Comparative Study of Life Histories, Laboratory Rearing, and Immature Stages of \u3ci\u3eEuschistus Servus\u3c/i\u3e and \u3ci\u3eEuschistus Variolarius\u3c/i\u3e (Hemiptera: Pentatomidae)

A comparative study was conducted of the field life histories of Euschistus servus and E. varialarius in southern Illinois, their life cycles under controlled laboratory conditions, and their immature stages. The results indicate that E. servus is bivoltine and E. variolarius is univoltine. Adults of both species emerged from overwintering sites during early April, began feeding and copulating on leaves of common mullein (Verbascum thapsus) and surrounding vegetation, and reproduced shortly thereafter. Neither eggs and first instars of either species, nor second instars of E. variolarius, were collected in the field. Seasonal occurrences of the adults and subsequent immature stages are discussed for each species. No individuals were found after the first week of November. Both species were reared on green beans (Phaseolus vulgaris) under a 16L:8D photoperiod and constant temperature of 23 ± 0.06° C. The incubation period averaged 5.8 days for E. servus and 5.4 days for E. variolanus. Durations of the 5 subsequent stadia averaged, respectively, 5, 6, 6.7, 9.3, and 11.5 days for E. servus, and 4.9,5.7,7.8,9.7, and 13.3 days for E. varialarius. Comparisons of incubation period and stadia between the two species showed that only the stadia for the first instars were not statistically different. Total developmental period was longer for E. varialarius than for E. servus. The external anatomy of the egg and each of the five nymphal instars is described for each species

The Stink Bugs (Hemiptera: Heteroptera: Pentatomidae) of Washington State

Froeschner (1988) recorded 23 species of stink bugs (Hemiptera: Heteroptera: Pentatomidae) from Washington State. Based on material primarily housed in the M. T. James Entomological Collection at Washington State University, the number of species is increased to 51. Three species recorded by Froeschner (1988) were not found in our collections: Apateticus crocatus (Uhler), Chlorochroa rossiana Buxton and Thomas, and Tepa rugulosa (Say). Species recorded from Washington State for the first time are: Apoecilus bracteatus (Fitch), Perillus bioculatus (Fabricius), Podisus maculiventris (Say), P. pallens (Stål), P. placidus Uhler, P. serieventris Uhler, Zicrona caerulea (Linnaeus), Halyomorpha halys (Stål), Brochymena quadripustulata (Fabricius), B. sulcata Van Duzee, Acrosternum hilare (Say), Aelia americana Dallas, Banasa euchlora Stål, B. tumidifrons Thomas and Yonke, Chlorochroa congrua Uhler, Coenus delius (Say), Cosmopepla uhleri Montandon, Dendrocoris pini Montandon, Euschistus servus (Say), E. tristigmus (Say), E. variolarius (Palisot), Holcostethus limbolarius (Say), Neottiglossa sulcifrons Stål, N. undata (Say), Prionosoma podopioides (Uhler), Tepa yerma (Rolston), Trichopepla grossa (Van Duzee), and Amaurochrous vanduzeei Barber and Sailer

Sgr A^*: A supermassive black hole or a spatially extended object?

We report here on a calculation of possible orbits of the fast moving infrared source S1 which has been recently observed by Eckart and Genzel (1997) near the Galactic center. It is shown that tracking of the orbit of S1 or any other fast moving star near Sgr A^* offers a possibility of distinguishing between the supermassive black hole and extended object scenarios of Sgr A^*. In our calculations we assumed that the extended object at the Galactic center is a non-baryonic ball made of degenerate, self-gravitating heavy neutrino matter, as it has been recently proposed by Tsiklauri & Viollier (1998a,b).Comment: AASTEX, 5 postscript figs., submitted to ApJ Let

On the Formation of Degenerate Heavy Neutrino Stars

The dynamics of a self-gravitating cold Fermi gas is described using the analogy with an interacting self-gravitating Bose condensate having the same Thomas-Fermi limit. The dissipationless formation of a heavy neutrino star through gravitational collapse and ejection of matter is demonstrated numerically. Such neutrino stars offer an alternative to black holes for the supermassive compact dark objects at the centers of galaxies.Comment: 11 pages, 3 figures, Latex, elsart.sty, fig1 improved, to appear in Phys. Lett.

Examining the early distribution of the artemisinin-resistant Plasmodium falciparum kelch13 R561H mutation in areas of higher transmission in Rwanda

BACKGROUND: Artemisinin resistance mutations in Plasmodium falciparum kelch13 (Pfk13) have begun to emerge in Africa, with Pfk13-R561H being the first reported in Rwanda in 2014, but limited sampling left questions about its early distribution and origin. METHODS: We genotyped P. falciparum positive dried blood spot (DBS) samples from a nationally representative 2014-2015 Rwanda Demographic Health Surveys (DHS) HIV study. DBS were subsampled from DHS sampling clusters with >15% P. falciparum prevalence, as determined by rapid testing or microscopy done during the DHS study (n clusters = 67, n samples = 1873). RESULTS: We detected 476 parasitemias among 1873 residual blood spots from a 2014-2015 Rwanda Demographic Health Survey. We sequenced 351 samples: 341/351 were wild-type (97.03% weighted), and 4 samples (1.34% weighted) harbored R561H that were significantly spatially clustered. Other nonsynonymous mutations found were V555A (3), C532W (1), and G533A (1). CONCLUSIONS: Our study better defines the early distribution of R561H in Rwanda. Previous studies only observed the mutation in Masaka as of 2014, but our study indicates its presence in higher-transmission regions in the southeast of the country at that time

The Pioneer anomaly in the context of the braneworld scenario

We examine the Pioneer anomaly - a reported anomalous acceleration affecting the Pioneer 10/11, Galileo and Ulysses spacecrafts - in the context of a braneworld scenario. We show that effects due to the radion field cannot account for the anomaly, but that a scalar field with an appropriate potential is able to explain the phenomena. Implications and features of our solution are analyzed.Comment: Final version to appear at Classical & Quantum Gravity. Plainlatex 19 page

The motion of stars near the Galactic center: A comparison of the black hole and fermion ball scenarios

After a discussion of the properties of degenerate fermion balls, we analyze the orbits of the stars S0-1 and S0-2, which have the smallest projected distances to Sgr A*, in the supermassive black hole as well as in the fermion ball scenarios of the Galactic center. It is shown that both scenarios are consistent with the data, as measured during the last six years by Genzel et al. and Ghez et al. The free parameters of the projected orbit of a star are the unknown components of its velocity v_z and distance z to Sgr A* in 1995.4, with the z-axis being in the line of sight. We show, in the case of S0-1 and S0-2, that the z-v_z phase-space which fits the data, is much larger for the fermion ball than for the black hole scenario. Future measurements of the positions or radial velocities of S0-1 and S0-2 could reduce this allowed phase-space and eventually rule out one of the currently acceptable scenarios. This may shed some light into the nature of the supermassive compact dark object, or dark matter in general at the center of our Galaxy.Comment: 30 pages, 12 figures, Latex, aasms4 styl

Model independent analysis of dark matter points to a particle mass at the keV scale

We present a model independent analysis of dark matter (DM) both decoupling ultra relativistic (UR) and non-relativistic (NR) based in the phase-space density D = rho_{DM}/sigma^3_{DM}. We derive explicit formulas for the DM particle mass m and for the number of ultra relativistic degrees of freedom g_d at decoupling. We find that for DM particles decoupling UR both at local thermal equilibrium (LTE) and out of LTE, m turns to be at the keV scale. For example, for DM Majorana fermions decoupling at LTE the mass results m ~ 0.85 keV. For DM particles decoupling NR, sqrt{m T_d} results in the keV scale (T_d is the decoupling temperature) and the m value is consistent with the keV scale. In all cases, DM turns to be cold DM (CDM). Also, lower and upper bounds on the DM annihilation cross-section for NR decoupling are derived. We evaluate the free-streaming (Jeans') length and Jeans' mass: they result independent of the type of DM except for the DM self-gravity dynamics. The free-streaming length today results in the kpc range. These results are based on our theoretical analysis, astronomical observations of dwarf spheroidal satellite galaxies in the Milky Way and N-body numerical simulations. We analyze and discuss the results on D from analytic approximate formulas both for linear fluctuations and the (non-linear) spherical model and from N-body simulations results. We obtain in this way upper bounds for the DM particle mass which all result below the 100 keV range.Comment: 11 pages, 2 figures. Expanded version to be published in Monthly Notices of the Royal Astronomical Societ

Dark matter and dark energy accretion onto intermediate-mass black holes

In this work we investigate the accretion of cosmological fluids onto an intermediate-mass black hole at the centre of a globular cluster, focusing on the influence of the parent stellar system on the accretion flow. We show that the accretion of cosmic background radiation and the so-called dark energy onto an intermediate-mass black hole is negligible. On the other hand, if cold dark matter has a nonvanishing pressure, the accretion of dark matter is large enough to increase the black hole mass well beyond the present observed upper limits. We conclude that either intermediate-mass black holes do not exist, or dark matter does not exist, or it is not strictly collisionless. In the latter case, we set a lower limit for the parameter of the cold dark matter equation of state.Comment: 5 pages, 3 figures, Published in MNRA