bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of liver transplantation on renal function of patients with congenital hepatic fibrosis associated with autosomal recessive polycystic kidney disease
Authors: Arikan Cigdem , Ozgenc Funda , Akman Sezin Asik , Kilic Murat , Tokat Yaman , Yagci Rasit Vural , Aydogdu Sema
Published: December 2004

Abstract:  Congenital hepatic fibrosis (CHF) is an uncommon autosomal recessive malformation. It may be associated with extrahepatic manifestations such as polycystic kidney disease. The main consequence is portal hypertension and bleeding from varices. Despite liver transplantation as a therapeutic option for this patient, long‐term impact of liver transplantation on renal functions of patients with autosomal recessive polycystic kidney disease with associated liver disease is not well known. In this study, we aimed to analyze the patient's renal function after liver transplantation by creatinine clearance, glomerular filtration rate, and renal resistive indexes. Between March 1997 and September 2002, three of 50 orthotopic liver transplantation (OLT) were performed because of CHF associated with ARPKD at Ege University Organ Transplantation and Research Center. Baseline immunosuppression consisted of prednisone and cyclosporine A (CSA). The mean follow‐up of the patients was 2.1 yr. Blood urea and creatinine levels were decreased after operation in all patients and remained within the normal range at the sixth and 12th month, whereas the level of the third patient were increased at the 18th month. RRI values of patients were not found different at the sixth month whereas, RRI values of patients were decreased at the 12th month and remained unchanged at the 18th month of follow‐up. During the study period hypertension developed in one patient at the 16th month and resolved with antihypertensive treatment and decreasing dosage of CSA. Kidney function has remained satisfactory in all of the patients despite the use of cyclosporine. OLT can provide good survival in patients with CHF associated with ARPKD.
Renal arterial resistance index and computerized quantification of fibrosis as a combined predictive tool in chronic allograft nephropathy
Authors: Pape Lars , Mengel Michael , Offner Gisela , Melter Michael , Ehrich Jochen H. H. , Strehlau Juergen
Published: December 2004

Abstract:  The renal arterial resistance index (RI) and the PicroSiriusRed stained cortical fractional interstitial fibrosis volume (VintFib) proved to be two independent methods that are reliable predictive factors of poor renal allograft outcome. No data have been published, which define the correlation between ultrasound assessment and quantitative morphologic changes. Renal biopsies were performed in 56 children according to increases in s‐creatinine >10%. VintFib was calculated by computerized image analysis. RI was determined in two segmental arteries, 1 yr after transplantation and at the time‐point of biopsy. RIs 1 yr after transplantation correlated significantly with RIs at time of biopsy (r = 0.58, p < 0.001). VintFib was higher in children with a RI = 80 than in children with a RI < 80 (mean VintFib = 9.5 ± 3.2% vs. 5.2 ± 5.1%, p = 0.004). In children with VintFib > 10%, the mean RI was 77 ± 5 compared with 69 ± 6 in patients with VintFib < 10% (p = 0.0002). The highest positive predictive value to detect the risk of decline of GFR at 2 yr after biopsy was 98% when an RI = 80% was associated with a VintFib > 10%. For VintFib > 10% or RI = 80 alone, it was 87% or 67%, respectively. The combined measurement of RI and VintFib is a reliable predictive tool for the risk of developing long‐term graft dysfunction after kidney transplantation.
Novel immunosuppressants
Authors: Krieger Nancy R. , Emre Sukru
Published: December 2004

Abstract:  Advances in maintenance immunosuppression over the past decade has resulted in dramatic improvements in short‐ and long‐term outcomes in organ transplantation as well as a decreased incidence of acute rejection. However, immunosuppressive drugs need to be given long term, lack specificity, and are accompanied by adverse metabolic derangements, toxicities, the risk of infection and cancer, and a myriad of other side effects. Further, they fail to prevent and control chronic rejection. This review will outline a number of immunosuppressive agents that are currently being explored in experimental and clinical transplantation. These include biologic agents that have more specificity and selectivity, and are aimed at T‐cell depletion, blockade of costimulation, adhesion markers, or at novel targets. Most of the studies have been limited to adults but should be applied to the pediatric population as well.
Azathioprine metabolite measurements: Its use in current clinical practice
Authors: Rumbo Carolina
Published: December 2004

Abstract:  Azathioprine (AZA) is one of the oldest immunosuppressive agents available today. It is used as an immunomodulator in different disciplines such as hematology, dermatology, rheumatology, gastroenterology, and transplant. The present article presents a summary of AZA metabolism and the role of AZA metabolite measurements in the current clinical practice.
Progressive intrahepatic cholestasis: Mechanisms, diagnosis and therapy
Authors: Shneider Benjamin L.
Published: December 2004

Abstract:  Progressive intrahepatic cholestasis (PIHC, also known as progressive familial intrahepatic cholestasis) is a general term encompassing a devastating group of illnesses manifest by severe morbidity and potential mortality. By definition these diseases are characterized by persistent cholestasis that is the result of intra‐hepatic rather than extra‐hepatic pathology. Recent scientific advances have begun to clarify the molecular basis of many of these disorders. The morbidities of these diseases are primarily the result of profound cholestasis. This cholestasis is often associated with intractable pruritus, which leads to a very poor quality of life. Normal development and sleep are not possible for the affected individual and family dynamics are sometimes irreparably damaged. The cholestasis also leads to complications of fat soluble vitamin malabsorption including osteopenia and pathologic bone fractures, xeropthalmia, and peripheral neuropathy. End‐stage liver disease and all of its attendant problems may develop in affected individuals by young adulthood. Optimal therapeutic approaches to PIHC are not well established and disease‐specific approaches may be required.
Degenerative Endometrial Changes do not Change the Functional Capacity of Immigrating Uterine Neutrophils in Mares
Authors: Zerbe H , Engelke F , Klug E , Schoon H‐A , Leibold W
Published: December 2004

Contents

An endometritis model was used to investigate the influence of degenerative endometrial changes (endometrosis) on functional parameters of uterine neutrophils in the horse. Six hours after intrauterine application of recombinant human interleukin‐8 (rhIL‐8), the uteri of 15 mares were flushed with phosphate‐buffered saline. Quantitative and qualitative flow cytometric assays were then made to determine the absolute numbers, viability, phenotype, generation of reactive oxygen species (ROS), and phagocytic activity of immigrated polymorphonuclear neutrophilic granulocytes (PMN). Recombinant hIL‐8 attracted similarly high numbers of similarly viable PMN into the uteri of mares with or without degenerative endometrial changes. Compared with blood PMN, immigrated uterine neutrophils displayed significantly upregulated expression of CD11a/CD18 (LFA‐1) on uterine PMN whereas major histocompatibility complex class I molecules were expressed at lower densities. The ability to phagocytose opsonized streptococci did not differ between uterine and blood PMN. However, uterine PMN displayed a higher capacity to generate ROS. On average, uterine PMN of mares with degenerative endometrial changes showed phenotypical and functional characteristics similar to those of mares with a histologically healthy endometrium. Therefore, degenerative endometrial changesper sedid not reduce the functional capacity of equine uterine neutrophils in mares.
Post‐traumatic stress disorder symptoms in victims of Tokyo subway attack: a 5‐year follow‐up study
Authors: OHTANI TOSHIYUKI , IWANAMI AKIRA , KASAI KIYOTO , YAMASUE HIDENORI , KATO TADAFUMI , SASAKI TSUKASA , KATO NOBUMASA
Published: December 2004

Abstract  Sarin gas was dispersed in a Tokyo subway in 1995. This study investigates the mental and somatic symptoms of the 34 victims 5 years after the attack. Structured interviews (Clinician‐Administered Post‐Traumatic Stress Disorder [CAPS] and Mini International Neuropsychiatric Interview) and self‐rating questionnaires were used to assess the symptoms. Not only post‐traumatic stress disorder (PTSD) but also non‐specific mental symptoms persisted in the victims at a high rate. A total of 11 victims were diagnosed with current or lifetime PTSD according to CAPS. Victims with PTSD showed higher anxiety levels and more visual memory impairment. A significant correlation between the total score of Impact of Event Scale‐Revised (IES‐R) and CAPS was found, indicating that IES‐R is a useful tool for evaluating PTSD.
Primary leiomyosarcoma of the vertebra: Case report and review of the literature
Authors: Sasaguri Takakazu , Tanimoto Akihide , Kimura Satoshi , Kohno Yukari , Hirasawa Motohiro , Matsuki Yasumasa , Abe Kenichi , Hashimoto Hiroshi , Hamada Tetsuo , Sasaguri Yasuyuki
Published: December 2004

A case of primary leiomyosarcoma of a thoracic vertebra associated with a compression fracture in a 75‐year‐old woman was preoperatively thought to be granulation tissue. Surgical decompression was performed and the histological and immunohistochemical studies established the diagnosis of leiomyosarcoma. Based on the clinical and radiological examinations, metastases were ruled out. Primary leiomyosarcoma of the vertebra is extremely rare and in that site it is considered to have a relatively poor prognosis.
Estimating Household Structure in Ancient China by using Historical Data: A Latent Class Analysis of Partially Missing Patterns
Authors: Liao Tim Futing
Published: December 2004

Social data often contain missing information. The problem is inevitably severe when analysing historical data. Conventionally, researchers analyse complete records only. Listwise deletion not only reduces the effective sample size but also may result in biased estimation, depending on the missingness mechanism. We analyse household types by using population registers from ancient China (618–907 AD) by comparing a simple classification, a latent class model of the complete data and a latent class model of the complete and partially missing data assuming four types of ignorable and non-ignorable missingness mechanisms. The findings show that either a frequency classification or a latent class analysis using the complete records only yielded biased estimates and incorrect conclusions in the presence of partially missing data of a non-ignorable mechanism. Although simply assuming ignorable or non-ignorable missing data produced consistently similarly higher estimates of the proportion of complex households, a specification of the relationship between the latent variable and the degree of missingness by a row effect uniform association model helped to capture the missingness mechanism better and improved the model fit.
Smooth Backfitting in Practice
Authors: Nielsen Jens Perch , Sperlich Stefan
Published: December 2004

Compared with the classical backfitting of Buja, Hastie and Tibshirani, the smooth backfitting estimator (SBE) of Mammen, Linton and Nielsen not only provides complete asymptotic theory under weaker conditions but is also more efficient, robust and easier to calculate. However, the original paper describing the SBE method is complex and the practical as well as the theoretical advantages of the method have still neither been recognized nor accepted by the statistical community. We focus on a clear presentation of the idea, the main theoretical results and practical aspects like implementation and simplification of the algorithm. We introduce a feasible cross-validation procedure and apply it to the problem of data-driven bandwidth choice for the SBE. By simulations it is shown that the SBE and our cross-validation work very well indeed. In particular, the SBE is less affected by sparseness of data in high dimensional regression problems or strongly correlated designs. The SBE has reasonable performance even in 100-dimensional additive regression problems.
Bivariate Location–Scale Models for Regression Analysis, with Applications to Lifetime Data
Authors: He Wenqing , Lawless Jerald F.
Published: December 2004

The literature on multivariate linear regression includes multivariate normal models, models that are used in survival analysis and a variety of models that are used in other areas such as econometrics. The paper considers the class of location–scale models, which includes a large proportion of the preceding models. It is shown that, for complete data, the maximum likelihood estimators for regression coefficients in a linear location–scale framework are consistent even when the joint distribution is misspecified. In addition, gains in efficiency arising from the use of a bivariate model, as opposed to separate univariate models, are studied. A major area of application for multivariate regression models is to clustered, ‘parallel’ lifetime data, so we also study the case of censored responses. Estimators of regression coefficients are no longer consistent under model misspecification, but we give simulation results that show that the bias is small in many practical situations. Gains in efficiency from bivariate models are also examined in the censored data setting. The methodology in the paper is illustrated by using lifetime data from the Diabetic Retinopathy Study.
A Jackknife Variance Estimator for Unequal Probability Sampling
Authors: Berger Yves G. , Skinner Chris J.
Published: December 2004

The jackknife method is often used for variance estimation in sample surveys but has only been developed for a limited class of sampling designs. We propose a jackknife variance estimator which is defined for any without-replacement unequal probability sampling design. We demonstrate design consistency of this estimator for a broad class of point estimators. A Monte Carlo study shows how the proposed estimator may improve on existing estimators.
Asymptotic Bias in the Linear Mixed Effects Model Under Non-Ignorable Missing Data Mechanisms
Authors: Saha Chandan , Jones Michael P.
Published: December 2004

In longitudinal studies, missingness of data is often an unavoidable problem. Estimators from the linear mixed effects model assume that missing data are missing at random. However, estimators are biased when this assumption is not met. In the paper, theoretical results for the asymptotic bias are established under non-ignorable drop-out, drop-in and other missing data patterns. The asymptotic bias is large when the drop-out subjects have only one or no observation, especially for slope-related parameters of the linear mixed effects model. In the drop-in case, intercept-related parameter estimators show substantial asymptotic bias when subjects enter late in the study. Eight other missing data patterns are considered and these produce asymptotic biases of a variety of magnitudes.
Proanthocyanidins – a final frontier in flavonoid research?
Authors: Dixon Richard A. , Xie De‐Yu , Sharma Shashi B.
Published: December 2004

Proanthocyanidins are oligomeric and polymeric end products of the flavonoid biosynthetic pathway. They are present in the fruits, bark, leaves and seeds of many plants, where they provide protection against predation. At the same time they give flavor and astringency to beverages such as wine, fruit juices and teas, and are increasingly recognized as having beneficial effects on human health. The presence of proanthocyanidins is also a major quality factor for forage crops. The past 2 years have seen important breakthroughs in our understanding of the biosynthesis of the building blocks of proanthocyanidins, the flavan‐3‐ols (+)‐catechin and (–)‐epicatechin. However, virtually nothing is known about the ways in which these units are assembled into the corresponding oligomers in vivo. Molecular genetic approaches are leading to an understanding of the regulatory genes that control proanthocyanidin biosynthesis, and this information, together with increased knowledge of the enzymes specific for the pathway, will facilitate the genetic engineering of plants for introduction of value‐added nutraceutical and forage quality traits.

Contents

Summary
9

I.
Introduction
9

II.
Sources and structures of proanthocyanidins
10

III.
Functions of proanthocyanidins in the plant
12

IV.
Proanthocyanidins and plant quality traits
13

V.
Flavanols, proanthocyanidins and human health
14

VI.
Biosynthesis of proanthocyanidins
16

VII.
Genetic manipulation of the proanthocyanidin pathway
23

VIII.
Conclusions and future prospects
24

Acknowledgements
25

References
25
On‐line executive control: An electromyographic study
Authors: Allain Sonia , Carbonnell Laurence , Burle Boris , Hasbroucq Thierry , Vidal Franck
Published: December 2004

In a choice reaction time (RT) task, electromyographic (EMG) recordings allowed us to fractionate RT into two subcomponents, namely premotor time and motor time. This has been done for correct trials and errors. The analysis of the EMG burst and motor time (between EMG onset and overt response) showed that the EMG burst amplitude was reduced and the motor time was longer for errors than for correct responses. In the same way as posterror slowing on the RT was interpreted as revealing between‐trials changes in executive control, the present data provide direct evidence for an on‐line, within‐trial, executive control.
Similarities and Differences in Women's Sexual Assault Experiences Based on Tactics Used by the Perpetrator
Authors: Abbey Antonia , BeShears Renee , Clinton-Sherrod A. Monique , McAuslan Pam
Published: December 2004

Only a few studies have examined the characteristics of sexual assault based on the tactics used by the perpetrator. In this study we compared the experiences of women who were forced to engage in vaginal, anal, or oral intercourse due to verbal coercion, physical force, or intoxication. Random-digit dialing was used to obtain a sample of 272 single African American and Caucasian women between the ages of 18 and 49 from the Detroit metropolitan area. Participants completed a computer-assisted self-interview that asked detailed questions about a past sexual assault and their reactions to it. Among the 139 women who were forced to engage in vaginal, anal, or oral intercourse, sexual assaults that involved physical force produced the most severe negative outcomes. Situations that involved the woman being too intoxicated to resist differed from others primarily in terms of how much alcohol the man and woman consumed. Although all types of sexual assault were perceived as being at least moderately serious, verbally coerced assaults were on average perceived as being least serious. These findings suggest that the perpetrators' tactics affect women's responses to sexual assault.
Disavowing Social Identities: What it Means When Women Say, “I'm not a Feminist, But …”
Authors: Zucker Alyssa N.
Published: December 2004

Many women, even as they embrace feminist principles, are loath to be labeled feminists. This study presents a measure of feminist identity that accounts for beliefs and behaviors of self-identified feminists and nonfeminists, and for a third group, egalitarians, who endorse liberal feminist beliefs but reject the feminist label. In a sample of 272 college-educated women, a MANOVA showed egalitarians had levels of feminist consciousness between nonfeminists and feminists. Egalitarians did not differ from nonfeminists on favorable conditions for feminist identity or on feminist activism, but both groups scored lower on these measures than feminists. In a hierarchical multiple regression, feminist identity was a significant predictor of feminist activism, above and beyond favorable conditions and barriers. The importance of self-labeling for invisible and stigmatized social identities is discussed.
Best Practice No 180Nephrectomy for renal tumour; dissection guide and dataset
Authors: Fleming S , Griffiths D F R
Published: December 2004

Renal tumours constitute 2.5% of all malignancies and are among the 10 most common malignancies in the UK. Most of these are renal cell carcinomas (RCC) of various subtypes. Although historically RCC has been shown to be resistant to radiotherapy and chemotherapy, recent data suggest that the use of biological treatments, such as adjuvants, may be beneficial in patients with disease that has progressed at the time of presentation. The accurate diagnosis, staging, and grading of RCC is now a crucial element in optimal patient management. There are data to support the importance of histological type, tumour size, stage (especially patterns of extrarenal spread), and grade in determining outcome, and these data have been used to develop the published classification (Heidelberg/Rochester), staging (TNM), and grading (Fuhrman) systems. This article describes a dissection and histological sampling protocol that has been shown to increase the yield of staging information, a guide to histological classification and grading, and finally a minimum dataset for the completion of a satisfactory pathology report.
ALTERNATIVE CALCULATION OF THE PHYSICAL MASS OF THE ρ-MESON
Authors: MORONES RUBEN , MEJIA-ROSALES SERGIO
Published: December 2004

We have derived an expression for the physical mass and width of the ρ-meson in vacuum from its spectral function, calculated in the vector meson dominance model when a ρ0meson couples to two virtual pions π+–π-. The propagator is computed after evaluating the ρ-meson self-energy. The real part of the ρ-meson self-energy is given by a divergent integral and needs to be regularized; the regularization is done by using a double subtracted dispersion relation. The result leads to a closed analytical expression which allow us to evaluate the spectral function in a closed way. The physical mass, defined as the magnitude of the four-momentum |k| for which the spectral function S(k2) attains its maximum value, is obtained, and it gives a value of 770 MeV, which is in total agreement with the reported experimental value of the ρ-meson mass.
AN ALTERNATIVE MODEL FOR THE DUFFIN–KEMMER–PETIAU OSCILLATOR
Authors: KULIKOV D. A. , TUTIK R. S. , YAROSHENKO A. P.
Published: December 2004

A new oscillator model with different form of the non-minimal substitution within the framework of the Duffin–Kemmer–Petiau equation is offered. The model possesses exact solutions and a discrete spectrum of high degeneracy. The distinctive property of the proposed model is the lack of the spin-orbit interaction, being typical for other relativistic models with the non-minimal substitution, and the different value of the zero-point energy in comparison with that for the Duffin–Kemmer–Petiau oscillator described in the literature.
MATHEMATICAL AND NUMERICAL ANALYSIS OF A THREE-DIMENSIONAL FLUID FLOW MODEL IN GLACIOLOGY
Authors: RAPPAZ JACQUES , REIST ADRIAN
Published: December 2004

The main goal of this article is to analyze a three-dimensional model for stress and velocity fields in grounded glaciers and ice sheets including the role of normal deviatoric stress gradients. This model leads to a nonlinear system of stationary partial differential equations for the velocity with a viscosity depending on the stress–tensor but which is not explicitly depending on the velocity. The existence and uniqueness of a weak solution corresponding to this model is established by using the calculus of variations. The approximation of this model is made by a finite element method with piecewise polynomial functions of degree 1 on a tetrahedral mesh and error analysis is performed. Numerical solutions show that the theoretical results we have obtained are almost optimal.
ELLIPTIC EQUATIONS IN ℝ2 WITH ONE-SIDED EXPONENTIAL GROWTH
Authors: ZHANG ZHITAO , CALANCHI MARTA , RUF BERNHARD
Published: December 2004

We consider elliptic equations in bounded domains Ω⊂ℝ2 with nonlinearities which have exponential growth at +∞ (subcritical and critical growth, respectively) and linear growth λ at -∞, with λ>λ1, the first eigen value of the Laplacian. We prove that such equations have at least two solutions for certain forcing terms; one solution is negative, the other one is sign-changing. Some critical groups and Morse index of these solutions are given. Also the case λ<λ1 is considered.
THE REGION OF SOLVABILITY OF A PARAMETERIZED BOUNDARY VALUE PROBLEM CAN BE DISCONNECTED
Authors: UREÑA ANTONIO J.
Published: December 2004

A celebrated result by Amann, Ambrosetti and Mancini [1] implies the connectedness of the region of existence for some parameter-depending boundary value problems which are resonant at the first eigenvalue. The analogous thing does not hold for problems which are resonant at the second eigenvalue.
GRADIENT DRIVEN AND SINGULAR FLUX BLOWUP OF SMOOTH SOLUTIONS TO HYPERBOLIC SYSTEMS OF CONSERVATION LAWS
Authors: JENSSEN HELGE KRISTIAN , YOUNG ROBIN
Published: December 2004

We consider two new classes of examples of sup-norm blowup in finite time for strictly hyperbolic systems of conservation laws. The explosive growth in amplitude is caused either by a gradient catastrophe or by a singularity in the flux function. The examples show that solutions of uniformly strictly hyperbolic systems can remain as smooth as the initial data until the time of blowup. Consequently, blowup in amplitude is not necessarily strictly preceded by shock formation.
LOCAL EXISTENCE AND CONTINUATION CRITERIA FOR SOLUTIONS OF THE EINSTEIN–VLASOV-SCALAR FIELD SYSTEM WITH SURFACE SYMMETRY
Authors: TEGANKONG D. , NOUTCHEGUEME N. , RENDALL A. D.
Published: December 2004

We prove in the cases of spherical, plane and hyperbolic symmetry a local in time existence theorem and continuation criteria for cosmological solutions of the Einstein–Vlasov-scalar field system, with the sources generated by a distribution function and a scalar field, subject to the Vlasov and wave equations respectively. This system describes the evolution of self-gravitating collisionless matter and scalar waves within the context of general relativity. In the case where the only source is a scalar field it is shown that a global existence result can be deduced from the general theorem.
GLOBAL EXISTENCE FOR PHASE TRANSITION PROBLEMS VIA A VARIATIONAL SCHEME
Authors: ROHDE CHRISTIAN , THANH MAI DUC
Published: December 2004

We construct approximate solutions of the initial value problem for dynamical phase transition problems via a variational scheme in one space dimension. First, we deal with a local model of phase transition dynamics which contains second and third order spatial derivatives modeling the effects of viscosity and surface tension. Assuming that the initial data are periodic, we prove the convergence of approximate solutions to a weak solution which satisfies the natural dissipation inequality. We note that this result still holds for non-periodic initial data. Second, we consider a model of phase transition dynamics with only Lipschitz continuous stress–strain function which contains a non-local convolution term to take account of surface tension. We also establish the existence of weak solutions. In both cases the proof relies on implicit time discretization and the analysis of a minimization problem at each time step.
Essential roles of a zebrafishprdm1/blimp1homolog in embryo patterning and organogenesis
Authors: Wilm Thomas P. , Solnica-Krezel Lilianna
Published: December 2004

During vertebrate development the dorsal gastrula or Spemann-Mangold organizer orchestrates axis formation largely by limiting the ventralizing and posteriorizing activity of bone morphogenetic proteins (BMPs). In mouse and Xenopus laevis, genes encoding the zinc finger transcriptional repressor Prdm1/Blimp1 (PR domain containing 1, with ZNF domain; previously named B lymphocyte-induced maturation protein 1) were recently shown to be expressed in the visceral endoderm and anterior endomesoderm, respectively,and the prechordal plate of gastrula stage embryos. Later in development Prdm1/Blimp1 is expressed in many other tissues, including pharyngeal arches, limb buds, otic vesicles, photoreceptor cell layer, slow muscle and cloaca. Based on misexpression and dominant-negative studies, Prdm1/Blimp1 was proposed to promote anterior endomesoderm and head development in Xenopus laevis. Here we report the isolation and functional characterization of zebrafish prdm1 exhibiting a dynamic and evolutionarily conserved expression pattern. Misexpression of prdm1 inhibits the formation of dorsoanterior structures and reduces expression of chordin, which encodes a BMP antagonist. Conversely, interference with Prdm1 translation using antisense morpholino oligonucleotides, increases chordinexpression, while reducing expression of Bmp genes, and consequently dorsalizing the embryo. At the end of the gastrula period, prdm1morphant embryos have enlarged animal-vegetal and anteroposterior embryonic axes. This altered embryo morphology is associated with augmented extension movements of dorsal tissues and normal posterior migration of ventral tissues. Additionally, Prdm1 activity is essential for proper development of slow muscle, the photoreceptor cell layer, branchial arches and pectoral fins. Our studies reveal essential roles for prdm1 in limiting the function of the gastrula organizer and regulating cell fate specification and morphogenetic processes in precise correspondence with its intricate expression pattern.
Spawning Season and Nest Fidelity of Largemouth Bass in a Tropical Reservoir
Authors: Waters D. Scott , Noble Richard L.
Published: December 2004

Largemouth bass Micropterus salmoides, an intensively studied sport fish of temperate North America, have been introduced into tropical regions, but with little evaluation. Studies in Puerto Rico suggest that reproduction occurs over many months and that life spans are short and annual mortality rates high. We tracked 44 adult largemouth bass with ultrasonic telemetry over an 18-month period (two spawning seasons) to determine the temporal and spatial utilization of spawning grounds. During the 1998 spawning season, both males and females demonstrated high site fidelity to specific areas characteristic of spawning grounds over the first half of the calendar year. Within this period, two distinct spawning events were evident from fish movements and were subsequently verified by hatch frequencies of young. The two spawning events, from mid-January through March and from late May through June, coincided with highly fluctuating water levels. When levels were high, shallow, vegetated areas were available and used for spawning. The reoccupation of nest areas corroborates previous gonad analyses that suggested multiple partial spawns by individual fish. During the 1999 spawning season, water levels were high in January and spawning occurred for 3 weeks, but levels rapidly declined thereafter, minimizing reproduction. Both male and female largemouth bass exhibited strong homing and nest site fidelity by returning to previous nesting areas. Individual fish were observed nesting in the same spawning grounds, and several males repeatedly utilized the same nest site during each of the separate spawning events and during both years. Because in tropical reservoirs recruitment to the fishable largemouth bass stock is directly related to the abundance of age-0 fish, maintaining high, stable water levels during the spawning season should enhance the largemouth bass population.
Use of Prepositioned Areal Electrofishing Devices with Rod Electrodes in Small Streams
Authors: Schwartz John S. , Herricks Edwin E.
Published: December 2004

We describe the design, performance, and operation of prepositioned areal electrofishing devices (PAEDs) that use rod electrodes for sampling fish in mesohabitat units of a small stream. The flexibility in design offered by rod PAED designs is an improvement over previously reported designs and provides the capacity to specifically match fish immobilization range with varying mesohabitat shape and size under typical field sampling conditions. In our study, immobilization range was determined as the distance from an electrode at which a given voltage gradient (V/cm) resulted in immobilization of several warmwater fish species. For waters with a specific conductivity of about 700 μS/cm, the immobilization threshold was 0.14 V/cm for the 16 species tested. The maximum immobilization range was about 0.85 m when 350 V or more were applied to the rod PAEDs. We evaluated rod PAED performance by considering the effects of electrode length, electrode orientation, and voltage supply on voltage gradients around the electrodes. The results were used to develop general protocols for rod PAED operation. In three scenarios, we documented that electrode placement and voltage adjustment can be used to sample fish in 1.2–16.9-m2 mesohabitats at water depths up to 1.3 m. Based on the general protocols developed and outlined in this study, rod PAEDs can be used to quantify fish occupancy in the diverse set of mesohabitats commonly found in small streams.
An Evaluation of 5.87-cm and 6.03-cm Escape Rings for Blue Crab Callinectes sapidus Traps
Authors: Guillory Vincent , Allemand Ralph , King Kenny , Bare Lisa
Published: December 2004

Escape rings are used in traps for blue crab Callinectes sapidus to reduce sublegal (<127 mm carapace width [CW]) catch. Two escape ring sizes (5.87 cm and 6.03 cm) were compared using laboratory-derived retention curves and catch data from control traps without rings and experimental traps with one of the two rings. Percent sublegal catch and large sublegal (117– 126 mm CW) catch per unit effort (CPUE) was significantly greater in traps with 5.87-cm rings than in traps with 6.03-cm rings. Catch per unit effort of legal (≥127 mm CW) blue crabs was not significantly different between the two experimental traps, although small legal (127–136 mm CW) CPUE was significantly lower in traps with 6.03 rings. The modal size of blue crabs increased from control traps to traps with 5.87-cm rings to traps with 6.03-cm rings. Retention curves by 5-mm size-groups corroborated trends depicted by field data. A lower retention of females than males was demonstrated. The larger escape ring was recommended to maximize the benefits of sublegal crab CPUE reduction.
Gear Effects on Marine Habitats: Harvesting Northern Quahogs in a Shallow Sandy Bed at Two Levels of Intensity with a Short Rake
Authors: MacKenzie Clyde L. , Pikanowski Robert
Published: December 2004

We studied the effects on invertebrate infauna and grain size of harvesting northern quahogs Mercenaria mercenaria with a short rake. The substrate was a mixture of medium-coarse sand (phi values, 0.847–1.159) that was covered by 0.5 m of water at low tide. Two experimental areas (I + II) in Raritan Bay, New Jersey, were subdivided into six 5.5-m × 5.5-m plots. We raked alternate plots, the unraked plots serving as controls. In area I, we raked the treatment plots once (in June 2000) and then sampled all plots for effects on invertebrates and grain size. The number of invertebrates in the five taxa we counted and the mean grain size did not differ significantly (P > 0.05) between treatment and control. In area II, we raked the treatment plots three times, one month apart (in July, August, and September 2000) and then sampled all plots. The results for invertebrates and grain size were similar to those for area I. This study suggests that short raking once or repeatedly during a harvesting season in a shallow sandy substrate does not measurably alter numbers of invertebrates or sediment grain size.
Implications of a Migration Impediment on Shortnose Sturgeon Spawning
Authors: Cooke Douglas W. , Leach Steven D.
Published: December 2004

A population of shortnose sturgeon Acipenser brevirostrum was documented congregating at the base of Pinopolis Dam, Cooper River, South Carolina, during the February−March spawning season. Pinopolis Dam is a peaking hydroelectric facility and navigation lock located within the coastal plane, 77 km upriver of the mouth of the Cooper River at Charleston, South Carolina. In a 5-year radiotelemetry experiment, shortnose sturgeon did not pass upstream through the navigation lock but congregated at the base of the dam. As a result, a study was conducted to determine whether the tailrace was used as spawning habitat. The location is atypical of published descriptions of shortnose sturgeon spawning habitat in terms of a suite of characters, including distance upriver, tide, flow characteristics, and substrate. The river is tidally influenced for its entire length, and the bottom substrate in the tailrace is dominated by hard marl with negligible fine sediments such as silt and sand. Turbine discharge varies from 0 to 329 m3/s subdaily; current velocities during typical hydroelectric peaking discharge exceed 3 m/s. Egg sampling showed that successful spawning (i.e., fertilized eggs and developing embryos) occurred during the three spawning seasons sampled. Spawning was detected from 27 February through 29 March (1997–1999) at water temperatures ranging from 11.5°C to 19.0°C (mean = 14.5°C), reaching the highest levels published for shortnose sturgeon spawning. Active spawning and lack of upstream passage by shortnose sturgeon at this site suggest that physical blockage of migration may prevent fish from reaching preferred spawning habitat, probably to the detriment of the population.
Performance of Two Strains of Lake Trout Stocked in the Midlake Refuge of Lake Michigan
Authors: McKee Patrick C. , Toneys Michael L. , Hansen Michael J. , Holey Mark E.
Published: December 2004

To evaluate the performance of Seneca and Marquette strains of lake trout Salvelinus namaycush for restoring stocks in southern Lake Michigan, we compared relative abundance (fish per lift of 305 m of gill net), survival (slope of the decline in natural logarithms of relative abundance), growth (von Bertalanffy growth curves), and wounding rates by sea lamprey Petromyzon marinus of the 1984 and 1985 year-classes captured at ages 3–16 in fall gill-net assessments on the Sheboygan Reef and the Milwaukee nearshore area during 1987–2000. Marquette strain lake trout survived at a significantly higher rate than Seneca strain lake trout prior to age 3 but at similar rates after age 3. The 1984 year-class of lake trout survived at a significantly higher rate than the 1985 year-class of lake trout prior to age 3 but at similar rates after age 3. Emigration of lake trout from the Sheboygan Reef to the nearshore Milwaukee area was similar for the Marquette and Seneca strains but was higher for the 1984 year-class than the 1985 year-class. The mean relative abundance of the 1984 and 1985 year-classes of Marquette and Seneca strains of lake trout varied erratically with age but did not decline with age on the Sheboygan Reef and Milwaukee nearshore area. On the Sheboygan Reef, growth in length, expressed as asymptotic length (L∞), differed significantly between the Marquette and Seneca strains of lake trout but did not differ significantly between the 1984 and 1985 year-classes. On the Sheboygan Reef, wounding rates by sea lampreys did not differ significantly between the Marquette and Seneca strains of lake trout among size-classes (633–734, 735–836, and ≥837 mm) during 1994–2000. Our findings suggest that the performance of Marquette strain lake trout was superior to that of Seneca strain lake trout on the Sheboygan Reef in central Lake Michigan.
A Comparison of Atlantic Salmon Embryo and Fry Stocking in the Salmon River, New York
Authors: Coghlan Stephen M. , Ringler Neil H.
Published: December 2004

To assess the feasibility of restoring an extirpated species, it is crucial to identify the method of reintroduction that optimizes juvenile survival and growth so that adequate adult populations may be established. Because Atlantic salmon Salmo salar fry are relatively expensive to rear, we compared the efficacies of two embryo-stocking methods and one fry-stocking method in producing age-0 Atlantic salmon parr in the Salmon River, New York. As measured by resulting parr densities, there were no differences in survival rates between embryos stocked with and without protective hatching boxes; the mean survival of embryo-stocked fish to late summer was less than 0.01%. Fry stocking produced significantly greater densities of late-summer parr than did embryo stocking, with site-specific survival ranging up to 8%; the mean survival of fry was 2%. Considering the hatchery costs of rearing each life stage, the labor involved in stocking, and the resulting late-summer parr abundances, we recommend planting fry rather than embryos as a method of reintroducing Atlantic salmon. Additional studies are needed to evaluate the success of stocking older life stages of Atlantic salmon in the Salmon River, although factors other than juvenile survival are probably important in establishing and maintaining a spawning population.
Superconductivity at 7.5 K and ambient pressure in polycrystalline pressed samples of βp‐(BEDT‐TTF)2I3
Authors: Schweitzer Dieter , Gogu Emil , Grimm Hans , Kahlich Siegfried , Keller Heimo J.
Published: December 2004

Polycrystalline pressed samples of β‐(BEDT‐TTF)2I3 exhibit bulk superconductivity, zero resistivity being observed at 3.2 K (see figure) a transition temperature which is surprisingly higher than that observed for single crystals of the same compound.

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Potassium lithium niobate: A frequency doubler for (Al,Ga)As lasers
Authors: Ouwerkerk Martin
Published: December 2004

Research News: Doubling the frequency of light from an (Al,Ga)As laser quadruples its spot density and also, therefore, the amount of information which can be stored on an optical disc. By varying the lithium content of the title compound a frequency doubling material has been developed which can be tuned from 720 to over 920 nm producing a highly efficient blue laser capable of high‐density optical recording.
The effect of arsenicals on cell suspension cultures of the Madagascar periwinkle (Catharanthus roseus)
Authors: Cullen William R , Hettipathirana Deepthi , Reglinski John
Published: December 2004

Catharanthus roseus cells were grown in the presence of arsenite, arsenate, methylarsonate and dimethylarsinate. Cell growth and arsenical uptake were monitored. Reduction of arsenate, methylation of arsenic and demethylation of methylarsenic species are described. Alkaloid production by the cells is dramatically influenced by the presence of arsenicals. 1H NMR studies of methylarsonate uptake by whole cells of C. roseus are reported.
Soluble metal–polymer catalysts in the hydrogenation of organic compounds
Authors: Karakhanov E A , Neimerovets E B , Dedov A G
Published: December 2004

Literature describing the use of soluble metal–polymer catalysts in the molecular hydrogenation of alkenes, alkynes, aromatic and heterocyclic compounds has been reviewed. Special attention has been paid to coordinated metallic and organometallic catalytic systems and highly dispersed colloidal metals stabilized with polymers. The influence of metals, polymers and solvents on the structures of active sites is discussed. The prospects for the application of soluble metal–polymer catalysts in organic synthesis are also considered.
Studies of the uptake and binding of trace metals in fungi. Part I: Accumulation and characterization of mercury and silver in the cultivated mushroom, Agaricus bisporus
Authors: Byrne A R , Tušek‐Žnidarič M
Published: December 2004

The champignon mushroom Agaricus bisporus was cultivated on compost labelled with the radioactive traers 110mAg and 203Hg and the uptake of these two metals studied. The radiotracer then served as an aid in elucidation and characterization of the fungal metal–protein species using gel chromatography. In the case of the silver–protein complex, but not of mercury, the majority of the metal was contained in the fractions of intermediate (ca 8000–10000 Da) molecular weight possibly corresponding to metallothioneins (MT) or MT‐like species.
An organometallic route for the preparation of ring‐substituted 2‐aryl‐propanoic and ‐butanoic acids
Authors: Gruselle M , Malezieux B , Jaouen G , Troitskaya L L , Sokolov V I
Published: December 2004

This communication presents a simple and efficient way to synthesize 2‐arylalkanoic acids via chromium carbonyl complexation.
Chromatography of organic derivatives of group IVB elements
Authors: Belikov V A , Shatz V D , Lukevics E
Published: December 2004

Chromatographic aspects of the analysis of Group IV organometallic derivatives are reviewed. The emphasis is towards gas and liquid chromatography.
Bioturbation recorded by a sedimentary siloxane horizon
Authors: Pellenbarg Robert E , Carhart Homer W
Published: December 2004

A Puget Sound (Washington State, USA) sediment core was quantitatively analyzed for organic silicon content, as derived from post‐1945 release of poly(organo)siloxanes (silicones). The sedimentary silicone data record and preserve a smeared event horizon, dating the first appearance of silicones in the sediment column. This record of bioturbation preserved deep in the column appears somewhat in contrast to the record provided by 210Pb geochronology. Aliquots of the same core segments had been dated previously using 210Pb, and analyzed for silicone content, as reported in this study. Core samples older than 50 years showed no detectable silicone, as measured by a new procedure utilizing inductively coupled plasma emission spectroscopy, after solvent extraction to collect the silicone from gram‐sized sediment core samples.
Fluorescent humic substances and blackfoot disease in Taiwan
Authors: Lu Fung‐Jou
Published: December 2004

Blackfoot disease is endemic in Chia Yi and Tainan Counties in south‐western Taiwan. Arsenic present in the drinking water taken from wells has been blamed for causing this disease. The discovery in 1975 of fluorescent compounds in these well waters led to the isolation of these substances, to their identification as humic substances containing a large number of elements (among them arsenic), and to the development of an animal model for blackfoot disease. Mice receiving aqueous solutions of these fluorescent substances at a daily dose of 5 mg per 20 g body mass for at least 22 days developed blackfoot and blacktail disease. Work with these fluorescent substances, their chemical properties, and their biological actions is reviewed.
Synthesis, characterization and in vitro antitumour activity of a series of substituted 2,2‐di‐n‐butyl‐4‐oxo‐benzo‐1,3,2‐dioxastannins
Authors: Bouǎlam Mohammed , Willem Rudolph , Gelan Jan , Sebald Angelika , Lelieveld Peter , de Vos Dick , Gielen Marcel
Published: December 2004

The characterization by 1D and/or 2D 1H NMR, 13C NMR, 119Sn NMR, Mössbauer and mass spectrometry of a series of di‐n‐butyltin derivatives of 3‐, 4‐, and 5‐methyl‐, 3‐, 4‐, and 5‐methoxy‐, 4‐ and 5‐amino‐substituted, and 3,5‐diiodo‐salicyclic acids is described. Their NMR spectra suggest that they are present as dimers in CDCl3 solution, like the di‐n‐butyltin derivative of unsubstituted salicyclic acid. This has been confirmed by the observation of mixed dimers. The insoluble derivatives have been characterizerd by solid state cross polarization/magic angle spinning (CP/MAS) 13C and/or 119Sn NMR, Mössbauer and mass spectroscopy. These compounds are characterized in vitro by a lower inhibition dose than cis‐platin or etoposide against a series of five human cell lines.