bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Immigrant Communities on Foreign-Born Student Achievement
Authors: Conger Dylan , Schwartz Amy E. , Stiefel Leanna
Published: September 2011

This paper explores the effect of the human capital characteristics of co-ethnic immigrant communities on foreign-born students’ math achievement. We use data on New York City public school foreign-born students from 39 countries merged with census data on the characteristics of the immigrant household heads in the city from each nation of origin and estimate regressions of student achievement on co-ethnic immigrant community characteristics, controlling for student and school attributes. We find that the income and size of the co-ethnic immigrant community has no effect on immigrant student achievement, while the percent of college graduates may have a small positive effect. In addition, children in highly English proficient immigrant communities test slightly lower than children from less proficient communities. The results suggest that there may be some protective factors associated with immigrant community members’ education levels and use of native languages.
Immigrants’ Children's Transition to Secondary School in Italy
Authors: Barban Nicola , White Michael J.
Published: September 2011

Choosing a secondary school represents an important step in the lives of students in Italy, in that it has a strong bearing on their ultimate educational achievement and labor force trajectory. In this article, we analyze the effect of generational status and length of residence on the transition to secondary school among immigrants living in Italy. Using data from the ITAGEN2 follow-up, we analyze scholastic results from the middle school final exam and the choice of secondary school among the adolescents in Italy. Children of immigrants are more likely to have inferior outcomes on the middle school exam and to enroll in vocational and polytechnic schools. Our multivariate results indicate that, after controlling for the family's human capital and other key background factors, immigrant students show greater propensity to choose a vocational path. Differences between immigrants and natives in secondary school tracks are also manifested when previous scholastic results are taken into account.
Reducing Vibrio load in Artemia nauplii using antimicrobial photodynamic therapy: a promising strategy to reduce antibiotic application in shrimp larviculture
Authors: Asok Aparna , Arshad Esha , Jasmin C. , Somnath Pai S. , Bright Singh I. S. , Mohandas A. , Anas Abdulaziz
Published: September 2011

We propose antimicrobial photodynamic therapy (aPDT) as an alternative strategy to reduce the use of antibiotics in shrimp larviculture systems. The growth of a multiple antibiotic resistant Vibrio harveyi strain was effectively controlled by treating the cells with Rose Bengal and photosensitizing for 30 min using a halogen lamp. This resulted in the death of > 50% of the cells within the first 10 min of exposure and the 50% reduction in the cell wall integrity after 30 min could be attributed to the destruction of outer membrane protein of V. harveyi by reactive oxygen intermediates produced during the photosensitization. Further, mesocosm experiments with V. harveyi and Artemia nauplii demonstrated that in 30 min, the aPDT could kill 78.9% and 91.2% of heterotrophic bacterial and Vibrio population respectively. In conclusion, the study demonstrated that aPDT with its rapid action and as yet unreported resistance development possibilities could be a propitious strategy to reduce the use of antibiotics in shrimp larviculture systems and thereby, avoid their hazardous effects on human health and the ecosystem at large.
Whole‐cell bacterial bioreporter for actively searching and sensing of alkanes and oil spills
Authors: Zhang Dayi , He Yi , Wang Yun , Wang Hui , Wu Lin , Aries Eric , Huang Wei E.
Published: September 2011

Acinetobacter baylyi ADP1 was found to tolerate seawater and have a special ability of adhering to an oil–water interface of 10–80 µm emulsified mineral and crude oil droplets. These properties make ADP1 an ideal bacterial chassis for constructing bioreporters that are able to actively search and sense oil spill in water and soils. Acinetobacter baylyi bioreporter ADPWH_alk was developed and applied to the detection of alkanes and alkenes in water, seawater and soils. Bioreporter ADPWH_alk was able to detect a broad range of alkanes and alkenes with carbon chain length from C7 to C36. So far, ADPWH_alk is the only bioreporter that is able to detect alkane with carbon chain length greater than C18. This bioreporter responded to the alkanes in about 30 min and it was independent to the cell growth phase because of two point mutations in alkM promoter recognized by alkane regulatory protein ALKR. ADPWH_alk was applied to detect mineral oil, Brent, Chestnut and Sirri crude oils in water and seawater in the range 0.1–100 mg l−1, showing that the bioreporter oil detection was semi‐quantitative. This study demonstrates that ADPWH_alk is a rapid, sensitive and semi‐quantitative bioreporter that can be useful for environmental monitoring and assessment of oil spills in seawater and soils.
A novel method for screening a vertebrate transcriptome for genes involved in carotenoid binding and metabolism
Authors: POINTER M. A. , PRAGER M. , ANDERSSON S. , MUNDY N. I.
Published: September 2011

Carotenoid‐based colour signals are widespread in the animal kingdom and common textbook examples of sexually selected traits. Carotenoid pigments must be obtained through the diet as all animals lack the enzymatic machinery necessary to synthesize them from scratch. Once ingested, carotenoids are metabolized, stored, transported and deposited, and some or all of these processes may be limiting for signal production and thus subjected to social or sexual selection on phenotypic coloration. Very little is known about which genes and physiological pathways are involved in carotenoid pigmentation which is unfortunate, as genetic information would allow us to investigate the biochemical consequences of sexual selection. In this study, we present a transcriptome‐screening technique and apply it to a carotenoid‐signalling bird species, the southern red bishop Euplectes orix, to uncover the gene(s) responsible for the conversion of dietary β‐carotene (orange) to canthaxanthin (bright red). The transcriptome, extracted from the liver of a male entering his breeding moult, is expressed within bacterial cells genetically modified to synthesize beta‐carotene. Effects of expressed E. orix proteins on the structure or amount of β‐carotene are initially detected by eye (based on colour change) and subsequently confirmed by high‐performance liquid chromatography. Here, we demonstrate the validity of the technique and provide a list of candidate genes involved in the carotenoid pigmentation pathway. We believe that this method could be applied to other species and tissues and that this may help researchers uncover the genetic basis of carotenoid coloration in vertebrates.
The impact of cataract on the quantitative, non‐invasive assessment of retinal blood Flow
Authors: Azizi Behrooz , Wong Tien , Wan Jennifer , Singer Shaun , Hudson Chris
Published: September 2011

Purpose:  The aim of the study was to determine the impact of cataract on the quantitative, non‐invasive assessment of retinal blood flow assessed by bidirectional laser Doppler flowmetry and simultaneous vessel densitometry.

Methodology:  Ten patients scheduled for extracapsular cataract extraction using phacoemulsification and intraocular lens implantation between the ages of 61 and 84 (mean age 73 years, SD ± 8) were prospectively recruited. Two visits were required to complete the study; one visit prior to extracapsular cataract extraction and one at least 6 weeks after the surgery to allow for sufficient postoperative recovery. The severity of cataract was documented using the Lens Opacity Classification System (LOCS, III) at the first visit. Retinal arteriolar hemodynamics were measured at both visits using the high‐intensity setting of the Canon Laser Blood Flowmeter.

Results:  All eyes showed no clinical signs of postoperative intraocular inflammation. The quantitative assessment of retinal arteriolar diameter and blood flow were reduced following extracapsular cataract extraction (Wilcoxon signed‐rank test, p = 0.022 and p = 0.028, respectively); however, centreline blood velocity was not significantly changed (Wilcoxon signed‐rank test, p = 0.074). Intraocular pressure was unchanged pre‐ and postcataract extraction.

Conclusions:  Retinal vessel densitometry assessment in the presence of cataract results in the erroneous elevation of the diameter measurement and thereby the calculation of blood flow. The bidirectional Doppler assessment of blood velocity appears to be more robust to light scatter induced by cataract. Care needs to be exercised in the interpretation of studies of retinal vessel diameter or blood flow that utilize similar densitometry techniques.
Nimotuzumab combined with gemcitabine and cisplatin as second‐line chemotherapy for advanced non‐small‐cell lung cancer
Authors: Wang Hua‐qing , Ren Yangang , Qian Zheng‐zi , Fu Kai , Zhang Hui‐lai , Li Wei , Hou Yun , Zhou Shi‐yong , Hao Xi‐shan , Xie Cong‐hua
Published: September 2011

Objective:  To evaluate the efficacy and safety of nimotuzumab combined with gemcitabine and cisplatin as second‐line chemotherapy for advanced non‐small‐cell lung cancer (NSCLC) and to investigate the association of the status of KRAS gene mutation and epidermal growth factor receptor (EGFR) genotype with clinical outcome.

Methods:  Twenty‐eight patients with advanced NSCLC were enrolled in this single center, uncontrolled pilot clinical study. All the patients developed drug resistance or disease progression after first‐line chemotherapy of either a docetaxel + cisplatin regimen or a vinorelbine + cisplatin regimen and then received nimotuzumab combined with gemcitabine and cisplatin as second‐line chemotherapy. Eight cases were stage IIIB and 20 were stage IV. An i.v. dosage regimen of 200 mg of nimotuzumab was given as a single dose, injected into the patient at days 1, 8 and 15; i.v. gemcitabine was injected at a dose of 1000 mg/m2 at days 1 and 8 and cisplatin (25 mg/m2 i.v.) at days 1, 2 and 3. Each patient received four or more therapeutic cycles. The efficacy and toxic reactions were evaluated, as well as time to progression and overall survival.

Results:  In total, 28 patients with advanced NSCLC received 101 therapeutic cycles. The mean cycle number was 3.6. Median time to progression was 4.9 (2.5–6.5) months; median overall survival and 1‐year survival rate were 9.8 months and 48.5%, respectively. There was one case of complete response, six cases of partial response, 11 cases of stable disease and 10 cases of progressive disease. Response rate was 25%, and clinical benefit rate was 64.3%. Major toxic reactions were bone marrow suppression and gastrointestinal reaction. Only one patient developed grade I acneiform eruption.

Conclusion:  Nimotuzumab combined with gemcitabine and cisplatin as second‐line chemotherapy for advanced NSCLC was active and well‐tolerated in this setting. Patients with EGFR amplification and KRAS gene wild type had a better prognosis. Prospective, randomized, controlled, large‐scale clinical studies are needed to confirm the results.
Rapid reduction of hepatitis C virus‐Core protein in the peripheral blood improve the immunological response in chronic hepatitis C patients
Authors: Kondo Yasuteru , Ueno Yoshiyuki , Wakui Yuta , Ninomiya Masashi , Kakazu Eiji , Inoue Jun , Kobayashi Koju , Obara Noriyuki , Shimosegawa Tooru
Published: September 2011

Aim:  The extracellular hepatitis C virus (HCV)‐antigen, including HCV‐Core protein, can suppress immune cells. Recently, the efficacy of double filtration plasmapheresis (DFPP) for chronic hepatitis C (CHC) was reported. However, the mechanism of efficacy of DFPP might not be only the reduction of HCV but also the effect of immune cells via direct and/or indirect mechanisms. The aim of this study is to analyze the virological and immunological parameters of difficult‐to‐treat HCV patients treated with DFPP combined with Peg‐interferon and RBV (DFPP/Peg‐IFN/RBV) therapy.

Methods:  Twelve CHC patients were enrolled and treated with DFPP/Peg‐IFN/RBV therapy. The immunological, virological and genetic parameters were studied.

Results:  All patients (4/4) treated with the major IL28B allele (T/T) could achieve complete early virological response (EVR). The amounts of HCV‐Core antigen in the peripheral blood of EVR patients treated with DFPP/Peg‐IFN/RBV rapidly declined in comparison to those of late virological response (LVR) patients treated with DFPP/Peg‐IFN/RBV and EVR patients treated with Peg‐IFN and RBV (Peg‐IFN/RBV). The amount of IFN‐γ produced from peripheral blood gradually increased. On the other hand, the amount of IL10 gradually decreased in the EVR patients. The frequencies of HCV‐Core binding on CD3+ T cells rapidly declined in EVR patients treated with DFPP/Peg‐IFN/RBV therapy. Moreover, the distributions of activated CD4+and CD8+ T cells and CD16‐CD56 high natural killer cells were significantly changed between before and after DFPP.

Conclusions:  The rapid reduction of HCV‐Core antigens and changes in the distribution of lymphoid cells could contribute to the favorable immunological response during DFPP/Peg‐IFN/RBV therapy.
The Efficacy and Safety of a Novel Lipophilic Formulation of Methimazole for the Once Daily Transdermal Treatment of Cats with Hyperthyroidism
Authors: Hill K.E. , Gieseg M.A. , Kingsbury D. , Lopez‐Villalobos N. , Bridges J. , Chambers P.
Published: September 2011

Background

Previous studies on transdermal methimazole have used pluronic lecithin organogel as the vehicle. This might not be the most suitable vehicle for a lipophilic drug, such as methimazole.

Hypothesis/Objectives

Once daily transdermal administration of a novel lipophilic formulation of methimazole is as safe and effective as oral carbimazole in treating hyperthyroidism in cats.

Animals

Forty‐five client‐owned cats diagnosed with hyperthyroidism.

Methods

Prospective study. Cats with newly diagnosed, untreated hyperthyroidism were treated with carbimazole (5 mgPO, q12h) or methimazole (10 mg) applied to the inner pinnae q24h. Cats were examined after 0, 1, 4, 8, and 12 weeks of treatment. Clinical signs, body weight, systolic blood pressure, hematologic, serum biochemical and urine parameters, total serum thyroxine concentrations (TT4), and serum methimazole concentrations were recorded.

Results

No significant differences between groups were detected at day 0. Both formulations were effective in treating hyperthyroidism. No significant differences were detected in thyroxine concentrations, body weight, blood pressure, heart rate, alkaline phosphatase, alanine aminotransferase, creatinine, urea, and urine specific gravity (USG) between groups. The serum methimazole concentrations correlated poorly withTT4‐concentrations in both groups.

Conclusions and Clinical Importance

In this 12‐week trial, once daily application of a novel formulation of transdermal methimazole applied to the pinnae was as effective and safe as twice daily oral carbimazole in the treatment of cats with hyperthyroidism. This novel formulation and transdermal application could have practical advantages to some pet owners.
Association between Body Condition and Survival in Dogs with Acquired Chronic Kidney Disease
Authors: Parker V.J. , Freeman L.M.
Published: September 2011

Background

Obesity in people with chronic kidney disease (CKD) is associated with longer survival. The purpose of this study was to determine if a relationship exists between body condition score (BCS) and survival in dogs with CKD.

Hypothesis/Objectives

Higher BCS is a predictor of prolonged survival in dogs with CKD.

Animals

One hundred dogs were diagnosed with CKD (International Renal Interest Society stages II, III or IV) between 2008 and 2009.

Methods

Retrospective case review. Data regarding initial body weight and BCS, clinicopathologic values and treatments were collected from medical records and compared with survival times.

Results

For dogs with BCS recorded (n = 72), 13 were underweight (BCS = 1–3; 18%), 49 were moderate (BCS = 4–6; 68%), and 10 were overweight (BCS = 7–9; 14%). For dogs with at least 2 body weights recorded (n = 77), 21 gained weight, 47 lost weight, and 9 had no change in weight. Dogs classified as underweight at the time of diagnosis (median survival = 25 days) had a significantly shorter survival time compared to that in both moderate (median survival = 190 days; P < .001) and overweight dogs (median survival = 365 days; P < .001). There was no significant difference in survival between moderate and overweight dogs (P = .95).

Conclusions and Clinical Importance

Higher BCS at the time of diagnosis was significantly associated with improved survival. Further research on the effects of body composition could enhance the management of dogs with CKD.
Metal/sulfide–silicate intergrowth textures in EL3 meteorites: Origin by impact melting on the EL parent body
Authors: Van NIEKERK Deon , KEIL Klaus
Published: September 2011

Abstract– We document the petrographic setting and textures of Fe,Ni metal, the mineralogy of metallic assemblages, and the modal mineral abundances in the EL3 meteorites Asuka (A‐) 881314, A‐882067, Allan Hills 85119, Elephant Moraine (EET) 90299/EET 90992, LaPaz Icefield 03930, MacAlpine Hills (MAC) 02635, MAC 02837/MAC 02839, MAC 88136, Northwest Africa (NWA) 3132, Pecora Escarpment 91020, Queen Alexandra Range (QUE) 93351/QUE 94321, QUE 94594, and higher petrologic type ELs Dar al Gani 1031 (EL4), Sayh al Uhaymir 188 (EL4), MAC 02747 (EL4), QUE 94368 (EL4), and NWA 1222 (EL5). Large metal assemblages (often containing schreibersite and graphite) only occur outside chondrules and are usually intergrown with silicate minerals (euhedral to subhedral enstatite, silica, and feldspar). Sulfides (troilite, daubréelite, and keilite) are also sometimes intergrown with silicates. Numerous authors have shown that metal in enstatite chondrites that are interpreted to have been impact melted contains euhedral crystals of enstatite. We argue that the metal/sulfide–silicate intergrowths in the ELs we studied were also formed during impact melting and that metal in EL3s thus does not retain primitive (i.e., nebular) textures. Likewise, the EL4s are also impact‐melt breccias. Modal abundances of metal in the EL3s and EL4s range from approximately 7 to 30 wt%. These abundances overlap or exceed those of EL6s, and this is consistent either with pre‐existing heterogeneity in the parent body or with redistribution of metal during impact processes.
Magnetism and mineralogy of Almahata Sitta polymict ureilite (= asteroid 2008 TC3): Implications for the ureilite parent body magnetic field
Authors: HOFFMANN Viktor H. , HOCHLEITNER Rupert , TORII Masayuki , FUNAKI Minoru , MIKOUCHI Takashi , KALIWODA Melanie , JENNISKENS Peter , SHADDAD Muawia H.
Published: September 2011

Abstract– The Almahata Sitta meteorite is the first case of recovered extraterrestrial material originating from an asteroid that was detected in near Earth space shortly before entering and exploding in the high atmosphere. The aims of our project within the 2008 TC3 consortium were investigating Almahata Sitta’s (AS) magnetic signature, phase composition and mineralogy, focussing on the opaque minerals, and gaining new insights into the magnetism of the ureilite parent body (UPB). We report on the general magnetic properties and behavior of Almahata Sitta and try to place the results in context with the existing data set on ureilites and ureilite parent body models. The magnetic signature of AS is dominated by a set of low‐Ni kamacites with large grain sizes. Additional contributions come from micron‐sized kamacites, suessite, (Cr) troilite, and daubreelite, mainly found in the olivine grains adjacent to carbon‐rich veins. Our results show that the paleomagnetic signal is of extraterrestrial origin as can be seen by comparing with laboratory produced magnetic records (IRM). Four types of kamacite (I–IV) have been recognized in the sample. The elemental composition of the ureilite vein metal Kamacite I (particularly Co) clearly differs from the other kamacites (II‐IV), which are considered to be indigenous. Element ratios of kamacite I indicate that it was introduced into the UPB by an impactor, supporting the conclusions of Gabriel and Pack (2009).
Glucagon‐like peptide‐1 secretion by direct stimulation of L cells with luminal sugar vs non‐nutritive sweetener
Authors: Sakurai Kenichi , Lee Eun Young , Morita Asuka , Kimura Sadao , Kawamura Harukiyo , Kasamatsu Atsushi , Shiiba Masashi , Yabe Daisuke , Yokote Koutaro , Miki Takashi
Published: September 2011

Aims/Introduction:  Oral ingestion of carbohydrate triggers secretion of glucagon‐like peptide (GLP)‐1, which inhibits the postprandial rise in blood glucose levels. However, the mechanism of carbohydrate‐induced GLP‐1 secretion from enteroendocrine L cells remains unclear. In the present study, GLP‐1 secretion was examined by meal tolerance tests of healthy Japanese volunteers.

Materials and Methods:  Twenty‐one healthy Japanese men participated in the study. The meal tolerance test was performed with modified nutrient compositions, with or without pretreatment with the α‐glucosidase inhibitor acarbose, or with substitution of sucrose with an equivalent dose of sweeteners in the meal. Blood concentrations of glucose, insulin, GLP‐1, and apolipoprotein (Apo) B‐48 were measured.

Results:  GLP‐1 secretion started concomitant with the increase in blood glucose levels 10 min after meal ingestion. Insulin secretion started at 5 min, before the increase in blood glucose levels, reflecting the contribution of direct nutrient stimulation on the former parameter and neural regulation in the latter. Carbohydrate retention in the gut lumen induced by acarbose pretreatment extended postprandial GLP‐1 secretion and negated the increase in serum ApoB‐48 levels. GLP‐1 secretion was markedly decreased by a reduction in the amount of sucrose in the meal and was not restored by an equivalent dose of sweeteners used to compensate for the sweet taste.

Conclusions:  The results indicate that direct stimulation of L cells with sugar, but not sweetener, is required for carbohydrate‐induced GLP‐1 secretion. In addition, inhibition of digestion of dietary carbohydrate by α‐glucosidase inhibitors may prevent postprandial hyperglycemia by increasing GLP‐1 secretion and by inhibiting glucose absorption. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00163.x, 2011)
Infertility in a mare with a chronic uterine tear, diagnosis and successful standing hand‐assisted laparoscopic repair
Authors: McNally T. P. , Rodgerson D. H. , Lu K. G.
Published: September 2011

Uterine rupture is a well recognised and potentially fatal complication in theperipartumbroodmare. This case report describes a 16 month history of infertility as the sole clinical sign in a Thoroughbred mare, subsequently diagnosed with a full thickness uterine tear. The clinical course, standing laparoscopically assisted repair and outcome are discussed.
What motivates girls to take up exercise during adolescence? Learning from those who succeed
Authors: Gillison Fiona , Sebire Simon , Standage Martyn
Published: September 2011

Objectives. The present study explored factors that underpin increased internalization (i.e., perceived autonomy) in motivation towards exercise over a 1‐year period in adolescent girls.

Design. A mixed methods prospective study.

Methods. A total of 107 girls (mean age = 13.28 years) reported their exercise behaviour, exercise goals, and a multidimensional measure of motivation towards exercise on two occasions, 1 year apart. Ten girls reporting increased autonomous motivation were then interviewed.

Results. Two themes were extracted; growing up and seeking challenge. Most participants reported being more interested in exercising for their health as a result of growing up, through having greater understanding of the health‐behaviour link and willingness to act now for future health gain. However, their motivation appeared to be only partially internalized, as health was still viewed primarily as a value promoted by respected others (parents, teachers, media). Furthermore, as many girls conflated being healthy with being thin, health for appearance‐related weight control was experienced as an extrinsic (controlling) goal. The second theme was more suggestive of autonomous motivation; girls reported valuing exercise for the opportunity it provides to set and achieve personally meaningful challenges, facilitating a sense of competence and achievement.

Conclusions. The findings may have a useful application in suggesting how exercise settings could be manipulated to increase enjoyment and participation during adolescence. In particular, the findings suggest that means of increasing the salience of the rewarding nature of setting and reaching personal challenges in an exercise setting are investigated.
Expressions of dissatisfaction and complaint by people with learning disabilities: A discourse analytic study
Authors: Jingree Treena , Finlay W.M.L.
Published: September 2011

This paper uses critical discursive psychology to examine expressions of dissatisfaction and complaint by people with learning disabilities. UK government policies stress that people with learning disabilities should have more control over their lives. Expressing dissatisfaction about services is an important aspect of this process. However, given that such individuals are often treated as incompetent, and given the delicate nature of complaining about services one might rely on for day‐to‐day support, this can be difficult to do. In building complaints, speakers drew on repertoires about competence and incompetence, the right to free choice as a principle, and tempered dissatisfaction to make contrasts between good and bad supporters and practice. While the complaints show many of the general features of complaints identified in previous work in the general population, they were crafted to the particular institutional context of social care, and attended both explicitly and implicitly to the particular issues of competence, power, and authority found in those services. Speakers positioned themselves as competent, and service workers as more or less competent in their roles. Issues of power in social care services were observed explicitly in the accounts, whereby people described staff as controlling and it being difficult to voice dissatisfaction. They were also implicit in the way speakers drew on the others with institutional authority for corroboration and comparison.
Explaining the harmonic sequence paradox
Authors: Schmidt Ulrich , Zimper Alexander
Published: September 2011

According to the harmonic sequence paradox, an expected utility decision maker’s willingness to pay for a gamble whose expected payoffs evolve according to the harmonic series is finite if and only if his marginal utility of additional income becomes zero for rather low payoff levels. Since the assumption of zero marginal utility is implausible for finite payoff levels, expected utility theory – as well as its standard generalizations such as cumulative prospect theory – are apparently unable to explain a finite willingness to pay. This paper presents first an experimental study of the harmonic sequence paradox. Additionally, it demonstrates that the theoretical argument of the harmonic sequence paradox only applies to time‐patient decision makers, whereas the paradox is easily avoided if time‐impatience is introduced.
Cluster algebras via cluster categories with infinite-dimensional morphism spaces
Authors: Plamondon Pierre-Guy
Published: September 2011

We apply our previous work on cluster characters for Hom-infinite cluster categories to the theory of cluster algebras. We give a new proof of Conjectures 5.4, 6.13, 7.2, 7.10 and 7.12 of Fomin and Zelevinsky’s Cluster algebras IV [Compositio Math. 143 (2007), 112–164] for skew-symmetric cluster algebras. We also construct an explicit bijection sending certain objects of the cluster category to the decorated representations of Derksen, Weyman and Zelevinsky, and show that it is compatible with mutations in both settings. Using this map, we give a categorical interpretation of the E-invariant and show that an arbitrary decorated representation with vanishing E-invariant is characterized by its g-vector. Finally, we obtain a substitution formula for cluster characters of not necessarily rigid objects.
Utilization of Li-Ion Battery Assisted Fuel Cell System in Warships
Authors: Turhan Mahmut , Abut Nurettin
Published: September 2011

In this study, design principles required for fuel cells to be used in systems that need inrush current are disclosed. The most important difference that separates this study from others is the consideration of utilizing Li-ion batteries to provide power where inrush current is needed in order to spread. In previous studies, lead acid batteries were used instead of Li-ion batteries. Noiselessness and effective electric production ability make fuel cells a good alternative for military applications. The Li-ion battery is the state of the art technology and while advantages include their light weight and the facts that they occupy less space, charge quickly, and have high power intensity, one can experience problems charging because of their charge characteristics. The desired voltage and current can be obtained through serial and parallel implementation of Li-ion batteries. Li-ion batteries and fuel cells are the technology of our day and it is desirable to obtain a more effective system by bringing the advantages of both to the same system. A high efficiency and silent energy is obtained through the use of fuel cells, and Li-ion batteries will enable their use in systems requiring inrush current. Noiseless maneuvering capability in the operational area for a battle ship is a very important factor to preserve. In this study, a way in which these two technologies can be used in cooperation and in an efficient way is described. Fuel cells that have output power 1000 W, output voltage 115 V, and output frequency 60 Hz were tested in the radio room of a corvette of the Turkish Navy.
Effect of Dy3+ on the Microstructure and Electrical Properties of Ce0.8Sm0.2−xDyxO1.9 (0 ≤ x ≤ 0.15) Electrolytes for IT-SOFC
Authors: Park K. , Hwang H. K.
Published: September 2011

High-quality nanosized Ce0.8Sm0.2-xDyxO1.9 (0 ≤ x ≤ 0.15) powders were successfully synthesized by solution combustion method. Calcined Ce0.8Sm0.2−xDyxO1.9 (0 ≤ x ≤ 0.15) powders and sintered Ce0.8Sm0.2−xDyxO1.9 (0 ≤ x ≤ 0.15) pellets crystallized in the cubic fluorite structure. Dense and nanocrystalline Ce0.8Sm0.2−xDyxO1.9 electrolytes were fabricated, even at low sintering temperature (1300 °C). The microstructure and electrical property of the Ce0.8Sm0.2−xDyxO1.9 were discussed, depending on the Dy3+ content. The highest conductivity (0.053 S cm−1 at 800 °C) was obtained for Ce0.8Sm0.17Dy0.03O1.9.
Parallel Manifold Effects on the Heat and Mass Transfer Characteristics of Metal-Supported Solid Oxide Fuel Cell Stacks
Authors: Park Joonguen , Bae Joongmyeon
Published: September 2011

The metal-supported solid oxide fuel cell (SOFC) was introduced as a new fuel cell design because it provides high mechanical strength and blocks gas leakage. Ordinary SOFCs should be manufactured in a stack because a single cell does not have sufficient capacity for a commercial system. In a stack, heat and mass transfer, which affects the performance, is altered by manifold structures. Therefore, this paper studied three kinds of manifold designs using numerical analyses. Governing equations and electrochemical reaction models were calculated simultaneously to conduct multiphysics simulations. Molecular diffusion and Knudsen diffusion were considered together to predict gas diffusion in a porous medium. Simulation results were compared with experimental data to validate the numerical code. There was a high current density with a high partial pressure of reactant gas on the hydrogen inlet and at the point where the hydrogen channel and the air channel intersected. The average current density of a cross-co flow design was 4890.5 A/m2, which was higher than the other designs used in this study. The average current densities of the cross-counter flow design and the cross flow design were 4689.1 and 4111.8 A/m2, respectively. The maximum pressure was 750 Pa in the air manifold and 32 Pa in the hydrogen manifold. The temperature of the bottom cell was lower than the top cell because the bottom cell had little exothermic heat by low polarization.
Fabrication of Ba(Ce, Zr)0.9Y0.1O3-α Thin Film on a Dense Pd Substrate by Ultraviolet Metalorganic Deposition
Authors: Asano K. , Kozawa Y. , Mugikura Y. , Watanabe T.
Published: September 2011

The formation of dense thin films to obtain an intermediate temperature solid oxide fuel cell (IT-SOFC) that uses Ba(Ce1−xZrx)0.9Y0.1O3−α (BCZYO, x = 0, 0.3, 1) as the proton conductor was attempted on a dense Pd substrate at low sintering temperatures by the metalorganic deposition (MOD) method. A BaCe0.9Y0.1O3−α (BCYO) thin film (thickness 0.8 μm) was prepared by MOD and then annealed at 850°C on a Pd substrate with low heat resistance. However, there are problems such as the very low density of the BCYO film and the presence of a PdO interlayer between the film and the Pd substrate. The densification of the crystallized BCYO thin film, which is about 0.5-μm thick, was improved by introducing a UV-assisted MOD process. Rapid thermal annealing (RTA) eliminated the PdO interlayer. In addition, the formation of dense thin films of BCZYO was achieved by the same UV-MOD (RTA) method. Therefore, the successful application of UV-MOD (RTA) to the formation of BCZYO thin films at low sintering temperatures was established.
Identification of Regional Mechanical Anisotropy in Soft Tissue Analogs
Authors: Raghupathy Ramesh , Witzenburg Colleen , Lake Spencer P. , Sander Edward A. , Barocas Victor H.
Published: September 2011

In a previous work (Raghupathy and Barocas, 2010, “Generalized Anisotropic Inverse Mechanics for Soft Tissues,”J. Biomech. Eng., 132(8), pp. 081006), a generalized anisotropic inverse mechanics method applicable to soft tissues was presented and tested against simulated data. Here we demonstrate the ability of the method to identify regional differences in anisotropy from full-field displacements and boundary forces obtained from biaxial extension tests on soft tissue analogs. Tissue heterogeneity was evaluated by partitioning the domain into homogeneous subdomains. Tests on elastomer samples demonstrated the performance of the method on isotropic materials with uniform and nonuniform properties. Tests on fibroblast-remodeled collagen cruciforms indicated a strong correlation between local structural anisotropy (measured by polarized light microscopy) and the evaluated local mechanical anisotropy. The results demonstrate the potential to quantify regional anisotropic material behavior on an intact tissue sample.
MRI-Based Modeling for Radiocarpal Joint Mechanics: Validation Criteria and Results for Four Specimen-Specific Models
Authors: Fischer Kenneth J. , Johnson Joshua E. , Waller Alexander J. , McIff Terence E. , Bruce Toby E. , Bilgen Mehmet
Published: September 2011

The objective of this study was to validate the MRI-based joint contact modeling methodology in the radiocarpal joints by comparison of model results with invasive specimen-specific radiocarpal contact measurements from four cadaver experiments. We used a single validation criterion for multiple outcome measures to characterize the utility and overall validity of the modeling approach. For each experiment, a Pressurex film and a Tekscan sensor were sequentially placed into the radiocarpal joints during simulated grasp. Computer models were constructed based on MRI visualization of the cadaver specimens without load. Images were also acquired during the loaded configuration used with the direct experimental measurements. Geometric surface models of the radius, scaphoid and lunate (including cartilage) were constructed from the images acquired without the load. The carpal bone motions from the unloaded state to the loaded state were determined using a series of 3D image registrations. Cartilage thickness was assumed uniform at 1.0 mm with an effective compressive modulus of 4 MPa. Validation was based on experimental versus model contact area, contact force, average contact pressure and peak contact pressure for the radioscaphoid and radiolunate articulations. Contact area was also measured directly from images acquired under load and compared to the experimental and model data. Qualitatively, there was good correspondence between the MRI-based model data and experimental data, with consistent relative size, shape and location of radioscaphoid and radiolunate contact regions. Quantitative data from the model generally compared well with the experimental data for all specimens. Contact area from the MRI-based model was very similar to the contact area measured directly from the images. For all outcome measures except average and peak pressures, at least two specimen models met the validation criteria with respect to experimental measurements for both articulations. Only the model for one specimen met the validation criteria for average and peak pressure of both articulations; however the experimental measures for peak pressure also exhibited high variability. MRI-based modeling can reliably be used for evaluating the contact area and contact force with similar confidence as in currently available experimental techniques. Average contact pressure, and peak contact pressure were more variable from all measurement techniques, and these measures from MRI-based modeling should be used with some caution.
Akt Determines Cell Fate Through Inhibition of the PERK-eIF2α Phosphorylation Pathway
Authors: Mounir Zineb , Krishnamoorthy Jothi Latha , Wang Shuo , Papadopoulou Barbara , Campbell Shirley , Muller William J. , Hatzoglou Maria , Koromilas Antonis E.
Published: September 2011

Inhibition of a stress-response pathway renders tumor cells more susceptible to death induced by inhibitors of phosphoinositide 3-kinase signaling.
Bistability in Biochemical Signaling Models
Authors: Sobie Eric A.
Published: September 2011

Lecture notes, slides, and homework assignments illustrate a strategy for teaching mathematical treatments of biological bistability.
GRK5 Goes Neuronal
Authors: Thompson Heather M.
Published: September 2011

GRK5 promotes neurogenesis in a kinase-independent manner by linking actin bundles to the cell membrane.
Reversible Cardiac Conduction Block and Defibrillation with High-Frequency Electric Field
Authors: Tandri Harikrishna , Weinberg Seth H. , Chang Kelly C. , Zhu Renjun , Trayanova Natalia A. , Tung Leslie , Berger Ronald D.
Published: September 2011

High-frequency electric fields partially depolarize myocardial cells, inducing a reversible refractory state that terminates reentrant arrhythmias.
Computationally Generated Cardiac Biomarkers for Risk Stratification After Acute Coronary Syndrome
Authors: Syed Zeeshan , Stultz Collin M. , Scirica Benjamin M. , Guttag John V.
Published: September 2011

Computational biomarkers extracted by machine learning from electrocardiograms improve identification of high-risk patients after coronary events.
Translating Glutamate: From Pathophysiology to Treatment
Authors: Javitt Daniel C. , Schoepp Darryle , Kalivas Peter W. , Volkow Nora D. , Zarate Carlos , Merchant Kalpana , Bear Mark F. , Umbricht Daniel , Hajos Mihaly , Potter William Z. , Lee Chi-Ming
Published: September 2011

On 21 to 22 June 2010, the Institute of Medicine Forum on Neuroscience and Nervous System Disorders, Board on Health Sciences Policy, discussed the role of glutamate in neuropsychiatric disease at the meeting “Glutamate-Related Biomarkers in Drug Development for Disorders of the Nervous System.”
Creating the Future Biomedical Research Workforce
Authors: Meyers Frederick J. , Pomeroy Claire
Published: September 2011

As an NIH task force ponders the future of the U.S. biomedical workforce, clinical and translational scientists can contribute crucial insights.
Teaching the Fetal Hypothalamus
Authors: Mashour George A.
Published: September 2011

Synchronization of gene expression between the placenta and fetal hypothalamus may transmit maternal responses through generations and regulate reproductive functions.
Science Translational Medicine
Podcast: 28 September 2011
Authors: Berger Ronald , Frisk Megan
Published: September 2011

A conversation with Ronald Berger about using high-frequency alternating current to stop life-threatening ventricular fibrillation.
Less is more. Possible ways to improve tuition of the recovery position
Authors: Joshi Mary Sissons , Lamb Roger
Published: September 2011

Aim

To identify what 10–11-year-old children do and do not learn during a 10 min session teaching the recovery position, with a view to suggesting possible improvements in training.

Methods

Participants were 148 boys and 144 girls. Before intervention, safety knowledge was assessed in a pencil and paper test. 198 children were taught the recovery position at a safety education centre. Three months later, their attempts to leave a casualty in a safe position were observed, and compared with the attempts of 94 children who had not received training.

Results

19% of the control group and 31% of trained children successfully placed a casualty in the recovery position. Only two of the seven standard routine moves were used by more than 50% of trained children, namely raise the casualty's leg to a flexed position, roll the casualty on to his/her side. Even when performed, these and other individual moves were often not integrated into an effective routine.

Conclusions

The implication is that in a short session it is over-ambitious to attempt to teach a complex routine. It is more realistic to focus on a few moves which are easily learnt. The present results suggest that these should be flexing the leg and rolling the casualty on to his/her side. In this study, simply improving the participants' performance of these two moves could increase the number of learners who are successful from less than a third to nearly 50%.
Iatrogenic dissection during neurointerventional procedures: a retrospective analysis
Authors: Paramasivam Srinivasan , Leesch Wolfgang , Fifi Johanna , Ortiz Rafael , Niimi Yasunari , Berenstein Alejandro
Published: September 2011

Introduction

Retrospective analysis of patients suffering iatrogenic dissection during neurointervention is reported. The circumstances surrounding the occurrence, early detection, clinical course and management options are discussed.

Methods and results

18 iatrogenic dissections over 11 years were retrospectively analyzed. Data were gathered from patient records, run sheets, morbidity records and imaging studies. All procedures were done by operators trained to operate according to institution standards. Total cases were 6981, with 3925 angiograms and 3056 interventions. Incidence was 0.26%, with 0.25% during diagnostic and 0.26% during intervention. 1031 pediatric cases had no dissections. Beyond 35 years, dissection rate increased to 0.35%. There was no difference between men and women. Carotid dissection was more common than vertebral. Most were minimal intimal tear (67%) and others flow limiting (33%). All cases were managed with heparin in the acute stage and later with aspirin and Plavix or Coumadin, except in two cases. Cases having >70% luminal narrowing with poor intracranial cross circulation were stented. None presented with neurologic deficits acutely or on follow-up. 94% of patients were followed for a variable period, with variable imaging modalities, being a retrospective study. Angiogram, MRI brain with MR angiography (MRA), Doppler ultrasonogram and CT angiograms were used for follow-up. There was good outcome in 94% of the followed-up cases.

Conclusion

Iatrogenic dissection is a random event with a benign clinical course. Early detection and aggressive management result in excellent outcome. Angiography is the best modality to follow-up. Non-invasive imaging like MRI with MRA and duplex ultrasonography are good tools to follow dissections.
Delayed intraparenchymal hemorrhage following pipeline embolization device treatment for a giant recanalized ophthalmic aneurysm
Authors: Velat Gregory J , Fargen Kyle M , Lawson Matthew F , Hoh Brian L , Fiorella David , Mocco J
Published: September 2011

The pipeline embolization device has demonstrated clinical success in the management of complex intracranial aneurysms arising along the anterior intracranial circulation with a relatively low complication profile. A case report is presented which describes a novel complication of delayed intraparenchymal hemorrhage following deployment of a pipeline embolization device for the treatment of a previously ruptured partially thrombosed ophthalmic segment aneurysm.
Hydrogen peroxide decomposition in bicarbonate solution catalyzed by divalent manganese species*This article has a companion paper in this issue (doi: 10.1139/v11-078).
Authors: Attiogbe Francis K. , Francis Raymond C.
Published: September 2011

The peroxymonocarbonate mono- and di-anions (HCO4– and CO42–) are known to be generated from H2O2/HCO3–. They are promising oxidants for wood pulp bleaching, but peroxide decomposition catalyzed by Mn(II) species may be significant for pulp samples with unusually high Mn contents. This investigation aimed to see if HCO3– addition caused destabilization of the peroxygen system owing to its partial conversion to HCO4–. This anionic peracid is a much stronger oxidant than H2O2 and could lead to a higher rate of Mn(II) oxidation to Mn(III) and (or) Mn(IV). For most free radical chain mechanisms, an increase in Mn(II) oxidation results in a higher rate of peroxide decomposition. Peroxide decomposition catalyzed by Mn(II) was investigated in H2O2/HCO3 in the pH ranges 8.5–8.7 and 7.4–7.9. The rate equation for peroxide decomposition was first order in [H2O2] and [Mn(II)] in both pH ranges, but close to second order in [HCO3–] in the higher pH range and close to third order in the lower pH range. Free radical chain mechanisms were proposed for both pH ranges and with all the correct reaction orders. Contrary to mechanisms previously proposed, it was concluded that HCO4– is the principal oxidizer of Mn(II) in the pH 7.4–7.9 range.
A theoretical study of bipolar organic transport material: Disilanyl double-pillared bisanthracene (SiDPBA)
Authors: Yang Gui-Xia , Fan Hai-Lin , Niu Xiao-Di , Huang Zong-Hao
Published: September 2011

A novel anthracene derivative, disilanyl double-pillared bisanthracene (SiDPBA), has been recently synthesized, which effectively functions as a bipolar carrier transport material in OLEDs. Its charge transport properties have been systemically investigated by band model and hopping model. Band structure calculations of SiDPBA show that the dispersions of the larger valence band and conduction band are comparable, which demonstrates that both electron and hole are favoured for transport, and that SiDPBA has the potential to be used as bipolar transport material from the viewpoint of band model. The density of states and transfer integrals in the main pathways show that it is the edge-to-face CH···π interaction that determines the charge transport property, and that the SiMe2 group contibutes little to it. The calculated charge mobilities of holes and electrons are 0.461 and 0.116 cm2·V–1·s–1, respectively. They are the same order of magnitude, and the electron mobility is on the order of magnitude of perylene-3,4:9,10-tetracarboxylic acid bisimide (PBI) derivatives (0.34 cm2·V–1·s–1). Both models demonstrate that ·SiDPBA has the potential to be used as a bipolar transport material.