674 research outputs found
CBM language measures as indicators of foreign-language learning: technical adequacy of scores for secondary-school students
Education and Child Studie
Increased urine IgM excretion predicts cardiovascular events in patients with type 1 diabetes nephropathy
<p>Abstract</p> <p>Background</p> <p>Diabetic nephropathy, a major complication of diabetes, is characterized by progressive renal injury and increased cardiovascular mortality. An increased urinary albumin excretion due dysfunction of the glomerular barrier is an early sign of diabetic nephropathy. An increased urinary excretion of higher molecular weight proteins such as IgM appears with progression of glomerular injury. We aim here to study the prognostic significance of urine IgM excretion in patients with type 1 diabetes mellitus (type 1 diabetic nephropathy).</p> <p>Methods</p> <p>This is an observational study of 139 patients with type1 diabetes mellitus (79 males and 60 females) under routine care at the diabetic outpatient clinic at the Lund University Hospital. The median follow-up time was 18 years (1 to 22) years. Urine albumin and urine IgM concentration were measured at time of recruitment.</p> <p>Results</p> <p>Overall 32 (14 male and 18 female) patients died in a cardiovascular event and 20 (11 male and 9 female) patients reached end-stage renal disease. Univariate analysis indicated that patient survival and renal survival were inversely associated with urine albumin excretion (RR = 2.9 and 5.8, respectively) and urine IgM excretion (RR = 4.6 and 5.7, respectively). Stratified analysis demonstrated that in patients with different degrees of albuminuria, the cardiovascular mortality rate and the incidence of end-stage renal disease was approximately three times higher in patients with increased urine IgM excretion.</p> <p>Conclusion</p> <p>An increase in urinary IgM excretion in patients with type 1 diabetes is associated with an increased risk for cardiovascular mortality and renal failure, regardless of the degree of albuminuria.</p
Sub-kHz-level relative stabilization of an intracavity doubled continuous wave optical parametric oscillator using Pound-Drever-Hall scheme
We report the relative frequency stabilization of an intracavity frequency
doubled singly resonant optical parametric oscillator on a Fabry-Perot\'etalon.
The red/orange radiation produced by the frequency doubling of the intracavity
resonant idler is stabilized using the Pound-Drever-Hall locking technique. The
relative frequency noise of this orange light, when integrated from 1 Hz to 50
kHz, corresponds to a standard deviation of 700 Hz. The frequency noise of the
pump laser is shown experimentally to be transferred to the non resonant signal
beam
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ERT and crosswell EM imaging of CO2: Examples from a shallow injection experiment at the Carbon Management Canada CaMI FRS in Southeast Alberta, Canada
Electromagnetic (EM) geophysical techniques offer the possibility of monitoring subsurface CO2 in saline reservoirs due to the fact that CO2 has high electrical resistivity compared to the surrounding geologic materials. In this paper we first discuss the underlying physics of two different borehole-based EM monitoring techniques; electrical resistivity tomography (ERT) and crosswell EM. This discussion is followed by the description of an experiment at the Carbon Management Canada CaMI FRS test site where time-lapse single well ERT and crosswell EM data have been acquired to image CO2 injection into a shallow aquifer. Resistivity imaging results from inversion of the two data types separately and jointly will be compared and contrasted, and interpretation of the extent of the injected CO2 provided
Statistical-mechanical lattice models for protein-DNA binding in chromatin
Statistical-mechanical lattice models for protein-DNA binding are well
established as a method to describe complex ligand binding equilibriums
measured in vitro with purified DNA and protein components. Recently, a new
field of applications has opened up for this approach since it has become
possible to experimentally quantify genome-wide protein occupancies in relation
to the DNA sequence. In particular, the organization of the eukaryotic genome
by histone proteins into a nucleoprotein complex termed chromatin has been
recognized as a key parameter that controls the access of transcription factors
to the DNA sequence. New approaches have to be developed to derive statistical
mechanical lattice descriptions of chromatin-associated protein-DNA
interactions. Here, we present the theoretical framework for lattice models of
histone-DNA interactions in chromatin and investigate the (competitive) DNA
binding of other chromosomal proteins and transcription factors. The results
have a number of applications for quantitative models for the regulation of
gene expression.Comment: 19 pages, 7 figures, accepted author manuscript, to appear in J.
Phys.: Cond. Mat
Expression of Interleukin-10 by in Vitro and in Vivo Activated Hepatic Stellate Cells
Activated hepatic stellate cells (HSC) participate in matrix remodeling and deposition in liver fibrosis. The present study demonstrates that interleukin (IL)-10 is expressed by HSC upon activation in vitro or in vivo and that autocrine effects of this cytokine include inhibition of collagen production. Culture activation of HSC caused a distinct increase in IL-10 mRNA level compared with freshly isolated quiescent HSC. Treatment of cultured HSC with tumor necrosis factor-alpha, transforming growth factor-beta, or lipopolysaccharide further increased IL-10 mRNA by 2-fold and resulted in the release of IL-10 protein into the medium. HSC isolated from rats after bile duct ligation (BDL) showed prominent increases in IL-10 mRNA (x 100) and protein (x 30) levels at 7 days after BDL, but such induction disappeared in advanced liver fibrosis (19 days after BDL). IL-10 expression correlated positively with mRNA expression of interstitial collagenase and inversely with that of alpha1(I) collagen. Addition of anti-IL-10 IgG to cultured HSC caused enhanced collagen production under a basal or stimulated condition with TGF-beta, tumor necrosis factor-alpha, or lipopolysaccharide. These effects were associated with increased alpha1(I) collagen mRNA and reciprocally reduced collagenase mRNA levels. Co-transfection of HSC with an IL-10 expression vector and collagen reporter genes showed a 40% inhibition of alpha1(I) collagen promoter activity. These results demonstrate that activation of HSC causes enhanced autocrine expression of IL-10 which possesses a negative autoregulatory effect on HSC collagen production mediated at least in part by alpha1(I) collagen transcriptional inhibition and stimulation of collagenase expression. These findings, along with the demonstrated early induction of HSC IL-10 expression and its late disappearance during biliary liver fibrosis, suggest its in vivo role in matrix remodeling and a possibility that failure for HSC to sustain IL-10 expression underlies pathologic progression to liver cirrhosis
Population structure and connectivity of the mountainous star coral, Orbicella faveolata , throughout the wider Caribbean region
As coral reefs continue to decline worldwide, it becomes ever more necessary to understand the connectivity between coral populations to develop efficient management strategies facilitating survival and adaptation of coral reefs in the future. Orbicella faveolata is one of the most important reef-building corals in the Caribbean and has recently experienced severe population reductions. Here, we utilize a panel of nine microsatellite loci to evaluate the genetic structure of O. faveolata and to infer connectivity across ten sites spanning the wider Caribbean region. Populations are generally well-mixed throughout the basin (FST = 0.038), although notable patterns of substructure arise at local and regional scales. Eastern and western populations appear segregated with a genetic break around the Mona Passage in the north, as has been shown previously in other species; however, we find evidence for significant connectivity between Curaçao and Mexico, suggesting that the southern margin of this barrier is permeable to dispersal. Our results also identify a strong genetic break within the Mesoamerican Barrier Reef System associated with complex oceanographic patterns that promote larval retention in southern Belize. Additionally, the diverse genetic signature at Flower Garden Banks suggests its possible function as a downstream genetic sink. The findings reported here are relevant to the ongoing conservation efforts for this important and threatened species, and contribute to the growing understanding of large-scale coral reef connectivity throughout the wider Caribbean
Population structure and connectivity of the mountainous star coral, Orbicella faveolata , throughout the wider Caribbean region
As coral reefs continue to decline worldwide, it becomes ever more necessary to understand the connectivity between coral populations to develop efficient management strategies facilitating survival and adaptation of coral reefs in the future. Orbicella faveolata is one of the most important reef-building corals in the Caribbean and has recently experienced severe population reductions. Here, we utilize a panel of nine microsatellite loci to evaluate the genetic structure of O. faveolata and to infer connectivity across ten sites spanning the wider Caribbean region. Populations are generally well-mixed throughout the basin (FST = 0.038), although notable patterns of substructure arise at local and regional scales. Eastern and western populations appear segregated with a genetic break around the Mona Passage in the north, as has been shown previously in other species; however, we find evidence for significant connectivity between Curaçao and Mexico, suggesting that the southern margin of this barrier is permeable to dispersal. Our results also identify a strong genetic break within the Mesoamerican Barrier Reef System associated with complex oceanographic patterns that promote larval retention in southern Belize. Additionally, the diverse genetic signature at Flower Garden Banks suggests its possible function as a downstream genetic sink. The findings reported here are relevant to the ongoing conservation efforts for this important and threatened species, and contribute to the growing understanding of large-scale coral reef connectivity throughout the wider Caribbean
A solid state light-matter interface at the single photon level
Coherent and reversible mapping of quantum information between light and
matter is an important experimental challenge in quantum information science.
In particular, it is a decisive milestone for the implementation of quantum
networks and quantum repeaters. So far, quantum interfaces between light and
atoms have been demonstrated with atomic gases, and with single trapped atoms
in cavities. Here we demonstrate the coherent and reversible mapping of a light
field with less than one photon per pulse onto an ensemble of 10 millions atoms
naturally trapped in a solid. This is achieved by coherently absorbing the
light field in a suitably prepared solid state atomic medium. The state of the
light is mapped onto collective atomic excitations on an optical transition and
stored for a pre-programmed time up of to 1 mu s before being released in a
well defined spatio-temporal mode as a result of a collective interference. The
coherence of the process is verified by performing an interference experiment
with two stored weak pulses with a variable phase relation. Visibilities of
more than 95% are obtained, which demonstrates the high coherence of the
mapping process at the single photon level. In addition, we show experimentally
that our interface allows one to store and retrieve light fields in multiple
temporal modes. Our results represent the first observation of collective
enhancement at the single photon level in a solid and open the way to multimode
solid state quantum memories as a promising alternative to atomic gases.Comment: 5 pages, 5 figures, version submitted on June 27 200
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