4,385 research outputs found
Apathy and Striatal Gray Matter Patterns in Schizophrenia and Huntingtonâs Disease
Apathy is a symptom of many neurodegenerative and neuropsychiatric disorders, such as Huntington\u27s disease and schizophrenia. Apathy is often conceptualized as a combination of three domains, cognitive, behavioral, and emotional, characterized by impaired goal-directed behavior. The striatum has been shown to be significantly associated with executive functions and planned motor behavior via projection to the prefrontal cortex (PFC). Due to its connection to the PFC and its involvement in the basal ganglia motor circuit, the striatum is thought to be a significant part of the circuit that controls goal-directed behavior. The purpose of this study was to investigate the relationship between apathy severity and dorsal striatal grey matter concentration across several disorders, specifically Huntington\u27s disease and schizophrenia. With access to the PREDICT-HD and FBIRN datasets, structural MRI images and clinical assessments were collected from 823 and 178 participants, respectively. We employed the use of SBM to isolate relevant basal ganglia components and used the resulting loading coefficients for a multivariate analysis. In parallel, we also conducted a univariate analysis using segmented subcortical volumetric data. We then constructed a mixed linear model to examine the relationship between apathy and any gray matter patterns in the striatum. In Huntingtonâs disease, our results indicate that apathy is significantly related to the caudate and putamen atrophy with covarying in the medial PFC. In schizophrenia, our results indicate that apathy is significantly related to the putamen with covarying regions in the gyrus rectus and orbital medial PFC. We concluded that Huntingtonâs disease and schizophrenia manifest apathy in different ways in unique structures
Implementation Of High Intensity Interval Training And Autoregulatory Progressive Resistance Exercise In A Law Enforcement Training Academy
International Journal of Exercise Science 15(4): 1246-1261, 2022. The purpose of this investigation was to assess the feasibility and efficacy of implementing autoregulatory progressive resistance exercise (APRE) and high intensity interval training (HIIT) methodologies to improve physical fitness and occupational physical ability in police cadets. Two law enforcement academy classes were stratified into a standard care academy training cohort (SC; n=32, m=27, f=5) and a high performance cohort (HP; n=31; m=27, f=4) that utilized APRE and HIIT methodologies during a 17-week academy training program. Demographic, internal loading parameters, anthropometric, fitness outcomes (i.e., 1.5-mile run, 1-repetition maximum bench press, sit-up repetitions, push-up repetitions, & 300m run) and timed completion of a occupation physical ability test (OPAT) were collected at three academy time points (entrance, mid-point and exit). Mixed factor (time vs. group) repeated measures ANOVA were used to evaluate the effects of the training intervention on performance outcomes. Significance was set at p\u3c0.05. Both groups demonstrated significant improvements in all fitness outcomes except the OPAT from entrance to exit tests (p\u3c0.05). The HP experienced greater improvements in push-up performance compared to the SC (p\u3c0.001). OPAT time decreased in both groups from entrance to midpoint, but significantly increased from baseline to exit (p\u3c.05). Despite similar inter-group fitness improvements, the HP reported lower session RPE values (p\u3c0.01), indicating fitness adaptations occurred at a lower internal load. This study demonstrated the feasibility of successfully implementing APRE and HIIT methodologies within a cadet population. Furthermore, these methodologies produced similar improvements in cadet fitness and occupational performance at a lower internal load
Shorter Still: Compressing C-C Single Bonds
How short can a C-C single bond get? The bonding in a set of molecules that are related structurally to previously synthesized or theoretically examined systems with short C-C bonds is investigated. According to calculations, a single C-C bond could be compressed to 1.313 A! To the best of our knowledge, this is the shortest single C-C bond reported to date. This shortening is a consequence of a change in the C-C-C bond angle, Ξ, to minimize strain in the cages and an effort to offset the tension in the surrounding bridges
Arsenic uptake by gypsum and calcite: Modeling and probing by neutron and x-ray scattering
Here we report on two structural studies performed on As-doped gypsum (CaSO4
2H2O) and calcite (CaCO3), using neutron (D20-ILL) and x-ray (ID11-ESRF)
diffraction data and EXAFS (BM8-ESRF). The aim of this study is to determine
whether As gets into the bulk of gypsum and calcite structures or is simply
adsorbed on the surface. Different mechanisms of substitution are used as
hypotheses. The combined Rietveld analysis of neutron and x-ray diffraction
data shows an expansion of the unit cell volume proportional to the As
concentration within the samples. DFT-based simulations confirm the increase of
the unit cell volume proportional to the amount of carbonate or sulphate groups
substituted. Interpolation of the experimental Rietveld data allows us to
distinguish As substituted within the structure from that adsorbed on the
surface of both minerals.Comment: Proceedings of the Eighth International Conference on Neutron
Scatterin
Gell-Mann and Low formula for degenerate unperturbed states
The Gell-Mann and Low switching allows to transform eigenstates of an
unperturbed Hamiltonian into eigenstates of the modified Hamiltonian . This switching can be performed when the initial eigenstate is not
degenerate, under some gap conditions with the remainder of the spectrum. We
show here how to extend this approach to the case when the ground state of the
unperturbed Hamiltonian is degenerate. More precisely, we prove that the
switching procedure can still be performed when the initial states are
eigenstates of the finite rank self-adjoint operator \cP_0 V \cP_0, where
\cP_0 is the projection onto a degenerate eigenspace of
P38 MAPK expression and activation predicts failure of response to CHOP in patients with Diffuse Large B-Cell Lymphoma
The p38 MAPK is constitutively activated in B-NHL cell lines and regulates chemoresistance. Accordingly, we hypothesized that activated p38 MAPK may be associated with the in vivo unresponsiveness to chemotherapy in B-NHL patients.Tissue microarrays generated from eighty untreated patients with Diffused Large B Cell Lymphoma (DLBCL) were examined by immunohistochemistry for the expression of p38 and phospho p38 (p-p38) MAPK. In addition, both Bcl-2 and NF-ÎșB expressions were determined. Kaplan Meier analysis was assessed.Tumor tissues expressed p38 MAPK (82 %) and p-p38 MAPK (30 %). Both p38 and p-p38 MAPK expressions correlated with the high score performance status. A significant correlation was found between the expression p-p38 and poor response to CHOP. The five year median follow-up FFS was 81 % for p38(-) and 34 % for p38(+) and for OS was 83 % for p38(-) and 47 % for p38(+). The p-p38(+) tissues expressed Bcl-2 and 90 % of p-p38(-) where Bcl-2(-). The coexpression of p-p38 and Bcl-2 correlated with pool EFS and OS. There was no correlation between the expression of p-p38 and the expression of NF-ÎșB.The findings revealed, for the first time, that a subset of patients with DLBCL and whose tumors expressed high p-p38 MAPK responded poorly to CHOP therapy and had poor EFS and OS. The expression of p38, p-p38, Bcl2 and the ABC subtype are significant risk factors both p38 and p-p38 expressions remain independent prognostic factors
Top quark tensor couplings
We compute the real and imaginary parts of the one-loop electroweak
contributions to the left and right tensorial anomalous couplings of the
vertex in the Standard Model (SM). For both tensorial couplings we find that
the real part of the electroweak SM correction is close to 10 of the leading
contribution given by the QCD gluon exchange. We also find that the electroweak
real and imaginary parts for the anomalous right coupling are almost of the
same order of magnitude. The one loop SM prediction for the real part of the
left coupling is close to the 3 discovery limit derived from
. Besides, taking into account that the predictions of
new physics interactions are also at the level of a few percents when compared
with the one loop QCD gluon exchange, these electroweak corrections should be
taken into account in order to disentangle new physics effects from the
standard ones. These anomalous tensorial couplings of the top quark will be
investigated at the LHC in the near future where sensitivity to these
contributions may be achieved.Comment: 16 pages, 2 figure
The Role of Electron Captures in Chandrasekhar Mass Models for Type Ia Supernovae
The Chandrasekhar mass model for Type Ia Supernovae (SNe Ia) has received
increasing support from recent comparisons of observations with light curve
predictions and modeling of synthetic spectra. It explains SN Ia events via
thermonuclear explosions of accreting white dwarfs in binary stellar systems,
being caused by central carbon ignition when the white dwarf approaches the
Chandrasekhar mass. As the electron gas in white dwarfs is degenerate,
characterized by high Fermi energies for the high density regions in the
center, electron capture on intermediate mass and Fe-group nuclei plays an
important role in explosive burning. Electron capture affects the central
electron fraction Y_e, which determines the composition of the ejecta from such
explosions. Up to the present, astrophysical tabulations based on shell model
matrix elements were only available for light nuclei in the sd-shell. Recently
new Shell Model Monte Carlo (SMMC) and large-scale shell model diagonalization
calculations have also been performed for pf-shell nuclei. These lead in
general to a reduction of electron capture rates in comparison with previous,
more phenomenological, approaches. Making use of these new shell model based
rates, we present the first results for the composition of Fe-group nuclei
produced in the central regions of SNe Ia and possible changes in the
constraints on model parameters like ignition densities and burning front
speeds.Comment: 26 pages, 8 figures, submitted to Ap
CBe5Eâ (E = Al, Ga, In, Tl): planar pentacoordinate carbon in heptaatomic clusters
A series of clusters with the general formula CBe5E- (E = Al, Ga, In, Tl) are theoretically shown to have a planar pentacoordinate carbon atom. The structures show a simple and rigid topological frameworkâa planar EBe4 ring surrounding a C center, with one of the ring BeâBe bonds capped in-plane by a fifth Be atom. The system is stabilized by a network of multicenter Ï bonds in which the central C atom is the acceptor, and Ï systems as well by which the C atom donates charge to the Be and E atoms that encircle it
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