bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in Wireline Conveyed In-situ Reservoir Stress Testing Measurements: Case Studies from the Sultanate of Oman
Authors: Cig Koksal , Al Mandhari Alyaqdhan Sulaiman , El Msallati Salem Mohammed , Qobi Latifa
Published: December 2009

In-situ reservoir stress measurements are essential input to a wide variety of the production and injection applications of reservoirs.Most of the reservoirs in this article require water injection to maximize recovery without breaking the matrices unintentionally. In some cases,it is also important to create a controlled fracture growth in a formation unit without breaking bordering barriers or zones.The main purpose of the in-situ reservoir stress testing of the case studies in this article is to calculate the minimum stress to improve the reservoir management plans for well placement, production,injection and fracturing processes.

One approach of measuring stresses in many zones is to use the wireline conveyed stress testing tools. The wireline conveyed in-situ reservoir stress testing measurements are frequently performed in the Sultanate of Oman for a wide range of operational and geomechanics applications such as but not limited to: Hydraulic fracturingFracture growth/containment issuesPolymer injectionBorehole stabilitySand production predictionStress evolution with depletion, hot and cold injection

The stress testing zones vary from tight to high permeable zones as well as shale zones. The complexity and wide variety of the stress testing applications inevitably led modifications and improvements on the wireline conveyed stress testing tools. These improvements mainly are various types of pumps, higher performance dual packers and mandrels, innovative stress testing methods. The latest improvements and methods in stress testing help addressing the broader range of formations (deep and shallow,tight and permeable) in an extensive type of wells from vertical or deviated to horizontal.

In this article, the examples of several unique stress testing applications are presented. Shale stress testing with a viscous fluid, horizontal well stress testing,tight and very high permeability formation stress testing, sleeve fracturing stress testing methods are discussed in details.
Closing the Loop between Volumetric and Material Balance Estimates - Naturally Fractured Carbonates
Authors: Aziz Rafi Mohammad , Dashti Qasem , Manoch Limsukhon , Ghorayeb Kassem , Chakraborty Subrata , Liu Hai
Published: December 2009

This paper shows a systematic approach to reduce uncertainty of volume, recovery factors and production forecasts with a closed loop of static and dynamic information over the life of the reservoirs. A case study of a Middle Marrat reservoir block in the North Kuwait Jurassic Complex (NKJC) is presented to illustrate the procedures. The NKJC comprises of six discovered fields each consisting of at least four prospective producing units containing multiple fluid types at near critical conditions. Intra-field compartmentalization due to fracture intensity, faulting and litho-facies variations resulting in porosity / permeability pinch outs has further created isolated blocks with a high level of uncertainty in the reservoir parameters describing the storage and flow characteristics necessary for forecasting well behaviors resulting from connected volumes. It is vital to collect as much dynamic data as possible at an early stage of the development for reserve booking and production forecast. Field development plan envisaged for the NKJC considered a three-phase development in order to mitigate CAPEX risk, reduce uncertainty and optimize recovery. Each phase has sufficient gap (3-4 years) to drill wells, collect formation evaluation and well performance data and adjust future plans as necessary. This paper describes the building blocks of volumetric estimates and fluid flow characteristics, considering the uncertainty levels in litho-facies spreads, porosity / permeability relationships, water saturations and fracture geometries etc. based on initial drilling and limited well tests. After the start of production, fluid properties monitoring, collection of well surveillance data such as pressure vs. rate curves, pressure transient analysis (PTA), production logging surveys (PLT), Modular Formation Dynamics Tester (MDT) and material balance calculations indicate another set of storage and flow properties. Integrating these estimates with geology, structural framework and fracture geometry is the key to obtaining a consistent reservoir description. Consistency in turn, reduces uncertainty in the connected volumes and flow dynamics over time. Flow assurance calculations using simulation model calibrated with the integrated set of parameters have been made with confidence to support a lifecycle reservoir management strategy to optimize recovery.

Case study illustrates that Green Field development plans benefit greatly from early dynamic data collection integrated with volumetric estimations by reducing uncertainty of reservoir description parameters that are used to calculate in-place hydrocarbon volumes and reserves. Reservoir uncertainty in naturally fractured carbonates is maximum with consequent risks. The methodology and work flow thus generated may be repeated for other blocks in the complex and for similar naturally fractured reservoirs.
Fracture Geometry Characterizations through Physical Modeling
Authors: Al-Bazzaz W. H. , Al-Tarkait F. , Ali A. , Al-Attar M.
Published: December 2009

Fractures have been known to exist in reservoirs for the last half century, yet the practice of characterizing fractured rock reservoir system has been extremely slow. Why is this so? The greatest contributor to this point of view is that fractured reservoirs are extremely complex. The complexity is attributed to vast number of both dependant and independent geometrical variables that dictates final reservoir response.

Fracture characterization is essential step to understand the overall reservoir performance, and to accomplish this, it is imperative to integrate all facets of information to achieve optimization of permeability response. A basic physics-understanding is absent of the fracture morphology that commonly occur in naturally fractured-reservoirs (NFR). This knowledge will help understand flow and recovery patterns in fractured reservoirs. For example, fracture-population and fracture-spacing, fracture area (length & width), fracture opening (fracture-porosity), and fracture-orientation. The model will simulate several scenarios of hypothetical fracture geometries in pursue of overall reservoir permeability. Anyone who has dealt with natural fractured reservoirs will realize that these variables are few of other numerous variables that when combined properly would have a better prediction for the reservoir overall performance.

Systematic fractured reservoir physical-models are proposed for this study. It is known that almost all fractured reservoirs respond in a unique way according to the class of their fracture. Therefore, the principal objective of the study is to construct a physical model of an artificial permeable reservoir that will host many sets of controlled fracture geometry and morphology. These fractures will be designed and tested. Further these fractures will be studied and modeled in order to seek fundamental knowledge of their impact on total reservoir performance.
Digital Photography Improves Consistency and Accuracy of Bat Counts in Hibernacula
Authors: MERETSKY VICKY J. , BRACK VIRGIL , CARTER TIMOTHY C. , CLAWSON RICHARD , CURRIE ROBERT R. , HEMBERGER TRACI A. , HERZOG CARL J. , HICKS ALAN C. , KATH JOSEPH A. , MACGREGOR JOHN R. , KING R. ANDREW , GOOD DAVID H.
Published: December 2009

ABSTRACT The size and distribution of measurement errors associated with major techniques for estimating numbers of hibernating bats are unstudied, although this is the principle method of enumerating several endangered bat species. However, decisions concerning the listing status of a species under the Endangered Species Act require consistent and accurate estimation of population size and trends. Recent advances in digital photography have improved the ability to produce a quantitative record of the numbers of bats in hibernacula. We surveyed clusters of Indiana bats in a hibernaculum and compared results from counts of digital photographs of clusters to results from 4 variations of visual estimation. We counted bats in photographs using Geographic Information System digitization over the photograph. Total counts from 2 sets of photographs varied by <1.5%. Nonphotographic estimation techniques varied from 76% to 142% of counts from photographs for clusters for which estimation (rather than counting) was used. Where feasible, photography can improve status and trend information for species of concern, permitting more timely and specific management actions.
Effects of Mesopredators on Nest Survival of Shrub‐Nesting Songbirds
Authors: CONNER L. MIKE , RUTLEDGE JESSICA C. , SMITH LORA L.
Published: December 2009

ABSTRACT  Although nest predation is often the single largest source of mortality in avian populations, manipulative studies to determine predator impacts on nest survival are rare, particularly studies that examine impacts of mid‐size mammalian predators (hereafter, mesopredators) on nest survival of shrub‐nesting birds. We quantified nest survival and identified nest predators of shrub‐nesting songbirds within 4 large (approx. 40‐ha) exclosures and 4 control sites within a longleaf pine (Pinus palustris) ecosystem. During 2003–2006, we located and monitored 535 shrub nests (222 with videography) for 4,804 nest‐days to quantify daily nest survival and document predation events. We found no support for a treatment effect, suggesting mesopredators had little impact on daily nest survival (0.9303 in controls and 0.9260 in exclosures) of shrub‐nesting songbirds. For the 5 most commonly monitored species, daily nest survival within species was constant. Our analysis suggested that shrub nests were most vulnerable during the nestling stage and presence of cameras on nests increased survival with the increase in survival being more pronounced during the incubation stage. We filmed 107 nest predation events, identifying predators at 88 nests. Of these 88 nests, snakes caused 33%, red imported fire ants (hereafter fire ants, Solenopsis invicta) 28%, raptors 17%, corvids 8%, mesopredators 6%, and small mammals 8% of nest predations. Cause‐specific nest predation in controls and exclosures did not differ from expectation, providing evidence that compensatory predation did not occur. Nest predators differed from expectation with regard to nest stage; fire ants and raptors only depredated nests during the nestling stage. Presence of cameras had no effect on nest abandonment. Fire ants were the most prevalent nest predator, and nest predation by fire ants was only observed on nestlings, potentially reducing likelihood of renesting. Magnitude and timing of fire ant predation suggests that fire ants may be the most influential nest predator of shrub‐nesting birds within the longleaf pine ecosystem. Our data suggest that controlling mesopredators will have no effect on nest success of shrub‐nesting birds within longleaf pine forests.
Habitat and Landscape Effects on Brood Parasitism, Nest Survival, and Fledgling Production in Swainson's Warblers
Authors: BENSON THOMAS J. , ANICH NICHOLAS M. , BROWN JEREMY D. , BEDNARZ JAMES C.
Published: December 2009

ABSTRACT Numerous factors, including nest predation and brood parasitism, may limit populations of neotropical migratory birds. However, nest predation and brood parasitism are not constant, and temporal, biological, habitat, and landscape factors can affect the likelihood of these events. Understanding these patterns is important for species of conservation concern for which managers seek to provide quality habitat. One such species, the Swainson's warbler (Limnothlypis swainsonii), is a neotropical migrant that breeds primarily in bottomland hardwood forests of the southeastern United States. Little is known of factors influencing reproductive success of this rare, yet locally abundant, species. From 2004 through 2007, we examined factors influencing reproductive success of Swainson's warblers at 2 sites in eastern Arkansas, USA, St. Francis National Forest and White River National Wildlife Refuge. We used 2‐stage modeling to assess the relationship between 1) temporal and biological, and 2) habitat and landscape factors and brood parasitism, nest survival, and fledgling production. Brood parasitism was greater in this population (36%) than reported elsewhere (≤ 10%), but decreased throughout the breeding season. Nest survival was comparable to or lower than in other populations of this species and increased throughout the breeding season. The probability of brood parasitism was greater near forest edges. Although nests of Swainson's warblers were often associated with giant cane (Arundinaria gigantea), nest survival had a weak negative association with cane density. For nests that were successful, the best predictor of number of Swainson's warblers fledged was brood‐parasitism status: nonparasitized nests fledged 2.75 young, whereas parasitized nests fledged 0.60 Swainson's warblers. Our findings suggest that managing and restoring relatively high‐elevation bottomland forests that are located far from agricultural edges should increase Swainson's warbler productivity.
Use of Forest Edges by Bats in a Managed Pine Forest Landscape
Authors: MORRIS ADAM D. , MILLER DARREN A. , KALCOUNIS‐RUEPPELL MATINA C.
Published: December 2009

ABSTRACT  Forest edges often have increased species richness and abundance (edge effect) and affect spatial behaviors of species and dynamics of species interactions. Landscapes of intensively managed pine (Pinus spp.) stands are characterized by a mosaic of patches and linear forest edges. Managed pine forests are a primary landscape feature of the southeastern United States, but the effects of intensive management on bat communities are poorly understood. Insectivorous bats are important top predators in nocturnal forest food webs. We examined bat foraging behavior along forest edges and in 4 structurally distinct stand types (open‐canopy pine, prethinned pine, thinned pine, and unmanaged forest) within a managed pine forest in the coastal plain of North Carolina, USA. During May‐August, 2006 and 2007, we recorded echolocation calls using Pettersson D240X bat detectors linked to digital recorders at 156 sites. We also sampled nocturnal flying insects at each site using Malaise insect traps. We used negative binomial count regression models to describe bat foraging behavior relative to forest edges, stand types, and prey availability. Although some species showed affinities for certain stand types and prey items, bat activity patterns were most strongly related to forest edges. Edges were used extensively by 6 aerial‐hunting bat species, but avoided by Myotis species. Forest edges function similarly to natural forest gaps, by providing foraging opportunities for aerial‐hunting bat species. Therefore, the maintenance of forest edges in managed pine landscapes may enhance foraging habitat for aerial‐hunting bat species.
Factors Related to Preferences for Trap‐Neuter–Release Management of Feral Cats Among Illinois Homeowners
Authors: LOYD KERRIE ANNE , MILLER CRAIG A.
Published: December 2009

ABSTRACT  Populations of feral domestic cats have increased throughout the United States, affecting wildlife and warranting attention from a variety of management agencies. This contentious issue requires a greater understanding of public attitudes and preferences for population control. We used data from a 2004 mail survey of Illinois, USA, homeowners’ attitudes towards wildlife and conservation to investigate support for the trap‐neuter–release (TNR) of feral cats and to examine factors (demographic, experience, and wildlife values orientations) that may influence preference for TNR as a management option. Age, gender, and wildlife rights values orientations were significant predictors of preference for TNR, while negative experiences with feral cats were correlated with preferences for management options other than TNR. Investigations of public perceptions of feral cat management can help wildlife managers understand the growing public debate regarding feral cat management and provide appropriate input and educational materials regarding cat management and wildlife.
Brown Bear Den Habitat and Winter Recreation in South‐Central Alaska
Authors: GOLDSTEIN MICHAEL I. , POE AARON J. , SURING LOWELL H. , NIELSON RYAN M. , MCDONALD TRENT L.
Published: December 2009

ABSTRACT Increasing demand for backcountry recreation opportunities during winter (e.g., snowshoeing, helicopter‐assisted skiing, snowmobiling) in steep, high‐elevation terrain has elevated concern about disturbance to brown bears (Ursus arctos) denning on the Kenai Peninsula, Alaska, USA. To help identify areas where such conflicts might occur, we developed a spatially explicit model to predict potential den habitat. The model indicated brown bears selected locations for den sites with steep slopes, away from roads and trails. Den sites were associated with habitat high in elevation and away from potential human contact. We then compared areas with the highest probability of providing den habitat with patterns of snowmobile and nonmotorized recreation on a portion of the Kenai Peninsula. We found limited overlap between the 2 recreation activities and potential den habitat for brown bears. At the landscape scale, however, backcountry skiing overlapped more high‐quality den habitat than did snowmobile riding. Our results may be used by land management agencies to identify potential conflict sites and to minimize the potential effects of recreation activities on brown bears in dens.
Monitoring Golden‐Cheeked Warblers on Private Lands in Texas
Authors: COLLIER BRET A. , MORRISON MICHAEL L. , FARRELL SHANNON L. , CAMPOMIZZI ANDREW J. , BUTCHER JERROD A. , HAYS K. BRIAN , MACKENZIE DARRYL I. , WILKINS R. NEAL
Published: December 2009

ABSTRACT A majority of North American breeding habitat for neotropical migrants exists on private lands, requiring monitoring strategies focused on habitat in these private holdings. We outline study designs and protocols using repeated Presence‐Absence surveys across a gradient of patch sizes to develop a range‐wide monitoring program for the endangered golden‐cheeked warbler (Dendroica chrysoparia) in Texas, USA. We surveyed 200–400 point‐count locations across approximately 30 private properties annually from 2005 to 2008. We used data from our surveyed patches (n= 147) and the Ψ (occupancy), p (detection), and γ = 1 ‐ ɛ parameterization to estimate patch dynamics and associated detection probabilities for golden‐cheeked warblers. Patch size had a strong association with patch occupancy, and all patches >160 ha were predicted to be occupied. We found no evidence that large golden‐cheeked warbler populations located on public lands in the vicinity of our study area influenced occupancy dynamics. We conducted simulations across a range of detection probabilities to evaluate potential sample sizes for both standard‐ and removal‐based occupancy modeling. Simulations using parameter estimates from our analysis indicated that removal‐based sampling is superior to standard sampling. Based on our results, surveying golden‐cheeked warbler presence in oak‐juniper (Quercus‐Juniperus) patches under a removal modeling framework should be considered as one alternative for range‐wide monitoring programs because patch‐level monitoring would be necessary to estimate proportion of range occupied. Large contiguous patches are rare across the species’ range; hence, conservation and management of the mosaic of smaller patches within a landscape context would be required for maintaining species viability. Thus, we recommend the identification of areas where smaller, contiguous patches represent a significant portion of the available habitat within the local landscape and targeting these areas for habitat maintenance and improvement.
Carbon Tax: The French Connection
Authors: Laurent Éloi
Published: December 2009

In early 2010, France will introduce a carbon tax, becoming the largest economy in the world to do so. According to Éloi Laurent, the introduction of a carbon tax in France is a good example that ecologically efficient and socially fair solutions do exist to curb climate change, but that it takes public pedagogy, sound economic reasoning and above all political courage to bring them into being.
Evolutionary programmed development as the basis of Darwinian selection: A review
Authors: Marinkovic D.
Published: December 2009

The sources of biological variation are numerous and versatile. The basic problem is to explain how this huge potential variation could be limited and reduced to adaptive combinations of allelogenes and characters. It has been estimated that, in a population of Drosophila melanogaster with a few thousands of individuals, the number of existing genotypes for a metabolic system controlled by 8-10 polymorphic loci, would not exceed more than 0.5% of possible combinations of genes. Based on individual allozyme analysis of such a system in 400 flies, less than 1 pro-mile of possible combinations of three largest chromosomes of this species could be present in spermatozoa of an adult male, before they enter a competition to produce viable zygotes. Such adaptive combinations are targets of natural selection, realized through a restricted number of developmental (metabolic) programmes, being also the units of inheritance. The basic role in evolutionary development of such systems have intrinsic factors, i.e., the rules of auto-synthesis of well established programmes, directing a restrictive variation of adaptive variants with which Darwinian selection can operate.
Comparison of two sample preparation procedures for HPLC determination of ochratoxin A
Authors: Vukovic Gorica , Pavlovic Snezana , Ristic M.S.
Published: December 2009

In preparation of samples for chromatographic determination of ochratoxin A, two types of columns were used for sample cleanup (SPE and immunoaffinity columns). The first method consisted of liquid-liquid extraction with a mixture of chloroform and phosphoric acid, followed by ion-exchange cleanup on Waters Oasis MAX columns. The sec?ond method consisted of extraction with a mixture of water and methanol, followed by LCTech OtaCLEAN immunoaf?finity column cleanup. Recoveries of the methods were determined at three levels in three repetitions for maize flour, and they were 84% (%RSD = 19.2) for the first method of sample preparation and 101% (%RSD = 2.2) for the second method. Values of LOQ for OTA were 0.25 and 1.00 ?g/kg for the IAC and SPE clean-up procedures, respectively. Both methods comply with present regulations, but the MAX sample clean-up procedure should be used as an alternative, since the immunoaffinity column clean-up procedure is characterized by better reproducibility, accuracy, and efficiency.
The anterior cingulate cortex
Authors: Pavlovic D.M. , Pavlovic Aleksandra , Lackovic Maja
Published: December 2009

The anterior cingulate cortex (ACC) has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision). Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.
Esterase variation in Turkish white-toothed shrews (Crocidura): Record of a trimeric esterase
Authors: Tez C. , Özcan S. , Gündüz İ. , Haskiliç Ş. , İbiş O. , Toprak G.
Published: December 2009

This study focuses on esterase variation of the genus Crocidura in Turkey. A total of 248 white-toothed shrews were analyzed by means of cellulose acetate gel electrophoresis. Liver tissue and alfa naphthyl acetate were used to investigate esterase variation in Turkish white-toothed shrews. A different esterase banding pattern was found in one Crocidura individual. This phenotype had four anodally migrated bands on cellulose acetate gel. The Crocidura individual displaying the given phenotype was identified as Crocidura suaveolens. The different esterase banding pattern observed in this study is considered to be a result of the trimeric structure of esterase in the lesser white-toothed shrew (Crocidura suaveolens).
Basic indices of spleen immune activity in natural populations of Norway rats (Rattus norvegicus berkenhout, 1769) in Serbia
Authors: Kataranovski Milena , Mirkov Ivana , Zolotarevski Lidija , Popov Aleksandra , Belij Sandra , Stosic Jelena , Kataranovski D.
Published: December 2009

Basic parameters of spleen immune activity (spleen weight, histomorphology of splenic compartments, and mitogen-induced splenocyte proliferative capacity in vitro) were evaluated in adult individuals of wild Norway rats from urban habitats and compared to the same data obtained in laboratory rat strains. A wider range of relative spleen mass and differential histomorphological characteristics, together with differences in the level and pattern of responsiveness of splenocytes to exogenous stimulation, were noted in spleens of wild Norway rats. Evidence of both enhanced and low-level immune-relevant spleen activity in wild rats demonstrates the complexity of changes in spleen immune activity in rats from natural populations.
Effects of spirodiclofen on the reproductive potential of two-spotted spider mite (Acari: Tetranychidae) ovipositing females
Authors: Marcic D. , Ogurlic Irena , Peric P.
Published: December 2009

A laboratory bioassay was conducted to evaluate the effects of spirodiclofen on the survival and reproduction of young and mated females of two-spotted spider mite (Tetranychus urticae Koch). The females were sprayed with a series of acaricide concentrations (96, 48, 24, 12, and 6 mg/l) 24-30 h after adult emergence, i.e., at the age most likely to exhibit dispersal behavior and close to their reproductive maximum. The proportions of T. urticae females that survived treatment without symptoms of poisoning were concentration-dependent, ranging between 0.41 and 0.88 (0.96 in the control). With the exception of females that survived 6 mg/l, fecundity of the treated female mites was strongly affected during the exposure, compared to the control. The mean daily fecundity (EL) and mean daily fertility (EH) of surviving females, transferred daily to new leaf disks over the following five days, significantly decreased as spirodiclofen concentrations increased. In treatments with 6 mg/l and 12 mg/l, only the latter concentration significantly reduced both EL and EH, compared to the control. In females that survived 24 mg/l and 48 mg/l, these life history parameters were reduced by over 90%, while treatment with 96 mg/l completely terminated egg-laying. The treated females lived for a significantly shorter time than untreated ones, with the exception of females that survived 6 mg/l. Compared to the control females, gross fecundity (GL) and gross fertility (GH) of the treated females were strongly reduced on the first and second day; from the third day onward, females treated with the lowest concentrations achieved marked recovery, their GL and GH going even above the values in the control. However, net fecundity (NL) and net fertility (NH) of all treated females decreased considerably throughout the trial, indicating that survival rates of these females were lower, compared to the control. Calculated as total sums of gross and net daily schedules within five days, fecundity and fertility significantly decreased as spirodiclofen concentration increased. The two lowest concentrations failed to achieve a significant reduction of GL, while GH, NL, and NH were significantly lower than control values starting with the females treated with 6 mg/L. A high percentage of unhatched eggs, especially during the initial two days after treatment (35-100%), further contributed to the significant reduction in fertility of the females treated with spirodiclofen. All concentrations of spirodiclofen significantly reduced the instantaneous rate of increase. Regression analysis showed a linear population decline with increased acaricide concentrations (y = 1.13 - 0.24x; R2 = 0.91, p < 0.05).
Comparative effects of partial rootzone drying and deficit irrigation on growth and physiology of tomato plants
Authors: Savic Sladjana , Liu F. , Stikic Radmila , Jacobsen S.E. , Jensen C.R. , Jovanovic Zorica
Published: December 2009

The effects of partial rootzone drying (PRD), deficit irrigation (DI), and full irrigation (FI) on tomato physiology were investigated. In PRD and DI plants, leaf water potential values and stomatal conductance were significantly lower, while xylem ABA concentration was greater compared to FI plants. Photosynthesis was similar for all treatments. Water use efficiency was improved by PRD and DI, which reduced fruit dry weight, but had no effect on dry weight of leaves and stems.
Stomatal complex types, stomatal density, and the stomatal index in some species of dioscorea
Authors: Abdulrahaman A.A. , Egbedo F.O. , Oladele F.A.
Published: December 2009

Dioscorea alata L. has three stomatal complex types, namely, paracytic, anisocytic, and tetracytic stomata, with percentage frequency values of 50, 18, and 32, respectively. Dioscorea bulbifera has paracytic and anisocytic stomata, with percentage frequency values of 87.60 and 12.40, respectively. Dioscorea cayenensis has anisocytic stomata, with a percent?age frequency value of 100. Dioscorea dumetorum has tetracytic and paractytic stomata, with percentage frequency values of 91.05 and 8.95, respectively. Both D. esculenta and D. rotundata have paracytic stomata, with a percentage frequency of 100. The range of variation of stomatal density is from 10 (lowest value) in D. alata and D. dumentorum to 27 (highest value) in D. bulbifera. The stomatal index also varies, from 24 in D. alata to 47 in D. cayenensis. The size of stomata in all species is small, varying in length from 0.74 ?m in D. alata to 1.79 ?m in D. dumentorum. An indented dichotomous key based on stomatal features was constructed to distinguish and identify the species.
Spectroscopic and biological approach in the characterization of Cr(III), Mn(II) and Co(II) complexes with a novel hexaazamacrocyclic ligand derived from semicarbazide
Authors: Chandra Sulekh , Gautam Archana
Published: December 2009

Complexes of Cr(III), Mn(II) and Co(II) with a novel 5,7,12,14-tetraphenyl- 1,2,4,8,10,11-hexaazacyclotetradecane-3,9-dione macrocyclic ligand, THTD (L), were synthesized and characterized by elemental analysis, molar conductance and magnetic susceptibility measurements, as well as by mass, 1H-NMR, IR, electronic and EPR spectral studies. Based on the spectral studies, an octahedral geometry was assigned for the Cr(III), Mn(II) and Co(II) complexes. The ligand and its complexes were screened in vitro against some species of bacteria and plant pathogenic fungi. The metal complexes were found to be more active antimicrobial agents than the free ligand from which they were derived.
Temperature imposed textural and surface synergism affecting the isomerization activity of sulfated zirconia catalysts
Authors: Zarubica Aleksandra , Jovic Branislav , Nikolic Aleksandar , Putanov Paula , Boskovic Goran
Published: December 2009

Using sulfuric acid as the sulfating agent, two catalyst series were obtained from hydroxide and nitrate precursor with a sulfate loading identical to commercial sulfated hydroxide, i.e., 4.2 mass%. After calcination at 500, 600 and 700?C, all nine samples had various contents of residual sulfates depending on the origin of the catalyst. Accordingly, their surface properties were different, which, together with various textural properties, govern the formation of the active phase and their catalytic activity in the n-hexane isomerization reaction. The dominant activity and yield of mainly mono-branched isomers were attained in reaction at 200?C with a commercially sulfated zirconia catalyst calcined at 500?C. Among the SZ catalyst series synthesized from hydroxide and nitrate, the second according to its activity profile was similar to that of the commercially sulfated one, while samples originating from hydroxide showed some activity only after calcination at 600?C. This is due to the poorer textural properties of the hydroxide series, necessitating a higher calcination temperature in order to promote the simultaneous decomposition of S-containing species and their re-adsorption into the zirconia matrix following interaction and active phase formation. It seems that the tetragonal zirconia phase was not responsible for the catalytic activity but a synergistic effect of the textural properties of the samples and the sulfate loadings, which determine different acid strengths on the catalyst surface.
Probe on network-based collaborative maintenance mode for after-sales equipment
Authors: Sheng Tianwen , Chen Xiaohui , Yi Shuping , Gao Xiangbo , Ye Qiang , Lee Jay
Published: December 2009

As the structure and technologies of modern equipment become more and more complicated and it is hard to improve equipment's after-sales maintenance service under traditional mode, in this text, network-based collaborative maintenance mode for after-sales equipment was proposed. Specifically, under the leading of equipment manufacturer under guaranty or equipment user outside guaranty, manufacturer, user, designers, maintainers, spare parts suppliers and maintenance experts were integrated to establish dynamic alliance to carry out maintenance operations together based on network. In addition, the business process of network-based collaborative maintenance was analyzed and an information economics model of network-based collaborative maintenance was established to demonstrate the effectiveness of this maintenance mode.
Information Content and Value Relevance of Depreciation: A Cross-Industry Analysis
Authors: Kang Sok-Hyon , Zhao Yuping
Published: December 2009

ABSTRACT: Funds from Operations (FFO) is the prevailing performance measure in the Real Estate Investment Trust (REIT) industry. However, prior studies are inconclusive about the superiority of FFO over GAAP net income. Because depreciation is the largest reconciling item between FFO and net income, we examine the information content and value relevance of depreciation for both the REIT and non-REIT industries and report the following findings. First, accumulated depreciation is value-relevant for the REIT industry, whereas accumulated depreciation has little value relevance for comparably capital-intensive non-REIT industries. Second, accounting depreciation deviates from economic depreciation to a greater extent for REITs than for non-REIT industries. Third, accumulated depreciation has predictive ability for future revenues for REIT firms, but not for non-REIT firms. Finally, only the REIT industry displays all of these properties. In sum, evidence supports the REIT industry's assertion that GAAP depreciation consistently exceeds economic depreciation and that book value of assets is systematically understated.
Earnings Smoothness, Average Returns, and Implied Cost of Equity Capital
Authors: McInnis John
Published: December 2009

ABSTRACT: Despite a belief among corporate executives that smooth earnings paths lead to a lower cost of equity capital, I find no relation between earnings smoothness and average stock returns over the last 30 years. In other words, owners of firms with volatile earnings are not compensated with higher returns, as one would expect if volatile earnings lead to greater risk exposure. Although prior empirical work links smoother earnings to a lower implied cost of capital, I offer evidence that this link is driven primarily by optimism in analysts' long-term earnings forecasts. This optimism yields target prices and implied cost of capital estimates that are systematically too high for firms with volatile earnings. Overall, the evidence is inconsistent with the notion that attempts to smooth earnings can lead to a lower cost of equity capital.
Islet Cell Antibody–Positive Versus –Negative Phenotypic Type 2 Diabetes in Youth
Authors: Tfayli Hala , Bacha Fida , Gungor Neslihan , Arslanian Silva
Published: December 2009

OBJECTIVE

Using the clamp technique, youths with a clinical diagnosis of type 2 diabetes (CDx-type 2 diabetes) and positive pancreatic autoantibodies (Ab+) were shown to have severe impairment in insulin secretion and less insulin resistance than their peers with negative antibodies (Ab−). In this study, we investigated whether oral glucose tolerance test (OGTT)-derived indexes of insulin secretion and sensitivity could distinguish between these two groups.

RESEARCH DESIGN AND METHODS

A total of 25 Ab−, 11 Ab+ CDx-type 2 diabetic, and 21 obese control youths had an OGTT. Fasting and OGTT-derived indexes of insulin sensitivity (including the Matsuda index, homeostasis model assessment [HOMA] of insulin resistance, quantitative insulin sensitivity check index, and glucose-to-insulin ratio) and insulin secretion (HOMA of insulin secretion and 30-min insulogenic and C-peptide indexes) were used. Glucagon and glucagon-like peptide (GLP)-1 responses were assessed.

RESULTS

Fasting C-peptide and C-peptide–to–glucose ratio, and C-peptide area under the curve (AUC) were significantly lower in the Ab+ CDx-type 2 diabetic patients. Other OGTT-derived surrogate indexes of insulin sensitivity and secretion were not different between the Ab+ versus Ab− patients. GLP-1 during the OGTT was highest in the Ab+ youths compared with the other two groups, but this difference disappeared after adjusting for BMI. Ab+ and Ab− CDx-type 2 diabetes had relative hyperglucagonemia compared with control subjects.

CONCLUSIONS

The clinical measures of fasting and OGTT-derived surrogate indexes of insulin sensitivity and secretion, except for fasting C-peptide and C-peptide AUC, are less sensitive tools to distinguish metabolic/pathopysiological differences, detected by the clamp, between Ab+ and Ab− CDx-type 2 diabetic youths. This underscores the importance of using more sensitive methods and the importance of determining antibody status in obese youths with CDx-type 2 diabetes.
Six Months of Diazoxide Treatment at Bedtime in Newly Diagnosed Subjects With Type 1 Diabetes Does Not Influence Parameters of β-Cell Function and Autoimmunity but Improves Glycemic Control
Authors: Radtke Maria Anita , Nermoen Ingrid , Kollind Magnus , Skeie Svein , Sørheim Jan Inge , Svartberg Johan , Hals Ingrid , Moen Torolf , Dørflinger Gry Høst , Grill Valdemar
Published: December 2009

OBJECTIVE

Continuous β-cell rest with diazoxide preserves residual endogenous insulin production in type 1 diabetes. However, side effects have hampered therapeutic usefulness. In a double-blind study, we tested whether lower, intermittent dosing of diazoxide had beneficial effects on insulin production, metabolic control, and autoimmunity markers in the absence of side effects.

RESEARCH DESIGN AND METHODS

Forty-one newly diagnosed type 1 diabetic patients were randomized to 6 months of treatment with placebo or 100 mg diazoxide at bedtime. A1C, C-peptide (fasting and glucagon stimulated), and FoxP3+ regulatory T-cells (Tregs) were measured. Patients were followed for 6 months after intervention.

RESULTS

Of six dropouts, three were due to perceived side effects; one subject in the diazoxide group experienced rash, another dizziness, and one in the placebo group sleep disturbance. Adverse effects in others were absent. Diazoxide treatment reduced A1C from 8.6% at baseline to 6.0% at 6 months and 6.5% at 12 months. Corresponding A1C value in the placebo arm were 8.3, 7.3, and 7.5% (P < 0.05 for stronger reduction in the diazoxide group). Fasting and stimulated C-peptide decreased during 12 months similarly in both arms (mean −0.30 and −0.18 nmol/l in the diazoxide arm and −0.08 and −0.09 nmol/l in the placebo arm). The proportion of Tregs was similar in both arms and remained stable during intervention but was significantly lower compared with nondiabetic subjects.

CONCLUSIONS

Six months of low-dose diazoxide was without side effects and did not measurably affect insulin production but was associated with improved metabolic control.
The Literary History of the Sash Window
Authors: Ramsey Rachel
Published: December 2009

Invented in England in the final decades of the seventeenth century, the sash window quickly replaced the casement window, becoming a defining feature of eighteenth-century English architecture. With its liberal use of expensive panes of glass, its vertical opening system, and its novel rope-and-pulley mechanism, the sash window attracted attention from those interested in scientific advancement, supporters of new English inventions, and those who longed for what was new and fashionable. While architectural historians have long noted the sash window's predominance in English architecture, literary historians and critics have overlooked how the sash window often features as one of the few descriptive details in early modern fiction. After a short history of the sash window, this essay examines the literary significance of the sash window in works ranging from Jonathan Swift's Gulliver Travels and Laurence Sterne's Tristram Shandy to Samuel Johnson's Journey to the Western Islands and Jane Austen's Northanger Abbey.
Talking Coins and Thinking Smoke-Jacks: Satirizing Materialism in Gildon and Sterne
Authors: Nowka Scott
Published: December 2009

Both Charles Gildon and Laurence Sterne, authors associated with libertine ideas early in their careers, later used their fiction to distance themselves from materialist philosophy, creating influential characters in the process. Gildon satirized materialism by bringing coins to life in his object narrative The Golden Spy, while Sterne's method was to reduce the humanity of characters such as Uncle Toby in Tristram Shandy to the level of hobby-horses and smoke-jacks. Together, these two disparate examples reveal the dangerousness of materialist ideas at this time as well as the cultural pervasiveness of materialist thinking in eighteenth-century Britain, as represented in canonical and non-canonical works.
Remarks on Richardson: Sarah Fielding and the Rational Reader
Authors: Friedman Emily C.
Published: December 2009

Sarah Fielding promoted rational reading practices through techniques that often differed from those used in the mid-eighteenth-century novel, particularly the contrary techniques employed by Samuel Richardson and her brother, Henry Fielding. Examining Fielding's Remarks on Clarissa and her co-authored “dramatic fable” The Cry, this essay argues that Fielding creates textual spaces where her readers can and should examine their similarities with imperfect objects. Through both character and form, Fielding provides a number of “hooks” into her central message, all designed to engage more than one type of reader. At the same time, Fielding's work provides commentary on the work of her friend and mentor Samuel Richardson: explicitly in Remarks on Clarissa and implicitly in The Cry, the latter of which engages with Richardson's final novel, Sir Charles Grandison, in ways that have not been noted until now.
Publishing as a Vocation
Authors: Horowitz Irving Louis
Published: December 2009

‘Publishing as a Vocation’ relates a series of policy decisions and episodes that exemplify the politics of publishing. The emphasis is on case studies that confront scholarly publishers with the political, community, and ideological forces that each must confront in quotidian ways. The essay, written in the spirit of Max Weber's ‘Science as a Vocation,’ is non-judgemental, but making it clear that manuscript decisions extend far beyond the quality of the works accepted, rejected, or cancelled in a volatile academic and intellectual setting. It is hoped for, rather than argued, that once these extrinsic parameters are confronted, the nature of the service to the professional worlds being served can be understood, and perhaps significantly improved in a new publishing context.
Launching a New Academic Journal: Twenty Years Later
Authors: Fischer Charles C.
Published: December 2009

This article is a retrospective, examining two decades of my tenure as editor-in-chief of a prominent management journal—my successes, failures, and lessons learned. The article offers insights and suggestions for those launching a new journal and those new to editing a journal. Some of the ideas presented may also be of interest to the experienced editor, such as the use of an administrative fee instead of a submission fee and a new twist on page fees. The guiding theme is that of the editor as a servant leader.
Observations on an Emergent Specialization
Authors: Hérubel Jean-Pierre V.M.
Published: December 2009

The historical profession and its attendant scholarship are composed of different specializations and sub-disciplines. Among these, political, economic, and social history are well known. Recently, historical research has encompassed such fields as environmental, gender, and ethnic history to complement such diverse specialties as history of science, history of technology, and history of exploration. In the past twenty years, cultural history has emerged in France, with characteristics that have engaged newly honed orientations toward the historical examination of cultural production and cultural objects, if not processes. Informed by philosophical and historiographic analysis, as well as by interdisciplinary interventions in historical research and scholarship, contemporary French cultural history focuses on the history of publishing, scholarship, mass media and spectacles, libraries, and museums, as well as opera and music. Not confined to these, contemporary French cultural history privileges specialization in nineteenth- and twentieth-century French phenomena, in the main, but its historiographic innovation and publication extend to an international audience. This cursory and exploratory essay attempts to situate contemporary French cultural history as a specialization and as a vector in the contemporary historiographic landscape.
Prediction of reduction potentials from calculated electron affinities for metal-salen compounds
Authors: Bateni Sarah B , England Kellie R , Galatti Anthony T , Kaur Handeep , Mendiola Victor A , Mitchell Alexander R , Vu Michael H , Gherman Benjamin F , Miranda James A
Published: December 2009

The electron affinities (EAs) of a training set of 19 metal-salen compounds were calculated using density functional theory. Concurrently, the experimental reduction potentials for the training set were measured using cyclic voltammetry. The EAs and reduction potentials were found to be linearly correlated by metal. The reduction potentials of a test set of 14 different metal-salens were then measured and compared to the predicted reduction potentials based upon the training set correlation. The method was found to work well, with a mean unsigned error of 99 mV for the entire test set. This method could be used to predict the reduction potentials of a variety of metal-salen compounds, an important class of coordination compounds used in synthetic organic electrochemistry as electrocatalysts.