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Chiefly tablesIncludes bibliographical referencesSupported in part by the National Institute of Education under contract no. US-NIE-C-400-76-011

Temporal and Spatial Distribution of the Oriental Beetle (Coleoptera: Scarabaeidae) in a Golf Course Environment

The mating season of the oriental beetle, Exomala orientalis (Waterhouse), in 1994 and 1995 at Bethpage State Park, Farmingdale, NY (40° 45′ N, 73° 28′ W) began in the middle of June, peaked in the 1st wk of July, and ended in the middle of August. There were differences in the emergence schedule among fairways as well as local differences between roughs and fairway. Both sexes were most active around sunset on shorter-cut turf (i.e., fairways, greens, and tees, versus roughs), and the few individuals seen during the daylight hours were mostly males. These males were generally found perched on vegetation at the border of the fairway. Feeding was not observed, except on flowers by females devoid of mature eggs. This study confirms our observations on the pattern of activity in an earlier study conducted with the use of synthetic pheromone traps. It also explains the difficulty encountered by earlier workers in finding adults of this insect in the field. Implications of the above findings on the management of the oriental beetle are discusse

Stability of small amplitude normal modes of a Bose-Einstein condensate with a singly quantized vortex confined in an optical lattice

We study the dynamics of a BEC with a singly quantized vortex, placed in the combined potential of a 1-D (2-D) optical lattice and an axi-symmetric harmonic trap. A time-dependent variational Lagrangian analysis shows that an optical lattice helps to stabilize the vortex which in absence of the optical lattice is unstable. We find that the normal modes are stable only if the depth of the optical potential is more than a certain critical value. This critical value of the optical potential depends on the interaction parameter.In general higher the interaction parameter,lower the value of the optical potential required to stabilize the vortex. The BEC with the singly quantized vortex is found to be relatively more unstable in a 2-D optical lattice compared to a 1-D optical lattice.Comment: Revised version with 11 pages including 1 figur

The alpha1 subunit of the GABA(A) receptor modulates fear learning and plasticity in the lateral amygdala.

Synaptic plasticity in the amygdala is essential for emotional learning. Fear conditioning, for example, depends on changes in excitatory transmission that occur following NMDA receptor activation and AMPA receptor modification in this region. The role of these and other glutamatergic mechanisms have been studied extensively in this circuit while relatively little is known about the contribution of inhibitory transmission. The current experiments addressed this issue by examining the role of the GABA(A) receptor subunit alpha1 in fear learning and plasticity. We first confirmed previous findings that the alpha1 subunit is highly expressed in the lateral nucleus of the amygdala. Consistent with this observation, genetic deletion of this subunit selectively enhanced plasticity in the lateral amygdala and increased auditory fear conditioning. Mice with selective deletion of alpha1 in excitatory cells did not exhibit enhanced learning. Finally, infusion of a alpha1 receptor antagonist into the lateral amygdala selectively impaired auditory fear learning. Together, these results suggest that inhibitory transmission mediated by alpha1-containing GABA(A) receptors plays a critical role in amygdala plasticity and fear learning

Vortex stabilization in a small rotating asymmetric Bose-Einstein condensate

We use a variational method to investigate the ground-state phase diagram of a small, asymmetric Bose-Einstein condensate with respect to the dimensionless interparticle interaction strength $\gamma$ and the applied external rotation speed $\Omega$. For a given $\gamma$, the transition lines between no-vortex and vortex states are shifted toward higher $\Omega$ relative to those for the symmetric case. We also find a re-entrant behavior, where the number of vortex cores can decrease for large $\Omega$. In addition, stabilizing a vortex in a rotating asymmetric trap requires a minimum interaction strength. For a given asymmetry, the evolution of the variational parameters with increasing $\Omega$ shows two different types of transitions (sharp or continuous), depending on the strength of the interaction. We also investigate transitions to states with higher vorticity; the corresponding angular momentum increases continuously as a function of $\Omega$

Stability of a vortex in a small trapped Bose-Einstein condensate

A second-order expansion of the Gross-Pitaevskii equation in the interaction parameter determines the thermodynamic critical angular velocity Omega_c for the creation of a vortex in a small axisymmetric condensate. Similarly, a second-order expansion of the Bogoliubov equations determines the (negative) frequency omega_a of the anomalous mode. Although Omega_c = -omega_a through first order, the second-order contributions ensure that the absolute value |omega_a| is always smaller than the critical angular velocity Omega_c. With increasing external rotation Omega, the dynamical instability of the condensate with a vortex disappears at Omega*=|omega_a|, whereas the vortex state becomes energetically stable at the larger value Omega_c. Both second-order contributions depend explicitly on the axial anisotropy of the trap. The appearance of a local minimum of the free energy for a vortex at the center determines the metastable angular velocity Omega_m. A variational calculation yields Omega_m=|\omega_a| to first order (hence Omega_m also coincides with the critical angular velocity Omega_c to this order). Qualitatively, the scenario for the onset of stability in the weak-coupling limit is the same as that found in the strong-coupling (Thomas-Fermi) limit.Comment: 8 pages, RevTe

The response of VEGF-stimulated endothelial cells to angiostatic molecules is substrate-dependent

BACKGROUND: The microenvironment surrounding cells can exert multiple effects on their biological responses. In particular the extracellular matrix surrounding cells can profoundly influence their behavior. It has been shown that the extracellular matrix composition in tumors is vastly different than that found in normal tissue with increased amounts of certain matrices such as collagen I. It has been previously demonstrated that VEGF stimulation of endothelial cells growing on type I collagen results in the induction of bcl-2 expression and enhanced endothelial cell survival. We sought to investigate whether this increased endothelial cell survival resulted in the failure of angiostatic molecules to inhibit angiogenesis. RESULTS: We now demonstrate that VEGF-induced survival on collagen I impairs the ability of three known angiostatic molecules, TSP-1, IP-10 and endostatin to inhibit endothelial cell proliferation. Apoptosis of endothelial cells, growing on collagen I, induced by TSP-1 and IP-10 was also inhibited following VEGF stimulation. In contrast, endostatin induced apoptosis in these same cells. Further analysis determined that endostatin did not decrease the expression of bcl-2 nor did it increase activation of caspase-3 in the presence of VEGF. Alternatively, it appeared that in the presence of VEGF, endostatin induced the activation of caspase-8 in endothelial cells grown on collagen I. Furthermore, only endostatin had the ability to inhibit VEGF-induced sprout formation in collagen I gels. CONCLUSION: These data suggest that TSP-1, IP-10 and endostatin inhibit endothelial cells via different mechanisms and that only endostatin is effective in inhibiting angiogenic activities in the presence of collagen I. Our results suggest that the efficacy of angiostatic treatments may be impaired depending on the context of the extracellular matrix within the tumor environment and thus could impede the efficacy of angiostatic therapies

Ammonium Carbonate Is More Attractive Than Apple and Hawthorn Fruit Volatile Lures to Rhagoletis pomonella (Diptera: Tephritidae) in Washington State

The apple maggot fly, Rhagoletis pomonella (Walsh), is an introduced, quarantine pest of apple (Malus domestica Borkhausen) in the Pacific Northwest of the United States. In the eastern United States where the fly is native, fruit volatiles have been reported to be more attractive than ammonia compounds to R. pomonella. However, the opposite may be true in the western United States. Here, we determined whether newly identified western apple and western hawthorn fruit volatiles are more attractive than ammonium carbonate (AC) to R. pomonella in apple, black hawthorn, and ornamental hawthorn trees in western Washington State. In all three host trees, sticky red sphere or yellow panel traps baited with AC generally caught more flies than traps baited with lures containing the four newly developed fruit blends (modified eastern apple, western apple, western ornamental hawthorn, and western black hawthorn) or two older blends (eastern apple and eastern downy hawthorn). Fruit volatiles also displayed more variation among trapping studies conducted at different sites, in different host trees, and across years than AC. The results imply that traps baited with AC represent the best approach to monitoring R. pomonella in Washington Stat

Stability of rotating states in a weakly-interacting Bose-Einstein condensate

We investigate the lowest state of a rotating, weakly-interacting Bose-Einstein condensate trapped in a harmonic confining potential that is driven by an infinitesimally asymmetric perturbation. Although in an axially-symmetric confining potential the gas has an axially-symmetric single-particle density distribution, we show that in the presence of the small asymmetric perturbation its lowest state is the one given by the mean-field approximation, which is a broken-symmetric state. We also estimate the rate of relaxation of angular momentum when the gas is no longer driven by the asymmetric perturbation and identify two regimes of "slow" and "fast" relaxation. States of certain symmetry are found to be more robust.Comment: 6 pages, RevTe