Size and Geographical Variation in PM1, PM2.5 and PM10: Source Profiles from Soils in the Western United States

Source profiles (fractional mass abundances and uncertainties) for use in chemical mass balance (CMB) source apportionment are reported for soil dust from unpaved roads and desert lands. The objectives were to add to the library of source composition profiles available for CMB studies, and to provide data on the variation in wind-blown dust composition between particle sizes and geographical locations. Samples were resuspended and sampled through PM₁, PM_2.5 and PM₁₀ inlets onto filters, then chemically analyzed for 40 elements, seven ions and eight carbon fractions. Air quality management would benefit from technology that can distinguish soil dust from sites in different geographical locations and sites with different land uses. Five geographical clusters representing Ft Bliss, TX, Dona Ana County, NM, Ft Irwin, CA, the west desert and the Canyonlands, UT, were examined. Distinctive differences were found between sites within a cluster and these differences were comparable to the differences between cluster averages. Some sites showed small differences in chemical composition between particle sizes, but these differences were less than the differences observed between nearby geographical locations. Dust emissions from sites with uniform geology have distinctive source profiles that may be useful for CMB receptor modeling. Heterogeneous regions, defined by land management boundaries, will require extensive field sampling to develop representative composite source profiles.     

Renal efficiency underlies adaptive heterothermy of heat-stressed hypohydrated goats

Tropical Animal Health and Production - We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male...     

Extinction probabilities of Jordan indigenous cattle using population viability analysis

Estimation of expected loss of genetic diversity in a population or breed within a defined future time horizon requires initially population viability analysis (PVA). The PVA needs estimates of probability of extinction (PE). In this study, the PE of Jordan indigenous cattle breed was simulated by PVA using Vortex^® modeling program. The annual numbers of recorded cows, bulls and their progeny were used as census data. Using the census data, effective population size (N_e) was calculated and found to be almost half (N_e = 40) of what is recommended (N_e = 82) by FAO [FAO, 1995. World Watch List for Domestic Animal Diversity. 2nd Ed. Rome, Italy] to escape endangerment. Furthermore, the EP, growth rate, heterozigosity and inbreeding rate were simulated using the PVA for a past and future time horizon. The estimates of EPs were sensible and depended heavily on the time horizon, physiological parameters and catastrophic events considered. The catastrophes were exotic breed competition and drought of 25% severity each on the population living. The model concludes that, while perhaps more or less variation in simulated population dynamic compared to real population dynamic in the past, the simulation was a fairly simulation of the likely fate under assumed living conditions. Further, the future simulated model concluded that the population is currently expected to decline rapidly toward extinction within the coming 10 years considering the same assumed conditions and absence of conserving genetic program. In such situation, it is recommended that an ex-situ live conservation program can only be a successful tool to conserve this endangered breed.     

Potential of Kochia prostrata and Perennial Grasses for Rangeland Restoration in Jordan

Six varieties of forage kochia (Kochia prostrata [L.] Schrad.), two Atriplex shrubs native to North America, and four drought-tolerant perennial grass varieties were seeded and evaluated under arid rangeland conditions in Jordan. Varieties were seeded in December 2007 and evaluated in 2008 and 2009 at two sites. Conditions were dry with Qurain receiving 110 mm and 73 mm and Tal Rimah receiving 58 mm and 43 mm of annual precipitation during the winters of 2007/2008 and 2008/2009, respectively. Plants were more abundant and taller (P < 0.001) at Qurain than Tal Rimah in 2008. Forage kochia frequency was 48% and 30% in 2008 at Qurain and Tal Rimah, respectively. However, no seeded plants were observed at Tal Rimah in 2009, suggesting that 58 mm and 43 mm of annual precipitation are insufficient to allow plants to persist over multiple years. At the wetter site, forage kochia abundance in 2009 was similar (P = 0.90) to that observed in 2008 and plant height increased (P < 0.001) from 2008 (14.4 cm ± 1.1 SE) to 2009 (38.4 cm ± 1.1 SE). Sahro-select and Otavny-select were the most abundant forage kochia varieties (P < 0.05), suggesting that these experimental lines could be more adapted to the environmental conditions of Jordan than the commercially available cultivar Immigrant. Frequency of perennial grass varieties declined (P < 0.001) at Qurain from 82% ± 4 SE to 39% ± 4 SE between 2008 and 2009, respectively. Among grasses, Siberian wheatgrass had better stands than crested wheatgrass, with Russian wildrye being intermediate. Based on this study, forage kochia appears to have great potential for establishing palatable perennial shrubs in arid rangeland conditions in Jordan if annual precipitation is at least 70 mm. Arid-adapted perennial grass varieties might also be useful in rangeland restoration if annual precipitation is over 100 mm.