The ionizing sources of luminous compact HII regions in the RCW106 and RCW122 clouds

Given the rarity of young O star candidates, compact HII regions embedded in dense molecular cores continue to serve as potential sites to peer into the details of high-mass star formation. To uncover the ionizing sources of the most luminous and compact HII regions embedded in the RCW106 and RCW122 giant molecular clouds, known to be relatively nearby (2-4 kpc) and isolated, thus providing an opportunity to examine spatial scales of a few hundred to a thousand AU in size. High spatial resolution (0.3"), mid-infrared spectra (R=350), including the fine structure lines [ArIII] and [NeII], were obtained for four luminous compact HII regions, embedded inside the dense cores within the RCW106 and RCW122 molecular cloud complexes. At this resolution, these targets reveal point-like sources surrounded by nebulosity of different morphologies, uncovering details at spatial dimensions of <1000AU. The point-like sources display [ArIII] and [NeII] lines - the ratios of which are used to estimate the temperature of the embedded sources. The derived temperatures are indicative of mid-late O type objects for all the sources with [ArIII] emission. Previously known characteristics of these targets from the literature, including evidence of disk or accretion suggest that the identified sources may grow more to become early-type O stars by the end of the star formation process

The Dynamics of Assortative Mating in Germany

Basutoland Basuto house, 319ColorVolume 87, Page 1

The Dynamics of Assortative Mating in Germany

This paper examines the patterns of educational assortative mating in East and West Germany. In the literature it is well known that individuals do not mate randomly with respect to social and cultural traits, and that highly assortative mating can lead to polarization and exacerbate economic inequality. For Germany, little is known about actual patterns of marriage formation along educational lines. Our empirical analysis for Germany shows that educational assortative mating has increased significantly for East and West Germany during the last 15 and 30 years, respectively. To control for secular increases in educational attainment we apply different log-linear methods, leading to the conclusion that the observed changes in assortative mating in East and West Germany might be explained by changes in partner preferences. Especially within the group of low educated persons, the preferences for a homogamous partnership seems to have increased over time.In unserer empirischen Analyse untersuchen wir Trends in bildungsselektivem Heiratsverhalten (Homogamie) in Ost- und Westdeutschland. In der Literatur ist hinlänglich bekannt, dass Individuen bezogen auf soziale und kulturelle Eigenschaften nicht zufällig heiraten und dass selektives Heiratsverhalten zu einer Polarisierung und zu einer Verschärfung der Ungleichheit führen kann. Für Deutschland existiert bisher wenig Evidenz für bildungsselektives Heiratsverhalten. Unter Verwendung der Daten des deutschen Mikrozensus zeigen wir, dass die Homogamie in Ost- und Westdeutschland in den letzten 15 bzw. 30 Jahren signifikant angestiegen ist. Log-lineare Modelle liefern Belege, dass die beobachteten Veränderungen in der Partnerwahl durch Veränderungen in den Präferenzen hinsichtlich der Bildung des Partners erklärt werden können. Insbesondere unter Ehegatten mit niedrigem Bildungsstand stieg die Neigung, eine Person mit gleichem Bildungsstand zu heiraten

Global biogeography, cryptic species and systematic issues in the shrimp genus <i>Hippolyte</i> Leach, 1814 (Decapoda: Caridea: Hippolytidae) by multimarker analyses

Hippolyte is a genus of small bodied marine shrimps, with a global distribution. Here, we studied the phylogenetic and biogeographic relationships amongst the species of this genus with two mitochondrial and two nuclear markers, using Bayesian Inference, Maximum Likelihood, genetic divergence, molecular clock and S-DIVA. In addition, the Indo-West Pacific genus Alcyonohippolyte was included. Based on sequences from 57 specimens of 27 species, we recovered a robust biogeographic scenario that shows the Indo-West Pacific as the probable ancestral area of the genus Hippolyte, which emerged in the Paleocene, followed by dispersal in three general directions: (1) South Pacific, (2) eastern Atlantic and Mediterranean Sea and (3) Americas, the latter with a primary colonization in the eastern Pacific followed by a radiation into the western Atlantic. Our analysis reveals that the species of the H. ventricosa group do not constitute a monophyletic group and Alcyonohippolyte does not constitute a reciprocally monophyletic group to Hippolyte, with both genera herein synonimised. The relationships and systematic status of several transisthmian and Atlantic species are clarified

Synalpheus pinkfloydi sp. nov., a new pistol shrimp from the tropical eastern Pacific (Decapoda: Alpheidae)

A new, conspicuously coloured species of the alpheid genus Synalpheus Spence Bate, 1888, is described based on material collected on the Pacific coast of Panama. Synalpheus pinkfloydi sp. nov. is closely related to the western Atlantic S. antillensis Coutière, 1909, the two taxa being transisthmian, cryptic sister species. Both species are characterised by the distal areas of their major and minor chelae coloured in an intense, almost glowing pink-red. The morphological differences between S. pinkfloydi sp. nov. and S. antillensis Coutière, 1909 are subtle, being limited to the slightly different proportions of the merus of both chelipeds, distodorsal armature of the major cheliped merus, relative length of the antennal scaphocerite, and body size. However, they are genetically different with a 10.2% sequence divergence in COI. Based on molecular clock estimates, these transisthmian taxa diverged around 6.8–7.8 mya, i.e. well before the final closure of the Isthmus of Panama 2.5–3 mya

Fixation locations when grasping partly occluded objects

When grasping an object, subjects tend to look at the contact positions of the digits (A. M. Brouwer, V. H. Franz, D. Kerzel, & K. R. Gegenfurtner, 2005; R. S. Johansson, G. Westling, A. Bäckström, & J. R. Flanagan, 2001). However, these contact positions are not always visible due to occlusion. Subjects might look at occluded parts to determine the location of the contact positions based on extrapolated information. On the other hand, subjects might avoid looking at occluded parts since no object information can be gathered there. To find out where subjects fixate when grasping occluded objects, we let them grasp flat shapes with the index finger and thumb at predefined contact positions. Either the contact position of the thumb or the finger or both was occluded. In a control condition, a part of the object that does not involve the contact positions was occluded. The results showed that subjects did look at occluded object parts, suggesting that they used extrapolated object information for grasping. Additionally, they preferred to look in the direction of the index finger. When the contact position of the index finger was occluded, this tendency was inhibited. Thus, an occluder does not prevent fixations on occluded object parts, but it does affect fixation locations especially in conditions where the preferred fixation location is occluded. © ARVO