bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of compliant anthropomimetic robot joint
Authors: Svetozarevic Bratislav , Jovanovic Kosta
Published: October 2011

In this paper we propose a control strategy for a robot joint which fully mimics the typical human joint structure. The joint drive is based on two actuators (dc motors), agonist and antagonist, acting through compliant tendons and forming a nonlinear multi-input multi-output (MIMO) system. At any time, we consider one actuator, the puller, as being responsible for motion control, while the role of the other is to keep its tendon force at some appropriate low level. This human-like and energetically efficient approach requires the control of 'switching', or exchanging roles between actuators. Moreover, an algorithm based on adaptive force reference is used to solve a problem of slacken tendons during the switching and to increase the energy efficiency. This approach was developed and evaluated on increasingly complex robot joint configurations, starting with simple and noncompliant system, and finishing with nonlinear and compliant system.
Control of multi-machine using adaptive fuzzy
Authors: Bouchiba Bousmaha , Hazzab Abdeldjebar , Glaoui Hachemi , Med-Karim Fellah , Bousserhane Ismaïl , Sicard Pierre
Published: October 2011

An indirect Adaptive fuzzy excitation control (IAFLC) of power systems based on multi-input-multi-output linearization technique is developed in this paper. The power system considered in this paper consists of two generators and infinite bus connected through a network of transformers and transmission lines. The fuzzy controller is constructed from fuzzy feedback linearization controller whose parameters are adjusted indirectly from the estimates of plant parameters. The adaptation law adjusts the controller parameters on-line so that the plant output tracks the reference model output. Simulation results shown that the proposed controller IAFLC, compared with a controller based on tradition linearization technique can enhance the transient stability of the power system.
Numerical analysis of relative phase and amplitude at the interaction two solitons in optical fibers
Authors: Jaksic Branimir , Stefanovic Mihajlo , Spalevic Petar , Savic Ana , Bogdanovic Radoslav
Published: October 2011

In this paper presented the analysis propagation solitons pair in optical fiber from the standpoint of relative amplitude and relative phase. Consider the influence of changes relative phase and amplitude in the interaction of two solitons in optical fibers. Shows the simulation (in the space-time domain) of movement solitons pairs in optical fiber with the change of these two parameters.
Deep brain stimulation of the subthalamic nucleus for advanced Parkinson disease using general anesthesia: long-term results
Authors: Harries Anwen M. , Kausar Jamilla , Roberts Stuart A. G. , Mocroft A. Paul , Hodson James A. , Pall Hardev S. , Mitchell Rosalind D.
Published: October 2011

Object

The authors analyze long-term outcome in a substantial number of patients who underwent subthalamic nucleus (STN) deep brain stimulation (DBS) surgery under general anesthesia.

Methods

Eighty-two patients underwent bilateral placement of DBS electrodes under general anesthesia for advanced Parkinson disease; the STN was the target in all cases. All patients underwent intraoperative microelectrode recording of the STN. No intraoperative macrostimulation was performed. Unified Parkinson's Disease Rating Scale (UPDRS) data were recorded in 28 patients. Assessment of outcome was performed using the UPDRS (in 28 cases), the electrophysiological recordings (in all 82 cases), medication reduction (in 78 cases), and complications (in 82 cases).

Results

There was improvement in UPDRS scores across all measures following surgery. The total UPDRS score, off medication, improved from 68.78 (geometrical mean, 95% CI 61.76–76.60) preoperatively to 45.89 (geometrical mean, 95% CI 34.86–60.41) at 1 year postoperatively (p = 0.003, data available in 26 patients). Improvements were obtained in UPDRS Part II (Activities of Daily Living) off medication (p = 0.001) and also UPDRS Part III (Motor Examination) off medication (p < 0.001). Results for the on-medication and on-stimulation states also showed a statistically significant improvement for UPDRS Part III (p = 0.047). Good microelectrode recording of the STN was obtained under general anesthesia; the median first-track length was 4.0 mm, and the median number of tracks passed per patient was 3.0. The median reduction in levodopa medication was 58.1% (interquartile range 42.9%–73.3%). One patient had an intracerebral hemorrhage in the track of 1 electrode but did not require surgical evacuation. One patient had generalized convulsive seizures 24 hours postoperatively and was intubated for seizure control. Unified Parkinson's Disease Rating Scale scores were obtained in 26 patients at 1 year, 28 patients at 3 years, 17 at 5 years, and 7 at 7 years postoperatively. Up to 7 years postoperatively, there was sustained improvement in the total UPDRS score. The results in these patients showed minimal deterioration in the motor section of the UPDRS over time, up to 7 years following the operation. The authors found no evidence that the UPDRS Part II scores changed significantly over the period of 1–7 years after surgery (p = 0.671, comparison of mean scores at 1 and 7 years using generalized estimating equations).

Conclusions

Long-term outcomes confirm that it is both safe and effective to perform STN DBS under general anesthesia. As part of patient choice, this option should be offered to all DBS candidates with advanced Parkinson disease to enable more of these patients to undergo this beneficial surgery.
Pratiques de veille stratégique par les PME exportatrices
Authors: Amabile Serge , Laghzaoui Soulaimane , Boudrandi Stéphane
Published: October 2011

Résumé L’objectif de cet article est d’étudier les pratiques de veille stratégique des PME exportatrices et leur relation avec le niveau d’engagement à l’international. Les résultats montrent que la sensibilité à l’information des dirigeants, influencée par le niveau d’engagement international de leur entreprise, joue un rôle central dans l’organisation de leurs pratiques de veille stratégique. La recherche a porté sur les PME exportatrices québécoises et a utilisé la méthode PLS pour la vérification des hypothèses de recherche.
Processus de rencontre sur Internet : une étude empirique de la perception du risque
Authors: Chenavaz Régis , Paraschiv Corina
Published: October 2011

Résumé L’objectif de l’article est de comprendre le risque perçu des rencontres en ligne et les différences de perception du risque entre les rencontres en ligne et les rencontres traditionnelles en utilisant l’approche multidimensionnelle du risque perçu. Nous réalisons une étude empirique à partir de questionnaires postés sur des forums consacrés aux rencontres en ligne. Nous montrons tout d’abord que toutes les dimensions du risque perçu sont systématiquement plus fortes pour les rencontres en ligne que pour les rencontres traditionnelles. Ensuite, le classement de l’importance des différentes dimensions du risque est le même pour les rencontres en ligne et pour les rencontres traditionnelles. Enfin, nous mettons en évidence que le risque de performance et le risque de perte de temps sont les deux déterminants du risque perçu global des rencontres en ligne.
La « shazamisation » de l'offre : modalités, devenir et implications managériales
Authors: Lemoine Jean-François , Badot Olivier
Published: October 2011

Résumé Cet article attire l’attention sur un nouveau phénomène, la « shazamisation » de l’offre, qui - grâce à des applications dans les smartphones - permet aux consommateurs d’assouvir, au gré de leurs pérégrinations physiques et émotionnelles, leurs envies et leurs besoins en les transformant en achat immédiat, plus ou moins local. Pour rendre compte de ce phénomène, une analyse sociologique des modes de vie et des usages qui en favorisent l’émergence est tout d’abord menée. Puis sont présentés : un cas pratique de « shazamisation de l’offre », Collection Inspire et les conséquences sur le processus d’achat. Une conclusion signale des implications managériales de ce phénomène en matière de stratégies marketing, d’économie politique du canal et de commerce.
Segmentation fournisseurs et négociation : le cas du fournisseur « stratégique »
Authors: Lacoste Sylvie
Published: October 2011

Résumé Notre étude s’appuie sur la création récente d’un nouveau statut de fournisseur, dénommé « stratégique » au sein d’une typologie fournisseurs définis par les clients, grands groupes industriels. Par-delà cette nouvelle caractérisation des relations client-fournisseur, nous nous interrogeons sur l’impact de ce statut sur la négociation entre ce type de fournisseurs et leurs clients. Nous cherchons à définir les modifications d’enjeu et les conséquences.
L'apport de l'intelligence économique en négociation commerciale
Authors: Bobot Lionel
Published: October 2011

Résumé L’intelligence économique tend à trier et enrichir l’information et la documentation recueillies, dans le but de les traiter et de mettre en place la stratégie et le plan d’action en conséquence. L’intelligence économique et la négociation sont liées dans quatre principaux domaines : la recherche d’information, la cartographie des acteurs, le lobbying et les réseaux. Nous nous proposons dans cet article de présenter une recherche basée sur des entretiens qualitatifs approfondis auprès de commerciaux ayant pour projet de vérifier nos réflexions concernant l’apport de l’intelligence économique à la négociation commerciale. Mieux informé, influençant les acteurs clés de la négociation et utilisant au mieux ses réseaux sociaux, le commercial comme le dirigeant saura créer un avantage compétitif sur son marché et optimisera ses négociations.
Cost Associated with Being Overweight and with Obesity, High Alcohol Consumption, and Tobacco Use within the Military Health System's TRICARE Prime—Enrolled Population
Authors: Dall Timothy M. , Zhang Yiduo , Chen Yaozhu J. , Wagner Rachel C. Askarinam , Hogan Paul F. , Fagan Nancy K. , Olaiya Samuel T. , Tornberg David N.
Published: October 2011

Purpose.

To estimate medical and indirect costs to the Department of Defense (DoD) that are associated with tobacco use, being overweight or obese, and high alcohol consumption.

Design.

Retrospective, quantitative research.

Setting.

Healthcare provided in military treatment facilities and by providers participating in the military health system.

Subjects.

The 4.3 million beneficiaries under age 65 years who were enrolled in the military TRICARE Prime health plan option in 2006.

Measures.

The findings come from a cost-of-disease model developed by combining information from DoD and civilian health surveys and studies; DoD healthcare encounter data for 4.1 million beneficiaries; and epidemiology literature on the increased risk of comorbidities from unhealthy behaviors.

Results.

DoD spends an estimated $2.1 billion per year for medical care associated with tobacco use ($564 million), excess weight and obesity ($1.1 billion), and high alcohol consumption ($425 million). DoD incurs nonmedical costs related to tobacco use, excess weight and obesity, and high alcohol consumption in excess of $965 million per year.

Conclusion.

Unhealthy lifestyles are significant contributors to the cost of providing healthcare services to the nation's military personnel, military retirees, and their dependents. The continued rise in healthcare costs could impact other DoD programs and could potentially affect areas related to military capability and readiness. In 2006, DoD initiated Healthy Choices for Life initiatives to address the high cost of unhealthy lifestyles and behaviors, and the DoD continues to monitor lifestyle trends through the DoD Lifestyle Assessment Program.
Integrating Racially and Ethnically Diverse Communities Into Planning for Disasters: The California Experience
Authors: Andrulis Dennis P. , Siddiqui Nadia J. , Purtle Jonathan P.
Published: October 2011

Objectives:Racially/ethnically diverse communities suffer a disproportionate burden of adverse outcomes before, during and after a disaster. Using California as a locus of study, we sought to identify challenges and barriers to meeting the preparedness needs of these communities and highlight promising strategies, gaps in programs, and future priorities.

Methods:We conducted a literature review, environmental scan of organizational Web sites providing preparedness materials for diverse communities, and key informant interviews with public health and emergency management professionals.

Results:We identified individual-level barriers to preparing diverse communities such as socioeconomic status, trust, culture, and language, as well as institutional-level barriers faced by organizations such as inadequate support for culturally/linguistically appropriate initiatives. Current programs to address these barriers include language assistance services, community engagement strategies, cross-sector collaboration, and community assessments. Enhancing public-private partnerships, increasing flexibility in allocating funds and improving organizational capacity for diversity initiatives were all identified as additional areas of programmatic need.

Conclusions:Our study suggests at least four intervention priorities for California and across the United States: engaging diverse communities in all aspects of emergency planning, implementation, and evaluation; mitigating fear and stigma; building organizational cultural competence; and enhancing coordination of information and resources. In addition, this study provides a methodological model for other states seeking to assess their capacity to integrate diverse communities into preparedness planning and response.

(Disaster Med Public Health Preparedness. 2011;5:227–234)
The first case of myoclonic epilepsy in a child with a de novo 22q11.2 microduplication
Authors: Piccione Maria , Vecchio Davide , Cavani Simona , Malacarne Michela , Pierluigi Mauro , Corsello Giovanni
Published: October 2011

Chromosome 22, particularly the q11.2 sub‐band, has long been recognized as responsible for multiple congenital anomaly disorders. In particular, its susceptibility to subtle microdeletions or, more rarely, microduplications has been attributed to the presence of several low‐copy repeats spanning the region as mediators of nonallelic homologous recombination that result in 22q11.2 rearrangements. While recent data suggest that the frequency of 22q11.2 microduplications could be approximately half of all deletions, now only 50 unrelated cases have been reported thus far. However, it is reasonable to suppose that microduplications of 22q11.2 may be largely undetected as a result of a less‐distinct, unpredictable, and/or milder phenotype ranging from normal to mild learning difficulties with/without other multiple defects. We report on the first case of myoclonic epilepsy in a 10‐year‐old boy carrying a de novo 22q11.2 microduplication. Emphasizing that this rare association could be one of the many unrecognized aspects underlying this new emerging syndrome and once again its clinical heterogeneity, we suggest further investigation of the function of the RAB36 gene and propose that in the screening of individuals with developmental delay, minor behavioral problems mild dysmorphology and seizures, investigation of 22q11.2 microduplications should be considered. © 2011 Wiley Periodicals, Inc.
Newly recognized recessive syndrome characterized by dysmorphic features, hypogonadotropic hypogonadism, severe microcephaly, and sensorineural hearing loss maps to 3p21.3
Authors: Jenkinson Emma M. , Kingston Helen , Urquhart Jill , Khan Naz , Melville Athalie , Swinton Martin , Crow Yanick J. , Davis Julian R.E. , Trump Dorothy , Newman William G.
Published: October 2011

We present a newly recognized, likely autosomal recessive, pleiotropic disorder seen in four individuals (three siblings and their nephew) from a consanguineous family of Pakistani origin. The condition is characterized by hypogonadotropic hypogonadism, severe microcephaly, sensorineural deafness, moderate learning disability, and distinctive facial dysmorphic features. Autozygosity mapping using SNP array genotyping defined a single, large autozygous region of 13.1 Mb on chromosome 3p21 common to the affected individuals. The critical region contains 227 genes and initial sequence analysis of a functional candidate gene has not identified causative mutations. © 2011 Wiley Periodicals, Inc.
Bladder exstrophy: An epidemiologic study from the International Clearinghouse for Birth Defects Surveillance and Research, and an overview of the literature
Authors: Siffel Csaba , Correa Adolfo , Amar Emmanuelle , Bakker Marian K. , Bermejo‐Sánchez Eva , Bianca Sebastiano , Castilla Eduardo E. , Clementi Maurizio , Cocchi Guido , Csáky‐Szunyogh Melinda , Feldkamp Marcia L. , Landau Danielle , Leoncini Emanuele , Li Zhu , Lowry R. Brian , Marengo Lisa K. , Mastroiacovo Pierpaolo , Morgan Margery , Mutchinick Osvaldo M. , Pierini Anna , Rissmann Anke , Ritvanen Annukka , Scarano Gioacchino , Szabova Elena , Olney Richard S.
Published: October 2011

Bladder exstrophy (BE) is a complex congenital anomaly characterized by a defect in the closure of the lower abdominal wall and bladder. We aimed to provide an overview of the literature and conduct an epidemiologic study to describe the prevalence, and maternal and case characteristics of BE. We used data from 22 participating member programs of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). All cases were reviewed and classified as isolated, syndrome, and multiple congenital anomalies. We estimated the total prevalence of BE and calculated the frequency and odds ratios for various maternal and case characteristics. A total of 546 cases with BE were identified among 26,355,094 births. The total prevalence of BE was 2.07 per 100,000 births (95% CI: 1.90–2.25) and varied between 0.52 and 4.63 among surveillance programs participating in the study. BE was nearly twice as common among male as among female cases. The proportion of isolated cases was 71%. Prevalence appeared to increase with increasing categories of maternal age, particularly among isolated cases. The total prevalence of BE showed some variations by geographical region, which is most likely attributable to differences in registration of cases. The higher total prevalence among male cases and older mothers, especially among isolated cases, warrants further attention. © 2011 Wiley Periodicals, Inc.
New poly(1,3,4‐oxadiazole)s bearing pentadecyl side chains: Synthesis and characterization
Authors: More Arvind S. , Menon Shamal K. , Wadgaonkar Prakash P.
Published: October 2011

The 4‐[4′‐(Hydrazinocarbonyl)phenoxy]‐2‐pentadecylbenzohydrazide was polycondensed with aromatic diacid chlorides viz., terephthalic acid chloride (TPC), isophthalic acid chloride (IPC), and a mixture of TPC : IPC (50 : 50 mol %) to obtain polyhydrazides which on subsequent cyclodehydration reaction in the presence of phosphoryl chloride yielded new poly(1,3,4‐oxadiazole)s bearing flexibilizing ether linkages and pentadecyl side chains. Inherent viscosities of polyhydrazides and poly(1,3,4‐oxadiazole)s were in the range 0.53–0.66 dL g−1 and 0.49–0.53 dL g−1, respectively, indicating formation of medium to reasonably high molecular weight polymers. The number average molecular weights (Mn) and polydispersities (Mw/Mn) of poly(1,3,4‐oxadiazole)s were in the range 14,660–21,370 and 2.2–2.5, respectively. Polyhydrazides and poly(1,3,4‐oxadiazole)s were soluble in polar aprotic solvents such as N,N‐dimethylacetamide, 1‐methyl‐2‐pyrrolidinone, and N,N‐dimethylformamide. Furthermore, poly(1,3,4‐oxadiazole)s were also found to be soluble in solvents such as chloroform, dichloromethane, tetrahydrofuran, pyridine, and m‐cresol. Transparent, flexible, and tough films of polyhydrazides and poly(1,3,4‐oxadiazole)s could be cast from N,N‐dimethylacetamide and chloroform solutions, respectively. Both polyhydrazides and poly(1,3,4‐oxadiazole)s were amorphous in nature and formation of layered structure was observed due to packing of pentadecyl chains. A decrease in glass transition temperature was observed both in polyhydrazides (143–166°C) and poly(1,3,4‐oxadiazole)s (90–102°C) which could be ascribed to “internal plasticization” effect of pentadecyl chains. The T10 values, obtained from TG curves, for poly(1,3,4‐oxadiazole)s were in the range of 433–449°C indicating their good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124:1281–1289, 2012
Benefits of biogas upgrading to biomethane by high‐pressure reactive solvent scrubbing
Authors: Budzianowski Wojciech M.
Published: October 2011

Benefits of using high‐pressure reactive solvent scrubbing (HPRSS) for biogas upgrading to biomethane are discussed. Main technological advantage arises from the fact that biogas must pressurized for natural gas injection or compressed fuel applications and thus high‐pressure processes are particularly suitable for biogas upgrading. Ecological benefits associated with the HPRSS relate to: (i) the permanent lock‐up of carbon in its highest possible oxidation state (as CO2) in soil; (ii) soil fertilization by N, K, and P elements which are enriched in digestate; and (iii) soil fertilization by N or K elements contained in the CO2 saturated solvents from the biogas scrubbing units. The effect of pressure on the HPRSS process is studied in the falling film reactor geometry by means of 2D modeling and simulation. It is emphasized that elevated pressure has significant beneficial effects on CO2 separation rates because it increases CO2 removal efficiency and decreases dimensions of scrubbing reactors. Further, two promising reactive solvents are analyzed: NH3 and KOH – both demonstrated promising CO2 separation efficiencies. Moreover, both the reactive solvents allow production of valuable fertilizer additives, i.e. ammonium bicarbonate and potassium carbonate, respectively. The bench‐scale experiments of the HPRSS process realized in the counter‐current packed bed reactor reveal that NH3 vaporization from the scrubber can be minimized under the conditions of low temperature, pH, and flow rate of the gas and under the conditions of high‐pressure and flow rate of aqueous ammonia. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Techno‐economic analysis of a production‐scale torrefaction system for cellulosic biomass upgrading
Authors: Shah Ajay , Darr Matthew J. , Medic Dorde , Anex Robert P. , Khanal Sami , Maski Dev
Published: October 2011

Torrefaction of biomass early in the supply chain is one method of enhancing or preservin biomass quality during storage; reducing storage and transportation costs; attaining uniformity among different feedstock types; and meeting biorefineries' quality and quantity demands for feedstock in a cost effective and sustainable manner. The main objectives of this study were to analyze the mass and energy balance, to assess the techno‐economic feasibility of a production‐scale torrefaction system, and to quantify the sensitivity of energy and cost results to changes in initial feedstock moisture content, torrefaction process temperature, plant operating window, and initial capital investment. The output from this analysis provides clear guidance on the opportunities and costs associated with production‐scale torrefaction of biomass as a feedstock intermediate. Analysis of energy results indicated that the net external energy required for the torrefaction process increased and energy efficiency of the torrefaction system decreased with increasing moisture contents. However, both of these energy metrics exhibited a decreasing trend with increasing process temperatures. In addition to the energy results, unit torrefaction process cost exhibited a decreasing trend with decreasing initial moisture contents of feedstock and decreasing torrefaction process temperatures. For the typical moisture content of 30%wb, process temperature of 240°C, plant operating window of 6 mo.yr‐1 and initial capital investment of $7.5 million for the system with rated capacity of 25 Tton.hr‐1, unit torrefaction process cost was estimated to be 17.5 $‐Tton‐1. Additional system improvements through capital cost reduction and wider operating windows can yield a torrefaction product cost of ∼12 $‐Tton‐1. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Unusual modes of reproduction in social insects: Shedding light on the evolutionary paradox of sex
Authors: Wenseleers Tom , Van Oystaeyen Annette
Published: October 2011

The study of alternative genetic systems and mixed modes of reproduction, whereby sexual and asexual reproduction is combined within the same lifecycle, is of fundamental importance as they may shed light on classical evolutionary issues, such as the paradox of sex. Recently, several such cases were discovered in social insects. A closer examination of these systems has revealed many amazing facts, including the mixed use of asexual and sexual reproduction for the production of new queens and workers, males that can clone themselves and the routine use of incest without deleterious genetic consequences. In addition, in several species, remarkable cases of asexually reproducing socially parasitic worker lineages have been discovered. The study of these unusual systems promises to provide insight into many basic evolutionary questions, including the maintenance of sex, the expression of sexual conflict and kin conflict and the evolution of cheating in asexual lineages.
Modification of MCM‐41 with Anionic Surfactant: A Convenient Design for Efficient Removal of Cationic Dyes from Wastewater
Authors: Zanjanchi Mohammad Ali , Sajjadi Hassan , Arvand Majid , Mohammad‐Khah Ali , Ghalami‐Choobar Bahram
Published: October 2011

The potential of MCM‐41 for the removal of cationic dyes from water solution was evaluated using sodium dodecyl sulfate (SDS) for the surface modification of this mesoporous material. Admicelle structures formed on the surface of the calcined MCM‐41 are capable of removing organic pollutants and cationic species from water environment. The structural, textural, and surface chemical characteristics of the prepared SDS‐modified MCM‐41 (SDS‐MCM‐41) were studied. The adsorption capacity of SDS‐MCM‐41 was evaluated for methylene blue (MB) as a target cationic dye. Equilibrium adsorption isotherm data were manipulated employing nonlinear regression analysis. The Langmuir, Freundlich, and Sips isotherm models were examined. The adsorption data were well fitted to both Langmuir and Sips isotherm models. The maximum adsorption capacity of SDS‐MCM‐41 for MB, based on Langmuir and Sips models, were 290.8 and 297.3 mg g−1, respectively. Ethanol was found to be an effective solvent for partial regeneration of the adsorbent.
Cease‐fire at the leading edge: New perspectives on actin filament branching, debranching, and cross‐linking
Authors: Ydenberg Casey A. , Smith Benjamin A. , Breitsprecher Dennis , Gelles Jeff , Goode Bruce L.
Published: October 2011

Membrane protrusion at the leading edge of migrating cells is driven by the polymerization of actin. Recent studies using advanced imaging techniques raised a lively controversy about the morphology of these filaments; however, common ground between the two sides now appears to have been found. Here we discuss how the controversy has led to a deeper consideration of the architecture of actin networks underlying cell migration, and has helped define new challenges that lie ahead. © 2011 Wiley Periodicals, Inc.
Adaptation to a seasonally varying environment: a strong latitudinal cline in reproductive diapause combined with high gene flow in Drosophila montana
Authors: Tyukmaeva Venera I. , Salminen Tiina S. , Kankare Maaria , Knott K. Emily , Hoikkala Anneli
Published: October 2011

Adaptation to seasonal changes in the northern hemisphere includes an ability to predict the forthcoming cold season from gradual changes in environmental cues early enough to prepare for the harsh winter conditions. The magnitude and speed of changes in these cues vary between the latitudes, which induces strong selection pressures for local adaptation.

We studied adaptation to seasonal changes in Drosophila montana, a northern maltfly, by defining the photoperiodic conditions leading to adult reproductive diapause along a latitudinal cline in Finland and by measuring genetic differentiation and the amount of gene flow between the sampling sites with microsatellites. Our data revealed a clear correlation between the latitude and the critical day length (CDL), in which half of the females of different cline populations enter photoperiodic reproductive diapause. There was no sign of limited gene flow between the cline populations, even though these populations showed isolation by distance. Our results show that local adaptation may occur even in the presence of high gene flow, when selection for locally adaptive life‐history traits is strong. A wide range of variation in the CDLs of the fly strains within and between the cline populations may be partly due to gene flow and partly due to the opposing selection pressures for fly reproduction and overwinter survival. This variation in the timing of diapause will enhance populations’ survival over the years that differ in the severity of the winter and in the length of the warm period and may also help them respond to long‐term changes in environmental conditions.
Methyl 2‐Furoate: An Alternative Reagent to Furan for Palladium‐Catalysed Direct Arylation
Authors: Fu Hai Yan , Doucet Henri
Published: October 2011

The palladium‐catalysed direct arylation of methyl 2‐furoate with aryl bromides was studied. The use of KOAc as the base, dimethylacetamide (DMAc) as the solvent and Pd(OAc)2 as the catalyst was found to give 5‐arylfurans regioselectively and without decarboxylation. These methyl 5‐aryl‐2‐furoates gave 2,5‐diarylfurans by decarboxylative coupling by using Pd(OAc)2 as the catalyst. Methyl 2‐furoate thus represents a convenient alternative substrate to furan for the synthesis of mono‐ or poly‐arylated furans.
Urea Amperometric Biosensors Based on Nanostructured Polypyrrole
Authors: Massafera Mariana P. , de Torresi Susana I. Córdoba
Published: October 2011

In this work, we report the development of urea biosensors using macroporous polypyrrole as electrochemical transducer. Nanostructured polypyrrole was synthesized using monodispersed polystyrene spheres (460 nm) as template. Nanostructured urea biosensors were assembled after immobilization of urease (an enzyme that hydrolyses urea to ammonia) on macroporous polypyrrole, which was carried out using two different procedures: covalent attachment or layer‐by‐layer (lbl) deposition. Results show that lbl assembly of urease on macroporous polypyrrole gives rise to biosensors with improved detection kinetics (as demonstrated by higher Imax values) and tunable sensitivities. Comparison with bulk urea biosensors previously described in the literature demonstrates that the use of nanostructured polypyrrole as sensing platform enhances biosensor′s analytical performances, mainly due to the availability of more active sites for enzyme immobilization.
Interspecies comparisons on the uptake and toxicity of silver and cerium dioxide nanoparticles
Authors: Gaiser Birgit K. , Fernandes Teresa F. , Jepson Mark A. , Lead Jamie R. , Tyler Charles R. , Baalousha Mohammed , Biswas Anamika , Britton Graham J. , Cole Paula A. , Johnston Blair D. , Ju-Nam Yon , Rosenkranz Philipp , Scown Tessa M. , Stone Vicki
Published: October 2011

An increasing number and quantity of manufactured nanoparticles are entering the environment as the diversity of their applications increases, and this will lead to the exposure of both humans and wildlife. However, little is known regarding their potential health effects. We compared the potential biological effects of silver (Ag; nominally 35 and 600–1,600 nm) and cerium dioxide (CeO2; nominally <25 nm and 1–5 µm) particles in a range of cell (human hepatocyte and intestinal and fish hepatocyte) and animal (Daphnia magna, Cyprinus carpio) models to assess possible commonalities in toxicity across taxa. A variety of analytical techniques were employed to characterize the particles and investigate their biological uptake. Silver particles were more toxic than CeO2 in all test systems, and an equivalent mass dose of Ag nanoparticles was more toxic than larger micro-sized material. Cellular uptake of all materials tested was shown in C3A hepatocytes and Caco-2 intestinal cells, and for Ag, into the intestine, liver, gallbladder, and gills of carp exposed via the water. The commonalities in toxicity of these particle types across diverse biological systems suggest that cross-species extrapolations may be possible for metal nanoparticle test development in the future. Our findings also suggest transport of particles through the gastrointestinal barrier, which is likely to be an important uptake route when assessing particle risk. Environ. Toxicol. Chem. 2012;31:144–154. © 2011 SETAC
Starburst low‐molecular weight polyethylenimine for efficient gene delivery
Authors: Zhao Yanjun , Yang Rulei , Liu Dong , Sun Mingjing , Zhou Lijun , Wang Zheng , Wan Ying
Published: October 2011

Low‐molecular weight polyethylenimine (LMW PEI) shows the advantage of low‐cytotoxicity, but has been inefficient in gene delivery as a consequence of the low‐charge density. A number of previous studies employed the approach of crosslinking to solve this problem. In this study, a starburst LMW PEI gene vector has been developed. It has a polyamidoamine (PAMAM) core conjugated with a shell composed of LWM PEI and polyethylene glycol (PEG), that is PAMAM‐PEI‐PEG. Plasmid DNA (pEGFP‐N1) and human cervix epithelial carcinoma (HeLa) cells were used in the study. The results showed that the starburst LMW PEI could effectively condense DNA at N/P above 5. The polyplexes had a size of about 500 nm and a nearly neutral surface because of the PEG shielding effect. This novel gene vector is able to maintain the low‐cytotoxicity of LMW PEI, whereas its transfection efficiency was significantly improved. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Empirical formulation and parameterization of cation–π interactions for protein modeling
Authors: Du Qi‐Shi , Long Si‐Yu , Meng Jian‐Zong , Huang Ri‐Bo
Published: October 2011

Cation–π interaction is comparable and as important as other main molecular interaction types, such as hydrogen bond, electrostatic interaction, van der Waals interaction, and hydrophobic interaction. Cation–π interactions frequently occur in protein structures, because six (Phe, Tyr, Trp, Arg, Lys, and His) of 20 natural amino acids and all metallic cations could be involved in cation–π interaction. Cation–π interactions arise from complex physicochemical nature and possess unique interaction behaviors, which cannot be modeled and evaluated by existing empirical equations and force field parameters that are widely used in the molecular dynamics. In this study, the authors present an empirical approach for cation–π interaction energy calculations in protein interactions. The accurate cation–π interaction energies of aromatic amino acids (Phe, Tyr, and Try) with protonated amino acids (Arg and Lys) and metallic cations (Li+, Na+, K+, and Ca2+) are calculated using B3LYP/6‐311+G(d,p) method as the benchmark for the empirical formulization and parameterization. Then, the empirical equations are built and the parameters are optimized based on the benchmark calculations. The cation–π interactions are distance and orientation dependent. Correspondingly, the empirical equations of cation–π interactions are functions of two variables, the distance r and the orientation angle θ. Two types of empirical equations of cation–π interactions are proposed. One is a modified distance and orientation dependent Lennard–Jones equation. The second is a polynomial function of two variables r and θ. The amino acid‐based empirical equations and parameters provide simple and useful tools for evaluations of cation–π interaction energies in protein interactions. © 2011 Wiley Periodicals, Inc. J Comput Chem , 2011
Micro‐structural tissue analysis for automatic histopathological image annotation
Authors: Díaz Gloria , Romero Eduardo
Published: October 2011

This article presents a new approach for extracting high level semantic concepts from digital histopathological images. This strategy provides not only annotation of several biological concepts, but also a coarse location of these concepts. The proposed approach is composed of five main steps: (1) a stain decomposition stage, which separates the contribution of hematoxylin and eosin dyes, (2) a color standardization that corrects color image differences, (3) a part‐based representation, which describes the image in terms of the conditional probability of relevant local patches, selected by their stain contributions, (4) a discriminative classification model, which bridges out the found patterns and the biological concepts, (5) a block‐based annotation strategy that identifies the multiple biological concepts within an image. A set of 655 skin images, containing 10 biological concepts of skin tissues were used for assessing the proposed approach, obtaining a sensitivity of 84% and a specificity of 67% when annotating images with multiple concepts. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Automatic segmentation on multiple starch granules from microscopic images
Authors: Guo Shengwen
Published: October 2011

Starch is the most important carbohydrate in the human diet and contained in many staple foods such as rice, wheat, corn, potatoes and cassava, etc. Currently, microscopic imaging technology is one of the most effective ways to investigate and analyze the structure of starches. Segmentation of starch granules is a necessary step for starch granule structure analysis such as starch granules detection, shape recognition, and size computation. This article investigates a new method based on GVF (gradient vector flow) snake deformable model for starch granules segmentation. The proposed method focuses on full automatic segmentation on granules, especially on separation of adjacent and contacted starch granules, which occur widely in microscopic images. A novel energy function based on position and intensity is introduced into the directional gradient computation, thus the directional gradient is used to obtain the directional GVF snake, which drives the deforming contours to the real contours of multiple granules. To demonstrate the good ability of the proposed method, we segment 30 starch granule images and compare it with the level set method, experimental results show that the new method can separate multiple starch granules successfully; especially it works much better on overlapping objects segmentation than the level set method. Microsc. Res. Tech. 2011. © 2011 Wiley‐Liss, Inc.
Contribution of body mass index to postoperative outcome in minority patients
Authors: Nafiu Olubukola O. , Ramachandran Satya Krishna , Wagner Deborah S. , Campbell Darrell A. , Stanley James C.
Published: October 2011

OBJECTIVE:

The purpose of this investigation was to examine the association of body mass index (BMI) category with short‐term outcomes in minority surgical patients—a relationship that previously has not been well characterized.

METHODS:

Data from the National Surgical Quality Improvement Program were used to calculate the BMI of minority patients undergoing surgery from 2005 to 2008. Patients were stratified into 5 BMI classes. Stepwise logistic regression was used to calculate odds ratios for mortality after controlling for known clinically relevant covariates.

MAIN OUTCOME MEASURES:

Morbidity and mortality at 30 days, across all 5 BMI classes.

RESULTS:

Among 119,619 minority patients studied, 50% were African American, 36% Hispanic, 10% Asian and Pacific Islanders, and 4% American Indian and Alaskan natives. Seventy percent were overweight or obese. Women were more likely to be obese or severely obese. The overall mortality rate was 1.5%, and this varied significantly by BMI class. Distribution of 30‐day mortality demonstrated a progressive decrease, with the highest risk of death in the underweight class, and the lowest risk of death in the severely obese class. This relationship was maintained, even in patients with at least 1 major postoperative complication.

CONCLUSION:

The prevalence of being overweight or obese was high in this nationally representative cohort of minority surgical patients. Although BMI class is a significant predictor of 30‐day mortality, the effect appeared paradoxical. The poorest outcomes were in the underweight and normal BMI patients. Severely obese patients had the lowest risk of mortality, even after experiencing a major postoperative complication. Journal of Hospital Medicine 2012; © 2011 Society of Hospital Medicine.
High‐resolution ultrashort echo time (UTE) imaging on human knee with AWSOS sequence at 3.0 T
Authors: Qian Yongxian , Williams Ashley A. , Chu Constance R. , Boada Fernando E.
Published: October 2011

Purpose:

To demonstrate the technical feasibility of high‐resolution (0.28–0.14 mm) ultrashort echo time (UTE) imaging on human knee at 3T with the acquisition‐weighted stack of spirals (AWSOS) sequence.

Materials and Methods:

Nine human subjects were scanned on a 3T MRI scanner with an 8‐channel knee coil using the AWSOS sequence and isocenter positioning plus manual shimming.

Results:

High‐resolution UTE images were obtained on the subject knees at TE = 0.6 msec with total acquisition time of 5.12 minutes for 60 slices at an in‐plane resolution of 0.28 mm and 10.24 minutes for 40 slices at an in‐plane resolution of 0.14 mm. Isocenter positioning, manual shimming, and the 8‐channel array coil helped minimize image distortion and achieve high signal‐to‐noise ratio (SNR).

Conclusion:

It is technically feasible on a clinical 3T MRI scanner to perform UTE imaging on human knee at very high spatial resolutions (0.28–0.14 mm) within reasonable scan time (5–10 min) using the AWSOS sequence. J. Magn. Reson. Imaging 2012;35:204‐210. © 2011 Wiley Periodicals, Inc.
Protonation sites and dissociation mechanisms of t‐butylcarbamates in tandem mass spectrometric assays for newborn screening
Authors: Spáčil Zdeněk , Hui Renjie , Gelb Michael H. , Tureček František
Published: October 2011

Structures of tert‐butylcarbamate ions in the gas‐phase and methanol solution were studied for simple secondary and tertiary carbamates as well as for carbamate‐containing products and internal standards for lysosomal enzyme assays used in newborn screening of a α‐galactosidase A deficiency (Fabry disease), mucopolysaccharidosis I (Hurler disease), and mucopolysaccharidosis II (Hunter disease). The protonation of simple t‐butylcarbamates can occur at the carbonyl group, which is the preferred site in the gas phase. Protonation in methanol solution is more favorable if occurring at the carbamate nitrogen atom. The protonation of more complex t‐butylcarbamates occurs at amide and carbamate carbonyl groups, and the ions are stabilized by intramolecular hydrogen bonding, which is affected by solvation. Tertiary carbamates containing aminophenol amide groups were calculated to have substantially greater gas‐phase basicities than secondary carbamates containing coumarin amide groups. The main diagnostically important ion dissociation by elimination of 2‐methylpropene (isobutylene, i‐C4H8) and carbon dioxide is shown by experiment and theory to proceed in two steps. Energy‐resolved collision‐induced dissociation of the Hurler's disease enzymatic product ion, which is a coumarin‐diamine linker‐t‐butylcarbamate conjugate (3a+), indicated separate energy thresholds for the loss of i‐C4H8 and CO2. Computational investigation of the potential energy surface along two presumed reaction pathways indicated kinetic preference for the migration of a t‐butyl hydrogen atom to the carbamate carbonyl resulting in the isobutylene loss. The consequent loss of CO2 required further proton migrations that had to overcome energy barriers. Copyright © 2011 John Wiley & Sons, Ltd.
Anterior cervical interbody constructs: effect of a repetitive compressive force on the endplate
Authors: Ordway Nathaniel R. , Rim Byeong Cheol , Tan Rong , Hickman Rebecca , Fayyazi Amir H.
Published: October 2011

Graft subsidence following anterior cervical reconstruction can result in the loss of sagittal balance and recurring foraminal stenosis. This study examined the implant–endplate interface using a cyclic fatigue loading protocol in an attempt to model the subsidence seen in vivo. The superior endplate from 30 cervical vertebrae (C3 to T1) were harvested and biomechanically tested in axial compression with one of three implants: Fibular allograft; titanium mesh cage packed with cancellous chips; and trabecular metal. Each construct was cyclically loaded from 50 to 250 N for 10,000 cycles. Nondestructive cyclic loading of the cervical endplate–implant construct resulted in a stiffer construct independent of the type of the interbody implant tested. The trabecular metal construct demonstrated significantly more axial stability and significantly less subsidence in comparison to the titanium mesh construct. Although the allograft construct resulted in more subsidence than the trabecular metal construct, the difference was not significant and no difference was found when comparing axial stability. For all constructs, the majority of the subsidence during the cyclic testing occurred during the first 500 cycles and was followed by a more gradual settling in the remaining 9,500 cycles. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:587–592, 2012
Possibilities of enhancing the colour of egg yolk
Authors: Dvořák Petr , Suchý Pavel , Straková Eva , Kopřiva Vladimír
Published: October 2011

BACKGROUND: This study attempts to compare two possibilities of enhancing the colour of egg yolk. One of them is based on the ecological rearing of laying hens on natural green grass whereas the other uses a feeding dose supplemented with natural pigments in laying hens reared in individual cages. Is it possible to distinguish these two technologies using yolk colour determination in the CIELAB system?

RESULTS: Yolk colour parameters such as L*, a*, and b* in the group of grazed hens are significantly different (α = 0.001) from those observed in hens reared in cages. The yolk colour shows a darker, redder and more yellow colour. The greatest difference was seen in the red colour parameter, a*, that increased more than twice. Visually, this means a shift towards a more orange colour. Compared to grazing in the meadow (ΔE* = 13.257), the addition of artificial pigments in the feed resulted in a more significant increase in the parameter ΔE* (CIE total colour difference), with the greatest value of ΔE* being observed with the use of both pigments (ΔE* = 24.265).

CONCLUSION: Grazing increases the parameter a* whereas the values of the parameter C*ab remain relatively low. The parameter ΔE* is significantly lower in the case of grazing as compared to the supplementation of the feed with pigments. However, colourity parameters cannot be used as a specific standard to identify a particular grazing technology as their values vary during the laying period. Copyright © 2011 Society of Chemical Industry