Impaired insulin secretion in perfused pancreases isolated from offspring of female rats fed a low protein whey-based diet.

CONTEXT: Insufficient maternal protein intake has been postulated to cause impaired fuel metabolism and diabetes mellitus in adult mammalian progeny, but the mechanism remains unclear. OBJECTIVE: To investigate the effect of a maternal low protein whey-based diet during pregnancy and lactation on pancreatic function and skeletal muscle glucose metabolism in the offspring. ANIMALS: Sprague-Dawley rats: 8 mothers and 46 offspring. DESIGN: Female rats were fed throughout pregnancy and lactation with otherwise-complete isoenergetic diets sufficient (20% whey protein; control: n=3) or insufficient (5% whey protein; low-protein: n=5) in whey protein. From weaning all offspring ate control diet. MAIN OUTCOME MEASURES: Food intake and weight gain were measured for both mothers and offspring, and in vitro functional studies of endocrine pancreas and skeletal muscle were performed on offspring at 40 and 50 days of age, respectively. RESULTS: Food intake (P=0.004) and weight gain (P=0.006) were lower in low protein than control mothers during early gestation. Offspring of low protein mothers had significant lower body weight from 5 to 15 days of age, although there was no significant difference in food consumption. Glucose, arginine- and glucose/arginine-stimulated insulin secretion from perfused pancreases isolated from low protein offspring were decreased by between 55 and 65% compared with control values. Studies in skeletal muscle demonstrated no difference in insulin sensitivity between the two groups. CONCLUSIONS: Dietary whey protein insufficiency in female rats during pregnancy and lactation can evoke major changes in insulin secretion in progeny, and these changes represent a persistent functional abnormality in the endocrine pancreas.

Induction of DNA strand breaks in the mussel (Mytilus trossulus) and clam (Protothaca staminea) following chronic field exposure to polycyclic aromatic hydrocarbons from the Exxon Valdez spill.

In 2002, 13 years after the Exxon Valdez spill, mussels and clams were examined for lingering oil exposure and damage. Known oil patches were sampled at four locations, and compared to nearby reference areas (same bay), and were also compared to "hot reference" sites to verify the methods used (Cordova harbor and fresh diesel spill at Port Chalmers). Passive samplers deployed for a month at the sites, along with tissue samples, confirmed that the oiled sites were oiled (fingerprinting back to Exxon Valdez oil) and that reference sites were clean. The highest PAH loads were detected in sub-surface interstitial waters at oiled sites. Exposure at the surface was generally low level, and probably intermittent. DNA damage was assessed in blood cells using sensitive comet analyses. DNA strand breakage was detected in both mussels and clams, with the highest level of damage detected at "hot reference" sites of Cordova harbor and Port Chalmers. Bioavailability and DNA damage at the oiled sties was low, indicating there has been substantial progress in recovery from the spill 13 years before, yet low level bioavailability and damage were still detectable.

Competitive equivalence in a community of lichens on rock.

Lichens and mosses cover 70-100% of the rock surface in a forested Appalachian boulderfield, and competition for space is intense. This paper examines overgrowth ability and its morphological correlates in four common species of foliose lichen on rocks. Overgrowth requires one lichen thallus to overtop another at the point where they meet. Therefore, I quantified margin height for a number of thalli of each of four lichen species. Two "umbilicate" species attached to the rock only at the thallus center showed a positive relationship between thallus size and margin height: large thalli often reached considerable heights above the rock surface, yet most also had points along their margin that were quite low and flat. Two other "nonumbilicate" species were characteristically flatter and showed no dependence of margin height on thallus diameter. Differences among species, among thalli of the same species, and among different points on a single thallus accounted for approximately equal amounts of variance in margin height. To determine the success of species in overtopping each other, I then recorded 639 instances of apparent overgrowth (overtopping of one thallus by another) on several rocks in the boulderfield. Of the nine pairs of species that met often enough to permit statistical analysis, only four pairs showed a consistent winner. Species in the remaining five pairs were competitively equivalent, neither winning significantly more than half the encounters although each individual encounter had a clear winner. Overgrowth rates measured from sequential photographs were highly variable, but many species pairs showed no substantial differences between growth rates over another thallus and growth rates over bare rock; only one species appeared to be affected by overgrowing other thalli. Overgrown thalli, as well as thalli experimentally shaded by gluing an overhanging rock chip above their margin for a year grew very slowly or not at all in the region of overgrowth, and the overgrown region of the thallus was often markedly discolored or disintegrating. Thus, foliose lichens compete strongly for space at the study site, yet because competitive success is at least partly based on a morphological character (margin height) that is inherently quite variable even in a single thallus, many pairs of species appear to be competitively equivalent.

Restoration of oiled mussel beds in Prince William Sound, Alaska.

Natural loss of hydrocarbons was often low from mussel (Mytilus trossulus) beds (which were typically not cleaned after the Exxon Valdez oil spill), thus this habitat remained a long-term source of oil. Consequently, experimental restoration of nine contaminated beds was attempted in 1994; mussels were removed, contaminated surface sediment was replaced (33 metric tons), and original mussels were returned. Hydrocarbon concentrations and mussel populations were monitored for 5 years thereafter. Post-restoration mussel population fluctuations were indistinguishable from regional changes. Increased short-term oil loss was apparent, but long-term (5 year) improvement was equivocal and difficult to distinguish from natural losses. By 1999, oil concentrations in mussels were typically at baseline levels in restored and oiled reference beds; concentrations in replaced sediment were elevated in one third of restored beds, indicating recontamination from underlying or surrounding sediment. Our results suggest mussel relocation is feasible but suggest oil might more effectively be removed from sediment mechanically or chemically than manually.

The first-time adult-onset offender: findings from a community corrections cohort.

Preoccupation of criminologists with juvenile-onset criminal careers overshadows the fact that offenders who begin their criminal careers in adulthood comprise a substantial portion of adult offender populations. Little is known about adult-onset offenders, generally, and even less about first-time adult-onset offenders. Using a large sample of adult felons on probation supervision, this study explores differences between first and repeat offenders. With respect to risk factors at intake, timing of rearrest, and frequency and nature of supervision failures over 3 years, first-time adult-onset participants exhibited statistically significant differences in relation to both repeat adult-onset and juvenile persistent offenders, with largest differences occurring in analyses involving the latter. With respect to risk factors at intake and rearrest, events in adulthood played a more dominant role among first-time adult-onset offenders compared with other groups, where criminal lifestyle factors were in greater evidence. The article concludes with a discussion of community supervision practices to prevent the progression of the first-time adult-onset offender's criminal career, social reforms to assist this group, and avenues for relevant future research.

Vertical distribution and probability of encountering intertidal Exxon Valdez oil on shorelines of three embayments within Prince William Sound, Alaska.

We examined 32 shorelines selected at random in 2003 from shorelines in Herring Bay, Lower Pass, and Bay of Isles in Prince William Sound, Alaska, to examine the vertical distribution of oil remaining from the 1989 Exxon Valdez oil spill and to estimate the probability that sea otters and ducks would encounter oil while foraging there. On each shoreline, sampling was stratified by 1-m tide height intervals and randomly located 0.25 m2 sampling quadrats were examined for evidence of surface and subsurface oil. Oil from the T/V Exxon Valdezwasfound on 14 shorelines, mainly in Herring Bay and Lower Pass, with an estimated 0.43 ha covered by surface oil and 1.52 ha containing subsurface oil. Surface and subsurface oil were most prevalent near the middle of the intertidal and had nearly symmetrical distributions with respect to tide height. Hence, about half the oil is in the biologically rich lower intertidal, where predators may encounter it while disturbing sediments in search of prey. The overall probability of encountering surface or subsurface oil is estimated as 0.0048, which is only slightly greaterthan our estimated probability of encountering subsurface oil in the lower intertidal of Herring Bay or Lower Pass. These encounter probabilities are sufficient to ensure that sea otters and ducks that routinely excavate sediments while foraging within the intertidal would likely encounter subsurface oil repeatedly during the course of a year.

Estimate of oil persisting on the beaches of Prince William Sound 12 years after the Exxon Valdez oil spill.

We estimated the amount of oil remaining in Prince William Sound, Alaska, 12 yr after the 1989 Exxon Valdez spill to assess its importance as a long-term reservoir of toxic hydrocarbons. We found oil on 78 of 91 beaches randomly selected according to their oiling history. Surface oiling was recorded for randomly placed quadrats, which were then excavated and examined for subsurface oil. The cumulative area of beach contaminated by surface or subsurface oil was estimated at 11.3 ha. Surface oil varied little with tide height, but subsurface oil was more prevalent at the middle tide heights. The mass of remaining subsurface oil is conservatively estimated at 55 600 kg. Analysis of terpanes indicated that over 90% of the surface oil and all of the subsurface oil was from the Exxon Valdez and that Monterey Formation oil deposited after the 1964 Alaska earthquake accounted for the remaining surface oil. These results indicate that oil from the Exxon Valdez remains by far the largest reservoir of biologically available polycyclic aromatic hydrocarbons on beaches impacted by the spill and that biota dependent on these beaches risk continued exposure.