Population ecology of the ribbed mussel in southeastern Louisiana

Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and promoting productivity. As such, ecosystem level changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences, making it important to better understand the population distribution and ecology of native bivalve populations. Gametogenesis, recruitment, growth, mortality, size structure and density of the ribbed mussel, Geukensia demissa, were examined across a salinity gradient in southeastern Louisiana. In summer 2012, 100-m transects were placed at interior and edge marsh plots to collect data on mussel density, and vegetation data at duplicate sites in upper (salinity ~4), central (salinity ~8) and lower (salinity ~15) Barataria Bay, LA. Caged growth and recruitment plots were established adjacent to each transect, in April, and growth, mortality and recruitment of individually marked mussels within plots were recorded in November 2012. Mussels were randomly sampled monthly from low (~ 5) and high (~25) salinity marsh sites, and histologically processed to determine the seasonal progression of gametogenesis. Mussel densities were greatest within mesohaline marsh (66.6 + 18 m-2), J. roemerianus vegetation (191.2 + 42.7 m-2) and plots experiencing 20-60% annual flooding rates (46.7 + 13.8 m-2). Mussel recruitment, growth, size and survival were significantly higher at mid and high salinity marsh edge sites as compared to all interior and low salinity sites. Peak gametogenic ripeness occurred between April and September, positively correlated with temperature, and coincidental with seasonal shifts in salinity. The observed patterns of density, growth and mortality in Barataria Bay may reflect detrital food resource availability due to local site flooding rates, vegetation community distribution along the salinity gradient, and reduced predation at higher salinity edge sites

Borehole water level response to barometric pressure as an indicator of aquifer vulnerability

The response of borehole water levels to barometric pressure changes in semiconfined aquifers can be used to determine barometric response functions from which aquifer and confining layer properties can be obtained. Following earlier work on barometric response functions and aquifer confinement, we explore the barometric response function as a tool to improve the assessment of groundwater vulnerability in semiconfined aquifers, illustrated through records from two contrasting boreholes in the semiconfined Chalk Aquifer, East Yorkshire, UK. After removal of recharge and Earth tide influences on the water level signal, barometric response functions were estimated and aquifer and confining layer properties determined through an analytical model of borehole water level response to barometric pressure. A link between the thickness and vertical diffusivity of the confining layer determined from the barometric response function, and groundwater vulnerability is proposed. The amplitude spectrum for barometric pressure and instrument resolution favor determination of the barometric response function at frequencies to which confining layer diffusivities are most sensitive. Numerical modeling indicates that while the high frequency response reflects confining layer properties in the immediate vicinity of the borehole, the low frequency response reflects vertical, high diffusivity pathways though the confining layer some hundreds of meters distant. A characteristic time scale parameter, based on vertical diffusivities and thicknesses of the saturated and unsaturated confining layer, is introduced as a measure of semiconfined aquifer vulnerability. The study demonstrates that the barometric response function has potential as a tool for quantitative aquifer vulnerability assessment in semiconfined aquifers

A Measure of the Promiscuity of Proteins and Characteristics of Residues in the Vicinity of the Catalytic Site That Regulate Promiscuity

Promiscuity, the basis for the evolution of new functions through ‘tinkering’ of residues in the vicinity of the catalytic site, is yet to be quantitatively defined. We present a computational method Promiscuity Indices Estimator (PROMISE) - based on signatures derived from the spatial and electrostatic properties of the catalytic residues, to estimate the promiscuity (PromIndex) of proteins with known active site residues and 3D structure. PromIndex reflects the number of different active site signatures that have congruent matches in close proximity of its native catalytic site, the quality of the matches and difference in the enzymatic activity. Promiscuity in proteins is observed to follow a lognormal distribution (μ = 0.28, σ = 1.1 reduced chi-square = 3.0E-5). The PROMISE predicted promiscuous functions in any protein can serve as the starting point for directed evolution experiments. PROMISE ranks carboxypeptidase A and ribonuclease A amongst the more promiscuous proteins. We have also investigated the properties of the residues in the vicinity of the catalytic site that regulates its promiscuity. Linear regression establishes a weak correlation (R2∼0.1) between certain properties of the residues (charge, polar, etc) in the neighborhood of the catalytic residues and PromIndex. A stronger relationship states that most proteins with high promiscuity have high percentages of charged and polar residues within a radius of 3 Å of the catalytic site, which is validated using one-tailed hypothesis tests (P-values∼0.05). Since it is known that these characteristics are key factors in catalysis, their relationship with the promiscuity index cross validates the methodology of PROMISE

Homelessness and Crime: Do Your Friends Matter?

This paper investigates the influence of friends on crime, using data I collected among the homeless. To estimate the causal effects of friends and of the share of criminal friends on crime, I rely on two instruments. The first is the share of rainy days during one's first year as homeless: rainfall fosters homeless's concentration in sheltered places and increases the probability of interactions. The second is the share of inmates released during one's first year as homeless, which a\ua4ects the supply of criminal friends. I find that one additional friend decreases the probability of incarceration but criminal friends increases it

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Large‐scale science education intervention research we can use

This article develops an argument that the type of intervention research most useful for improving science teaching and learning and leading to scalable interventions includes both research to develop and gather evidence of the efficacy of innovations and a different kind of research, design‐based implementation research (DBIR). DBIR in education focuses on what is required to bring interventions and knowledge about learning to all students, wherever they might engage in science learning. This research focuses on implementation, both in the development and initial testing of interventions and in the scaling up process. In contrast to traditional intervention research that focuses principally on one level of educational systems, DBIR designs and tests interventions that cross levels and settings of learning, with the aim of investigating and improving the effective implementation of interventions. The article concludes by outlining four areas of DBIR that may improve the likelihood that new standards for science education will achieve their intended purpose of establishing an effective, equitable, and coherent system of opportunities for science learning in the United States. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 281–304, 2012Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90232/1/21001_ftp.pd

What Makes Retirees Happier: A Gradual or 'Cold Turkey' Retirement?

This study explores the factors that affect an individual’s happiness while transitioning into retirement. Recent studies highlight gradual retirement as an attractive option to older workers as they approach full retirement. However, it is not clear whether phasing or cold turkey makes for a happier retirement. Using longitudinal data from the Health and Retirement Study, this study explores what shapes the change in happiness between the last wave of full employment and the first wave of full retirement. Results suggest that what really matters is not the type of transition (gradual retirement or cold turkey), but whether people perceive the transition as chosen or forced

[Telegram from Jacob and Inge Honig to Ike Kempner - August 31, 1958]

Telegram sent by Jacob and Inge Honig to Ike Kempner sending best wishes and congratulations for his granddaughter's marriage

Historische, oudheid- en letterkundige studiën

door J. Honig Jz. Jr.Erschienen: Bd. 1 -

Geschiedenis der Zaanlanden

door Jacob Honig Jsz.Erschienen: Bd. 1 -