Allometry of Workers of the Fire Ant, Solenopsis invicta

The relationship between worker body size and the shape of their body parts was explored in the polymorphic ant, Solenopsis invicta. The data consisted of 20 measurements of body parts as well as sums of some of these measurements. Size-free shape variables were created by taking the ratios of relevant measures. After log-transformation, these ratios were regressed against the logarithm of total body length, or against the log of the size of the parent part. Slopes of zero indicated that shape did not change with size, and non-zero slopes signaled a size-related change of shape. Across the range of worker sizes, the head length retained a constant proportion to body length, but relative headwidth increased such that head shape changed from a barrel-profile to a somewhat heart-shaped profile. Antennae became relatively smaller, with the club contributing more to this decline than the other parts. The alinotum became relatively shorter and higher (more humped), and the gaster increased in both relative width and length, and therefore in volume. All three pairs of legs were isometric to body length. The component parts of the legs, with one exception, were isometric to their own total leg length. The body of S. invicta Abbreviation: / HL: head length BL: body length HW1: width across the eyes HW2: width above the eyes HW3: width below the eye

Determinants of Effective Population Size for Loci with Different Modes of Inheritance

Here we report an assessment of the determinants of effective population size (Ne) in species with overlapping generations. Specifically, we used a stochastic demographic model to investigate the influence of different life-history variables on Ne/N (where N = population census number) and the influence of sex differences in life-history variables on Ne for loci with dif¬ferent modes of inheritance. We applied an individual-based modeling approach to two datasets: one from a natural popu¬lation of savannah baboons (Papio cynocephalus) in the Amboseli basin of southern Kenya and one from a human tribal pop¬ulation (the Gainj of Papua New Guinea). Simulation-based estimates of Ne/N averaged 0.329 for the Amboseli baboon population (SD = 0.116, 95% CI = 0.172 – 0.537) and 0.786 for the Gainj (SD = 0.184, 95% CI = 0.498 – 1.115). Although variance in male fitness had a substantial impact on Ne/N in each of the two primate populations, ratios of Ne values for au¬tosomal and sex-linked loci exhibited no significant departures from Poisson-expected values. In each case, similarities in sex-specific Ne values were attributable to the unexpectedly high variance in female fitness. Variance in male fitness resulted primarily from age-dependent variance in reproductive success, whereas variance in female fitness resulted primarily from stochastic variance in survival during the reproductive phase

Adaptive online deployment for resource constrained mobile smart clients

Nowadays mobile devices are more and more used as a platform for applications. Contrary to prior generation handheld devices configured with a predefined set of applications, today leading edge devices provide a platform for flexible and customized application deployment. However, these applications have to deal with the limitations (e.g. CPU speed, memory) of these mobile devices and thus cannot handle complex tasks. In order to cope with the handheld limitations and the ever changing device context (e.g. network connections, remaining battery time, etc.) we present a middleware solution that dynamically offloads parts of the software to the most appropriate server. Without a priori knowledge of the application, the optimal deployment is calculated, that lowers the cpu usage at the mobile client, whilst keeping the used bandwidth minimal. The information needed to calculate this optimum is gathered on the fly from runtime information. Experimental results show that the proposed solution enables effective execution of complex applications in a constrained environment. Moreover, we demonstrate that the overhead from the middleware components is below 2%

Collective psychological ownership and reconciliation in territorial conflicts

Collective psychological ownership refers to people’s perception that an object, place, or idea belongs to their own group. We considered this concept in the context of territorial conflicts and proposed that (1) collective psychological ownership is distinct from place attachment, (2) higher ingroup identifiers are more likely to claim collective ownership and feel attached to the territory, yet (3) only ownership claims are related to lower support for reconciliation. These hypotheses were tested in two studies using structural equation modelling. Study 1 addressed the Kosovo conflict, based on Serbian participants living in Serbia (N = 264). We found that collective psychological ownership and place attachment were distinct. Moreover, higher Serbian identifiers had a stronger sense of collective ownership of Kosovo and were more attached to it. Those with stronger feelings of collective ownership supported reconciliation with Albanians less, while place attachment did not hinder reconciliation. Study 2 replicated these findings among a new sample of Serbs in Serbia (N = 173), among Serbs in Kosovo (N = 129), and in two other conflict settings: among Greek Cypriots in Cyprus (N = 135) and Jews in Israel (N = 109). Altogether, we provide evidence that collective psychological ownership can represent an obstacle to reconciliation in conflict regions

OPTIS - a satellite-based test of Special and General Relativity

A new satellite based test of Special and General Relativity is proposed. For the Michelson-Morley experiment we expect an improvement of at least three orders of magnitude, and for the Kennedy-Thorndike experiment an improvement of more than one order of magnitude. Furthermore, an improvement by two orders of the test of the universality of the gravitational red shift by comparison of an atomic clock with an optical clock is projected. The tests are based on ultrastable optical cavities, an atomic clock and a comb generator.Comment: To appear in Class. Quantum Gra

Target prediction for small, noncoding RNAs in bacteria

Many small, noncoding RNAs in bacteria act as post-transcriptional regulators by basepairing with target mRNAs. While the number of characterized small RNAs (sRNAs) has steadily increased, only a limited number of the corresponding mRNA targets have been identified. Here we present a program, TargetRNA, that predicts the targets of these bacterial RNA regulators. The program was evaluated by assessing whether previously known targets could be identified. The program was then used to predict targets for the Escherichia coli RNAs RyhB, OmrA, OmrB and OxyS, and the predictions were compared with changes in whole genome expression patterns observed upon expression of the sRNAs. Our results show that TargetRNA is a useful tool for finding mRNA targets of sRNAs, although its rate of success varies between sRNAs