Human gamma-chain genes are rearranged in leukaemic T cells and map to the short arm of chromosome 7

Three gene families that rearrange during the somatic development of T cells have been identified in the murine genome. Two of these gene families (alpha and beta) encode subunits of the antigen-specific T-cell receptor and are also present in the human genome. The third gene family, designated here as the gamma-chain gene family, is rearranged in murine cytolytic T cells but not in most helper T cells. Here we present evidence that the human genome also contains gamma-chain genes that undergo somatic rearrangement in leukaemia-derived T cells. Murine gamma-chain genes appear to be encoded in gene segments that are analogous to the immunoglobulin gene variable, constant and joining segments. There are two closely related constant-region gene segments in the human genome. One of the constant-region genes is deleted in all three T-cell leukaemias that we have studied. The two constant-region gamma-chain genes reside on the short arm of chromosome 7 (7p15); this region is involved in chromosomal rearrangements identified in T cells from individuals with the immunodeficiency syndrome ataxia telangiectasia and observed only rarely in routine cytogenetic analyses of normal individuals. This region is also a secondary site of beta-chain gene hybridization.     

Analysis of the formation conditions and characteristics of interphase and random vanadium precipitation in a low-carbon steel during isothermal heat treatment

The characteristics of nanosized precipitates in steels depend on the heat-treatment parameters. The effects of characteristics of vanadium precipitates formed during isothermal heat treatment on the hardness of the ferrite matrix in low-carbon vanadium-alloyed steel were investigated through analysis of transmission electron microscopy images and microhardness measurements. The results show that, during isothermal holding in the temperature range from 675 to 750℃, only interphase precipitation occurs, whereas only random precipitation occurs in the ferrite matrix during holding at 600℃. Furthermore, during isothermal heat treatment between 600 and 675℃, both random and interphase precipitates occurred in the ferrite. Nanoscale vanadium carbides with different atomic ratios of vanadium (V) and carbon (C) were the dominant precipitates in the random and interphase precipitates. The sizes of random precipitation carbides were smaller than those of interphase ones. Also, the sample isothermally heat treated at 650℃ for 900 s exhibited a higher hardness with a narrower hardness distribution.     

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.     

Distributional information on birds from egg sets collected by Henry Rogers Durkee in 1870 in southwestern Wyoming

Henry Rogers Durkee collected 74 egg sets of 27 avian species in 1870 at Gilmer, Uinta County, in southwestern Wyoming. Despite the paucity of documented breeding evidence from this region during the late 19th and early 20th centuries, his material at the Smithsonian Institution was generally overlooked and has never been critically examined. Durkee's egg sets included 5 species (Sandhill Crane, Grus candensis ; Northern Rough-winged Swallow, Stelgidoteryx serripennis ; Grasshopper Sparrow, Ammodramus savannarum ; Fox Sparrow, Passerella iliaca ; Cassin's Finch, Carpodacus cassinii ) whose breeding distribution was then poorly known, 25 to more than 70 years before nests and eggs were otherwise documented in Wyoming. Durkee also collected complete egg sets of Lark Bunting ( Calamospiza melanocorys ) over 70 years before breeding was confirmed at other peripheral locations in Wyoming. In addition, Durkee's incomplete egg sets of Grasshopper Sparrow were the 1st western subspecies ( A. s. perpallidus ); his complete egg set and nest of the Fox Sparrow collected at Gilmer constituted the 2nd locality for the species or species group ( P. i. schistacea ). Although the number of egg sets Durkee collected is modest, he made a meaningful contribution to the early history of avifaunal exploration in Wyoming.     

Stoneflies (Plecoptera) of Mount Rainier National Park, Washington

Mount Rainier National Park, with an area of 95,356 ha, is approximately one-third as large as the state of Rhode Island. The lowest point is 490 m in elevation in the southeastern corner near where the Ohanapecosh River crosses the southern boundary. Columbia Crest is the highest point at 4392 m. The entire park is a rugged landscape marked by the major topographical feature, Mount Rainier, comprising over 25,899 ha, almost one-third of the park. The park lies entirely west of the crest line of the Cascade Range. Most streams in the park originate on Mount Rainier; however, several large rivers meander through the park near its boundaries. One of the first attempts to summarize the stoneflies of Washington, including Mount Rainier National Park, was Hoppe's 1938 work that reported ca 8 species. Jewett (1959) reviewed the stoneflies of the Pacific Northwest and listed 7 species that had type localities in the park: Megaleuctra kincaidi Frison, Doddsia occidentalis (Banks), Soliperla fenderi ( Jewett), Frisonia picticeps (Hanson), Isoperla rainiera Jewett, Megarcys irregularis (Banks), and M. subtruncata (Hanson). Subsequently, Kathroperla takhoma Stark and Surdick (1987) was described from the park. Samples of adult stoneflies from 1994 to 2001 indicate the presence of at least 82 species, with 64% of these typical Pacific Northwest species, and 30 species, or 36%, widespread western North American species. Seventeen new Washington state records are listed, including a substantial range extension for Lednia tumana (Ricker). One undescribed species in the Sweltsa borealis complex was also discovered. We also present illustrations of male terminalia for Despaxia augusta (Banks) and Moselia infuscata (Claassen) to aid in the identification of these species.     

Razorback sucker movements and habitat use in the San Juan River inflow, Lake Powell, Utah, 1995-1997

Seventeen subadult, hatchery-reared razorback suckers ( Xyrauchen texanus ; ( ￣x = 456 mm total length) were implanted with sonic transmitters and tracked for 23 months in the lower 89.6 km of the San Juan River (San Juan arm of Lake Powell, Utah). Fish were released at 2 sites, and 9 made extensive up- and downstream movements ( ￣x = 47.8 km; contact was lost with 4, and 4 others presumably died or lost their transmitters). The San Juan arm is primarily inundated canyon; however, most fish contacts occurred in shallow coves and shoreline with thick stands of flooded salt cedar in the upper inflow area. Eight fish frequented the Piute Farms river/lake mixing zone, and at least 4 moved upstream into the San Juan River. Seven fish were found in 2 aggregations in spring (3 fish in Neskahi Bay in 1996 and 4 fish just downstream of Piute Farms in 1997), and these may have been associated with spawning activity. Continued presence of razorback suckers in the Piute Farms area and lower San Juan River suggests the San Juan inflow to Lake Powell could be used as an alternate stocking site for reintroduction efforts.