bluuebunny/crossref_metadata_2025 huggingface dataset:
Phononic crystals operating in the gigahertz range with extremely wide band gaps
Authors: Soliman Y. M. , Su M. F. , Leseman Z. C. , Reinke C. M. , El-Kady I. , Olsson R. H.
Published: November 2010

Phononic crystals have numerous potential applications including use as filters and oscillators in communications systems and as acoustic isolators for resonant sensors such as gyroscopes. These applications are based on the ability of phononic crystals to exhibit elastic band gaps, frequency bands where the propagation of acoustic waves is forbidden. Here, we focus on solid-solid phononic crystals (solid inclusions in a solid matrix), since they typically exhibit wider band gaps than those observed with air-solid phononic crystals (air inclusions in a solid matrix). We present a micromachined solid-solid phononic crystal operating at 1.4 GHz center frequency with an ultrawide 800 MHz band gap.
Dynamic annealing versus thermal annealing effects on the formation of hydrogen-induced defects in silicon
Authors: Di Z. F. , Huang M. Q. , Wang Y. Q. , Nastasi M.
Published: November 2010

The influence of dynamic and thermal annealing on hydrogen platelet formation in silicon have been studied. For cryogenic and room temperature implantations, where dynamic annealing is suppressed, hydrogen platelets form upon subsequent thermal annealing on primarily (100) planes. However, under high temperature implantation (dynamic annealing), a high density hydrogen platelet network consisting of both (111) platelets and (100) platelets is observed. Our findings demonstrate that hydrogen implantation under dynamic annealing conditions leads to a modification of the implantation-induced stress, which eventually guide the nucleation and growth of hydrogen-induced platelets.
Chemically accurate coarse graining of double-stranded DNA
Authors: Savelyev Alexey , Papoian Garegin A.
Published: November 2010

Coarse-grained (CG) modeling approaches are widely used to simulate many important biological processes involving DNA, including chromatin folding and genomic packaging. The bending propensity of a semiflexible DNA molecule critically influences these processes. However, existing CG DNA models do not retain a sufficient fidelity of the important local chain motions, whose propagation at larger length scales would generate correct DNA persistent lengths, in particular when the solution’s ionic strength is widely varied. Here we report on a development of an accurate CG model for the double-stranded DNA chain, with explicit treatment of mobile ions, derived systematically from all-atom molecular dynamics simulations. Our model generates complex local motions of the DNA chain, similar to fully atomistic dynamics, leading also to a quantitative agreement of our simulation results with the experimental data on the dependence of the DNA persistence length on the solution ionic strength. We also predict a structural transition in a torsionally stressed DNA nanocircle as the buffer ionic strength is increased beyond a threshold value.
Phytophthora-ID.org: A Sequence-Based Phytophthora Identification Tool
Authors: Grünwald Niklaus J. , Martin Frank N. , Larsen Meredith M. , Sullivan Christopher M. , Press Caroline M. , Coffey Michael D. , Hansen Everett M. , Parke Jennifer L.
Published: November 2010

Contemporary species identification relies strongly on sequence-based identification, yet resources for identification of many fungal and oomycete pathogens are rare. We developed two web-based, searchable databases for rapid identification of Phytophthora spp. based on sequencing of the internal transcribed spacer (ITS) or the cytochrome oxidase (cox) 1 and 2 spacer region, followed by BLAST searching the databases. Both databases are highly selective. For ITS, only sequences associated with published Phytophthora spp. descriptions or classic Phytophthora phylogenetics references are included. For the cox spacer region, only data obtained by resequencing select isolates reported in published work were included. Novel taxa tentatively named are selectively included in the database and labeled as Phytophthora taxon “X”; as in, for example, P. taxon “asparagi”. The database was validated with 700 Phytophthora isolates collected from nursery environments during 2006 to 2009. This resource, found at www.Phytophthora-ID.org , is a robust and validated tool for molecular identification of Phytophthora spp. and is regularly being updated.
Comparison of the Surface Coat Proteins of the Pine Wood Nematode Appeared During Host Pine Infection and In Vitro Culture by a Proteomic Approach
Authors: Shinya Ryoji , Morisaka Hironobu , Takeuchi Yuko , Ueda Mitsuyoshi , Futai Kazuyoshi
Published: November 2010

Pine wilt disease, caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, has become of worldwide quarantine concern in recent years. Here, we disclosed the surface coat (SC) proteins of the PWN which are thought to be one of the key components in pine wilt development. This is the first report that focused on the SC proteins and thoroughly identified those proteins of a plant-parasitic nematode using the proteomic approach. In this study, SC protein profiles were compared for PWNs grown on the fungus Botrytis cinerea and in host pine seedlings. The results demonstrated that the gross amount of PWN SC proteins drastically increased during infection of the host pine. Thirty-seven protein bands showed significant quantity differences between fungus-grown and host-origin PWNs, and were used for identification by matrix-assisted laser desorption ionization time of flight mass spectrometry analysis. These included several proteins that are presumed to be involved in the host immune response; for example, regulators of reactive oxygen species (ROS) and a ROS scavenger. These results might suggest that the PWN SC proteins are crucial in modulating or evading host immune response. Our data provide a new insight into the mechanism of pine wilt disease and the biological role of the SC proteins of plant-parasitic nematodes.
The migrating motor complex modulates intestinal motility response and rate of gastric emptying of caloric meals
Authors: MEDHUS A. , SANDSTAD O. , BREDESEN J. , HUSEBYE E.
Published: November 2010

Abstract The present study elucidates whether the phase of the migrating motor complex (MMC) present at the moment of food intake modulates postprandial motor response and rate of gastric emptying of caloric meals. Eight healthy male volunteers with a mean age of 26 years were examined twice. During water‐perfused gastroduodenal manometry, a liquid meal with paracetamol added as a marker was orally administered during phase I and late phase II. Paracetamol appeared in serum 14.1 ± 3.8 min and 9.1 ± 4.0 (mean ± SD) min, respectively, after intake of the meal (P < 0.02). The area under the curve of s‐paracetamol until 25 min after intake was 232 ± 169 μmoll‐1 min and 362 ± 130 (P < 0.05), respectively. When taken during late phase II, a phase III‐like activity occurred within 2.1 ± 1.3 min in the duodenum, and was succeeded by quiescence. During phase I, the meal invariably initiated irregular contractions within 4 min. The phase of MMC during which a caloric meal is ingested modulates duodenal motor response and rate of gastric emptying during the initial postprandial period. Initial postprandial motor activity thus represents the combined effect of nutrient stimulation and the underlying enteric biorhythm as reflected by phase of MMC.
Gallbladder motility before and after Billroth II gastric resection
Authors: CHILOIRO M. , PEZZOLLA F. , RIEZZO G. , MASELLI M. A. , LORUSSO D.
Published: November 2010

The 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.
Effects of the corticotropin‐releasing factor (CRF) on rectal afferent nerves in humans
Authors: LEMBO T. , PLOURDE V. , SHUI Z. , FULLERTON S. , MERTZ H. , TACHE Y. , SYTNIK B. , MUNAKATA I. , Mayer Emeran A.
Published: November 2010

AbstractCorticotropin‐releasing factor (CRF) released in the gastrointestinal mucosa from immune cells or enterochromaffin cells may play a role in the modulation of rectal afferent function. In the current study we evaluated the effects of peripherally administered CRF on afferent mechanisms in the human rectum. We used rectal balloon distention in seven healthy volunteers to evaluate the effect of CRF (1 μ/kg) on visceral afferents originating in the rectum which are involved in the following functions: thresholds and intensity of conscious perception, receptive relaxation, reflex inhibition of internal anal sphincter and a viscerosomatic reflex. Rectal mechanoreceptors were stimulated either by distending the rectum using a volume ramp (40 and 400 mL/min), or by intermittent phasic distention. CRF decreased the thresholds and increased the intensity for the sensation of discomfort in response to both ramp and phasic distention. During slow ramp distention, CRF also lowered the stool threshold. CRF increased rectal compliance during slow ramp distention without affecting the rate of receptive relaxation or the inflection point of the compliance curve. CRF had no effect on viscerosomatic referral patterns, or on the rectoanal inhibitory reflex. These findings are consistent with a dual effect of CRF on afferent pathways mediating perception of aversive rectal sensations, and on rectal smooth muscle.
High resolution electrical mapping in the gastrointestinal system: initial results
Authors: LAMMERS W. J. E. P. , STEPHEN B. , ARAFAT K. , MANEFIELD G. W.
Published: November 2010

High resolution electrical mapping in the gastrointestinal system entails recording from a large number of extracellular electrodes simultaneously. It allows the collection of signals from 240 individual sites which are then amplified, filtered, digitized, multiplexed and stored on tape. After recording, periods of interest can be analysed and the original sequence of activity reconstructed. This technology, originally developed to study normal rhythms and abnormal dysrhythmias in the heart, has been modified to allow recordings from the gastrointestinal tract. In this report, initial results are presented describing the origin and propagation of the slow wave in the isolated stomach and the isolated duodenum in the cat. These results show that in both organs it not uncommon to have more than one focus active during a single cycle. The conduction of slow waves from such a multiple pacemaker environment can become quite complex, and this may play a role in determining the contractile pattern in these organs.
Effect of glucose and lipids on intestinal absorption of sorbitol: role of gastric emptying
Authors: BEAUGERIE L. , LÉMANN M. , JIAN R. , FLOURIÉ B. , RAIN J.‐D. , RAMBAUD J.‐C.
Published: November 2010

The aim of our study was to test the hypothesis that the better absorption of sorbitol when ingested with glucose could be related to a delayed gastric emptying. We tested the effect of the ingestion of glucose and lipids on the gastric emptying and intestinal absorption of sorbitol in six healthy volunteers, using gastric scintigraphy and hydrogen breath test. After an overnight fast, subjects ingested in random order, on 48‐h test periods separated by at least one week, the following solutions: (a) 20 g sorbitol alone; (b) 20 g sorbitol and 20 g glucose; (c) 20 g sorbitol and 9 g lipids. Isotopic acquisitions were taken for 3 h following the ingestion of sorbitol labelled with 111Indium. Hydrogen concentration was measured in end‐expiratory samples during 5 h, and the areas under the breath hydrogen curve, reflecting the amounts of sorbitol unabsorbed in the small bowel, were compared between periods. Mean area under the curve was 397 ± 159 when sorbitol was ingested alone, and this was significantly lower when ingested with glucose or lipids (313 ± 181 and 337 ± 135, respectively; P < 0.05). The three curves of sorbitol gastric emptying differed significantly from each other, the gastric emptying being the slowest for sorbitol plus lipids, and the fastest for sorbitol taken alone. We found a positive correlation between the half‐emptying time and the hydrogen areas under the curve (r = 0.46, P = 0.05). In conclusion, our study demonstrates that adding glucose or lipids to a solution of sorbitol slows the gastric emptying of sorbitol, resulting in a better intestinal absorption of sorbitol.
Pathogenesis of IgA nephropathy
Authors: ES LA van , FIJTER JW de , DAHA MR
Published: November 2010

Summary: Although a genetic predisposition to IgA nephropathy can be documented in a minority of patients, the majority of cases are sporadic. The frequent association with mucosal infections suggest the aetiologic involvement of microbial antigens. However, no particular bacterial or viral strain has clearly been implicated. The involvement of mesangial or endothelial autoantigens has been suggested but not proven in a majority of cases. Most patients have a significantly higher memory repertoire of IgA forming B‐lymphocytes in their bone marrow associated with high plasma levels of IgA1 while the mucosally stimulated IgA response against recall antigens is augmented, the mucosal and plasma IgA response after mucosal stimulation by neoantigen is significantly reduced or absent. These observations suggest that IgA nephropathy patients have a defect in raising a mucosal IgA response against novel microbial antigens and that they will suffer from recurrent mucosal infections until they have developed a large enough repertoire of memory B‐cells to protect their mucosal surfaces. As a consequence of the recurrent stimulation of the IgA immune system, high levels of plasma IgA are found. The mechanism of IgA deposit formation in the mesangium is unknown. The ensuing inflammatory reaction in the glomeruli may vary from mild to severe, but usually the disease has an indolent course. The progression of IgA nephropathy to renal failure is clinically the most important complication. Recent observations on the role of cytokines in the pathogenesis of interstitial infiltration, interstitial fibrosis and tubular atrophy have created the opportunity to study and manipulate the process of renal scarring and the progression to renal failure.
Pattern of proteinuria in IgA nephropathy
Authors: WOO KT , LAU YK , LEE Grace SL , WONG KS , WEI SS , CHIANG Gilbert SC , LIM CH
Published: November 2010

Summary: Proteinuria is one of the bad prognostic indices in IgA nephritis (IgAN). This study compares the pattern of protein excretion in 10 patients with IgAN (IA) with that 5 years later (IB), when they developed renal impairment or hypertension. The pattern of proteinuria was analysed by SDS‐PAGE and isoelectric focusing (IEF) and assayed for orosomucoid, α‐1‐microglobulin, retinol‐binding protein, lysozyme, beta‐2‐microglobulin and N‐acetyl‐β‐D‐glucosaminidase activity. The data suggest that the changing pattern of proteinuria from IgA1 to IgA2 may reflect hyperfiltration as well as tubular injury.
Immunological aspects of IgA nephropathy
Authors: KIM Myung Jae , HONG Seong Pyo
Published: November 2010

Summary: IgA nephropathy (IgAN) is one of the most common primary renal diseases, and can be readily diagnosed by finding glomerular IgA deposits as either the dominant or codominant immunoglobulin on immunofluorescence microscopy. Despite some contradictory results about the nature and origin of IgA, it is generally accepted that the deposited IgA is polymeric and belongs to the IgA, subclass and systemic compartment is the source of circulating polymeric‐IgA in IgAN. Because IgAN presents with asymptomatic microscopic haematuria or with episodic gross haematuria following upper respiratory and gastrointestinal disturbance, various environmental respiratory or gastrointestinal infectious agents and dietary antigens are suggested. Until now, however, it has not been possible to unequivocally identify specific antigens that are responsible for the formation of mesangial IgA deposits in patients with IgAN. Overproduction or delayed clearance of IgA as observed in patients and in animal models and in those processes, polyclonal stimulation of immunoglobulin production, with structural abnormalities of IgA, seems to play an important role. The mechanism responsible for the mesangial deposition of IgA is still unclear. The codeposition of IgA, C3 and properdin without Clq and C4 suggested a possible activation of the alternative pathway by IgA‐containing immune complexes. To sum up, in IgAN the predominant antibody appears to be composed of polymeric‐IgA1 originating in the systemic compartment. The deposition of polymeric‐IgA1 in the mesangium and the activation of the alternative pathway of complement are probably crucial in the induction of the inflammatory lesions in the glomeruli and the development of haematuria in IgAN.
Polymorphism in IgA nephropathy
Authors: LIU Zhi‐Hong , LI Lei‐Shi
Published: November 2010

Summary: IgA nephropathy (IgAN) is polyphormic in its clinical manifestation, course and prognosis. Patients with isolated IgA deposit in glomeruli tend to have a high incidence of macroscopic haematuria and carry a better prognosis. In contrast, patients with deposits of IgA and IgG and IgM have a higher incidence of nephrotic syndrome and hypertension. In parallel, patients with IgA and IgG and IgM tend to have more glomerulosclerosis and tubulointestitial lesions. Recently, the angiotensin converting enzyme (ACE) gene polymorphism and its association in disease risk provided interesting exploration leading us to speculate about a possible mechanism to explain the variation in the rate of progression of IgAN; although, the results are still controversial. The variability of plasma ACE concentration has been shown to be associated with an insertion/deletion polymorphism. The frequencies of ACE genotype in 177 Chinese patients with IgAN has been observed. We found that patients with IgAN showed a higher frequency of DD genotype than normal population. In contrast to the previous reports, we did not find any association between ACE genotype and the rate of progression of IgAN. As different genotypes of IL‐1 receptor antagonist (IL‐1 ra) are also responsible for the circulating levels of IL‐1 ra, the polymorphism of IL‐1 ra gene has been analyzed in 100 IgAN patients. There was no significant difference in the frequency of IL1RN*2 allele between normal subjects and IgAN. However, patients with recurrent macroscopic haematuria showed a higher carriage rate of IL1RN*2. Hereditable factors, in combination with a number of recognized environmental risk factors, are important determinants of the pathogenesis and natural history of IgAN. The notion that the gene polymorphism might be responsible for the clinical features and progression of IgAN is both intriguing and provocative. The lessons from previous multiple small size studies have produced conflicting results illustrating the need for observation of large numbers of cases in further studies to verify these observed associations.
Role of cytokines in the progression of renal damage in IgA nephropathy
Authors: SCHENA FP
Published: November 2010

Summary: IgA nephropathy, or Berger's disease (IgAN), is a worldwide disease which is characterized by a slowly progressive loss of renal function accompanied by decreasing kidney size with the development of glomerulosclerosis and interstitial fibrosis. Immunologic and non‐immunologic factors are implicated in the progression of renal damage, since they are potent inducers in stimulating glomerular, tubular and interstitial cells and non‐resident cells to produce free oxygen radicals, cytokines, growth factors, chemokines, etc. Recent data from our laboratory and other groups, synthesized in this review, have demonstrated the remarkable involvement of these humoral factors in the progression of renal damage in IgAN patients. Therefore, prospective therapeutic approaches have been suggested in blocking the inflammatory mediators during the pathophysiologic sequelae of immune and non‐immune mechanisms which may intervene in the outcome of the disease.
The role of integrins in IgA nephropathy
Authors: COPPO R. , PERUZZI L. , CIRINA P. , AMORE A. , TRUSOLINO L. , BASSO G. , LINARI C. , SHEN Y. , MARCHISIO PC
Published: November 2010

Summary: The complicated network of immune reactions leading to mesangial cell activation and glomerular sclerosis in IgA nephropathy (IgAN) involves interactions between infiltrating cells, mesangial cells and mesangial matrix which are mediated by adhesion molecules. Integrin expression on mesangial cells in culture has recently been described. In the present work we investigated whether integrin expression on cultured human mesangial cells (MC) and mesangial matrix production could be modulated by mesangial matrix components, or by other proteins which may come into contact with MC during pathologic conditions, such as fibrinogen and von Willebrand factor. Moreover, we evaluated the effects induced by polymeric IgA or aggregated IgA or mixed IgA/IgG aggregates on integrin expression. To elucidate a possible role for abnormally glycosylated IgA, we tested IgA pretreated with various enzymes specific for carbohydrate residue components of the side carbohydrate chains of IgA molecules. We found that cultured mesangial cells, highly express the αv β3 integrin receptor for vitronectin and to a lesser extent the α3 β1 receptor for fibronectin and collagens. Among these integrins, αv β3 is modulated by matrix components and particularly enhanced when cells are incubated with proteins which can be abnormally present in the mesangial area, such as fibrinogen, collagen I and von Willebrand factor. IgA and aggregated IgA can modify integrin expression, inducing a decrease in α3 β1 and an increase in αv expression. Moreover, sugars can affect these interactions, since desialylated IgA enhance the expression of integrin β3 chain on cultured mesangial cells and sialic acid per se strongly inhibits it. Conversely, other sugars, represented in the carbohydrate chains of IgA1 including mannose and N‐acetylgalactosamine, were found to enhance αv expression. Our data suggest that the interactions of native polymeric IgA, IgA or IgA/IgG aggregates, as well as IgA with altered glycosylation may result in structural rearrangement of mesangial integrins, possibly reflecting on mesangial matrix composition.
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

We 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

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.
Horizontal Capacity of Embedded Suction Anchors in Clay
Authors: Bang S. , Jones K. , Kim Y. S. , Cho Y.
Published: November 2010

The embedded suction anchor (ESA) is a type of permanent offshore foundation that is installed by a suction pile. The primary factors influencing the horizontal pullout capacity of an ESA include the loading point, the soil type, the embedment depth, and the addition of flanges. The main purpose of this study is to develop an analytical solution that is capable of estimating the horizontal pullout capacity of ESAs with the loading point being anywhere along its length with or without flanges. An analytical solution has been developed to estimate the horizontal pullout capacity of embedded suction anchors in clay seafloor. Validation has been made through comparisons with the centrifuge model test results. Results indicate that the horizontal pullout capacity of the embedded suction anchor in clay increases, reaches its peak, and then starts to decrease as the point of the load application moves downward. The effect of flanges on the horizontal pullout capacity is also found to be significant. The horizontal pullout capacity is a direct function of the loading point. The horizontal pullout capacity increases as the loading point moves downward and the maximum pullout capacity is obtained when the loading point is approximately at the mid-depth. The increase in horizontal pullout capacity can be significant, i.e., more than twice in magnitude when the maximum pullout capacity is compared with that associated with the loading point near the top or tip.
CONSERVATION LAWS OF SOME NON-VARIATIONAL PERTURBED PDE'S VIA A PARTIAL VARIATIONAL APPROACH
Authors: JOHNPILLAI A. G. , KARA A. H. , MAHOMED F. M.
Published: November 2010

We show how one can construct approximate conservation laws of systems of perturbed or approximate partial differential equations that are not derivable by the variational principle but are approximate Euler–Lagrange in part by using approximate partial Noether operators associated with partial Lagrangians. We investigate perturbed partial differential equations that arise in several important physical applications. Finally, we obtain new approximate conservation laws for these equations.
STRAIN RELAXATION IN SiGe VIRTUAL SUBSTRATE CHARACTERIZED BY HIGH RESOLUTION X-RAY DIFFRACTION
Authors: TAN W. S. , CAI H. L. , WU X. S. , DENG K. M. , CHENG H. H.
Published: November 2010

In this paper, with solid source molecular beam epitaxy technique, Si 1-x Ge x( SiGe ) virtual substrates were deposited on low-temperature-grown Si (LT- Si ) buffer layer, which was doped with Sb . The strain in SiGe virtual substrate was characterized by high resolution X-ray diffraction. Results indicated that Sb -doping in LT- Si can effectively modulate the degree of strain relaxation in SiGe virtual substrate. The segregated Sb on the surface of LT- Si layer acts as surfactant and results in abrupt strain relaxation.
The 2nd workshop on active internet measurements (AIMS-2) report
Authors: claffy kc , Aben Emile , Auge Jordan , Beverly Robert , Bustamante Fabian , Donnet Benoit , Friedman Timur , Fomenkov Marina , Haga Peter , Luckie Matthew , Shavitt Yuval
Published: November 2010

On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. The goals of this workshop were to further our understanding of the potential and limitations of active measurement research and infrastructure in the wide-area Internet, and to promote cooperative solutions and coordinated strategies to addressing future data needs of the network and security research communities. The three-day workshop included presentations, group discussion and analysis, and focused interaction between participating researchers, operators, and policymakers from all over the world. This report describes the motivation and findings of the workshop, and reviews progress on recommendations developed at the 1st Active Internet Measurements Workshop in 2009 [18]. Slides from the workshop presentations are available at [9].
Estimation of the movement of the inter-fragmentary gap of a fractured human femur in the presence of a composite bone plate
Authors: Kim Ju-Ho , Kim Suk-Hun , Chang Seung-Hwan
Published: November 2010

Composite bone plates made of carbon/epoxy prepregs were investigated for obtaining a more uniform strain distribution at the fracture site of human bones through finite element (FE) analysis. The fracture site was modeled by a multilayered structure. One conventional stainless steel bone plate and several composite bone plates were considered for calculating the strain distributions at the fracture site. The average stresses of bones and bone plates were also calculated for the evaluation of the stress-shielding effect. From the results of FE analysis, it was found that the composite bone plate caused an affirmative strain distribution at the fracture site, which stimulated callus generation.
Experimental evaluation and statistical characterization of the strength and strain energy density distribution of Kevlar KM2 yarns: exploring length-scale and weaving effects
Authors: Nilakantan Gaurav , Ahmad Abu Obaid  , Keefe Michael , Gillespie John W.
Published: November 2010

This article experimentally investigates the tensile strength distributions of 600 den Kevlar KM2 yarns under quasi-static tensile loading. The strength distributions were best characterized using the 3-parameter Weibull and generalized Gamma distributions. In order to assess the effects of weaving on the strength distributions, Kevlar yarns were tested from a spool and then compared to yarns extracted from greige and scoured Kevlar fabrics. The weaving process and treatments caused various levels of strength degradation which shifted the strength distributions toward lower strengths. The warp yarns were degraded to a greater extent than the fill yarns. The scouring process induced further strength degradations in the woven fabric. Length-scale effects were studied by using gage lengths varying between 25.4 and 381.0 mm. The strength distributions were observed to shift toward lower strengths with increasing gage lengths. A new distribution function based on a modification to the 3-parameter Weibull distribution is proposed to account for length-scale effects. In addition to the strength distributions, the experimental load—extension plots are used to compute the strain energy density or work-to-break values normalized by the yarn volume, which are then statistically characterized and analyzed in a similar manner.
The Influence of Lubrication on Two-body Abrasive Wear of Sealing Elastomers Under Reciprocating Sliding Conditions
Authors: Mofidi M. , Prakash B.
Published: November 2010

Elastomeric seals are prone to failure caused by abrasion during sliding against rough surfaces. In this research, the two-body abrasive wear of some selected sealing elastomers (nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluoro rubber) in dry and lubricated conditions has been studied. The influence of three different oils (synthetic ester, polyalphaolefin, and mineral oil) on the abrasive wear of the elastomers, at varying normal load and abrasive particle size, has been studied. The results show that, depending on the material, lubricant, abrasive size, and normal load, the abrasive wear of elastomers may increase or decrease in the presence of lubricants, and in most cases, the abrasive wear in the lubricated condition is higher than that in the dry condition. The influence of lubricant on the increase in abrasive wear is more significant during sliding against fine abrasives. Apart from the acrylic rubber, increase in the abrasive wear in presence of the synthetic ester is higher than those in presence of the mineral oil and polyalphaolefin.
Associations Between Depressive Symptom Dimensions and Smoking Dependence Motives
Authors: Mickens Lavonda , Greenberg Jodie , Ameringer Katherine J. , Brightman Molly , Ping Sun  , Leventhal Adam M.
Published: November 2010

Depressive symptoms are heterogeneous and can be parsed into four subdimensions (i.e., positive affect [PA], negative affect [NA], somatic features [SF], and interpersonal problems [IP]) that may have unique associations with the motivation to smoke. This study explored associations between depressive symptom dimensions and 13 theoretically distinct domains of smoking dependence motivation in current cigarette smokers (N = 212; 53% female, mean [M] age = 24 years). Results demonstrated substantial variability in the pattern of motivational correlates across depressive dimensions. Low PA exhibited the narrowest motivational profile, associating with only the tendency to prioritize smoking over other reinforcers. NA demonstrated a broader profile, associating with smoking for affect regulation and cognitive enhancement as well as prioritizing smoking. SF associated with prioritizing smoking and smoking because of cue exposure, craving, and weight control. IP demonstrated the broadest profile, associating with 7 of 13 motivational domains. These findings may assist the tailoring cessation interventions for smokers with depressive symptoms.
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.
Musical “learning styles” and “learning strategies” in the instrumental lesson: Some emergent findings from a pilot study
Authors: Green Lucy
Published: November 2010

This article considers the concepts of “learning style” and “learning strategy”. The former connotes an inbuilt trait which tends to remain fundamental to the way an individual approaches learning. The latter refers to a set of consciously-acquired and applied approaches or tactics designed to achieve a learning task. The article relates these concepts to the field of instrumental music learning, particularly the activity of learning to play by ear. In a pilot study, 15 instrumental students aged 10 to 17, covering eight different instruments, learnt to play pieces by ear. The research strategies and pedagogic methods derive from earlier studies, particularly the adaption of popular musicians’ informal learning practices in classroom contexts. Through participant observation and other qualitative methods, it is suggested that four potential aural “learning styles” emerged: the “impulsive”, the “shot-in-the-dark”, the “practical” and the “theoretical” styles. These are illustrated with qualitative data from lesson transcripts and annotations. They are then distinguished from three further aspects of learning that were apparent: pitch-sense, rhythm-sense and “learning strategies”. I suggest why further research in this area may be beneficial, and finally put forward some reasons why the identification of possible learning styles in relation to music could be of pedagogical significance.
Influence of fiber failure on fatigue hysteresis loops of ceramic matrix composites
Authors: Longbiao Li  , Yingdong Song
Published: November 2010

An analytical methodology has been developed to investigate the influence of fiber failure on fatigue hysteresis loops of ceramic matrix composites in this article. During fatigue loading, matrix cracking, interface debonding and fiber failure occur upon first loading to the fatigue maximum stress. Matrix cracking space and interface debonding length are obtained by matrix statistical cracking model and fracture mechanics interface debonding criterion. Based on the assumption of global load-sharing criterion for the load distribution between the unbroken and broken fibers, an approach to determine fiber failure probability during fatigue loading for the degradation of interface shear stress and fiber strength is developed in this analysis. Upon unloading and subsequent reloading, stress—strain hysteresis loops develop as fiber sliding relative to matrix in the interface debonded region. The unloading interface counter slip length and reloading new slip length are obtained by the fracture mechanics interface debonding criterion. The effects of characteristic fiber strength, fiber Weibull modulus, and fatigue maximum stress on fiber failure during fatigue loading, and then on the shape, location, and area of the fatigue hysteresis loops are investigated. The fatigue hysteresis loops of three different ceramic composites corresponding to different cycles are predicted and agree well with the experimental data.
Mechanical properties of plastic matrix composite materials used in tractor bonnets
Authors: Becenen Nilgün , Eker Bülent , Sahin Mumin
Published: November 2010

The effects of chemical structure of the resin, reinforcement types, material thickness, and post-cure treatment on the mechanical properties of composite material were examined in this study. Composite materials were produced by combining chopped, woven, and felt glass fibers with thermoset plastic-based matrixes. Orthophtalic polyester (polives 701) and bisphenol-A epoxy vinyl ester (polives3401) resins were chopped in combination with a catalyst system composed of MEK-PEROKSIT and cobalt, and were reinforced with chopped, woven, and felt glass fiber. Composite materials were prepared using a hand lay-up method. Half of the prepared composite materials were post-cured, the other half remained non-treated. A total of 75 tests were performed. Tensile, bending, impact, and hardness tests were performed to determine the mechanical properties of the samples. The test results indicated that durable and strong tractor bonnets can be produced using vinyl ester-based matrix material and 90° glass fiber woven reinforcement material, producing two-layered composite material and curing at 50°C, 80°C, and 110° C.
Estimating the Costs of Bad Outcomes for At-Risk Youth and the Benefits of Early Childhood Interventions to Reduce Them
Authors: Cohen Mark A. , Piquero Alex R. , Jennings Wesley G.
Published: November 2010

Although it appears that there is growing interest in early childhood intervention as an effort to reduce crime, resources continue to be funneled toward punishment and incarceration. Considering this and acknowledging earlier cost-based empirical research, the question still remains as to the cost incurred by a lifetime of involvement in crime and experiencing a host of adverse noncrime outcomes. This study provides a review of the literature in search of well-designed early childhood interventions that address a series of socials ills, such as crime and delinquency, educational attainment, drug and alcohol abuse, smoking, child abuse and neglect, poor health outcomes, and teen pregnancy. Furthermore, building on the earlier framework and basic methodology developed by Cohen and recently updated by Cohen and Piquero, this study offers calculations of the present value of lifetime costs imposed on society for each of these various social ills—discounted to the date of birth to put them on comparable terms. The largest cost is imposed by the career criminal (US$2.1-US$3.7 million). Next, the present value costs associated with both drug abuse and alcohol dependence/abuse are roughly the same—about US$700,000 each—whereas child abuse and neglect costs an estimated US$250,000 to US$285,000. Health-related outcomes range from a low US$10,300 for the estimated present value cost of low birth weight to US$127,000, US$144,000, US$187,000, and US$260,000 for coronary heart disease, asthma, diabetes, and smoking, respectively. Finally, the present value cost of teen pregnancy is estimated to range from US$120,000 to US$140,000. Thus, properly designed programs and policies that focus on early childhood intervention have the potential to produce significant social benefits. Study limitations and suggestions for future research are also discussed.
Nonlinear vibration control of functionally graded plate with piezoelectric layers in thermal environment
Authors: Fakhari Vahid , Ohadi Abdolreza
Published: November 2010

In this paper, large amplitude vibration control of functionally graded material (FGM) plates under thermal gradient and transverse mechanical loads using integrated piezoelectric sensor/actuator layers is investigated. In this regard, finite element formulation based on higher order shear deformation plate theory is developed. The von Karman nonlinear strain-displacement relationship is used to account for the large deflection of the plate. The material properties of FGM are assumed to be temperature-dependent and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The temperature field is assumed to be constant in the plane and varied only in the thickness direction of the plate. In order to control the large amplitude vibration of the plate, two control algorithms are employed: classical displacement-velocity feedback control and robust H2 control. Also, the uncertainty which arises from external disturbances (low-frequency sine-wave sensor noise and high-frequency Gaussian white sensor noise) is considered. Active control of both the static deflection due to thermal gradient and dynamic oscillation is studied. Numerical results are presented to investigate the effectiveness of the mentioned control algorithms to control nonlinear vibration and thermally induced deflection of the FGM plate. Also, robustness of the controllers in the face of sensor noise is investigated. Effects of the design parameters on performance of each controller are studied and finally, the two control methods are compared.