1,451 research outputs found
Central potentials for polyatomic molecules. 1 - A survey of morse potentials determined from viscosity and the second virial coefficient
Morse potential function used to approximate pair interaction potential for wide variety of hydrocarbons determined from viscosity and second virial coefficien
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Demographic, clinical, and treatment characteristics of the juvenile primary fibromyalgia syndrome cohort enrolled in the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry.
BackgroundTo describe the demographic, clinical, and treatment characteristics of youth diagnosed with juvenile primary fibromyalgia syndrome (JPFS) who are seen in pediatric rheumatology clinics.MethodsInformation on demographics, symptoms, functioning, and treatments recommended and tried were obtained on patients with JPFS as part of a multi-site patient registry (the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry). Data were summarized using descriptive statistics. In a subset of patients completing registry follow-up visits, changes in symptoms, pain, and functioning were evaluated using growth modeling.ResultsOf the 201 patients with JPFS enrolled in the registry, most were Caucasian/White (85%), non-Hispanic (83%), and female (84%). Ages ranged from 9 to 20 years (M = 15.4 + 2.2). The most common symptoms reported were widespread musculoskeletal pain (91%), fatigue (84%), disordered sleep (82%), and headaches (68%). Pain intensity was rated as moderate to severe (M = 6.3 + 2.4/10). Scores on measures of functioning indicated mild to moderate impairment, with males observed to report significantly greater impairments. For the 37% of the initial cohort having follow-up data available, indicators of function and well-being were found to either worsen over time or remain relatively unchanged.ConclusionsThe symptoms of JPFS remained persistent and disabling for many patients treated by pediatric rheumatologists. Further study appears warranted to elucidate gender differences in the impact of JPFS symptoms. Work also is needed to identify accessible and effective outpatient treatment options for JPFS that can be routinely recommended or implemented by pediatric rheumatology providers
Tardigrade small heat shock proteins can limit desiccation-induced protein aggregation
Small heat shock proteins (sHSPs) are chaperones with well-characterized roles in heat stress, but potential roles for sHSPs in desiccation tolerance have not been as thoroughly explored. We identified nine sHSPs from the tardigrade Hypsibius exemplaris, each containing a conserved alpha-crystallin domain flanked by disordered regions. Many of these sHSPs are highly expressed. Multiple tardigrade and human sHSPs could improve desiccation tolerance of E. coli, suggesting that the capacity to contribute to desicco-protection is a conserved property of some sHSPs. Purification and subsequent analysis of two tardigrade sHSPs, HSP21 and HSP24.6, revealed that these proteins can oligomerize in vitro. These proteins limited heat-induced aggregation of the model enzyme citrate synthase. Heterologous expression of HSP24.6 improved bacterial heat shock survival, and the protein significantly reduced heat-induced aggregation of soluble bacterial protein. Thus, HSP24.6 likely chaperones against protein aggregation to promote heat tolerance. Furthermore, HSP21 and HSP24.6 limited desiccation-induced aggregation and loss of function of citrate synthase. This suggests a mechanism by which tardigrade sHSPs promote desiccation tolerance, by limiting desiccation-induced protein aggregation, thereby maintaining proteostasis and supporting survival. These results suggest that sHSPs provide a mechanism of general stress resistance that can also be deployed to support survival during anhydrobiosis.Small heat shock proteins from the tardigrade Hypsibius exemplaris are shown to provide a mechanism of stress resistance that can support not just heat tolerance but desiccation tolerance as well
What is the role of context in fair group recommendations?
We investigate the role played by the context, i.e. the situation the group is currently experiencing, in the design of a system that recommends sequences of activities as a multi-objective optimization problem, where the satisfaction of the group and the available time interval are two of the functions to be optimized. In particular, we highlight that the dynamic evolution of the group can be the key contextual feature that has to be considered to produce fair suggestions
A context-based approach for partitioning big data
In recent years, the amount of available data keeps growing at fast rate, and it is therefore crucial to be able to process them in an efficient way. The level of parallelism in tools such as Hadoop or Spark is determined, among other things, by the partitioning applied to the dataset. A common method is to split the data into chunks considering the number of bytes. While this approach may work well for text-based batch processing, there are a number of cases where the dataset contains structured information, such as the time or the spatial coordinates, and one may be interested in exploiting such a structure to improve the partitioning. This could have an impact on the processing time and increase the overall resource usage efficiency. This paper explores an approach based on the notion of context, such as temporal or spatial information, for partitioning the data. We design a context-based multi-dimensional partitioning technique that divides an n 12dimensional space into splits by considering the distribution of the each contextual dimension in the dataset. We tested our approach on a dataset from a touristic scenario, and our experiments show that we are able to improve the efficiency of the resource usage
What makes spatial data big? A discussion on how to partition spatial data
The amount of available spatial data has significantly increased in the last years so that traditional analysis tools have become inappropriate to effectively manage them. Therefore, many attempts have been made in order to define extensions of existing MapReduce tools, such as Hadoop or Spark, with spatial capabilities in terms of data types and algorithms. Such extensions are mainly based on the partitioning techniques implemented for textual data where the dimension is given in terms of the number of occupied bytes. However, spatial data are characterized by other features which describe their dimension, such as the number of vertices or the MBR size of geometries, which greatly affect the performance of operations, like the spatial join, during data analysis. The result is that the use of traditional partitioning techniques prevents to completely exploit the benefit of the parallel execution provided by a MapReduce environment. This paper extensively analyses the problem considering the spatial join operation as use case, performing both a theoretical and an experimental analysis for it. Moreover, it provides a solution based on a different partitioning technique, which splits complex or extensive geometries. Finally, we validate the proposed solution by means of some experiments on synthetic and real datasets
Defective ribosomal products challenge nuclear function by impairing nuclear condensate dynamics and immobilizing ubiquitin
Nuclear protein aggregation has been linked to genome instability and disease. The main source of aggregation-prone proteins in cells is defective ribosomal products (DRiPs), which are generated by translating ribosomes in the cytoplasm. Here, we report that DRiPs rapidly diffuse into the nucleus and accumulate in nucleoli and PML bodies, two membraneless organelles formed by liquid\u2013liquid phase separation. We show that nucleoli and PML bodies act as dynamic overflow compartments that recruit protein quality control factors and store DRiPs for later clearance. Whereas nucleoli serve as constitutive overflow compartments, PML bodies are stress-inducible overflow compartments for DRiPs. If DRiPs are not properly cleared by chaperones and proteasomes due to proteostasis impairment, nucleoli undergo amyloidogenesis and PML bodies solidify. Solid PML bodies immobilize 20S proteasomes and limit the recycling of free ubiquitin. Ubiquitin depletion, in turn, compromises the formation of DNA repair compartments at fragile chromosomal sites, ultimately threatening cell survival
Transporte electrogénico en el colon de ratas privadas de sodio : bloqueo de canales epiteliales versus inhibición de la NA, K-ATPASA
La privación dietaria de sodio estimula la secreción de aldosterona. En el colon de rata, la aldosterona elevada aumenta la absorción de Na+, pero además torna electrogénico el mecanismo de absorción (normalmente electroneutro). Dicho transporte electrogénico puede suprimirse mediante el bloqueo de los canales
epiteliales de Na+ en la membrana apical o la inhibición de la Na, KATPasa
de la membrana basolateral.
La absorción electrogénica de sodio está estrechamente acoplada al metabolismo aerobio, pero se desconoce si el bloqueo de los canales de Na+ reduce el
consumo de oxÃgeno en igual medida que la inhibición de la Na, K-ATPasa. Se obtuvieron preparados de mucosa aislada del colon distal de ratas alimentadas con una dieta hiposódica por 10 dÃas. Se determinó simultáneamente la corriente
de cortocircuito y el consumo de oxÃgeno en condición basal y luego del bloqueo de canales de Na+ con amilorida (n=12) o de la Na, K-ATPasa con uabaÃna (n=12).
Ambos tratamientos redujeron la corriente de cortocircuito en igual medida (>80%), pero la reducción en el consumo de oxÃgeno fue mayor con uabaÃna que con
amilorida (p<0.03). Esto se debe probablemente a que la Na, KATPasa cumple otras funciones, además del transporte transepitelial de Na+, que son suprimidas por la
uabaÃna pero no por la amilorida.Dietary sodium deprivation stimulates aldosterone secretion. In the rat colon, high aldosterone levels increases Na+ absorption but also switches the mechanism of Na+
absorption from electroneutral to electrogenic. Such electrogenic transport may be suppressed by either epithelial Na+ channel blockade at the apical membrane or
Na, K-ATPase inhibition at the basolateral membrane. Electrogenic Na+ absorption is tightly coupled to aerobic metabolism, but it is not known whether epithelial Na+
channel blockade and Na, KATPase inhibition cause the same degree of reduction in epithelial oxygen consumption. Distal colon isolated mucosa preparations were
obtained from rats fed with a low sodium diet for 10 days. Short-circuit current and oxygen consumption were simultaneously measured in baseline condition and after either blocking epithelial Na+ channels with amiloride (n=12) or the Na, KATPase
with ouabain (n=12). Both treatments reduced short-circuit current to the same degree, but the reduction in oxygen consumption was larger with ouabain (p<0.03).
The difference may be due to the fact that Na, K-ATPase has other functions besides transepithelial Na+ transport, which are suppressed by ouabain but not by amiloride.Fil: Carra, Graciela E..
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: Galella, Flavia.
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: Widenberg, Johan.
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: Ibáñez, Jorge E..
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: SaravÃ, Fernando D..
Universidad Nacional de Cuyo. Facultad de Ciencias Médica
Development Of Innovating Na Leak Detector On Pipes
International audienceWithin the ASTRID reactor project, CEA, EDF and AREVA NP, have launched a RetD program focused on the low leak rates detection of sodium on pipes. This program is focused on the development of innovating detectors, multilayer-type and Optic Fiber, involving tests in the FUTUNa sodium loop. This loop is designed to produce very accurate sodium leak rates within a range around 1cm/min, the tests being performed at different temperature (up to 550DC) on large-diameter pipe mock-ups (D 800 mm) at ambient atmosphere. This paper presents the first series of tests carried out with various materials of the first and second layer of the detector. The results are compared and discussed as well as the observations made after removing the mock-ups. The most interesting result of the overall tests is a detection time less than 2 hours for the two types of detectors
Regeneration of Algerian
Stigma/style somatic embryogenesis is one of the efficient methods in plant regeneration of most Citrus ssp., without inducing somaclonal variations. Furthermore, somatic embryogenesis from style/stigma proved to be effective in the elimination of the main citrus virus and virus-like diseases. This technique was applied on Algerian citrus collection. Different Citrus species [Citrus sinensis (L.) Osbeck, C. limon (L.) Burm, C. reticulata Blanco, C. paradisi Macfad, C. reshni Hort. ex Tan., C. jambhiri Lush and C. maxima (Burm.) Merrill] were chosen and tested for the presence of the main virus and virus-like agents. Most of the genotypes showed to be infected, mainly by viroid agents. Closed flowers were collected and in vitro cultured on a Murashige and Skoog (MS) medium supplemented with 6- benzylaminopurine. All explants produced callus about 4 to 9 days after culture initiation, whereas embryogenesis occurred after 38 to 150 days in most of the cultured genotypes. Formed embryos were cultured in a single tube before in vivo acclimatization. After sanitary assays, regenerated plants were shown to be free from the agents detected in the mother trees.Key words: Algeria, citrus germplasm, plant regeneration, sanitation, somatic embryogenesis
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