Social change, migration and pregnancy intervals

Maternity histories from residents of a Pacific Island society, Tokelau, and migrants to New Zealand, are analysed using life table techniques. Inter-cohort differentials in patterns of family formation were found in the total Tokelau-origin population. The process of accelerated timing and spacing of pregnancies was more pronounced among migrants who tended to marry later, be pregnant at marriage, have shorter inter-pregnancy intervals at lower parities and to show evidence of family limitation occurring at higher parities. These results point to the significance of changing patterns of social control on strategies of family building

Density-Dependent Regulation of Brook Trout Population Dynamics along a Core-Periphery Distribution Gradient in a Central Appalachian Watershed

Spatial population models predict strong density-dependence and relatively stable population dynamics near the core of a species\u27 distribution with increasing variance and importance of density-independent processes operating towards the population periphery. Using a 10-year data set and an information-theoretic approach, we tested a series of candidate models considering density-dependent and density-independent controls on brook trout population dynamics across a core-periphery distribution gradient within a central Appalachian watershed. We sampled seven sub-populations with study sites ranging in drainage area from 1.3–60 km2and long-term average densities ranging from 0.335–0.006 trout/m. Modeled response variables included per capita population growth rate of young-of-the-year, adult, and total brook trout. We also quantified a stock-recruitment relationship for the headwater population and coefficients of variability in mean trout density for all sub-populations over time. Density-dependent regulation was prevalent throughout the study area regardless of stream size. However, density-independent temperature models carried substantial weight and likely reflect the effect of year-to-year variability in water temperature on trout dispersal between cold tributaries and warm main stems. Estimated adult carrying capacities decreased exponentially with increasing stream size from 0.24 trout/m in headwaters to 0.005 trout/m in the main stem. Finally, temporal variance in brook trout population size was lowest in the high-density headwater population, tended to peak in mid-sized streams and declined slightly in the largest streams with the lowest densities. Our results provide support for the hypothesis that local density-dependent processes have a strong control on brook trout dynamics across the entire distribution gradient. However, the mechanisms of regulation likely shift from competition for limited food and space in headwater streams to competition for thermal refugia in larger main stems. It also is likely that source-sink dynamics and dispersal from small headwater habitats may partially influence brook trout population dynamics in the main stem

The effect of sewage on uptake of inorganic nitrogen and carbon by natural populations of marine phytoplankton

The short-term effect of sewage effluent on nitrogen and carbon productivity of natural marine phytoplankton obtained near two California outfalls has been studied. Uptake of ammonium was shown to be inhibited at much lower effluent concentrations than was carbon uptake. Since the populations studied were shown to exhibit Michaelis-Menten kinetics for ammonium uptake, a precise measurement of inhibition could be obtained. The results have immediate application since the phytoplankton populations of the area studied have been shown previously to be nitrogen limited

Think Ethanol is Environmentally Friendly? Think Again

America\u27s prairies are disappearing at the fastest rate since the 1930s\u27 Dust Bowl.https://digitalcommons.usu.edu/huntsman_news/1087/thumbnail.jp

How a Goat-Farming Immigrant Changed Everything

In the dozens of articles and obituaries written about George Mitchell, who died late last month at 94, the Texas oilman, entrepreneur and philanthropist was remembered mostly as the father of the fracking boom, whose innovations led to the shale-gas revolution.https://digitalcommons.usu.edu/huntsman_news/1140/thumbnail.jp

The Population Structure of Ten Newfoundland Outports

This is the published version. Copyright 2000 Wayne State University Press.Island populations are most informative in the study of the genetic structure of human aggregates. These populations are often of small size, thus violating the Hardy-Weinberg assumption of infinite size. Some geographically isolated island populations are further subdivided by religion, ethnicity, and socioeconomic factors, reducing their effective sizes and facilitating genetic changes due to stochastic processes. Because of extreme geographic and social isolation, fishing communities or outports of Newfoundland have been investigated for genetic micro-differentiation through the founder effect and genetic drift (Crawford et al. 1995). The purpose of this paper is to examine the population structure of 10 Newfoundland outports using the allelic frequencies derived from 12 red cell antigens. To achieve this goal, first we calculated gene frequencies using maximum-likelihood estimation procedures. Second, we used /{-matrix methods to explore population differentiation. Third, we regressed mean per-locus heterozygosity on genetic distance from the gene frequency centroid to identify the most isolated populations. On the basis of this information, the three outports of Seal Cove, Island Harbor, and Tilting were found to be genetically differentiated from the other small populations. Moreover, religious and geographic subdivisions appear to explain the observed genetic variation

Big Brother Declares War on Consumption

Doctors routinely advise patients to avoid a wide range of unhealthy behavior, such as smoking, excessive alcohol consumption, a poor diet, and lack of exercise. Beyond these salutary suggestions, however, there is also a growing paternalistic trend to prohibit activities like smoking—and through targeted taxation, governments are taking aim at food deemed unhealthy for having too much fat, preservatives, salt, or sugar. New York City Mayor Michael Bloomberg\u27s ban on large, sugary drinks was just ruled unconstitutional in a unanimous decision by the state Supreme Court\u27s Appellate Division—but this ruling isn\u27t likely to discourage hardened advocates.https://digitalcommons.usu.edu/huntsman_news/1141/thumbnail.jp

Sub-megabase resolution tiling (SMRT) array-based comparative genomic hybridization profiling reveals novel gains and losses of chromosomal regions in Hodgkin Lymphoma and Anaplastic Large Cell Lymphoma cell lines

<p>Abstract</p> <p>Background</p> <p>Hodgkin lymphoma (HL) and Anaplastic Large Cell Lymphoma (ALCL), are forms of malignant lymphoma defined by unique morphologic, immunophenotypic, genotypic, and clinical characteristics, but both overexpress CD30. We used sub-megabase resolution tiling (SMRT) array-based comparative genomic hybridization to screen HL-derived cell lines (KMH2 and L428) and ALCL cell lines (DEL and SR-786) in order to identify disease-associated gene copy number gains and losses.</p> <p>Results</p> <p>Significant copy number gains and losses were observed on several chromosomes in all four cell lines. Assessment of copy number alterations with 26,819 DNA segments identified an average of 20 genetic alterations. Of the recurrent minimally altered regions identified, 11 (55%) were within previously published regions of chromosomal alterations in HL and ALCL cell lines while 9 (45%) were novel alterations not previously reported. HL cell lines L428 and KMH2 shared gains in chromosome cytobands 2q23.1-q24.2, 7q32.2-q36.3, 9p21.3-p13.3, 12q13.13-q14.1, and losses in 13q12.13-q12.3, and 18q21.32-q23. ALCL cell lines SR-786 and DEL, showed gains in cytobands 5p15.32-p14.3, 20p12.3-q13.11, and 20q13.2-q13.32. Both pairs of HL and ALCL cell lines showed losses in 18q21.32-18q23.</p> <p>Conclusion</p> <p>This study is considered to be the first one describing HL and ALCL cell line genomes at sub-megabase resolution. This high-resolution analysis allowed us to propose novel candidate target genes that could potentially contribute to the pathogenesis of HL and ALCL. FISH was used to confirm the amplification of all three isoforms of the trypsin gene (PRSS1/PRSS2/PRSS3) in KMH2 and L428 (HL) and DEL (ALCL) cell lines. These are novel findings that have not been previously reported in the lymphoma literature, and opens up an entirely new area of research that has not been previously associated with lymphoma biology. The findings raise interesting possibilities about the role of signaling pathways triggered by membrane associated serine proteases in HL and aggressive NHL, similar to those described in epithelial tumors.</p

Method Development for Determining the Removal of Metals from the Water Column under Transformation/Dissolution Conditions for Chronic Hazard Classification

An extension of the transformation/dissolution protocol (T/DP) was developed and evaluated as a tool to measure the removal of metals from the water column for chronic aquatic hazard classification. The T/DP extension (T/DP‐E) consists of 2 parts: T/DP‐E part 1, to measure metal removal from the water column via binding of metals to a substrate and subsequent settling, and T/DP‐E part 2, to assess the potential for remobilization of metals following resuspension. The T/DP‐E methodology (672‐h [28‐d] removal period, 1‐h resuspension event, and 96‐h resettling period) was tested using Cu, Co, and Sr solutions in the presence of a substrate. The metal removal rates varied from rapid removal for Cu to slower rates of removal for Co and Sr. The resuspension event did not trigger any increase in dissolved Cu, Co, or Sr. Additional 96‐h experiments were conducted using dissolved Ni, Pb, Zn, and Ag and supported the conclusion that the T/DP‐E is sufficiently robust to distinguish removal rates between metals with a wide range of reactivities. The proposed method provides a means to quantify the rate of metal removal from the water column and evaluate remobilization potential in a standardized and reliable way. Environ Toxicol Chem 2019;38:2032–2042. © 2019 SETAC.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151361/1/etc4471.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151361/2/etc4471_am.pd