The Effects of Divorce and Conflict On Academic Achievement

The influential aspects of a parental divorce on children may not solely depend upon the divorce but may include other variables such as exposure to high levels of parental and familial conflict. How these experiences are manifested within a child is an important question to be answered. In the past it was believed that the experiences related to parental divorce decreased the child\u27s ability to compete scholastically with peers that came from non-divorced families. What this study examined was whether there is a difference between hindering· learning and hindering performance. To detect differences between the two, it is proposed that decreases in the child\u27s grade point average (GPA) reflect performance, a lack of knowledge application. In order to determine whether or not a lack of learning has occurred, one must look at the child\u27s performance on a standardized achievement test (i.e. the Iowa Tests of Educational Development/ITED). This study examined the effects of divorce and conflict on GPA and ITED scores in an attempt to show where and when changes in the child\u27s learning take place. It was found that presence of parental divorce or perceived familial conflict has a detrimental effect on a student\u27s academic achievement as measured by GPA. Additionally, it was predicted and found that family constellation and gender congruence mediate the performance as measured by GPA. Students that expressed high levels of perceived conflict and had a parental remarriage of a same­ sex custodial parent showed significantly lower academic achievement

Hedonists, Ladies and Larrikins: Crime, Prostitution and the 1987 America\u27s Cup

This article examines crime and prostitution within the context of the hosting of a hallmark tourist event--the 1987 America\u27s Cup Defence in Fremantle, Western Australia. Although there are substantial difficulties in undertaking research on prostitution, the authors observe there was a substantial increase in prostitution in the Perth metropolitan area during the Cup defence. Similarly, official police statistics indicate that criminal activity was also affected by the hosting of the Cup. However, evidence also suggests that the Cup may have contributed to a more permanent impact on social mores and the expression of anti-social behaviour in Perth and Fremantle

Acoustic, psychophysical, and neuroimaging measurements of the effectiveness of active cancellation during auditory functional magnetic resonance imaging

Functional magnetic resonance imaging (fMRI) is one of the principal neuroimaging techniques for studying human audition, but it generates an intense background sound which hinders listening performance and confounds measures of the auditory response. This paper reports the perceptual effects of an active noise control (ANC) system that operates in the electromagnetically hostile and physically compact neuroimaging environment to provide significant noise reduction, without interfering with image quality. Cancellation was first evaluated at 600 Hz, corresponding to the dominant peak in the power spectrum of the background sound and at which cancellation is maximally effective. Microphone measurements at the ear demonstrated 35 dB of acoustic attenuation [from 93 to 58 dB sound pressure level (SPL)], while masked detection thresholds improved by 20 dB (from 74 to 54 dB SPL). Considerable perceptual benefits were also obtained across other frequencies, including those corresponding to dips in the spectrum of the background sound. Cancellation also improved the statistical detection of sound-related cortical activation, especially for sounds presented at low intensities. These results confirm that ANC offers substantial benefits for fMRI research

Development of a Sampling Scheme for Pecan Weevil Damage: Causes of Nut Loss and Damage

Entomolog

Sexual signaling and immune function in the black field cricket Teleogryllus commodus

The immunocompetence handicap hypothesis predicts that male sexual trait expression should be positively correlated with immunocompetence. Here we investigate if immune function in the cricket, Teleogryllus commodus, is related to specific individual components of male sexual signals, as well as to certain multivariate combinations of these components that females most strongly prefer. Male T. commodus produce both advertisement and courtship calls prior to mating. We measured fine-scale structural parameters of both call types and also recorded nightly advertisement calling effort. We then measured two standard indices of immune function: lysozyme-like activity of the haemolymph and haemocyte counts. We found a weak, positive relationship between advertisement calling effort and lysozyme-like activity. There was, however, little evidence that individual structural call components or the net multivariate attractiveness of either call type signalled immune function. The relationships between immunity and sexual signaling did not differ between inbred and outbred males. Our data suggest that it is unlikely that females assess overall male immune function using male calls.This work was supported by the Australian Research Council (DP0555943 to M.D.J.). J.H. was funded by the Natural Environment Research Council and a Royal Society Fellowship. J.M.D. was supported by an Australian Postgraduate Award

Reprint of “Pharmacokinetic modelling of the anti-malarial drug artesunate and its active metabolite dihydroartemisinin”

A four compartment mechanistic mathematical model is developed for the pharmacokinetics of the commonly used anti-malarial drug artesunate and its principle metabolite dihydroartemisinin following oral administration of artesunate. The model is structurally unidentifiable unless additional constraints are imposed. Combinations of mechanistically derived constraints are considered to assess their effects on structural identifiability and on model fits. Certain combinations of the constraints give rise to locally or globally identifiable model structures. Initial validation of the model under various combinations of the constraints leading to identifiable model structures was performed against a dataset of artesunate and dihydroartemisinin concentration–time profiles of 19 malaria patients. When all the discussed constraints were imposed on the model, the resulting globally identifiable model structure was found to fit reasonably well to those patients with normal drug absorption profiles. However, there is wide variability in the fitted parameters and further investigation is warranted

Source-sink plasmid transfer dynamics maintain gene mobility in soil bacterial communities

Horizontal gene transfer is a fundamental process in bacterial evolution that can accelerate adaptation via the sharing of genes between lineages. Conjugative plasmids are the principal genetic elements mediating the horizontal transfer of genes, both within and between bacterial species. In some species, plasmids are unstable and likely to be lost through purifying selection, but when alternative hosts are available, interspecific plasmid transfer could counteract this and maintain access to plasmid-borne genes. To investigate the evolutionary importance of alternative hosts to plasmid population dynamics in an ecologically relevant environment, we established simple soil microcosm communities comprising two species of common soil bacteria, Pseudomonas fluorescens and Pseudomonas putida, and a mercury resistance (Hg R) plasmid, pQBR57, both with and without positive selection [i.e., addition of Hg(II)]. In single-species populations, plasmid stability varied between species: although pQBR57 survived both with and without positive selection in P. fluorescens, it was lost or replaced by nontransferable Hg R captured to the chromosome in P. putida. A simple mathematical model suggests these differences were likely due to pQBR57's lower intraspecific conjugation rate in P. putida. By contrast, in two-species communities, both models and experiments show that interspecific conjugation from P. fluorescens allowed pQBR57 to persist in P. putida via source-sink transfer dynamics. Moreover, the replacement of pQBR57 by nontransferable chromosomal Hg R in P. putida was slowed in coculture. Interspecific transfer allows plasmid survival in host species unable to sustain the plasmid in monoculture, promoting community-wide access to the plasmid-borne accessory gene pool and thus potentiating future evolvability