Deletion of steroid 5 alpha-reductase 2 gene in male pseudohermaphroditism

The conversion of testosterone into dihydrotestosterone by steroid 5 alpha-reductase is a key reaction in androgen action, and is essential both for the formation of the male phenotype during embryogenesis and for androgen-mediated growth of tissues such as the prostate. Single gene defects that impair this conversion lead to pseudohermaphroditism in which 46X,Y males have male internal urogenital tracts, but female external genitalia. We have described the isolation of a human 5 alpha-reductase complementary DNA from prostate. Subsequent cloning and genetic studies showed that this gene (designated 5 alpha-reductase 1) was normal in patients with 5 alpha-reductase deficiency. We report here the isolation of a second 5 alpha-reductase cDNA by expression cloning and the polymerase chain reaction. The biochemical and pharmacological properties of this cDNA-encoded enzyme (designated 5 alpha-reductase 2) are consistent with it being the major isozyme in genital tissue. A deletion in this gene is present in two related individuals with male pseudohermaphroditism caused by 5 alpha-reductase deficiency. These results verify the existence of at least two 5 alpha-reductases in man and provide insight into a fundamental hormone-mediated event in male sexual differentiation.     

Simulations of the formation, evolution and clustering of galaxies and quasars

The cold dark matter model has become the leading theoretical picture for the formation of structure in the Universe. This model, together with the theory of cosmic inflation, makes a clear prediction for the initial conditions for structure formation and predicts that structures grow hierarchically through gravitational instability. Testing this model requires that the precise measurements delivered by galaxy surveys can be compared to robust and equally precise theoretical calculations. Here we present a simulation of the growth of dark matter structure using 2,160(3) particles, following them from redshift z = 127 to the present in a cube-shaped region 2.230 billion lightyears on a side. In postprocessing, we also follow the formation and evolution of the galaxies and quasars. We show that baryon-induced features in the initial conditions of the Universe are reflected in distorted form in the low-redshift galaxy distribution, an effect that can be used to constrain the nature of dark energy with future generations of observational surveys of galaxies.     

Attack and brood production by the Douglas-fir beetle (Coleoptera: Scolytidae) in Douglas-fir, Pseudotsuga menziesii var. glauca (Pinaceae), following a wildfire

In 1994 ground fire ignited in forests of Douglas-fir, Pseudotsuga menziesii var. glauca (Mirb.) Franco, on Beaver Mountain, Utah. The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, attacked a range of moderately fire-injured host conifers in 1995. Logistic regression models run for 1995 data illustrated that 1 year after the fire event the Douglas-fir beetle selected and attacked large-diameter Douglas-fir with 60%-80% bole char, 60%-80% crown volume scorch, and 50%-70% probability of mortality due to fire. In 1996 beetle preference shifted to smallerdiameter trees with lighter fire injury, because most large, fire-damaged conifers were colonized by beetles in 1995. Although beetle populations did not reach outbreak proportions outside the fire boundary, host selection shifted to green trees in 1997 along the burn perimeter. Log linear analysis indicated that increased brood production was conditioned by increased diameter and moderate fire damage to the trees.     

Seed and cone insects associated with Pinus monophylla in the Raft River Mountains, Utah

Yearly variation in numbers of cones produced by western white pine was found to affect the population level of the mountain pine cone beetle. In years when cone production is moderate to heavy, beetle populations increase. Increasing beetle populations are ultimately limited by poor cone crops, which increase competition for nutrients and oviposition sites. Variability in western white pine cone production is regarded as the most important factor regulating populations of the mountain pine cone beetle.        

Raptors of the Uinta National Forest, Utah

The past and present use of the Uinta National Forest by birds of prey was determined from historical records and surveys conducted during 1973, 1974, and 1975. Data describing the history, present status, and physical characteristics of each nest site were collected, along with the type and intensivity of human activity within a half - mile radius of the nest. In addition, limited data on fall migration of raptors along the Wasatch Front and the food habits of Golden Eagles are presented. Management guidelines, based on the results of this study, are proposed.     

Transiting circumbinary planets Kepler-34 b and Kepler-35 b

Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated, the existence of a 'circumbinary planet' orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289?days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun's mass) every 131?days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ～1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.