Molecular Genetics of Pre-1940 Red Wolves

Conservation of the endangered red wolf (Canis rufus) has become a controversial issue because its genetic and morphological composition has been altered by hybridization with coyotes (C. latrans) and possibly gray wolves (C. lupus) making its evolutionary origins difficult to ascertain. The evolutionary hypothesis based on morphological data is that the red wolf had an Early Pleistocene origin and was the predecessor of both modern coyotes and gray wolves. After 1940 red wolves hybridized with coyotes as the species vanished from the wild. In contrast to this ancient origin-recent introgression hypothesis, molecular data are more consistent with an origin through hybridization between gray wolves and coyotes. Interspecific hybridization may have occurred repeatedly over time prior to European settlement in the southcentral United States or may have been induced recently by anthropogenic changes. We review recent molecular evidence and present new results from the analysis of mitochondrial and nuclear DNA markers in pre-1940 populations of red wolves. Our results are inconsistent with an ancient origin of the red wolf and support the hybridization model. We discuss possible hybridization scenarios and reasons for the red wolf reintroduction program to be concerned with the effects of genetic introgression from coyotes.     

Prognosis of fetuses with a cystic hygroma

This paper reports our experience with 55 fetuses identified in utero to have a cystic hygroma. The outcome of fetuses with an isolated cystic hygroma, cystic hygroma with non-immune hydrops, and cystic hygroma with multiple anomalies was evaluated. Approximately two-thirds of karyotypes were aneuploid, and a strong association of septation and aneuploidy existed. Only five cases, four of which had isolated hygromas, came to term and resulted in live births. Two of these involved small non-septated lesions which resolved in utero.     

A PROGRAM TO CALCULATE CHANNEL SCOUR AND FILL1

ABSTRACT: A computer program written in BASIC calculates net changes in stream channel cross-sections. Calculations are based on dividing the channel cross-section into discrete regions of scour and fill. Internal boundaries of these regions (along the x-axis of the cross-section) are determined by the location of vertical depth measurements taken at two distinct times. The right and left boundaries of the cross-section can be specified so that scour or fill can be calculated for any portion of the profile desired.     

Economic effects of CO2 fertilization of crops: transforming changes in yield into changes in supply

Increasing concentrations of atmospheric carbon dioxide CO₂ have a beneficial effect on crop production that would tend to offset some of the economic losses that might be generated in some areas by the climatic effects of atmospheric CO₂ and other greenhouse gases. Previous estimates of the economic benefits of CO₂ fertilization on world crop production, however, were based on the assumption that percent changes in supply are equal to percent changes in yield. This assumption is not valid, however, because it confounds changes in supply with changes in quantity supplied. This error leads to an overestimation of the real economic benefits of CO₂ fertilization by 61–166%. The effects of CO₂ fertilization on crop production, therefore, will reduce some of the potential damages caused by the climatic impacts of greenhouse gases, but by significantly less than that indicated in earlier research.     

Toxic mine drainage from Asia’s biggest copper mine at Malanjkhand,India

This paper has studied the environmental deterioration due to copper mining in Malanjkhand at Central-east India. No data is available on environmental degradation at the studied site although geological aspects are well studied. Mine drainage from the mines is definitively toxic. The site is also undergoing various stages of acid mine drainage (AMD) particularly from the heap leaching sites and the tailing area. AMD impacted water steam and sediment were also analysed. Results show substantial level of contamination of almost all segments of environment. Presence of elevated level of other heavy metal viz. Au, Ag, Pb, Cr, Cd, Fe, Cu and base metals like Na, K in AMD impacted water and sediments is due to metal leaching effect of AMD. Bio monitoring with the help of benthic macro invertebrates and metal accumulation in plants was also carried to know the impact of the toxic drainage. Results prove a very significant impact on the environmental health.     

Predicting arsenic concentration in groundwater of Bangladesh using Bayesian geostatistical model

The pattern of the spatial variation in arsenic concentration in groundwater of Bangladesh is usually needed for the planning of safe drinking water. Often a model-based prediction is required for this purpose. In this paper, we fit a Bayesian hierarchical geostatistical model by utilizing data from the project, ‘Groundwater studies of arsenic concentration in Bangladesh’ conducted by the British Geological Survey and the Department of Public Health Engineering of Bangladesh. We also develop a predictive model for arsenic concentration at different levels of well-depth using the same approach. The resulting predictive model has been cross-validated by appropriate statistical tools. Finally, we obtained reliable spatially continuous predictive maps and predictive probability maps showing the areas with high probability of arsenic concentration for different levels of well-depth. Results indicate that our model fits the data well and captures a substantial amount of spatial variation. Moreover, well-depth is found to have a significant contribution in explaining the observed variation in arsenic concentration. The predictive maps that have been produced are observed to be different for various levels of well-depths and are expected to be helpful to the policy makers in preparing proper regional planning for safe drinking water.     

Metal transport phases in rivers around Jameshedpur†

Transport phases of four metals of geochemical and water quality importance were investigated in rivers around Jamshedpur. The metals iron, manganese, zinc and copper were partitioned into dissolved, adsorbed and or ion exchangeable, solid organic, oxide coating and crystalline phases applying filtration for the dissolved phase and a chemical fractionation scheme for the particulates. Iron and copper were transported mainly in the particulate phases at all sites, while manganese and zinc were found in the dissolved phase up to a hundred percent depending on the pH of water sample and pollution at the site concerned. Except copper more than 75 percent of all other three metals occurred in transport modes thought to be available to aqueous and biotic interactions. Copper was in available phases from 50 to 70 percent. The significance of metal partitioning as a factor in controlling metal availability and toxicity to biota is discussed.