Productivity, food habits, and associated variables of Barn Owls utilizing nest boxes in north central Utah

Productivity and food habits of the Barn Owl ( Tyto alba ) utilizing nest boxes in Juab, Utah, and Salt Lake counties, Utah, During 1979-1984 were examined. Average clutch size was 5.8 eggs for the 6-yr period; mean number fledged was 3.9 young per successful nest. While severe weather during the 1981-82 winter did not result in significant decrease in productivity during the 1982 breeding season, it may have resulted in a significant overproduction of female young. Barn Owls in north central Utah fed almost exclusively on mammalian species, particularly Microtus spp. Difference in clutch size between areas and years may be a response to availability as well as abundance of prey.     

Responses of Utah deer hunters to a checking station questionnaire

During the 1987 deer hunt 4,250 card questionnaires were distributed to Utah hunters at nine checking stations. Return rates varied from a mean 23% when cards were simply handed to hunters, to 50% when hunters' names and telephone numbers were taken. Results concerning methodology suggest that questionnaire surveys conducted from checking stations are efficient and accurate in obtaining hunter opinions. Questionnaire results indicated that most hunters rated the Utah deer hunt as moderately satisfactory, but may prefer alternative options that would result in a higher quality hunt. The majority of hunters indicated that hunter numbers should be limited to current levels or decreased. Unretrieved kill was reported as 21 deer per 100 hunters.     

Consumption of diffuse knapweed by two species of polyphagous grasshoppers (Orthoptera: Acrididae) in southern Idaho

Consumption of diffuse knapweed ( Centaurea diffusa Lam.) by 2 polyphagous grasshopper species, Melanoplus sanguinipes (F.) and Oedaleonotus enigma (Scudder), was studied using microhistological analysis of grasshopper crop contents. Grasshoppers were confined to cages containing C. diffusa and Sisymbrium altissimum L., a member of the mustard family known to be readily eaten by these 2 grasshopper species. Preference indices for knapweed were lower than for S. altissimum in 4 of 5 trials. An uncaged population of M. sanguinipes on a knapweed-infested site consumed only small amounts of knapweed until late summer when most other plants were senescent. Results suggested that diffuse knapweed s low palatability to generalist herbivores may confer to it a competitive advantage over other rangeland plants.     

European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), at the Hanford Reach National Monument, Washington State

The European earwig, Forficula auricularia L., was surveyed using pitfall traps at 3 sites at the Hanford Reach National Monument in south central Washington State. Pitfall traps were collected weekly from April 2002 through April 2003. The earwig was consistently taken during all months of the year at a disturbed, weedy site along the Columbia River (White Bluffs Ferry site) but was rare or not collected in 2 less-disturbed shrubsteppe habitats. Highest numbers occurred during April–May, when immatures accounted for the majority of the catch; immatures reached the adult stage during mid-July, and the species is univoltine at the site. Possible reasons why earwigs have not colonized the monument’s shrubsteppe habitat include the arid climate with lack of available moisture, especially for breeding purposes, and a lack of burrow sites. La tijereta Europea, Forficula auricularia L., fue estudiada usando trampas de caída en tres sitios del Hanford Reach National Monument en el sur del estado de Washington. Se colectaron los contenidos de las trampas de caída semanalmente desde abril de 2002 hasta abril de 2003. La tijereta apareció constantemente durante todos los meses del año en un sitio perturbado de vegetación herbácea en la orilla del Río Columbia (el lugar del antiguo transbordador White Bluffs) pero su colecta fue escasa o nula en dos hábitats de estepa arbustiva menos perturbados. Los mayores números ocurrieron durante abril y mayo cuando los organismos inmaduros representaron la mayoría de los especímenes capturados; éstos alcanzaron la etapa adulta a mediados de julio y la especie es univoltina en este sitio. Posibles causas de que las tijeretas no hayan colonizado el hábitat de estepa arbustiva del Monumento podrían incluir su clima árido carente de agua disponible, especialmente para la reproducción, y una falta de sitios para madrigueras.     

Passenger deletions generate therapeutic vulnerabilities in cancer

Inactivation of tumour-suppressor genes by homozygous deletion is a prototypic event in the cancer genome, yet such deletions often encompass neighbouring genes. We propose that homozygous deletions in such passenger genes can expose cancer-specific therapeutic vulnerabilities when the collaterally deleted gene is a member of a functionally redundant family of genes carrying out an essential function. The glycolytic gene enolase 1 (ENO1) in the 1p36 locus is deleted in glioblastoma (GBM), which is tolerated by the expression of ENO2. Here we show that short-hairpin-RNA-mediated silencing of ENO2 selectively inhibits growth, survival and the tumorigenic potential of ENO1-deleted GBM cells, and that the enolase inhibitor phosphonoacetohydroxamate is selectively toxic to ENO1-deleted GBM cells relative to ENO1-intact GBM cells or normal astrocytes. The principle of collateral vulnerability should be applicable to other passenger-deleted genes encoding functionally redundant essential activities and provide an effective treatment strategy for cancers containing such genomic events.     

Wnt-Ryk signalling mediates medial-lateral retinotectal topographic mapping

Computational modelling has suggested that at least two counteracting forces are required for establishing topographic maps. Ephrin-family proteins are required for both anterior-posterior and medial-lateral topographic mapping, but the opposing forces have not been well characterized. Wnt-family proteins are recently discovered axon guidance cues. We find that Wnt3 is expressed in a medial-lateral decreasing gradient in chick optic tectum and mouse superior colliculus. Retinal ganglion cell (RGC) axons from different dorsal-ventral positions showed graded and biphasic response to Wnt3 in a concentration-dependent manner. Wnt3 repulsion is mediated by Ryk, expressed in a ventral-to-dorsal decreasing gradient, whereas attraction of dorsal axons at lower Wnt3 concentrations is mediated by Frizzled(s). Overexpression of Wnt3 in the lateral tectum repelled the termination zones of dorsal RGC axons in vivo. Expression of a dominant-negative Ryk in dorsal RGC axons caused a medial shift of the termination zones, promoting medially directed interstitial branches and eliminating laterally directed branches. Therefore, a classical morphogen, Wnt3, acting as an axon guidance molecule, plays a role in retinotectal mapping along the medial-lateral axis, counterbalancing the medial-directed EphrinB1-EphB activity.     

Platensimycin is a selective FabF inhibitor with potent antibiotic properties

Bacterial infection remains a serious threat to human lives because of emerging resistance to existing antibiotics. Although the scientific community has avidly pursued the discovery of new antibiotics that interact with new targets, these efforts have met with limited success since the early 1960s. Here we report the discovery of platensimycin, a previously unknown class of antibiotics produced by Streptomyces platensis. Platensimycin demonstrates strong, broad-spectrum Gram-positive antibacterial activity by selectively inhibiting cellular lipid biosynthesis. We show that this anti-bacterial effect is exerted through the selective targeting of beta-ketoacyl-(acyl-carrier-protein (ACP)) synthase I/II (FabF/B) in the synthetic pathway of fatty acids. Direct binding assays show that platensimycin interacts specifically with the acyl-enzyme intermediate of the target protein, and X-ray crystallographic studies reveal that a specific conformational change that occurs on acylation must take place before the inhibitor can bind. Treatment with platensimycin eradicates Staphylococcus aureus infection in mice. Because of its unique mode of action, platensimycin shows no cross-resistance to other key antibiotic-resistant strains tested, including methicillin-resistant S. aureus, vancomycin-intermediate S. aureus and vancomycin-resistant enterococci. Platensimycin is the most potent inhibitor reported for the FabF/B condensing enzymes, and is the only inhibitor of these targets that shows broad-spectrum activity, in vivo efficacy and no observed toxicity.     

Identification of the primary gene defect at the cytochrome P450 CYP2D locus

The mammalian cytochrome P450-dependent monooxygenase system is involved in the metabolism of drugs and chemical carcinogens. The role of these enzymes in toxicological response is exemplified by an autosomal recessive polymorphism at the cytochrome P450 CYP2D6 debrisoquine hydroxylase locus which results in the severely compromised metabolism of at least 25 drugs, and which in some cases can lead to life-threatening side-effects. In addition, this polymorphism, which affects 8-10% of the caucasian population, has been associated with altered susceptibility to lung and bladder cancer. Here we report the identification of the primary mutation responsible for this metabolic defect and the development of a simple DNA-based genetic assay to allow both the identification of most individuals at risk of drug side-effects and clarification of the conflicting reports on the association of this polymorphism with cancer susceptibility.