Predator- and Scavenger-Mediated Ecosystem Services Determined by Distance to Field-Forest Interface in the Maine Lowbush Blueberry Agroecosystem

Predators and scavengers play a vital role in regulating insect pests, weeds, and vertebrate scat in perennial agroecosystems. Understanding how farm management practices and surrounding habitat influence these beneficial ecosystem services contributes to our understanding of these complex ecological systems and guides future management decisions. In a mensurative 2-yr study, we determined how different pest management strategies and surrounding forest composition influenced levels of sentinel insect pupae, weed seeds, and deer scat (feces) removal. Removal of these bioresources was measured within 12 commercial lowbush blueberry fields during 2011 and 2012; farms differed in surrounding landscape composition and farm management strategies. Both the removal of sentinel pupae and scat, was significantly higher within field interiors than at field edges and within adjacent forests. Additionally, farm management strategy interacted with field position to result in significantly higher scat removal in conventional field interiors than organic field interiors. Surrounding forest composition had variable effects on removal of materials. Our results indicate higher levels of activity within field centers as opposed to field edges; this is contrary to what has been observed in other perennial cropping agroecosystems.

Evaluating Utility Gloves as a Potential Reservoir for Pathogenic Bacteria

PURPOSE

This pilot study sought to determine the rate and degree to which gram-negative Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa and gram-positive Staphylococcus aureus occurred on the inside of utility gloves used at University of Maine at Augusta, Dental Health Programs' dental hygiene clinic.

METHODS

Five steam autoclave utility gloves were randomly selected to serve as control and a convenience sample of 10 used utility gloves were selected from the sterilization area. A sample was collected from a predetermined surface area from the inside of each steam autoclave utility glove and used utility glove. Each sample was used to inoculate a Petri plate containing 2 types of culture media. Samples were incubated at 37° C for 30 to 36 hours in aerobic conditions. Colony forming units (CFU) were counted.

RESULTS

Confidence intervals (CI) estimated the rate of contamination with gram-negative K. pneumoniae, E. coli and P. aeruginosa on the inside of steam autoclave utility gloves to be n=33 95% CL [0.000, 0.049], used utility gloves to be n=70, 95% CL [0.000, 0.0303]. Data estimated the rate of contamination with gram-positive S. aureus on the inside of steam autoclave utility gloves to be n=35, 95% CL [0.233, 0.530], used utility gloves to be n=70, 95% CL [0.2730, 0.4975]. Culture media expressed a wide range of CFU from 0 to over 200.

CONCLUSION

The risk of utility glove contamination with gram-negative bacteria is likely low. The expressed growth of S. aureus from steam autoclave utility gloves controls raises questions about the effectiveness and safety of generally accepted sterilization standards for the governmentally mandated use of utility gloves.

Investigating the mechanism for maintaining eucalcemia despite immobility and anuria in the hibernating American black bear (Ursus americanus)

Ursine hibernation uniquely combines prolonged skeletal unloading, anuria, pregnancy, lactation, protein recycling, and lipolysis. This study presents a radiographic and biochemical picture of bone metabolism in free-ranging, female American black bears (Ursus americanus) that were active (spring bears and autumn bears) or hibernating (hibernating bears). Hibernating bears included lactating and non-lactating individuals. We measured serum calcium, albumin, inorganic phosphate, creatinine, bone specific alkaline phosphatase (BSALP), CTX, parathyroid hormone, insulin-like growth factor-I (IGF-l), leptin, 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and sclerostin from 35 to 50 tranquilized hibernating bears and 14 to 35 tranquilized spring bears. We compared metacarpal cortical indices (MCI), measured by digital X-ray radiogrammetry, from 60 hunter-killed autumn bears and 79 tranquilized, hibernating bears. MCI was greater in autumn than winter in younger bears, but showed no seasonal difference in older bears. During hibernation eucalcemia was maintained, BSALP was suppressed, and CTX was in the range expected for anuria. During hibernation 1,25(OH)(2)D was produced despite anuria. 1,25(OH)(2)D and IGF-I were less in hibernating than spring bears. In a quarter of hibernating bears, sclerostin was elevated. Leptin was greater in hibernating than spring bears. In hibernating bears, leptin correlated positively with BSALP in non-lactating bears and with CTX in lactating bears. Taken together the biochemical and radiographic findings indicate that during hibernation, bone turnover was persistent, balanced, and suppressed; bone resorption was lower than expected for an unloaded skeleton; and there was no unloading-induced bone loss. The skeleton appears to perceive that it was loaded when it was actually unloaded during hibernation. However, at the level of sclerostin, the skeleton recognized that it was unloaded. During hibernation leptin appeared anabolic in non-lactating bears and catabolic in lactating bears. We hypothesize that ursine hibernation may represent a natural model in which suppression of the sympathetic nervous system prevents unloading-induced bone loss by influencing leptin's skeletal effects and preventing transmission of loading information.

Use of primer selection and restriction enzymes to assess bacterial community diversity in an agricultural soil used for potato production via terminal restriction fragment length polymorphism

Terminal restriction fragment length polymorphism (T-RFLP) can be used to assess how land use management changes the dominant members of bacterial communities. We compared T-RFLP profiles obtained via amplification with forward primers (27, 63F) each coupled with the fluorescently labeled reverse primer (1392R) and multiple restriction enzymes to determine the best combination for interrogating soil bacterial populations in an agricultural soil used for potato production. Both primer pairs provide nearly universal recognition of a 1,400-bp sequence of the bacterial domain in the V(1)-V(3) region of the 16S ribosomal RNA (rRNA) gene relative to known sequences. Labeling the reverse primer allowed for direct comparison of each forward primer and the terminal restriction fragments' relative migration units obtained with each primer pair and restriction enzyme. Redundancy analysis (RDA) and nested multivariate analysis of variance (MANOVA) were used to assess the effects of primer pair and choice of restriction enzyme on the measured relative migration units. Our research indicates that the 63F-1392R amplimer pair provides a more complete description with respect to the bacterial communities present in this potato (Solanum tuberosum L.)-barley (Hordeum vulgare L.) rotation over seeded to crimson clover (Trifolium praense L.). Domain-specific 16S rRNA gene primers are rigorously tested to determine their ability to amplify across a target region of the gene. Yet, variability within or between T-RFLP profiles can result from factors independent of the primer pair. Therefore, researchers should use RDA and MANOVA analyses to evaluate the effects that additional laboratory and environmental variables have on bacterial diversity.

Mercury in tree swallow food, eggs, bodies, and feathers at Acadia National Park, Maine, and an EPA superfund site, Ayer, Massachusetts

We monitored nest boxes during 1997-1999 at Acadia National Park, Mt. Desert Island, ME and at an old-field site in Orono, ME to determine mercury (Hg) uptake in tree swallow (Tachycineta bicolor) eggs, tissues, and food boluses. Also, in 1998-1999 we monitored nest boxes at Grove Pond and Plow Shop Pond at a U.S. Environmental Protection Agency Superfund site in Ayer, MA. We recorded breeding success at all locations. On average among locations, total mercury (THg) biomagnified 2 to 4-fold from food to eggs and 9 to 18-fold from food to feathers. These are minimum values because the proportion of transferable methyl mercury (MeHg) of the THg in insects varies (i.e., 35%-95% of THg) in food boluses. THg was highest in food boluses at Aunt Betty Pond at Acadia, whereas THg in eggs was highest at the Superfund site. A few eggs from nests at each of these locations exceeded the threshold (i.e., 800-1,000 ng/g, wet wt.) of embryotoxicity established for Hg. Hatching success was 88.9% to 100% among locations, but five eggs failed to hatch from 4 of the 11 clutches in which an egg exceeded this threshold. MeHg in feathers was highest in tree swallows at Aunt Betty Pond and the concentration of THg in bodies was related to the concentration in feathers. Transfer of an average of 80%-92% of the Hg in bodies to feathers may have enhanced nestling survival. Residues of Hg in tissues of tree swallows in the Northeast seem higher than those of the Midwest.

Listeria monocytogenes in an Atlantic salmon (Salmo salar) processing environment

The behavior of two strains of Listeria monocytogenes (147 and ATCC 19111) was evaluated at different stages of salmon processing. At lower temperatures of 2, 7, and 11 degrees C, L. monocytogenes survived on dry wood surfaces for at least 3 days without added nutrients but was unrecoverable after 2 days at 22 degrees C. Moisture or minimal nutrients on the wood surface increased viability of L. monocytogenes at all incubation temperatures. When large amounts of nutrients were provided, the recoveries of L. monocytogenes at low temperatures (< or = 11 degrees C) were essentially unchanged over the 3-day holding period, and rapid growth was observed at room temperature. In the presence of natural microflora, L. monocytogenes died off rapidly in seawater within 36 h at room temperature. When held at < or = 11 degrees C, L. monocytogenes lost viability throughout storage but was still detectable after more than 6 days of incubation. In the absence of natural microflora, both strains of L. monocytogenes were static during the holding period at all temperatures. At 2, 7, and 11 degrees C, L. monocytogenes in nonsterile salmon blood-water remained viable even after 6 days of incubation, whereas in sterile blood-water, growth of L. monocytogenes was observed at 7 and 11 degrees C. In the absence of natural microflora, L. monocytogenes grew better than it did in the presence of natural microflora. L. monocytogenes 147 was more competitive with background organisms than was L. monocytogenes ATCC 19111. No L. monocytogenes could be detected in the digestive tract of salmon 3 days after its introduction. The survival pattern of L. monocytogenes in fish digestive tracts was similar, regardless of whether the fish were feeding or not. A noticeable decline in the pathogen was observed as early as 3 h after introduction.

Adolescent Girls in Maine Are at Risk for Vitamin D Insufficiency

The objective was to determine the seasonal fluctuations in serum 25-hydroxyvitamin D (25-OHD) in a group of healthy adolescents living in a northern climate. Twenty-three 9- to 11-year-old girls participated in the study from September 2000 to March 2003. Serum 25-OHD and parathyroid hormone levels were measured each September and March. Dietary intake of vitamin D was assessed each summer and winter. Summer-sun exposure was evaluated using reports of time spent outdoors. The mean decrease in serum 25-OHD from September to March was 28%. Vitamin D insufficiency (at least one serum 25-OHD level <50 nmol/L) was observed in 11 of 23 (48%) subjects. Four of 23 subjects (17%) exhibited vitamin D insufficiency in both September and March. Mean parathyroid hormone levels increased 4 pg/mL (15%) from September to March. Vitamin D intakes need to be increased in winter at northern latitudes.

Athletes and rape: is there a connection?

The present study builds upon previous research examining variables related to sexual assault. Previous studies have linked sexual aggression with attitudes toward rape as well as hostility toward women. Recent high-profile cases involving athletes and sexual assault have raised questions about the link with athletes. In fact, recent research has suggested that athletes may be more prone to commit rape; however, no study has examined competitiveness. This characteristic, associated with athletes, may predict sexual aggression and help assess why rape is reportedly perpetrated by athletes significantly more frequently than by nonathletes. It may be that individuals with high competitiveness may be more likely to be involved in sexual assaults. Scores on Competitiveness in 104 college men were significantly correlated with reported sexual aggression and athletic participation; however, there was no significant difference between athletes and nonathletes on aggressive sexual behavior. These findings suggest that characteristics of athletes rather than athletic participation alone must be considered further in examining the presumed link between athletes and sexual assault.

Morphological variation in sexual and agamospermous Amelanchier (Rosaceae)

Agamospermy, which is almost always associated with polyploidy, is often assumed to reduce variation and foster evolution of microspecies. We tested for the occurrence of microspecies by comparing variation of sexual Amelanchier bartramiana and facultatively agamospermous (asexually seed-producing) Amelanchier laevis. We assessed within- and among-population variation of 222 individuals from six Maine populations of each species for eight morphological variables. Mahalanobis distances between individuals and population centroids and between population centroids and species centroids were used as measures of within- and among-population variation, respectively. Amelanchier bartramiana contains significantly more within- and among-population morphological variation than A. laevis. The two species do not differ in how they partition morphological variation within and among populations. Amelanchier laevis thus does not contain microspecies. Variation within A. laevis may be the result of sexuality, hybridization, polyploidy, and other factors. Key words: Amelanchier, agamospermy, Levene's statistic, microspecies, variation.

Canopy dynamics and the morphological development of Abies balsamea: effects of foliage age on specific leaf area and secondary vascular development

Data were collected from two branches from each whorl of nine open-grown Abies balsamea (L.) Miller trees to test the hypothesis that specific leaf area (SLA, m(2) projected fresh leaf area kg(-1) oven-dry foliage) is constant among five foliage age classes (current-year, 1-year-old, 2-year-old, 3-year-old and 4-year-old-plus). Between-tree variation in SLA was greater than within-tree variation. Differences in SLA among the foliage age classes were small, but statistically significant, showing a trend of decreasing SLA with increasing foliage age. Using data from two previous biomass studies, we found that three different methods of calculating SLA of individual trees produced the same projected leaf area estimates. To test the hypothesis that foliage mass increases with foliage age as a result of secondary xylem or phloem development, we examined the secondary vascular development of foliage collected from five age classes and three crown sections in an open-grown A. balsamea. The number of rows of xylem cells was not constant among foliage age classes, but the differences were small and showed no consistent pattern of change with foliage age. Total number of rows of phloem cells increased, number of living rows of phloem cells decreased, and the number of rows of nonliving crushed phloem cells increased with foliage age.

A Simple Procedure to Monitor Fecal Coliforms in Seafood Processing Plants

Various seafoods were inoculated with six different strains of Escherichia coli at two concentrations (about 10 and 100 cells/g). The samples were then either homogenized or massaged in buffer using sterile sample bags. E. coli concentration was estimated using the standard procedure (MPN) or microbiological test kits, Petrifilm-VRB and Redigel-VRB, incubated at 45.5°C. The correlation (r) between counts generated using the standard procedure and those from massaged samples, using any of the media employed, was slightly higher than 0.60. Despite the low correlations among procedures, massaging and inoculating microbiological test kits will detect accidental fecal contamination (>600 cells/100 g), but can be modified to detect contamination ≤230 cells/100 g. Probabilities involved in estimated fecal coliform concentration, when few colonies are observed, are discussed.

Effects of early maturation of brown egg-type pullets, flock uniformity, layer protein level, and cage design on egg production, egg size, and egg quality

Eight-week-old Harco Sex-Link pullets were assigned to four growing regimens. Feed was restricted to Group 1. The birds reached an average weight of 1.52 kg at 20 weeks of age and were then light stimulated. Group 2 received the same ration ad lib and reached an average weight of 1.64 kg at 16 weeks. At this age they were light stimulated. Birds in Groups 3 and 4 were separated into two weight classes at 8 weeks of age. Those below the median weight received an 18% protein grower ration and those above the median weight a 16% ration. Group 3 birds were grown similarly to Group 1; Group 4 birds were grown similarly to Group 2. At housing, each group was equally divided and given either a 17 or 19% protein layer ration. Two cage designs (standard and reverse) were used and each treatment combination was equally represented. Ad lib-fed, early-housed pullets reached 1.64 kg at 16 weeks of age, but they did not come into production until 19.4 weeks of age. Hen-day percent production (HDP) was significantly less than for the late-housed pullets. Feed per dozen eggs was not affected by the early housing, but early-housed pullets laid significantly smaller eggs and feed per gram egg was significantly increased. Hens in reverse cages on a 19% protein layer ration laid the largest eggs in weight and size. Although early housing had a detrimental effect on average egg weight, it appeared possible to manipulate egg weight and size distribution through a combination of cage design and layer protein. Birds grouped by body weight at 8 weeks had higher uniformity, but this trait was not correlated with egg numbers or size. Moreover, housing body weights were not significantly correlated with egg size, suggesting factors other than body weight were responsible for the smaller eggs from early-housed pullets.

Rumen liquid dilution rate in dairy cows fed once daily: effects of diet and sodium bicarbonate supplementation

Three ruminally cannulated Holstein cows fed total mixed diets of hay crop silage and concentrate (30:70, 50:50, 70:30, 100:0) were used to determine liquid volume ruminal and dilution rate with polyethylene glycol as a marker. Dosing 5 h prefeeding produced nonlinear marker dilution curves that were divided into prefeeding, eating, and resting phases, whereas dosing 2 h postfeeding produced linear dilution curves. Ruminal liquid volume calculated from either dosing method overestimated liquid volume compared to manual estimates. Mean liquid dilution rates did not differ between methods of dosing, and differences between diets were closely related to dry matter intake. Supplementation with 0, 68, or 114 g/day sodium bicarbonate did not affect ruminal liquid volume or dilution rates. Across diet and buffer treatments, liquid dilution rate during eating (23 to 32%/h) was greater than mean, prefeeding, or resting dilution rates (10 to 21%/h). Correct interpretation of ruminal volume and dilution data requires full details of dosing method, dosing time in relation to feeding, and sampling times.