bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane Fusion
Authors: Blumenthal R. , Dimitrov D. S. 
Published: November 2010

AbstractThe sections in this article are:Observation of Fusion Requires Physical Techniques for Monitoring Mixing of Membranes and the Compartments they EncloseMorphological Changes Following Fusion Are Observed by Light Microscopy but Membrane Fusion May Occur without such ChangesFluorescence Microscopy and Spectrofluorometry Allow Quantitation of Membrane Fusion Events in Living CellsElectron Microscopy Provides Direct Observation of Structural Rearrangements Due to FusionPatch‐Clamp Techniques Allow the Monitoring of Very Fast Openings of Fusion PoresWhat Do We Learn from “Nonbiological” Fusion Processes?Ca2+Induces Aggregation Destabilization, and Fusion of Liposomes Containing Phospholipids with Negatively Charged Head‐groupsFusion of Lipid Membranes by Amphipathic and Nonpolar Molecules Correlates with Their Lytic and Aggregational ActivityDehydration, Aggregation, and Destabilization of Membranes by Polyethelene Glycol Are Essential for Fusion of Lipid MembranesDestabilization by High‐Voltage Electric Pulses Leads to Fusion of Adjoining MembranesMolecular Rearrangements in the Lipid Bilayers during the Very Act of Fusion May Involve Intermediate StructuresSpecialized Proteins Mediate Fusion in Life ProcessesViral Envelope Proteins Contain Hydrophobic “Fusion Peptide” SequencesTo Enter a Cell a Virus Must Find the Receptor That Invites It InSome Viruses Require More Than One Type of Envelope Protein for EntryInfluenza Hemagglutinin Was the Only Fusion Protein with Known Three‐Dimensional StructureThe Process ofHA‐mediated Membrane Fusion Can Be Dissected into a Number of Elementary StepsHuman Immunodeficiency Virus Type 1 (HIV‐1), the Primary Etiological Agent of the Acquired Immunodeficiency Syndrome (AIDS), Enters Cells by Membrane Fusion at Neutral pHThe ReceptorCD4 Plays Both a Passive and an Active Role in Allowing Entry of the Virus into the CellStable Envelope Glycoprotein‐Receptor Complex Formation Is Rate‐limiting in the Overall Fusion ProcessMultiple Copies of theHIV‐1 Envelope Glycoprotein May Be Required for Fusion Pore FormationSperm Membrane Proteins Involved in Sperm‐Egg Fusion May Resemble Viral Fusion ProteinsToward A Resolution of Fusion Proteins in ExocytosisMultiple Proteins May Be Required for Intracellular FusionToward A Physicochemical Analysis of Fusion KineticsDelays in Fusion Are Proportional to the Fusion Barriers and Decrease with an Increase in the Strength of the FusogenRates of Fusion Can Provide Information for the Time Course of Membrane Merging and Fusion Pore ExpansionFusion Yields and Delays Are Related but May Reflect Different Properties of the Fusing MembranesDoes Understanding Membrane Fusion Need New Breakthroughs in Methodology?Note Added in Proof
Epithelial Cell Polarity: Challenges and Methodologies
Authors: Caplan Michael J. , Rodriguez‐Boulan Enrique 
Published: November 2010

AbstractThe sections in this article are:QuestionsTools and Techniques with Which to Study Epithelial PolarityEpithelial Monolayers Grown on Permeable SubstrataMorphological TechniquesBiochemical TechniquesProtein Trafficking Pathways in Epithelial CellsBiogenetic PathwaysTranscytosisRecycling PathwaysTissue‐Specific Variation of Protein Polarity and Targeting Pathways in Epithelial CellsSorting Signals and MechanismsEstablishment of Epithelial PolarityThe Role of E‐CadherinFuture Prospects: In Vitro Systems, Genetic Models, and the Search for Sorting Machinery
Activation of Sperm and Egg During Fertilization
Authors: Epel David 
Published: November 2010

AbstractThe sections in this article are:Chemotaxis (or, the Dating Game)Historical BackgroundMotility and Chemotactic Substances in Sea Urchin GametesDoes Chemotaxis Exist in the Real World?The Acrosome ReactionDescription of the PhenomenonSignal Transduction MoleculesSperm‐Egg BindingPassage of the Sperm Through the Egg CoatSperm‐Egg Receptors and SpeciationA Description of Egg ActivationWhat Happens When Sperm Meets Egg?The Role of Calcium in Egg ActivationHistorical BackgroundThe Natural History of Calcium Changes at FertilizationMechanisms of the Calcium IncreaseHow Does the Sperm Trigger the Calcium Increase?What is Calcium Doing to Activate the Egg?The Timetable of Fertilization Responses in the Sea Urchin EggIntracellular pH ChangesEntry into the Cell CycleSynthesis of Cyclin as a Prerequisite for MitosisActivation of Protein Kinase Activity As a Prerequisite for MitosisStructural Changes as an Important Concomitant of FertilizationMicrofilamentsMicrotubulesEndoplasmic ReticulumIntroduction of the Centrosome as a Critical EventOoplasmic SegregationEpilogue—Is Fertilization a Unique Event in the Life History of the Organism?
Partitioned iterative solution methods for fluid–structure interaction
Authors: van Brummelen E. H. 
Published: November 2010

AbstractThe basic subiteration method for fluid–structure interaction (FSI) problems is based on a partitioning of the fluid–structure system into a fluidic part and a structural part. The effect of the fluid on the structure can be represented by an added mass to the structural operator. This added mass can be identified as an upper bound on the norm or spectral radius of the Poincar'e–Steklov operator of the fluid. The convergence behavior of the subiteration method depends sensitively on the ratio of the added mass to the actual structural mass. For FSI problems with large added‐mass effects, the subiteration method is either unstable or its convergence behavior is prohibitively inefficient. In recent years, several more advanced partitioned iterative solution methods have been proposed for this class of problems, which use subiteration as a component. The rudimentary characterization of the Poincaré–Steklov operator provided by the added mass is, however, inadequate to analyze these methods. Moreover, this characterization is inappropriate for compressible flows. In this paper, we investigate the fine properties of the Poincaré–Steklov operators and of the corresponding subiteration operators for incompressible‐ and compressible flow models and for two distinct structural operators. Based on the characteristic properties of the subiteration operators, we subsequently examine the convergence behavior of several partitioned iterative solution methods for FSI, viz. subiteration, subiteration in conjunction with underrelaxation, the modified‐mass method, Aitken's method, and interface‐GMRES and interface‐Newton–Krylov methods. Copyright © 2010 John Wiley & Sons, Ltd.
Block response‐adaptive randomization in clinical trials with binary endpoints
Authors: Magirr Dominic 
Published: November 2010

AbstractIn a clinical trial, response‐adaptive randomization (RAR) uses accumulating data to weigh the randomization of remaining patients in favour of the better performing treatment. The aim is to reduce the number of failures within the trial. However, many well‐known RAR designs, in particular, the randomized play‐the‐winner‐rule (RPWR), have a highly myopic structure which has sometimes led to unfortunate randomization sequences when used in practice.This paper introduces random permuted blocks into two RAR designs, the RPWR and sequential maximum likelihood estimation, for trials with a binary endpoint. Allocation ratios within each block are restricted to be one of 1:1, 2:1 or 3:1, preventing unfortunate randomization sequences. Exact calculations are performed to determine error rates and expected number of failures across a range of trial scenarios. The results presented show that when compared with equal allocation, block RAR designs give similar reductions in the expected number of failures to their unmodified counterparts. The reductions are typically modest under the alternative hypothesis but become more impressive if the treatment effect exceeds the clinically relevant difference. Copyright © 2010 John Wiley & Sons, Ltd.
Prospective Identification and Isolation of Enteric Nervous System Progenitors Using Sox2
Authors: Heanue Tiffany A. , Pachnis Vassilis 
Published: November 2010

Abstract
The capacity to identify and isolate lineage-specific progenitor cells from developing and mature tissues would enable the development of cell replacement therapies for disease treatment. The enteric nervous system (ENS) regulates important gut functions, including controlling peristaltic muscular contractions, and consists of interconnected ganglia containing neurons and glial cells. Hirschsprung's disease (HSCR), one of the most common and best understood diseases affecting the ENS, is characterized by absence of enteric ganglia from the distal gut due to defects in gut colonization by neural crest progenitor cells and is an excellent candidate for future cell replacement therapies. Our previous microarray experiments identified the neural progenitor and stem cell marker SRY-related homoebox transcription factor 2 (Sox2) as expressed in the embryonic ENS. We now show that Sox2 is expressed in the ENS from embryonic to adult stages and constitutes a novel marker of ENS progenitor cells and their glial cell derivatives. We also show that Sox2 expression overlaps significantly with SOX10, a well-established marker of ENS progenitors and enteric glial cells. We have developed a strategy to select cells expressing Sox2, by using G418 selection on cultured gut cells derived from Sox2βgeo/+ mouse embryos, thus allowing substantial enrichment and expansion of neomycin-resistant Sox2-expressing cells. Sox2βgeo cell cultures are enriched for ENS progenitors. Following transplantation into embryonic mouse gut, Sox2βgeo cells migrate, differentiate, and colocalize with the endogenous ENS plexus. Our studies will facilitate development of cell replacement strategies in animal models, critical to develop human cell replacement therapies for HSCR.
Compositional refinement in agent-based security protocols
Authors: McIver A. K. , Morgan C. C. 
Published: November 2010

Abstract

A truly secure protocol is one which
never
violates its security requirements, no matter how bizarre the circumstances, provided those circumstances are within its terms of reference. Such cast-iron guarantees, as far as they are possible, require formal, rigorous techniques: proof or model-checking. Informally, they are difficult or impossible to achieve. Our rigorous technique is
refinement
, until recently not much applied to security. We argue its benefits by using refinement-based program algebra to develop several security case studies. That is one of our contributions here. The soundness of the technique follows from its compositional semantics, one which we defined (elsewhere) to support a specialisation of standard refinement by enriching standard semantics with information that tracks correlations between hidden state and visible behaviour. A further contribution is to extend the basic theory of secure refinement (Morgan in Mathematics of program construction, Springer, Berlin, vol. 4014, pp. 359–378,
2006
) with special features required by our case studies, namely agent-based systems with complementary security requirements, and looping programs.
The sociolinguistics of a short-lived innovation: Tracing the development of quotative all across spoken and internet newsgroup data
Authors: Buchstaller Isabelle , Rickford John R. , Traugott Elizabeth Closs , Wasow Thomas , Zwicky Arnold 
Published: November 2010

AbstractThis paper examines a short-lived innovation, quotative all, in real and apparent time. We used a two-pronged method to trace the trajectory of all over the past two decades: (i) Quantitative analyses of the quotative system of young Californians from different decades; this reveals a startling crossover pattern: in 1990/1994, all predominates, but by 2005, it has given way to like. (ii) Searches of Internet newsgroups; these confirm that after rising briskly in the 1990s, all is declining. Tracing the changing usage of quotative options provides year-to-year evidence that all has recently given way to like. Our paper has two aims: We provide insights from ongoing language change regarding short-term innovations in the history of English. We also discuss our collaboration with Google Inc. and argue for the value of newsgroups to research projects investigating linguistic variation and change in real time, especially where recorded conversational tokens are relatively sparse.
Un reencuentro con Mundo Perido, Tikal, Guatemala
Authors: Laporte Juan Pedro , Fialko Vilma 
Published: November 2010

ResumenComo parte integral del área central de Tikal se encuentra un amplio conjunto arquitectónico conocido como Mundo Perdido. Entre 1979 y 1984 se llevaron a cabo trabajos de exploración arqueológica en las estructuras que le conforman, las cuales son un claro indicio de que se trató del Complejo de Conmemoración Astronómica o de Ritual Público de Tikal, en donde se condujeron actividades de conducción ritual, calendárica y, en algunos momentos, también politica. Su largo proceso evolutivo dio inicio desde el preclásico medio y continuó en forma ininterumpida hasta el clásico terminal. Este largo espectro cronológico, aunado a la importancia que este conjunto tuvo en la estructura política de Tikal, permite observar una parte de la historia del sitio a través de 1500 años. Se obtuvo una serie de elementos que permiten referir procesos históricos, preferencias cerámicas en la tradición funeraria, estilos arquitectónicos particulars y otros desarrollos, con lo cual se trata de ampliar el criterio con el cuai se ha planteado por lo general el panorama de Tikal en las tierras bajas centrales.
The Investigation of Obsidian Craft Production at Xochicalco, Morelos
Authors: Hirth Kenneth G. 
Published: November 2010

AbstractSurface reconnaissance at the site of Xochicalco, Morelos, identified 12 areas believed to be production locales where obsidian tools were manufactured during the Epiclassic period (A.D. 700-900). Production locales were identified from concentrations of chipped stone debitage located in both residential and nonresidential contexts at Xochicalco. Differences in the size and location of these production locales suggested obsidian craft activity was carried out in three different production contexts similar to those reported at the large urban center of Teotihuacan: small domestic workshops, large nonresidential workshops, and civic-ceremonial precinct workshops. Stratigraphic excavations were initiated to test whether the inferences about the context of production based on surface concentrations of obsidian debitage would be confirmed by subsurface testing. The results show that in most cases surface concentrations of obsidian debitage accurately reflect the presence of in situ craft activity.
Gallbladder motility before and after Billroth II gastric resection
Authors: CHILOIRO M. , PEZZOLLA F. , RIEZZO G. , MASELLI M. A. , LORUSSO D. 
Published: November 2010

AbstractThe aim of this study was to determine the effect of Billroth II gastric resection (BII) without vagotomy on gallbladder contraction in response to meal and CCK‐OP infusion. Fourteen duodenal ulcer patients were studied before surgery and six months postoperatively. Gallbladder volume was measured by real‐time ultrasonography. After surgery, there was a significant increase in fasting gallbladder volume (P < 0.05). Postprandial gallbladder emptying was not significantly affected by gastrectomy apart from a trend towards a shorter t1/2 and a larger ejection volume. In addition, postoperative gallbladder relaxation was more pronounced at time 120 min. In response to cholecystokinin‐octapeptide (CCK‐OP) infusion, there was a significant decrease of t1/2 after BII and a prolonged contraction with a significantly reduced gallbladder volume. Our data show that the gallbladder response both to meal and CCK‐OP infusion is modified after BII and a larger postoperative gallbladder volume may play a role in the pathogenesis of gallstone disease after gastric surgery.
Percutaneous vs surgical cryoablation of the small renal mass: is efficacy compromised?
Authors: Long Christopher J. , Kutikov Alexander , Canter Daniel J. , Egleston Brian L. , Chen David Y.T. , Viterbo Rosalia , Boorjian Stephen A. , Uzzo Robert G. 
Published: November 2010

Study Type – Therapy (systematic review)  Level of Evidence 1b What’s known on the subject? and What does the study add? Cryoablation of the small renal mass is one amongst many minimally invasive approaches to treatment. Cryoablation can be performed both surgically and percutaneously; direct comparison of the two approaches has proven the percutaneous approach to be cheaper, less morbid, result in shorter procedure times, and shorter hospital stays, all with equal efficacy. Our study examines the decision as well as reporting process for the selection of treatment approach to determine if patients are being unnecessarily exposed to more invasive therapeutic options.OBJECTIVE

To review and analyse the cumulative literature to compare surgical and percutaneous cryoablation of small renal masses (SRMs).

METHODS

A MEDLINE search was performed (1966 to February 2010) of the published literature in which cryoablation was used as therapy for localized renal masses.
Residual disease was defined as persistent enhancement on the first post‐ablation imaging study, while recurrent disease was defined as enhancement after an initially negative postoperative imaging study, consistent with the consensus definition by the Working Group on Image‐Guided Tumor Ablation.
Data were collated and analysed using the two‐sample Mann–Whitney test and random‐effects Poisson regression, where appropriate.

RESULTS

In all, 42 studies, representing 1447 lesions treated by surgical (n= 28) or percutaneous (n= 14) cryoablation were pooled and analysed.
No significant differences were detected between approaches regarding patient age (median 67 vs 66 years, P= 0.55), tumour size (median 2.6 vs 2.7 cm, P= 0.24),or duration of follow‐up (median 14.9 vs 13.3 months, P= 0.40).
Differences in rates of unknown pathology also failed to reach statistical significance (14 vs 21%, P= 0.76). The difference in the rate of residual tumour was not statistically different (0.033 vs 0.046, P= 0.25), nor was the rate of recurrent tumour (0.008 vs 0.009, P= 0.44).
The reported rate of metastases was negligible in both groups, precluding statistical analysis.

CONCLUSIONS

Cryoablation has shown acceptable short‐term oncological results as a viable strategy for SRMs.
Analysis of the cumulative literature to date shows that surgical and percutaneous cryoablation have similar oncological outcomes.
Density‐dependent and density‐independent responses of three species of Telenomus parasitoids of hemlock looper eggs
Authors: Carleton Drew , Quiring Dan , Heard Steve , Hébert Christian , Delisle Johanne , Berthiaume Richard , Bauce Eric , Royer Lucie 
Published: November 2010

AbstractWe examined patterns of host exploitation by natural populations of three Telenomus species (Hymenoptera: Scelionidae) parasitizing hemlock looper, Lambdina fiscellaria Guenée (Lepidoptera: Geometridae), eggs in sentinel traps in eastern Quebec and western Newfoundland (Canada). The percentage of eggs parasitized by Telenomus flavotibiae Pelletier and Telenomus coloradensis Crawford in autumn, and by Telenomus droozi Muesebeck in spring either were not or only weakly related to host egg density. In contrast, the percentage of eggs parasitized by T. coloradensis in the spring was positively related to host egg density. Telenomus flavotibiae and T. droozi parasitized eggs in fewer traps than T. coloradensis, suggesting that they were less abundant or less efficient locating host patches. Eggs parasitized by T. droozi only occurred in traps with eggs parasitized by T. coloradensis, suggesting that it may be responding to kairomones emitted by T. coloradensis. In contrast, neither the number nor sex ratio of T. coloradensis emerging from eggs in traps with T. droozi differed from those in traps without this congeneric. Secondary sex ratios of all three species were significantly female biased. Our study suggests that only T. coloradensis has the potential to regulate hemlock looper populations.
Use of ß‐blocker therapy to prevent primary bleeding of esophageal varices
Authors: Tursi Tammy 
Published: November 2010

Abstract Purpose: The purpose of this article is to educate nurse practitioners about the pathophysiology surrounding the development of portal hypertension and the effective use of nonselective ß‐blockers to prevent primary bleeding and decrease the mortality risk. Data sources: The articles included were retrieved via ISI Web of Science using the years 2004–2009 and key words cirrhosis, portal hypertension, esophageal varices, and beta‐blockers. This information included scholarly books, journal reviews, retrospective chart reviews, and prospective randomized studies. Conclusions: Cirrhosis is the leading cause of portal hypertension in Europe and North America. Esophageal varices are a result of the portosystemic collaterals the body develops to decompress the portal system. Hemorrhage from esophageal varices is a major cause of morbidity and mortality. Prevention of a primary bleed is the goal of therapy and is accomplished with nonselective ß‐blockers. Implications for practice: Very few patients with portal hypertension and esophageal varices are on ß‐blockers. Use of nonselective ß‐blockers has been found to lower portal pressure and decreases the risk of bleeding from esophageal varices and therefore decreases mortality. Patients unable to use ß‐blockers can undergo endoscopic variceal ligation as an alternate method to reduce risk of bleeding.
The effects of preoperative exercise therapy on postoperative outcome: a systematic review
Authors: Valkenet Karin , van de Port Ingrid GL , Dronkers Jaap J , de Vries Wouter R , Lindeman Eline , Backx Frank JG 
Published: November 2010

Objective: To summarize the current evidence on the effects of preoperative exercise therapy in patients awaiting invasive surgery on postoperative complication rate and length of hospital stay. Data sources: A primary search of relevant key terms was conducted in the electronic databases of PubMed, EMBASE, PEDro and CINAHL. Review methods: Studies were included if they were controlled trials evaluating the effects of preoperative exercise therapy on postoperative complication rate and length of hospital stay. The methodological quality of included studies was independently assessed by two reviewers using the PEDro scale. Statistical pooling was performed when studies were comparable in terms of patient population and outcome measures. Results were separately described if pooling was not possible. Results: Twelve studies of patients undergoing joint replacement, cardiac or abdominal surgery were included. The PEDro scores ranged from 4 to 8 points. Preoperative exercise therapy consisting of inspiratory muscle training or exercise training prior to cardiac or abdominal surgery led to a shorter hospital stay and reduced postoperative complication rates. By contrast, length of hospital stay and complication rates of patients after joint replacement surgery were not significantly affected by preoperative exercise therapy consisting of strength and/or mobility training. Conclusion: Preoperative exercise therapy can be effective for reducing postoperative complication rates and length of hospital stay after cardiac or abdominal surgery. More research on the utility of preoperative exercise therapy and its long-term effects is needed as well as insight in the benefits of using risk models.