bluuebunny/crossref_metadata_2025 huggingface dataset:
College Students' Perceptions about Alcohol and Consensual Sexual Behavior: Alcohol Leads to Sex
Authors: Lindgren Kristen P. , Pantalone David W. , Lewis Melissa A. , George William H.
Published: August 2009

The phenomenology of college students' conceptualization of the relations between alcohol and sex are surprisingly understudied. Undergraduates rank among the most-studied populations, yet extant research largely relies on quantitative methods, which are constrained in their ability to give participants a “voice.” The current study used focus groups to investigate 14 male and 15 female undergraduates' conceptualizations of the relations between alcohol and consensual sex. Focus group themes indicated gendered and universal relations between alcohol and sex and positive and negative aspects of these relations. A robust relation between sex and alcohol was noted (men and women), and participants reported deliberately seeking out alcohol to indicate sexual willingness (women), reject sexual advances directly (women), and facilitate making sexual advances (men). Implications for educators are discussed.
Implementing Evidence-Based Substance Use Prevention Curricula with Fidelity: The Role of Teacher Training
Authors: Hanley Sean , Ringwalt Chris , Vincus Amy A. , Ennett Susan T. , Bowling J. Michael , Haws Susan W. , Rohrbach Louise A.
Published: August 2009

It is widely recognized that teacher training affects the fidelity with which evidence-based substance use prevention curricula are implemented. We present the results of a 2005 survey of teachers from a nationally representative sample of 1721 public middle schools in the U.S. (78.1% response rate). We measured fidelity along two dimensions (adherence and dose) and also assessed the number of hours, recency, and perceived effectiveness of teachers' training, as well as the degree to which adherence was emphasized during training. Among teachers using evidence-based curricula, 35.3% reported following their curriculum guide very closely. The average proportion of lessons taught was 64.9%, and only 30.2% of teachers taught all the lessons in their curriculum. Analyses revealed that teachers whose training emphasized adherence were 5 times as likely to be more adherent. We present recommendations for training-related factors that may increase fidelity of implementation.
Betel Nut Chewing Behavior among Adolescents in Eastern Taiwan: A Cluster Analysis
Authors: Chen Han-Ying , Waigandt Alex C.
Published: August 2009

The prevalence of betel nut chewing among junior high school students is highest in the eastern region of Taiwan (Lin, 1990). Although there is some research on the prevalence rate, little effort has been paid to developing a classification of betel nut chewing behavior applicable to adolescents. Eight-hundred and forty-three students, including 435 males (51.6%) and 408 females (48.4%), 552 non-aborigines (65.5%) and 291 aborigines (34.5%), completed a questionnaire concerning betel nut chewing behavior, beliefs (perceptions) toward betel nut chewing, self-esteem, and locus of control. Using a cluster analysis, this study identified 3 sub-types of betel nut chewing behaviors. They were identified as “Self-regulation oriented” (Internally controlled-oriented), “Indigenously oriented” (Taiwan culture-oriented), and “Symbolically oriented” (Externally controlled-oriented). The validity of clusters was explored in terms of gender and ethnicity. This study describes the implications for reducing betel nut chewing behaviors among adolescents.
Stakeholder Norms Toward Beaver Management in Massachusetts
Authors: JONKER SANDRA A. , ORGAN JOHN F. , MUTH ROBERT M. , ZWICK RODNEY R. , SIEMER WILLIAM F.
Published: August 2009

ABSTRACT  In Massachusetts, USA, both human and beaver (Castor Canadensis) population levels are increasing, beaver damage complaints are escalating, and beaver management options are restricted by the 1996 Wildlife Protection Act. We looked at the public's norms toward beavers in Massachusetts. In 2002 we sent a mail‐back questionnaire to a random sample of 5,563 residents in 3 geographic regions in Massachusetts and to residents who submitted a beaver complaint to Massachusetts Division of Fisheries and Wildlife (MassWildlife) in 1999–2000 (47.3% overall response rate). Respondents supported some form of beaver management. As severity of beaver damage was perceived to increase, respondents were more willing to accept lethal management and control of beavers. These results emphasize the importance of how tolerance and acceptability of wildlife are influenced by the type of activity the animal is engaged in, the type of management action that is proposed, the positive or negative perception of a species in the eye of the public, and the public's preference for future population levels. A full understanding of these 4 points will help tailor management accordingly, because this knowledge can define a threshold of acceptance by the public for anticipated management actions. Restoration of full beaver management authority to the cognizant wildlife management agency would facilitate application of normative information to determine appropriate management response for minimizing conflicts between humans and beavers.
DNA‐Based Population Demographics of Black Bears in Coastal North Carolina and Virginia
Authors: TREDICK CATHERINE A. , VAUGHAN MICHAEL R.
Published: August 2009

ABSTRACT Noninvasive genetic sampling has become a popular method for obtaining population parameter estimates for black (Ursus americanus) and brown (U. arctos) bears. These estimates allow wildlife managers to develop appropriate management strategies for populations of concern. Black bear populations at Great Dismal Swamp (GDSNWR), Pocosin Lakes (PLNWR), and Alligator River (ARNWR) National Wildlife Refuges in coastal Virginia and North Carolina, USA, were perceived by refuge biologists to be at or above cultural and perhaps biological carrying capacity, but managers had no reliable abundance estimates upon which to base population management. We derived density estimates from 3,150 hair samples collected noninvasively at each of the 3 refuges, using 6–7 microsatellite markers to obtain multilocus genotypes for individual bears. We used Program MARK to calculate population estimates from capture histories at each refuge. We estimated densities using both traditional buffer strip methods and Program DENSITY. Estimated densities were some of the highest reported in the literature and ranged from 0.46 bears/km2at GDSNWR to 1.30 bears/km2at PLNWR. Sex ratios were male‐biased at all refuges. Our estimates can be directly utilized by biologists to develop effective strategies for managing and maintaining bears at these refuges, and noninvasive methods may also be effective for monitoring bear populations over the long term.
Deer Responses to Sounds From a Vehicle‐Mounted Sound‐Production System
Authors: VALITZSKI SHARON A. , D'ANGELO GINO J. , GALLAGHER GEORGE R. , OSBORN DAVID A. , MILLER KARL V. , WARREN ROBERT J.
Published: August 2009

ABSTRACT  We evaluated efficacy of sound as a deterrent for reducing deer (Odocoileus spp.)–vehicle collisions by observing behavioral responses of free‐ranging white‐tailed deer (O. virginianus) to pure‐tone sounds within their documented range of hearing. Behavior of free‐ranging deer within 10 m of roadways was not altered in response to a moving automobile fitted with a sound‐producing device and speakers that produced 5 sound treatments documented to be within the hearing range of white‐tailed deer. Many commercially available, vehicle‐mounted auditory deterrents (i.e., deer whistles) are purported to emit continuous pure‐tone sounds similar to those we tested. However, our data suggest that deer whistles are likely not effective in altering deer behavior in a manner that would prevent deer‐vehicle collisions.
Terrestrial Passive Integrated Transponder Antennae for Tracking Small Animal Movements
Authors: CHARNEY NOAH D. , LETCHER BENJAMIN H. , HARO ALEX , WARREN PAIGE S.
Published: August 2009

ABSTRACT  Measuring terrestrial movements of small animals poses a substantial technological challenge. We developed very long (up to 130 m) passive integrated transponder (PIT) detectors with which we tracked salamanders (Caudata) migrating from breeding ponds to their upland habitat >200 m away. In all 60 trials, salamanders were detected when released near the antennae. In a second test, we tracked 7 of 14 tagged marbled salamanders (Ambystoma opacum) migrating >65 m, well beyond the area protected by existing wetland buffer regulations in Massachusetts, USA. The mean rate of movement for these salamanders (x̄ = 0.9 m/min; SE = 0.1 m/min) was substantially higher than rates of movement reported for related salamanders with radio‐implants. These PIT antennae offer researchers a means to study small animal movements with less disruption of the animals’ natural movement patterns than is caused by other available techniques.
Impact of Clutch Relocation on Green Turtle Offspring
Authors: PINTUS KATHRYN J. , GODLEY BRENDAN J. , MCGOWAN ANDREW , BRODERICK ANNETTE C.
Published: August 2009

ABSTRACT  For species with temperature‐dependent sex determination, such as marine turtles, global climate change poses numerous threats. At the nesting beach, rising temperatures are predicted to further skew already female‐biased sex ratios and increase embryonic mortality; sea‐level rise and resultant coastal squeeze may leave few alternative breeding habitats in developed regions. As a result, clutch relocation, a commonly used management tool to reduce egg loss, may become necessary for safeguarding populations. Although studies have examined the impact of relocation on clutch success, few have examined the impact of this practice on the sex or phenotypic characteristics of hatchlings produced. We used a randomized block design experiment to examine effects of relocation on green turtle (Chelonia mydas) clutches. We compared hatching success, thermal conditions, and size (length and mass) of hatchlings from in situ control clutches with those subjected to 2 relocation methods, while controlling for maternal and other environmental effects. Relocated clutches did not vary significantly from control clutches in incubation temperature or inferred sex ratios during the critical middle third of incubation when sex is thought to be determined. Hatchling size was also unaffected by relocation. Both relocation methods, however, resulted in a 20% reduction in hatching success in comparison to in situ clutches. Clutch relocation is, however, likely to affect the population primary sex ratio, when clutches are relocated from sites in proximity to the sea where tidal inundation is a threat. Here, cooler conditions are likely to produce more males than are the warmer female‐producing temperatures higher up the beach. For clutches at risk, relocation is a viable process and does not appear to affect hatchling size or predicted sex ratios if relocation sites are selected in areas utilized by other females. We urge caution, however, when moving clutches from potentially male‐producing sites, particularly given predicted impacts of climate change on already female‐biased sex ratios.
Designating Seasonality Using Rate of Movement
Authors: WAL ERIC VANDER , RODGERS ARTHUR R.
Published: August 2009

ABSTRACT Traditionally, seasons for animals have been designated based on single external variables such as climate or plant phenology, rather than an animal's response to the dynamic environments within which it lives. By interpreting a rate of movement function of cumulative movement through time we established a method that distinguishes transitions between behaviors limited by winter habitat conditions from those present during summer. Identification of these time periods provides temporal definition to subsequent home‐range analyses and use‐availability comparisons. We used location data from 32 Global Positioning System‐collared female moose (Alces alces) to demonstrate the method. We used model selection (Akaike's Information Criterion) to differentiate between candidate rate of movement response curves. Of 32 moose, 29 clearly conformed to an annual movement pattern described by a logistic curve, with increased rates of movement in summer compared to winter. Conversely, 3 aberrant individuals did not alter their movement rate through the year and were best fit with a linear response curve. The seasonal rate of movement model we developed suggests an average summer period of 122 days (median = 119 days, range = 96–173 days) for moose in northwestern Ontario, Canada. The rate of movement model we applied to individuals indicated 1 May as the median date for the winter‐summer transition (range = 2 Apr–24 May), and the median transition from summer to winter was 25 August (range = 1 Aug–23 Oct). Wide variation in timing and duration of summer and winter seasons among individuals demonstrates potential failure of the single external variable approach to capture the suite of factors potentially influencing animal behaviors. By plotting cumulative distance moved throughout the year, we elucidated individual variation in response to known and unknown variables that affect animal movement. Accounting for variability among individuals in designation of biologically significant temporal boundaries is critical to delineation of seasonally important habitats for conservation and sustainability of healthy wildlife populations.
Evaluation of Total Body Electrical Conductivity to Estimate Body Composition of a Small Mammal
Authors: REYNOLDS D. SCOTT , SULLIVAN JAMES C. , KUNZ THOMAS H.
Published: August 2009

ABSTRACT  The ability to measure body composition is critical for studying the physiological ecology of animals. This is particularly true for small mammals that have a high metabolic rate. We evaluated a nondestructive method of body composition analysis that would allow accurate assessment of body fat, body water, and lean mass. We used total body electrical conductivity (TOBEC) to estimate body composition in the little brown myotis (Myotis lucifugus). In a sample of 46 individuals, TOBEC was both accurate and precise in estimating total body water and lean mass but was less effective at estimating total body fat. Mass‐independent or whole‐body compartments (i.e., total body water, total body fat, lean dry mass, and lean body mass) were more accurately estimated than mass‐dependent or mass‐specific body composition compartments (i.e., water content, fat index, and % lean dry mass). The TOBEC measurements we made using an SA‐3000 analyzer were influenced by extremes in body temperature, as well as by aluminum and incoloy wing bands. Our study also presents a new method of restraint especially suited for small mammals and birds that increases precision of TOBEC measurements. This study shows that TOBEC is a potentially valuable tool for studying changes in body composition of small mammals and may provide insight into the physiological impacts of various life history stages such as postnatal growth, reproduction, and hibernation.
Habitat Use and Selection by California Spotted Owls in a Postfire Landscape
Authors: BOND MONICA L. , LEE DEREK E. , SIEGEL RODNEY B. , WARD JAMES P.
Published: August 2009

ABSTRACT Forest fire is often considered a primary threat to California spotted owls (Strix occidentalis occidentalis) because fire has the potential to rapidly alter owl habitat. We examined effects of fire on 7 radiomarked California spotted owls from 4 territories by quantifying use of habitat for nesting, roosting, and foraging according to severity of burn in and near a 610‐km2fire in the southern Sierra Nevada, California, USA, 4 years after fire. Three nests were located in mixed‐conifer forests, 2 in areas of moderate‐severity burn, and one in an area of low‐severity burn, and one nest was located in an unburned area of mixed‐conifer‐hardwood forest. For roosting during the breeding season, spotted owls selected low‐severity burned forest and avoided moderate‐ and high‐severity burned areas; unburned forest was used in proportion with availability. Within 1 km of the center of their foraging areas, spotted owls selected all severities of burned forest and avoided unburned forest. Beyond 1.5 km, there were no discernable differences in use patterns among burn severities. Most owls foraged in high‐severity burned forest more than in all other burn categories; high‐severity burned forests had greater basal area of snags and higher shrub and herbaceous cover, parameters thought to be associated with increased abundance or accessibility of prey. We recommend that burned forests within 1.5 km of nests or roosts of California spotted owls not be salvage‐logged until long‐term effects of fire on spotted owls and their prey are understood more fully.
Depletion of Rice as Food of Waterfowl Wintering in the Mississippi Alluvial Valley
Authors: GREER DANIELLE M. , DUGGER BRUCE D. , REINECKE KENNETH J. , PETRIE MARK J.
Published: August 2009

ABSTRACT  Waterfowl habitat conservation strategies in the Mississippi Alluvial Valley (MAV) and several other wintering areas assume carrying capacity is limited by available food, and increasing food resources is an effective conservation goal. Because existing research on winter food abundance and depletion is insufficient to test this hypothesis, we used harvested rice fields as model foraging habitats to determine if waste rice seed is depleted before spring migration. We sampled rice fields (n = 39 [winter 2000–2001], n = 69 [2001–2002]) to estimate seed mass when waterfowl arrived in late autumn and departed in late winter. We also placed exclosures in subsets of fields in autumn (n = 8 [2000–2001], n = 20 [2001–2002]) and compared seed mass inside and outside exclosures in late winter to estimate rice depletion attributable to waterfowl and other processes. Finally, we used an experiment to determine if the extent of rice depletion differed among fields of varying initial abundance and if the seed mass at which waterfowl ceased foraging or abandoned fields differed from a hypothesized giving‐up value of 50 kg/ha. Mean seed mass was greater in late autumn 2000 than 2001 (127.0 vs. 83.9 kg/ha; P = 0.018) but decreased more during winter 2000–2001 than 2001–2002 (91.3 vs. 55.7 kg/ha) and did not differ at the end of winter (35.8 vs. 28.3 kg/ha; P = 0.651). Assuming equal loss to deterioration inside and outside exclosures, we estimated waterfowl consumed 61.3 kg/ha (48.3%) of rice present in late autumn 2000 and 21.1 kg/ha (25.1%) in 2001. When we manipulated late‐autumn rice abundance, mean giving‐up mass of rice seed was similar among treatments (48.7 kg/ha; P = 0.205) and did not differ from 50 kg/ha (P = 0.726). We integrated results by constructing scenarios in which waterfowl consumed rice at different times in winter, consumption and deterioration were competing risks, and consumption occurred only above 50 kg/ha. Results indicated waterfowl likely consumed available rice soon after fields were flooded and the amount consumed exceeded our empirical estimates but was ≤48% (winters pooled) of rice initially present. We suggest 1) using 50 kg/ha as a threshold below which profitability limits waterfowl feeding in MAV rice fields; 2) reducing the current estimate (130 kg/ha) of rice consumed in harvested fields to 47.1 kg/ha; and 3) increasing available rice by increasing total area of fields managed, altering management practices (e.g., staggered flooding), and exploring the potential for producing second or ratoon rice crops for waterfowl.
Evaluation of Camera Trapping for Estimating Red Fox Abundance
Authors: SARMENTO PEDRO , CRUZ JOANA , EIRA CATARINA , FONSECA CARLOS
Published: August 2009

ABSTRACT  The nature reserve Serra da Malcata, Portugal, was recently considered a site for Iberian lynx (Lynx pardinus) reintroduction. Because of potential disease risk posed by red foxes (Vulpes vulpes) in the area, a reliable estimate of fox abundance was critical for a dependable reintroduction program. We adapted camera‐trapping techniques for estimating red fox abundance in the reserve. From July 2005 to August 2007, we conducted 7 camera‐trapping sessions, allowing for individual identification of foxes by physical characteristics. We estimated abundance using the heterogeneity (Mh) model of the software program CAPTURE. Estimated density ranged from 0.91 ± 0.12 foxes/km2to 0.74 ± 0.02 foxes/km2. By estimating red fox density, it is possible to define the number of foxes that must be sampled to assess the presence of potential fox‐transmitted diseases that may affect lynx reintroduction.
Puncture‐Resistance of Gloves for Handling Bats
Authors: FREEMAN PATRICIA W. , LEMEN CLIFF A.
Published: August 2009

ABSTRACT  We quantified protection given by a variety of gloves against bat bites by using steel indenters to simulate teeth and measuring forces needed to puncture the gloves. Level of protection given by gloves was compared to expected bite forces and tooth sharpness of bats. Cotton, plastic‐coated synthetic fabric, and proprietary materials advertised as puncture‐ and cut‐resistant were easy to penetrate compared to leather gloves. Split leather gives the highest level of protection, but with reduced dexterity. These are best for handling larger bats (>40 g) or if higher safety is preferred. Deerskin gives reasonable protection without much loss in dexterity for handling bats <40 g.
Energy Budgets for Eared Grebes on the Great Salt Lake and Implications for Harvest of Brine Shrimp
Authors: CONOVER MICHAEL R. , CAUDELL JOE N.
Published: August 2009

ABSTRACT  About 1.5‐million eared grebes (Podiceps nigricollis), representing half of the North American population, stage on Utah's Great Salt Lake, USA (GSL) during autumn migration to forage on brine shrimp (Artemia franciscana). Indirectly competing with birds for brine shrimp are commercial harvesters who annually collect >1 million kg (dry wt) of shrimp cysts (i.e., hardened eggs), an amount that during some years equals up to half of all brine shrimp cysts produced annually on the GSL. No information was available regarding what impact this commercial harvest was having on eared grebes. We determined daily energy requirements of eared grebes so that regulations governing brine shrimp cyst harvest would better reflect foraging needs of grebes. We measured basal metabolic rate (BMR) of eared grebes from June 2000 to October 2000. Mean BMR of 106 adult and subadult eared grebes was 0.023 kJ/g/hour (SD = 0.004), and mean BMR of 37 juveniles was 0.024 kJ/g/hour (SD = 0.003). Resting and preening metabolic rates were 1.2 times higher than BMR, whereas diving‐bout metabolic rate was 1.7 times higher than BMR. Daily energy needs of an average‐sized grebe (550 g) during November were 391 kJ. Meeting this energy need requires daily consumption of 24,400 adult brine shrimp. In addition, grebes must consume 2,100–5,200 adult shrimp daily to obtain enough energy reserves to continue their migration to California, USA, and Mexico. Hence, grebes need to consume 26,500–29,600 adult brine shrimp daily while staging on GSL. To achieve this high harvest rate, grebes need adult brine shrimp densities at >380 shrimp/m3during autumn. Commercial harvest of brine shrimp cysts from GSL should be curtailed when cyst densities fall below 20,000 cysts/m3to ensure enough adult brine shrimp for grebes during the subsequent year.
Comparison of Methods of Monitoring Wildlife Crossing‐Structures on Highways
Authors: FORD ADAM T. , CLEVENGER ANTHONY P. , BENNETT ANDREW
Published: August 2009

ABSTRACT  Wildlife crossing‐structures (e.g., underpasses and overpasses) are used to mitigate deleterious effects of highways on wildlife populations. Evaluating performance of mitigation measures depends on monitoring structures for wildlife use. We analyzed efficacy of 2 noninvasive methods commonly used to monitor crossing‐structure use by large mammals: tracking and motion‐activated cameras. We monitored 15 crossing‐structures every other day between 29 June and 24 October 2007 along the Trans‐Canada Highway in Alberta, Canada. Our objectives were to determine how species‐specific detection rates are biased by the detection method used, to determine factors contributing to crossing‐event detection, and to evaluate the most cost‐effective approach to monitoring. We detected 3,405 crossing events by tracks and 4,430 crossings events by camera for mammals coyote‐sized and larger. Coyotes (Canis latrans) and grizzly bears (Ursus arctos) were significantly more likely to be detected by track‐pads, whereas elk (Cervus elaphus) and deer (Odocoileus sp.) were more likely to be detected by cameras. Crossing‐event detection was affected by species, track‐pad length, and number of animals using the crossing structure. At the levels of animal activity observed in our study our economic analysis indicates that cameras are more cost‐effective than track‐pads for study durations >1 year. Understanding the benefits and limitations of camera and track‐pad methods for monitoring large mammal movement at wildlife crossing‐structures will help improve the efficiency of studies designed to evaluate the effectiveness of highway mitigation measures.
Capture and Mortality Rates of Ducks in Selected Trap Types
Authors: DIETER C. D. , MURANO R. J. , GALSTER D.
Published: August 2009

ABSTRACT  We evaluated different trap styles and related mortality of trapped ducks (Anas spp.) for 3 field seasons as part of the United States‐Canada Cooperative Waterfowl Banding Program. During 2002, we evaluated 4 trap designs and caught 10,966 ducks. Trap style affected capture rates (P = 0.018, F5 = 9.02), with Benning II and oval traps catching more ducks than cloverleaf and star traps. In 2003, we tested 3 trap styles and caught 10,849 ducks. Trap style affected duck capture rates (P < 0.01, F5 = 15.16), with oval traps with 6‐m lead panels catching more ducks than Benning II traps and cloverleaf traps. During 2004, we tested 3 trap styles and caught 11,737 ducks. Trap style affected capture rates (P < 0.01, F5 = 11.23), with oval traps with 6‐m leads catching more ducks than either the oval trap without leads or Benning II traps. Trap style affected mortality rates of ducks, but overall mortality of trapped ducks was low with a rate of 1.16% in 2002, 0.32% in 2003, and 0.17% in 2004; mortality was not a major problem in our study. Waterfowl managers may be able to catch more ducks using oval traps with leads without increasing mortality of captured ducks.
Bird Response to Prescribed Silvicultural Treatments in Bottomland Hardwood Forests
Authors: TWEDT DANIEL J. , SOMERSHOE SCOTT G.
Published: August 2009

ABSTRACT  Silvicultural treatments prescribed to enhance wildlife habitat by promoting structural heterogeneity via retention of large live trees, snags, and coarse woody debris has been termed wildlife‐forestry. Wildlife‐forestry has been advocated for management of bottomland hardwood forests on public conservation lands within the Mississippi Alluvial Valley, USA. On Tensas River National Wildlife Refuge in northeast Louisiana, we used distance sampling during 6 visits to 138 point locations to estimate avian densities within stands subjected to variable‐retention harvests, within a 13‐year chronosequence, and untreated control stands. Densities of 9 species, including 6 species of conservation concern, were greater in treated stands than on untreated stands. Five species responded negatively to treatments and had greater densities in untreated control stands. Based on conservation concern scores established by Partners in Flight and annual detections of each of 30 species, treated stands afforded greater community‐wide bird conservation than did untreated stands. For most species, maximum treatment response was between 5 years and 8 years posttreatment with duration of treatment effect <13 years. Therefore, habitat conditions on treated stands should be reevaluated at circa 15‐year intervals and, if warranted, additional silvicultural treatment prescribed to rejuvenate habitat conditions.
Habitat Quality Following Mid‐Rotation Treatment in Conservation Reserve Program Pines
Authors: JONES PHILLIP D. , MIXON MELINDA R. , DEMARAIS STEPHEN
Published: August 2009

ABSTRACT  Evaluation of habitat management practices at mid‐rotation is needed for pine (Pinus spp.) plantations enrolled in cost‐share programs. Plantations established in abandoned agricultural fields may have different understory plant communities than those with a long history of forest cover. Mid‐rotation pine plantations often have a hardwood midstory that limits development of early succession habitat components important to white‐tailed deer (Odocoileus virginianus; deer) and northern bobwhite (Colinus virginianus; bobwhite). We treated with imazapyr herbicide and prescribed burning (HB) 11 thinned, 13–22‐year‐old pine plantations in the Upper East Gulf Coastal Plain of Mississippi, USA, enrolled in cost‐share programs, and we sampled plant community response during the summers of 2003 and 2004, years 1 and 2 posttreatment. The HB treatment created a more open structure with greater coverage of debris and herbaceous plants than in controls. Increased forb coverage in HB plots yielded a more seasonally diverse foraging base for deer. Horizontal screening cover developed slowly in HB plots and was more abundant in control plots. Autumn and winter food‐plant coverage for bobwhite was provided by either treatment, but accessibility was improved in HB plots relative to controls. Bobwhite nesting cover was improved by HB relative to controls but was still of marginal quality. Brood‐rearing habitat was precluded in both treatments due to lack of bare ground. Our results indicate that imazapyr followed by prescribed fire is a beneficial tool for creating early succession habitat for deer and bobwhite in mid‐rotation pine plantations with a history of agricultural use. Continued management with periodic prescribed fire and overstory thinning should be instituted to maintain and perhaps improve these conditions.
New Technology for Estimating Seed Production of Moist‐Soil Plants
Authors: GRAY MATTHEW J. , FOSTER MELISSA A. , PENICHE LUIS A. PEÑA
Published: August 2009

ABSTRACT  Waterfowl biologists estimate seed production in moist‐soil wetlands to calculate duck‐energy days (DEDs) and evaluate management techniques. Previously developed models that predict plant seed yield using morphological measurements are tedious and time consuming. We developed simple linear regression models that indirectly and directly related seed‐head area to seed production for 7 common moist‐soil plants using portable and desktop scanners and a dot grid, and compared time spent processing samples and predictive ability among models. To construct models, we randomly collected approximately 60 plants/species at the Tennessee National Wildlife Refuge, USA, during September 2005 and 2006, threshed and dried seed from seed heads, and related dry mass to seed‐head area. All models explained substantial variation in seed mass (R2< 0.87) and had high predictive ability (R2predicted < 0.84). Processing time of seed heads averaged 22 and 3 times longer for the dot grid and portable scanner, respectively, than for the desktop scanner. We recommend use of desktop scanners for accurate and rapid estimation of moist‐soil plant seed production. Seed predictions per plant from our models can be used to estimate total seed production and DEDs in moist‐soil wetlands.
Scent‐Matching Dogs Determine Number of Unique Individuals From Scat
Authors: WASSER SAMUEL K. , SMITH HEATH , MADDEN LINDSAY , MARKS NATHANIEL , VYNNE CARLY
Published: August 2009

ABSTRACT  Noninvasive scat sampling methods can generate large samples sizes, collected over vast landscapes, ideal for addressing wildlife conservation and management questions. However, the cost of genotyping scat samples limits the accessibility of these techniques. We describe detection‐dog methods for matching large numbers of scat samples to the individual, reducing or eliminating the need for sample genotyping. Three dogs correctly matched 25 out of 28 samples from 6 captive maned wolves (Chrysocyon brachyurus) of known identity. Sample scent‐matching can increase overall accessibility and breadth of applications of noninvasive scat‐collection methods to important landscape scale problems in wildlife sciences.
Expression of the NH2-Terminal Fragment of RasGAP in Pancreatic β-Cells Increases Their Resistance to Stresses and Protects Mice From Diabetes
Authors: Yang Jiang-Yan , Walicki Jöel , Jaccard Evrim , Dubuis Gilles , Bulat Natasa , Hornung Jean-Pierre , Thorens Bernard , Widmann Christian
Published: August 2009

OBJECTIVE

Our laboratory has previously established in vitro that a caspase-generated RasGAP NH2-terminal moiety, called fragment N, potently protects cells, including insulinomas, from apoptotic stress. We aimed to determine whether fragment N can increase the resistance of pancreatic β-cells in a physiological setting.

RESEARCH DESIGN AND METHODS

A mouse line, called rat insulin promoter (RIP)-N, was generated that bears a transgene containing the rat insulin promoter followed by the cDNA-encoding fragment N. The histology, functionality, and resistance to stress of RIP-N islets were then assessed.

RESULTS

Pancreatic β-cells of RIP-N mice express fragment N, activate Akt, and block nuclear factor κB activity without affecting islet cell proliferation or the morphology and cellular composition of islets. Intraperitoneal glucose tolerance tests revealed that RIP-N mice control their glycemia similarly as wild-type mice throughout their lifespan. Moreover, islets isolated from RIP-N mice showed normal glucose-induced insulin secretory capacities. They, however, displayed increased resistance to apoptosis induced by a series of stresses including inflammatory cytokines, fatty acids, and hyperglycemia. RIP-N mice were also protected from multiple low-dose streptozotocin-induced diabetes, and this was associated with reduced in vivo β-cell apoptosis.

CONCLUSIONS

Fragment N efficiently increases the overall resistance of β-cells to noxious stimuli without interfering with the physiological functions of the cells. Fragment N and the pathway it regulates represent, therefore, a potential target for the development of antidiabetes tools.
Learner Performance in Multimedia Learning Arrangements: An Analysis Across Instructional Approaches
Authors: Eysink Tessa H. S. , de Jong Ton , Berthold Kirsten , Kolloffel Bas , Opfermann Maria , Wouters Pieter
Published: August 2009

In this study, the authors compared four multimedia learning arrangements differing in instructional approach on effectiveness and efficiency for learning: (a) hypermedia learning, (b) observational learning, (c) self-explanation–based learning, and (d) inquiry learning. The approaches all advocate learners’ active attitude toward the learning material but show differences in the specific learning processes they intend to foster. Learning results were measured on different types of knowledge: conceptual, intuitive, procedural, and situational. The outcomes show that the two approaches asking learners to generate (parts of) the subject matter (either by self-explanations or by conducting experiments) led to better performance on all types of knowledge. However, results also show that emphasis on generating subject matter by the learner resulted in less efficient learning.
Endoscopic endonasal transclival resection of chordomas: operative technique, clinical outcome, and review of the literature
Authors: Fraser Justin F. , Nyquist Gurston G. , Moore Nicholas , Anand Vijay K. , Schwartz Theodore H.
Published: August 2009

Object

Transcranial approaches to clival chordomas provide a circuitous route to the site of origin of the tumor often involving extensive bone drilling and brain retraction, which places critical neurovascular structures between the surgeon and pathology. For certain chordomas, the endonasal endoscopic transclival approach is a novel minimal access, but it is an equally aggressive alternative providing the most direct route to the tumor epicenter.

Methods

The authors present a consecutive series of patients undergoing endonasal endoscopic resection of clival chordomas. Extent of resection was determined by postoperative volumetric MR imaging and divided into > 95% and < 95%.

Results

Seven patients underwent 10 operations. Preoperative cranial neuropathies were present in 4. The mean patient age was 52.0 years. The mean tumor volume was 34.9 cm3. Intraoperative lumbar drainage was used in 1 patient, and the tumors extended intradurally in 3. One patient underwent 2 intentionally palliative procedures for subtotal debulking. Greater than 95% resection was achieved in 7 of 8 operations in which radical resection was the goal (87%). All tumors with volumes < 50 cm3 had > 95% resection (p = 0.05). The overall mean follow-up was 18.0 months. Cranial neuropathies resolved in all 3 patients with cranial nerve VI palsies. One patient with recurrent nasopharyngeal chordoma died of disease progression; another experienced 2 recurrences before receiving radiation therapy. All surviving patients remain progression free. There were no intraoperative complications; however, 1 patient developed a pulmonary embolus postoperatively. There were no postoperative CSF leaks.

Conclusions

The endonasal endoscopic transclival approach represents a less invasive and more direct approach than a transcranial approach to treat certain moderate-sized midline skull base chordomas. Longer follow-up is necessary to determine comparability to transcranial approaches for long-term control. Large tumors with significant extension lateral to the carotid artery may not be suitable for this approach.
Usefulness of composite methionine–positron emission tomography/3.0-tesla magnetic resonance imaging to detect the localization and extent of early-stage Cushing adenoma
Authors: Ikeda Hidetoshi , Abe Takehiko , Watanabe Kazuo
Published: August 2009

Object

Fifty to eighty percent of Cushing disease is diagnosed by typical endocrine responses. Recently, the number of diagnoses of Cushing disease without typical Cushing syndrome has been increasing; therefore, improving ways to determine the localization of the adenoma and making an early diagnosis is important. This study was undertaken to determine the present diagnostic accuracy for Cushing microadenoma and to compare the differences in diagnostic accuracy between MR imaging and PET/MR imaging.

Methods

During the past 3 years the authors analyzed the diagnostic accuracy in a series of 35 patients with Cushing adenoma that was verified by surgical pituitary exploration. All 35 cases of Cushing disease, including 20 cases of “overt” and 15 cases of “preclinical” Cushing disease, were studied. Superconductive MR images (1.5 or 3.0 T) and composite images from FDG-PET or methionine (MET)–PET and 3.0-T MR imaging were compared with the localization of adenomas verified by surgery.

Results

The diagnostic accuracy of superconductive MR imaging for detecting the localization of Cushing microadenoma was only 40%. The causes of unsatisfactory results for superconductive MR imaging were false-negative results (10 cases), false-positive results (6 cases), and instances of double pituitary adenomas (3 cases). In contrast, the accuracy of microadenoma localization using MET-PET/3.0-T MR imaging was 100% and that of FDG-PET/3.0-T MR imaging was 73%. Moreover, the adenoma location was better delineated on MET-PET/MR images than on FDG-PET/MR images. There was no significant difference in maximum standard uptake value of adenomas evaluated by MET-PET between preclinical Cushing disease and overt Cushing disease.

Conclusions

Composite MET-PET/3.0-T MR imaging is useful for the improvement of the delineation of Cushing microadenoma and offers high-quality detectability for early-stage Cushing adenoma.
Endoscopic repair of cerebrospinal fluid leaks in the lateral sphenoid sinus recess
Authors: Forer Boaz , Sethi Dharmbir S.
Published: August 2009

Object

Cerebrospinal fluid leaks may occur as a result of trauma or following surgery, and occasionally may also be spontaneous. Leakage of CSF from the lateral sphenoid recess is rare and challenging to treat. The authors present their experience with repairs of 10 CSF leaks that were confined to the lateral sphenoid recess and were treated at the Singapore General Hospital.

Methods

A retrospective chart review was conducted for all patients who underwent operations for lateral sphenoid recess CSF leaks between 2001 and 2008.

Results

Ten repairs were performed in 8 patients by using a transpterygoid approach, with a 90% success rate. In 3 cases the transcranial approach had failed prior to endoscopic repair. “Sandwich reconstruction” under direct vision was performed in all cases, and was completed using cartilage or bone as a rigid support.

Conclusions

This series demonstrates that CSF leakage can be managed safely and effectively by using an endoscopic transpterygoid approach in patients in whom both external and endoscopic attempts have failed. The transpterygoid approach used in all of the cases in this series provides wide exposure around the skull base defect, which is crucial for successful repair.
Safety and efficacy of vascular tumor embolization using Onyx: is angiographic devascularization sufficient?
Authors: Elhammady Mohamed Samy , Wolfe Stacey Quintero , Ashour Ramsey , Farhat Hamad , Moftakhar Roham , Lieber Baruch B. , Aziz-Sultan Mohammad Ali
Published: August 2009

Object

The authors assessed the safety and efficacy of embolization of head, neck, and spinal tumors with Onyx and determined the correlation between tumor embolization and intraoperative blood loss.

Methods

The authors prospectively collected all head, neck, and spinal tumors embolized with Onyx at their institution over a 28-month period. Information on tumor type, location, extent of tumor devascularization, endovascular and surgical complications, and intraoperative estimated blood loss (EBL) was evaluated.

Results

Forty-three patients with various head, neck, and spinal lesions underwent vascular tumor embolization with Onyx. Indications for embolization included uncontrolled tumor bleeding in 8 cases, elective preoperative devascularization in 34, and tumor-induced consumptive thrombocytopenia in 1 case. Embolization was performed via direct tumoral puncture in 14 cases and through the traditional transarterial route in the remaining lesions. Embolization was successful in ending uncontrolled tumor bleeding in all 8 cases and in reversing the consumptive coagulopathy in 1 case. Intraparenchymal penetration of embolic material was possible in all percutaneously embolized tumors and in 4 of the 20 tumors embolized preoperatively via the transarterial route. The mean percentage of devascularization in tumors with intraparenchymal penetration of Onyx was 90.3% compared with 83.7% in tumors without intraparenchymal penetration. The mean EBL with intraparenchymal penetration of Onyx was significantly lower than when there was no intraparenchymal penetration (459 vs 2698 ml; p = 0.0067). There were no neurological complications related to the embolization procedures.

Conclusions

Embolization of vascular tumors with Onyx can be performed safely but may not reach optimal effectiveness in reducing intraoperative EBL if the embolic material does not penetrate the tumor vasculature. In the authors' experience, the best method of intraparenchymal penetration is achieved with direct tumor puncture. Transarterial embolization may not result in tumor penetration, particularly when injected from a long distance through small caliber or slow flow vessels.
Seizures after evacuation of subdural hematomas: incidence, risk factors, and functional impact
Authors: Rabinstein Alejandro A. , Chung Seung Young , Rudzinski Leslie A. , Lanzino Giuseppe
Published: August 2009

Object

The purpose of this study was to evaluate the incidence of seizures or epileptiform abnormalities on electroencephalography (EEG) studies in patients undergoing surgical treatment for acute subdural hematoma (SDH).

Methods

This was a retrospective study of 134 consecutive patients with acute or acute-on-chronic SDH who underwent surgical treatment at the authors' institution between January 2004 and July 2008. Detailed information was collected regarding baseline clinical data (including preexistent functional impairment); Glasgow Coma Scale (GCS) sum scores before and 24 hours after surgery; presence of clinical seizures; EEG findings; and functional outcome on discharge and up to the 6-month follow-up. All brain CT scans were reviewed to calculate SDH volume and midline shift. The Glasgow Outcome Scale (GOS) score was used for functional assessment, and GOS scores of 1–3 were considered indicative of poor outcome. Univariate and multivariate logistic regression analyses were performed to identify statistical associations.

Results

Clinical seizures or epileptiform changes on EEG were observed during the acute postoperative period in 33 patients (25%). Preexistent functional impairment and seizures/epileptiform EEG findings after surgery were independently associated with poor functional outcome upon hospital discharge (p < 0.001 for both). Preexistent functional impairment (p < 0.001), lower GCS score before surgery (p = 0.04), and lower GCS score 24 hours after surgery (p = 0.007), but not seizures/epileptiform EEG findings, were independently associated with poor functional recovery at 1- to 6-month follow-up evaluations. Seizures/epileptiform EEG findings had a strong association with lower GCS scores after surgery (p = 0.01), and they were more common in patients who underwent evacuation by craniotomy (p = 0.02).

Conclusions

Epileptic complications are common after acute SDH evacuation, and should be suspected in patients with an unanticipated depressed level of consciousness after surgery. Seizures worsen early functional outcome, but delayed favorable recovery is possible. Therefore, one should be cautious when discussing prognosis in the early postoperative period of patients with epileptic complications.
Evaluation of ventriculomegaly using diffusion tensor imaging: correlations with chronic hydrocephalus and atrophy
Authors: Osuka Satoru , Matsushita Akira , Yamamoto Tetsuya , Saotome Kousaku , Isobe Tomonori , Nagatomo Yasushi , Masumoto Tomohiko , Komatsu Yoji , Ishikawa Eiichi , Matsumura Akira
Published: August 2009

Object

Ventriculomegaly is a common imaging finding in many types of conditions. It is difficult to determine whether it is related to true hydrocephalus or to an atrophic process by using only imaging procedures such as MR imaging after traumatic injury, stroke, or infectious disease. Diffusion tensor (DT) imaging can distinguish the compression characteristics of white matter, indicating that increased diffusion anisotropy may be related to white matter compression. In this preliminary study, the authors compared the DT imaging findings of ventriculomegaly with those of chronic hydrocephalus or atrophy to clarify the potential of diffusion anisotropy in the identification of hydrocephalus.

Methods

Ten patients with chronic hydrocephalus, 8 patients with atrophy (defined by conventional devices and surgical outcome), and 14 healthy volunteers underwent DT imaging. Images were acquired before and after shunting or once in cases without shunting. The fractional anisotropy (FA) values at many points around the lateral ventricle were evaluated.

Results

The FA patterns around the lateral ventricle in the chronic hydrocephalus and atrophy groups were different. Especially in the caudate nucleus, FA was increased in the chronic hydrocephalus group compared with the atrophy group. Furthermore, the FA values returned to normal levels after shunt placement.

Conclusions

Assessment of the FA value of the caudate nucleus may be an important, less invasive method for distinguishing true hydrocephalus from ventriculomegaly. Further research in a large number of patients is needed to verify the diagnostic ability of this method.