bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion
Authors: Eiden Martin , Soto Elizabeth Ortega , Mettenleiter Thomas C , Groschup Martin H
Published: February 2011

In sheep polymorphisms of the prion gene (PRNP) at the codons 136, 154 and 171 strongly influence the susceptibility to scrapie and bovine spongiform encephalopathy (BSE) infections. In goats a number of other gene polymorphisms were found which are suspected to trigger similar effects. However, no strong correlation between polymorphisms and TSE susceptibility in goats has yet been obtained from epidemiological studies and only a low number of experimental challenge data are available at present. We have therefore studied the potential impact of these polymorphisms in vitro by cell-free conversion assays using mouse scrapie strain Me7. Mouse scrapie brain derived PrPSc served as seeds and eleven recombinant single mutation variants of sheep and goat PrPC as conversion targets. With this approach it was possible to assign reduced conversion efficiencies to specific polymorphisms, which are associated to low frequency in scrapie-affected goats or found only in healthy animals. Moreover, we could demonstrate a dominant-negative inhibition of prion polymorphisms associated with high susceptibility by alleles linked to low susceptibility in vitro.
Prevalent de novo somatic mutations in superantigen genes of mouse mammary tumor viruses in the genome of C57BL/6J mice and its potential implication in the immune system
Authors: Lee Young-Kwan , Chiu Sophia , Chew Alex , Greenhalgh David G , Cho Kiho
Published: February 2011

Background

Superantigens (SAgs) of mouse mammary tumor viruses (MMTVs) play a crucial role in T cell selection in the thymus in a T cell receptor (TCR) Vβ-specific manner and SAgs presented by B cells activate T cells in the periphery. The peripheral T cell repertoire is dynamically shaped by the steady induction of T cell tolerance against self antigens throughout the lifespan. We hypothesize thatde novosomatic mutation of endogenous MMTV SAgs contributes to the modulation of the peripheral T cell repertoire.

Results

SAg coding sequences were cloned from the genomic DNAs and/or cDNAs of various tissues of female C57BL/6J mice. A total of 68 unique SAg sequences (54 translated sequences) were identified from the genomic DNAs of liver, lungs, and bone marrow, which are presumed to harbor only three endogenous MMTV loci (Mtv-8,Mtv-9, andMtv-17). Similarly, 69 unique SAg sequences (58 translated sequences) were cloned from the cDNAs of 18 different tissues. Examination of putative TCR Vβ specificity suggested that some of the SAg isoforms identified in this study have Vβ specificities different from the reference SAgs ofMtv-8,Mtv-9, orMtv-17.

Conclusion

The pool of diverse SAg isoforms, generated byde novosomatic mutation, may play a role in the shaping of the peripheral T cell repertoire including the autoimmune T cell population.
Two novel types of hexokinases in the moss Physcomitrella patens
Authors: Nilsson Anders , Olsson Tina , Ulfstedt Mikael , Thelander Mattias , Ronne Hans
Published: February 2011

Background

Hexokinase catalyzes the phosphorylation of glucose and fructose, but it is also involved in sugar sensing in both fungi and plants. We have previously described two types of hexokinases in the mossPhyscomitrella. Type A, exemplified by PpHxk1, the major hexokinase inPhyscomitrella, is a soluble protein that localizes to the chloroplast stroma. Type B, exemplified by PpHxk2, has an N-terminal membrane anchor. Both types are found also in vascular plants, and localize to the chloroplast stroma and mitochondrial membranes, respectively.

Results

We have now characterized all 11 hexokinase encoding genes inPhyscomitrella. Based on their N-terminal sequences and intracellular localizations, three of the encoded proteins are type A hexokinases and four are type B hexokinases. One of the type B hexokinases has a splice variant without a membrane anchor, that localizes to the cytosol and the nucleus. However, we also found two new types of hexokinases with no obvious orthologs in vascular plants. Type C, encoded by a single gene, has neither transit peptide nor membrane anchor, and is found in the cytosol and in the nucleus. Type D hexokinases, encoded by three genes, have membrane anchors and localize to mitochondrial membranes, but their sequences differ from those of the type B hexokinases. Interestingly, all moss hexokinases are more similar to each other in overall sequence than to hexokinases from other plants, even though characteristic sequence motifs such as the membrane anchor of the type B hexokinases are highly conserved between moss and vascular plants, indicating a common origin for hexokinases of the same type.

Conclusions

We conclude that the hexokinase gene family is more diverse inPhyscomitrella, encoding two additional types of hexokinases that are absent in vascular plants. In particular, the presence of a cytosolic and nuclear hexokinase (type C) setsPhyscomitrellaapart from vascular plants, and instead resembles yeast, where all hexokinases localize to the cytosol. The fact that all moss hexokinases are more similar to each other than to hexokinases from vascular plants, even though both type A and type B hexokinases are present in all plants, further suggests that the hexokinase gene family inPhyscomitrellahas undergone concerted evolution.
Evaluating clinic and community-based lifestyle interventions for obesity reduction in a low-income Latino neighborhood: Vivamos Activos Fair Oaks Program
Authors: Drieling Rebecca L , Ma Jun , Stafford Randall S
Published: February 2011

Background

Obesity exerts an enormous health impact through its effect on coronary heart disease and its risk factors. Primary care-based and community-based intensive lifestyle counseling may effectively promote weight loss. There has been limited implementation and evaluation of these strategies, particularly the added benefit of community-based intervention, in low-income Latino populations.

Design

The Vivamos Activos Fair Oaks project is a randomized clinical trial designed to evaluate the clinical and cost-effectiveness of two obesity reduction lifestyle interventions: clinic-based intensive lifestyle counseling, either alone (n = 80) or combined with community health worker support (n = 80), in comparison to usual primary care (n = 40). Clinic-based counseling consists of 15 group and four individual lifestyle counseling sessions provided by health educators targeting behavior change in physical activity and dietary practices. Community health worker support includes seven home visits aimed at practical implementation of weight loss strategies within the person's home and neighborhood. The interventions use a framework based on Social Cognitive Theory, the Transtheoretical Model of behavior change, and techniques from previously tested lifestyle interventions. Application of the framework was culturally tailored based on past interventions in the same community and elsewhere, as well as a community needs and assets assessment. The interventions include a 12-month intensive phase followed by a 12-month maintenance phase. Participants are obese Spanish-speaking adults with at least one cardiovascular risk factor recruited from a community health center in a low-income neighborhood of San Mateo County, California. Follow-up assessments occur at 6, 12, and 24 months for the primary outcome of percent change in body mass index at 24 months. Secondary outcomes include specific cardiovascular risk factors, particularly blood pressure and fasting glucose levels.

Discussion and Conclusions

If successful, this study will provide evidence for broad implementation of obesity interventions in minority populations and guidance about the selection of strategies involving clinic-based case management and community-based community health worker support.

Clinical Trial Registration

ClinicalTrials.gov: NCT01242683
Active protein aggregates induced by terminally attached self-assembling peptide ELK16 in Escherichia coli
Authors: Wu Wei , Xing Lei , Zhou Bihong , Lin Zhanglin
Published: February 2011

Background

In recent years, it has been gradually realized that bacterial inclusion bodies (IBs) could be biologically active. In particular, several proteins including green fluorescent protein, β-galactosidase, β-lactamase, alkaline phosphatase, D-amino acid oxidase, polyphosphate kinase 3, maltodextrin phosphorylase, and sialic acid aldolase have been successfully produced as active IBs when fused to an appropriate partner such as the foot-and-mouth disease virus capsid protein VP1, or the human β-amyloid peptide Aβ42(F19D). As active IBs may have many attractive advantages in enzyme production and industrial applications, it is of considerable interest to explore them further.

Results

In this paper, we report that an ionic self-assembling peptide ELK16 (LELELKLK)2 was able to effectively induce the formation of cytoplasmic inclusion bodies in Escherichia coli (E. coli) when attached to the carboxyl termini of four model proteins including lipase A, amadoriase II, β-xylosidase, and green fluorescent protein. These aggregates had a general appearance similar to the usually reported cytoplasmic inclusion bodies (IBs) under transmission electron microscopy or fluorescence confocal microscopy. Except for lipase A-ELK16 fusion, the three other fusion protein aggregates retained comparable specific activities with the native counterparts. Conformational analyses by Fourier transform infrared spectroscopy revealed the existence of newly formed antiparallel beta-sheet structures in these ELK16 peptide-induced inclusion bodies, which is consistent with the reported assembly of the ELK16 peptide.

Conclusions

This has been the first report where a terminally attached self-assembling β peptide ELK16 can promote the formation of active inclusion bodies or active protein aggregates in E. coli. It has the potential to render E. coli and other recombinant hosts more efficient as microbial cell factories for protein production. Our observation might also provide hints for protein aggregation-related diseases.
Immunization with different Pf AMA1 alleles in sequence induces clonal imprint humoral responses that are similar to responses induced by the same alleles as a vaccine cocktail in rabbits
Authors: Kusi Kwadwo A , Faber Bart W , van der Eijk Marjolein , Thomas Alan W , Kocken Clemens HM , Remarque Edmond J
Published: February 2011

Background

Antibodies to key Plasmodium falciparum surface antigens have been shown to be important effectors that mediate clinical immunity to malaria. The cross-strain fraction of anti-malarial antibodies may however be required to achieve

strain-transcending immunity. Such antibody responses against Plasmodium falciparum apical membrane antigen 1 (Pf AMA1), a vaccine target molecule that is expressed in both liver and blood stages of the parasite, can be elicited through immunization with a mixture of allelic variants of the parasite molecule. Cross-strain antibodies are most likely elicited against epitopes that are shared by the allelic antigens in the vaccine cocktail.

Methods

A standard competition ELISA was used to address whether the antibody response can be further focused on shared epitopes by exclusively boosting these common determinants through immunization of rabbits with different Pf AMA1 alleles in sequence. The in vitro parasite growth inhibition assay was used to further evaluate the functional effects of the broadened antibody response that is characteristic of multi-allele vaccine strategies.

Results

A mixed antigen immunization protocol elicited humoral responses that were functionally similar to those elicited by a sequential immunization protocol (p > 0.05). Sequential exposure to the different Pf AMA1 allelic variants induced immunological recall of responses to previous alleles and yielded functional cross-strain antibodies that would be capable of optimal growth inhibition of variant parasites at high enough concentrations.

Conclusions

These findings may have implications for the current understanding of the natural acquisition of clinical immunity to malaria as well as for rational vaccine design.
Developing a method to derive alcohol-attributable fractions for HIV/AIDS mortality based on alcohol's impact on adherence to antiretroviral medication
Authors: Gmel Gerrit , Shield Kevin D , Rehm Jürgen
Published: February 2011

Background

Alcohol consumption is causally linked to nonadherence to antiretroviral treatment that in turn causes an increase in HIV/AIDS mortality. This article presents a method to calculate the percentage of HIV/AIDS deaths attributable to alcohol consumption and the associated uncertainty.

Methods

By combining information on risk relations from a number of published sources, we estimated alcohol-attributable fractions (AAFs) of HIV/AIDS in a stepwise procedure. First, we estimated the effect of alcohol consumption on adherence to antiretroviral treatment, and then we combined this estimate with the impact of nonadherence on death. The 95% uncertainty intervals were computed by estimating the variance of the AAFs using Taylor series expansions of one and multiple variables. AAFs were determined for each of the five Global Burden of Disease regions of Africa, based on country-specific treatment and alcohol consumption data from 2005.

Results

The effects of alcohol on HIV/AIDS in the African Global Burden of Disease regions range from 0.03% to 0.34% for men and from 0% to 0.17% for women, depending on region and age category. The detrimental effect of alcohol consumption was statistically significant in every region and age category except for the North Africa/Middle East region.

Conclusions

Although the method has its limitations, it was shown to be feasible and provided estimates of the impact of alcohol use on the mortality outcome of HIV/AIDS.
Single-crystalline nanoporous Nb2O5 nanotubes
Authors: Liu Jun , Xue Dongfeng , Li Keyan
Published: February 2011

Single-crystalline nanoporous Nb2O5 nanotubes were fabricated by a two-step solution route, the growth of uniform single-crystalline Nb2O5 nanorods and the following ion-assisted selective dissolution along the [001] direction. Nb2O5 tubular structure was created by preferentially etching (001) crystallographic planes, which has a nearly homogeneous diameter and length. Dense nanopores with the diameters of several nanometers were created on the shell of Nb2O5 tubular structures, which can also retain the crystallographic orientation of Nb2O5 precursor nanorods. The present chemical etching strategy is versatile and can be extended to different-sized nanorod precursors. Furthermore, these as-obtained nanorod precursors and nanotube products can also be used as template for the fabrication of 1 D nanostructured niobates, such as LiNbO3, NaNbO3, and KNbO3.
Scanning tip measurement for identification of point defects
Authors: Dózsa László , Molnár György , Raineri Vito , Giannazzo Filippo , Ferencz János , Lányi Štefan
Published: February 2011

Self-assembled iron-silicide nanostructures were prepared by reactive deposition epitaxy of Fe onto silicon. Capacitance-voltage, current-voltage, and deep level transient spectroscopy (DLTS) were used to measure the electrical properties of Au/silicon Schottky junctions. Spreading resistance and scanning probe capacitance microscopy (SCM) were applied to measure local electrical properties. Using a preamplifier the sensitivity of DLTS was increased satisfactorily to measure transients of the scanning tip semiconductor junction. In the Fe-deposited area, Fe-related defects dominate the surface layer in about 0.5 μm depth. These defects deteriorated the Schottky junction characteristic. Outside the Fe-deposited area, Fe-related defect concentration was identified in a thin layer near the surface. The defect transients in this area were measured both in macroscopic Schottky junctions and by scanning tip DLTS and were detected by bias modulation frequency dependence in SCM.
Myocardial post-conditioning with Danshen-Gegen decoction protects against isoproterenol-induced myocardial injury via a PKCε/mKATP-mediated pathway in rats
Authors: Wong Sze Man , Chiu Po Yee , Leung Hoi Yan , Zhou Limin , Zuo Zhong , Lam Philip Y , Ko Kam Ming
Published: February 2011

Background

Danshen-Gegen decoction (DG), a Chinese herbal formula, has been demonstrated to be effective for the treatment of coronary heart disease such as myocardial infarction. In the present study, we investigated the effect of DG post-conditioning on isoproterenol (ISO)-induced myocardial injury in rats.

Methods

ISO was injected intraperitoneally (200 mg/kg) to induce acute (2-6 hours) myocardial injury in adult female rats. DG (4 g/kg) was administered per oral immediately after the injection of ISO in the rats. Extent of myocardial injury was assessed by measurements of plasma enzyme activities. Myocardial mitochondrial glutathione antioxidant status, lipid peroxidation and mitochondrial calcium ion loading and cytochrome c release were also measured. Effects of inhibitors of protein kinase C-epsilon (PKCε) ranslocation and mitochondrial ATP-sensitive potassium channel (mKATP) on myocardial post-conditioning by DG were investigated.

Results

ISO inflicted acute myocardial injury in the rats as evidenced by increased plasma enzyme activities. DG post-treatment alleviated the ISO-induced acute myocardial injury.

Conclusion

DG post-treatment protected the myocardium against ISO-induced acute injury in rats. The myocardial post-conditioning by DG is likely mediated by PKCε/mKATP signaling pathway.
Benign giant mediastinal schwannoma presenting as cardiac tamponade in a woman: a case report
Authors: Kato Motoyasu , Shiota Satomi , Shiga Kazuo , Takagi Haruhi , Mori Hiroaki , Sekiya Mitsuaki , Suzuki Kenji , Uekusa Toshimasa , Takahashi Kazuhisa
Published: February 2011

Introduction

Mediastinal schwannomas are typically benign and asymptomatic, and generally present no immediate risks. We encountered a rare case of a giant benign posterior mediastinal schwannoma, complicated by life-threatening cardiac tamponade.

Case presentation

We report the case of a 72-year-old Japanese woman, who presented with cardiogenic shock. Computed tomography of the chest revealed a posterior mediastinal mass 150 cm in diameter, with pericardial effusion. The cardiac tamponade was treated with prompt pericardial fluid drainage. A biopsy was taken from the mass, and after histological examination, it was diagnosed as a benign schwannoma, a well-encapsulated non-infiltrating tumor, originating from the intrathoracic vagus nerve. It was successfully excised, restoring normal cardiac function.

Conclusion

Our case suggests that giant mediastinal schwannomas, although generally benign and asymptomatic, should be excised upon discovery to prevent the development of life-threatening cardiopulmonary complications.
An unusual case of persistent groin pain after total hip arthroplasty: a case report
Authors: Konala Praveen , Schaefer Thomas K , Iranpour Farhad , Friederich Niklaus F , Hirschmann Michael T
Published: February 2011

Introduction

Arthroplasty is a well-established routine elective surgical procedure in orthopaedics. To a great extent, diagnosis, treatment and post-operative rehabilitation in these patients is standardised. In a busy clinic, surgeons from time to time tend to focus their attention on common causes of joint pain, but it may lead them to overlook sinister but less common pathologies. Here we report a case of a patient with groin pain due to pre-operatively undetected pelvic metastases from a pyeloureteral carcinoma who underwent total hip arthroplasty. There are several case reports which deal with primary or secondary tumours which were either discovered at the time of replacement surgery or developed at the site of prosthesis years after total hip or knee replacement. To the best of our knowledge, this is the first case report in which a metastatic cancer was missed pre-operatively and intra-operatively both by the radiologist and by the orthopaedic surgeon and should be reported so that surgeons are reminded to be careful when dealing with seemingly routine cases.

Case presentation

A 79-year-old Caucasian woman presented to the arthroplasty clinic with groin pain. Initial radiographs showed subtle bilateral abnormalities in the pelvis. Neither the radiologist nor the orthopaedic surgeon recognized it. A diagnosis of osteoarthritis of the hip was established, and she underwent total hip arthroplasty. Despite initial improvement, the patient came back with worsening hip pain three months later. Further radiological examination revealed multiple metastatic lesions throughout the pelvis due to a pyeloureteral carcinoma.

Conclusions

This case report emphasizes the importance of meticulous, unbiased pre-operative assessment of patients and their radiographs, even in so-called routine clinical cases. Often subtle radiological changes are classed as normal, especially if they are bilateral. Further radiological imaging should be recommended in all cases where unexplained clinical features or radiological findings are present.
Antibiotic prescriptions in primary health care in a rural population in Crete, Greece
Authors: Kontarakis Nikolaos , Tsiligianni Ioanna G , Papadokostakis Polyvios , Giannopoulou Evangelia , Tsironis Loukas , Moustakis Vasilios
Published: February 2011

Background

Antibiotic over-prescribing has generally been considered to be common in Greece, however not much is known about current antibiotic use.

Findings

The aim of this study was to investigate antibiotic prescribing in a well-defined rural population of 159 adults and 99 children over a 12-month period in Crete, Greece. The daily-defined doses (DDD) for 1000 people/day (DID) were 22.1 and 24.2 for children and adults respectively. The overall DID was 23.4, markedly lower than that previously reported for Greece. The use of penicillins was 49.5% of DDD in children and 31.7% in adults. Quinolones represented 2.2% of the total antibiotics (0% in children). Prescriptions of antibiotics were more common during the 3-month period from January to March for both children and adults.

Conclusions

The findings of this study confirm the seasonal distribution of antibiotics used and the predominance of prescribing for respiratory tract infections. In the area of the study, antibiotic use seems to be lower than that previously reported for Greece, probably as a result of the recently established net of well-trained primary health physicians.
Characterization of a synthetic human LINE-1 retrotransposon ORFeus-Hs
Authors: An Wenfeng , Dai Lixin , Niewiadomska Anna Maria , Yetil Alper , O'Donnell Kathryn A , Han Jeffrey S , Boeke Jef D
Published: February 2011

Long interspersed elements, type 1(LINE-1, L1) are the most abundant and only active autonomous retrotransposons in the human genome. Native L1 elements are inefficiently expressed because of a transcription elongation defect thought to be caused by high adenosine content in L1 sequences. Previously, we constructed a highly active synthetic mouse L1 element (ORFeus-Mm), partially by reducing the nucleotide composition bias. As a result, the transcript abundance of ORFeus-Mm was greatly increased, and its retrotransposition frequency was > 200-fold higher than its native counterpart. In this paper, we report a synthetic human L1 element (ORFeus-Hs) synthesized using a similar strategy. The adenosine content of the L1 open reading frames (ORFs) was reduced from 40% to 27% by changing 25% of the bases in the ORFs, without altering the amino acid sequence. By studying a series of native/synthetic chimeric elements, we observed increased levels of full-length L1 RNA and ORF1 protein and retrotransposition frequency, mostly proportional to increased fraction of synthetic sequence. Overall, the fully synthetic ORFeus-Hs has > 40-fold more RNA but is at most only ~threefold more active than its native counterpart (L1RP); however, its absolute retrotransposition activity is similar to ORFeus-Mm. Owing to the elevated expression of the L1 RNA/protein and its high retrotransposition ability, ORFeus-Hs and its chimeric derivatives will be useful tools for mechanistic L1 studies and mammalian genome manipulation.
Analyses Adjusting for Selective Crossover Show Improved Overall Survival With Adjuvant Letrozole Compared With Tamoxifen in the BIG 1-98 Study
Authors: Colleoni Marco , Giobbie-Hurder Anita , Regan Meredith M. , Thürlimann Beat , Mouridsen Henning , Mauriac Louis , Forbes John F. , Paridaens Robert , Láng István , Smith Ian , Chirgwin Jacquie , Pienkowski Tadeusz , Wardley Andrew , Price Karen N. , Gelber Richard D. , Coates Alan S. , Goldhirsch Aron
Published: February 2011

Purpose

Among postmenopausal women with endocrine-responsive breast cancer, the aromatase inhibitor letrozole, when compared with tamoxifen, has been shown to significantly improve disease-free survival (DFS) and time to distant recurrence (TDR). We investigated whether letrozole monotherapy prolonged overall survival (OS) compared with tamoxifen monotherapy.

Patients and Methods

Of 8,010 postmenopausal women with hormone receptor–positive, early breast cancer enrolled on the Breast International Group (BIG) 1-98 study, 4,922 were randomly assigned to 5 years of continuous adjuvant therapy with either letrozole or tamoxifen. Of 2,459 patients enrolled in the tamoxifen treatment arm, 619 (25.2%) selectively crossed over to either adjuvant or extended letrozole after initial trial results were presented in January 2005. To gain better estimates of relative treatment effects in the presence of selective crossover, we used inverse probability of censoring weighted (IPCW) modeling.

Results

Weighted Cox models, by using IPCW, estimated a statistically significant, 18% reduction in the hazard of an OS event with letrozole treatment (hazard ratio [HR], 0.82; 95% CI, 0.70 to 0.95). Estimates of 5-year OS on the basis of IPCW were 91.8% and 90.4% for letrozole and tamoxifen, respectively. The HRs of DFS and TDR events by using IPCW modeling were 0.83 (95% CI, 0.74 to 0.94) and 0.80 (95% CI, 0.67 to 0.94), respectively (P < .05 for DFS, OS, and TDR). Median follow-up was 74 months.

Conclusion

Adjuvant treatment with letrozole, compared with tamoxifen, significantly reduces the risk of death, the risk of recurrent disease, and the risk of recurrence at distant sites in postmenopausal women with hormone receptor–positive breast cancer.
A distinct trans-Golgi network subcompartment for sorting of synaptic and granule proteins in neurons and neuroendocrine cells
Authors: Park Joshua J. , Gondré-Lewis Marjorie C. , Eiden Lee E. , Loh Y. Peng
Published: February 2011

Golgi-to-plasma-membrane trafficking of synaptic-like microvesicle (SLMV) proteins, vesicular acetylcholine transporter (VAChT) and synaptophysin (SYN), and a large dense-core vesicle (LDCV) protein, chromogranin A (CgA), was investigated in undifferentiated neuroendocrine PC12 cells. Live cell imaging and 20°C block–release experiments showed that VAChT–GFP, SYN–GFP and CgA–RFP specifically and transiently cohabitated in a distinct sorting compartment during cold block and then separated into synaptic protein transport vesicles (SPTVs) and LDCVs, after release from temperature block. We found that in this trans-Golgi subcompartment there was colocalization of SPTV and LDCV proteins, most significantly with VAMP4 and Golgin97, and to some degree with TGN46, but not at all with TGN38. Moreover, some SNAP25 and VAMP2, two subunits of the exocytic machinery, were also recruited onto this compartment. Thus, in neuroendocrine cells, synaptic vesicle and LDCV proteins converge briefly in a distinct trans-Golgi network subcompartment before sorting into SPTVs and LDCVs, ultimately for delivery to the plasma membrane. This specialized sorting compartment from which SPTVs and LDCVs bud might facilitate the acquisition of common exocytic machinery needed on the membranes of these vesicles.
Comparison and assessment of a hydraulic energy-saving system for hydrostatic drives
Authors: Triet H H , Ahn K K
Published: February 2011

A novel hydraulic energy-saving system for hydrostatic drives using flywheels as energy storage systems is proposed in this paper. The system has been developed based on a traditional closed-loop hydrostatic transmission (HST) with novel energy storage, including a hydraulic accumulator and a flywheel. The control strategy for the proposed system has also been designed. Mathematical modelling, simulation, and experimentation in the test rig have been performed in this study. The experimental results implied that the proposed system could be applied for mobile applications. The study confirmed that the system saved 48 per cent energy supplied from the primary power source when compared with a traditional HST for modified ten-mode profile.
A new non-fragile H∞ proportional—integral filtered-error adaptive observer for a class of non-linear systems and its application to synchronous generators
Authors: Pourgholi M , Majd V J
Published: February 2011

In this paper, a parameter and state estimation problem in the presence of observer gain perturbations and input disturbance is discussed for the Lipschitz systems that are linear in unknown parameters and non-linear in states. A non-linear non-fragile proportional—integral filtered-error adaptive observer is designed, and its stability conditions based on the Lyapunov technique are derived. The optimal gain among a solution set that satisfies the observer stability conditions is derived systematically using the linear matrix inequality approach. Numerical examples, as well as a synchronous generator case study, are provided in which the non-linear terms depend on the unmeasured states. The proposed design is more robust against both disturbance and gain perturbations than those presented in recent research. Moreover, it is feasible for much larger values of the Lipschitz constants than is the case for conventional methods.
Non-linear modelling and compound intelligent control of pulsed gas tungsten arc welding dynamics
Authors: Chen S B , Wu J , Du Q Y
Published: February 2011

Gas tungsten arc welding (GTAW) dynamics is a highly complicated process with strong non-linearity, time variability, multiple interference, and uncertainty. The present paper uses a non-linear Hammerstein model to describe the welding process. Based on the model, a compound intelligent controller integrating a non-linear self-tuning controller with a fuzzy logic controller is developed to regulate the welding process. Welding experiments have been conducted and verify that the proposed controller has faster response speed and steadier weld-seam formation.
New global exponential stability criteria for interval-delayed neural networks
Authors: Su X , Li Z , Feng Y , Wu L
Published: February 2011

This paper is concerned with the problem of global robust exponential stability analysis for a class of interval cellular neural networks with time delay. By introducing a novel Lyapunov-Krasovslii function combined with the idea of delay fractioning, some delay-dependent conditions are derived in terms of the linear matrix inequality, which guarantee the considered interval delayed cellular neural networks to be globally exponentially stable. Moreover, the conservatism can be notably reduced as the fractioning becomes thinner. Some numerical examples are provided to demonstrate the advantages of the proposed results.
Virtual force field algorithm for a behaviour-based autonomous robot in unknown environments
Authors: Nia D Nakhaei , Tang H S , Karasfi B , Motlagh O R E , Kit A C
Published: February 2011

The present paper describes a real-time motion-planning approach which lies in the integration of three techniques: fuzzy logic (FL), virtual force field (VFF), and boundary following (BF). The FL algorithm is used for velocity control based on sonar readings. The path-planning algorithm is based on the VFF and BF methods. The proposed navigation system differs from previous works in terms of using different algorithms for planning robot motion. Other improvements concern functional and computational aspects of the design and integration of the modules. The robot shows robust performance in complex situations and local minimum scenarios. Simulation results show the effectiveness of the developed system in various environments with long walls, U-shaped, maze-like, and other types of clutter.
A robust in vivo positive-readout system for monitoring siRNA delivery to xenograft tumors
Authors: Lin Xiaoyu , Li Leiming , Wang Rongqi , Wilcox Denise , Zhao Xiaobin , Song Jingfeng , Huang Xiaoli , Hansen T. Matthew , Dande Prasad , Wada Carol , Hubbard Robert D. , Kohlbrenner William M. , Fesik Stephen W. , Shen Yu
Published: February 2011

Delivering small interfering RNA (siRNA) to tumors is the major technical hurdle that prevents the advancement of siRNA-based cancer therapy. One of the difficulties associated with the development of clinically relevant delivery systems is the lack of reliable tools for monitoring siRNA delivery to tumors in vivo. We describe here a novel, positive-readout system where siRNA-mediated target knockdown elicits a rapid and robust increase of reporter activity. Using the positive-readout system, we created (1) β-galactosidase-based tumor models that allow the detection of target knockdown in 1%–2% of tumor cells and can distinguish between tumor areas where effective target knockdown occurs versus tumor areas that are not accessible to delivery, and (2) luciferase-based tumor models that allow the quantitative assessment of a large number of delivery systems. Using these positive-readout models, we screened a number of literature-described siRNA delivery systems and identified lipid nanoparticles as a promising delivery platform for siRNA-based cancer therapy.
Determinants and Outcomes of Internet Banking Adoption
Authors: Xue Mei , Hitt Lorin M. , Chen Pei-yu
Published: February 2011

This paper examines the drivers of adoption of Internet banking and the linkages among adoption drivers and outcomes (product acquisition, service activity, profitability, loyalty). We relate Internet banking adoption to customer demand for banking services, the availability of alternative channels, customers' efficiency in service coproduction (“customer efficiency”), and local Internet banking penetration. We find that customers who have greater transaction demand and higher efficiency, and reside in areas with a greater density of online banking adopters, are faster to adopt online banking after controlling for time, regional, and individual characteristics. Consistent with prior work, we find that customers significantly increase their banking activity, acquire more products, and perform more transactions. These changes in behavior are not associated with short-run increases in customer profitability, but customers who adopt online banking have a lower propensity to leave the bank. Building on these observations we also find that the adoption drivers are linked to the postadoption changes in behavior or profitability. Customers who live in areas with a high branch density or high Internet banking penetration increase their product acquisition and transaction activity more than Internet banking adopters in other regions. Efficient customers and those with high service demand show greater postadoption profitability.

This paper was accepted by Sandra Slaughter, information systems.
CROSSROADS—The Atlantic Divide: American and European Approaches to Strategy Research
Authors: Shapira Zur
Published: February 2011

Unlike most of the social sciences, the field of strategy originated in the United States and arrived in Europe later. Did this trajectory lead to an “Atlantic divide” in strategy research? Does such a divide exist? The papers that follow debate the issue and the effects that such a potential divide may have on the growth of the field.
The Dynamics of the Performance–Risk Relationship Within a Performance Period: The Moderating Role of Deadline Proximity
Authors: Lehman David W. , Hahn Jungpil , Ramanujam Rangaraj , Alge Bradley J.
Published: February 2011

Risky organizational decisions are frequently made within the confines of performance periods with predefined durations and deadlines for achieving desired levels of performance. The relationship between performance and risk taking has been studied mostly across such periods but rarely within them. Building on the shifting-focus-of-attention model of organizational risk taking, we argue that the temporal proximity of deadlines regulates the focus of organizational attention within a performance period. Decision makers will focus their attention on attaining and maintaining aspirations early in a period; however, as deadlines approach, decision makers in underperforming firms will increasingly be likely to focus on ensuring survival, whereas decision makers in outperforming firms will increasingly be likely to focus on experimenting with slack resources. We propose that the relationship between performance and risk taking should thus be moderated by deadline proximity within a performance period. We tested and found support for our hypotheses in the context of 22,603 fourth-down decisions made by the 32 National Football League teams during the 2000–2005 regular season games. Our findings suggest that the notion of temporally bound performance periods and deadline proximity should play a more central role in attention-based frameworks of organizational risk taking.
Feeding ecology, habitat use and reproduction of Rousettus madagascariensis Grandidier, 1928 (Chiroptera: Pteropodidae) in eastern Madagascar
Authors: Andrianaivoarivelo Radosoa A. , Ramilijaona Olga R. , Racey Paul A. , Razafindrakoto Noromampiandra , Jenkins Richard K.B.
Published: February 2011

We studied the diet, habitat use and biology of Rousettus madagascariensis, a relatively small (∼55–77 g) fruit bat endemic to Madagascar, between July 2004 and May 2005. Faecal analysis revealed few seeds in the diet, suggesting that the bats either feed extensively on nectar, flowers and leaves or on fruits with seeds too large to ingest. However, bats were captured near fruiting Ficus sp. inside relatively intact forest and Ficus sp. seeds were found in the faeces during March and April. Defecated Ficus rubra seeds germinated significantly faster than seeds from ripe fruits under controlled conditions, but germination rates were similar. Radio tracking and observations of light-tagged individuals revealed that R. madagascariensis travelled a straight line distance of at least 8 km between the roost and feeding locations, with round trip foraging routes of up to 27 km. Most juveniles were trapped between March and July and we infer that weaning of young started before 8 weeks of age. The features used to distinguish juveniles from adults were no longer evident in December and it appears therefore that R. madagascariensis reaches somatic maturity within a single year. Pregnancy, lactation and weaning in this species coincide with the austral summer when food availability is higher.
Reinstatement of Barbastella (Chiroptera, Vespertilionidae) and Eothenomys (Rodentia, Cricetidae) to the Lao fauna
Authors: Duckworth J.W. , Pons Jean-Marc
Published: February 2011

No abstract available
Suppression of the C/EBP family of transcription factors in adipose tissue causes lipodystrophy
Authors: Chatterjee Raghunath , Bhattacharya Paramita , Gavrilova Oksana , Glass Kimberly , Moitra Jaideep , Myakishev Max , Pack Stephanie , Jou William , Feigenbaum Lionel , Eckhaus Michael , Vinson Charles
Published: February 2011

Adipose-specific inactivation of both AP-1 and CCAAT-enhancer-binding protein (C/EBP) families of B-ZIP transcription factors in transgenic mice causes severe lipoatrophy. To evaluate whether inactivation of only C/EBP members was critical for lipoatrophy, A-C/EBP, a dominant-negative protein that specifically inhibits the DNA binding of the C/EBP members, was expressed in adipose tissue. For the first 2 weeks after birth, aP2-A-C/EBP mice had no white adipose tissue (WAT), drastically reduced brown adipose tissue (BAT), and exhibited marked hepatic steatosis, hyperinsulinemia, and hyperlipidemia. However, WAT appeared during the third week, coinciding with significantly improved metabolic functioning. In adults, BAT remained reduced, causing cold intolerance. At 30 weeks, the aP2-A-C/EBP mice had only 35% reduced WAT, with clear morphological signs of lipodystrophy in subcutaneous fat. Circulating leptin and adiponectin levels were less than the wild-type levels, and these mice exhibited impaired triglyceride clearance. Insulin resistance, glucose intolerance, and reduced free fatty acid release in response to β3-adrenergic agonist suggest improper functioning of the residual WAT. Gene expression analysis of inguinal WAT identified reduced mRNA levels of several enzymes involved in fatty acid synthesis and glucose metabolism that are known C/EBPα transcriptional targets. There were increased levels for genes involved in inflammation and muscle differentiation. However, when dermal fibroblasts from aP2-A-C/EBP mice were differentiated into adipocytes in tissue culture, muscle markers were elevated more than the inflammatory markers. These results demonstrate that the C/EBP family is essential for adipose tissue development during the early postnatal period, the regulation of glucose and lipid homeostasis in adults, and the suppression of the muscle lineage.
Late Preterm Infants Have Worse 24-Month Neurodevelopmental Outcomes Than Term Infants
Authors: Woythaler Melissa A. , McCormick Marie C. , Smith Vincent C.
Published: February 2011

BACKGROUND:

Late preterm infants (34–37 weeks' gestation) are often perceived at similar risks for morbidity and mortality as term infants.

OBJECTIVE:

To compare the neurodevelopmental outcomes of late preterm to term infants.

METHODS:

Our study sample of 6300 term and 1200 late preterm infants came from the Early Childhood Longitudinal Study-Birth Cohort. We used general estimating equations to get weighted odds of having developmental delay, mental index scores (MDI) or psychomotor index scores (PDI) < 70, at 24 months of age.

RESULTS:

Late preterm infants compared with term infants had lower MDI (85 vs 89) and PDI (88 vs 92), both P < .0001, respectively. A higher proportion of late preterm infants compared with term infants had an MDI <70 (21% vs 16%; P < .0001). An equal number had PDIs <70 (6.1% vs 6.5%). After controlling for statistically significant and clinically relevant descriptive characteristics, late preterm infants still had higher odds of mental (odds ratio: 1.52 [95% confidence interval: 1.26–1.82] P < .0001) or physical (odds ratio: 1.56 [95% confidence interval: 1.30–1.89] P < .0001) developmental delay.

CONCLUSIONS:

Late preterm infants have poorer neurodevelopmental outcomes than term infants and have increased odds to have a mental and/or physical developmental delay.
Increased Enoxaparin Dosing Is Required for Obese Children
Authors: Lewis Teresa V. , Johnson Peter N. , Nebbia Ashley M. , Dunlap Marny
Published: February 2011

Weight-based dosing for enoxaparin is recommended in the 2008 American College of Chest Physicians (ACCP) guidelines for venous thromboembolism (VTE) prophylaxis. Enoxaparin 0.5 mg/kg per dose administered subcutaneously every 12 hours is recommended for this indication in children. There is no established upper dosing limit of enoxaparin for prophylaxis in children, and the US Food and Drug Administration–approved enoxaparin dose for adults for VTE prophylaxis is 30 mg subcutaneously every 12 hours or 40 mg subcutaneously daily. Therefore, we assumed that the upper limit for children is 40 mg subcutaneously daily. We reviewed 3 cases of obese adolescent boys who required large doses of enoxaparin to achieve the ACCP-recommended anti-factor Xa range of 0.1 to 0.3 IU/mL for the prevention of VTE. All 3 patients required doses of enoxaparin that are higher than that recommended for adults for VTE prophylaxis: patient A (BMI: 105.9) required >0.28 mg/kg per dose, patient B (BMI: 95.7) required 0.15 mg/kg per dose, and patient C (BMI: 29.9) required 0.49 mg/kg per dose. The desired anti-factor Xa range was achieved when enoxaparin was administered every 12 hours in each patient with no reported episodes of VTE. One patient had minor bruising, but no other adverse events were noted. Because of the variability in dose requirements and unpredictability in patient responses demonstrated in our 3 adolescents, prospective studies are needed to provide definitive recommendations on dosing of enoxaparin for VTE prophylaxis in this subset of obese pediatric patients.
Ambulatory Visit Rates and Antibiotic Prescribing for Children With Pneumonia, 1994–2007
Authors: Kronman Matthew P. , Hersh Adam L. , Feng Rui , Huang Yuan-Shung , Lee Grace E. , Shah Samir S.
Published: February 2011

BACKGROUND:

The incidence of pediatric hospitalizations for community-acquired pneumonia (CAP) has declined after the widespread use of the heptavalent pneumococcal conjugate vaccine. The national incidence of outpatient visits for CAP, however, is not well established. Although no pediatric CAP treatment guidelines are available, current data support narrow-spectrum antibiotics as the first-line treatment for most patients with CAP.

OBJECTIVE:

To estimate the incidence rates of outpatient CAP, examine time trends in antibiotics prescribed for CAP, and determine factors associated with broad-spectrum antibiotic prescribing for CAP.

PATIENTS AND METHODS:

The National Ambulatory and National Hospital Ambulatory Medical Care Surveys (1994–2007) were used to identify children aged 1 to 18 years with CAP using a validated algorithm. We determined age group–specific rates of outpatient CAP and examined trends in antibiotic prescribing for CAP. Data from 2006–2007 were used to study factors associated with broad-spectrum antibiotic prescribing.

RESULTS:

Overall, annual CAP visit rates ranged from 16.9 to 22.4 per 1000 population, with the highest rates occurring in children aged 1 to 5 years (range: 32.3–49.6 per 1000). Ambulatory CAP visit rates did not change between 1994 and 2007. Antibiotics commonly prescribed for CAP included macrolides (34% of patients overall), cephalosporins (22% overall), and penicillins (14% overall). Cephalosporin use increased significantly between 2000 and 2007 (P = .002). Increasing age, a visit to a nonemergency department office, and obtaining a radiograph or complete blood count were associated with broad-spectrum antibiotic prescribing.

CONCLUSIONS:

The incidence of pediatric ambulatory CAP visits has not changed significantly between 1994 and 2007, despite the introduction of heptavalent pneumococcal conjugate vaccine in 2000. Broad-spectrum antibiotics, particularly macrolides, were frequently prescribed despite evidence that they provide little benefit over penicillins.