Frequency-dependent (ac) Conduction in Disordered Composites: a Percolative Study

In a recent paper [Phys. Rev. B{\bf57}, 3375 (1998)], we examined in detail the nonlinear (electrical) dc response of a random resistor cum tunneling bond network ($RRTN$, introduced by us elsewhere to explain nonlinear response of metal-insulator type mixtures). In this work which is a sequel to that paper, we consider the ac response of the $RRTN$-based correlated $RC$ ($CRC$) model. Numerical solutions of the Kirchoff's laws for the $CRC$ model give a power-law exponent (= 0.7 near $p = p_c$) of the modulus of the complex ac conductance at moderately low frequencies, in conformity with experiments on various types of disordered systems. But, at very low frequencies, it gives a simple quadratic or linear dependence on the frequency depending upon whether the system is percolating or not. We do also discuss the effective medium approximation ($EMA$) of our $CRC$ and the traditional random $RC$ network model, and discuss their comparative successes and shortcomings.Comment: Revised and reduced version with 17 LaTeX pages plus 8 JPEG figure

Water-like anomalies for core-softened models of fluids: One dimension

We use a one-dimensional (1d) core-softened potential to develop a physical picture for some of the anomalies present in liquid water. The core-softened potential mimics the effect of hydrogen bonding. The interest in the 1d system stems from the facts that closed-form results are possible and that the qualitative behavior in 1d is reproduced in the liquid phase for higher dimensions. We discuss the relation between the shape of the potential and the density anomaly, and we study the entropy anomaly resulting from the density anomaly. We find that certain forms of the two-step square well potential lead to the existence at T=0 of a low-density phase favored at low pressures and of a high-density phase favored at high pressures, and to the appearance of a point $C'$ at a positive pressure, which is the analog of the T=0 ``critical point'' in the $1d$ Ising model. The existence of point $C'$ leads to anomalous behavior of the isothermal compressibility $K_T$ and the isobaric specific heat $C_P$.Comment: 22 pages, 7 figure

Assessing Preliminary Impact of the North Carolina Community Transformation Grant Project Farmers' Market Initiatives Among Rural Residents

Objective: Using the Social Determinants of Health as the study's theoretical underpinning, the authors examined the impact of the North Carolina Community Transformation Grant Project farmers' market initiatives on changes in awareness and use of farmers' markets, and fruit and vegetable consumption. Methods: During the farmers' market season, the researchers conducted a random digit-dial telephone survey among residents in 3 rural North Carolina counties to examine changes in farmers' market awareness, shopping, and fruit and vegetable consumption. They examined change over 1 year using t tests, chi-square tests, and propensity score matching. Results: In 1 county there were increases in farmers' market shopping and fruit and vegetable consumption, and in 1 county there were decreases in farmers' market shopping and fruit and vegetable consumption. Conclusions and Implications: The impact of farmers' market initiatives may be affected by county-specific socioeconomic contexts

Biallelic Mutations in ADPRHL2, Encoding ADP-Ribosylhydrolase 3, Lead to a Degenerative Pediatric Stress-Induced Epileptic Ataxia Syndrome.

ADP-ribosylation, the addition of poly-ADP ribose (PAR) onto proteins, is a response signal to cellular challenges, such as excitotoxicity or oxidative stress. This process is catalyzed by a group of enzymes referred to as poly(ADP-ribose) polymerases (PARPs). Because the accumulation of proteins with this modification results in cell death, its negative regulation restores cellular homeostasis: a process mediated by poly-ADP ribose glycohydrolases (PARGs) and ADP-ribosylhydrolase proteins (ARHs). Using linkage analysis and exome or genome sequencing, we identified recessive inactivating mutations in ADPRHL2 in six families. Affected individuals exhibited a pediatric-onset neurodegenerative disorder with progressive brain atrophy, developmental regression, and seizures in association with periods of stress, such as infections. Loss of the Drosophila paralog Parg showed lethality in response to oxidative challenge that was rescued by human ADPRHL2, suggesting functional conservation. Pharmacological inhibition of PARP also rescued the phenotype, suggesting the possibility of postnatal treatment for this genetic condition

Age at first birth in women is genetically associated with increased risk of schizophrenia

Prof. Paunio on PGC:n jäsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Identifying links between ecosystem services and Aboriginal well-Being and livelihoods in north Australia: applying the millennium ecosystem assessment framework

The livelihoods and well-being of Aboriginal and non-Aboriginal communities in remote and rural northern Australia are dependent upon the ecosystem services provided by tropical ecosystems. The well-being of all Australian citizens is measured by the Australia Bureau of Statistics (ABS) using socio-economic indicators. In this study we investigated the importance of non-market benefits derived from ecosystem services for Aboriginal well-being. Through a case study with the Mullunburra-Yidinji people in the Wet Tropics, Queensland, we applied the Millennium Ecosystem Assessment (MA) framework to identify the links between ecosystem services and the MA's six constituents of human well-being. The study demonstrated that cultural and provisioning services were key determinants of community well-being, and these are not currently measured by the ABS. We adapt the MA framework to include the ABS indicators and explore the potential strengths and weaknesses of the approach for measuring the well-being of contemporary remote and rural Aboriginal communities

Identifying links between ecosystem services and Aboriginal well-Being and livelihoods in north Australia: applying the millennium ecosystem assessment framework

The livelihoods and well-being of Aboriginal and non-Aboriginal communities in remote and rural northern Australia are dependent upon the ecosystem services provided by tropical ecosystems. The well-being of all Australian citizens is measured by the Australia Bureau of Statistics (ABS) using socio-economic indicators. In this study we investigated the importance of non-market benefits derived from ecosystem services for Aboriginal well-being. Through a case study with the Mullunburra-Yidinji people in the Wet Tropics, Queensland, we applied the Millennium Ecosystem Assessment (MA) framework to identify the links between ecosystem services and the MA's six constituents of human well-being. The study demonstrated that cultural and provisioning services were key determinants of community well-being, and these are not currently measured by the ABS. We adapt the MA framework to include the ABS indicators and explore the potential strengths and weaknesses of the approach for measuring the well-being of contemporary remote and rural Aboriginal communities

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