709 research outputs found
Phase III trial of valacyclovir for the prevention of shingles after hematopoietic stem cell transplantation
Cultural evolution of killer whale calls: background, mechanisms and consequences
Cultural evolution is a powerful process shaping behavioural phenotypes of many species including our own. Killer whales are one of the species with relatively well-studied vocal culture. Pods have distinct dialects comprising a mix of unique and shared call types; calves adopt the call repertoire of their matriline through social learning. We review different aspects of killer whale acoustic communication to provide insights into the cultural transmission and gene-culture co- evolution processes that produce the extreme diversity of group and population repertoires. We argue that the cultural evolution of killer whale calls is not a random process driven by steady error accumulation alone: temporal change occurs at different speeds in different components of killer whale repertoires, and constraints in call structure and horizontal transmission often degrade the phylogenetic signal. We discuss the implications from bird song and human linguistic studies, and propose several hypotheses of killer whale dialect evolution
Statistical Determination of Bulk Flow Motions
We present here a new parameterization for the bulk motions of galaxies and
clusters (in the linear regime) that can be measured statistically from the
shape and amplitude of the two-dimensional two-point correlation function. We
further propose the one-dimensional velocity dispersion (v_p) of the bulk flow
as a complementary measure of redshift-space distortions, which is
model-independent and not dependent on the normalisation method. As a
demonstration, we have applied our new methodology to the C4 cluster catalogue
constructed from Data Release Three (DR3) of the Sloan Digital Sky Survey. We
find v_p=270^{+433}km/s (also consistent with v_p=0) for this cluster sample
(at z=0.1), which is in agreement with that predicted for a WMAP5-normalised
LCDM model (i.e., v_p(LCDM=203km/s). This measurement does not lend support to
recent claims of excessive bulk motions (\simeq1000 km/s) which appear in
conflict with LCDM, although our large statistical error cannot rule them out.
From the measured coherent evolution of v_p, we develop a technique to
re-construct the perturbed potential, as well as estimating the unbiased matter
density fluctuations and scale--independent bias.Comment: 8 pages, 5 figure
Ballistic electron motion in a random magnetic field
Using a new scheme of the derivation of the non-linear -model we
consider the electron motion in a random magnetic field (RMF) in two
dimensions. The derivation is based on writing quasiclassical equations and
representing their solutions in terms of a functional integral over
supermatrices with the constraint . Contrary to the standard scheme,
neither singling out slow modes nor saddle-point approximation are used. The
-model obtained is applicable at the length scale down to the electron
wavelength. We show that this model differs from the model with a random
potential (RP).However, after averaging over fluctuations in the Lyapunov
region the standard -model is obtained leading to the conventional
localization behavior.Comment: 10 pages, no figures, to be submitted in PRB v2: Section IV is
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Systemic outcomes of (Pyr(1))-apelin-13 infusion at mid-late pregnancy in a rat model with preeclamptic features
Preeclampsia is a syndrome with diverse clinical presentation that currently has no cure. The apelin receptor system is a pleiotropic pathway with a potential for therapeutic targeting in preeclampsia. We established the systemic outcomes of (Pyr(1))-apelin-13 administration in rats with preeclamptic features (TGA-PE, female transgenic for human angiotensinogen mated to male transgenic for human renin). (Pyr(1))-apelin-13 (2 mg/kg/day) or saline was infused in TGA-PE rats via osmotic minipumps starting at day 13 of gestation (GD). At GD20, TGA-PE rats had higher blood pressure, proteinuria, lower maternal and pup weights, lower pup number, renal injury, and a larger heart compared to a control group (pregnant Sprague-Dawley rats administered vehicle). (Pyr(1))-apelin-13 did not affect maternal or fetal weights in TGA-PE. The administration of (Pyr(1))-apelin-13 reduced blood pressure, and normalized heart rate variability and baroreflex sensitivity in TGA-PE rats compared to controls. (Pyr(1))-apelin-13 increased ejection fraction in TGA-PE rats. (Pyr(1))-apelin-13 normalized proteinuria in association with lower renal cortical collagen deposition, improved renal pathology and lower immunostaining of oxidative stress markers (4-HNE and NOX-4) in TGA-PE. This study demonstrates improved hemodynamic responses and renal injury without fetal toxicity following apelin administration suggesting a role for apelin in the regulation of maternal outcomes in preeclampsia
Toward a causal link between attachment styles and mental health during the COVID-19 pandemic
Background
Recent research has shown that insecure attachment, especially attachment anxiety, is associated with poor mental health outcomes, especially during the COVID-19 pandemic. Other research suggests that insecure attachment may be linked to nonadherence to social distancing behaviours during the pandemic.
Aims
The present study aims to examine the causal links between attachment styles (secure, anxious, avoidant), mental health outcomes (depression, anxiety, loneliness) and adherence to social distancing behaviours during the first several months of the UK lockdown (between April and August 2020).
Materials & Methods
We used a nationally representative UK sample (cross-sectional n = 1325; longitudinal n = 950). The data were analysed using state-of-the-art causal discovery and targeted learning algorithms to identify causal processes.
Results
The results showed that insecure attachment styles were causally linked to poorer mental health outcomes, mediated by loneliness. Only attachment avoidance was causally linked to nonadherence to social distancing guidelines.
Discussion
Future interventions to improve mental health outcomes should focus on mitigating feelings of loneliness. Limitations include no access to pre-pandemic data and the use of categorical attachment measure.
Conclusion
Insecure attachment is a risk factor for poorer mental health outcomes
Fractional Hamilton formalism within Caputo's derivative
In this paper we develop a fractional Hamiltonian formulation for dynamic
systems defined in terms of fractional Caputo derivatives. Expressions for
fractional canonical momenta and fractional canonical Hamiltonian are given,
and a set of fractional Hamiltonian equations are obtained. Using an example,
it is shown that the canonical fractional Hamiltonian and the fractional
Euler-Lagrange formulations lead to the same set of equations.Comment: 8 page
Superparamagnetic iron oxide nanoparticles of Sabizabulin (VERU-111) for pancreatic cancer treatment
Background: Pancreatic cancer (PanCa) is one of the leading causes of cancer-related mortality in the United States due to very limited therapeutic options. Thus, developing novel therapeutic strategies will help for the management of this disease. We recently identified VERU-111, a novel synthetic molecule which showed potent anti-cancer effect against PanCa via targeting clinically important βIII and βIV tubulin isoforms. In this study, we synthesized and characterized its novel nanoformulation (MNP-VERU) and evaluated its therapeutic effects in vitro and xenograft mouse model.
Methods: MNPs were prepared by chemical precipitation method and loaded with VERU-111 using diffusion method. This formulation was characterized for particle size, chemical composition, and drug loading efficiency, using various physico-chemical methods (TEM, FT-IR, DSC, TGA, and HPLC). The internalization of MNP-VERU was achieved after 6 hours incubation with MNP-VERU in PanCa cells. To determine therapeutic efficacy of MNP-VERU, we performed various in vitro (MTS, wound healing, boyden chamber real-time xCELLigence, and apoptosis assays) and in vivo (mouse tumor xenograft) studies using PanCa. Effect of MNP-VERU on various key oncogenic signaling pathways, and miRNAs was evaluated by Western blot, immunohistochemistry (IHC), confocal microscopy, qRT-PCR and in situ hybridization (ISH) analyses respectively.
Results: Our novel MNP-VERU formulation provided average size of 110 nm in dynamic light scattering (DLS) and exhibited -8.23 to -11.65 mV zeta potential with an outstanding loading efficiency (94%). Cellular uptake and internalization studies demonstrate that MNP-VERU escape lysosomal degradation, providing efficient endosomal release to cytosol. MNP-VERU showed remarkable anti-cancer potential in various PanCa cells (Panc-1, AsPC-1, HPAF-II, BxPC-3, MiaPaca) and more effectively repressed βIII and βIV tubulin isoforms via restoring the expression of miR-200c. MNP-VERU more effectively suppressed AsPC-1 cells derived xenograft tumors in athymic nude mice.
Conclusions: Taken together, our results suggest that MNP-VERU has more anti-cancer potential than free VERU-111 against PanCa. MNP-VERU may reduce the toxicity and improve the bioavailability of free VERU-111 and could be used for the management of PanCa and health disparity
Report on EU sustainability goals: insights from Quantitative Story Telling and the WEFE nexus. MAGIC (H2020–GA 689669) Project Deliverable 5.1
Spinless particle in rapidly fluctuating random magnetic field
We study a two-dimensional spinless particle in a disordered gaussian
magnetic field with short time fluctuations, by means of the evolution equation
for the density matrix ; in this
description the two coordinates are associated with the retarded and advanced
paths respectively. The static part of the vector potential correlator is
assumed to grow with distance with a power ; the case corresponds to
a -correlated magnetic field, and to free massless field. The
value separates two different regimes, diffusion and logarithmic growth
respectively. When the baricentric coordinate diffuses with a coefficient proportional to , where
is the relative coordinate: . As the
correlator of the magnetic field is a power of distance with positive exponent;
then the coefficient scales as .
The density matrix is a function of and ,and its width in
grows for large times proportionally to .Comment: latex2e; 2 figure
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