Shellfish Spotlight: 2008

Each year Granite State shellfishers search shallow briny waters in search of delicious mussels, clams, or oysters for the dinner table. Those who are skilled often are rewarded with full buckets, but few shellfishers realize that good harvests in New Hampshire’s Seacoast owe much to activities occurring far upstream. The quality of the water and amount of available nutrients that sustain a clam or oyster is directly related to the condition of the rivers and streams that drain the land. The Hampton-Seabrook Estuary is fed by approximately 46 square miles of surrounding land. An even larger system, the Piscataqua River Estuary that includes Great Bay, is supplied by a watershed that is 1,023 square miles. Development within the coastal watershed area has profound impacts on the amount of contaminants flowing to the sea. Sediment washed from roadways and bare soil flows downstream and collects in the estuary where it smothers shellfish beds in extreme cases. Nutrients, primarily nitrogen, are contributed by wastewater treatment plants, septic systems, and land use activities such as lawn fertilizing. Excessive nutrients threaten the ecological balance of the estuaries and thus the survival of shellfish populations. Finally, bacteria from failing septic systems, pet waste, or damaged sewer systems create a human health hazard in estuarine waters. Because shellfish filter great amounts of water to take in food and oxygen, they absorb contaminants from the water that accumulate in their flesh. Therefore, a watershed that flushes large amounts of contaminants downstream will deliver many of these contaminants to shellfish and reduce their numbers or often make them unsafe to eat. It is this close relationship between coastal watershed function and shellfish health that caused the New Hampshire Estuaries Project (NHEP), and many partnering agencies, to monitor shellfish in New Hampshire and make their restoration and maintenance a priority. The NHEP Manage- ment Plan includes many strategies that improve water quality throughout the watershed that will in turn improve shellfish populations and open more harvesting areas

Survey of Terrestrial Invertebrate Species from Byers Cave; Dade County, Georgia

Byers Cave is one of Georgia’s largest cave systems and is inhabited by a wide variety of unique invertebrate organisms that have not been documented or studied. From March 2008 through April 2010, baited ramp pit-fall traps and visual surveys were used to sample and document invertebrate species that live in this cave system. After three trapping periods and four visual surveys, we collected over 4,400 individuals comprising 13 orders, 29 families and 34 species. The majority of these species were troglophiles and trogloxenes; however, there were also numerous troglobitic species present

Functional Brain Signals: A photon counting system for brain activity monitoring

A simplified in vivo near infrared spectroscopy (NIRS) system for functional brain analysis and a protocol for the study of visual evoked potentials in the human brain is presented. A novel NIRS system bases on a simple photon counting technique using a CW light source (laser diode at 780 nm), fibre optodes delivering light to the subject and from the subject to detector, a photomultiplier tube (PMT) for high infra-red (IR) response and the 800 MHz Gated Photon Counter/multichannel scaler (MCS) for data acquisition. A chequerboard stimulus was used to elicit a response signal from the visual cortex. This photon signal arising from the cortical systems of the brain was processed to detect features indicative of the neural processing systems involved

Functional Brain Signals: A photon counting system for brain activity monitoring

A simplified in vivo near infrared spectroscopy (NIRS) system for functional brain analysis and a protocol for the study of visual evoked potentials in the human brain is presented. A novel NIRS system bases on a simple photon counting technique using a CW light source (laser diode at 780 nm), fibre optodes delivering light to the subject and from the subject to detector, a photomultiplier tube (PMT) for high infra-red (IR) response and the 800 MHz Gated Photon Counter/multichannel scaler (MCS) for data acquisition. A chequerboard stimulus was used to elicit a response signal from the visual cortex. This photon signal arising from the cortical systems of the brain was processed to detect features indicative of the neural processing systems involved

A disk census for the nearest group of young stars: Mid-infrared observations of the TW Hydrae Association

A group of young, active stars in the vicinity of TW Hydrae has recently been identified as a possible physical association with a common origin. Given its proximity ($\sim$50 pc), age ($\sim$10 Myr) and abundance of binary systems, the TW Hya Association is ideally suited to studies of diversity and evolution of circumstellar disks. Here we present mid-infrared observations of 15 candidate members of the group, 11 of which have no previous flux measurements at wavelengths longer than 2$\mu$m. We report the discovery of a possible 10$\mu$m excess in CD -33$^{\circ}$7795, which may be due to a circumstellar disk or a faint, as yet undetected binary companion. Of the other stars, only TW Hya, HD 98800, Hen 3-600A, and HR 4796A -- all of which were detected by IRAS -- show excess thermal emission. Our 10$\mu$m flux measurements for the remaining members of the Association are consistent with photospheric emission, allowing us to rule out dusty inner disks. In light of these findings, we discuss the origin and age of the TW Hya Association as well as implications for disk evolution timescales.Comment: 10 pages and 1 PostScript figure, accepted for publication in The Astrophysical Journal Letter

State of the art: noninvasive imaging and management of neurovascular trauma

Neurotrauma represents a significant public health problem, accounting for a significant proportion of the morbidity and mortality associated with all traumatic injuries. Both blunt and penetrating injuries to cervicocerebral vessels are significant and are likely more common than previously recognized. Imaging of such injuries is an important component in the evaluation of individuals presenting with such potential injuries, made all the more important since many of the vascular injuries are clinically silent. Management of injuries, particularly those caused by blunt trauma, is constantly evolving. This article addresses the current state of imaging and treatment of such injuries