bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Trait Loci × Maternal Cytoplasmic Environment Interaction for Development Rate in Oncorhynchus mykiss
Authors: Nichols Krista M , Broman Karl W , Sundin Kyle , Young Jennifer M , Wheeler Paul A , Thorgaard Gary H
Published: October 2006

Effects of maternal cytoplasmic environment (MCE) on development rate in rainbow trout were evaluated within a quantitative trait loci (QTL) analysis framework. Previous research had identified QTL for development rate in doubled haploid (DH) progeny produced from a cross between the Oregon State University (OSU) and the Swanson (SW) River rainbow trout clonal lines. In this study, progeny for QTL mapping were produced from a cross between the OSU and Clearwater (CW) River clonal lines. Doubled haploids were produced from the OSU × CW F1 by androgenesis using eggs from different females (or MCEs); with androgenesis, the maternal nuclear genome was destroyed by irradiation and diploidy was restored by blocking the first embryonic cleavage by heat shock. All embryos were incubated at the same temperature and development rate quantified as time to hatch. Using a linkage map constructed primarily with AFLP markers, QTL mapping was performed, including MCE covariates and QTL × MCE effects in models for testing. The major QTL for development rate in the OSU×SW cross overlaps with the major QTL found in this OSU × CW cross; effects at this locus were the same across MCEs. Both MCE and QTL × MCE effects contribute to variability in development rate, but QTL × MCE were minor and detected only at small-effect QTL.
A Specific Subset of Transient Receptor Potential Vanilloid-Type Channel Subunits inCaenorhabditis elegansEndocrine Cells Function as Mixed Heteromers to Promote Neurotransmitter Release
Authors: Jose Antony M , Bany I Amy , Chase Daniel L , Koelle Michael R
Published: October 2006

Transient receptor potential (TRP) channel subunits form homotetramers that function in sensory transduction. Heteromeric channels also form, but their physiological subunit compositions and functions are largely unknown. We found a dominant-negative mutant of the C. elegans TRPV (vanilloid-type) subunit OCR-2 that apparently incorporates into and inactivates OCR-2 homomers as well as heteromers with the TRPV subunits OCR-1 and -4, resulting in a premature egg-laying defect. This defect is reproduced by knocking out all three OCR genes, but not by any single knockout. Thus a mixture of redundant heteromeric channels prevents premature egg laying. These channels, as well as the G-protein Gαo, function in neuroendocrine cells to promote release of neurotransmitters that block egg laying until eggs filling the uterus deform the neuroendocrine cells. The TRPV channel OSM-9, previously suggested to be an obligate heteromeric partner of OCR-2 in sensory neurons, is expressed in the neuroendocrine cells but has no detectable role in egg laying. Our results identify a specific set of heteromeric TRPV channels that redundantly regulate neuroendocrine function and show that a subunit combination that functions in sensory neurons is also present in neuroendocrine cells but has no detectable function in these cells.
Comparison of Upper Thermal Tolerances of Native and Nonnative Fish Species in Arizona
Authors: Carveth Corissa J. , Widmer Ann M. , Bonar Scott A.
Published: October 2006

We used a lethal thermal method to estimate the upper thermal tolerances of 11 native and 7 nonnative fish species found throughout southern Arizona. Fish were acclimated to 25°C and 30°C. For all species tested, an increase in acclimation temperature resulted in a higher thermal tolerance value. Among the species acclimated to 25°C, desert pupfish Cyprinodon macularius, western mosquitofish Gambusia affinis, and Gila topminnow Poeciliopsis occidentalis were most tolerant to high temperature. Speckled dace Rhinichthys osculus, spikedace Meda fulgida, and loach minnow R. cobitis were least tolerant. Many native species demonstrated a limited ability to extend their upper temperature tolerances via acclimation. Our data suggest that several native species may be sensitive to increasing annual and large daily temperature fluctuations in Arizona's streams and rivers. Although southwestern native fishes were previously believed to be tolerant to high temperature due to their evolution in desert environments, this study suggests that many of these fishes are less tolerant than previously thought. In addition, many fishes introduced from the eastern United States had higher temperature tolerances than some of the native desert species tested. Increases in stream temperatures in Arizona could reduce the habitat available for native fishes and therefore may favor those nonnative species with higher thermal tolerances.
THE EFFECTS OF PERCEIVED RISK ON THE WORD-OF-MOUTH COMMUNICATION DYAD
Authors: Lin Tom M. Y. , Fang Cheng-Hsi
Published: October 2006

This study examined the effects of perceived risk on the sender and the receiver of word-of-mouth (WOM) communication. Regression analysis of 675 questionnaires administered in Taiwan metropolitan areas confirmed that financial risk and performance risk have significant positive effects
on WOM's influencing of the receiver's purchase decision, whereas social risk and psychological risk have significant positive effects on the sender's intention of WOM spread. Product familiarity was identified as a moderator of the relationship between expected performance
risk and WOM spread. There was a negative relationship between expected performance risk and WOM spread when people were unfamiliar with the product.
EFFECTS OF PERCEIVED SELECTION RATIO ON PERSONALITY TEST FAKING
Authors: Robie Chet
Published: October 2006

Research has not investigated the degree to which perceived selection ratio may affect faking on personality inventories. In this study, two personality inventories that differed in item subtlety were administered to 150 undergraduate students. Half of the students were administered
a personality inventory with more obvious items (n = 75) and half of the students were administered a personality inventory with more subtle items (n = 75). For each personality inventory, 25 students were randomly assigned to each of the following experimental conditions which
included financial incentives to mirror the real-world motivational processes underlying desire for the job: (1) low perceived selection ratio; (2) moderate perceived selection ratio; and (3) high perceived selection ratio. Results showed no statistically significant mean differences between
personality scale scores across levels of perceived selection ratios for each personality inventory.
TESTING COMPETING FACTOR MODELS UNDERLYING THE PRIVATE SELF-CONSCIOUSNESS SCALE WITH HONG KONG CHINESE ADOLESCENTS
Authors: Wu Joseph Keung Fai , Watkins David
Published: October 2006

This study evaluated competing factor models underlying the Private Self-Consciousness scale (Fenigstein, Scheier, & Buss, 1975) with a large sample of Hong Kong Chinese adolescents. Reliability analysis and exploratory and confirmatory factor analysis did not lend empirical support
to the three split-factor models proposed in previous research (Anderson, Bohon, & Berrigan, 1996; Burnkrant & Page, 1984; Martin & Debus, 1999). It was recommended that the original unitary model proposed by Fenigstein et al. should be retained in interpreting scores made on this
scale, at least for Hong Kong Chinese adolescents. Possible influences of age and culture on the factor structure of the scale were also discussed.
MORAL REASONING: THE INFLUENCE OF AFFECTIVE PERSONALITY, DILEMMA CONTENT AND GENDER
Authors: Agerström Jens , Möller Kristiina , Archer Trevor
Published: October 2006

This study examined the influence of affective personality, perfectionism, gender, arousal and dilemma content on moral reasoning. 264 participants were presented with moral dilemmas to which they had to provide a solution that reflected various degrees of justice and care. The results
indicated that a) affective personality had an effect on moral reasoning, b) female participants reported higher levels of care morality than did male participants, c) gender interacted with perfectionism in the production of moral standpoints, d) dilemma content exerted a strong effect on
the participants' use of moral strategy. It was concluded that although moral reasoning appears to be governed primarily by the dilemma content at hand, an individual's moral solutions are influenced by gender and affective state.
YOUNG CHILDREN'S DISPLAY RULE KNOWLEDGE: UNDERSTANDING THE DISTINCTION BETWEEN APPARENT AND REAL EMOTIONS AND THE MOTIVES UNDERLYING THE USE OF DISPLAY RULES
Authors: Misailidi Plousia
Published: October 2006

Aspects of 72 preschoolers' display rule knowledge – the ability to distinguish apparent from real emotions and understand the motives underlying display rule use – were examined. Children listened to stories describing situations designed to elicit an emotion in the
protagonist and a prosocial or self-protective reason for concealing her/his real emotion from other story characters. Children were asked to predict what facial expressions the protagonists would display in response to the emotionally laden situations and to justify their predictions.
Findings revealed that children's ability to distinguish between apparent and real emotions increased in the 4–6 years age span. Moreover, children justified prosocial and self-protective display rules with similar accuracy. The findings are discussed in terms of children's
ability to make the appearance-reality distinction across domains (emotional, physical) and in the context of the socialization of emotional displays.
Borderline ovarian tumors
Authors: Mastilovic Katarina , Ivkovic-Kapicl Tatjana , Zivaljevic Milica , Rajovic Jelka , Nincic Dejan
Published: October 2006

Borderline ovarian tumors are classified between benign cystadenoma and malignant cystadenocarcinoma. They are characterized as malignant tumors by histopathological features, which make them different from the benign ones. These tumors are commonly diagnosed at the early disease stage. The treatment of these tumors is surgical. The prognosis depends on the stage of disease and histopahtological types. We present 10 patients operated at the Institute of Oncology Sremska Kamenica because of malignant tumors with low malignant oncogenic potential in the period between 2000 and 2005. All patients had surgical treatment with ex tempore diagnostics, hysterectomy and adnexectomy with total omentectomy, or unilaterals adnexectomy. All patients had negative cytoanalytic findings of the small pelvis. Histopathological findings are necessary to confirm the diagnosis of disease. In young patients who had no children fertility can be preserved.
Chronic hepatitis C virus infection: Is there a correlation between HCV genotypes and the level of viremia?
Authors: Delic Dragan , Nesic Zorica , Simonovic Jasmina , Svirtlih Neda , Dokic Ljubisa , Neskovic Gorana
Published: October 2006

Introduction. Hepatitis C virus (HCV) RNA status and HCV genotypes have become extremely important for exact diagnosis, prognosis, duration of treatment and monitoring of antiviral therapy of chronic HCV infection. Material and methods. For the purpose of precise and objective assessment of virologic analyses, such as the determination of the number of virus copies and virus genotypes, 110 patients with chronic HCV infection were tested. Genotyping of HCV isolates and HCV RNA quantification were performed by using the PCR method. Genotype lb infection was verified in 49.1% of patients, genotype 3a infection was found in 28.2%, genotype 4 in 9.1%, genotype 2 in 4.5%, while mixed genotype infections were diagnosed in 9.1% of cases. Results. Patients infected by genotype lb had significantly higher serum HCV RNA level in relation to patients infected by other genotypes (p<0.05). Over 70% of patients infected by genotype lb had more than 2xl06 virus copies in 1 ml of blood, while in genotypes 2, 3a and 4, the percentage was 40%, 38.5% and 30%, respectively. Male patients had approximately 7.7x10.6 virus copies in 1 ml of blood, which was significantly higher in comparison with female patients (2.3xl06 copies/ml; p<0.05). Conclusion. Our results are in concordance with the results of other authors reporting that genotype lb is predominant in Europe, as well as significantly higher incidence of viremia in patients with genotype lb infection in relation to other HCV genotypes. Based on these results, we can conclude that our patients, most commonly, present with severe clinical course of chronic HCV infection and require longer treatment (48 weeks), which causes economic problems. .
Antibiotic prescribing policy of the Republic health insurance fund of Montenegro in the period 2000-2004: Effects of drug utilization reform strategy
Authors: Duborija-Kovacevic Natasa
Published: October 2006

Introduction. Monitoring of antibiotic prescribing promotes rational use of these drugs, reduces costs and slows down the progress of resistance. The objective of present study was to analyze the effects of drug utilization reform strategy realized by the Republic Health Insurance Fund of Montenegro, during the period 2000-2004. Material and methods. This before-after comparative pharmacoepidemiological study comprised a sample of 100% prescription only antibiotics available in public pharmacies during the period 2000-2004. The drug use was calculated using A TC/DDD methodology and Wilcoxon's test for matched pairs was used in order to calculate the statistical significance of difference. Results. Antibiotic prescribing was aproximately lower by 12% in 2004 in regard to 2000 (12.80 vs. 14.57 DDDs, p>0.05). The participation of this pharmacotherapeutic group in the total drug dispensing has remained almost equal (aproximately 8%). The highest increase in prescribing was established for macrolides (1.05 vs. 1.64 DDDs, 59%); penicillins were also prescribed more frequently (6.41 vs. 6.56 DDDs, 2%). but other subgroups were prescribed less frequently: cephalosporins - (23%) (3.11 vs. 2.43 DDDs) and quinolones - (63%) f 1.10 vs. 0.47 DDDs). Conclusion The drug utilization reform strategy showed mostly positive effects on antibiotic prescribing during the period 2000-2004. Further educational activities are necessary in order to establish more rational approach to prescribing and utilization of antibiotics. .
Natriuretic peptides and multimarker approach to risk stratification of patients with acute coronary syndromes
Authors: Matunovic Radomir , Stojanovic Aleksandar , Mijailovic Zdravko , Cosic Zoran
Published: October 2006

Natriuretic peptides in acute coronary syndromes Brain natriuretic peptides (BNP) and N-terminal prohormone brain natriuretic peptides (N-proBNP) have been shown to provide important prognostic information in patients with acute coronary syndrome (ACS). Ischemia may be an important stimulus for BNP release. This does not imply, however, that BNP is useful for diagnosing ischemia, and BNP is unlikely to prove sensitive or specific enough for this purpose. Significance of natriuretic peptides in assessing prognosis in patients with acute coronary syndromes In patients with ST-elevation and non-ST-elevation myocardial infarction, higher BNP and N-proBNP levels have been shown to predict a grater likelihood of death or heart faiulure, independent of other prognostic factors. Therapeutic implications of BNP elevation in acute coronary syndromes Patients with BNP or NT-proBNP elevation following ACS are clearly at high risk for death and for developement of heart failure, but specific therapeutic implications of BNP elevation have not been defined. In particular, it is not known how patients with BNP elevation should be treated considering the fact that they have normal troponin levels and no clinical evidence of heart failure. Multimarker strategies for risk stratification in acute coronary syndromes It has been shown recently that in patients with acute coronary syndromes the risk increased sequentially among those with one, two or three elevated biomarkers. Therapeutic applications of cardiac biomarkers in acute coronary syndromes Multimarker strategies, that incorporate panels of cardiac bio?markers, are likely to be used in the future for risk stratification and for pathophysiologically-guided treatement of patients with ACS.
Some psychological characteristics of children and adolescents with vitiligo: Our results
Authors: Prcic Sonja , Djurovic Dusanka , Djuran Verica , Vukovic Dusan , Gajinov Zorica
Published: October 2006

Introduction. Numerous studies have characterized patients with chronic skin disease as psychologically vulnerable, mainly due to the fact that their condition affects their social relations and all other aspects of life. The purpose of this work was to determine whether there are significant differences in the level of anxiety, severity of depressive symptoms, and presence of stressful life events between adolescent patients with vitiligo and healthy peers. Material and methods. 33 patients with vitiligo aged 10-15 years, and a control group of 60 healthy subjects of the same age, were included in this prospective study. A clinical examination was performed to determine the clinical types of vitiligo, estimate depressive symptoms using the Birleson Depression Scale, and anxiety was evaluated by the Spielberger's scale (State-Trait Anxiety Inventory). For determination of the frequency of stressful events, the Risk Scale was used. Results. Adolescents with vitiligo did not show more pronounced signs of anxiety or depression than healthy subjects; differences were not apparent in the Risk Scale either, considering stressful events. Discussion and conclusion. The lack of differences between the two examined groups might be due to prepubertal age of the majority of subjects. 63.63% of all children included in this study were in the prepubertal age (10-12 years), which is the period when they are still not focused on their own body and changes to physical appearance. It is possible that early onset of vitiligo is a "protective factor", enabling the child to attain compensatory mechanisms to solve the problem of vitiligo through various interests and aspirations, which do not depend on physical appearance. .
Treatment of knee flexion contracture in patients with chronic juvenile arthritis: A case report
Authors: Matijevic Radmila , Stankovic Milan , Ninkovic Srdjan , Savic Dragan , Milankov Miroslav
Published: October 2006

Introduction. Knee flexion contractures are common after-effects of juvenile arthritis. Treatment is usually conservative and may include physical therapy and kinesitherapy. Surgical treatment, particularly of the soft parts, indicated for contractures resistant to conservative treatment, helps to correct the deformity, maintain movements, and relieves pain. Intensive postoperative physiotherapy is of special importance. Case report. A 23-year-old female patient with chronic juvenile arthritis since the age of one was admitted for treatment of flexion con?tractures in both knees, muscle hypotrophy, loss of strength and gait disability. The patient underwent arthroscopic synovectomy. The operation was first performed on the right and after 3 mouths on the left knee. The pre operative range of motion in the rigth knee was 30?-70? and in the left 40?-80?. The patient underwent intensive physical therapy to reduce postoperative swelling of knees and firstly passive and then active kinesitherapy. Nine months after the first surgery and six months after the second, the range of motion in the right knee was 0?-100? and in the left 0?-105?. The strength of tested muscles was increased and gait was improved. Conclusion. Management and rehabilitation of patients with chronic juvenile arthritis include maintenance or improvement in position and function of joints that is achieved with synovectomy. The results depend on combined interdisciplinary rehabilitation, well-experienced staff, and pre- and post-operative physiotherapy as well as kinesitherapy. Arthroscopic synovectomy has many advantages and we believe that it was a better solution than open capsulosynovectomy in this patient with chronic juvenile arthritis of the knee. .
Treatment options for hypomineralized first permanent molars and incisors
Authors: Ivanovic Mirjana , Zivojinovic Vesna , Markovic Dejan , Sindolic Mirjana
Published: October 2006

The aim of this study was to discuss therapy possibilities in the management of molar incisor hypomineralization. Molar incisor hypomineralization (MIH) is defined as hypomineralization of one or more first permanent molars frequently affecting incisors. Etiology of MIH is not fully clarified and numerous etiological factors have been cited. Hypomineralized molars are more prone to caries, cause severe restorative problems and are frequently extracted due to serious damage and caries complications. Incisors can present demarcated enamel opacities, while enamel breakdown is uncommon. Clinically, affected molars can be sensitive to thermal and chemical irritations even when there is no enamel breakdown. Molars can be sensitive to mechanical irritations making even regular tooth brushing painful. Specific problems related to the treatment of these teeth are sensitivity and occlusion in molars and aesthetics in incisors. Considering the fact that permanent first molars with severe defects and incisors demand complex and multidisciplinary treatment they present serious problem for the patient as well as for the dentist.
The use of subgingival chlorhexidine chip in the treatment of periodontal disease
Authors: Lukovic Natalija , Zelic Obrad , Cakic Sasa
Published: October 2006

Due to the infective nature of periodontal disease several local devices have been used to overcome the limited efficacy of conventional periodontal treatment. However, local concentration of these medicaments, especially over time, raises the question of expediency of their use. Local delivery systems allow the therapeutic agents to be targeted to the diseased site for a long time. These systems, when retained in the periodontal pocket, can release the antimicrobial agents at levels that are 10- to 100-fold higher than the levels that can be delivered by systemic antibiotics. Several different drug delivery systems have been used in controlled clinical trials: fibers, gels and chips. The most frequently used antimicrobials are antibiotics (tetracycline, minocycline), hemotherapeutics (metronidazole), and antiseptics (chlorhexidine dicluconate). In the present paper the method of chlorhexidine chip application is analyzed. We discussed the results of studies that evaluated the efficacy of a controlled-release of biodegradable chlorhexidine chip when used as an adjust to scaling and root planning (SRP) in adult periodontitis.
Subwavelength hole arrays with nanoapertures fabricated by scanning probe nanolithography
Authors: Jaksic Z. , Maksimovic M. , Vasiljevic-Radovic D. , Sarajlic M.
Published: October 2006

Owing to their surface plasmon-based operation, arrays of subwavelength holes show extraordinary electromagnetic transmission and intense field localizations of several orders of magnitude. Thus they were proposed as the basic building blocks for a number of applications utilizing the enhancement of nonlinear optical effects. We designed and simulated nanometer-sized subwavelength holes using an analytical approach. In our experiments we used the scanning probe method for nanolithographic fabrication of subwavelength hole arrays in silver layers sputtered on a positive photoresist substrate. We fabricated ordered nanohole patterns with different shapes, dispositions and proportions. The smallest width was about 60 nm. We characterized the fabricated samples by atomic force microscopy.
Influence of the electron-phonon iinteraction on phonon heat conduction in a molecular nanowire
Authors: Galovic Slobodanka , Cevizovic D. , Zekovic S. , Ivic Z.
Published: October 2006

A model for phonon heat conduction in a molecular nanowire is developed. The calculation takes into account modification of the acoustic phonon dispersion relation due to the electron-phonon interaction. The results obtained are compared with models based upon a simpler, Callaway formula.
Electrical properties of mechanically activated zinc oxide
Authors: Vojisavljevic K. , Zunic M. , Brankovic G. , Sreckovic T.
Published: October 2006

Microstructural properties of a commercial zinc oxide powder were modified by mechanical activation in a high-energy vibro-mill. The obtained powders were dry pressed and sintered at 1100?C for 2 h. The electrical properties of grain boundaries of obtained ZnO ceramics were studied using an ac impedance analyzer. For that purpose, the ac electrical response was measured in the temperature range from 23 to 240?C in order to determine the resistance and capacitance of grain boundaries. The activation energies of conduction were obtained using an Arrhenius equation. Donor densities were calculated from Mott-Schottky measurements. The influence of microstructure, types and concentrations of defects on electrical properties was discussed.
Structure and surface composition of NiCr sputtered thin films
Authors: Petrovic S. , Bundaleski N. , Radovic M. , Ristic Z. , Gligoric G. , Perusko D. , Zec S.
Published: October 2006

Thin films of nichrome were deposited by d.c. sputtering of a target (80%Ni 20%Cr w.t) by Ar+ions at a working pressure of 10-1 Pa and at room temperature. The phase composition and grain size were studied by X-ray Diffraction (XRD), while the surface chemical composition was determined by Low Energy Ion Scattering (LEIS). Analysis of phase composition showed that the NiCr thin films were a solid solution of chromium in a nickel matrix with increased nickel lattice parameters. LEIS analysis showed the presence of Ni Cr and O in the first atomic layer. There is a strong suspicion that surface passivation occurred by forming Cr2O3 oxide at the surface.
Electrical properties of ZnO varistors prepared by direct mixing of constituent phases
Authors: Zunic M. , Brankovic Z. , Brankovic G.
Published: October 2006

Varistor samples containing different amounts of constituent phases were prepared by direct mixing of constituent phases. Detailed electrical characterization was performed to explain the influence of minor phases (spinel and intergranular phases) on overall properties. Characterization included investigation of the non-linear coefficients (?), breakdown electric field (EB), leakage currents (JL), grain boundary barrier hight (?B) and constant ? from current-voltage characteristics, as well as calculation of activation energies for conduction (EA) from ac impedance spectroscopy in the temperature interval 30-410?C. Varistors sintered at 1100 ?C for 1 h showed pronounced differences in electrical properties depending on relative molar ratios of the phases. Results were discussed in the sense of possible reduction of the content of minor phases in ZnO varistors.
Crystal field analysis of the ground and excited state absorption of a Cr4+ ion in LiAlO2 and LiGaO2 crystals
Authors: Brik Mikhail , Avram Nicolae , Avram Calin
Published: October 2006

The exchange charge model of crystal field theory has been used to analyze the ground and excited state absorption of tetrahedrally coordinated Cr4+ ion in lithium aluminum oxide LiAlO2 (γ-phase) and lithium dioxogallate LiGaO2. The parameters of the crystal field acting on the Cr4+ ion are calculated from the crystal structure data, taking into account the crystal lattice ions located at distances up to 12.744 Å in LiGaO2 and 13. 180 Å in LiAlO2. The obtained energy level schemes were compared with experimental ground and excited state absorption spectra and literature data on the application of other crystal field models (the angular overlap model and Racah theory) to the considered crystals; a good agreement with experimental data is demonstrated.
Modelling of a nitrogen x-ray laser pumped by capillary discharge
Authors: Vrba Pavel , Vrbová Miroslava , Bobrova Nadezhda , Sasorov Pavel
Published: October 2006

We performed computer modelling of a fast electrical discharge in a nitrogen-filled alumina capillary in order to discover discharge system parameters that may lead to efficient recombination pumping of soft X-ray laser with active medium created by H-like nitrogen ions. The space-time dependences of pinch plasma quantities were found by means of a one-dimensional MHD code. Time dependences of populations of all ionisation states and populations of selected energy levels of lithium-, helium- and hydrogen-like nitrogen ions were evaluated using the FLY code as a post-processor. The population inversion was found at the quantum transition corresponding to the Balmer α-line of N6+ ions and the resulting gain factor was evaluated for different capillary radii, initial pressure, electric current peaks and periods. A gain factor of 1 cm−1 spanning the time interval of 1 ns was found for an optimised arrangement with capillary radius 1.5 mm, peak current 50 kA, quarter period 40 ns and filling gas pressure 0.5 kPa. It is pointed out that even higher values of the gain factor may be achieved with thinner capillaries and shorter current pulses, e.g. a gain factor of 6 cm−1 is achieved if the capillary radius is 0.5 mm, peak current 56 kA, quarter period 15 ns, and filling nitrogen pressure 3.9 kPa.
Pre-low-mass X-ray binaries containing a black hole: investigating a detection mechanism
Authors: Bleach James
Published: October 2006

This work investigates the feasibility of detecting close, detached, black hole-red dwarf binaries, which are expected to be evolutionary precursors of low-mass X-ray binaries (LMXBs). Although this pre-low-mass X-ray binary (pre-LMXB) phase of evolution is predicted theoretically, as yet no such systems have been identified observationally. The calculations presented here suggest that the X-ray luminosity of black hole wind accretion in a pre-LMXB system could exceed the intrinsic X-ray luminosity of the red dwarf secondary star, thereby providing a detection mechanism. However, there is significant uncertainty regarding the efficiency of the conversion of gravitational potential energy to X-ray luminosity resulting from accretion onto a black hole, for example energy may be lost via advection across the event horizon. Still, sources with X-ray luminosities greater than that expected for a red dwarf star, but whose positions coincide with that of a red dwarf would represent candidate pre-LMXB systems. These candidates should be surveyed for the radial velocity shifts that would occur as a result of the orbital motion of a red dwarf star within a close binary system containing a black hole.
Using Enzymes to Control Molecular Hydrogelation
Authors: Yang Z. , Xu B.
Published: October 2006

The expression and distribution of enzymes differ by the types and states of cells, tissues, and organs, thus leading to diverse extracellular and intracellular environments. Using an enzymatic reaction to convert a precursor into a hydrogelator or vice versa, one can control the delivery, functions, and responses of a hydrogel according to a specific biological condition or environment, thus providing an accessible route to creating sophisticated soft materials for potential biomedical applications.
The battle between “good” and “better”: A strategic marketing perspective on codes of conduct for sustainable agriculture
Authors: Ingenbleek Paul , Meulenberg Matthew T.G.
Published: October 2006

Code‐of‐conduct organizations (CCOs) for sustainable agriculture, such as Fair Trade and Eurep‐Gap, are rapidly changing the face of agribusiness. Yet, there is little understanding of how these organizations contribute to sustainability. This study therefore presents a case study of the strategies by which CCOs aim to achieve their sustainability objectives. A cross‐case comparison indicates that many strategic differences between codes of conduct can be traced back to two types of CCOs: those weighting principles over size, and those weighting size over principles. The former put a measuring rule in the market, and enable primary producers to differentiate themselves from mainstream production. The latter set lower requirements, but target mainstream production and involve large retailers and processing firms. Given the unique roles played by these types of organizations, sustainable development is best served by the synergy that results under “co‐opetition”: when the two types of rival organizations coexist. [EconLit citations: L310, M310, Q560] © 2006 Wiley Periodicals, Inc. Agribusiness 22: 451–473, 2006.
The impact of cross‐sectional data aggregation on the measurement of vertical price transmission: An experiment with German food prices
Authors: von Cramon‐Taubadel Stephan , Loy Jens‐Peter , Meyer Jochen
Published: October 2006

The impact of cross‐sectional aggregation over individual retail stores on the estimation and testing of vertical price transmission between the wholesale and retail levels is investigated using a unique data set of individual retail prices in Germany. Systematic differences between the results of estimations using aggregated data on the one hand, and disaggregated data on the other, are discussed theoretically and confirmed empirically. The results suggest that estimation with aggregated data can generate misleading conclusions about price transmission behavior at the level of the individual units (i.e., retail stores) that underlie these aggregates. [JEL classifications: C22, L11, D40] © 2006 Wiley Periodicals, Inc. Agribusiness 22: 505–522, 2006.
Perspectives on the 2003 and 2004 avian influenza outbreak in Bali and Lombok
Authors: Simmons Phil
Published: October 2006

In this article, background research for potential policies to contain avian influenza (AI) in Southeast Asia is provided. The author discusses (a) factors influencing spread of AI in Indonesia, (b) ways animal health institutions in Indonesia work, (c) risk associated with AI, and (d) a possible framework for analyzing effectiveness of public and private responses to the disease. The government of Indonesia (GOI) policies and responses to the outbreak in the eastern islands' poultry industry are described. Based on interviews, Indonesian farmer responses may be affected by five factors: (1) geographical location of the farm, (2) time since the outbreak began, (3) whether the farmer was a layer, broiler, or kampung (local) chicken producer, (4) size and development of the farm, and (5) contractual arrangements under which production is occurring. A bioeconomic framework suitable for analyzing these problems is developed and presented. [EconLit citations: I180, Q130] © 2006 Wiley Periodicals, Inc. Agribusiness 22: 435–450, 2006.
Follow the leader? Adoption behavior in food retailers' decision to offer fresh irradiated ground beef
Authors: Jaenicke Edward C. , Harrison R. Wesley , Jensen Kimberly L. , Jakus Paul M.
Published: October 2006

During the 14‐month period from May 2002 through June 2003, approximately 10% of U.S. supermarkets began to offer fresh irradiated ground beef under the stores' own labels. Using a survey of supermarket store managers from this period, the authors investigate the factors that influenced stores' adoption of irradiated ground beef. Results from the adoption model show that factors associated with competition, merchandising philosophy, and structure in the food retailing industry play a strong role in the decision. Among other results, it was found that variables relating to a competitor's adoption status and proximity can increase the likelihood of a store's adoption. [EconLit citations: L660, M310, Q180] © 2006 Wiley Periodicals, Inc. Agribusiness 22: 547–568, 2006.
Designs of Superiority and Noninferiority Trials for Binary Responses are Noninterchangeable
Authors: Hilton Joan F.
Published: October 2006

To better understand the design of noninferiority trials for binary data, we identify analogies and contrasts between this and the more familiar superiority trial design. We restrict attention to the problem of detecting a difference between experimental and control response rates in the setting where there is no difference (πE – πC = 0) under the noninferiority alternative hypothesis and under the superiority null, and a matching difference between groups under the complementary hypotheses (|πE – πC | = δ). Our derivation of the constrained maximum likelihood estimates (MLEs) reveals that superiority and noninferiority trials have different nuisance parameters – the marginal response rate and the control‐group response rate, respectively. Our empirical results show that when individuals are allocated to treatment groups in the ratio that minimizes the overall sample size, balanced allocation is optimal only for superiority trials when the error rates are equal; otherwise imbalanced allocation is optimal. Different allocation ratios between trial types lead to different variances, and thus to different sample sizes. Finally, since the value of the marginal response rate – a design parameter in noninferiority trials – typically cannot be obtained from preliminary or published studies, we suggest a means of identifying a value that can be used. We conclude that full documentation of the design of a trial requires specification not only of the design parameters but also of the allocation ratio and the nuisance parameter, the value of which is not obvious under unequal allocation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Albumin is a redox‐active crowding agent that promotes oxidative folding of cysteine‐rich peptides
Authors: Buczek Olga , Green Brad R. , Bulaj Grzegorz
Published: October 2006

Oxidative folding that occurs in a crowded cellular milieu is characterized by multifaceted interactions that occur among nascent polypeptides and resident components of the endoplasmic reticulum (ER) lumen. Macromolecular crowding has been considered an essential factor in the folding of polypeptides, but the excluded volume effect has not been evaluated for small, disulfide‐rich peptides. In the research presented, we examined how macromolecular crowding agents, such as albumin, ovalbumin, and polysaccharides, influenced the kinetics and thermodynamics of forming disulfide bonds in four model peptides of varying molecular size from 13 residues (1.4 kDa) to 58‐residues (6.5 kDa): conotoxins: GI, PVIIA, r11a, and bovine pancreatic trypsin inhibitor. Our results indicate that the excluded volume effect does not significantly alter the folding rates nor equilibria for these peptides. In stark contrast, folding reactions were dramatically accelerated, when protein‐based crowding agents were present at concentrations lower than those predicted to provide the excluded volume effect. Submillimolar albumin alone was as effective as glutathione in promoting the oxidative folding of GI conotoxin at concentrations typically found in the ER. To the best of our knowledge, this is the first report and quantitative characterization of oxidative folding of peptides mediated by other than thioredoxin‐based protein disulfide bonds. Our work raises a possibility that concurrent secretory and ER‐resident proteins may influence the oxidative folding of small, cysteine‐rich peptides not as crowding agents, but as redox‐active factors. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88:8–19, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com.
Role of circulating tumour cells in predicting recurrence after excision of primary colorectal carcinoma
Authors: Allen-Mersh T G , McCullough T K , Patel H , Wharton R Q , Glover C , Jonas S K
Published: October 2006

Background

This study assessed the potential for reverse transcriptase–polymerase chain reaction (RT–PCR)-based circulating tumour cell identification to predict colorectal cancer recurrence.

Methods

mRNA for carcinoembryonic antigen and cytokeratin 20 was identified by RT–PCR in blood from patients with colorectal cancer, before and after primary tumour resection. Cancer recurrence was assessed at follow-up, and the accuracy of RT–PCR and primary tumour lymph node positivity in predicting recurrence was estimated.

Results

One hundred and ninety-six patients with colorectal cancer were studied over a median follow-up of 1393 days from surgery. Regression analysis selected 24-h post-resection RT–PCR positivity (hazard ratio for a positive test in predicting recurrence 8·66 (95 per cent confidence interval (c.i.) 3·08 to 24·33)) before lymph node involvement (hazard ratio 7·92 (95 per cent c.i. 3·26 to 19·20)). When 24-h post-resection RT–PCR was combined with lymph node positivity, the hazard ratio increased to 18·54 (95 per cent c.i. 4·01 to 85·11), attributing a 3 per cent recurrence risk to 52 per cent, and a 50 per cent recurrence risk to 48 per cent, of patients with colorectal cancer resected with curative intent.

Conclusion

RT–PCR positivity within 24 h of primary colorectal cancer resection is a strong predictor of colorectal cancer recurrence, and may be useful clinically.
Laparoscopically assisted or open enterolithotomy for gallstone ileus
Authors: Moberg A-C , Montgomery A
Published: October 2006

Background

Gallstone ileus is associated with high morbidity and mortality rates. Enterolithotomy as a single procedure is recommended to minimize complications. The trauma could potentially be reduced further by using a laparoscopic technique.

Methods

Thirty-two consecutive patients with gallstone ileus operated by a laparoscopic or open approach between 1992 and 2004 were studied retrospectively. Demographic data, preoperative and postoperative hospital stay, duration of operation, complications and deaths were recorded. Median follow-up after surgery was 36 months.

Results

Nineteen laparoscopic procedures, with two conversions, and 13 open operations were performed. The median duration of operation was 60 min in the laparoscopic group and 58 min in the open group (P = 0·675). The median hospital stay was 7 and 10 days, respectively (P = 0·383). There were five minor and one major complications in the laparoscopic group, compared with one and four, respectively, in the open group. There were no deaths within 30 days.

Conclusion

The overall morbidity rate was low after both laparoscopic and open enterolithotomy for gallstone ileus, especially in terms of major complications in the laparoscopic group. Laparoscopically assisted enterolithotomy can be recommended for both diagnosis and treatment.
Systematic reviews and meta-analysis for the surgeon scientist
Authors: Mahid S S , Hornung C A , Minor K S , Turina M , Galandiuk S
Published: October 2006

Background

Understanding of data-reporting methods is imperative for correct interpretation of the medical literature as well as for proper performance of future clinical research. Recent developments in biostatistics have greatly changed the types of statistical analyses used and the minimum quality standards that must be maintained.

Method

Different types of review are described, including systematic review with and without meta-analysis. Minimum reporting standards, sources of bias, both quantitative and qualitative, and references are discussed.

Results and Conclusion

Meta-analysis has become a clearly defined technique, with reporting standards for both randomized controlled trials and observational studies. It is assuming a wider role in the surgical literature. Although many sources of bias exist, there are clear reporting standards and readers should be aware of these when studying the literature.
Surface Properties and Catalytic Performance of La0.8K0.2CuxMn1–xO3 for Simultaneous Removal of NOx and Soot
Authors: Peng X. S. , Lin H. , Shangguan W. F. , Huang Z.
Published: October 2006

The influence of copper substitution in La0.8K0.2CuxMn1–xO3 on its catalytic performance for simultaneous removal of NOx and soot under oxygen rich conditions was investigated. A series of catalysts was prepared and then characterized by XRD, SEM, BET, and XPS. The temperature programmed reaction (TPR) method was used to evaluate the catalytic performance of the catalysts. XRD results show that the partial substitution of Cu for Mn promotes the formation of perfect perovskites. SEM and BET results demonstrate that appropriate copper substitution enhances the porosity and increases the specific surface area, leading to conditions which are favorable for heterogeneous catalysis. XPS results indicate that a fraction of the Mn3+ is converted to Mn4+ on the addition of low levels of Cu. By correlation of the physicochemical properties and the catalytic performance, a large specific surface area, high porosity, high content of Mn3+ and synergistic effects of Mn3+ and Cu2+ are seen to favor the simultaneous catalytic removal of NOx and soot.
Carbon Nanorings: A Challenge to Theoretical Chemistry
Authors: Cuesta I. García , Pedersen T. B. , Koch H. , Sánchez de Merás A.
Published: October 2006

High‐level quantum‐chemical methods show that the binding in the inclusion complex of hexamethylbenzene (HMB) in 6‐cycloparaphenilacetylene (6‐CPPA) cannot be explained only in terms of electrostatic interactions—caused by the polarization associated to curved π‐conjugated systems—and the inclusion of dispersion forces is definitely needed. The theoretical description of van der Waals interactions is notoriously complicated and in fact some DFT methods cannot even predict the existence of the relatively small supramolecular nanoring studied here. However, ab initio MP2 calculations agree with experimental data and show that, in the considered complex, the HMB fragment is placed at the center of the 6‐CPPA ring. The binding energy, which is not available experimentally, is calculated to be around −14 kcal mol−1 with a lower limit of −19 kcal mol−1.
Phosphavinylidene(oxo)phosphorane Mes*P(O)=C=PMes*: A Diphosphaallene Featuring λ5σ3‐ and λ3σ2‐Phosphorus Atoms (Eur. J. Inorg. Chem. 21/2006)
Authors: Septelean Raluca , Ranaivonjatovo Henri , Nemes Gabriela , Escudié Jean , Silaghi‐Dumitrescu Ioan , Gornitzka Heinz , Silaghi‐Dumitrescu Luminita , Massou Stéphane
Published: October 2006

The cover picture shows the P=C=P backbones of stable, neutral diphosphaallenes along with the publication year of the first example reported for given coordination numbers of the phosphorus atoms. Since the synthesis of hexaphenylcarbodiphosphorane (Ph3P=C=PPh3), a σ4,σ4‐diphosphaallene, in 1961, only two other classes of compounds with P=C=P sequences have been reported in the past decades. Details of the preparation of the phosphavinylidene(oxo)phosphorane Mes*P(O)=C=PMes* (Mes* = 2,4,6‐tri‐tert‐butylphenyl), a diphosphaallene featuring λ5σ3‐ and λ3σ2‐phosphorus atoms, NMR spectroscopic data and the first aspects of its reactivity are described in the article by H. Ranaivonjatovo, J. Escudié et al. on p. 4237 ff.