bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective effects of an herbal formulation of Radix Astragali, Radix Codonopsis and Cortex Lycii on streptozotocin‐induced apoptosis in pancreatic β‐cells: an implication for its treatment of diabetes mellitus
Authors: Chan Judy Yuet‐Wa , Leung Ping‐Chung , Che Chun‐Tao , Fung Kwok‐Pui
Published: August 2007

Hyperglycemia is one of the main causes of oxidative stress in type 2 diabetes mellitus. During hyperglycemia, the increased level of various reducing sugars in the blood enhances the production of reactive oxygen species (ROS) and triggers tissue damage, especially in pancreatic β‐cells. Streptozotocin (STZ) is a diabetogen that causes diabetes mellitus via ROS‐induced apoptosis in β‐cells. In this study, SR10, an herbal formulation consisting of the aqueous extracts of Radix Astragali, Radix Codonopsis and Cortex Lycii was examined for its antidiabetic effects in vitro. SR10 treatment resulted in significant enhancement of survival rate of rat pancreatic β‐cells which were treated by streptozotocin. SR10 apparently reduced apoptosis of streptozotocin‐treated β‐cells by decreasing DNA fragmentation, sub‐G1 peak area and percentage of apoptotic cells. Nitric oxide (NO) production in streptozotocin‐treated cells was inhibited by SR10 via the suppression of the expression of inducible nitric oxide synthase (iNOS). The implication of SR10 in treating type 2 diabetes mellitus was discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Quinic acid esters from Pluchea indica with collagenase, MMP‐2 and MMP‐9 inhibitory activities
Authors: Ohtsuki Takashi , Yokosawa Emiko , Koyano Takashi , Preeprame Srisomporn , Kowithayakorn Thaworn , Sakai Shinobu , Toida Toshihiko , Ishibashi Masami
Published: August 2007

Investigation of collagenase inhibitory natural components afforded two quinic acid esters (1 and 2) and quercetin (3) from the leaves of Pluchea indica (Compositae). Of these, compounds 1 and 2 exhibited collagenase inhibitory activity (IC50) at a concentration of less than 10 µm, and 1 showed matrix metalloproteinase (MMP)‐2 and ‐9 inhibitory activity (IC50) at 2.5 and 6.4 µm, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
The connected‐moments polynomial approach for Hamiltonian eigenvalues calculation and its application to the one‐particle systems
Authors: Bartashevich Igor
Published: August 2007

The new connected‐moments polynomial approach (CMP) is developed for evaluation of Hamiltonian eigenvalues. It is based on properties of specially designed polynomial and does not use any basis set and variational procedure. Like all the methods based on hamiltonain moments knowledge, the CMP is conceptually simple but is less tedious and is usually convergent even for very “crude” trial functions. This method is applicable not only to the ground state energy calculation but also to the excited states. The formalism is presented in two modifications: non‐local (integral) and local (integral‐free) ones. An accuracy of both versions is illustrated by numerical examples of Hamiltonian eigenvalues calculations for harmonic and anharmonic oscillators. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Determinant factors in the degree of implementation of Local Agenda 21 in the European Union
Authors: Garcia‐Sanchez Isabel M. , Prado‐Lorenzo Jose‐Manuel
Published: August 2007

The concern for sustainable development reached its greatest form of expression in what is known as the Brundtland Report; however, it was the Rio de Janeiro Conference of 1992 that created the foundations, through agreements such as Agenda 21.

 Though the success of Agenda 21 depends fundamentally on central governments, local administrations can play a decisive role, which is why European cities have taken on a serious commitment to enforce it by way of the Aalborg Charter.

 This paper evaluates the advancements by European municipalities in implementing Local Agenda 21, by identifying their determinant factors. The results show that productive and organizational aspects are key factors, regardless of their origin. Likewise, it has been verified that the factors of promotion instigated by supramunicipal bodies of the public administration are extremely effective, whereas political factors are of little relevance. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
D‐optimal cohort designs for linear mixed‐effects models
Authors: Tekle Fetene B. , Tan Frans E. S. , Berger Martijn P. F.
Published: August 2007

The D‐optimality criterion is used to construct optimal designs for different numbers of independent cohorts, which constitute a number of repeated measurements per subject over time. A cost function for longitudinal data is proposed, and the optimality criterion is optimized taking into account the cost of the study. First, an optimal number of design points for a given number of cohorts and cost was identified. Then, an optimal number of cohorts is identified by comparing the relative efficiencies (REs). A numerical study shows that for models describing the trend of a continuous outcome over time by polynomials, the most efficient number of repeated measurements is equal to the sum of the total number of cohorts and the degree of the polynomial in the model. REs of a purely longitudinal cohort design with only one cohort, and mixed longitudinal and cross‐sectional cohort designs with more cohorts are compared. The results show that a purely longitudinal cohort design with only one cohort of subjects measured at the optimal time points is the most efficient design. The findings in this paper show that one can obtain a highly efficient design for parameter estimation with only a few repeated measurements. The results of this study will reduce the cost of data collection and ease the logistical burdens in cohort studies. Copyright © 2007 John Wiley & Sons, Ltd.
Prenatal diagnosis of diastematomyelia: presentation of eight cases and review of the literature
Authors: Has R. , Yuksel A. , Buyukkurt S. , Kalelioglu I. , Tatli B.
Published: August 2007

Objectives

Diastematomyelia is a rare form of spinal dysraphism. We present eight cases of diastematomyelia diagnosed prenatally in our institution as well as a review of the literature in order to determine the prognosis of isolated cases of this very unusual condition.

Methods

Records of fetuses with diastematomyelia diagnosed in our institution between January 2000 and June 2005 were collected. All liveborn fetuses were examined by a pediatric neurologist. Pre‐ and postnatal data were analyzed. A search was then conducted using PubMed to review previously reported cases in the literature.

Results

Eight cases of diastematomyelia were diagnosed during the study interval. The mean (range) gestational age at diagnosis was 21 (13–25) weeks. The main sonographic findings were widening of the spinal canal in the coronal view and an additional echogenic focus in the posterior part of the spinal column in the axial view. The diagnosis of associated open spina bifida was made in one fetus with elevated levels of amniotic fluid α‐fetoprotein (AF‐AFP) and acetylcholinesterase (AF‐AChE) and the pregnancy was terminated. The other seven cases of diastematomyelia had normal levels of AF‐AFP and AF‐AChE and were considered isolated. One pregnancy miscarried spontaneously 1 week following amniocentesis and the remaining six were delivered at term. Review of the literature revealed 14 reports involving 26 cases of prenatally diagnosed diastematomyelia. Twelve cases had normal biochemistry and/or no additional abnormalities and all had a favorable outcome.

Conclusions

When diastematomyelia is not associated with other spinal anomalies, the prognosis is favorable. Prenatal diagnosis is generally made in the second trimester but sonographic signs may be recognized as early as the first trimester. Intrauterine diagnosis of diastematomyelia should facilitate appropriate management of affected cases. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
The Dynamics of Agricultural Contribution to Economic Growth
Authors: Nissan Edward
Published: August 2007

More than twenty-five years ago, Simon Kuznets formulated some procedures to measure the contribution of the agricultural sector to economic growth and development. This article provides a view of the experience of various countries at different stages of economic development to examine how they fare individually in terms of Kuznets's suggestions. A major objective is the exploration of relationships between the levels of income and agricultural product and labor contribution to economic growth. It was found, as Kuznets perceived, that the contribution declines as the level of income rises.
The Vintage Schooling Hypothesis and Racial Differences in Earnings and On-The-Job Training: A Longitudinal Analysis
Authors: Duncan Kevin C.
Published: August 2007

Why do younger black males earn more relative to whites than do older black males? The literature offers two competing explanations. Smith and Welch suggest this pattern is evidence that employers are rewarding the improved skills of more recently, better-educated blacks. Lazear, and Duncan and Hoffman suggest that the pattern is the result of employer discrimination that prevents blacks from entering occupations that offer on-the-job training (OJT) and wage growth with experience. The competing views are tested by using the National Longitudinal Survey of Labor Market Experience of Young Men to compare black and white earnings and regression estimates in two periods. Regression results for 1968 and 1978 indicate that, as the NLS cohort aged, only white males had an age-earnings profile exhibiting the positive effect of OJT. Over the period, education coefficients decreased for both groups with the reduction greatest in black coefficients. This suggests that the earnings effect of education is not as stable for blacks as it is for whites over the life cycle. Black-white earnings ratios were approximately the same in both periods. The results reported here support the explanations offered by Lazear and by Duncan and Hoffman, implying that policies focusing on eliminating racial differences in educational quality may be insufficient in improving the relative position of blacks over the life cycle.
Urban Neighborhood Demographics Associated with Environmentally Suspect, Tax-Delinquent Properties: Equity and Redevelopment Implications
Authors: Leigh Nancey Green , Gradeck Robert
Published: August 2007

This article focuses on how environmental contamination of urban property, or the perception thereof, acts as a new force in widening inequalities between central cities and the rest of the nation. Environmental contamination, one form of negative neighborhood externality, when linked with a second form, that of tax-delinquent property, become the ultimate neighborhood negative externality, creating a redevelopment impasse under present governmental rules and practice. This problem is explored with a case study of Milwaukee, Wisconsin, examining the incidence of environmentally suspect, tax-delinquent properties by census tracts and associated socioeconomic characteristics of population within these tracts. The article concludes with a discussion of how the market, reinforced by evolving public policy, will begin to eliminate the redevelopment impasse posed by environmentally suspect, tax-delinquent property.
Reverse ventricular remodelling after cardiac resynchronization therapy is associated with a reduction in serum tenascin‐C and plasma matrix metalloproteinase‐9 levels
Authors: Hessel Marleen H.M. , Bleeker Gabe B. , Bax Jeroen J. , Henneman Maureen M. , den Adel Brigit , Klok Margreet , Schalij M.J. , Atsma Douwe E. , van der Laarse Arnoud
Published: August 2007

Background:

In heart failure patients, cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling.

Aim:

The aim of this study was to evaluate whether changes in levels of circulating biomarkers of extracellular matrix metabolism correlate with the response to CRT.

Methods and results:

Clinical parameters, left ventricular (LV) volumes, and circulating levels of tenascin‐C (TNC), matrix metalloproteinase‐2 (MMP‐2), MMP‐9, and amino‐terminal propeptide of brain natriuretic peptide (NT‐proBNP) were assessed in 64 patients at baseline and 6 months follow‐up. The majority of patients (72%) showed a >10% reduction in LV end‐systolic volume at follow‐up, and were classified as responders to CRT. The remaining patients were classified as non‐responders. In responders, a significant decrease in circulating levels of TNC (from 60±40ng/mL to 47±30ng/mL, p<0.01), MMP‐9 (from 55±30 AU to 44±27 AU, p<0.01), and NT‐proBNP (from 2106±1805pg/mL to 1132±1289pg/mL, p<0.001) were observed at follow‐up; MMP‐2 levels were unchanged. In non‐responders TNC, NT‐proBNP, MMP‐9 and MMP‐2 levels remained unchanged.

Conclusion:

At 6months follow‐up, CRT was associated with reverse LV remodelling, and a significant decrease in TNC, MMP‐9, and NT‐proBNP levels. This suggests an important role of ECM modulation in the process of reverse ventricular remodelling in patients responding to CRT.
Broncholithiasis in a cat: clinical findings, long-term evolution and histopathological features
Authors: Talavera Jesus , del Palacio María Josefa Fernandez , Bayon Alejandro , Buendia Antonio J. , Sanchez Joaquin
Published: August 2007

A 14-year-old neutered male Persian cat was evaluated because of an acute exacerbation of a chronic cough of 2–3 years of duration. Physical examination was normal except for the auscultation of accentuated breath sounds and wheezes cranially on both sides of the chest. Complete blood count, biochemical parameters and urinalysis were normal. Thoracic radiographs showed a generalised nodular pattern with multiple mineral opacities. Oral prednisone and doxycycline were prescribed. Two weeks later, the frequency of the cough was significantly reduced. Terbutaline was recommended for relief of acute exacerbations. Three years later the cat was evaluated again due to a non-related disease that led to the euthanasia of the cat. Concerning its respiratory disease, the cat had experienced nearly asymptomatic periods of 3–6 weeks of duration punctuated by acute exacerbation periods of 7–10 days, during which terbutaline was useful to relieve the cough. Thoracic radiographs showed a mild increase in the size and extent of the pulmonary mineralisation. Histopathologically, mild bronchitis and bronchiectasis were evident, accompanied by calcified bronchial plugs and marked hyperplasia and hypertrophy of the seromucinous glands. Based on clinical and pathoanatomical findings, a final diagnosis of miliary broncholithiasis and bronchiectasis was made. Broncholithiasis should be considered in differential diagnosis of pulmonary mineralisation in cats. When no concomitant diseases are present, this rare disease appears to have a slowly progressive evolution that does not appear to carry a bad prognosis and may be satisfactorily managed with combinations of bronchodilators and corticosteroids.
Patterns of intergenerational support in grandparent-grandchild and parent-child relationships in Germany
Authors: HOFF ANDREAS
Published: August 2007

The paper focuses on intergenerational support relations between grandparents and their grandchildren in Germany, and how they have changed from 1996 to 2002. The paper begins with a brief review of the literature on functional aspects of the grandparent-grandchild relationship, after which the research hypotheses about intergenerational support in the relationship are elaborated. Following a description of the data source, theGerman Ageing Survey, and its samples and measures, the evidence on the patterns of grandparents' provision and receipt of intergenerational support to and from their grandchildren are presented and compared with parent-child support patterns. The analysis also considers variations by age groups and birth cohorts and changes over time. The main empirical finding is that there was a greater likelihood of financial transfers to grandchildren in 2002 than six years earlier. Nevertheless, the grandparents' relationships with their grandchildren remained imbalanced or asymmetrical, at the older generation's expense. It was found that financial and instrumental support patterns between grandparents and grandchildren were best explained using an ‘intergenerational stake’ hypothesis rather than one of ‘intergenerational solidarity’; the latter is more consistent with parent-child support patterns.
Old age in Byzantine society
Authors: GILLEARD CHRIS
Published: August 2007

This paper examines the status afforded old age in the Byzantine Empire. Frequently neglected in accounts of state formation or comparative history, this Christian imperial state transformed the moral ordering of the lifecourse. In contrast to both classical Greek and Roman society, old age acquired a distinct moral authority in Byzantine society. This status was not confined to a few members of the elite as in Sparta or Rome. The economic vulnerability, physical frailty and social marginality accompanying old age conferred an equal moral claim upon society that the state actively addressed. A mix of institutionalised and individual charities created a prototype ‘welfare state’ within which provision for old age played a significant part. Despite its neglect by most social historians of old age, the Byzantine Empire is of considerable historical significance in the development of the contemporary constructions of old age. Just as the Byzantine Empire helped erode the practice of slavery that had been widespread in the ancient Greek and Roman societies, so too did it help to create a prototype welfare state in which individual enterprise was tempered by a collective sense of inclusive Christian responsibility. The consideration extended by Byzantine society, to old age, to its weakness as well as to its wisdom and authority, instituted a step change from earlier classical traditions.
Does gradual retirement have better outcomes than abrupt retirement? Results from an Australian panel study
Authors: DE VAUS DAVID , WELLS YVONNE , KENDIG HAL , QUINE SUSAN
Published: August 2007

Conventional wisdom promotes gradual retirement rather than an abrupt end to the working life. This paper compares the outcomes of abrupt and gradual retirement one and three years after the transition to retirement began using data from an Australian panel study. The outcomes included changes in health, positive and negative affect, wellbeing and marital cohesion. For many outcomes there was no difference between gradual and abrupt retirements, but those who retired abruptly were more likely to rate their health as having deteriorated and more likely to report better adjustment to retirement. Control over retirement decisions was also explored; it emerged as a more important factor in retirement wellbeing than whether the transition was gradual or abrupt. The absence of interaction or additive effects between the retirement pathway and the level of control over the process confirmed this result. Thus there is no simple answer to the question in the title. Retiring gradually allows time for people to make changes to their lifestyle, but having control over the timing and manner of leaving work had a greater positive impact on psychological and social wellbeing, and this persisted three years after retirement. The findings suggest that policies and employment practices that promote employees' control of their retirement decisions will enhance wellbeing in later life and facilitate longer workforce participation.
Becoming and being gendered through the body: older women, their mothers and body image
Authors: CLARKE LAURA HURD , GRIFFIN MERIDITH
Published: August 2007

Following West and Zimmerman's (1987) theoretical understanding of how gender identities are created and maintained, this paper examines the ways in which older women learned from their mothers how ‘to do gender’ through their bodies and specifically their physical appearances. Extracts from semi-structured interviews with 44 women aged 50 to 70 years have been drawn upon to identify and discuss the ways in which women perceive, manage and present their bodies using socially-constructed ideals of beauty and femininity. More specifically, three ways that women learned ‘to do gender’ are examined: from their mothers' criticisms and compliments about their appearance at different stages of the lifecourse; from their mothers' attitudes towards their own bodies when young and in late adulthood; and from the interviewees' own later-life experiences and choices about ‘beauty work’. Interpretative feminism is employed to analyse how the women exercised agency while constructing body-image meanings in a social context that judges women on their ability to achieve and maintain the prevailing ideal of female beauty. The study extends previous research into the influence of the mother-daughter relationship on young women's body image. The findings suggest that mothers are important influences on their daughters' socialisation into body-image and beauty work, and exert, or are perceived to exert, accountability across the life-course.
Development of a new buffing robot manipulator for shoes
Authors: Choi Hyeung-Sik , Hwang Gyu-Deuk , You Sam-Sang
Published: August 2007

This paper presents analysis and experimental verifications of a new robot manipulator with five degrees of freedom developed for the buffing operation of shoes. First, the forward and inverse kinematics are analyzed. Next, an analytic closed-form solution is rigorously derived for the joint angles corresponding to the position and orientation of the end-effector in Cartesian coordinates. A control system, including input/output interfaces and the related electronic system, is designed for the control of the mechanical structure of the buffing robot. Then, peripheral systems integrated with the conveyer, transfer device, and fixture device are designed for the sequential buffing process of shoes. Also, a graphic user interface (GUI) program including the forward/inverse kinematics, control algorithm, and communication program to interact the robot with the peripheral systems is developed by using visual C++ language. A new flexible toolholder (FTH) is proposed to compensate for the excessive applied force between deburring tools and shoes. Finally, the test results are provided to demonstrate the effectiveness of the proposed scheme.
The Non-identity Fallacy: Harm, Probability and Another Look at Parfit's Depletion Example
Authors: ROBERTS M. A.
Published: August 2007

The non-identity problem is really a collection of problems having distinct logical features. For that reason, non-identity problems can be typed. This article focuses on just one type of non-identity problem, the ‘can't-expect-better’ problem, which includes Derek Parfit's depletion example and many others. The can't-expect-better problem uses an assessment about the low probability of any particular person's coming into existence to reason that an earlier wrong act does not harm that person. This article argues that that line of reasoning is unusually treacherous in that it makes not just one hard-to-detect error in what is done with the relevant probability assessments but rather alternates between two. We sort out one fallacy only to fall, against all odds (as it were), into a second. By avoiding both errors, we become able to discern harm in cases in which the can't-expect-better problem argues there is none. We will then be in a position to set aside the can't-expect-better problem as an objection against the person-based intuition that acts that are ‘bad’ must be ‘bad for’ at least some existing or future person.
Mill and the Secret Ballot: Beyond Coercion and Corruption
Authors: LEVER ANNABELLE
Published: August 2007

In Considerations on Representative Government, John Stuart Mill concedes that secrecy in voting is sometimes justified but, nonetheless, maintains that it should be the exception rather than the rule. This article critically examines Mill's arguments. It shows that Mill's idea of voting depends on a sharp public/private distinction which is difficult to square with democratic ideas about the different powers and responsibilities of voters and their representatives, or with legitimate differences of belief and interest amongst voters themselves. Hence, it concludes, we should reject the assumption, which many of us share with Mill, that the secret ballot is justified only on prudential grounds and recognize how central privacy is to any democratic conception of citizenship and politics.
The Nature of Pleasure: A Critique of Feldman
Authors: MASON ELINOR
Published: August 2007

In these remarks on Feldman's recent book, Pleasure and the Good Life, I concentrate on Feldman's account of pleasure as attitudinal. I argue that an account of pleasure according to which pleasure need not have any feel is implausible. I suggest that Feldman could avoid this problem but retain the advantages of his attitudinal hedonism by giving an account of the attitude ‘taking pleasure in’ such that the attitude has a feel.
Ancestral roles of glia suggested by the nervous system of Caenorhabditis elegans
Authors: Heiman Maxwell G. , Shaham Shai
Published: August 2007

The nematode Caenorhabditis elegans has a simple nervous system with glia restricted primarily to sensory organs. Some of the activities that would be provided by glia in the mammalian nervous system are either absent or provided by non-glial cell types in C. elegans, with only a select set of mammalian glial activities being similarly provided by specialized glial cells in this animal. These observations suggest that ancestral roles of glia may be to modulate neuronal morphology and neuronal sensitivity in sensory organs.
Welche Faktoren beeinflussen die Arbeitszufriedenheit und -motivation an einem Institut für Radiologie?
Authors: Unterweger  , Imhof  , Mohr  , Römpler  , Kubik-Huch
Published: August 2007

Wie die Empirie belegt, sinken mit steigender Arbeitszufriedenheit und -motivation die Fluktuations- und Absenzkosten in einem Betrieb. Den Mitarbeitenden ein motivierendes Betriebsklima zur Verfügung zu stellen, ist auch im Gesundheitswesen und damit im Fachgebiet Radiologie in zunehmendem Masse wichtig. Ziel dieser Arbeit war es deshalb, die aktuelle berufliche Zufriedenheit der Mitarbeitenden und die dafür wichtigen Einflussfaktoren zu evaluieren. Methodik: Zur Datenerhebung wurde ein standardisierter Fragebogen gewählt. Es wurden anhand von Befragungen in einer Fokusgruppe neun Indikatoren zur Charakterisierung der Arbeitszufriedenheit und -motivation festgelegt (vierstufige Ordinalskala), zusätzlich gab es die Möglichkeit von offenen Bemerkungen. Die Fragebogen wurden an alle im November 2005 anwesenden Mitarbeitenden am Institut (n = 50) für eine anonymisierte Datenerhebung verteilt. Für die statistische Auswertung wurden die Antworten codiert (Skala 1–4) und in eine Datenerfassungsmaske eingetragen. Resultate: Die Rücklaufquote betrug 92% (46 von 50). Im Allgemeinen schätzten die Befragten ihre Arbeitstätigkeit (3.37 ± 0.5), wobei kein statistisch signifikanter Unterschied zwischen Ärzten, MTRA und anderen nicht-ärztlichen Mitarbeitenden bestand. Als besonders motivierende Faktoren wurden ein gutes Betriebsklima (3.85 ± 0.4), ein guter Ruf der Abteilung (3.56 ± 0.8) und die berufliche Anerkennung genannt (3.54 ± 0.6). Gehaltserhöhungen (3.01 ± 0.9) und Zusatzleistungen wie Boni oder Prämien (3.11 ± 0.9) waren etwas weniger wichtig. Die Kommunikation zwischen den Arbeitsbereichen wurde insgesamt als relativ schlecht bewertet (2.78 ± 0.7). Bei der Frage, welche Faktoren die Arbeitsmotivation am meisten verbessern könnten, wurden insbesondere bessere Zusammenarbeit und Kommunikation (n = 9), vermehrte Einbindung in Entscheidungsprozesse (n = 8), berufliche Anerkennung (n = 7) und kontinuierliche Möglichkeit der fachlichen Weiterbildung (n = 5) genannt. Folgerung: Die genaue Kenntnis der Faktoren, die die Arbeitsmotivation und -zufriedenheit der Mitarbeitenden beeinflussen, erlaubt es gezielt entsprechende Verbesserungsmassnahmen einzuleiten.
Floppy Baby mit makrozytärer Anämie und veganischer Mutter
Authors: Schlapbach  , Schütz  , Nuoffer  , Brekenfeld  , Müller  , Fluri
Published: August 2007

Wir berichten über ein 7 Monate altes Mädchen, das sich mit einer hämolytischen Anämie, einer generalisierten muskulären Hypotonie sowie einer Gedeihstörung präsentierte. Als Ursache fand sich ein kongenitaler Vitamin-B12-Mangel bei veganischer Mutter. Die häufigste Ursache eines Vitamin-B12-Mangels im Säuglingsalter ist ein mütterlicher Cobalamin-Mangel. Dieser ist meist alimentär bedingt. Selten kann jedoch auch eine Stoffwechselstörung vorliegen. Die klinische Trias eines «acquired floppy baby syndrome», einer Gedeihstörung sowie einer makrozytären Anämie ist für das Vorliegen eines frühkindlichen Vitamin-B12-Mangels pathognomonisch. Die neurologischen Auffälligkeiten weisen als anatomisches Korrelat eine Myelinisierungsstörung auf und sind trotz Substitution teilweise irreversibel. Ein normaler Vitamin-B12-Spiegel und eine fehlende Anämie schliessen in der Schwangerschaft einen subklinischen Vitamin-B12-Mangel nicht aus; diagnostisch sind eine erhöhte Methylmalonsäure-Ausscheidung im Urin sowie erhöhte Homocysteinspiegel im Serum. Eine sorgfältige Ernährungsanamnese, ein grosszügiges Screening mittels Methylmalonsäure-Bestimmung im Urin und allenfalls eine Cobalamin-Substitution der Mutter können eine potentiell irreversible Schädigung des Feten verhindern.
Measurements of thermospheric molecular oxygen from the Solar Ultraviolet Spectral Irradiance Monitor
Authors: Lumpe J. D. , Floyd L. E. , Herring L. C. , Gibson S. T. , Lewis B. R.
Published: August 2007

We present a new data set of thermospheric O2 density profiles retrieved from solar occultation measurements made by the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) instrument on board the UARS satellite. SUSIM is nominally a solar experiment whose mission was to measure the magnitude and variability of the UV solar irradiance. However, it was also capable of remotely sensing the Earth's upper atmosphere using occultation. SUSIM measurements of solar attenuation in the O2 Schumann Runge continuum are used to retrieve O2 density profiles between 110 and 240 km. Between October 1991 and February 2005, SUSIM performed solar occultation measurements up to one day per week, measuring full‐disk solar extinction as a function of tangent altitude at three nominal wavelengths (144, 161 and 171 nm). These data have been inverted using an optimal estimation algorithm to produce altitude profiles of O2 density. This unique data set comprises approximately 1550 measurements, which span a wide range of solar and geomagnetic activity and latitudes up to 75° in each hemisphere. We present a discussion of the SUSIM instrument, the measurement technique employed for occultations, and the operational retrieval algorithm. A full error analysis and retrieval characterization study demonstrates that the SUSIM retrievals have uncertainties of 10–15% and a vertical resolution of 5–15 km, depending on altitude and measurement wavelength. The data thus have sufficient accuracy and resolution to provide scientifically useful constraints on the O2 abundance and variability, and initial comparisons show good overall agreement between the NRLMSIS‐00 model and the SUSIM measurements.
Diurnal cycle of precipitation in the NASA Seasonal to Interannual Prediction Project atmospheric general circulation model
Authors: Lee Myong‐In , Schubert Siegfried D. , Suarez Max J. , Bell Thomas L. , Kim Kyu‐Myong
Published: August 2007

The global statistics of the diurnal cycle of warm‐season precipitation simulated by NASA's Seasonal to Interannual Prediction Project (NASA/NSIPP) atmospheric general circulation model (AGCM) were evaluated using the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) rain retrievals. The model has notable biases in the phase of the diurnal cycle over land, where it produces rainfall maxima in the early afternoon, several hours earlier than the observed evening maxima. The model also produces too little precipitation in the nighttime over land. Similar biases in the phase were found over ocean, although the statistics are less robust. An analysis of the convective and stratiform contributions to the precipitation indicates that the incorrect representation of the diurnal cycle is primarily tied to deficiencies in the deep convection scheme. A set of sensitivity experiments shows that the phase of the maximum diurnal precipitation is quite sensitive to the change of the convection starting (parcel origination) level and the increase of the convection adjustment (relaxation) timescale in the Relaxed Arakawa‐Schubert scheme. Both modifications act to delay the timing for the maximum development of CAPE, which lead to improvements in the diurnal cycle of precipitation, especially in correcting the phase errors over land, although the modifications tend to reduce the diurnal amplitudes substantially. The study suggests that improvements to the diurnal cycle in current models require improvements to the parameterized deep convection schemes, including the coupling with the boundary layer, the characteristic timescale of convection adjustment, and the triggering process for nocturnal precipitation.
Effects of current–bed form induced fluid flow on the thermal regime of sediments
Authors: Cardenas M. Bayani , Wilson John L.
Published: August 2007

Heat transport associated with current–bed form fluid exchange affects biogeochemical and ecological process in a variety of aquatic settings. We simulate turbulent flow over dunes, induced Darcy flow in sediments, and sediment heat transport forced by a diel variation of water column temperature. Heat conduction dominates when the water column current cannot induce rapid fluid exchange. Heat advection becomes important with increasing sediment permeability and/or current velocity, resulting in a complicated space‐time temperature pattern. Weak temperature variations are found beneath dune crests, where water upwells out of the sediments; strong variations are located below dune stoss faces, where water downwells. The relative dominance of heat conduction versus advection is captured by a global Peclet number that depends on dune geometry, and hydrodynamic and thermal properties, including the period of thermal forcing. Thermally induced fluid viscosity variations cause periodic but nonsymmetric changes in fluid flux through the sediments, but do not significantly influence temperature patterns.
Entering into the “greenhouse century”: Recent record temperatures in Switzerland are comparable to the upper temperature quantiles in a greenhouse climate
Authors: Beniston Martin
Published: August 2007

This paper investigates the recent spate of record‐breaking warm seasons that have affected Switzerland in less than a decade and compares the seasonal statistics to those simulated for a “greenhouse‐gas” climate by the end of the 21st century. The peaks of minimum and maximum temperatures observed during some the record seasons enter well into the 25%–75% temperature quantile range for the scenario climate simulated by a set of regional climate models. The anomalously warm seasons allow a “preview” of conditions that may occur with greater frequency in the future. The use of current data as a form of proxy for the future enables an assessment of the possible impacts on the natural and socio‐economic environments, and can help in considering possible adaptation strategies to reduce some of the associated risks of climatic change.
Impact of a modified convective scheme on the Madden‐Julian Oscillation and El Niño–Southern Oscillation in a coupled climate model
Authors: Wu Xiaoqing , Deng Liping , Song Xiaoliang , Vettoretti Guido , Peltier W. Richard , Zhang Guang Jun
Published: August 2007

The connection between the intraseasonal Madden‐Julian Oscillation (MJO) and interannual El Niño–Southern Oscillation (ENSO) has been proposed and investigated for the last two decades. However, many fully coupled atmosphere‐ocean general circulation models (GCMs) are still unable to simulate many important characteristics of these two phenomena partly due to the great uncertainty in the representation of subgrid‐scale cloud systems. We report herein the simulation of an El Niño in a fully coupled GCM with a modified convection scheme, which captures many of the observed features of the 1997/1998 El Niño event. The representation of convection in the coupled model plays a major role in modeling both interannual ENSO and intraseasonal MJO variability in closer accord with observations, and in reproducing the evolution of 1997/1998 El Niño‐type events.
Protective Role of Reactive Astrocytes in Brain Ischemia
Authors: Li Lizhen , Lundkvist Andrea , Andersson Daniel , Wilhelmsson Ulrika , Nagai Nobuo , Pardo Andrea C , Nodin Christina , Ståhlberg Anders , Aprico Karina , Larsson Kerstin , Yabe Takeshi , Moons Lieve , Fotheringham Andrew , Davies Ioan , Carmeliet Peter , Schwartz Joan P , Pekna Marcela , Kubista Mikael , Blomstrand Fredrik , Maragakis Nicholas , Nilsson Michael , Pekny Milos
Published: August 2007

Reactive astrocytes are thought to protect the penumbra during brain ischemia, but direct evidence has been lacking due to the absence of suitable experimental models. Previously, we generated mice deficient in two intermediate filament (IF) proteins, glial fibrillary acidic protein (GFAP) and vimentin, whose upregulation is the hallmark of reactive astrocytes. GFAP−/−Vim−/− mice exhibit attenuated posttraumatic reactive gliosis, improved integration of neural grafts, and posttraumatic regeneration. Seven days after middle cerebral artery (MCA) transection, infarct volume was 210 to 350% higher in GFAP−/−Vim−/− than in wild-type (WT) mice; GFAP−/−, Vim−/− and WT mice had the same infarct volume. Endothelin B receptor (ETBR) immunoreactivity was strong on cultured astrocytes and reactive astrocytes around infarct in WT mice but undetectable in GFAP−/−Vim−/− astrocytes. In WT astrocytes, ETBR colocalized extensively with bundles of IFs. GFAP−/−Vim−/− astrocytes showed attenuated endothelin-3-induced blockage of gap junctions. Total and glutamate transporter-1 (GLT-1)-mediated glutamate transport was lower in GFAP−/−Vim−/− than in WT mice. DNA array analysis and quantitative real-time PCR showed downregulation of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of tissue plasminogen activator. Thus, reactive astrocytes have a protective role in brain ischemia, and the absence of astrocyte IFs is linked to changes in glutamate transport, ETBR-mediated control of gap junctions, and PAI-1 expression.
Role of the highly structured 5′-end region of MDR1 mRNA in P-glycoprotein expression
Authors: Randle Rebecca A. , Raguz Selina , Higgins Christopher F. , Yagüe Ernesto
Published: August 2007

Overexpression of P-glycoprotein, encoded by the MDR1 (multidrug resistance 1) gene, is often responsible for multidrug resistance in acute myeloid leukaemia. We have shown previously that MDR1 (P-glycoprotein) mRNA levels in K562 leukaemic cells exposed to cytotoxic drugs are up-regulated but P-glycoprotein expression is translationally blocked. In the present study we show that cytotoxic drugs down-regulate the Akt signalling pathway, leading to hypophosphorylation of the translational repressor 4E-BP [eIF (eukaryotic initiation factor) 4E-binding protein] and decreased eIF4E availability. The 5′-end of MDR1 mRNA adopts a highly-structured fold. Fusion of this structured 5′-region upstream of a reporter gene impeded its efficient translation, specifically under cytotoxic stress, by reducing its competitive ability for the translational machinery. The effect of cytotoxic stress could be mimicked in vivo by blocking the phosphorylation of 4E-BP by mTOR (mammalian target of rapamycin) using rapamycin or eIF4E siRNA (small interfering RNA), and relieved by overexpression of either eIF4E or constitutively-active Akt. Upon drug exposure MDR1 mRNA was up-regulated, apparently stochastically, in a small proportion of cells. Only in these cells could MDR1 mRNA compete successfully for the reduced amounts of eIF4E and translate P-glycoprotein. Consequent drug efflux and restoration of eIF4E availability results in a feed-forward relief from stress-induced translational repression and to the acquisition of drug resistance.
The EWS–Oct-4 fusion gene encodes a transforming gene
Authors: Lee Jungwoon , Kim Ja Young , Kang In Young , Kim Hye Kyoung , Han Yong-Mahn , Kim Jungho
Published: August 2007

The t(6;22)(p21;q12) translocation associated with human bone and soft-tissue tumours results in a chimaeric molecule fusing the NTD (N-terminal domain) of the EWS (Ewing's sarcoma) gene to the CTD (C-terminal domain) of the Oct-4 (octamer-4) embryonic gene. Since the N-terminal domains of EWS and Oct-4 are structurally different, in the present study we have assessed the functional consequences of the EWS–Oct-4 fusion. We find that this chimaeric gene encodes a nuclear protein which binds DNA with the same sequence specificity as the parental Oct-4 protein. Comparison of the transactivation properties of EWS–Oct-4 and Oct-4 indicates that the former has higher transactivation activity for a known target reporter gene containing Oct-4 binding. Deletion analysis of the functional domains of EWS–Oct-4 indicates that the EWS (NTD), the POU domain and the CTD of EWS–Oct-4 are necessary for full transactivation potential. EWS–Oct-4 induced the expression of fgf-4 (fibroblast growth factor 4) and nanog, which are potent mitogens as well as Oct-4 downstream target genes whose promoters contain potential Oct-4-binding sites. Finally, ectopic expression of EWS–Oct-4 in Oct-4-null ZHBTc4 ES (embryonic stem) cells resulted in increased tumorigenic growth potential in nude mice. These results suggest that the oncogenic effect of the t(6;22) translocation is due to the EWS–Oct-4 chimaeric protein and that fusion of the EWS NTD to the Oct-4 DNA-binding domain produces a transforming chimaeric product.
The Arabidopsis ALDP protein homologue COMATOSE is instrumental in peroxisomal acetate metabolism
Authors: Hooks Mark A. , Turner James E. , Murphy Elaine C. , Johnston Katherine A. , Burr Sally , Jarosławski Szymon
Published: August 2007

The Arabidopsis acn (acetate non-utilizing) mutants were isolated by fluoroacetate-resistant germination and seedling establishment. We report the characterization of the acn2 mutant. Physiological analyses of acn2 showed that it possessed characteristics similar to those of the mutants cts (COMATOSE)-1 and pxa [peroxisomal ABC (ATP-binding-cassette) transporter]1. The acn2 locus was mapped to within 3 cM of the CTS gene on the bottom arm of chromosome IV using CAPS (cleavage amplification polymorphism) and SSLP (simple sequence-length polymorphism) markers. Crossing acn2 and cts-1 failed to restore the fluoroacetate-sensitive phenotype, suggesting that these mutations were allelic. Sequencing of the ACN2 locus revealed a C→T nonsense mutation in exon 13, which would have resulted in the elimination of the C-terminal hemitransporter domain of the encoded protein. Neither the full-length CTS protein nor the truncated protein was detected on immunoblots using either C-terminal- or N-terminal-specific anti-CTS antibodies respectively, demonstrating the absence of the entire CTS protein in acn2 mutants. Emerged seedlings of both cts-1 and pxa1 alleles displayed increased resistance to FAc (monofluoroacetic acid) compared with the corresponding wild-type seedlings. Complementation studies showed that mutation of the CTS gene was responsible for the FAc-resistant phenotype, as when the wild-type protein was expressed in both the cts-1 and pxa1 mutant lines, the strains became FAc-sensitive. Feeding studies confirmed that both acn2 and cts-1 mutants were compromised in their ability to convert radiolabelled acetate into soluble carbohydrate. These results demonstrate a role for the ABC protein CTS in providing acetate to the glyoxylate cycle in developing seedlings.
S-Adenosyl-L-methionine:magnesium-protoporphyrin IX O-methyltransferase from Rhodobacter capsulatus: mechanistic insights and stimulation with phospholipids
Authors: Sawicki Artur , Willows Robert D.
Published: August 2007

The enzyme BchM (S-adenosyl-L-methionine:magnesium-protoporphyrin IX O-methyltransferase) from Rhodobacter capsulatus catalyses an intermediate reaction in the bacteriochlorophyll biosynthetic pathway. Overexpression of His6-tagged protein in Escherichia coli resulted in the majority of polypeptide existing as inclusion bodies. Purification from inclusion bodies was performed using metal-affinity chromatography after an elaborate wash step involving surfactant polysorbate-20. Initial enzymatic assays involved an in situ generation of S-adenosyl-L-methionine substrate using a crude preparation of S-adenosyl-L-methionine synthetase and this resulted in higher enzymatic activity compared with commercial S-adenosyl-L-methionine. A heat-stable stimulatory component present in the S-adenosyl-L-methionine synthetase was found to be a phospholipid, which increased enzymatic activity 3–4-fold. Purified phospholipids also stabilized enzymatic activity and caused a disaggregation of the protein to lower molecular mass forms, which ranged from monomeric to multimeric species as determined by size-exclusion chromatography. There was no stimulatory effect observed with magnesium–chelatase subunits on methyltransferase activity using His–BchM that had been stabilized with phospholipids. Substrate specificity of the enzyme was limited to 5-co-ordinate square-pyramidal metalloporphyrins, with magnesium-protoporphyrin IX being the superior substrate followed by zinc-protoporphyrin IX and magnesium-deuteroporphyrin. Kinetic analysis indicated a random sequential reaction mechanism. Three non-substrate metalloporphyrins acted as inhibitors with different modes of inhibition exhibited with manganese III-protoporphyrin IX (non-competitive or uncompetitive) compared with cobalt II-protoporphyrin IX (competitive).
Western diet, but not high fat diet, causes derangements of fatty acid metabolism and contractile dysfunction in the heart of Wistar rats
Authors: Wilson Christopher R. , Tran Mai K. , Salazar Katrina L. , Young Martin E. , Taegtmeyer Heinrich
Published: August 2007

Obesity and diabetes are associated with increased fatty acid availability in excess of muscle fatty acid oxidation capacity. This mismatch is implicated in the pathogenesis of cardiac contractile dysfunction and also in the development of skeletal-muscle insulin resistance. We tested the hypothesis that ‘Western’ and high fat diets differentially cause maladaptation of cardiac- and skeletal-muscle fatty acid oxidation, resulting in cardiac contractile dysfunction. Wistar rats were fed on low fat, ‘Western’ or high fat (10, 45 or 60% calories from fat respectively) diet for acute (1 day to 1 week), short (4–8 weeks), intermediate (16–24 weeks) or long (32–48 weeks) term. Oleate oxidation in heart muscle ex vivo increased with high fat diet at all time points investigated. In contrast, cardiac oleate oxidation increased with Western diet in the acute, short and intermediate term, but not in the long term. Consistent with fatty acid oxidation maladaptation, cardiac power decreased with long-term Western diet only. In contrast, soleus muscle oleate oxidation (ex vivo) increased only in the acute and short term with either Western or high fat feeding. Fatty acid-responsive genes, including PDHK4 (pyruvate dehydrogenase kinase 4) and CTE1 (cytosolic thioesterase 1), increased in heart and soleus muscle to a greater extent with feeding a high fat diet compared with a Western diet. In conclusion, we implicate inadequate induction of a cassette of fatty acid-responsive genes, and impaired activation of fatty acid oxidation, in the development of cardiac dysfunction with Western diet.