699 research outputs found
Flow rule, self-channelization and levees in unconfined granular flows
Unconfined granular flows along an inclined plane are investigated
experimentally. During a long transient, the flow gets confined by quasistatic
banks but still spreads laterally towards a well-defined asymptotic state
following a nontrivial process. Far enough from the banks a scaling for the
depth averaged velocity is obtained, which extends the one obtained for
homogeneous steady flows. Close to jamming it exhibits a crossover towards a
nonlocal rheology. We show that the levees, commonly observed along the sides
of the deposit upon interruption of the flow, disappear for long flow
durations. We demonstrate that the morphology of the deposit builds up during
the flow, in the form of an underlying static layer, which can be deduced from
surface velocity profiles, by imposing the same flow rule everywhere in the
flow.Comment: 4 pages, 5 figure
Remote video monitoring is another example of âdying on the machineâ for critically ill patients
A critical appraisal and clinical application of Hardin SR, Dienemann J, Rudisill P, Mills KK. Inpatient fall prevention: use of in-room webcams. J Patient Saf. 2013 Mar;9(1):29-35. doi: 10.1097/PTS.0b013e3182753e4
Towards an integrated management of water resource issues in the Dyle catchment (Scheldt basin, Belgium): the European MULINO project (MULti-sectoral, INtegrated and Operational decision support system for sustainable use of water resources at the catchment scale)
The pressure on water resources is continuously increasing in Europe. If a great deal of scientific knowledge is available in many fields, this knowledge is often treated in isolation. To support the scientific basis for integrated water management, the MULINO project, an acronym for MULti-sectoral, Integrated and Operational decision support system (DSS) for the sustainable use of water resources at the catchment scale, funded by the European Union, is currently executed. The purpose of the MULINO project is to provide a tool to improve the integrated management of water resources at the catchment scale, following the requirements of the EU Water Framework Directive (WFD, J.O.CE, 2000). The DSS developed is a computer system based on hydrological modelling, multi-disciplinary indicators and multi-criteria evaluation procedures. The underlying design of the DSS is based on the Driving Forces-Pressures-State-Impact-Responses framework for reporting on environmental issues (EEA, 1999; OECD, 1993). One case study is the 700 kmÂČ Dyle catchment situated in the centre of Belgium (50°38N 4°45E) and part of the Scheldt basin. A coupling of an integrated hydrological model (SWAT: Soil and Water Assessment Tool, Arnold et al., 1993) with land use change modelling (SFARMMOD, Audsley et al., 1979) is developed in close collaboration with local end users and stakeholders. This work will provide a useful tool to analyse water resources management alternatives and to assist local managers in complex problems such as flooding, nitrate and pesticides contamination of waters, as to identify solutions for the implementation of the WFD at the catchment scale
Characteristic Changes in Decidual Gene Expression Signature in Spontaneous Term Parturition
Background: The decidua has been implicated in the "terminal pathway" of human term parturition, which is characterized by the activation of pro-inflammatory pathways in gestational tissues. However, the transcriptomic changes in the decidua leading to terminal pathway activation have not been systematically explored. This study aimed to compare the decidual expression of developmental signaling and inflammation-related genes before and after spontaneous term labor in order to reveal their involvement in this process. Materials and Methods: Chorioamniotic membranes were obtained from normal pregnant women who delivered at term with spontaneous labor (TIL, n=14) or without labor (TNL, n=15). Decidual cells were isolated from snap-frozen chorioamniotic membranes with laser microdissection. The expression of 46 genes involved in decidual development, sex steroid and prostaglandin signaling, as well as pro- and anti-inflammatory pathways was analyzed using high-throughput quantitative real-time polymerase chain reaction (qRT-PCR). Chorioamniotic membrane sections were immunostained and then semi-quantified for five proteins, and immunoassays for three chemokines were performed on maternal plasma samples. Results: The genes with the highest expression in the decidua at term gestation included insulin-like growth factor-binding protein 1 (IGFBP1), galectin-1 (LGALS1), and progestogen-associated endometrial protein (PAEP); the expression of estrogen receptor 1 (ESR1), homeobox A11 (HOXA11), interleukin 1beta (IL1B), IL8, progesterone receptor membrane component 2 (PGRMC2), and prostaglandin E synthase (PTGES) was higher in TIL than in TNL cases; the expression of chemokine C-C motif ligand 2 (CCL2), CCL5, LGALS1, LGALS3, and PAEP was lower in TIL than in TNL cases; immunostaining confirmed qRT-PCR data for IL-8, CCL2, galectin-1, galectin-3, and PAEP; and no correlations between the decidual gene expression and the maternal plasma protein concentrations of CCL2, CCL5, and IL-8 were found. Conclusion: Our data suggests that with the initiation of parturition, the decidual expression of anti-inflammatory mediators decreases, while the expression of pro-inflammatory mediators and steroid receptors increases. This shift may affect downstream signaling pathways that can lead to parturition
Improved Resolution of Reef-Coral Endosymbiont (Symbiodinium) Species Diversity, Ecology, and Evolution through psbA Non-Coding Region Genotyping
Ribosomal DNA sequence data abounds from numerous studies on the dinoflagellate endosymbionts of corals, and yet the multi-copy nature and intragenomic variability of rRNA genes and spacers confound interpretations of symbiont diversity and ecology. Making consistent sense of extensive sequence variation in a meaningful ecological and evolutionary context would benefit from the application of additional genetic markers. Sequences of the non-coding region of the plastid psbA minicircle (psbAncr) were used to independently examine symbiont genotypic and species diversity found within and between colonies of Hawaiian reef corals in the genus Montipora. A single psbAncr haplotype was recovered in most samples through direct sequencing (âŒ80â90%) and members of the same internal transcribed spacer region 2 (ITS2) type were phylogenetically differentiated from other ITS2 types by substantial psbAncr sequence divergence. The repeated sequencing of bacterially-cloned fragments of psbAncr from samples and clonal cultures often recovered a single numerically common haplotype accompanied by rare, highly-similar, sequence variants. When sequence artifacts of cloning and intragenomic variation are factored out, these data indicate that most colonies harbored one dominant Symbiodinium genotype. The cloning and sequencing of ITS2 DNA amplified from these same samples recovered numerically abundant variants (that are diagnostic of distinct Symbiodinium lineages), but also generated a large amount of sequences comprising PCR/cloning artifacts combined with ancestral and/or rare variants that, if incorporated into phylogenetic reconstructions, confound how small sequence differences are interpreted. Finally, psbAncr sequence data from a broad sampling of Symbiodinium diversity obtained from various corals throughout the Indo-Pacific were concordant with ITS lineage membership (defined by denaturing gradient gel electrophoresis screening), yet exhibited substantially greater sequence divergence and revealed strong phylogeographic structure corresponding to major biogeographic provinces. The detailed genetic resolution provided by psbAncr data brings further clarity to the ecology, evolution, and systematics of symbiotic dinoflagellates
DNA barcoding reveals the coral âlaboratory-ratâ, Stylophora pistillata encompasses multiple identities
Stylophora pistillata is a widely used coral âlab-ratâ species with highly variable morphology and a broad biogeographic range (Red Sea to western central Pacific). Here we show, by analysing Cytochorme Oxidase I sequences, from 241 samples across this range, that this taxon in fact comprises four deeply divergent clades corresponding to the Pacific-Western Australia, Chagos-Madagascar-South Africa, Gulf of Aden-Zanzibar-Madagascar, and Red Sea-Persian/Arabian Gulf-Kenya. On the basis of the fossil record of Stylophora, these four clades diverged from one another 51.5-29.6â
Mya, i.e., long before the closure of the Tethyan connection between the tropical Indo-West Pacific and Atlantic in the early Miocene (16â24â
Mya) and should be recognised as four distinct species. These findings have implications for comparative ecological and/or physiological studies carried out using Stylophora pistillata as a model species, and highlight the fact that phenotypic plasticity, thought to be common in scleractinian corals, can mask significant genetic variation
An examination of semantic impairment in amnestic MCI and AD : What can we learn from verbal fluency?
Introduction
The Verbal Fluency Test (VF) is commonly used in neuropsychology. Some studies have demonstrated a marked impairment of semantic VF compared to phonemic VF in Alzheimerâs disease (AD). Since amnestic Mild Cognitive Impairment (aMCI) is associated with increased risk of conversion to incident AD, it is relevant to examine whether a similar impairment is observed in this population. The objective of the present empirical study is to compare VF performance of aMCI patients to those of AD and elderly controls matched one-to-one for age and education.
Method
Ninety-six participants divided into three equal groups (N = 32: AD, aMCI and Controls) were included in this study. Participants in each group were, on average, 76 years of age and had 13 years of education. A repeated measures ANOVA with the Group (AD, aMCI, NC) as between-subject factor and the Fluency condition (âPâ and âanimalsâ) as within-subject factor was performed. T-tests and simple ANOVAs were also conducted to examine the interaction.
Results
There was a significant interaction between the groups and the verbal fluency condition. In AD, significantly fewer words were produced in both conditions. In contrast, participants with aMCI demonstrated a pattern similar to controls in the phonemic condition, but generated significantly fewer words in the semantic condition.
Conclusion
These results indicate a semantic memory impairment in aMCI revealed by a simple, commonly-used neuropsychological test. Future studies are needed to investigate if semantic fluency deficits can help predict future conversion to AD
Variation in Symbiodinium ITS2 Sequence Assemblages among Coral Colonies
Endosymbiotic dinoflagellates in the genus Symbiodinium are
fundamentally important to the biology of scleractinian corals, as well as to a
variety of other marine organisms. The genus Symbiodinium is
genetically and functionally diverse and the taxonomic nature of the union
between Symbiodinium and corals is implicated as a key trait
determining the environmental tolerance of the symbiosis. Surprisingly, the
question of how Symbiodinium diversity partitions within a
species across spatial scales of meters to kilometers has received little
attention, but is important to understanding the intrinsic biological scope of a
given coral population and adaptations to the local environment. Here we address
this gap by describing the Symbiodinium ITS2 sequence
assemblages recovered from colonies of the reef building coral Montipora
capitata sampled across KÄne'ohe Bay, Hawai'i. A
total of 52 corals were sampled in a nested design of Coral Colony(Site(Region))
reflecting spatial scales of meters to kilometers. A diversity of
Symbiodinium ITS2 sequences was recovered with the majority
of variance partitioning at the level of the Coral Colony. To confirm this
result, the Symbiodinium ITS2 sequence diversity in six
M. capitata colonies were analyzed in much greater depth
with 35 to 55 clones per colony. The ITS2 sequences and quantitative composition
recovered from these colonies varied significantly, indicating that each coral
hosted a different assemblage of Symbiodinium. The diversity of
Symbiodinium ITS2 sequence assemblages retrieved from
individual colonies of M. capitata here highlights the problems
inherent in interpreting multi-copy and intra-genomically variable molecular
markers, and serves as a context for discussing the utility and biological
relevance of assigning species names based on Symbiodinium ITS2
genotyping
Intermittent applied mechanical loading induces subchondral bone thickening that may be intensified locally by contiguous articular cartilage lesions
Objectives: Changes in subchondral bone (SCB) and cross-talk with articular cartilage (AC) have been linked to osteoarthritis (OA). Using micro-computed tomography (micro-CT) this study: (1) examines changes in SCB architecture in a non-invasive loading mouse model in which focal AC lesions are induced selectively in the lateral femur, and (2) determines any modifications in the contralateral knee, linked to changes in gait, which might complicate use of this limb as an internal control. Methods: Right knee joints of CBA mice were loaded: once with 2weeks of habitual use (n=7), for 2weeks (n=8) or for 5weeks (n=5). Both left (contralateral) and right (loaded) knees were micro-CT scanned and the SCB and trabecular bone analysed. Gait analysis was also performed. Results: These analyses showed a significant increase in SCB thickness in the lateral compartments in joints loaded for 5weeks, which was most marked in the lateral femur; the contralateral non-loaded knee also showed transient SCB thickening (loaded once and repetitively). Epiphyseal trabecular bone BV/TV and trabecular thickness were also increased in the lateral compartments after 5 weeks of loading, and in all joint compartments in the contralateral knee. Gait analysis showed that applied loading only affected gait in the contralateral himd-limb in all groups of mice from the second week after the first loading episode. Conclusions: These data indicate a spatial link between SCB thickening and AC lesions following mechanical trauma, and the clear limitations associated with the use of contralateral joints as controls in such OA models, and perhaps in OA diagnosis
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