Vanishing wildlife corridors and options for restoration: a case study from Tanzania

Conserving wildlife corridors is increasingly important for maintaining ecological and genetic connectivity in times of unprecedented habitat fragmentation. Documenting connectivity loss, assessing root causes, and exploring restoration options are therefore priority conservation goals. A 2009 nationwide assessment in Tanzania documented 31 major remaining corridors, the majority of which were described as threatened. The corridor between the Udzungwa Mountains and the Selous Game Reserve in south-central Tanzania, a major link between western and southern wildlife communities, especially for the African elephant Loxodonta africana, provides an illuminating case study. A preliminary assessment in 2005 found that connectivity was barely persisting via two remaining routes. Here we present assessments of these two corridors conducted from 2007-2010, using a combination of dung surveys, habitat mapping and questionnaires. We found that both corridor routes have become closed over the last five years. Increased farming and livestock keeping, associated with both local immigration and population growth, were the main reasons for corridor blockage. However, continued attempts by elephants to cross by both routes suggest that connectivity can be restored. This entails a process of harmonizing differing land owners and uses towards a common goal. We provide recommendations for restoring lost connectivity and discuss the prospects for preventing further loss of corridors across the country

The genetic architecture of the human cerebral cortex

INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights

Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic

Global Warming and Economic Externalities

Despite worldwide policy efforts such as the Kyoto Protocol, the emission of greenhouse gases (GHG) remains a negative externality. Economic equilibrium paths in the presence of such an uncorrected externality are inefficient; as a consequence there is no real economic opportunity cost to correcting this externality by mitigating global warming. Mitigation investment using resources diverted from conventional investments can raise the economic well-being of both current and future generations. The economic literature on GHG emissions misleadingly focuses attention on the intergenerational equity aspects of mitigation by using a hybrid constrained optimal path as the "business-as-usual" benchmark. We calibrate a simple Keynes-Ramsey growth model to illustrate the significant potential Pareto-improvement from mitigation investment, and to explain the equilibrium concept appropriate to modeling an uncorrected negative externality

Radiological survey results for the Peek Street site properties, Schenectady, New York

The Peek Street Industrial Facility, located at 425 Peek Street, Schenectady, New York, was operated by the General Electric Company for the Atomic Energy Commission (AEC) between 1947 and 1955. A variety of operations using radioactive materials were conducted at the site, but the main activities were to design an intermediate breeder reactor and to develop a chemical process for the recovery of uranium and plutonium from spent reactor fuel. Nonradioactive beryllium metal was machined on the site for breeder reactor application. The 4.5-acre site was decommissioned and released in October 1955. A radiological survey was conducted by Oak Ridge National Laboratory in November 1989. The survey included scan and grid point measurements of direct radiation levels outdoors on the five properties and inside the factory building, and radionuclide analysis of samples collected from each property. Radionuclide concentrations were determined in outdoor surface and subsurface soil samples from each property and in dust, debris, and structural materials from inside the factory building. Auger holes were logged to assess location and extent of possible subsurface residual soil radioactivity. Radionuclide concentrations were deter-mined in both indoor and outdoor water samples and in selected samples of vegetation. The presence of fixed and transferable surface residual radioactivity was investigated inside the factory building and on discarded materials outdoors on the property. High-volume air samples as well as additional selected indoor and outdoor soil samples were analyzed to determine levels of elemental beryllium

Results of the Radiological Survey at Conviber, Inc. , 644 Garfield Street, Springdale, Pennsylvania (CVP001)

As part of the Formerly Utilized Sites Remedial Action Program (FUSRAP), the US Department of Energy (DOE) is implementing a radiological survey program to determine the radiological conditions at sites that were used by the department's predecessor agencies. During the mid-1940s, and possibly continuing until 1951, the Conviber site in Springdale, Pennsylvania, was used to machine extruded uranium in support of government efforts. In 1980 a radiological scanning survey of this site was conducted by DOE and Argonne National Laboratory (ANL) staffs. Their report noted one anomaly: elevated radiation levels over a small area inside the building where uranium had been machined. Because much of the floor was inaccessible, for surveying and because of the lack of definitive records documenting use of this site, a comprehensive radiological assessment was recommended. The radiological survey discussed in this report for the site of Conviber, Inc., Springdale, Pennsylvania, was conducted by members of the Measurement Applications and Development Group of Oak Ridge National Laboratory in June of 1989. The survey included a surface gamma scan, collection of concrete and soil samples, and measurement of direct and removable alpha and beta-gamma contamination. One indoor location with a gamma measurement of 20 {mu}R/h was found. In June of 1990 ORNL staff returned to investigate the location with elevated gamma. A hole was drilled through the concrete, gamma measurements were taken, and soil samples were obtained for analyses. In these eight indoor soil samples, concentrations of {sup 238}U ranged from 90 to 20,000 pCi/g. However, under current site use, residual uranium covered by concrete does not pose a health risk

Results of the radiological survey at the Sacandaga site Glenville, New York

The Sacandaga site, located on Sacandaga Road, Glenville, New York, was operated by the General Electric Company for the Atomic Energy Commission (AEC) between 1947 and 1951. Originally used for the study and development of radar during World War II, the facilities housed later operations involving physics studies and sodium technology development in support of breeder reactor design and other AEC programs. Though not in use since the original equipment was dismantled and removed in the early 1950s, portions of the 51-acre site are known to contain buried rubble from demolished structures used in former operations. At the request of the Office of Naval Reactors through the Office of Remedial Action and Waste Technology, a characterization of current radiological conditions over the site was performed between August and October 1989. The survey included the measurement of direct radiation levels (gamma, alpha, and beta-gamma) over all surfaces both inside and outside the building and tunnel, radionuclide analysis of systematic, biased, and auger hole soil samples, and analysis of sediments from underground structures. Gamma logging of auger holes was conducted and removable contamination levels inside the tunnel were determined. Samples of soil and structural materials from within and around an excavated concrete bunker were analyzed to determine concentrations of radionuclides and nonradioactive elemental beryllium

Results of the radiological survey at Kennedy Park, Money and Sidney Streets, Lodi, New Jersey (LJ062)

Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, Kennedy Park, Money and Sidney Streets, Lodi, New Jersey (LJ062), was conducted during 1986 and 1987. Results of the survey demonstrated radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions are typical of the type of material originating from the MCW site. 4 refs., 4 figs., 3 tabs

Results of the radiological survey at the National Community Bank, 113 Essex Street, Maywood, New Jersey (MJ021)

Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, the National Community Bank, 113 Essex Street, Maywood, New Jersey (MJ021), was conducted during 1986. Results of the survey demonstrated radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions are typical of the type of material originating from the MCW site. 5 refs., 2 figs., 3 tabs