Differential transcriptomic responses to heat stress in surface and subterranean diving beetles

Subterranean habitats are generally very stable environments, and as such evolutionary transitions of organisms from surface to subterranean lifestyles may cause considerable shifts in physiology, particularly with respect to thermal tolerance. In this study we compared responses to heat shock at the molecular level in a geographically widespread, surface-dwelling water beetle to a congeneric subterranean species restricted to a single aquifer (Dytiscidae: Hydroporinae). The obligate subterranean beetle Paroster macrosturtensis is known to have a lower thermal tolerance compared to surface lineages (CTmax 38 °C cf. 42–46 °C), but the genetic basis of this physiological diference has not been characterized. We experimentally manipulated the thermal environment of 24 individuals to demonstrate that both species can mount a heat shock response at high temperatures (35 °C), as determined by comparative transcriptomics. However, genes involved in these responses difer between species and a far greater number were diferentially expressed in the surface taxon, suggesting it can mount a more robust heat shock response; these data may underpin its higher thermal tolerance compared to subterranean relatives. In contrast, the subterranean species examined not only diferentially expressed fewer genes in response to increasing temperatures, but also in the presence of the experimental setup employed here alone. Our results suggest P. macrosturtensis may be comparatively poorly equipped to respond to both thermally induced stress and environmental disturbances more broadly. The molecular fndings presented here have conservation implications for P. macrosturtensis and contribute to a growing narrative concerning weakened thermal tolerances in obligate subterranean organisms at the molecular level.Perry G. Beasley-Hall, Terry Bertozzi, Tessa M. Bradford, Charles S. P. Foster, Karl Jones, Simon M.Tierney, William F. Humphreys, Andrew D.Austin, Steven J. B. Coope

A Study of Memetic Search with Multi-parent Combination for UBQP

We present a multi-parent hybrid genetic–tabu algorithm (denoted by GTA) for the Unconstrained Binary Quadratic Programming (UBQP) problem, by incorporating tabu search into the framework of genetic algorithm. In this paper, we propose a new multi-parent combination operator for generating offspring solutions. A pool updating strategy based on a quality-and-distance criterion is used to manage the population. Experimental comparisons with leading methods for the UBQP problem on 25 large public instances demonstrate the efficacy of our proposed algorithm in terms of both solution quality and computational efficiency

Network structure of vertebrate scavenger assemblages at the global scale: drivers and ecosystem functioning implications

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Inventory of site-derived {sup 36}Cl in the Snake River plain aquifier, Idaho National Engineering Laboratory, Idaho

Radioactive waste management practices at the U.S. Department of Energy`s Idaho National Engineering Laboratory (INEL) in Idaho have introduced {sup 36}Cl (T{sub 1/2} = 301,000 yr) into the Snake River Plain aquifer underlying the site. The {sup 36}Cl is believed to originate from neutron activation of stable {sup 35}Cl in nuclear fuels (principally) and in reactor cooling/process water. Wastewater releases of {sup 3}H at the INEL have been documented by the site operators for the period 1952 to 1988. During this time, approximately 1.2 PBq of {sup 3}H (30,000 Ci) were introduced to the subsurface through disposal wells and seepage ponds. By sampling a number of monitoring and production wells downgradient from points of introduction, {sup 3}H movement and dispersion in the groundwater have been documented by the U.S. Geological Survey. The present report uses these historical {sup 3}H release and monitoring data to choose hydrologic parameters (matrix porosity and plume penetration depth) that produce concordance between the {sup 3}H release estimates and the inventory calculated from measurements of {sup 3}H in the subsurface. These parameters are then applied to {sup 36}Cl isopleths to generate an estimated {sup 36}Cl inventory in the subsurface. Using assumptions about irradiation times, neutron fluxes, and total fuel processed, as little as 23 g of stable chloride impurity in fuel elements would be adequate to produce the amount of {sup 36}Cl estimated to be in the groundwaters underlying the site. The highest atom concentration of {sup 36}Cl measured onsite (222x10{sup 10} atoms 1{sup -1}) corresponds to an activity level of {approximately}4 pCi 1{sup -1} and represents 0.2 percent of the U.S. Environmental Protection Agency`s (EPA) drinking water standard for this radionuclide (2000 pCi 1{sup -1})

Cycling of transuranic radionuclides in the Columbia River, its Estuary, and the Northeast Pacific Ocean. Progress report, February 1981-December 1981

Progress from February, 1981 through December, 1981 in research dealing with the behavior of transuranic and other radionuclides in the Columbia River downstream from the Hanford Reservation is summarized. All of the objectives outlined in last year's renewal proposal except one were met. The analyses of all cores raised from the Columbia River between McNary Reservoir and the mouth of the river were completed. This permits the establishment of a budget for Pu and Am. Analyses of four natural matrix standard reference materials for the National Bureau of Standards were also performed

Heavy element radionuclides (Pu, Np, U) and {sup 137}Cs in soils collected from the Idaho National Engineering and Environmental Laboratory and other sites in Idaho, Montana, and Wyoming

The isotopic composition of Pu in soils on and near the Idaho National Engineering and Environmental Laboratory (INEEL) has been determined in order to apportion the sources of the Pu into those derived from stratospheric fallout, regional fallout from the Nevada Test Site (NTS), and facilities on the INEEL site. Soils collected offsite in Idaho, Montana, and Wyoming were collected to further characterize NTS fallout in the region. In addition, measurements of {sup 237}Np and {sup 137}Cs were used to further identify the source of the Pu from airborne emissions at the Idaho Chemical Processing Plant (ICPP) or fugitive releases from the Subsurface Disposal Area (SDA) in the Radioactive Waste Management Complex (RWMC). There is convincing evidence from this study that {sup 241}Am, in excess of that expected from weapons-grade Pu, constituted a part of the buried waste at the SDA that has subsequently been released to the environment. Measurements of {sup 236}U in waters from the Snake River Plain aquifer and a soil core near the ICPP suggest that this radionuclide may be a unique interrogator of airborne releases from the ICPP. Neptunium-237 and {sup 238}Pu activities in INEEL soils suggest that airborne releases of Pu from the ICPP, over its operating history, may have recently been overestimated

Parallel and convergent genomic changes underlie independent subterranean colonization across beetles

Adaptation to life in caves is often accompanied by dramatically convergent changes across distantly related taxa, epitomized by the loss or reduction of eyes and pigmentation. Nevertheless, the genomic underpinnings underlying cave-related phenotypes are largely unexplored from a macroevolutionary perspective. Here we investigate genome-wide gene evolutionary dynamics in three distantly related beetle tribes with at least six instances of independent colonization of subterranean habitats, inhabiting both aquatic and terrestrial underground systems. Our results indicate that remarkable gene repertoire changes mainly driven by gene family expansions occurred prior to underground colonization in the three tribes, suggesting that genomic exaptation may have facilitated a strict subterranean lifestyle parallelly across beetle lineages. The three tribes experienced both parallel and convergent changes in the evolutionary dynamics of their gene repertoires. These findings pave the way towards a deeper understanding of the evolution of the genomic toolkit in hypogean fauna.Pau Balart-García, Leandro Aristide, Tessa M. Bradford, Perry G. Beasley-Hall, Slavko Polak, Steven J. B. Cooper, Rosa Fernánde