Sex Ratio and Sexual Dimorphism in \u3ci\u3eFormica Exsectoides\u3c/i\u3e, the Allegheny Mound Ant (Hymenoptera: Formicidae)

We excavated 66 mounds from 6 populations of Formica exsectoides in Michigan jack pine, collecting sexual caste pupae for sex ratio estimates and measurement of dimorphism. Reproductive caste brood was present in only 37 ofthe 66 mounds, and presence of reproductive caste brood was associated with larger mound surface area. Females were heavier than males, but did not differ from males in energy density. Sexes did not differ in timing or rate of development. Sex ratio estimates based on individual mounds ranged from 1.0 (all male) to 0.08 (female·biased). Four of the six study populations were strongly male·biased, while sex ratio estimates for the remaining populations did not differ from equal investment. While this interpopulation variation may be caused by genetic factors, the equal investment populations were 10· cated in or near patches of clear·cut forest, suggesting that environmental impacts should be investigated

Seasonal Response of Workers of the Allegheny Mound Ant, \u3ci\u3eFormica Exsectoides\u3c/i\u3e (Hymenoptera: Formicidae) to Artificial Honeydews of Varying Nutritional Content

Field colonies of Allegheny mound ants, Formica exsectoides, were tested at monthly intervals throughout the summer to assess their preference for artificial honeydews containing varying compositions of sugars and amino acids. In choice tests, foragers significantly preferred high sugar honeydews early in the season, but shifted in mid-season to a strong preference for high amino acid honeydews. Late-season foragers slightly preferred sugars. When offered in equal concentrations, the honeydew sugar, melezitose, was consistently less attractive to foragers than sucrose. However both sugars were readily fed upon, and appeared to attract ants in an additive fashion. No single amino acid was significantly preferred; however the combination of asparagine, glutamine and serine was highly attractive during the mid-season sampling period. The seasonal switch in forager preference between sugars and amino acids coincides with an increase in the amount of actively growing brood

Signatures of four-particle correlations associated with exciton-carrier interactions in coherent spectroscopy on bulk GaAs

Transient four-wave mixing studies of bulk GaAs under conditions of broad bandwidth excitation of primarily interband transitions have enabled four-particle correlations tied to degenerate (exciton-exciton) and nondegenerate (exciton-carrier) interactions to be studied. Real two-dimensional Fourier-transform spectroscopy (2DFTS) spectra reveal a complex response at the heavy-hole exciton emission energy that varies with the absorption energy, ranging from dispersive on the diagonal, through absorptive for low-energy interband transitions to dispersive with the opposite sign for interband transitions high above band gap. Simulations using a multilevel model augmented by many-body effects provide excellent agreement with the 2DFTS experiments and indicate that excitation-induced dephasing (EID) and excitation-induced shift (EIS) affect degenerate and nondegenerate interactions equivalently, with stronger exciton-carrier coupling relative to exciton-exciton coupling by approximately an order of magnitude. These simulations also indicate that EID effects are three times stronger than EIS in contributing to the coherent response of the semiconductor

Did You Not Understand The Question Or Not? An Investigation Of Negatively Worded Questions In Survey Research

This study compared participant responses to negatively versus positively worded questionnaire statements.  The literature suggested that one could expect the wording of questionnaire items (i.e., negatively worded vs. positively worded) to influence participant responses to those scale items.  The study consisted of one control group and two experimental groups.   The Fashion Consciousness scale (Wilkes 1992;  Lumpkin and Darden 1982), a uni-dimensional, all-positive seven-item instrument was adapted for use in the study.  Three hypotheses regarding the factor structure and internal reliability of the scale were empirically investigated.  Results showed statistically significant differences in the psychometrics of the scale when negative or double negative wording was added to scale items.  Managerial implications are discussed

Clinical spirocercosis in a dog in the UK

A 2-year-old female neutered crossbreed dog was presented for evaluation of a 3-day history of haematemesis, melaena and hyporexia. The dog had been imported from a rescue centre in Hungary 4 months prior to presentation. Abdominal CT revealed the presence of a 3 cm×3 cm×4 cm diameter heterogenous intraluminal mass lesion in the gastric cardia, surrounding the ostium of the cardia and continuous with the distal oesophagus. The mass lesion was subsequently surgically resected. Histopathology of the gastric mass lesion was consistent with a Spirocerca lupi granuloma. The patient unfortunately developed a pyothorax and suffered cardiopulmonary arrest resulting in death 2 days postoperatively. To the authors’ knowledge, this is the first reported case of clinical spirocercosis reported in a dog in the UK

Where are the Baryons?

New, high resolution, large-scale, cosmological hydrodynamic galaxy formation simulations of a standard cold dark matter model (with a cosmological constant) are utilized to predict the distribution of baryons at the present and at moderate redshift. It is found that the average temperature of baryons is an increasing function of time, with most of the baryons at the present time having a temperature in the range 10^{5-7} K. Thus, not only is the universe dominated by dark matter, but more than one half of the normal matter is yet to be detected. Detection of this warm/hot gas poses an observational challenge, requiring sensitive EUV and X-ray satellites. Signatures include a soft, cosmic X-ray background, apparent warm components in hot clusters due to both intrinsic warm intra-cluster gas and warm inter-cluster gas projected onto clusters along the line of sight, absorption lines in X-ray and UV quasar spectra [e.g., O VI (1032,1038)A lines, OVII 574 eV line], strong emission lines (e.g., O VIII 653 eV line) and low redshift, broad, low column density \lya absorption lines. We estimate that approximately 1/4 of the extragalactic soft X-ray background (SXRB) (at 0.7 keV) arises from the warm/hot gas, half of it coming from $z<0.65$ and three-quarters from $z<1.00$, so the source regions should be identifiable on deep optical images.Comment: ApJ in press, revised (fig 3 is in jpg). Whole paper including fig3.ps can be obtained at "http://astro.princeton.edu/~cen/PAPERS_TO_APPEAR/64