The mechanism of nestmate discrimination in the tropical social wasp Ropalidia marginata and its implications for the evolution of sociality

We have demonstrated that females of the primitively eusocial tropical wasp Ropalidia marginata can discriminate nestmates from nonnestmates outside the context of their nests. This was accomplished by recroding all behavioural interactions in a neutral arena and comparing tolerance levels. In order for these wasps to make such a discrimination, however, it was essential that after eclosion both the discriminated and the discriminating animals were exposed to their respective natal nests and nestmates. The results suggest that both recognition labels and templates are acquired by the animals from sources outside their body, perhaps from their nest or nestmates. It is thus unlikely that different genetic lines within a colony can be distinguished. We conclude, therefore, that genetic asymmetries created by haplodiploidy, but often broken down by multiple mating and polygyny, are not restored by preferential altruism towards full rather than half sisters by means of kin recognition. Hence we recommend caution in ascribing the multiple origins of eusociality in the Hymenoptera to haplodiploidy

Surfactant-induced stabilization of four-coordinated hemes in reconstituted hemoglobins

A transition from 5-coordination to 4-coordination metal centres of porphyrins in carbonmonoxy Fe(II), Cu(II) and Ni(II) hemoglobins is observed as a consequence of ionic surfactant interactions with metalloproteins through UV-Vis studies. SDS (anionic) and CTAB (cationic) surfactants are used. Values of heme partition coefficient (K) between globin and surfactant show that, in both CTAB and SDS, partitioning increases proportionately with surfactant concentration for a fixed concentration of hemoglobin. The interactions seem to be mainly hydrophobic in nature with metalloproteins, though coordination and coulombic interactions may also play a minor role in CTAB and SDS respectively. The present study provides new insight into reconstituted hemoglobin-surfactant interaction

A Diagnosis of Insomnia Is Associated With Differential Expression of Sleep-Regulating Genes in Military Personnel

Sleep disturbance is a common and disturbing symptom in military personnel, with many individuals progressing to the development of insomnia, which is characterized by increased arousals, wakefulness after sleep onset, and distorted sleep architecture. The molecular mechanisms underlying insomnia remain elusive, limiting future therapeutic development to address this critical issue. We examined whole gene expression profiles associated with insomnia. We compared subjects with insomnia (n = 25) to controls (n = 13) without insomnia using microarray gene expression profiles obtained from peripheral samples of whole blood obtained from military personnel. Compared to controls, participants with insomnia had differential expression of 44 transcripts from 43 identified genes. Among the identified genes, urotensin 2 was downregulated by more than 6 times in insomnia participants, and the fold-change remained significant after controlling for depression, posttraumatic stress disorder, and medication use. Urotensin 2 is involved in regulation of orexin A and B activity and rapid eye movement during sleep. These findings suggest that differential expression of these sleep-regulating genes contributes to symptoms of insomnia and, specifically, that switching between rapid eye movement and nonrapid eye movement sleep stages underlies insomnia symptoms. Future work to identify therapeutic agents that are able to regulate these pathways may provide novel treatments for insomnia

Silicon Etching Characteristics in Modified TMAH Solution

In the present work, we have studied the etching characteristics of Si {100} and Si{110} in modified low concentration TMAH solution by adding different concentrations of NH 2 OH. The etch rate of silicon and thermal oxide, and etched surface morphology, which are important parameters to be known in the fabrication of MEMS structures using silicon wet bulk micromachining, have been studied in modified TMAH solution. In addition, the effect of aging time of the etchant solution on the etching characteristics is investigated