bluuebunny/crossref_metadata_2025 huggingface dataset:
Conversion from Continuous Insulin Infusions to Subcutaneous Insulin in Critically III Patients
Authors: Weant Kyle A , Ladha Alim
Published: April 2009

Background:

Continuous insulin infusions have become a standard of care in many intensive care units (ICUs); however, methods for transitioning patients from continuous infusions to other insulin therapies have not been extensively evaluated.

Objective:

To determine the most effective method for transitioning ICU patients from continuous insulin infusions to subcutaneous insulin therapy.

Methods:

A searchable pharmacy database at the University of North Carolina Hospitals was used to retrospectively identify adults admitted to the neurosurgery ICU and prescribed a continuous insulin infusion between May 2007 and February 2008, All patients were transitioned to subcutaneous insulin upon floor transfer. Patients were stratified according to the dose of subcutaneous insulin as a percentage of their prior 24-hour continuous insulin requirement and then analyzed on the rate of achievement of goal blood glucose values (80–150 mg/dL) within the first 48 hours after transition.

Results:

A total of 769 blood glucose values from 79 patients were recorded during the study. Data analysis demonstrated significantly lower median blood glucose values with the use of subcutaneous insulin doses that were 60–70% of insulin infusion requirements when compared with all other groups. For patients without a history of diabetes mellitus, the use of a subcutaneous dose that was 60–70% of the insulin infusion requirement resulted in a significantly greater percentage of patients within the target range compared with other groups (78%; p < 0.05). For those with a history of diabetes, subcutaneous doses higher than 70% of the insulin infusion requirement yielded the most frequent achievement of target values, although there was substantial variability within this group. No significant difference was noted in the incidence of hypoglycemia (blood glucose <80 mg/dL) between groups, although the frequency of hypoglycemia was almost twice as high in the group with diabetes as in those without it (4.2% vs 2.2%).

Conclusions:

Methods currently used to transition patients off insulin infusions vary widely. Initial data suggest that utilizing 60–70% of the 24-hour insulin infusion requirement as a subcutaneous dose would result in blood glucose values of 80–150 mg/dL 70% of the time. Further study is necessary to adequately assess the optimal insulin infusion transition protocol for critically ill patients to ensure both safety and efficacy.
Role of Trabecular Microarchitecture in Whole-Vertebral Body Biomechanical Behavior
Authors: Fields Aaron J , Eswaran Senthil K , Jekir Michael G , Keaveny Tony M
Published: April 2009

The role of trabecular microarchitecture in whole-vertebral biomechanical behavior remains unclear, and its influence may be obscured by such factors as overall bone mass, bone geometry, and the presence of the cortical shell. To address this issue, 22 human T9 vertebral bodies (11 female; 11 male; age range: 53–97 yr, 81.5 ± 9.6 yr) were scanned with μCT and analyzed for measures of trabecular microarchitecture, BMC, cross-sectional area, and cortical thickness. Sixteen of the vertebrae were biomechanically tested to measure compressive strength. To estimate vertebral compressive stiffness with and without the cortical shell for all 22 vertebrae, two high-resolution finite element models per specimen—one intact model and one with the shell removed—were created from the μCT scans and virtually compressed. Results indicated that BMC and the structural model index (SMI) were the individual parameters most highly associated with strength (R2 = 0.57 each). Adding microarchitecture variables to BMC in a stepwise multiple regression model improved this association (R2 = 0.85). However, the microarchitecture variables in that regression model (degree of anisotropy, bone volume fraction) differed from those when BMC was not included in the model (SMI, mean trabecular thickness), and the association was slightly weaker for the latter (R2 = 0.76). The finite element results indicated that the physical presence of the cortical shell did not alter the relationships between microarchitecture and vertebral stiffness. We conclude that trabecular microarchitecture is associated with whole-vertebral biomechanical behavior and that the role of microarchitecture is mediated by BMC but not by the cortical shell.
BDNF Exerts Contrasting Effects on Peripheral Myelination of NGF-Dependent and BDNF-Dependent DRG Neurons
Authors: Xiao Junhua , Wong Agnes W. , Willingham Melanie M. , Kaasinen Selma K. , Hendry Ian A. , Howitt Jason , Putz Ulrich , Barrett Graham L. , Kilpatrick Trevor J. , Murray Simon S.
Published: April 2009

Although brain-derived neurotrophic factor (BDNF) has been shown to promote peripheral myelination during development and remyelination after injury, the precise mechanisms mediating this effect remain unknown. Here, we determine that BDNF promotes myelination of nerve growth factor-dependent neurons, an effect dependent on neuronal expression of the p75 neurotrophin receptor, whereas BDNF inhibits myelination of BDNF-dependent neurons via the full-length TrkB receptor. Thus, BDNF exerts contrasting effects on Schwann cell myelination, depending on the complement of BDNF receptors that are expressed by different subpopulations of dorsal root ganglion neurons. These results demonstrate that BDNF exerts contrasting modulatory roles in peripheral nervous system myelination, and that its mechanism of action is acutely regulated and specifically targeted to neurons.
Perceptual Relearning of Complex Visual Motion after V1 Damage in Humans
Authors: Huxlin Krystel R. , Martin Tim , Kelly Kristin , Riley Meghan , Friedman Deborah I. , Burgin W. Scott , Hayhoe Mary
Published: April 2009

Damage to the adult, primary visual cortex (V1) causes severe visual impairment that was previously thought to be permanent, yet several visual pathways survive V1 damage, mediating residual, often unconscious functions known as “blindsight.” Because some of these pathways normally mediate complex visual motion perception, we asked whether specific training in the blind field could improve not just simple but also complex visual motion discriminations in humans with long-standing V1 damage. Global direction discrimination training was administered to the blind field of five adults with unilateral cortical blindness. Training returned direction integration thresholds to normal at the trained locations. Although retinotopically localized to trained locations, training effects transferred to multiple stimulus and task conditions, improving the detection of luminance increments, contrast sensitivity for drifting gratings, and the extraction of motion signal from noise. Thus, perceptual relearning of complex visual motion processing is possible without an intact V1 but only when specific training is administered in the blind field. These findings indicate a much greater capacity for adult visual plasticity after V1 damage than previously thought. Most likely, basic mechanisms of visual learning must operate quite effectively in extrastriate visual cortex, providing new hope and direction for the development of principled rehabilitation strategies to treat visual deficits resulting from permanent visual cortical damage.
Microglia Mediate the Clearance of Soluble Aβ through Fluid Phase Macropinocytosis
Authors: Mandrekar Shweta , Jiang Qingguang , Lee C. Y. Daniel , Koenigsknecht-Talboo Jessica , Holtzman David M. , Landreth Gary E.
Published: April 2009

Alzheimer's disease is characterized by the progressive deposition of β-amyloid (Aβ) within the brain parenchyma and its subsequent accumulation into senile plaques. Pathogenesis of the disease is associated with perturbations in Aβ homeostasis and the inefficient clearance of these soluble and insoluble peptides from the brain. Microglia have been reported to mediate the clearance of fibrillar Aβ (fAβ) through receptor-mediated phagocytosis; however, their participation in clearance of soluble Aβ peptides (sAβ) is largely unknown. We report that microglia internalize sAβ from the extracellular milieu through a nonsaturable, fluid phase macropinocytic mechanism that is distinct from phagocytosis and receptor-mediated endocytosis bothin vitroandin vivo. The uptake of sAβ is dependent on both actin and tubulin dynamics and does not involve clathrin assembly, coated vesicles or membrane cholesterol. Upon internalization, fluorescently labeled sAβ colocalizes to pinocytic vesicles. Microglia rapidly traffic these soluble peptides into late endolysosomal compartments where they are subject to degradation. Additionally, we demonstrate that the uptake of sAβ and fAβ occurs largely through distinct mechanisms and upon internalization are segregated into separate subcellular vesicular compartments. Significantly, we found that upon proteolytic degradation of fluorescently labeled sAβ, the fluorescent chromophore is retained by the microglial cell. These studies identify an important mechanism through which microglial cells participate in the maintenance of Aβ homeostasis, through their capacity to constitutively clear sAβ peptides from the brain.
BNIP3 (Bcl-2 19 kDa Interacting Protein) Acts as Transcriptional Repressor of Apoptosis-Inducing Factor Expression Preventing Cell Death in Human Malignant Gliomas
Authors: Burton Teralee R. , Eisenstat David D. , Gibson Spencer B.
Published: April 2009

The Bcl-2 19 kDa interacting protein (BNIP3) is a pro-cell-death BH3-only member of the Bcl-2 family. We previously found that BNIP3 is localized to the nucleus in the majority of glioblastoma multiforme (GBM) tumors and fails to induce cell death. Herein, we have discovered that nuclear BNIP3 binds to the promoter of the apoptosis-inducing factor (AIF) gene and represses its expression. BNIP3 associates with PTB-associating splicing factor (PSF) and HDAC1 (histone deacetylase 1) contributing to transcriptional repression of the AIF gene. This BNIP3-mediated reduction in AIF expression leads to decreased temozolomide-induced apoptosis in glioma cells. Furthermore, nuclear BNIP3 expression in GBMs correlates with decreased AIF expression. Together, we have discovered a novel transcriptional repression function for BNIP3 causing reduced AIF expression and increased resistance to apoptosis. Thus, nuclear BNIP3 may confer a survival advantage to glioma cells and explain, in part, why BNIP3 is expressed at high levels in solid tumors, especially GBM.
International Perspectives
Authors: Kugelman Amir
Published: April 2009

NRS is a noninvasive method of maintaining functional residual capacity without endotracheal ventilation. NRS, which includes nasal continuous positive airway pressure (NCPAP) and nasal ventilation, is an effective mode of treatment for preterm infants, especially in the era of prenatal corticosteroids. NRS has been used for the initial treatment of RDS, after extubation as a “bridge” to spontaneous unsupported breathing, and for the treatment of apnea of prematurity. However, NRS may not be sufficiently effective alone as the primary therapy for preterm infants who have RDS, especially for extremely preterm infants who have severe RDS. A significant number of such infants still need endotracheal ventilation, possibly due, in part, to not using surfactant. A new approach involves administration of surfactant during brief intubation followed by immediate extubation to NRS. This review examines recently developed noninvasive ventilatory strategies and offers a logical physiologic and evidence-based flow chart to aid in bedside decision making from the delivery room to the point of spontaneous unsupported breathing. Also discussed are issues that may be especially pertinent to outlying facilities that have limited personnel and equipment resources.
The Intestinal Immune Barrier
Authors: Louis Nancy A. , Lin Patricia W.
Published: April 2009

As the largest interface with the external environment, the mature intestinal epithelium has remarkable physiologic responsibilities. The intestine must function first as an organ of absorption and digestion while simultaneously protecting itself from the vast bacterial flora, array of food antigens, and physiochemical stresses caused by digestive and microbial products. Thus, the intestinal epithelium must be permeable to nutrients and fluids, yet remain impermeable to potentially injurious chemicals and pathogens. The intestine also must differentiate between commensal organisms whose growth is encouraged and enteric pathogens that need to be suppressed or eliminated. The single layer of cells comprising the intestinal epithelium is critical for maintenance of this dynamic barrier. The developing neonatal gut faces an additional daunting challenge of successfully negotiating the transition from a sterile lumen devoid of digestive and microbial metabolic products to the fully realized “bioreactor” of the adult gut. This review describes the unique structural features and elements of innate host defense elaborated by this dynamic tissue.
Key parameters dictating strength of lime/cement-treated soils
Authors: Consoli N. C. , da Silva Lopes L. , Foppa D. , Heineck K. S.
Published: April 2009

An effort is being carried out to develop dosage methodologies for improved soils based on a rational criterion, as in concrete technology, where the water/cement ratio plays a fundamental role in target strength assessment. This study aims to assess the strength-controlling parameters of a sandy lean clay treated with lime or cement, and to show that the void/cementitious material content ratio plays a fundamental role in target strength assessment. The controlling parameters evaluated were the amount of cementitious material, the porosity, the moisture content, and the void/cementitious material ratio. A number of unconfined compression tests and suction measurements were carried out in the present work. The results show that the unconfined compressive strength (UCS) increased linearly (with a reduced strength gain rate) with lime content for soil–lime mixtures. A power function fits the UCS–cement relationship better for soil–cement mixtures. The UCS increased linearly with the reduction in porosity for soil–lime mixtures and exponentially for soil–cement mixtures. Finally, the porosity/volumetric cementitious material content is shown to be a good parameter in the evaluation of the unconfined compressive strength of the soil studied.
Successful Field Trial of a Novel Abrasive Jetting Tool Designed to Create Large Diameter-Long Cavities in the Formation to Enhance Stimulation Treatments
Authors: Solares J. Ricardo , Amorocho J. Ricardo , Bartko K. , Leising L. , Erkol Z. , Kelkar S. , Venkateshwaran R. , Saldeev R.
Published: April 2009

Gas exploration wells are being drilled in high pressure and temperature environments targeting low permeability and high fracture gradient formations that push the envelope of conventionally used technologies. Thus, conventional perforating techniques are often not sufficient to break down the formation during fracturing operations in this type of wells.

A novel system, specially designed to enable hydraulic fracturing in challenging producers was successfully field-tested. The system includes an anchor, a multi-cycle incrementing and stroking tool (MCIST), and a jetting sub with multiple nozzles. The anchor is used to prevent axial motion of the jetting head while jet cutting, which overcomes the long-standing problem of tubing stretch due to pressure changes and vibration during abrasive perforating operations. With the anchor as a depth reference base, the MCIST changes length upon command from the surface and uses sequential jetting to create a series of evenly spaced perforations in the casing, with corresponding large diameter longitudinal slots in the formation, in a controlled and evenly spaced fashion. The tool design and testing process, details about the field trial experience as part of a stimulation treatment, and the excellent post-stimulation results achieved are discussed in the paper.
Evaluation of owner attachment to dogs on the basis of whether owners are legally considered guardians of their pets
Authors: Helms Timothy D. , Bain Melissa J.
Published: April 2009

Objective—To evaluate whether dog owners who are legally considered guardians are more attached to their dogs than those who are not.

Design—Cross-sectional study.

Sample Population—Dog owners from northern California.

Procedures—274 dog owners completed a standardized survey while visiting full-service veterinary and mobile vaccination clinics in a city in which dog owners were legally designated as owner/guardian and in another city in which no such designation was made. Degree of owner attachment to their dog was assessed with a standardized scale.

Results—The degree to which owners were attached to their dog was associated with city of residence, owner age, and whether owners were completely satisfied with their dog's behavior. Owners residing in the guardian city had a lower attachment score. There was no significant difference in the percentage of dogs vaccinated against rabies in each city, nor was there any difference in the percentage of licensed dogs. Attachment scores did not differ between participants who visited mobile versus free-standing clinics. Owners with > 1 dog in their household reported a higher degree of attachment to the study dog than did owners of 1 dog.

Conclusions and Clinical Relevance—Dog owners residing in a city where owners were legally designated as an owner/guardian were no more attached to their dog than those living in a city without such a designation. Although results did not indicate a negative impact of the term guardian, its use was not associated with an enhanced bond between owner and dog.
Outcomes of podotrochlear (navicular) bursa injections for signs of foot pain in horses evaluated via magnetic resonance imaging: 23 cases (2005–2007)
Authors: Bell Chris D. , Howard Rick D. , Taylor D. Scott , Voss Ed D. , Werpy Natasha M.
Published: April 2009

Objective—To determine clinical outcome following intrathecal injection of the podotrochlear (navicular) bursa for signs of foot pain in horses evaluated via magnetic resonance imaging (MRI) and evaluate efficacy of corticosteroids administered with or without hyaluronate.

Design—Retrospective case series.

Animals—23 horses.

Procedures—Data collected included signalment, history, intended use, duration and severity of lameness, results of diagnostic anesthesia, radiographic abnormalities, MRI abnormalities, and outcomes for return to use.

Results—MRI was conducted on 23 horses with lameness localized to the foot. Thirteen horses had bilateral forelimb lameness, and 10 had unilateral forelimb lameness. Mean duration of lameness was 10.5 months. Seventeen of 23 (74%) horses had excellent outcomes and returned to intended use within 2 to 4 weeks after navicular bursa injection. Hyaluronate treatment was not associated with outcome; however, horses receiving < 10 mg of trimacinolone had significantly worse outcomes than those treated with hyaluronate. Among horses with excellent outcomes, mean duration of soundness was 7.3 months. Seven of 8 horses with erosive lesions of the flexor surface of the distal sesamoid (navicular) bone diagnosed via MRI had a poor outcome. Horses with navicular bursitis responded optimally to injection, compared with horses with other problems.

Conclusions and Clinical Relevance—Results suggested that intrathecal injection of corticosteroid in horses with erosions of the flexor surface of the navicular bone associated with deep digital flexor tendon adhesions yielded a poor response. Treatment of horses with navicular bursitis via injection of the navicular bursa should be highly effective in alleviating lameness.
Plant species richness and composition in the arable land of Kosovo
Authors: Mehmeti Arben , Demaj Adem , Waldhardt Rainer
Published: April 2009

This study investigates today's plant species richness and composition in cultivated and recently abandoned arable land of Kosovo. Relationships between these aspects of vegetation and both environmental features and agricultural management measures are studied at the regional and plot scale. In 2006, 432 vegetation relevés with a standard plot size of 25 m 2 were recorded in cultivated fields. In 2007, data collection focussed on 41 plots in arable fields that had been abandoned the year before. With respect to the environment, data analysis accounts for topography, soil base-richness and moisture, and geographic location. As to the management, crops and weed control are considered. A total number of 235 species was documented. In comparison to literature dating back to about 1980, the regional weed flora considerably changed. At the plot scale, today's weed flora of Kosovo is fairly species-poor and species composition is rather uniform between plots. According to General Regression Model analyses, Indicator Species Analyses and Detrended Correspondence Analyses, species richness and composition mainly differ between crops and weed management, with highest mean species richness in recently abandoned and lowest in herbicide-treated maize fields.
Marker Imputation in Barley Association Studies
Authors: Jannink Jean‐Luc , Iwata Hiroyoshi , Bhat Prasanna R. , Chao Shiaoman , Wenzl Peter , Muehlbauer Gary J.
Published: April 2009

Association mapping requires high marker density, potentially leading to many missing marker data and to high genotyping costs. In human genetics, methods exist to impute missing marker data and whole markers typed in a reference panel but not in the experimental dataset. We sought to determine if an imputation method developed for human data would function effectively in a barley (Hordeum vulgare L.) panel. The panel contained 98 lines, 2517 single nucleotide polymorphism (SNP) markers, and 716 Diversity Arrays Technology (DArT) markers. Averaged over markers, masked scores were correctly imputed 97.1% of the time. We chose 610 and 273 tag markers in two‐ and six‐row barley subpopulations, respectively. Despite this low number of tags, imputation accuracy was such that for about 80% of non‐tag markers, the prediction r2 between imputed and true scores was 0.8 or higher. When DArT markers were used as tags, SNP markers were imputed with similar accuracy, suggesting that the method can convert association information from one marker system (e.g., DArT) to another marker system (e.g., SNP). We believe marker imputation methods will have an important future in association studies as a component of tagging methods and in reducing problems due to missing data.
Sweet Sorghum Genetic Diversity and Association Mapping for Brix and Height
Authors: Murray Seth C. , Rooney William L. , Hamblin Martha T. , Mitchell Sharon E. , Kresovich Stephen
Published: April 2009

Sweet sorghum [Sorghum bicolor (L.) Moench], like its close relative, sugarcane (Saccharum spp.), has been selected to accumulate high levels of edible sugars in the stem. Sweet sorghums are tall and produce high biomass in addition to sugar. Little has been documented about the genetic relationships and diversity within sweet sorghums and how sweet sorghums relate to grain sorghum racial types. In this study, a diverse panel of 125 sorghums (mostly sweet) was successfully genotyped with 47 simple sequence repeats (SSRs) and 322 single nucleotide polymorphisms (SNPs). Using both distance‐based and model‐based methods, we identified three main genetic groupings of sweet sorghums. Based on observed phenotypes and known origins we classified the three groups as historical and modern syrup, modern sugar/energy types, and amber types. Using SSR markers also scored in an available large grain sorghum germplasm panel, we found that these three sweet groupings clustered with kafir/bicolor, caudatum, and bicolor types, respectively. Using the information on population structure and relatedness, association mapping was performed for height and stem sugar (brix) traits. Three significant associations for height were detected. Two of these, on chromosomes 9 and 6, support published QTL studies. One significant association for brix, on chromosome 1, 12kb from a glucose‐6‐phosphate isomerase homolog, was detected.
Comparative Analysis and Functional Annotation of a Large Expressed Sequence Tag Collection of Apple
Authors: Gasic Ksenija , Gonzalez Delkin O. , Thimmapuram Jyothi , Liu Lei , Malnoy Mickael , Gong George , Han Yuepeng , Vodkin Lila O. , Aldwinckle Herb S. , Carroll Natalie J. , Orvis Kathryn S. , Goldsbrough Peter , Clifton Sandra , Pape Deana , Fulton Lucinda , Martin John , Theising Brenda , Wisniewski Michael E. , Fazio Gennaro , Feltus Frank A. , Korban Schuyler S.
Published: April 2009

A total of 34 apple (Malus × domestica Borkh.) cDNA libraries were constructed from root, leaf, bud, shoot, flower, and fruit tissues, at various developmental stages and/or under biotic or abiotic stress conditions, and of several genotypes. From these libraries, 190,425 clones were partially sequenced from the 5′ end and 42,619 clones were sequenced from the 3′ end, and a total of 182,241 high‐quality expressed sequence tags (ESTs) were obtained. These coalesced into 23,442 tentative contigs and 9843 singletons, for a total of 33,825 apple unigenes. Functional annotation of this unigene set revealed an even distribution of apple sequences among the three main gene ontology categories. Of ∼33,000 apple unigenes, 8437 (25%) had no detectable homologs (E >0.1) in the Arabidopsis genome. When the entire apple unigene set was compared with the entire citrus [Citrus sinensis (L.) Osbeck] unigene set and the poplar (Populus trichocarpa Torr. & Gray) predicted proteome, both members of the core eudicot and rosids clade, 13,521 of apple unigenes matched one or more sequences in citrus, while 25,817 had counterparts in the poplar protein database. Apple–Arabidopsis–citrus–poplar comparisons revealed closer evolutionary relationships between apple and poplar than with the other two species. Genes involved in basic metabolic pathways appear to be largely conserved among apple, citrus, poplar, and Arabidopsis.
Equivalence between adaptive feedforward cancellation and disturbance rejection using the internal model principle
Authors: Guo Xiuyan , Bodson Marc
Published: April 2009

The paper shows that a large class of adaptive algorithms for disturbance cancellation yields control systems that are equivalent to compensators implementing the internal model principle (IMP). The fact has been known to be true for periodic disturbances with fixed frequency. However, the paper shows that the result can be extended to disturbances of time‐varying frequency (i.e. frequency‐modulated signals), regardless of the rate of variation of the frequency. In particular, several adaptive controllers are shown to be equivalent to linear time‐varying compensators implementing the IMP. Further, a pseudo‐gradient algorithm produces the same responses as a polytopic linear parameter‐varying compensator. Copyright © 2009 John Wiley & Sons, Ltd.
Structural change and market power in the U.S. food manufacturing sector
Authors: Stiegert Kyle W. , Wang Shinn‐Shyr , Rogers Richard T.
Published: April 2009

This study develops an intertemporally linked market model to explore the relationships between price‐cost margins, market concentration, and advertising outlay. The study used data from 48 four‐digit SIC (standardized industrial classification) codes for the Food and Tobacco Processing Industries during the 1970s, 1980s, and 1990s. The authors' findings provide evidence that both high and low levels of performance provide signals to industries to consolidate, but for obvious and different reasons. Further, increased consolidation leads to increased entry barriers (advertising) and higher profits to the industry. Our findings are supportive of both Chicago and Traditionalist Schools of thought about antitrust enforcement: Neither emerges in a dominant position. Endogeneity issues and findings within the intertemporal structure cast considerable doubt about overly simplistic structure–performance paradigms of firm behavior. [JEL Code: L11, L40, L66]. © 2009 Wiley Periodicals, Inc.
Evidence of the role of marketing arrangements and valuation methods in improving beef quality
Authors: Liu Yanyan , Muth Mary K. , Koontz Stephen R. , Lawrence John D.
Published: April 2009

Low and inconsistent beef quality has been blamed by some for the losses of beef's share of total meat consumption. Tighter vertical coordination through use of alternative marketing arrangements and more precise price signaling through use of different cattle valuation methods may help improve beef quality because these mechanisms facilitate information exchange enabling producers to respond better to consumer demand. For the congressionally mandated Livestock and Meat Marketing Study, we modeled differences in levels and variances of cattle quality associated with particular marketing arrangements and valuation methods using fed cattle purchase data from 29 large U.S. beef packing plants for October 2002 through March 2005. Results indicate fed cattle procured through marketing agreements and packer ownership had higher and more consistent quality compared to other types of arrangements. Auction market cattle quality was the most inconsistent. Fed cattle valued using carcass weight with a grid were associated with higher and more consistent quality. [EconLit Citation: Q13]. © 2009 Wiley Periodicals, Inc.
Fast identification of thermostable beta‐glucosidase mutants on cellobiose by a novel combinatorial selection/screening approach
Authors: Liu Wenjin , Hong Jiong , Bevan David R. , Zhang Y.‐H. Percival
Published: April 2009

Engineering costly cellulases on natural cellulosic substrates is of importance for emerging biomass‐based biorefineries. Directed enzyme evolution is becoming a popular tool, but identification of desired mutants from a large mutant library remains challenging sometimes. In this work, we demonstrated a novel combinatorial selection/screening strategy for finding thermostable beta‐glucosidase on its natural substrate—cellobiose. First, selection was conducted through complementation of beta‐glucosidase for non‐cellobiose‐utilizing Escherichia coli so that only the cells expressing active beta‐glucosidase can grow on a M9 synthetic medium with cellobiose as the sole carbon source (selection plate). Second, the clones on the selection plates were duplicated by using nylon membranes. After heat treatment, the nylon membranes were overlaid on M9/cellobiose screening plates so that remaining activities of thermostable beta‐glucosidase mutants hydrolyzed cellobiose on the screening plates to glucose. Third, the growth of an indicator E. coli strain that can utilize glucose but not cellobiose on the screening plates helped detect the thermostable beta‐glucosidase mutants on the selection plates. Several thermostable mutants were identified from a random mutant library of the Paenibacillus polymyxa beta‐glucosidase. The most thermostable mutant A17S had an 11‐fold increase in the half‐life of thermoinactivation at 50°C. Biotechnol. Bioeng. 2009;103: 1087–1094. © 2009 Wiley Periodicals, Inc.
Testing accuracy of analytical methods by regression
Authors: Kemény S. , Deák A. , Bánfai B.
Published: April 2009

The usual procedures for testing the accuracy of analytical methods are criticized. Testing the average bias, as well as zero intercept and unit slope are all questionable procedures. Application of the general regression hypothesis test is applicable, but its pair of hypotheses is not relevant. The relevant question is: if the bias exceeds an acceptable level or not? This is an interval hypothesis, that may be properly tested using the two one‐sided t‐tests (TOST) approach. It is practically executed by calculating the 1–2β confidence band for the bias, and checking if it is within the allowed interval throughout the concentration range. If the bias does not depend on the concentration, this method is identical to the TOST procedure for the average bias. Copyright © 2009 John Wiley & Sons, Ltd.
A new piezoelectric single crystal obtained by Ge doping in the SiO2 structure
Authors: Miclau M. , Miclau N. , Poienar M. , Grozescu I.
Published: April 2009

The interest of Si1–xGexO2 single crystals with alpha‐quartz structure is connected to improvement of electromechanical coefficients and rise of α – β phase transition of quartz one. Growth of an α‐SixGe1–xO2 crystal was realized by a hydrothermal method of temperature gradient in autoclaves, made from Cr–Ni alloys. Nutrient material was prepared from synthetic quartz as crashed rods and placed in the bottom of autoclaves. There was loaded GeO2 powder additive in proportions to quartz nutrient. Single crystals were investigated by electron microprobe analysis, X‐ray diffraction and atomic force microscopy. The most important result, which was obtained during the investigations, is an experimental proof of growth of α‐SixGe1–xO2 single crystals under the hydrothermal conditions. The present results thus open the possibility to tune the piezoelectric properties of these materials by varying the chemical composition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and structural analysis of angled Te nanocrystals
Authors: Deng D. W. , Li P. , Gu Y. Q.
Published: April 2009

In this paper, a new direct method to prepare angled Te nanocrystals (NCs) in the isotropic thiol‐ligand system from the transformation of MA‐stabilized CdTe nanoparticles (NPs) induced by the post‐addition of L‐cysteine was presented, without removing aforehand the protective shell of organic stabilizer. Besides nanorods, angled Te nanocrystals, including nanocheckmarks, X‐shaped, nanomoths, y‐shaped, and so on, also were obtained. By means of high‐resolution transmission electron microscopy (HRTEM), selected‐area electron diffraction (SAED) and powder X‐ray diffractometry (XRD), we further investigated intensively the internal crystal structure of angled Te NCs and the growth direction of the arms in this study. The experimental results obtained show that the preferential growth direction of either arms in nanocheckmarks is along the [001] direction of trigonal Te, and the corresponding contact plane should be (112) of hexagonal lattice. In the meantime, these results also confirm that L‐cysteine not only can be used as the stabilizer for the synthesis of aqueous CdTe NPs as reported previously, but also can act as a strong complexing agent like EDTA, inducing the decomposition of CdTe NPs, i.e. the transformation from CdTe NPs to Te nanocrystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parallel Crystallization of a “Static” and a Spin‐Crossover Polymorph of an Iron(II) Complex from the Same Solution
Authors: Haryono Marco , Heinemann Frank W. , Petukhov Konstantin , Gieb Klaus , Müller Paul , Grohmann Andreas
Published: April 2009

The ligand 2,6‐bis(1H‐pyrazol‐1‐yl)‐4‐(thiocyanatomethyl)pyridine (L) has been prepared from the hydroxymethyl precursor by OH/Br exchange and subsequent thiocyanate substitution. Two polymorphs of the unsolvated iron(II) complex [Fe(L)2](BF4)2 crystallize at room temperature from the same solution (MeOH), and side by side. One (yellow) is high spin between 4 and 350 K, whereas the other (red‐brown) shows spin crossover, with a thermal spin‐transition centred at 272 K (width ca. 50 K). Both forms have been fully characterized by variable‐temperature structure determination and magnetic susceptibility measurements. At a given temperature, the solid‐state structures differ strongly with respect to the coordination geometry at iron(II), the orientation of the thiocyanatomethyl substituents, and cation‐anion contacts. The implications of these structural differences for the observed spin behaviour are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Nanocapsules by Miniemulsion Polymerization with Biodegradable Surfactant and Hydrophobe
Authors: Romio Ana P. , Sayer Claudia , Araújo Pedro H. H. , Al‐Haydari Mariam , Wu Libo , da Rocha Sandro R. P.
Published: April 2009

Nanocapsules (NCs) are promising candidates for the controlled and targeted delivery of therapeutics in a variety of biomedical applications. In this work we report the formation of NCs by miniemulsion polymerization with renewable, biodegradable, and biocompatible surfactant (lecithin) and hydrophobe (Neobee M5). PMMA was employed as the model (and biocompatible) polymer to synthesize the NCs. Stable dispersions of NCs with sizes between 200–500 nm in diameter and high encapsulation efficiencies were achieved. The effect of the surfactant concentration and mechanical energy input on the size of the parent miniemulsion droplet, and on the resulting NCs was followed by DLS measurements. The final particle morphology was confirmed by SEM and TEM.

magnified image
Fabrication of Polyethylene Superhydrophobic Surfaces by Stretching‐Controlled Micromolding
Authors: Feng Jie , Huang Mingda , Qian Xin
Published: April 2009

This paper describes a novel process that is stretching‐controlled thermal micromolding, to fabricate bionic superhydrophobic polyethylene films. Low‐density polyethylene was thermally pressed in a vacuum oven onto PDMS stamps replicated from lotus leaves. After being cooled and peeled off from the stamps, the polyethylene films with superhydrophobic surface were created, exhibiting a water contact angle of 154.1 ± 3.5° and a rolling angle of ≈7°. SEM imaging showed that the superhydrophobic surface had micro‐papillas much higher than those on the lotus leaf, demonstrating the papillas had been stretched longer from the holes on the stamp during the separating process. This study shows that micromolding is a promising technique for large scale production of superhydrophobic films, even if the holes on the mold are not deep enough.

magnified image
Combating key‐swapping collusion attack on random pairwise key pre‐distribution schemes for wireless sensor networks
Authors: Tran Dai Thanh , Agbinya Johnson I.
Published: April 2009

Random pairwise key pre‐distribution schemes have been adopted extensively as a preferred approach to tackling the pairwise key agreement problem in wireless sensor networks (WSNs). However, their practical applicability is threatened by the key‐swapping collusion attack (KSCA) whose goal is to ruin critical applications that requires collaborative efforts of sensor nodes such as data aggregation mechanisms, routing protocols, distributed voting schemes and misbehaviour detection systems, etc. In this paper, we propose a light‐weight framework for thwarting the attack. Our proposed framework makes good use of a winning combination of incremental sensor node deployment and a diversified one‐way hash chain. The framework thereby evades undesirable costly requirements of additional functionalities and resources to aggregators and base stations, topological knowledge in advance or costly location‐based detection algorithms, yet maintaining network scalability. Moreover, the in‐depth analytical and experimental analyses conducted on two node capture attack models show that the framework eradicates the KSCA under one attack while demonstrating most likely immunity under the other attack. Finally, the detailed performance evaluation carried outviasimulations indicates the plausibility of the framework for use in the current generation of sensor nodes. Copyright © 2009 John Wiley & Sons, Ltd.
Stressors in the intensive care unit: comparing the perceptions of Chinese patients and their family
Authors: Pang Pounds S. K. , Suen Lorna K. P.
Published: April 2009

Admission into an intensive care unit (ICU) is deemed a stressful event by both patients and their families. It has been reported that relatives often have a different perception of the patients' stress levels in comparison with the patients themselves. This study aims to identify stressors in the ICU as perceived by the Chinese patients and their relatives. A convenience sample of 60 patients and 60 relatives was selected for this study. The Intensive Care Unit Stressor Questionnaire [Chinese] was tapped to collect the patients' perceptions of stressors. Their respective relatives were likewise asked to rate the stressors according to how they perceive the patients would rate them. A comparison between the two sets of questionnaires would reveal that the relatives evaluated the items to be more stressful than the actual perception of patients. The overall perceived stress level of ICU patients was significantly lower than their respective relatives' (z = −6.51, p < 0.001), with a mean difference of 44.71 (mean: 61.57 versus 106.28) between the two groups. It is therefore essential that appropriate strategies be implemented to alleviate the stressful feelings perceived by the patients and their families. The influence of cultural beliefs on the perceived stress level of the general Chinese population was likewise highlighted. Copyright © 2008 John Wiley & Sons, Ltd.
The BDNF Val66Met polymorphism impacts parahippocampal and amygdala volume in healthy humans: incremental support for a genetic risk factor for depression
Authors: Montag C. , Weber B. , Fliessbach K. , Elger C. , Reuter M.
Published: April 2009

Background

The role of the brain-derived neurotrophic factor (BDNF) in the pathogenesis of affective disorders such as depression has been controversial. Mounting evidence comes from structural imaging, that the functional BDNF Val66Met polymorphism influences the hippocampal volume with carriers of the 66Met allele (Val/Met and Met/Met group) having smaller hippocampi. Given that stress-induced atrophy of the hippocampus is associated with the pathogenesis of affective disorders, the functional BDNF Val66Met polymorphism could be an incremental risk factor.

Method

Eighty-seven healthy Caucasian participants underwent structural imaging and were genotyped for the BDNF Val66Met polymorphism. Data were analysed by means of voxel-based morphometry (VBM).

Results

Region of interest (ROI) analyses revealed an association between the 66Met allele and smaller parahippocampal volumes and a smaller right amygdala. In addition, the whole-brain analysis showed that the thalamus, fusiformus gyrus and several parts of the frontal gyrus were smaller in 66Met allele carriers.

Conclusions

This study demonstrates that the impact of the BDNF Val66Met polymorphism is not confined to the hippocampus but also extends to the parahippocampal gyrus and the amygdala.
Childhood and adolescent hyperactivity-inattention symptoms and academic achievement 8 years later: the GAZEL Youth study
Authors: Galéra C. , Melchior M. , Chastang J.-F. , Bouvard M.-P. , Fombonne E.
Published: April 2009

Background

Children with attention deficit/hyperactivity disorder (ADHD) are at risk of negative academic outcomes. However, relatively few studies in this area have been based on long-term longitudinal designs and community-based settings. This study examined the link between childhood hyperactivity-inattention symptoms (HI-s) and subsequent academic achievement in a community setting, controlling for other behavioural symptoms, socio-economic status (SES) and environmental factors at baseline.

Method

The sample consisted of 1264 subjects (aged 12 to 26 years at follow-up) recruited from the longitudinal GAZEL Youth study. Psychopathology, environmental variables and academic outcomes were measured through self-reports. Multivariate modelling was performed to evaluate the effects of childhood HI-s and other risk factors on academic achievement 8 years later.

Results

HI-s independently predicted grade retention [adjusted odds ratio (OR) 3.58, 95% confidence interval (CI) 2.38–5.39], failure to graduate from secondary school (adjusted OR 2.41, 95% CI 1.43–4.05), obtaining a lower-level diploma (adjusted OR 3.00, 95% CI 1.84–4.89), and lower academic performance. These results remained significant even after accounting for school difficulties at baseline. Negative academic outcomes were also significantly associated with childhood symptoms of conduct disorder (CD), even after accounting for adjustment variables.

Conclusions

This longitudinal survey replicates, in a general population-based setting, the finding of a link between HI-s and negative academic outcomes.
Short-term post-dispersal fate of seeds defecated by two small primate species (Saguinus mystaxandSaguinus fuscicollis) in the Amazonian forest of Peru
Authors: Culot Laurence , Huynen Marie-Claude , Gérard Paul , Heymann Eckhard W.
Published: April 2009

Post-dispersal fate of seeds dispersed by large primates is well studied but little is known about this process in small frugivores like tamarins. This study in the Amazonian forest of Peru aimed at investigating if characteristics related to the defecation patterns of tamarins (Saguinus mystaxandSaguinus fuscicollis) affected short-term post-dispersal seed fate, through secondary seed dispersal by dung beetles and removal by seed predators. Data on dung beetle activity were based on direct observations of 49 defecations while seed fate was studied using semi-controlled experiments (N = 458 for secondary dispersal and N = 398 for predation). Tamarins produce small defecations with a low number of seeds. Thirty-five per cent of defecations were visited by an average of 1.5 dung beetles that usually transport the faeces as pellets. Twenty-four per cent of seeds were buried by beetles at a mean depth of 3.5 cm. With increasing quantities of faecal matter, the probability of secondary seed dispersal increased but not the depth of burial. Seed predation pressure was low (17.6%) after 4 d and higher in faeces ofS. mystaxthan in faeces ofS. fuscicollis. Despite their small size, tamarins could be considered as high-quality seed dispersers, with a potential role for forest regeneration.
The latrine effect: impact of howler monkeys on the distribution of small seeds in a tropical rain-forest soil
Authors: Pouvelle Sandrine , Jouard Sylvie , Feer François , Tully Thomas , Ponge Jean-François
Published: April 2009

We studied the impact of dung deposition by the red howler monkey (Alouatta seniculus), and subsequent burial by dung beetles and other biotic and abiotic processes, on the distribution of small seeds in the soil seed bank (Nouragues Reserve, French Guiana). Seeds were collected from 54 soil samples taken under three sleeping sites and adjoining control sites, at three positions according to a fixed grid and at three different depths (0–2, 2–4 and 4–6 cm). Despite large differences between the three sites, defecation areas (latrines) were found to contain more seeds and higher seed diversity than control areas. Seed density decreased with depth in the top 6 cm in two sites but not in the third. Shannon diversity decreased with depth in both defecation and control areas. Differences in the distribution of seeds of different species were found according to size and growth habits (pioneer vs non-pioneer species). The viability of seeds, ascertained from toughness and integrity of the seed coat, varied according to depth, site and defecation. Seed viability was on average higher in defecation areas compared with control areas.