julilili42/papers huggingface dataset:
Peer‐assisted versus faculty staff‐led skills laboratory training: a randomised controlled trial
2009-01-20

Objectives Although peer‐assisted learning (PAL) is widely employed throughout medical education, its effectiveness for training in technical procedures in skills laboratories has been subject to little systematic investigation. We conducted a prospective, randomised trial to evaluate the hypotheses that PAL is effective in technical skills training in a skills laboratory setting, and PAL is as effective as faculty staff‐led training. Methods Volunteer Year 3 medical students were randomly assigned to one of three groups. Two of these received regular skills training from either cross‐year peer tutors or experienced faculty staff. Following training, both groups were assessed using an objective structured clinical examination (OSCE) (three stations assessing various injection techniques) which was video‐recorded. Two independent video assessors scored the OSCEs using binary checklists and global ranking forms. A third student group was assessed prior to training and served as a control group. Results A total of 89 students (mean age 23.0 ± 0.2 years; 41 male, 48 female) agreed to participate in the trial. Confounding variables including prior training as a paramedic or previous experience in performing the technical procedures did not significantly differ between the three study groups. In the OSCE, PAL (58.1 ± 1 binary points, 4.9 ± 0.1 global ranking points) and faculty‐led groups (58.3 ± 1 binary points, 4.7 ± 0.1 global ranking points) scored significantly higher than the control group (33.3 ± 1 binary points, 2.7 ± 0.1 global ranking points; all P &lt; 0.0001). There was no significant difference between the PAL and faculty‐led groups ( P = 0.92 for binary checklists, P = 0.11 for global rankings). Conclusions Peer‐assisted learning is a successful method for learning technical procedures in a skills laboratory setting and can be just as effective as the training provided by experienced faculty staff.
Primary optic nerve tumours
2009-01-20

Establishing a treatment plan in cases of optic nerve glioma is difficult and must be made on an individual basis. Although both chemotherapy and radiotherapy can stabilize and sometimes improve vision in progressive tumours, chemotherapy is the preferred modality in children younger than 9 years and in patients with neurofibromatosis 1. In functionally progressive optic nerve meningioma with useful visual function, multifractioned stereotactic conformal radiotherapy is the treatment of choice.
Palaeopedological marker horizons in northern central Europe: characteristics of Lateglacial Usselo and Finow soils
2009-01-21

Lateglacial buried soil horizons, which occur widely in sandy aeolian sequences of northern central Europe, were analysed in order to evaluate their regional pedostratigraphical and palaeoenvironmental potential. Data on stratigraphy, sedimentology, pedology, geochronology and palaeobotany from 29 palaeosol‐bearing profiles at terrestrial sites are presented. Greyish Ahb and Eb horizons occur, as well as brownish Bwb and BwAhb horizons. They are 5–30 cm thick, showing similar pedological properties except colour, and they frequently bear charcoal typically from pine. Soil classification results in Albic Arenosols (Dystric) and Brunic Arenosols (Dystric) representing palaeosols of the Usselo and Finow types, respectively. Radiocarbon dating of the palaeosols reveals a dominance of Allerød ages followed by Younger Dryas and Preboreal ages. Most luminescence ages on overlying aeolian sands date into the Allerød–Younger Dryas interval. Mapping of all Usselo and Finow soil occurrences ( n =96) in northern central Europe known so far reveals a nearly closed Finow soil province between Usselo soil areas in NW Germany and central Poland, mainly situated in NE Germany. Most Usselo soils compiled contain charcoal, indicating widespread and repeated fires. Recent claims that the Usselo soil represents an event layer from rapid aeolian sedimentation caused by an extraterrestrial impact is rejected. Instead, both Usselo and Finow soils can be assumed to be pedostratigraphical marker horizons in northern central Europe and beyond.
Coulomb-Gauge Gluon Propagator and the Gribov Formula
2009-01-21

We analyze the lattice SU(2) Yang-Mills theory in the Coulomb gauge. We show that the static gluon propagator is multiplicative renormalizable and takes the simple form D(|p[over -->]|)(-1)=sqrt[|p[over -->]|2+M4/|p[over -->]|2], proposed by Gribov through heuristic arguments many years ago. We find M=0.88(1) GeV approximately 2sqrt[sigma].
Glucocorticoid-Induced Tumor Necrosis Factor Receptor–Related Protein Ligand Subverts Immunosurveillance of Acute Myeloid Leukemia in Humans
2009-01-21

Abstract The reciprocal interaction of tumor cells with the immune system is influenced by various members of the tumor necrosis factor (TNF)/TNF receptor (TNFR) family, and recently, glucocorticoid-induced TNFR-related protein (GITR) was shown to stimulate antitumor immunity in mice. However, GITR may mediate different effects in mice and men and impairs the reactivity of human natural killer (NK) cells. Here, we studied the role of GITR and its ligand (GITRL) in human acute myeloid leukemia (AML). Surface expression of GITRL was observed on AML cells in six of seven investigated cell lines, and 34 of 60 investigated AML patients whereas healthy CD34+ cells did not express GITRL. Furthermore, soluble GITRL (sGITRL) was detectable in AML patient sera in 18 of 55 investigated cases. While the presence of GITRL was not restricted to a specific AML subtype, surface expression was significantly associated with monocytic differentiation. Signaling via GITRL into patient AML cells induced the release of TNF and interleukin-10 (IL-10), and this was blocked by the inhibition of mitogen-activated protein kinases extracellular signal-regulated kinase 1/2. Furthermore, triggering GITR by surface-expressed and sGITRL impaired NK cell cytotoxicity and IFN-γ production in cocultures with leukemia cells, and NK cell reactivity could be restored by blocking GITR and neutralization of sGITRL and IL-10. Thus, whereas a stimulatory role of the GITR-GITRL system in mouse antitumor immunity has been reported, our data show that in humans GITRL expression subverts NK cell immunosurveillance of AML. Our results provide useful information for therapeutic approaches in AML, which, like haploidentical stem cell transplantation, rely on a sufficient NK cell response. [Cancer Res 2009;69(3):1037–45]
cGMP-Dependent Protein Kinase Type I Is Implicated in the Regulation of the Timing and Quality of Sleep and Wakefulness
2009-01-21

Many effects of nitric oxide (NO) are mediated by the activation of guanylyl cyclases and subsequent production of the second messenger cyclic guanosine-3',5'-monophosphate (cGMP). cGMP activates cGMP-dependent protein kinases (PRKGs), which can therefore be considered downstream effectors of NO signaling. Since NO is thought to be involved in the regulation of both sleep and circadian rhythms, we analyzed these two processes in mice deficient for cGMP-dependent protein kinase type I (PRKG1) in the brain. Prkg1 mutant mice showed a strikingly altered distribution of sleep and wakefulness over the 24 hours of a day as well as reductions in rapid-eye-movement sleep (REMS) duration and in non-REM sleep (NREMS) consolidation, and their ability to sustain waking episodes was compromised. Furthermore, they displayed a drastic decrease in electroencephalogram (EEG) power in the delta frequency range (1-4 Hz) under baseline conditions, which could be normalized after sleep deprivation. In line with the re-distribution of sleep and wakefulness, the analysis of wheel-running and drinking activity revealed more rest bouts during the activity phase and a higher percentage of daytime activity in mutant animals. No changes were observed in internal period length and phase-shifting properties of the circadian clock while chi-squared periodogram amplitude was significantly reduced, hinting at a less robust oscillator. These results indicate that PRKG1 might be involved in the stabilization and output strength of the circadian oscillator in mice. Moreover, PRKG1 deficiency results in an aberrant pattern, and consequently a reduced quality, of sleep and wakefulness, possibly due to a decreased wake-promoting output of the circadian system impinging upon sleep.
Derivation of a Compartmental Model for Quantifying 64Cu-DOTA-RGD Kinetics in Tumor-Bearing Mice
2009-01-21

We have developed and tested a compartmental model for use with the 64Cu-DOTA-RGD PET tracer and demonstrated its potential as a tool for analysis and design of preclinical and clinical imaging studies.
Motor programming of rapid finger sequences: Inferences from movement‐related brain potentials
2009-01-21

The present study investigated the predictions of two prominent models (Klapp, 1995, 2003; Rosenbaum, Inhoff, & Gordon, 1984) of programming of response sequences with the help of behavioral data, the foreperiod Contingent Negative Variation (CNV) and the Lateralized Readiness Potential (LRP). Participants performed one-key and three-key responses with their left or right hand in a precuing task. Sequence length was manipulated across blocks and precues provided either no information, partial information about hand or start finger, or full information about the response. A sequence length effect was indicated by reaction time when the precue provided partial or full information. The LRP data suggested that the duration of motor processes increases with sequence length. Foreperiod LRP and CNV revealed that participants preprogram only the first element of the sequence and prepare multiple responses if the precue provides only partial information. We discuss the implications of current findings for the two models.
Bloch oscillations of a Bose-Einstein condensate in a subwavelength optical lattice
2009-01-21

We report on experiments studying transport properties of an atomic Bose-Einstein condensate in an optical lattice of spatial period , where is an integer, realized with the dispersion of multiphoton Raman transitions. We observe Bloch oscillations, as a clear effect of quantum transport, in the sub-wavelength scale periodicity lattice. The unusually strong localisation of atoms is evident from the measured effective mass. Future prospects of the novel lattice structures are expected in the search for new quantum phases in tailored lattice structures up to quantum computing in optical nanopotentials.
Comparative studies of the auditory periphery of deep-sea fish.
2009-01-21

Many species of deep-sea fish have special sensory adaptations to help them survive at great depths and with lack of light. While such adaptations are best known in the visual system, it is likely that there are also auditory system adaptations that enable the fish to make use of the auditory scene. However, there are few data on the auditory system of deep-sea fish. The study compared inner ear structures between several such species. Some features in the ears in the species studied were similar to structures associated with enhanced hearing ability in the ears of some shallow water hearing specialists. These findings support the hypothesis that some deep-sea fishes have evolved specializations for hearing. We also report some features in the ears of deep-sea fishes that have never been seen in the ears of other vertebrates. These include specializations in the orientation of sensory hair cells, diversity in hair cell ciliary bundle shapes, and a number of unique otolith characteristics. While it is not possible to test hearing in deep-sea fishes, the various adaptations found suggest that at least some have evolved highly specialized adaptations to enable them to use sound in the deep sea.
Why jackknifing yields good latency estimates
2009-01-22

Abstract We compared individual‐participant and jackknife‐based methods for scoring the onset latencies of event‐related potential (ERP) components using a diffusion process as a model for an ERP. We studied “ramp‐like” components in which the true ERP increases or decreases monotonically, except for noise. If the growth rates of such components vary across participants, the jackknife‐based measure can easily have only 10%–20% as much error variance as the traditional method, and this advantage is magnified with more participants. We also studied ∩‐shaped or “bump‐like” components. Jackknifing generally yielded smaller error variances with these components too, especially when the component's peak amplitude varied across participants, but less so if the component's peak latency varied. These results help illuminate the reasons for the superiority of jackknife‐based onset latency measures over traditional measures in recent simulations.
SGK1-sensitive renal tubular glucose reabsorption in diabetes
2009-01-22

The hyperglycemia of diabetes mellitus increases the filtered glucose load beyond the maximal tubular transport rate and thus leads to glucosuria. Sustained hyperglycemia, however, may gradually increase the maximal renal tubular transport rate and thereby blunt the increase of urinary glucose excretion. The mechanisms accounting for the increase of renal tubular glucose transport have remained ill-defined. A candidate is the serum- and glucocorticoid-inducible kinase SGK1. The kinase has been shown to stimulate Na + -coupled glucose transport in vitro and mediate the stimulation of electrogenic intestinal glucose transport by glucocorticoids in vivo. SGK1 expression is confined to glomerula and distal nephron in intact kidneys but may extend to the proximal tubule in diabetic nephropathy. To explore whether SGK1 modifies glucose transport in diabetic kidneys, Akita mice ( akita +/− ), which develop spontaneous diabetes, have been crossbred with gene-targeted mice lacking SGK1 on one allele ( sgk1 +/− ) to eventually generate either akita +/− / sgk1 −/− or akita +/− / sgk1 +/+ mice. Both akita +/− / sgk1 −/− and akita +/− / sgk1 +/+ mice developed profound hyperglycemia (&gt;20 mM) within ∼6 wk. Body weight and plasma glucose concentrations were not significantly different between these two genotypes. However, urinary excretion of glucose and urinary excretion of fluid, Na + , and K + , as well as plasma aldosterone concentrations, were significantly higher in akita +/− / sgk1 −/− than in akita +/− / sgk1 +/+ mice. Studies in isolated perfused proximal tubules revealed that the electrogenic glucose transport was significantly lower in akita +/− / sgk1 −/− than in akita +/− / sgk1 +/+ mice. The data provide the first evidence that SGK1 participates in the stimulation of renal tubular glucose transport in diabetic kidneys.
Common variants in the UBC9 gene encoding the SUMO‐conjugating enzyme are associated with breast tumor grade
2009-01-22

Abstract UBC9 encodes a protein that conjugates small ubiquitin‐related modifier (SUMO) to target proteins resulting in a change of their localization, activity or stability. Genetic variability may affect expression and activity of UBC9 and may have an impact on breast tumor progression. We investigated associations between UBC9 genotypes and histopathological parameters in 1,021 breast cancer cases of the GENICA collection using a single nucleotide polymorphism (SNP) tagging approach. Genotyping analyses were performed by TaqMan® allelic discrimination. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by ordinal logistic regression. Multiple imputation based on HapMap data was applied to boost the power of the study. The study revealed significant associations of three UBC9 SNPs with histological grade (rs7187167, p trend = 0.001; rs11248866, p trend = 0.009; rs8052688, p trend = 0.008). Model selection identified a recessive penetrance model for rs7187167 as the best representation of tumor grade (global p = 0.001). This model did not improve by inclusion of additional SNPs in linkage disequilibrium. Imputation of SNPs in a 300 kb region around the genotyped SNPs supported rs7187167 as a major contributor to tumor grade. Compared with common allele carriers, rare homozygotes presented less frequently with high grade tumors (G3 vs. G1: OR 0.26, 95% CI 0.11–0.62; G3 vs. G2: OR 0.45, 95% CI 0.23–0.86). In addition to tumor size, nodal status and estrogen receptor status, multivariate analyses confirmed an independent role of rs7187167 as predictor of tumor grade ( p = 0.0003). The present results underline the value of genetic variation in UBC9 for breast cancer prognosis. © 2009 UICC
Analysis on pedodiversity and spatial subset representativity—the German soil map 1:1,000,000
2009-01-22

Abstract Knowledge about spatial soil variation in terms of measured pedodiversity, as well as the spatial distribution of soils in terms of spatial subset representativity, offers the possibility to estimate the quality and variance within a soil map. Additionally, it can help to identify representative sample locations. Demonstrated at the German soil map at a scale of 1:1,000,000, this study describes a methodology to analyze the distribution of taxonomical pedodiversity using the Simpson index and a new approach to derive representative spatial subsets based on a modified χ 2 ‐test (χ m 2 ), which can be used as monitoring areas. To analyze the spatial composition of the soil map and to detect differences in the underlying mapping schemes of the German soil map 1:1,000,000, three different spatial data structures were studied: (1) the entire soil map, (2) the soil map segmented into geomorphological regions, and (3) the soil map segmented into the Federal States of Germany. Representative patches of varying sizes were statistically derived for all spatial subsets as well as the entire soil map ranging from 20 km × 20 km up to 70 km × 70 km. The results show that the measured pedodiversity is linked to both the geomorphology as well as the political borders of the Federal States. On the one hand, this reveals the uncertainty of measuring pedodiversity on the basis of soil‐class maps as the spatial representation of pedodiversity is influenced by the different mapping traditions and methods applied in the 16 Federal States of Germany. On the other hand, it allows the analysis of the aggregation schemes of different landscapes. The presented approach helps to understand large soilscapes and to compare different soil maps of different states and countries as well as to enhance the soil map with additional information. Furthermore, the representative patches can be used to select soil‐monitoring areas.
A Renaissance of Elicitors: Perception of Microbe-Associated Molecular Patterns and Danger Signals by Pattern-Recognition Receptors
2009-01-23

Microbe-associated molecular patterns (MAMPs) are molecular signatures typical of whole classes of microbes, and their recognition plays a key role in innate immunity. Endogenous elicitors are similarly recognized as damage-associated molecular patterns (DAMPs). This review focuses on the diversity of MAMPs/DAMPs and on progress to identify the corresponding pattern recognition receptors (PRRs) in plants. The two best-characterized MAMP/PRR pairs, flagellin/FLS2 and EF-Tu/EFR, are discussed in detail and put into a phylogenetic perspective. Both FLS2 and EFR are leucine-rich repeat receptor kinases (LRR-RKs). Upon treatment with flagellin, FLS2 forms a heteromeric complex with BAK1, an LRR-RK that also acts as coreceptor for the brassinolide receptor BRI1. The importance of MAMP/PRR signaling for plant immunity is highlighted by the finding that plant pathogens use effectors to inhibit PRR complexes or downstream signaling events. Current evidence indicates that MAMPs, DAMPs, and effectors are all perceived as danger signals and induce a stereotypic defense response.
The polarly localized D6 PROTEIN KINASE is required for efficient auxin transport inArabidopsis thaliana
2009-01-23

The phytohormone auxin is a major determinant of plant growth and differentiation. Directional auxin transport and auxin responses are required for proper embryogenesis, organ formation, vascular development, and tropisms. Members of several protein families, including the PIN auxin efflux facilitators, have been implicated in auxin transport; however, the regulation of auxin transport by signaling proteins remains largely unexplored. We have studied a family of four highly homologous AGC protein kinases, which we designated the D6 protein kinases (D6PKs). We found that d6pk mutants have defects in lateral root initiation, root gravitropism, and shoot differentiation in axillary shoots, and that these phenotypes correlate with a reduction in auxin transport. Interestingly, D6PK localizes to the basal(lower) membrane of Arabidopsis root cells, where it colocalizes with PIN1, PIN2 and PIN4. D6PK and PIN1 interact genetically, and D6PK phosphorylates PIN proteins in vitro and in vivo. Taken together, our data show that D6PK is required for efficient auxin transport and suggest that PIN proteins are D6PK phosphorylation targets.
Damage to White Matter Fiber Tracts in Acute Spatial Neglect
2009-01-23

Previous statistical voxelwise lesion-behavior mapping (VLBM) studies have demonstrated that spatial neglect is associated with cortical and subcortical gray matter damage. However, it has also been suggested that the disorder may result from white matter injury. Our aim was to investigate the white matter connectivity in a large sample of 140 stroke patients. We combined a VLBM approach with the histological maps of the human white matter fiber tracts provided by the Jülich probabilistic cytoarchitectonic atlas. We found that damage of right perisylvian white matter connections-the superior longitudinal fasciculus, the inferior occipitofrontal fasciculus, and the superior occipitofrontal fasciculus-is a typical finding in patients with spatial neglect. However, the analysis also revealed that the largest portion of the lesion area, namely between 89.1% and 96.6%, affected brain structures other than the perisylvian white matter fiber tracts. Predominantly, these included gray matter structures such as the superior temporal, inferior parietal, inferior frontal, and insular cortices, as well as subcortically the putamen and the caudate nucleus. Damage of gray matter structures thus appears to be a strong predictor of spatial neglect.