Effects Of Tropical Storm Agnes On Zooplankton In The Lower Chesapeake Bay

Sampling techniques in use since August 1971 were employed to study effects of Tropical Storm Agnes on lower Chesapeake Bay zooplankton following the storm\u27s passage on June 21, 1972. Mean catches of copepods, cladocerans, barnacle larvae, decapod larvae, chaetognaths, and fish eggs and larvae were calculated for the entire study area and six subareas from 8 bongo net collections. A single subarea was selected for specific identifications within major taxa of zooplankton.https://scholarworks.wm.edu/vimsbooks/1072/thumbnail.jp

Alcohol-induced apoptosis of oligodendrocytes in the fetal macaque brain

BACKGROUND: In utero exposure of the fetal non-human primate (NHP) brain to alcohol on a single occasion during early or late third-trimester gestation triggers widespread acute apoptotic death of cells in both gray and white matter (WM) regions of the fetal brain. In a prior publication, we documented that the dying gray matter cells are neurons, and described the regional distribution and magnitude of this cell death response. Here, we present new findings regarding the magnitude, identity and maturational status of the dying WM cells in these alcohol-exposed fetal NHP brains. RESULTS: Our findings document that the dying WM cells belong to the oligodendrocyte (OL) lineage. OLs become vulnerable when they are just beginning to generate myelin basic protein in preparation for myelinating axons, and they remain vulnerable throughout later stages of myelination. We found no evidence linking astrocytes, microglia or OL progenitors to this WM cell death response. The mean density (profiles per mm(3)) of dying WM cells in alcohol-exposed brains was 12.7 times higher than the mean density of WM cells dying by natural apoptosis in drug-naive control brains. CONCLUSIONS: In utero exposure of the fetal NHP brain to alcohol on a single occasion triggers widespread acute apoptotic death of neurons (previous study) and of OLs (present study) throughout WM regions of the developing brain. The rate of OL apoptosis in alcohol-exposed brains was 12.7 times higher than the natural OL apoptosis rate. OLs become sensitive to the apoptogenic action of alcohol when they are just beginning to generate constituents of myelin in their cytoplasm, and they remain vulnerable throughout later stages of myelination. There is growing evidence for a similar apoptotic response of both neurons and OLs following exposure of the developing brain to anesthetic and anticonvulsant drugs. Collectively, this body of evidence raises important questions regarding the role that neuro and oligo apoptosis may play in the human condition known as fetal alcohol spectrum disorder (FASD), and also poses a question whether other apoptogenic drugs, although long considered safe for pediatric/obstetric use, may have the potential to cause iatrogenic FASD-like developmental disability syndromes

Nest site selection and nest survival of Greater Prairie-Chickens near a wind energy facility

Rapid development of wind energy facilities in the Great Plains of North America has raised concerns regarding their potential negative impact on the nesting ecology of Greater Prairie-Chickens (Tympanuchus cupido pinnatus). We investigated the effects of a pre-existing, 36-turbine wind energy facility on nest site selection and nest survival of Greater Prairie-Chickens in the unfragmented grasslands of the Nebraska Sandhills, USA. In 2013 and 2014, we monitored 91 nests along a 24-km disturbance gradient leading away from the wind energy facility. We found little evidence of an effect of the wind energy facility on Greater Prairie-Chicken nest site selection and nest survival. Instead, we found that the primary drivers of nest site selection and nest survival were related to landscape and habitat factors. Greater Prairie-Chickens avoided nesting near roads, with 74% of Greater Prairie-Chickens selecting nest sites .700 m from roads. Greater Prairie-Chickens selected nest sites with more than twice the visual obstruction and residual standing dead vegetation of random points. Our results suggest that small wind energy facilities, such as the facility in our study, may have little effect on Greater Prairie-Chicken nest site selection and nest survival. We suggest that livestock grazing and other grassland management practices still have the most important regional effects on Great Prairie-Chickens, but we caution future planners of wind energy facilities to account for the potential negative effect of roads on nest site selection. El ra´pido desarrollo de los parque de energ´ıa e´ olica en las Grandes Llanuras de Am´ erica del Norte ha generado preocupaci ´on sobre su potencial impacto negativo en la ecolog´ıa de anidaci ´on de Tympanuchus cupido pinnatus. Investigamos el efecto de un parque de energ´ıa preexistente de 36 turbinas e´ olicas sobre la selecci ´on del sitio de anidaci ´on y la supervivencia del nido de T. c. pinnatus en los pastizales no fragmentados de las Sandhills de Nebraska. En 2013 y 2014, monitoreamos 91 nidos a lo largo de un gradiente de disturbio de 24 km que se alejaba del parque de energ´ıa e´ olica. Encontramos poca evidencia de un efecto del parque de energ´ıa e´ olica sobre la selecci ´on del sitio de anidaci ´on y la supervivencia del nido en T. c. pinnatus. En cambio, encontramos que las causas principales de la selecci ´on del sitio de anidaci ´on y la supervivencia del nido se relacionaron con el paisaje y los factores del ha´bitat. La especie T. c. pinnatus evit ´o anidar cerca de las rutas, con un 74% de los individuos seleccionando sitios de anidaci ´on .700 m desde las rutas. Los individuos seleccionaron sitios de anidaci ´on con ma´s del doble de obstrucci ´on visual y vegetaci ´on residual muerta en pie con relaci ´on a puntos elegidos al azar. Nuestros resultados sugieren que peque˜ nos parques e ´ olicos, como el de nuestro estudio, tendr´ıan un efecto menor en la selecci ´on del sitio de anidaci ´on y en la supervivencia del nido en T. c. pinnatus. Sugerimos que el pastoreo del ganado y otras pra´cticas de manejo de los pastizales se mantienen como los impactos regionales ma´s importantes para T. c. pinnatus, pero alertamos a los futuros gestores de los parques de energ´ıa e´ olica para que contemplen los potenciales efectos negativos de las rutas en la selecci ´on del sitio de anidaci ´ on

Makerspaces in early childhood education : principles of pedagogy and practice

The aim of the study reported in this paper was to identify the value that makerspaces can have in early childhood education (ECE). Drawing on data from research on makerspaces in four early childhood settings in a northern city in England, part of an international project on makerspaces in the early years (“Makerspaces in the Early Years: Enhancing Digital Literacy and Creativity” or MakEY), we identify three key principles that are integral to this provision: maker agency, maker funds of knowledge, and postdigital maker play. The paper identifies that makerspaces lead to the development of skills and knowledge that will become increasingly important in societies that are becoming highly technologized

Evaluating the Current Status of American Shad Stocks in Three Virginia Rivers

Directed commercial fisheries for American shad Alosa sapidissima in the primary Virginia tributaries of the Chesapeake Bay have been under moratorium since 1994. Monitoring of adult American shad within these rivers has been ongoing since 1998 through a cooperative program involving commercial fishers. The monitoring program is designed to mimic traditional commercial fishing practices so that stock status can be inferred by comparing contemporary catch-per-unit-effort levels with those derived from historic logbooks. In this paper, we present analyses of the available monitoring and historic catch rate data along with updated stock status information for American shad in the James, York, and Rappahannock rivers. Two analytical methods were used to derive annual indices of relative abundance; both methods yielded very similar patterns for each river system. Comparisons of contemporary and historic indices of relative abundance suggest that American shad in the James and York rivers continue to persist at low levels of abundance. Measures of stock abundance in the Rappahannock River have been higher than the logbook reference value for much of the monitoring period. However, current moratoria and restoration strategies, which include hatchery releases of fry, the removal of obstructions blocking spawning and nursery habitat, and reductions in bycatch from other fisheries, should continue into the foreseeable future