Piping Plovers make decisions regarding dispersal based on personal and public information in a variable coastal ecosystem

ABSTRACT An increasing number of studies have revealed that public information influences dispersal decisions in a wide variety of species. However, few empirical studies have explored the effect of environmental predictability on the use of public information. We applied a model‐selection approach to data gathered from 1998 to 2006 in five eastern Canada provinces to determine the factors influencing breeding dispersal distances of Piping Plovers (Charadrius melodus melodus), a species that encounters substantial interannual changes in habitat quality. We examined the following hypotheses: (1) individuals that are unsuccessful breeders disperse greater distances than individuals that breed successfully and (2) dispersal distances of failed breeders are negatively correlated with the reproductive success of locally breeding conspecifics. We found that mean dispersal distance was greater for plovers that did not breed successfully the previous year (x′= 17.8 ± 27.4 [SD] km, N= 15) than for those that were successful (x′= 5.8 ± 26.4 km, N= 71). Failed breeders whose neighbors produced no fledged young dispersed over distances 34.8 times greater than those whose neighbors produced four fledglings. Our results show that public information is used in habitats whose environmental predictability is lower than predicted by theoretical studies. Thus, dispersal appears to be triggered by a combination of failure to hatch at least one egg, and the failure of neighboring pairs to produce fledglings. Individuals therefore appear to preferentially return to sites where breeding success is high. This may partly explain why Piping Plovers use only a fraction of the suitable breeding habitat within their geographic range. Consequently, although suitable habitat is present elsewhere within the breeding range, the loss of traditional nesting sites is likely to significantly impact productivity of this endangered species.     

Reconcentration of poliovirus from sewage.

Virus can be adsorbed from effluents of sewage treatment plants on large-surface membranes. Subsequent elution of virus requires large volumes, which in turn requires reconcentration of virus for assay. However, reconcentration of such viral eluates on small adsorbent surfaces is difficult because certain soluble sewage components are adsorbed along with the virus on the initial virus adsorbent and are removed along with the virus by the eluent. Upon acidification of the initial eluate to reconcentrate the virus on smaller membrane surfaces, flocs are formed that interfere with the reconcentration process. To circumvent this problem, the interfering sewage components can be removed by activated carbon and ion-exchange resins. The virus is then readily reconcentrated on small membranes.     

Measurement of Fronto-limbic Activity Using an Emotional Oddball Task in Children with Familial High Risk for Schizophrenia

Adolescence is a critical developmental period where the early symptoms of schizophrenia frequently emerge. First-degree relatives of people with schizophrenia who are at familial high risk (FHR) may show similar cognitive and emotional changes. However, the neurological changes underlying the emergence of these symptoms remain unclear. This study sought to identify differences in frontal, striatal, and limbic regions in children and adolescents with FHR using functional magnetic resonance imaging. Groups of 21 children and adolescents at FHR and 21 healthy controls completed an emotional oddball task that relied on selective attention and the suppression of task-irrelevant emotional information. The standard oddball task was modified to include aversive and neutral distractors in order to examine potential group differences in both emotional and executive processing. This task was designed specifically to allow for children and adolescents to complete by keeping the difficulty and emotional image content age-appropriate. Furthermore, we demonstrate a technique for suitable fMRI registration for children and adolescent participants. This paradigm may also be applied in future studies to measure changes in neural activity in other populations with hypothesized developmental changes in executive and emotional processing.     

Effect of NSAIDs and Diuretics on Nephrogenesis in an Ex Vivo Embryogenic Kidney Model

The kidney is one of the key organs in clearing foreign compounds. The effects of drugs on the developing kidney are relatively unknown. We studied the direct effect of furosemide, hydrochlorothiazide, ibuprofen, and indomethacin on kidney development in an ex vivo embryonic kidney model. At embryonic day 13, metanephroi were dissected from mice and cultured in control media or media supplemented with various clinically relevant concentrations of drugs. The ureteric tree was visualized by whole‐mount staining and branching was evaluated by counting. Additionally, gene expression levels of Wt1, Sox9, Bmp7, Fgf8, and Gdnf were investigated. No distinct differences were noted on either ureteric tip development or gene expression analysis for each drug after 24 hr of exposure. Even though short‐term exposure to clinically relevant concentrations seems not to disturb renal development, future research is needed to study prolonged or repeated exposures.