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Hippocampal subfield volumes correlate with memory training benefit in subjective memory impairment
No full textAlthough some older adults experiencing memory problems have been shown to benefit from cognitive training, evidence regarding who will improve from this type of intervention is lacking. Automated hippocampal volumetry might be used to foresee treatment outcomes. We hypothesized that larger hippocampal volumes are associated with greater memory performance changes following training, and that effects are selectively related to specific hippocampal subfields. 19 memory clinic outpatients with subjective memory impairment (mean age = 60.9 years) underwent MRI-scanning and then followed an eight week training scheme aimed at improving verbal memory. We assessed verbal memory before and after training, and tested whether pretraining hippocampal volumes were related to memory improvements. To delineate regional specificity, we employed a new technique enabling automated volumetry of seven hippocampal subfields -including the cornu ammonis (CA) sectors and the dentate gyrus (DG). The results showed that larger hippocampal volumes before training were related to greater verbal recall improvements. Subfield volumetry revealed specific correlations between memory improvement and pretraining volumes of the left CA2/3 and CA4/DG. Depressive symptoms further gave a unique contribution in predicting gain of the intervention, independent of hippocampal volume. The results indicated that subjects with a stronger depressive symptom load benefited more from the training. A prediction model including baseline CA2/3-volume and depressive symptoms explained 42% of the variation in recall improvement. Our results are the first to suggest that hippocampal subfield volumetry is related to intervention outcomes in older adults experiencing memory problems. Also, previous studies have tended to exclude patients with concomitant depressive symptoms and memory complaints. The present results, however, strengthen the rationale and potential for cognitive intervention in these patients
A Pendulum Target Balance for Ion Engine Thrust Measurement
No full textAbstract: A thrust measurement system, based on a Pendulum Target Balance (PTB) is being built in order to characterize the performance of the ion thrusters developed at the Brazilian National Institute for Space Research (INPE). A theoretical analysis of the system is presented, together with the results of a first prototype calibration, in good agreement with numerical simulations. A final model is being assembled and will be optimized and calibrated to be capable of thrust measurements with a resolution in the µN range. Nomenclature D = distance from center of gravity to calibration mass f = focal length F = thrust g = acceleration of gravity at sea level I = PTB moment of inertia with respect to suspension axis m = PTB mass m C = calibration mass M F = thrust moment M W = weight moment MAG = optical system magnification OVL = optical system overall length P = optical path length R = distance from center of gravity to suspension axis R' = distance from thrust axis to suspension axis w = laser beam radius w 0 = laser beam waist radius W = weight z = laser beam propagation distance λ = wavelength µ = additional mass moment of inertia with respect to suspension axis ν = oscillation frequenc
No full textAbstract -Highly repetitive DNA sequences account for more than 50% of the human genome. The L1 and Alu families harbor the most common mammalian long and short interspersed elements. An Alu element is a dimer of similar, but not identical, fragments of total size about 300 bp, and originates from the 7SL RNA gene. Each element contains a bipartite promoter for RNA polymerase III, a poly(A) tract located between the monomers, a 3'-terminal poly(A) tract, and numerous CpG islands, and is flanked by short direct repeats. Alu repeats constitute more than 10% of the human genome and are capable of retroposition. Possibly, these elements played an important part in genome evolution. Insertion of an Alu element into a functionally important genome region or other Alu -dependent alterations of gene functions cause various hereditary disorders and are probably associated with carcinogenesis. In total, 14 Alu families differing in diagnostic mutations are known. Some of these, which are present in the human genome, are polymorphic and relatively recently have been inserted into new loci. Alu copies transposed during ethnic divergence of the human population are useful markers for evolutionary genetic studies
Terrain analysis of skier-triggered avalanche starting zones
No full textABSTRACT: Terrain is one of the main factors contributing to avalanche formation and important for the assessment of avalanche risk. Terrain characteristics of small to medium human triggered avalanches have however been the subject of limited attention. This work focused on analyzing the terrain characteristics of human triggered avalanches and their starting zones. Photos and shapes of avalanches in Switzerland between 1999/2000 and 2009/2010 and a high-quality digital elevation models (ADS-DOM) were used for this study. It was possible to digitalize 142 starting zones and to analyse them at high resolution with the ADS-DOM. Geomorphometric methods were used to extract different terrain features (ridges, slope, aspect, roughness, exposure and curvature) from the DEM. Furthermore a method was developed to estimate starting zones from a complete avalanche perimeter und to divide the starting zones automatically in different districts. The majority of the avalanches were released on planar or concave slopes and the roughness of the terrain corresponded a relatively constant debris covered surface. The slope angle often decreased from the crown to the Stauchwall
Coherent Expression Chromosome Cluster Analysis Reveals Differential Regulatory Functions of Amino-Terminal and Distal Parathyroid Hormone-Related Protein Domains in Prostate Carcinoma
No full textParathyroid hormone-related protein (PTHrP) has a number of cancer-related actions. While best known for causing hypercalcemia of malignancy, it also has effects on cancer cell growth, apoptosis, and angiogenesis. Studying the actions of PTHrP in human cancer is complicated because there are three isoforms and many derived peptides. Several peptides are biologically active at known or presumed cell surface receptors; in addition, the PTHrP-derived molecules can exert effects at the cell nucleus. To address this complexity, we studied gene expression in a DU 145 prostate cancer cell line that was stably transfected with control vector, PTHrP 1-173 and PTHrP 33-173. With this model, regulatory effects of the amino-terminal portion of PTHrP would result only from transduction with the full-length molecule, while effects pertaining to distal sequences would be evident with either construct. Analysis of the expression profiles by microarrays demonstrated nonoverlapping groups of differentially expressed genes. Aminoterminal PTHrP affected groups of genes involved in apoptosis, prostaglandin and sex steroid metabolism, cell-matrix interactions, and cell differentiation, while PTHrP 33-173 caused substantial increases in MHC class I antigen expression. This work demonstrates the distinct biological actions of the amino-terminus compared to distal mid-molecule or carboxy-terminal sequences of PTHrP in prostate carcinoma cells and provides targets for further study of the malignant process
FIP1L1/RARA with breakpoint at FIP1L1 intron13: a variant translocation in acute promyelocytic leukemia
Get PDFTHE EFFECT OF THE FUNCTIONALIZING AGENT TYPE ON PROCESSABILITY, MECHANICAL AND THERMAL PROPERTIES OF POLYPROPYLENE-BASED COMPOSITES
Get PDFThe aim of this study is to monitor the influence of the addition of glass fibers (GFs) treated with polydimethylsiloxane (PDMS) and aminopropyltrimethoxysilane (APTMS) on processability and mechanical and thermal properties of polypropylene. The composites based on PP/GFs were processed on a twin screw extruder-granulator, using 20% glass fibers, relative to the polymer mixture (PP/PP-g-MA). Composite granules obtained by extrusion were used in order to determine flow indices and the values obtained demonstrate that the addition of 20% GFs does not raise serious processability problems (viscosity of the mixture does not vary very widely). Thermal stability tests under load -HDT demonstrate that the best thermal stability is that of the composite reinforced with GFs-PDMS. Mechanical tests also demonstrate that tensile strength, resistance to bending, modulus and elongation at break are superior for the composite reinforced with PP/GFs-PDMS compared with the one reinforced with GFs-APTMS. This can be attributed to the fact that there is a better compatibility between polydimethylsiloxane-treated fibers and the polypropylene matrix compared with those functionalized with aminopropyltrimethoxysilane. Moreover, glass fibers treated with polydimethylsiloxane are more stable to changes in temperature and pressure that the composite is subjected to during processing. TG-DSC results demonstrate a higher thermal stability of the composite with the addition of functionalized fibers
PEER-REVIEWED. ACCEPTED FOR PUBLICATION A Note on the Quantization Mechanism within the Cold Big Bang Cosmology A Note on the Quantization Mechanism within the Cold Big Bang Cosmology 1
No full textIn my paper To the Heisenberg Indeterminacy Relation Recalling the eqn. the δE ρ , given by the eqn. (1), seems to be exclusively valid when δṘ is infinitesimal, since this expression is a first order expansion term, where we do tacitly suppose the vanishing of high order terms. But its form will remain valid in a case of finite variation, as derived is this paper, under the same conditions presented in (1), in terms of indeterminacy, says: • There is an indeterminacy δE ρ , at a given t, hence at a given R(t) andṘ(t), related to a small inteterminacy δṘ(t). A given spherical shell within a t-sliced hypersurface of simultaneity must enclose the following indeterminacy, if the least possible infinitesimal continuous variation given by the field equations in [3], eqn. The eqn. (1) by the summation over the simultaneous fluctuations within the spherical shell (since the quantum minimal energy is a spatially localized object, and the t-sliced spherical shell, a R(t)-spherical subset of simultaneous cosmological points pertaining to a t-sliced hypersurface of simultaneity, is full of cosmological substratum), where k denotes a partition, k fundamental fluctuating pieces of the simultaneous spacelike spherical shell within a t-sliced hypersurface. This sum gives the entire fluctuation within the shell. Since these pieces are within a hypersurface of simulteneity, they have got the same cosmological instant t. Hence, they have the same R(t) and the sameṘ(t) (points within the t-sliced spherical shell cannot have different R(t), since R(t) is a one-to-one function R(t) : t → R(t), and does not depend on spacelike variables; the t-sliced spherical shell is a set of instantaneous points pertaining to a t-sliced hypersurface of simultaneity such that these points are spatially distributed over an t-instantaneous volume enclosed by a tinstantaneous spherical surface with radius R(t)), the reason why the summation index l does not take into account the common factor at the right-hand side of the eqn. (2). From eqn. (57) in [3], we rewrite the eqn. Now, we reach the total instantaneous fluctuations within the spherical shell at the cosmological instant t, a sum of spacelike localized instantaneous fundamental fluctuations within the spherical shell, giving the total instantaneous fuctuation within this shell. Being the instantaneous spherical shell full of cosmological fluid at t, at each fundamental position within the spherical shell we have got a fundamental energy fluctuation with its intrinsical and fundamental quantum [3] R 0 = 2Gh/c 3 of indeterminacy, an inherent spherically simetric indeterminacy at each position within the t-sliced spacelike shell. Hence, the total fluctuation is now quantized
