Models and mechanisms of regenerative biology across phylogeny : introduction to a virtual symposium in The Biological Bulletin

Author Posting. © Marine Biological Laboratory, 2011. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 221 (2011): 3-5.This virtual symposium issue of The Biological Bulletin celebrates a major milestone for our publisher, The Marine Biological Laboratory, as it opens the new Eugene Bell Center for Regenerative Biology and Tissue Engineering on its Woods Hole campus. As with recent virtual symposia published by the journal, the current issue brings together a set of invited reviews, original research reports, and a position paper that offers a coherent and current window into some of the major contemporary trends in animal regeneration research

Transmission loss in manatee habitats

The Florida manatee is regularly exposed to high volumes of vessel traffic and other human-related noise because of its coastal distribution. Quantifying specific aspects of the manatee’s acoustic environment will allow for a better understanding of how these animals respond to both natural and human-induced changes in their environment. Transmission loss measurements were made in 24 sampling sites that were chosen based on the frequency of manatee presence. The Monterey-Miami Parabolic Equation model was used to relate environmental parameters to transmission loss in two extremely shallow water environments: seagrass beds and dredged habitats. Model accuracy was verified by field tests at all modeled sites. Results indicated that high-use grassbeds have higher levels of transmission loss for frequencies above 2 kHz compared to low-use sites of equal food species composition and density. This also happens to be the range of most efficient sound propagation inside the grassbed habitat and includes the dominant frequencies of manatee vocalizations. The acoustic environment may play a more important role in manatee grassbed selection than seagrass coverage or species composition, as linear regression analysis showed no significant correlation between usage and either total grass coverage, individual species coverage, or aerial pattern

Effects of anxiety-relieving drugs on unit discharges in hippocampus, reticular midbrain, and pre-optic area in the freely moving rat

The effects on unit discharges of various doses of the compounds chlordiazepoxide, meprobamate, sodium pentobarbital, and diazepam were studied in the unanesthetized, unrestrained rat. Recordings of action potentials were made simultaneously in hippocampus, pre-optic region, and the reticular formation of the midbrain. The doses of chlordiazepoxide were 5, 10, 20 and 40 mg/kg; 5, 10 and 20 mg/kg of sodium pentobarbital; 80, 100 and 120 mg/kg of meprobamate, and finally 5, 10 and 20 mg/kg of diazepam.In the hippocampus, chlordiazepoxide depressed spontaneous activity at every dose used. The reduction ranged from 30 to 50%, but in no case was there inhibition of all discharges. Diazepam also had substantial depressing effects on the activity in this region of the brain. In contrast, sodium pentobarbital had relatively minor effects in the lower dose range, but significant depressing effects at the higher doses. Meprobamate also had comparatively small effects in the hippocampus.In the pre-optic area, chlordiazepoxide and meprobamate depressed spontaneous activity at the higher dose range. There were small effects in the lower dose range. Sodium pentobarbital also had minor depressing effects at all doses. Diazepam caused less depression even at the higher doses than either chlordiazepoxide or meprobamate, and these effects were transient.In the midbrain reticular formation, meprobamate caused substantial depression of spontaneous activity even at the lower doses. Sodium pentobarbital similarly depressed activity, but the onset of effect was less delayed than with meprobamate. Chlordiazepoxide at low doses caused less depression of reticular midbrain neurons than of hippocampal or pre-optic region ones. At high doses, the effect was similar to that of meprobamate.The data suggest the possibility of a mode of action of chlordiazepoxide and diazepam which implicates the hippocampus, whereas in the case of sodium pentobarbital and meprobamate, the mode of action appears to implicate the midbrain reticular area. Such a view is based upon comparison of effects at low doses on spontaneous activity of the three regions investigated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33003/1/0000387.pd

Physical activity and screen time behaviour in metropolitan, regional and rural adolescents: A cross-sectional study of Australians aged 9–16 years

Objectives: While there is consistent evidence that rural adults in Australia are less active than their urban counterparts, studies relating geographical remoteness to activity patterns in Australian adolescents have yielded inconsistent results. The aim of this study was to describe objectively and subjectively measured patterns of physical activity and sedentary behaviours across remoteness categories in a representative sample of 9–16 year old Australians. Design: Cross-sectional observational study. Methods: 2071 Australian adolescents provided self-report use of time data on four days and wore a pedometer for at least 6 days within the 2007 Australian National Children’s Nutrition and Physical Activity Survey. Comparisons of activity patterns were made across four objectively-determined remoteness categories (Major City, Inner Regional, Outer Regional and Remote), adjusting for household income, parental education and age. Results: Adolescents living in major cities self-reported 11–29 min less moderate to vigorous physical activity each day than their counterparts living in geographically more remote areas, and took 150–850 fewer steps each day. While there were no differences in time spent in sport or active transport, differences in free play participation were significant. Males in major cities also reported higher levels of screen time. Differences were somewhat more marked among males than among females. Conclusions: Activity levels among Australian adolescents show contrasting patterns of geographical differences to those found in Australian adults. Higher levels of free play among rural Australian adolescents may be due to more available space and less fear of traffic and stranger risks

Health visiting - the end of a UK wide service?

In 1997 Health Visiting was deemed by New Labour to be an important player in reducing health inequalities. It was acknowledged that if Health Visiting was to fulfill this vision it would have to work out with its traditional child health role and also engage with groups, communities and populations to tackle the determinants of ill health. Twelve years on, external factors such as, NHS cut backs, recent changes to how Health Visitors are regulated throughout the UK and devolved Health Visiting policy making structures have led to the rapid demise in status and legitimacy of Health Visiting and its wider public health role. This article argues that the unintended consequences of devolved Health Visiting policy has resulted in 3 recent community nursing and health-visiting reviews in Scotland and England which have made divergent policy recommendations about the role of the Health Visitor in tackling health inequalities. The recommendations outlined in the Scottish review in particular threatened to jeopardise the very future provision of a UK wide Health Visiting service. If Health Visiting is to survive as a UK wide entity, a radical independent rethink as to its future direction and its public health role is urgently required

A motivational analyses of the reticular activating system

In 51 rats electrode pairs were chronically implanted with spacing 1 mm. apart from rat to rat to make a grid of the tegmentum. In each case three tests were made: a self-stimulation test for positive reinforcement; an escape test for negative reinforcement; and an EEG test for cortical arousal. The main results were these: all points yielding escape at very low thresholds were clustered in the dorso-medial tegmentum just below the tectum and just lateral to the central grey; all points yielding self-stimulation at high rates were clustered ventrally, usually below and lateral to the medial lemniscus; and points yielding arousal at very low thresholds were clustered in the lateral tegmentum, half-way up from the ventral surface.As for interactions between the three effects, all points yielding escape at low thresholds also yield arousal at low thresholds; al points yielding self-stimulation at high rates yielded arousal at moderately high thresholds; and some points yielded both moderate escape and moderate self-stimulation. Finally, there definitely were points which yielded arousal at low thresholds and which yielded no other motivational effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32417/1/0000496.pd

Note and Comment

Termination of the Liability as Common Carrier; Is a Vendee Seeking Specific Performance Entitled to Compensation for the Inchoate Dower Right of the Vendor\u27s Wife?; An Executor\u27s Right to an Allowance out of the Estate for Counsel Fees for Services Rendered Before Letters Testamentary Issue; The Kansas Manhattan Cocktail Case and Some Others Concerning Judicial Notice

Reinforcing brain stimulation and memory in monkeys

Sixty electrodes were implanted in various structures in the brain of two cynomologous monkeys subsequently trained to perform a three-position delayed response task. Each brain point was tested for the effects of electric stimulation, applied during the retention interval, on delayed response performance and for appetitive and aversive effects. At all points where there was clear evidence of approach or avoidance with respect to the brain stimulus, there was definite impairment of delayed response performance. In six of the twenty cases where there was possible evidence of approach or avoidance, there was impairment of delayed response. In none of the twenty-six cases where there was no evidence of approach or avoidance was there any evidence of impairment. The data were interpreted as indicating that the impairment produced by brain shocks could be accounted for by their appetitive or aversive effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32081/1/0000130.pd