Sex ratios of the white-tailed antelope ground squirrel (Ammospermophilus leucurus), Indian Wells Valley, San Bernardino County, California

We studied the white-tailed antelope ground squirrel during spring and summer 2006 to determine young-of-the-year and adult sex ratios in the Indian Wells Valley, San Bernardino County, California. We calculated a young-of-the-year sex ratio of 1.45:1 (female to male), whereas the adult sex ratio was approximately 1:1. Our young-ofthe-year sex ratio was greater than the 1.1:1 (female to male) natal sex ratio previously reported. Differences between young-of-the-year and adult sex ratios may represent low female young-of-the-year survivorship in the Indian Wells Valley.     

Regional and seasonal diet of the Western Burrowing Owl in south central Nevada

We examined diets of Western Burrowing Owls ( Athene cunicularia hypugaea ) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats ( Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice ( Reithrodontomys megalotis ) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats ( Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.     

Variation in Lewsia kelloggii (Portulacaceae) with description of a new species endemic to Idaho

Lewisia kelloggii has been understood as a rare plant with a disjunct range in California and Idaho. Examination of herbarium specimens and analysis of isozymes in 6 Idaho and 7 California populations revealed consistent differences between plants of the 2 states. Fixed differences in alleles at 2 loci (AAT2 and PGI1) distinguished Idaho from California plants. Genetic identities based on isozymes between Idaho and California populations averaged 0.58, lower than the average for congeneric plant species. Idaho plants were smaller than most California plants, but California plants were variable. The most consistent morphological difference between Idaho and California specimens was the difference in the number of glands on the margins of bracts and sepals. Idaho plants had 0 (-5) pink glands on each margin of these organs, all on teeth near the tips. In California plants these organs had 12-25 glands on each margin, the distal ones elevated on teeth and the proximal ones sessile. We recognize the Idaho plants as a new species, L. sacajaweana , and retain the name L. kelloggii for the California populations.     

Indicators of red squirrel (Tamiasciurus hudsonicus) abundance in the whitebark pine zone

We investigated occupied squirrel middens and squirrel sightings and vocalizations as indicators of red squirrel ( Tamiasciurus hudsonicus ) abundance in high-elevation whitebark pine ( Pinus albicaulis ) zone. Data were collected 1984-1989 from line transects located on 2 study sites in the Yellowstone ecosystem. We evaluated the performance of each measure on the basis of precision and biological considerations. We concluded that, of the 3 measures, active middens were the best indicator of red squirrel abundance. We also observed that the density of active middens dropped by 48%-66% between 1987 and 1989, following a severe drought and extensive wildfires that burned one of the study sites during 1988.     

Effects of cobble embeddedness on the microdistribution of the sculpin Cottus beldingi and its stonefly prey

Laboratory experiments were undertaken to assess the effects of three levels of cobble embeddedness on the microdistribution of the sculpin Cottus beldingi and its stonefly prey, Skwala Americana . Experiments were conducted separately and together as predator and prey in temperature- and flow-controlled artificial streams. When tested either separately or together, both the predator sculpin and its stonefly prey occurred in significantly greater numbers on substrata having unembedded cobbles than substrata having half- or completely embedded cobbles. Stonefly densities were greater in substrata having unembedded cobbles even though predator densities within the more embedded cobble patches were significantly lower. These findings support the hypothesis that higher predator densities influence prey densities less than the structural habitat quality of unembedded-cobble patches.     

Gene polymorphism in Netherton and common atopic disease.

Atopic dermatitis (AD) and asthma are characterized by IgE-mediated atopic (allergic) responses to common proteins (allergens), many of which are proteinases. Loci influencing atopy have been localized to a number of chromosomal regions, including the chromosome 5q31 cytokine cluster. Netherton disease is a rare recessive skin disorder in which atopy is a universal accompaniment. The gene underlying Netherton disease (SPINK5) encodes a 15-domain serine proteinase inhibitor (LEKTI) which is expressed in epithelial and mucosal surfaces and in the thymus. We have identified six coding polymorphisms in SPINK5 (Table 1) and found that a Glu420-->Lys variant shows significant association with atopy and AD in two independent panels of families. Our results implicate a previously unrecognized pathway for the development of common allergic illnesses.     

GABAergic inhibition of neurons in the ventral tegmental area.

Stimulation of the nucleus accumbens evokes a potent inhibition in neurons of the ventral tegmental area. GABA is likely to act as a transmitter in this descending inhibitory system.     

Species-dependent stereospecific serum protein binding of the oral anticoagulant drug phenprocoumon.

13 mammalian species are classified into 3 clearcut groups with respect to the stereospecific serum protein-binding of phenprocoumon: 2 groups showing opposed stereospecific binding characteristics and a 3rd group exhibiting no stereospecific binding. Structural differences in the albumin molecule account for these stereospecific differences in serum protein-binding.