomy Complexity of Some Tyrrhenian Endemic Limonium Species Belonging to L. multiforme Group (Plumbaginaceae): New Insights from Molecular and Morphometric Analyses
The delimitation of Limonium taxa is highly complicated due to hybridization, polyploidy, and apomixis. Many “microspecies” were described and aggregated into groups, most of which are still poorly known from both molecular and morphological points of view. The aim of this study is to investigate four endemic species from the Tyrrhenian coast of central Italy and the Ponziane Archipelago belonging to the L. multiforme group (L. amynclaeum, L. circaei, L. pandatariae, and L. pontium) by means of molecular and morphometric analyses. Molecular data by sequencing ITS and three plastid markers and morphometric data highlight new information about the taxonomy of these taxa so as to reduce them into a single specific entity. In fact, the better taxonomic choice is to consider the populations studied as part of a single species, i.e., Limonium pontium. Three subspecies are recognized, i.e., subsp. pontium [= L. circaei = L. amynclaeum; from Circeo to Gianola localities (excluding Terracina) and from islands Ponza, Palmarola, Zannone, and Santo Stefano], subsp. pandatariae comb. et stat. nov. (from island of Ventotene), and subsp. terracinense subsp. nov. (from Terracina)
Análise experimental e simulação do comportamento de sistemas fotovoltaicos de abastecimento de água
En este trabajo analizamos el comportamiento dinámico de un sistema de abastecimiento de agua. Registros del caudal de agua consumida, del caudal bombeado y de radiación solar colectada fueron obtenidos para un sistema instalado en la región semiárida del estado de Pernambuco (ciudad de Inajá), Brasil, durante dos períodos, a lo largo de los meses de marzo-abril y del mes de julio. La potencia nominal del generador fotovoltaico es 1,1 kW y el nivel estático del pozo es 23,7m. Un sistema de almacenamiento, de 14 m3 de capacidad, permite adaptar el suministro de agua al consumo. El trabajo presenta herramientas metodológicas útiles para estudiar el desempeño del sistema: a) Curva característica del sistema de bombeo; b) Estimativa de la capacidad de bombeo; c) Balance entre consumo y oferta de agua o, su equivalente, variación de la cantidad de agua acumulada en el reservatorio y d) Determinación de parámetros relativos a la capacidad de bombeo y a la capacidad de almacenamiento, que puedem ser utilizados para predecir el comportamiento a largo plazo del sistema. Estimativas realizadas a partir dos valores registrados muestran que el sistema tiene capacidad para bombear 15% más de agua que la cantidad efectivamente bombeada durante el mes de menor radiación solar a lo largo del año (julio). El volumen del tanque de agua es 22% mayor que la demanda. A pesar de que la capacidad de bombeo durante ese mes es mayor que la demanda, y no fue observado deficit durante el periodo analisado, los resultados de una simulación a largo plazo muestran que sistemas con esas características habrán de experimentar déficit en el suministro de agua durante su funcionamiento.In this paper we analyze the dynamic behavior of a photovoltaic water supply system. Records of the consumed water flow, pumped water flow and collected solar radiation were obtained for a system installed in the semiarid region of the state of Pernambuco (city of Inajá), Brazil, during two periods, along the months of March-April and the month of July. The nominal power of the photovoltaic generator is 1,1 kW and the static level of the well is 23,7m. A storage water tank, of 14 m3 of capacity, enables to match water supply and consumption. The paper presents useful methodological tools to study the performance of the system: a) Characteristic curve of the pumping system; b) Calculation of the water pumping capacity; c) Balance between demand and water supply or, its equivalent, variation of the water volume stored in the water tank and d) Determination of parameters relative to pumping and storage capacity, which allow to predict the long term behavior of the water supply system. Estimates using the measured data show that the system can pump 15% more water than the volume effectively pumped during the month of lowest solar radiation along the year (July). The volume of the water tank is 22% larger than the demand of the same period. Although the pumping capacity during that month is larger than demand, and no water deficit have been observed, results of a simulation show that systems with those characteristics will experience, in the long term, deficit in water supply.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES
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