bluuebunny/crossref_metadata_2025 huggingface dataset:
Downhole Gas Separation and Injection Powered by a Downhole Turbo Expander
Authors: Brady J. L. , Klein J. M. , Stevenson M. D. , Petullo S. P. , D’Orsi N. C. , Skinner R. C. , Eager K. D. , Perry R. A.
Published: June 2009

A downhole gas compressor and turbine expander are being developed to inject excess gas into North Slope fields. North Slope oil fields and some oil and condensate fields elsewhere in the world are limited in liquid hydrocarbon production because of surface gas processing facility limitations. These fields usually require costly surface facilities to process, compress and reinject the produced gas.

The Subsurface Process And Reinjection Compressor (SPARC) concept uses the excess production pressure (energy) that is usually wasted across a choke to generate power through a downhole turbo expander that runs a downhole gas compressor to reinject a portion of the gas stream. The system consists of a downhole separator, compressor, turbo-expander and other standard downhole equipment for the necessary plumbing.

Two basic machines are being developed: one operates in parallel flow and the second operates in series flow. The parallel flow machine maintains the highest pressure possible throughout in order to inject the maximum amount of gas. A separator divides the production into two streams. The first stream, which consists of liquids and a portion of the gas, is used for power generation. The second stream, dry gas at separator conditions, is compressed and injected into another reservoir or isolated zone that the wellbore penetrates. The amount of gas injection depends upon the amount of excess energy that is available. Typically, North Slope wells can reinject from 30% to 60% of the gas downhole without the gas being produced to the surface.

The second machine operates in series flow. The entire liquid and gas stream is passed through a turbo expander and then a portion of the gas is separated for reinjection. The series machine allows for the maximum cooling and pressure reduction to recover a significant fraction of the condensate from the gas stream prior to gas separation and reinjection. The series machine reinjects less gas than the parallel machine but it will recover a higher percentage of the condensate in the produced gas. Therefore the series machine may be the more economical machine to use in a condensate reservoir.

The development of the SPARC is requiring significant advances in compressor, turbo-expander, separator and packer technology. Current designs show that the SPARC can be made small enough to be placed through 3-1/2" tubing into liners as large as 7" via wireline. The primary advantage of the SPARC is that it can provide additional gas injection capacities at a fraction of the capital cost of traditional surface equipment.
Well Completions are Especially Important in Permian Basin Limestone and Dolomite Wells
Authors: Brown D.C.
Published: June 2009

Completion procedures in the Permian Basin, especially in limestone, dolomite, and reef formations, can be tremendously important in determining a well's producing rate and economic return. Every well should be considered as a separate problem, with due thought given to the need for control. Among the controls which should be provided by the completion procedure are control of gas, control of water, control for completion treatments, control for secondary recovery, control of work over costs, and control of expense during completion and subsequent production.

Engineering analysis and mature thought should be used in order to obtain the best possible completions.

Background

Oil was first found in West Texas approximately 30 years ago when almost all drilling was done with cable tools. Most of the early drilling was done on surface-indicated structures, and the pays found were shallow. The wells were drilled without fluid in the hole and, on many of the more prolific wells, the first indication of the pay zone was the sight of the tools blowing out of the hole.

Extensions to these fields were completed by setting pipe above the pay zone, and then drilling in with cable tools. Because many of the fields discovered early in the development of West Texas have very effective vertical and horizontal permeability, a well completed in them did not have to do much more than scratch the top of the pay in order to get at least fair drainage to the well bore. If the pay had a rather high pressure, it was often impossible to do much more than scratch the top of the pay before the well started producing. If the field had a natural gas cap, it was common practice to allow the well to blow gas to the air until the gas cap was dissipated and the well started making oil.

Logging on these wells was of the most elementary type and drillers' logs were often the only information that was available to show the productive zones. This caused many people to feel that there might not be drainage of any zones not left in open hole since they could not be certain of the location of these productive zones.
Secondary Recovery Operations in the Fullerton Clearfork Unit
Authors: Nolan W.E. , Locker G.R.
Published: June 2009

Introduction

Fullerton Field is located in northwestern Andrews County, Tex., and produces primarily from the lower Clearfork zone, an early Permian dolomite formation. The anticlinal structure has closure on two domes with the major axis of the structure extending in a general north-south direction. The commercial extent of the reservoir is determined by porosity pinch outs which do not follow the structural contours. The developed area of the North Dome covers 21,400 acres and is drilled on 40-acre spacing. The South Dome has a developed area of 3,700 acres and is also drilled on 40-acre spacing.

The field had an original static BHP of 2,980 psi, and the crude oil bubble point was 2,370 psi with 1,160 cu ft of gas per bbl being in solution. Early in the producing life of the field it was obvious that the solution gas drive mechanism would be relatively inefficient and the operators began to study the various means of unitizing and entering into a secondary recovery program.

Gas Injection Operations

In February. 1954, 24,040 surface acres of the field were unitized in order to instigate secondary recovery operations. Four months after unitization 16wells were converted to gas injection[See Fig. 1], and gas injection operations were initiated with a volume of approximately 21 MMcf/day or 30 per cent of the total gas production being returned to the reservoir. In September, 1956, four additional wells were converted to gas injection, and the injection volume was increased to 25 MMcf/day.

Fullerton Field operates under a limiting 2,000 cu ft/bbl gas-oil ratio. Gas which is returned to the reservoir is utilized in removing production penalties to the maximum of 66 bbl of oil per producing day per well. One of the immediate benefits of gas injection is to increase current allowable by production penalty removals.
The Role of Indigenous Microorganisms in the Biodegradation of Naturally Occurring Petroleum, the Reduction of Iron, and the Mobilization of Arsenite from West Bengal Aquifer Sediments
Authors: Rowland H. A. L. , Boothman C. , Pancost R. , Gault A. G. , Polya D. A. , Lloyd J. R.
Published: June 2009

High levels of naturally occurring arsenic are found in the shallow reducing aquifers of West Bengal, Bangladesh, and other areas of Southeast Asia. These aquifers are used extensively for drinking water and irrigation by the local population. Mechanisms for its release are unclear, although increasing evidence points to a microbial control. The type of organic matter present is of vital importance because it has a direct impact on the rate of microbial activity and on the amount of arsenic released into the ground water. The discovery of naturally occurring hydrocarbons in an arsenic‐rich aquifer from West Bengal provides a source of potential electron donors for this process. Using microcosm‐based techniques, seven sediments from a site containing naturally occurring hydrocarbons in West Bengal were incubated with synthetic ground water for 28 d under anaerobic conditions without the addition of an external electron donor. Arsenic release and Fe(III) reduction appeared to be microbially mediated, with variable rates of arsenic mobilization in comparison to Fe(III) reduction, suggesting that multiple processes are involved. All sediments showed a preferential loss of petroleum‐sourced n‐alkanes over terrestrially sourced sedimentary hydrocarbons n‐alkanes during the incubation, implying that the use of petroleum‐sourced n‐alkanes could support, directly or indirectly, microbial Fe(III) reduction. Samples undergoing maximal release of As(III) contained a significant population of Sulfurospirillum sp., a known As(V)‐reducing bacterium, providing the first evidence that such organisms may mediate arsenic release from West Bengali aquifers.
Effectiveness and Efficacy of Conservation Options after Potato Harvest
Authors: Griffin Timothy S. , Honeycutt C. W.
Published: June 2009

Soil erosion and phosphorus (P) runoff can be severe in potato production systems in the Northeast USA, which are characterized by intensive tillage, minimal ground cover, low crop residue return, and steep slopes. We used rainfall simulators in the greenhouse and field to assess sediment and P movement associated with two conservation practices: straw mulching and application of polyacrylamide (PAM). In the greenhouse, a Nokomis sandy loam soil (fine‐loamy, mixed, frigid Typic Haplorthods) was packed into 0.2 by 1.0 m boxes and subjected to four rainfall events at an intensity of 70 mm h−1 Runoff amount, sediment concentration, and inorganic and sediment‐bound P were measured for 30 min after initiation of runoff. Linear increases in straw mulch biomass (up to equivalent of 3000 kg ha−1) resulted in exponential decreases in sediment and P loss. Mulch applied at rates as low as 600 kg ha−1 provided nearly 50% ground cover and reduced sediment movement and sediment‐bound P concentration and loss by >50%. Higher application rates reduced sediment loss by up to 95% but contributed dissolved reactive P (DRP) to runoff water. Field observations using simulated rainfall on mulch‐covered and bare soil were consistent with greenhouse results. Linear increases in PAM application rate (to 20 kg ha−1) also reduced sediment loss. The efficacy of this practice decreases slightly with successive rainfall events but still had significant benefit through four simulated rainfalls on soil packed into boxes. This was not the case in the field where the effect of PAM was limited to the first two rainfall events. In general, runoff volume was not strongly influenced by any of these practices, and most of the P loss was comprised of sediment‐bound P. Both conservation practices are effective at reducing soil and nutrient loss in intensive potato systems.
Estimating Phosphorus Loss in Runoff from Manure and Fertilizer for a Phosphorus Loss Quantification Tool
Authors: Vadas P. A. , Good L. W. , Moore P. A. , Widman N.
Published: June 2009

Nonpoint‐source pollution of fresh waters by P is a concern because it contributes to accelerated eutrophication. Given the state of the science concerning agricultural P transport, a simple tool to quantify annual, field‐scale P loss is a realistic goal. We developed new methods to predict annual dissolved P loss in runoff from surface‐applied manures and fertilizers and validated the methods with data from 21 published field studies. We incorporated these manure and fertilizer P runoff loss methods into an annual, field‐scale P loss quantification tool that estimates dissolved and particulate P loss in runoff from soil, manure, fertilizer, and eroded sediment. We validated the P loss tool using independent data from 28 studies that monitored P loss in runoff from a variety of agricultural land uses for at least 1 yr. Results demonstrated (i) that our new methods to estimate P loss from surface manure and fertilizer are an improvement over methods used in existing Indexes, and (ii) that it was possible to reliably quantify annual dissolved, sediment, and total P loss in runoff using relatively simple methods and readily available inputs. Thus, a P loss quantification tool that does not require greater degrees of complexity or input data than existing P Indexes could accurately predict P loss across a variety of management and fertilization practices, soil types, climates, and geographic locations. However, estimates of runoff and erosion are still needed that are accurate to a level appropriate for the intended use of the quantification tool.
Transport of Lincomycin to Surface and Ground Water from Manure‐amended Cropland
Authors: Kuchta Sandra L. , Cessna Allan J. , Elliott Jane A. , Peru Kerry M. , Headley John V.
Published: June 2009

Livestock manure containing antimicrobials becomes a possible source of these compounds to surface and ground waters when applied to cropland as a nutrient source. The potential for transport of the veterinary antimicrobial lincomycin to surface waters via surface runoff and to leach to ground water was assessed by monitoring manure‐amended soil, simulated rainfall runoff, snowmelt runoff, and ground water over a 2‐yr period in Saskatchewan, Canada, after fall application of liquid swine manure to cropland. Liquid chromatography tandem mass spectrometry was used to quantify lincomycin in all matrix extracts. Initial concentrations in soil (46.3–117 μg kg−1) were not significantly different (p > 0.05) for manure application rates ranging from 60,000 to 95,000 L ha−1 and had decreased to nondetectable levels by mid‐summer the following year. After fall manure application, lincomycin was present in all simulated rainfall runoff (0.07–2.7 μg L−1) and all snowmelt runoff (0.038–3.2 μg L−1) samples. Concentrations in snowmelt runoff were not significantly different from those in simulated rainfall runoff the previous fall. On average, lincomycin concentrations in ephemeral wetlands dissipated by 50% after 31 d. Concentrations of lincomycin in ground water were generally <0.005 μg L−1 This study demonstrates that the management practice of using livestock manure from confined animal feeding operations as a plant nutrient source on cropland may result in antimicrobial transport to surface and ground waters.
Evaluating Nonpoint Source Critical Source Area Contributions at the Watershed Scale
Authors: White Michael J. , Storm Daniel E. , Busteed Philip R. , Stoodley Scott H. , Phillips Shannon J.
Published: June 2009

Areas with disproportionately high pollutant losses (i.e., critical source areas [CSAs]) have been widely recognized as priority areas for the control of nonpoint‐source pollution. The identification and evaluation of CSAs at the watershed scale allows state and federal programs to implement soil and water conservation measures where they are needed most. Despite many potential advantages, many state and federal conservation programs do not actively target CSAs. There is a lack of research identifying the total CSA pollutant contribution at the watershed scale, and there is no quantitative assessment of program effectiveness if CSAs are actively targeted. The purpose of this research was to identify and quantify sediment and total phosphorus loads originating from CSAs at the watershed scale using the Soil and Water Assessment Tool. This research is a synthesis of CSA targeting studies performed in six Oklahoma priority watersheds from 2001 to 2007 to aid the Oklahoma Conservation Commission in the prioritized placement of subsidized conservation measures. Within these six watersheds, 5% of the land area yielded 50% of sediment and 34% of the phosphorus load. In watersheds dominated by agriculture, the worst 5% of agricultural land contributed, on average, 22% of the total agricultural pollutant load. Pollutant loads from these agricultural CSAs were more than four times greater than the average load from agricultural areas within the watershed. Conservation practices implemented in these areas can be more effective because they have the opportunity to treat more pollutant. The evaluation of CSAs and prioritized implementation of conservation measures at the watershed scale has the potential to significantly improve the effectiveness of state and federally sponsored water quality programs.
Microbial Removal Rates in Subsurface Media Estimated From Published Studies of Field Experiments and Large Intact Soil Cores
Authors: Pang Liping
Published: June 2009

Information about the microbial removal efficiencies of subsurface media is essential for assessing the risk of water contamination, estimating setback distances between disposal fields and receiving waters, and selecting suitable sites for wastewater reclamation. By analyzing published data from field experiments and large intact soil cores, an extensive database of microbial removal rates was established for a wide range of subsurface media. High microbial removal rates were found in volcanic soils, pumice sand, fine sand, and highly weathered aquifer rocks. Low removal rates were found in structured clayey soils, stony soils, coarse gravel aquifers, fractured rocks, and karst limestones. Removal rates were lower for enteroviruses than for other human viruses; for MS2 phage than for other phage species; for waste‐associated microbes than for those cultivated in the laboratory; and for contaminated media than for uncontaminated media. Microbial removal rates are inversely correlated with infiltration rates and transport velocity. The assumption of first‐order law, or a constant removal rate (when the transport scale reaches a representative elementary volume), is appropriate for most of field data analyzed. However 30% of the datasets (26 out of 87 pairs) are better described with the power law, implying reduced removal rates with transport distance. The latter is most prominent for organically contaminated media, especially in relatively fine aquifer media. The presence of organic matter, heterogeneity in microbial properties, change in solution chemistry, detachment, and physical straining, may have caused the discrepancies from the first‐order law traditionally used in transport models for describing microbial removal.
Effects of Highway Construction on Stream Water Quality and Macroinvertebrate Condition in a Mid‐Atlantic Highlands Watershed, USA
Authors: Chen Yushun , Viadero Roger C. , Wei Xinchao , Fortney Ronald , Hedrick Lara B. , Welsh Stuart A. , Anderson James T. , Lin Lian‐Shin
Published: June 2009

Refining best management practices (BMPs) for future highway construction depends on a comprehensive understanding of environmental impacts from current construction methods. Based on a before‐after‐control impact (BACI) experimental design, long‐term stream monitoring (1997–2006) was conducted at upstream (as control, n = 3) and downstream (as impact, n = 6) sites in the Lost River watershed of the Mid‐Atlantic Highlands region, West Virginia. Monitoring data were analyzed to assess impacts of during and after highway construction on 15 water quality parameters and macroinvertebrate condition using the West Virginia stream condition index (WVSCI). Principal components analysis (PCA) identified regional primary water quality variances, and paired t tests and time series analysis detected seven highway construction‐impacted water quality parameters which were mainly associated with the second principal component. In particular, impacts on turbidity, total suspended solids, and total iron during construction, impacts on chloride and sulfate during and after construction, and impacts on acidity and nitrate after construction were observed at the downstream sites. The construction had statistically significant impacts on macroinvertebrate index scores (i.e., WVSCI) after construction, but did not change the overall good biological condition. Implementing BMPs that address those construction‐impacted water quality parameters can be an effective mitigation strategy for future highway construction in this highlands region.
Evaluation of Second‐Generation Multistage Wastewater Treatment System for the Removal of Malodors from Liquid Swine Waste
Authors: Loughrin John H. , Vanotti Matias B. , Szogi Ariel A. , Lovanh Nanh
Published: June 2009

Wastewater quality and malodors in a second generation implementation of environmentally superior technology (EST) were monitored over three cycles of pig (Sus scrofa) production and 15 mo. The wastewater treatment system consisted of three modules: solids separation, biological N removal, and P recovery/wastewater disinfection. While approximately more than 90% of the wastewater suspended solids were removed in the first stage of treatment, little reduction in malodorous compounds occurred, indicating that malodors largely remained with the liquid waste stream. The greatest improvements in wastewater quality occurred in the N treatment module where ammonium was removed through nitrification/denitrification processes: there was more than 99% reduction in aromatic malodorous compounds (e.g., p‐cresol, skatole) and almost 90% reduction in volatile fatty acids (e.g., propanoate and butanoate) in N module effluent as compared to raw flushed manure. The system performed consistently well in wastewater odor removal, even during the first cycle of livestock production when system performance was being optimized. These findings showed that the combination of the processes of solids removal and biological N treatment into a practical treatment system can be very effective in reducing malodors from livestock wastewater.
Barriers to Weight Management among Emirati Women: A Qualitative Investigation of Health Professionals' Perspectives
Authors: Ali Habiba I. , Bernsen Roos M. , Baynouna Latifa M.
Published: June 2009

Obesity and associated chronic diseases such as type 2 diabetes are highly prevalent in the United Arab Emirates. This qualitative study explored weight management barriers for Emirati women and strategies that can facilitate their weight management efforts. In-depth individual interviews were conducted with a purposive sample of 29 primary health care physicians, dietitians, and nurses in Al Ain and Abu Dhabi medical districts. A modified grounded theory was used to guide data collection and analysis. Interview notes were analyzed thematically and inductively using the NVivo software. The three main emerging themes were barriers, motivators, and suggestions. A number of personal, health care system-related, social and physical barriers to weight management were identified. Participants' suggestions to facilitate weight management for Emirati women included: health awareness programs, policies that support lifestyle changes, and provision of the necessary resources. They recommended peer support and culturally-acceptable programs that provide a holistic approach to obesity prevention and management. This study has useful applications in the development of community-based interventions for the prevention and management of overweight and obesity among women in the United Arab Emirates.
Sexual Behavior and Attitude toward Condoms among Unmarried ins-School and out-of-School Adolescents in a High-HIV Prevalence Region in Ghana
Authors: Sallar Anthony M.
Published: June 2009

Among adolescents in Africa and in the rest of the world, unprotected sexual intercourse is the primary cause of HIV transmission. There is limited information on population based study of adolescents who are not-in-school. A quantitative and qualitative study was conducted among adolescents aged 10–19 ( n = 483, mean age = 16.6) in the Ashanti region of Ghana on sexual behavior, condom use, and peer norms regarding sexuality. Age of sexual debut was younger for those in-school. However, out-of-school adolescents were more likely to ever have sexual intercourse (72.2% vs. 27.8%) and use condoms (83.6% vs. 16.4%) compared to their in-school counterparts. Religious affiliation was associated with being less sexually active. Statistically significant differences occurred for condom use and increased sexual activity with age. There is the need for programs to increase condom use. Adolescents in Ghana represent a vulnerable population and concerted efforts must be made to reach them.
The Settler's Ridge Site, an Early Woodland Leimbach Phase Upland Encampment in Northern Ohio
Authors: Keener Craig S. , Nye Kevin , Niedermier Joshua
Published: June 2009

In the summer of 2007 the Settler's Ridge site (33-AS-32), an Early Woodland upland encampment, was investigated through a series of cultural resource investigations. Excavations at the site suggest a single or limited occupation during the Early Woodland sometime between 569 to 624 B.C. The size of the site, depositional patterning of the artifacts, and feature outlay indicate a small sized encampment probably related to hunting activities in the uplands. This article summarizes the analysis of the lithic and ceramic assemblages, radiocarbon dates, site structure, and the depositional patterning evident at the site. Pottery recovered during excavations is Leimbach Cordmarked, which is representative of much of the northern Ohio area during the Early Woodland. Few Early Woodland upland sites in northern Ohio containing pottery have been intensively studied. Consequently, Settler's Ridge adds important information on how upland landforms were used during this period.
A Test for Maize Consumption by Fauna in Late Prehistoric Eastern North America
Authors: Ketchum Sheena A. , Schurr Mark R. , Garniewicz Rexford C.
Published: June 2009

It has been suggested that some animals eaten by late prehistoric populations of eastern North America were pest species that consumed maize. This could lead to over-estimates of amounts of maize that were directly consumed in prehistoric human diets. Stable carbon- and nitrogen-isotope ratios of collagen from white-tailed deer and raccoon bones from the Late Archaic Indian Knoll and Middle Mississippian Angel sites are compared. The stable isotope ratios are used to determine the amount of maize, if any, in Middle Mississippian faunal diets. We find no evidence that deer or raccoon at the Angel site consumed maize.
Prescribed Fire Effects on Wintering, Bark‐Foraging Birds in Northern Arizona
Authors: POPE THERESA L. , BLOCK WILLIAM M. , BEIER PAUL
Published: June 2009

ABSTRACT We examined effects of prescribed fire on 3 wintering, bark‐foraging birds, hairy woodpeckers (Picoides villosus), pygmy nuthatches (Sitta pygmaea), and white‐breasted nuthatches (S. carolinensis), in ponderosa pine (Pinus ponderosa) forests of northern Arizona, USA. During winters of 2004–2006, we compared bird density, foraging behavior, and bark beetle activity among burned treatment and unburned control units. Hairy woodpecker density was 5 times greater in burn units, whereas white‐breasted nuthatches and pygmy nuthatches had similar densities between treatments. Compared to available trees, trees used by foraging hairy woodpeckers had 9 times greater odds of having bark beetles in control units and 12 times greater odds in burn units. Tree diameter appeared to be the main factor bark‐foraging birds used in selecting winter foraging trees. Our results suggest that forest managers can use prescribed fire treatments without detrimental effects to wintering nuthatches, while providing additional food to hairy woodpeckers.
Effects and Mitigation of Road Impacts on Individual Movement Behavior of Wildcats
Authors: KLAR NINA , HERRMANN MATHIAS , KRAMER‐SCHADT STEPHANIE
Published: June 2009

ABSTRACT  Roads can affect the persistence of wildlife populations, through posing mortality risks and acting as barriers. In many countries, transportation agencies attempt to counterbalance these negative impacts. Road mortality is a major threat for European wildcats (Felis silvestris); therefore, we tested the effectiveness of a newly developed wildcat‐specific fence in preventing wildcat mortality along a new motorway. We hypothesized that such a fenced motorway would at the same time be a significant barrier to wildcats and may at worst result in 2 isolated populations. We used radiotracking data of 12 wildcats, resulting in 13,000 fixes, to investigate individual movement behavior during and after construction of a new motorway in southwestern Germany. The motorway was fenced with the wildcat‐specific fence and included crossing structures, not especially constructed for wildlife. Additionally we collected road kills on stretches of the same motorway with various types of fencing. A rate of 0.4 wildcat kills/km/year on the motorway, which was traveled by 10,000 vehicles/day and fenced with a regular wildlife fence, was reduced by 83% on stretches with wildcat‐specific fencing. Of the available crossing structures, wildcats preferred open‐span viaducts. Road underpasses were used but hold a mortality risk themselves. As opposed to our expectations, the fenced motorway (fenced with wildcat fence) posed only a moderate barrier to wildcats. Individuals were hindered in their daily routine and some stopped crossing completely but others continued crossing regularly. The adaptation of spatial and temporal behavior to traffic volume and location of crossing structures has an energetic cost. Hence, we suggest that only a small number of major roads can be tolerated within a wildcat's home range. To meet the demands of the European Habitats Directive, we recommend installing the wildcat fence in wildcat core areas along motorways to reduce wildcat mortality. We suggest that fences should incorporate safe crossing structures every 1.5‐2.5 km. Our findings in terms of fencing design and crossing structures can be used by transportation agencies for an effective reduction of road mortality and barrier effect for carnivores.
Fetal Sex Ratios in Southwestern Montana Elk
Authors: CUNNINGHAM JULIE A. , HAMLIN KENNETH L. , LEMKE THOMAS O.
Published: June 2009

ABSTRACT  The Trivers‐Willard (1973) model suggests maternal control of offspring sex, in utero or by the end of parental investment, may be an adaptive advantage in some species. We tested for differential sex allocation using 11,408 known‐sex fetal elk (Cervus elaphus) from biological collections and hunter harvest returns from 2 southwestern Montana, USA, elk populations (1961–2007). We included maternal and environmental condition covariates measured pre‐ and postconception and throughout pregnancy. Results suggested that adult female elk in southwest Montana did not differentially invest in male offspring when conditions were beneficial. We found evidence that, when the Northern Yellowstone elk herd was at low density, beneficial spring (May‐Jun) growing conditions, as indexed by a local precipitation measure and a regional drought indicator, correlated with production of more female fetuses (1 SD increase in precipitation and 1 SD decrease in drought resulted in 6% and 5% more F fetuses, respectively). In the same herd, we found evidence that improved maternal condition, as indexed by kidney fat mass and heart fat mass, also correlated with production of more female fetuses (1 SD increase in kidney fat mass and heart fat mass resulted in 8% more F fetuses). When the same elk herd reached higher densities under different ecological conditions, no covariate was associated with a deviation in the 50:50 female‐to‐male sex ratio. Similarly, there was no association between covariates and fetal sex ratios in a nearby elk herd at high population density. In modeling, wildlife managers should consider factors that could alter sex ratios at birth, and also how biased sex ratios postpartum could affect population models.
Evaluating Abundance Estimate Precision and the Assumptions of a Count‐Based Index for Small Mammals
Authors: WIEWEL ANDREW S. , ADAMS AMY A. YACKEL , RODDA GORDON H.
Published: June 2009

ABSTRACT  Conservation and management of small mammals requires reliable knowledge of population size. We investigated precision of mark‐recapture and removal abundance estimates generated from live‐trapping and snap‐trapping data collected at sites on Guam (n = 7), Rota (n = 4), Saipan (n = 5), and Tinian (n = 3), in the Mariana Islands. We also evaluated a common index, captures per unit effort (CPUE), as a predictor of abundance. In addition, we evaluated cost and time associated with implementing live‐trapping and snap‐trapping and compared species‐specific capture rates of selected live‐ and snap‐traps. For all species, mark‐recapture estimates were consistently more precise than removal estimates based on coefficients of variation and 95% confidence intervals. The predictive utility of CPUE was poor but improved with increasing sampling duration. Nonetheless, modeling of sampling data revealed that underlying assumptions critical to application of an index of abundance, such as constant capture probability across space, time, and individuals, were not met. Although snap‐trapping was cheaper and faster than live‐trapping, the time difference was negligible when site preparation time was considered. Rattus diardii spp. captures were greatest in Haguruma live‐traps (Standard Trading Co., Honolulu, HI) and Victor snap‐traps (Woodstream Corporation, Lititz, PA), whereas Suncus murinus and Mus musculus captures were greatest in Sherman live‐traps (H. B. Sherman Traps, Inc., Tallahassee, FL) and Museum Special snap‐traps (Woodstream Corporation). Although snap‐trapping and CPUE may have utility after validation against more rigorous methods, validation should occur across the full range of study conditions. Resources required for this level of validation would likely be better allocated towards implementing rigorous and robust methods.
Population Indices Versus Correlated Density Estimates of Black‐Footed Ferret Abundance
Authors: GRENIER MARTIN B. , BUSKIRK STEVEN W. , ANDERSON‐SPRECHER RICHARD
Published: June 2009

ABSTRACT  Estimating abundance of carnivore populations is problematic because individuals typically are elusive, nocturnal, and dispersed across the landscape. Rare or endangered carnivore populations are even more difficult to estimate because of small sample sizes. Considering behavioral ecology of the target species can drastically improve survey efficiency and effectiveness. Previously, abundance of the black‐footed ferret (Mustela nigripes) was monitored by spotlighting and generating indices of relative abundance because reintroduced populations were slow to establish. Indices, however, lack variance estimates and are costly to generate for the black‐footed ferret. We therefore used spotlight surveys and live‐trapping in conjunction with a robust mark‐recapture estimator to improve abundance monitoring for the black‐footed ferret, one of North America's most endangered carnivores. We estimated abundance of the black‐footed ferret at Shirley Basin, Wyoming, USA, using correlated density estimates and Program MARK. We compared our results to 2 indices of relative abundance, minimum number alive and predicted number of ferrets from litter counts. The correlated density estimate for the black‐footed ferret (N̂R = 229; 95% CI = 161–298) was similar to minimum number alive (N̂R = 192) and predicted number of ferrets from litter counts (N̂R= 235). The efficiency and effectiveness of survey methods we used for the black‐footed ferret were high by carnivoran standards. Our results suggest that the sampling approach we utilized can be implemented for a fraction of the cost and effort required to generate 2 indices of relative abundance for the black‐footed ferret. Although we recommend managers implement a similar survey approach to monitor abundance of reintroduced populations of the black‐footed ferret, analysis with sparse data sets will be problematic. Until the black‐footed ferret becomes widespread and abundant at a reintroduction site, spotlighting will remain preferable as a means to generate indices of distribution and relative abundance for the black‐footed ferret.
Roosts of Allen's Lappet‐Browed Bat in Northern Arizona
Authors: SOLVESKY BEN G. , CHAMBERS CAROL L.
Published: June 2009

ABSTRACT  In Arizona, USA, Allen's lappet‐browed bat (Idionycteris phyllotis) forms maternity colonies in ponderosa pine (Pinus ponderosa) snags. There is little information on the roosting habitat of males. We used radiotelemetry to locate 16 maternity, 3 postlactating, and 2 bachelor roosts and combined data with unpublished data for maternity roosts (n = 11) located in 1993–1995. Most (96%) maternity roosts were in large‐diameter (x̄ ± SE: 64 ± 2.7 cm) ponderosa pine snags under sloughing bark. Models that best predicted the probability of a snag's use as a maternity roost indicated bats selected taller snags closer to forest roads than comparison snags. Maternity roosts averaged 11 bats per roost (SE = 2, n = 15; from exit counts) and were an average distance of 1.6 km from capture sites (SE = 0.3, n = 17). Bachelor roosts were in vertical sandstone cliff faces in pinyon‐juniper (Pinus edulis‐Juniperus spp.) woodlands approximately 12 km from capture sites; these and other capture records in Arizona indicated sexual segregation may have occurred during the maternity season. Of 11 maternity snag roosts located in 1993–1995, only one continued to function as a roost. Resource managers should maintain patches of large‐diameter ponderosa pine snags with peeling bark to provide maternity roosting habitat for Allen's lappet‐browed bat.
Deer Forage Response to Herbicide and Fire in Mid‐Rotation Pine Plantations
Authors: MIXON MELINDA R. , DEMARAIS STEPHEN , JONES PHILLIP D. , RUDE BRIAN J.
Published: June 2009

ABSTRACT  Mid‐rotation management practices for pine (Pinus spp.) plantations enrolled in cost‐share programs have not been widely evaluated for wildlife. Mid‐rotation pine plantations often have a substantial hardwood mid‐story that limits growth of desirable understory forage species important to white‐tailed deer (Odocoileus virginianus; deer). We treated with imazapyr herbicide and prescribed burning (HB) 11 thinned, 13–22‐year‐old loblolly pine (P. taeda) plantations in the Upper Coastal Plain (UCP; n = 5) and the Lower Coastal Plain (LCP; n = 6) of Mississippi, USA, enrolled in cost‐share programs. We then sampled these plantations for production of important deer forages during July of 2003 and 2004, years 1 and 2 posttreatment. Deer foraging habitat was clearly improved by the HB treatment in both regions by year 2. Forb species of annual importance to deer increased in percent cover and biomass in the UCP and in biomass in the LCP. We estimated nutritional carrying capacity using a target diet quality of 14% crude protein; estimates in HB plots were 3 times greater than controls in the UCP and 19 times greater in the LCP. Although UCP sites had baseline carrying capacities nearly 8 times greater than LCP sites, the greater relative response to HB in the LCP eliminated the regional difference. Our results indicate that imazapyr herbicide treatment followed by prescribed fire is a beneficial tool for deer management in mid‐rotation pine plantations.
Light curve analysis of the late type binary V523 Cassiopeiae
Authors: Latkovic O. , Zboril M. , Djurasevic G.
Published: June 2009

We present the analysis of V and R light curves of the late type contact binary V523 Cas for the season of 2006. These observations make part of the monitoring program aimed at studying the long-term light curve variability in this system. Our results confirm that the system is in an over contact configuration, and include a bright spot in the neck region of the cooler and larger primary. We compare these results with the previous solution, obtained for the season 2005 dataset and discuss the differences.
The 100 strongest radio point sources in the field of the Large Magellanic Cloud at 1.4 GHz
Authors: Payne J.L. , Tauber L.A. , Filipovic M.D. , Crawford E.J. , de Horta
Published: June 2009

We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC). The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA) over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (?) of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.
Insulin Granule Recruitment and Exocytosis Is Dependent on p110γ in Insulinoma and Human β-Cells
Authors: Pigeau Gary M. , Kolic Jelena , Ball Brandon J. , Hoppa Michael B. , Wang Ying W. , Rückle Thomas , Woo Minna , Manning Fox Jocelyn E. , MacDonald Patrick E.
Published: June 2009

OBJECTIVE

Phosphatidylinositol 3-OH kinase (PI3K) has a long-recognized role in β-cell mass regulation and gene transcription and is implicated in the modulation of insulin secretion. The role of nontyrosine kinase receptor–activated PI3K isoforms is largely unexplored. We therefore investigated the role of the G-protein–coupled PI3Kγ and its catalytic subunit p110γ in the regulation of insulin granule recruitment and exocytosis.

RESEARCH DESIGN AND METHODS

The expression of p110γ was knocked down by small-interfering RNA, and p110γ activity was selectively inhibited with AS605240 (40 nmol/l). Exocytosis and granule recruitment was monitored by islet perifusion, whole-cell capacitance, total internal reflection fluorescence microscopy, and electron microscopy in INS-1 and human β-cells. Cortical F-actin was examined in INS-1 cells and human islets and in mouse β-cells lacking the phosphatase and tensin homolog (PTEN).

RESULTS

Knockdown or inhibition of p110γ markedly blunted depolarization-induced insulin secretion and exocytosis and ablated the exocytotic response to direct Ca2+ infusion. This resulted from reduced granule localization to the plasma membrane and was associated with increased cortical F-actin. Inhibition of p110γ had no effect on F-actin in β-cells lacking PTEN. Finally, the effect of p110γ inhibition on granule localization and exocytosis could be rapidly reversed by agents that promote actin depolymerization.

CONCLUSIONS

The G-protein–coupled PI3Kγ is an important determinant of secretory granule trafficking to the plasma membrane, at least in part through the negative regulation of cortical F-actin. Thus, p110γ activity plays an important role in maintaining a membrane-docked, readily releasable pool of secretory granules in insulinoma and human β-cells.
Effects of Salt Supplementation on the Albuminuric Response to Telmisartan With or Without Hydrochlorothiazide Therapy in Hypertensive Patients With Type 2 Diabetes Are Modulated by Habitual Dietary Salt Intake
Authors: Ekinci Elif I. , Thomas Georgina , Thomas David , Johnson Cameron , MacIsaac Richard J. , Houlihan Christine A. , Finch Sue , Panagiotopoulos Sianna , O'Callaghan Chris , Jerums George
Published: June 2009

OBJECTIVE

This prospective randomized double-blind placebo-controlled crossover study examined the effects of sodium chloride (NaCl) supplementation on the antialbuminuric action of telmisartan with or without hydrochlorothiazide (HCT) in hypertensive patients with type 2 diabetes, increased albumin excretion rate (AER), and habitual low dietary salt intake (LDS; <100 mmol sodium/24 h on two of three consecutive occasions) or high dietary salt intake (HDS; >200 mmol sodium/24 h on two of three consecutive occasions).

RESEARCH DESIGN AND METHODS

Following a washout period, subjects (n = 32) received 40 mg/day telmisartan for 4 weeks followed by 40 mg telmisartan plus 12.5 mg/day HCT for 4 weeks. For the last 2 weeks of each treatment period, patients received either 100 mmol/day NaCl or placebo capsules. After a second washout, the regimen was repeated with supplements in reverse order. AER and ambulatory blood pressure were measured at weeks 0, 4, 8, 14, 18, and 22.

RESULTS

In LDS, NaCl supplementation reduced the anti-albuminuric effect of telmisartan with or without HCT from 42.3% (placebo) to 9.5% (P = 0.004). By contrast, in HDS, NaCl supplementation did not reduce the AER response to telmisartan with or without HCT (placebo 30.9%, NaCl 28.1%, P = 0.7). Changes in AER were independent of changes in blood pressure.

CONCLUSIONS

The AER response to telmisartan with or without HCT under habitual low salt intake can be blunted by NaCl supplementation. By contrast, when there is already a suppressed renin angiotensin aldosterone system under habitual high dietary salt intake, the additional NaCl does not alter the AER response.
Effect of Glucose Variability on the Long-Term Risk of Microvascular Complications in Type 1 Diabetes
Authors: Kilpatrick Eric S. , Rigby Alan S. , Atkin Stephen L.
Published: June 2009

OBJECTIVE

This study analyzed data from the Epidemiology of Diabetes Interventions and Complications (EDIC) study to see whether longer-term follow-up of Diabetes Control and Complications Trial (DCCT) patients reveals a role for glycemic instability in the development of microvascular complications.

RESEARCH DESIGN AND METHODS

The mean area under the curve glucose and the within-day glucose variability (SD and mean amplitude of glycemic excursions [MAGE]) during the DCCT were assessed to see whether they contributed to the risk of retinopathy and nephropathy by year 4 of the EDIC.

RESULTS

Logistic regression analysis showed that mean glucose during the DCCT and mean A1C during EDIC were independently predictive of retinopathy (each P < 0.001) as well as A1C during EDIC of nephropathy (P = 0.001) development by EDIC year 4. Glucose variability did not add to this (all P > 0.25 using SD or MAGE).

CONCLUSIONS

Glucose variability in the DCCT did not predict the development of retinopathy or nephropathy by EDIC year 4.
First-Trimester Fasting Hyperglycemia and Adverse Pregnancy Outcomes
Authors: Riskin-Mashiah Shlomit , Younes Grace , Damti Amit , Auslender Ron
Published: June 2009

OBJECTIVE

The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study found strong associations between higher levels of maternal glucose at 24–32 weeks, within what is currently considered normoglycemia and adverse pregnancy outcomes. Our aim was to evaluate the associations between first-trimester fasting plasma glucose level and adverse pregnancy outcomes.

RESEARCH DESIGN AND METHODS

Charts of all patients who delivered at our hospital between June 2001 and June 2006 were reviewed. Only subjects with singleton pregnancy and a recorded first-trimester fasting glucose level were included. Women with pregestational diabetes, fasting glucose level >105 mg/dl, or delivery <24 weeks were excluded. Fasting glucose levels were analyzed in seven categories, similar to the HAPO study. The main outcomes were development of gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates and/or macrosomia, and primary cesarean section. Multivariate logistic regression analysis was used; significance was <0.05.

RESULTS

A total of 6,129 women had a fasting glucose test at median of 9.5 weeks. There were strong, graded associations between fasting glucose level and primary outcomes. The frequency of GDM development increased from 1.0% in the lowest glucose category to 11.7% in the highest (adjusted odds ratio 11.92 [95% CI 5.39–26.37]). The frequency of LGA neonates and/or macrosomia increased from 7.9 to 19.4% (2.82 [1.67–4.76]). Primary cesarean section rate increased from 12.7 to 20.0% (1.94 [1.11–3.41]).

CONCLUSIONS

Higher first-trimester fasting glucose levels, within what is currently considered a nondiabetic range, increase the risk of adverse pregnancy outcomes. Early detection and treatment of women at high risk for these complications might improve pregnancy outcome.