bluuebunny/crossref_metadata_2025 huggingface dataset:
System efficiency of a DC/DC converter‐based wind farm
Authors: Max Lena , Lundberg Stefan
Published: October 2007

In this paper, three DC/DC converter topologies are evaluated from an energy efficiency point of view regarding their suitability for the application in a DC wind farm grid. The three investigated topologies are the fullbridge (FB) converter, the single active bridge (SAB) converter and the series parallel resonant (LCC) converter. The energy efficiency of the three converter topologies is evaluated for different control strategies. It is found that the LCC and FB converters have the lowest losses of the three topologies. It is also shown that the wide range of operation creates problems for all three converters. The SAB converter has the largest increase in losses caused by the wide range of operation. The FB converter also has an increase in losses for this variable operating range, whereas the LCC converter has large stresses for the input and output filters. By considering some further factors, such as the contribution to the energy production cost, the design and the control of the converters, the FB converter is found to be a suitable choice for wind farm application. Copyright © 2007 John Wiley & Sons, Ltd.
A Saccharomyces cerevisiae cell‐based quantitative β‐galactosidase assay compatible with robotic handling and high‐throughput screening
Authors: de Almeida Rogerio Alves , Burgess Danielle , Shema Reut , Motlekar Nuzhat , Napper Andrew D. , Diamond Scott L. , Pavitt Graham D.
Published: October 2007

Reporter‐gene assays that employ the Escherichia coli lacZ gene are ubiquitously employed in biological research. However, we were not able to readily identify a quantitative method that worked reliably with yeast (Saccharomyces cerevisiae) cells and that was compatible with high‐throughput screening and robotic liquid handling tools. We have therefore adapted a commercially available assay employing a 6‐O‐β‐galactopyranosyl–luciferin substrate to provide the required sensitivity with minimal sample handling times. Our assay uses only one‐tenth of the reagents suggested by the reagent manufacturer (Promega) for equivalent assays with mammalian cell cultures and produces rapid, sensitive and reproducible analysis with as little as 1 µl yeast cell culture and with < 100 cells. We demonstrate that the assay is compatible with yeast strains generated by the systematic yeast deletion project and functions equally well with genomically integrated or plasmid‐encoded lacZ reporters and with cells grown in complex or defined media. The high‐sensitivity, miniaturized format reduced sample handling required will make this assay useful for a wide range of applications. Copyright © 2007 John Wiley & Sons, Ltd.
Benefit of Ultrasonography in the Detection of Clinically and Mammographically Occult Breast Cancer
Authors: Chan Sharon W. W. , Cheung Polly S. Y. , Chan Stefanie , Lau Suk Sze , Wong Ting Ting , Ma Michael , Wong Ada , Law Yuen Ching
Published: October 2007

Objective

The purpose of this study was to evaluate the performance of high‐resolution ultrasonography in the detection of clinically and mammographically occult breast cancer.

Materials and methods

From September 2003 to November 2006, a total of 1485 patients were confirmed to have in situ or invasive breast cancer in Hong Kong Sanatorium and Hospital Breast Care Centre. All patients underwent mammography (MMG) and/ or sonography (USG) evaluation. Patients’ age and size of tumor detected by USG alone were compared with those detected by MMG.

Results

Altogether, 222 patients (17%) had positive imaging findings on USG only, among which 22 (13%) patients had nonpalpable tumors. Performing USG increased the cancer detection rate among clinically and mammographically occult breast lesions by 14.3%. The mean size of the tumors detected only by USG was 1.98 cm, which was not significantly different from the mean size of tumor detected by MMG (1.46) (p = 0.23). This remains true in the group of patients with nonpalpable tumors (1.36 vs. 1.46 cm, p = 0.88). The sensitivity of USG is 91%, which is significantly higher than that of MMG (78%) (p = 0.001). This remains true in patients age <40 or ≥40, tumor grading I toIII, and LVI +/− cases. However, MMG had higher sensitivity in the group of patients with nonpalpable tumors (73% vs. 62%, p = 0.01) and noninvasive cancers (72% vs. 69%, p = 0.01).

Conclusions

The use of high‐resolution USG may lead to detection of a significant number of occult cancers that are no different in size from nonpalpable mammographically detected lesions.
Hypolipidemic and Antioxidant Effects of Dietary Curcumin and Capsaicin in Induced Hypercholesterolemic Rats
Authors: Manjunatha H. , Srinivasan K.
Published: October 2007

Health beneficial hypolipidemic and antioxidant influences of dietary spice principles—curcumin, capsaicin alone and in combination included in the diet for 8 weeks were evaluated in induced hypercholesterolemic rats, in order to verify if there is any additive or synergistic effect of these two bioactive compounds. Dietary curcumin (0.2%), capsaicin (0.015%) or their combination significantly countered the hypercholesterolemia brought about by high cholesterol feeding. Hepatic cholesterol was lowered by dietary spice principles only in normal rats. Liver triglyceride levels were lowered in both normal and hypercholesterolemic rats by capsaicin. Curcumin and capsaicin lowered hepatic and blood lipid peroxides in hypercholesterolemic rats, while the effect in blood was additive with their combination. Hepatic ascorbic acid was enhanced by dietary spice principles in normal rats; glutathione was enhanced by their combination only in hypercholesterolemic rats. Activities of serum glutathione reductase, glutathione transferase and catalase and hepatic glutathione reductase in normal rats and serum glutathione peroxidase in hypercholesterolemic rats were enhanced by dietary spice principles. While dietary curcumin and capsaicin normalized the changes in the levels of antioxidant molecules and activities of antioxidant enzymes to a significant extent, this effect was not generally additive when given in combination, and was higher than the individual effects only in a few instances.
Contribution of IL‐12R mediated feedback loop to Th1 cell differentiation
Authors: Becskei Attila , Grusby Michael J.
Published: October 2007

T helper 1 (Th1) cell fate is induced by overlapping signaling pathways, whose kinetic principles and regulatory motifs are largely unknown. We identified a simple positive feedback loop in the STAT4 signaling pathway, whereby activation by IL‐12 leads to the increased expression in IL‐12 receptor. A computational analysis shows that this feedback loop synergizes with the one mediated by the IFN‐γ secreted by differentiating cells, when the induction of Th1 cell fate is weak. Positive feedback loops are often utilized to enhance phenotypic differentiation. This effect was confirmed by experiments showing that stochastic fluctuations in the expression of IL‐12 receptor gene were amplified, leading to two discrete levels of expression in a cell population.
Kinetic characterization of mammalian ceramide synthases: Determination of Km values towards sphinganine
Authors: Lahiri Sujoy , Lee Hyunmi , Mesicek Judith , Fuks Zvi , Haimovitz-Friedman Adriana , Kolesnick Richard N. , Futerman Anthony H.
Published: October 2007

Ceramide is a key metabolite in the pathway of sphingolipid biosynthesis. In mammals, ceramide is synthesized by N‐acylation of a sphingoid long‐chain base by a family of ceramide synthases (CerS), each of which displays a high specificity towards acyl CoAs of different chain lengths. We now optimize a previously‐described assay for measuring CerS activity for use upon over‐expression of mammalian CerS, and using these conditions, establish the K
m value of each CerS towards sphinganine. Remarkably, the K
m values towards sphinganine are all similar, ranging from 2 to 5 μM, even for CerS proteins that are able to use more than one acyl CoA for ceramide synthesis (i.e. CerS4). The availability of this assay will permit further accurate characterization of the kinetic parameters of mammalian CerS proteins.
Ambient particulate matter induces alveolar epithelial cell cycle arrest: Role of G1 cyclins
Authors: Zhang Jingmei , Ghio Andrew J. , Gao Mingxing , Wei Ke , Rosen Glenn D. , Upadhyay Daya
Published: October 2007

We hypothesized that the ambient air pollution particles (particulate matter; PM) induce cell cycle arrest in alveolar epithelial cells (AEC). Exposure of PM (25 μg/cm2) to AEC induced cells cycle arrest in G1 phase, inhibited DNA synthesis, blocked cell proliferation and caused decrease in cyclin E, A, D1 and Cyclin E‐ cyclin‐dependent kinase (CDK)‐2 kinase activity after 4 h. PM induced upregulation of CDK inhibitor, p21 protein and p21 activity in AEC. SiRNAp21 blocked PM‐induced downregulation of cyclins and AEC G1 arrest. Accordingly, we provide the evidence that PM induces AEC G1 arrest by altered regulation of G1 cyclins and CDKs.
TGF‐β suppresses POEM expression through ERK1/2 and JNK in osteoblasts
Authors: Miyazono Agasa , Yamada Atsushi , Morimura Naoko , Takami Masamichi , Suzuki Dai , Kobayashi Makoto , Tezuka Ken-ichi , Yamamoto Matsuo , Kamijo Ryutaro
Published: October 2007

POEM, also called nephronectin, is an extracellular matrix protein that is considered to play a critical role as an adhesion molecule in the development and functioning of various tissues, such as kidneys and bones. In the present study, we examined the molecular mechanism of POEM gene expression, and found that transforming growth factor‐β (TGF‐β) strongly inhibited POEM expression in the mouse osteoblastic cell line, MC3T3‐E1. TGF‐β‐induced decrease of POEM expression occurred in both time‐ and dose‐dependent manners through the activation of TGF‐β receptor I and extracellular signal‐regulated kinase/c‐Jun N‐terminal kinase pathways.
“It Reads Like a Novel”: The 9/11 Commission Report and the American Reading Public
Authors: WARREN CRAIG A.
Published: October 2007

When published in July 2004, the 9/11 Commission Report surprised readers with its accessible prose and narrative power. The report won the respect of the American public as much for its literary qualities as for the findings of the 9/11 commissioners. This article argues that the success of the 9/11 Report depended on its ability to challenge literary classification, and to bring down the walls between personal and national experience. More effectively than any other literary work of its era, the 9/11 Report wed the fortunes of a weakened American government to those of a wounded citizenry.
On Cowboys and Welfare Queens: Independence, Dependence, and Interdependence at Home and Abroad
Authors: BORIS EILEEN
Published: October 2007

Against a historiography that too often considers domestic policy apart from foreign policy, this essay suggests connections based on two cultural/political archetypes, the cowboy and the welfare queen, which were or are simultaneously gendered and racialized. The cowboy as a symbol of white male individualism has represented worthy American manhood; the welfare queen has stood for a despised black womanhood. Behind the image of the cowboy stands the workings of empire; behind the portrait of the welfare queen lies the punishment of poor women, often African American or Latina, for their motherhood, sexuality, and lack of dependence on husbands. The problem with the welfare queen is that she parlayed her dependence on the state into independence from men and employment (that is, work as commonly understood.) Like the enemies without, who would make the nation dependent through withholding a vital resource – oil – and require disciplining through “cowboy diplomacy,” welfare dependents have become the primitive other, politically assaulted, responsible for national decline, who need taming through cowboy social policy. Drawing upon newspaper accounts, blogs, speeches, and iconographic representations, this essay traces the ways that modern Presidents, including Theodore Roosevelt, Johnson, Nixon, Reagan, and Bush II, deployed these icons to push independence as a national virtue in spite of their apparently different political positions. The languages of independence and dependence provided an easy vocabulary for policymaking that aspires to moral heights, leading to a performativity that traps those who utter the tropes of their predecessors into policy grooves not necessarily of their own choosing.
PREVALENCE OF AND RISK FACTORS ASSOCIATED WITH ALCOHOL ABUSE IN MOSHI, NORTHERN TANZANIA
Authors: MITSUNAGA TISHA , LARSEN ULLA
Published: October 2007

This study aimed to assess the prevalence of and risk factors associated with alcohol abuse among women and men in Moshi in northern Tanzania. Alcohol abuse was measured by a CAGE score of 2–4, versus 0–1 for no alcohol abuse (Ewing, 1984). Crude and adjusted logistic regression models determined odds ratios (OR) and 95% confidence intervals (95% CI) of alcohol abuse by characteristics of, respectively, women with partners (n=1200), women without partners (n=614) and men (n=788) (women’s partners). Prevalence of alcohol abuse was 7·0% (95% CI: 5·6–8·4) among women with partners, 9·3% (95% CI: 7·0–11·6) among women without partners, and more than double among men at 22·8% (95% CI: 19·9–25·8). In general, Christians had higher alcohol abuse than Muslims or other religions, as did Chagga men compared with men of other ethnic groups. Other socio-demographic characteristics, such as education or income, were not significant. Sexual behaviours were significant predictors of alcohol abuse. For example, women without partners who reported more than two partners in the last year had higher alcohol abuse compared with women reporting no partners (OR=8·75; 95% CI: 2·37–32·31), as did men reporting it is ‘OK to hit a partner’ for any reason (OR=1·79; 95% CI: 1·16–2·77) compared with men who did not. HIV-1 infection was not significantly associated with alcohol abuse by women or men. The Christian Church in Moshi should consider raising awareness about the harmful effects of high alcohol use among its adherents. Comprehensive programmes focusing on reducing number of partners and alcohol use, particularly by men, are needed in this community.
ASSOCIATION BETWEEN AGE AT MENARCHE AND EARLY-LIFE NUTRITIONAL STATUS IN RURAL BANGLADESH
Authors: BOSCH ALINDA M. , WILLEKENS FRANS J. , BAQUI ABDULLAH H. , VAN GINNEKEN JEROEN K. S. , HUTTER INGE
Published: October 2007

Age at menarche is associated with anthropometry in adolescence. Recently, there has been growing support for the hypothesis that timing of menarche may be set early in life but modified by changes in body size and composition in childhood. To evaluate this, a cohort of 255 girls aged <5 years recruited in 1988 were followed up in 2001 in Matlab, Bangladesh. The analysis was based on nutritional status as assessed by anthropometry and recalled age at menarche. Data were examined using lifetable techniques and the Cox regression model. The association between nutritional status indicators and age at menarche was examined in a multivariate model adjusting for potential confounding variables. Censored cases were accounted for. The median age at menarche was 15·1 years. After controlling for early-life predictors (birth size, childhood underweight, childhood stunting) it appeared that adolescent stunting stood out as the most important determinant of age at menarche. Adolescent stunting still resonates from the effect of stunting in early childhood (OR respectively 2·63 (p<0·01 CI: 1·32–5·24) and 8·47 (p<0·001 CI: 3·79–18·93) for moderately and severely stunted under-fives as compared with the reference category). Birth size was not a significant predictor of age at menarche. It is concluded that age at menarche is strongly influenced by nutritional status in adolescence, notably the level of stunting, which is in turn highly dependent on the level of stunting in early childhood. A ‘late’ menarche due to stunting may be detrimental for reproductive health in case of early childbearing because of the association between height and pelvic size.
Light and confocal microscopic observations of adultSchistosoma mansonifrom mice fed on a high-fat diet
Authors: Neves Renata H. , Alencar Alba C.M.B. , Águila Marcia B. , Mandarim-de-Lacerda Carlos A. , Machado- Silva José R. , Gomes Delir C.
Published: October 2007

The morphological aspects ofSchistosoma mansoniadult worms recovered from albino mice fed on a cholesterol-rich diet compared to mice fed on a standard chow were investigated. After feeding on their respective diets for over a period of 5 months, mice were subcutaneously infected withc. 50S. mansonicercariae/mouse. Blood samples were obtained 1 day prior to experimental infections and 63 days later, when mice were euthanized by jugular section (hypovolaemic shock). Total cholesterol (TC) levels were determined. Recovered worms were stained with hydrochloric carmine, and preserved as whole-mounts for examination by bright-field and laser confocal microscopy. The infected mice fed on high-fat chow showed higher levels of serum lipoproteins than the infected mice fed on standard chow, except for very-low-density lipoprotein cholesterol (VLDL-c) and triglycerides (TG). In this experiment, worms from mice fed on a high-fat chow showed a greater percentage of morphological differentiation regarding supernumerary testes, seminal vesicle, and seminal receptacle. In mice of this group, the rate of oocyte laying in the ovary was much higher than in control females. The present results suggest that cholesterol could be actively involved in the modulation of cell signalling and reproduction, because the lobes contained fully developed oocytes in variable amounts, different from control males. The data presented here are the first to report the role of a cholesterol-rich diet affecting the development ofS. mansoniworms.
Two-year-olds differentially disambiguate novel words and facts
Authors: SCOFIELD JASON , BEHREND DOUGLAS A.
Published: October 2007

When presented with a pair of objects, one familiar and one unfamiliar, and asked to select the referent of a novel word, children reliably demonstrate the disambiguation effect and select the unfamiliar object. The current study investigated two competing word learning accounts of this effect: a pragmatic account and a word learning principles account. Two-, three- and four-year-olds were presented with four disambiguation conditions, a word/word, a word/fact, a fact/word and a fact/fact condition. A pragmatic account predicted disambiguation in all four conditions while a word learning principles account predicted disambiguation in the word/word and fact/word conditions. Results indicated that children disambiguated in word/word and fact/word conditions and two-year-olds disambiguated at above chance levels in the word/word condition but at below chance levels in the fact/fact condition. Because disambiguation varied both as a function of age and condition these findings are presented as challenges to a pragmatic account of the disambiguation effect.
Nodal inequalities on surfaces
Authors: POLTEROVICH LEONID , SODIN MIKHAIL
Published: October 2007

Given a Laplace eigenfunction on a surface, we study the distribution of its extrema on the nodal domains. It is classically known that the absolute value of the eigenfunction is asymptotically bounded by the 4th root of the eigenvalue. It turns out that the number of nodal domains where the eigenfunction has an extremum of such order, remains bounded as the eigenvalue tends to infinity. We also observe that certain restrictions on the distribution of nodal extrema and a version of the Courant nodal domain theorem are valid for a rather wide class of functions on surfaces. These restrictions follow from a bound in the spirit of Kronrod and Yomdin on the average number of connected components of level sets.
Klein slopes on hyperbolic 3-manifolds
Authors: MATIGNON DANIEL , SAYARI NABIL
Published: October 2007

This paper is devoted to 3-manifolds which admit two distinct Dehn fillings producing a Klein bottle.

LetMbe a compact, connected and orientable 3-manifold whose boundary contains a 2-torusT. IfMis hyperbolic then only finitely many Dehn fillings alongTyield non-hyperbolic manifolds. We consider the situation where two distinct slopes γ1, γ2produce a Klein bottle. We give an upper bound for the distance Δ(γ1, γ2), between γ1and γ2. We show that there are exactly four hyperbolic manifolds for which Δ(γ1, γ2) > 4.
Unital Banach algebras and their subalgebras
Authors: MIAO TIANXUAN
Published: October 2007

Let A be a Banach algebra with a bounded approximate identity. We prove that if A is not unital, then there is a nonunital subalgebra B of A with a sequential bounded approximate identity. It follows that A must be unital if A is weakly sequentially complete and B** under the first Arens multiplication has a unique right identity for every subalgebra B of A with a sequential bounded approximate identity. As a consequence, we prove a result of Ülger that if A is both weakly sequentially complete and Arens regular, then A must be unital.
The loop problem for monoids and semigroups
Authors: KAMBITES MARK
Published: October 2007

We propose a way of associating to each finitely generated monoid or semigroup a formal language, called itsloop problem. In the case of a group, the loop problem is essentially the same as theword problemin the sense of combinatorial group theory. Like the word problem for groups, the loop problem is regular if and only if the monoid is finite. We also study the case in which the loop problem iscontext-free, showing that a celebrated group-theoretic result of Muller and Schupp extends to describe completely simple semigroups with context-free loop problems. We consider right cancellative monoids, establishing connections between the loop problem and the structural theory of these semigroups by showing that the syntactic monoid of the loop problem is theinverse hullof the monoid.
Parvovirus B19 infection in five European countries: seroepidemiology, force of infection and maternal risk of infection
Authors: MOSSONG J. , HENS N. , FRIEDERICHS V. , DAVIDKIN I. , BROMAN M. , LITWINSKA B. , SIENNICKA J. , TRZCINSKA A. , VAN DAMME P. , BEUTELS P. , VYSE A. , SHKEDY Z. , AERTS M. , MASSARI M. , GABUTTI G.
Published: October 2007

We conducted a seroprevalence survey in Belgium, Finland, England & Wales, Italy and Poland on 13 449 serum samples broadly representative in terms of geography and age. Samples were tested for the presence of immunoglobulin G antibody using an enzyme immunoassay. The age-specific risk of infection was estimated using parametric and non-parametric statistical modelling. The age-specific risk in all five countries was highest in children aged 7–9 years and lower in adults. The average proportion of women of child-bearing age susceptible to parvovirus B19 infection and the risk of a pregnant women acquiring B19 infection during pregnancy was estimated to be 26% and 0·61% in Belgium, 38% and 0·69% in England & Wales, 43·5% and 1·24% in Finland, 39·9% and 0·92% in Italy and 36·8% and 1·58% in Poland, respectively. Our study indicates substantial epidemiological differences in Europe regarding parvovirus B19 infection.
Vikings in the Persian Gulf
Authors: Isitt Guy F.
Published: October 2007

This analysis of certain rock carvings at Jabal Jusasiyah Qatar is in the form of an Archaeological Report, but is not a full Archaeological Survey. This has been carried out by others – (Hans Kapel Arryan, Qatar National Museum Journal, 1983, pp. 1–126) for Jabal Jusasiyah Qatar. A systematic procedure is adopted for the analysis of a number of these petroglyphs at the sites in Qatar.
Stealing a Willing Bride: Women's Agency in the Myth of Rukmiṇī's Elopement
Authors: Pauwels Heidi
Published: October 2007

‘Krishna and Rukmini’ is the title of Amar Citra Kathā comic vol. 516, with artwork by Pratap Mulick. The front page has a muscular Kṛ⋅ṇa gallantly helping an entranced lady mount his chariot. Or is he that gallant? A closer look reveals that Kṛ⋅ṇa is actually grabbing her by the wrist; yet the lady seems more than willing, she is coquettishly lifting her skirt as she mounts the vehicle, and her eyes look adoringly, somewhat naively, at her hero as she smiles coyly. The only hint of opposition is in the background where we see angry mustached warriors coming after them. Is this a case of abduction, or is it better called an elopement?
Public Health – die Rolle der Hausärzte im Pandemiefall
Authors: Koch  , Witschi
Published: October 2007

Zusätzlich zum Schweizerischen Pandemieplan 2006 [1] wurden kürzlich die spezifischen Aufgaben der Grundversorger in der Schweiz im Pandemiefall publiziert [2]. Die gute Vorbereitung der Grundversorger für den Pandemiefall ist äußerst wichtig, sowohl wegen der zusätzlich anfallenden Erkrankungsfälle, als auch wegen der Erfahrung und Kompetenz der Hausärztinnen und Hausärzte in der Erkennung und Behandlung von Grippekranken. Dieser Artikel soll die Bedeutung der ärztlichen Grundversorgung im Dienste der öffentlichen Gesundheit unterstreichen und die Hausärztinnen und -ärzte in ihrer Vorbereitung auf eine mögliche Pandemie unterstützen.
Aviäre Influenza – die Sicht der Veterinärmedizin
Authors: Griot  , Hoop
Published: October 2007

Das natürliche Reservoir für sämtliche Influenza-A-Viren (AIV) bilden freilebende Wasser- und Küstenvögel. Hochpathogene AIV vom Subtyp H5 oder H7 haben seit geraumer Zeit immer wieder Geflügelpestausbrüche bei Nutzgeflügel verursacht. Neu ist die Tatsache, dass der Subtyp H5N1 ein zoonotisches Potenzial hat und andere Tierarten wie Katzen, Hunde und Marderartige infizieren kann. Lebendgeflügelmärkte und ungenügende Hygienemaßnahmen in Nutzgeflügelhaltungen sind mehrheitlich für die Verbreitung des hochpathogenen AIV Subtyp H5N1 in Asien und anderen Ländern verantwortlich. Zur Bekämpfung der Geflügelpest werden in asiatischen Ländern Impfstoffe eingesetzt; allerdings mit einem eher bescheidenen Erfolg. Zugvögel haben das H5N1-Virus erstmals im Herbst 2005 nach Westeuropa eingeschleppt. Daraus resultierte in ganz Europa ein Wildvogelüberwachungsprogramm, mit dem Ziel möglichst rasch ein Eintrag von AIV feststellen zu können. Internationale Organisationen wie das Tierseuchenamt OIE in Paris und die Welternährungsorganisation FAO in Rom werden auch in Zukunft gefordert sein, eine aktive Rolle in der Bekämpfung in den betroffenen Ländern zu übernehmen.
Bewältigung der Pandemie in der Praxis – muss ich mich, bzw. kann ich mich vorbereiten?
Authors: Ruef
Published: October 2007

Experten und nationale bzw. internationale Gesundheitsbehörden sind sich einig, dass mit dem Auftreten einer Grippepandemie in der näheren Zukunft zu rechnen ist. Da die überwiegende Mehrheit der Patienten ambulant behandelt werden muss, spielen die niedergelassenen praktizierenden Ärzte bei der Bewältigung der Grippepandemie auch in der Schweiz eine zentrale Rolle. Es wird notwendig sein, während der Pandemie die Patienten mit grippalen Symptomen auf standardisierte Weise zu diagnostizieren und zu therapieren. Der Pandemieplan des Bundesamtes für Gesundheit liefert dazu wichtige Hinweise. Neben der standardisierten klinischen Betreuung der Patienten kommt der Umsetzung von Hygienemaßnahmen in der Praxis ebenfalls eine große Bedeutung zu. Es geht darum, Patienten mit anderen Krankheiten vor Ansteckung zu schützen. Ebenfalls geschützt werden muss das Praxispersonal sowie natürlich der Praxisinhaber selbst. Die Schutzvorkehrungen umfassen einerseits die prophylaktische Einnahme von Oseltamivir während der Dauer der Pandemie, andererseits das Tragen geeigneter Schutzmasken zur Prävention der Tröpfchenübertragung während Patientenkontakt sowie der gezielte Einsatz von Desinfektionsmaßnahmen zur Verhinderung der Kontaktübertragung der Grippeviren in der Praxis. Damit die klinischen Aspekte und auch die Praxishygieneaspekte während der hektischen Zeit der Pandemie gut umgesetzt werden können, sind entsprechende Vorbereitungsarbeiten bereits jetzt sinnvoll.
Influenza im Kindesalter – ein epidemiologisches Problem
Authors: Heininger
Published: October 2007

Die Influenza (Grippe) ist eine akute virale Infektionskrankheit der Atemwege, die alle Altersgruppen betrifft und jährlich im Winter epidemische Ausmaße annimmt. Die akuten Symptome wie auch die hohe Rate an Komplikationen (meist sekundäre bakterielle Infektionen) bedingen die bereits im Kindesalter bedeutsame Morbidität. Hinzu kommt, dass offenbar insbesondere Kinder zu Beginn der Winterepidemien erkranken, das Virus in Gemeinschaftseinrichtungen effektiv verbreiten, und schließlich sekundär im eigenen familiären Umfeld streuen. Diese Merkmale der Influenza im Kindesalter lassen eine Erweiterung (generelle Impfempfehlung) der momentan auf bestimmte Risikogruppen fokusierten Impfstrategie sinnvoll erscheinen. Die Notwendigkeit der jährlich wiederholten Impfung wie auch die mangelnde Akzeptanz in der Bevölkerung stellen momentan dafür jedoch gravierende Hindernisse dar.
Grippeimpfung heute und morgen
Authors: Eich
Published: October 2007

Die Grippeimpfung verhindert bis zu 90% der Influenzainfektion bei gesunden Erwachsenen unter 65 Jahren, aber kaum bei Älteren und bei solchen mit einer Grunderkrankung. Diese Personengruppen werden jedoch signifikant vor den Komplikationen einer Infektion geschützt. Aus diesem Grund sind sie auch die Hauptzielgruppe der Impfempfehlung. Medizinalpersonen sollen wegen ihrem engen Kontakt zu Risikopersonen geimpft werden, doch werden hier nur sehr tiefe Impfraten erreicht. Seit 2005 ist die Impfung auch für Personen vorgesehen, die beruflich Kontakt zu Geflügel oder Wildvögel haben. Die Grippeimpfstoffe gelten als sehr sicher: Nebenwirkungen sind meist banal und innerhalb von ein bis zwei Tagen reversibel, schwere Komplikationen sind äußerst selten. Während in den USA auch eine attenuierter Lebendimpfstoff zur Verfügung steht, werden in Europa nur inaktivierte Impfstoffe verwendet. Sie enthalten die Oberflächenantigene von zwei Influenza A und einem Influenza B Virus. Die entsprechenden Viren werden jährlich von der WHO ausgewählt und in befruchteten Hühnereiern gezüchtet. Dieser Prozess ist langwierig und störungsanfällig. Vor allem im Hinblick auf eine mögliche Pandemie sind verbesserte Impftechnologien mit höherer Wirksamkeit oder kürzerer Produktionszeit dringend benötigt. Zudem gibt es Versuche, einen universellen Impfstoff zu produzieren, der nicht jedes Jahr appliziert werden muss.
Die klinische Autopsie – überholt?
Authors: Briner
Published: October 2007

Die Autopsie hat für den Kliniker die Funktion Diskrepanzen aufzudecken, Wissen zu vermitteln und Forschung zu stimulieren. Diskrepanz zwischen prä- und postmortem Befunden ist dabei nicht gleichbedeutend mit Fehler. Die ärztliche Tätigkeit entspricht trotz modernster technischer Hilfsmittel lediglich einer Wahrscheinlichkeitsrechnung (Clinical reasoning) basierend auf Wissen und Erfahrung. Die Qualität der Arbeit können wir nur verbessern, indem wir sie systematisch einer Kontrolle unterziehen. Die Autopsie stellt dabei eine Qualitätskontrolle dar, die zur Reduktion von relevanten Fehlern führt. Die Autopsie kann zudem den Angehörigen Informationen über die Ausdehnung eines Leidens oder mögliche vererbbare Krankheiten geben. Die Autopsie hat im 21. Jahrhundert nichts an ihrer Bedeutung verloren und muss weiterhin gefördert werden.
Currently active regions of decelerating‐accelerating seismic strain in central Asia
Authors: Papazachos B. C. , Scordilis E. M. , Panagiotopoulos D. G. , Papazachos C. B. , Karakaisis G. F.
Published: October 2007

Accelerating preshock seismic strain in a broad (critical) region and decelerating preshock seismic strain in a narrower (seismogenic) region constitute a model for intermediate‐term prediction of strong main shocks. An effort is made in the present work for a forward test of the Decelerating‐Accelerating Seismic Strain (D‐AS) model by identifying such patterns and estimating the corresponding, probably ensuing, strong main shocks (M ≥ 7.0) in central Asia (20°N–45°N, 42°E–105°E). Five such patterns have been identified, and the origin time, magnitude, and epicentral geographic coordinates of each of the corresponding main shocks have been estimated (predicted). Model uncertainties of the estimated time, magnitude, and space parameters of these probably ensuing main shocks, as well as appropriate statistical tests against a standard Gutenberg‐Richter seismicity distribution, are also presented to allow a future objective evaluation of the model's efficiency for intermediate‐term earthquake prediction.
Upscaling particle transport in discrete fracture networks: 1. Nonreactive tracers
Authors: Frampton A. , Cvetkovic V.
Published: October 2007

We study tracer transport through discrete fracture networks and develop a methodology for upscaling particle breakthrough curves on the basis of fracture segment data. Our prime interest is to model the early arrival and peak of tracer breakthrough curves, i.e., to capture the bulk of the tracer mass arrival. This study is based on two‐dimensional discrete fracture network simulations, combined with a truncated one‐sided stable distribution as a model for upscaling particle transitions. Results indicate that this model can accurately capture the bulk mass and peak of the breakthrough distributions for an upscaled distance of at least 1 order of magnitude in terms of transport scale, which for our simulations is about 2 orders of magnitude greater than the mean fracture segment scale. We also introduce an accurate mapping algorithm for transforming Eulerian into Lagrangian flow statistics, without a priori knowledge of network connectivity.
Upscaling particle transport in discrete fracture networks: 2. Reactive tracers
Authors: Frampton A. , Cvetkovic V.
Published: October 2007

We study sorbing tracer transport through discrete fracture networks using a stochastic Lagrangian framework, combined with the methodology for upscaling particle breakthrough curves developed in the first part of this article series. Results indicate that this procedure can accurately predict expected normalized tracer discharge for an upscaled distance of 1 order of magnitude in terms of transport scale, which for our simulations is about 2 orders of magnitude greater than the mean fracture segment scale. Specifically, we show the importance of retaining the correlation between the water residence timeτand the hydrodynamic control of retentionβin order to make accurate tracer discharge predictions. Also, we show that the extreme tails ofτandβdistributions have essentially no impact on tracer discharge. These results are illustrated using the unlimited diffusion model, and for two hypothetical tracers with properties designed to capture the behavior of many commonly occurring natural radionuclides.
A program for magnetic susceptibility–equivalent pore conversion
Authors: Jezek J. , Hrouda F.
Published: October 2007

Pore magnetic anisotropy can be used to estimate the average geometry of void spaces in rocks in the form of the equivalent pore (EP) ellipsoid. Direct computation of EP from measured magnetic susceptibility is impossible. We present a method and a Matlab program for automatic magnetic susceptibility–equivalent pore conversion. Input data are the magnetic parameters (P and T, or L and F) representing the bulk magnetic anisotropy, and the intrinsic susceptibility of the fluid used in the measurement. EP is estimated iteratively by a repeated look‐up table procedure using P and T values computed in a coarse grid of EP axial ratios. The program may be downloaded from the EarthRef.org Digital Archive.
Consumption of dissolved oxygen in the deep Japan Sea, giving a precise isotopic fractionation factor
Authors: Nakayama Noriko , Obata Hajime , Gamo Toshitaka
Published: October 2007

Concentrations and stable isotopic compositions (δ18O) of dissolved O2 in samples collected in May 2005 from the eastern Japan Sea were measured. The O2 consumption rate and the isotopic fractionation factor (αr) during dissolved O2 consumption were obtained from the field observations by applying a simple model to the deep water. The in‐situ O2 consumption rates were calculated from the apparent O2 utilization and the turnover time of deep water obtained in the previous tracer studies. The rates were 1.2–1.4 μmol kg−1 yr−1 in the deep water below 2000 m. The αr estimated was 0.9875 ± 0.0003 applying a Rayleigh distillation equation to the quasi‐deep water mass of 298–3584 m. The estimated αr and the turnover time mean that δ18O of dissolved O2 will increase with a rate of 0.05–0.06‰ yr−1 for the closed Japan Sea deep water mass.
Low‐altitude measurements of 2–6 MeV electron trapping lifetimes at 1.5 ≤ L ≤ 2.5
Authors: Baker D. N. , Kanekal S. G. , Horne R. B. , Meredith N. P. , Glauert S. A.
Published: October 2007

During the Halloween Storm period (October–November 2003), a new Van Allen belt electron population was powerfully accelerated. The inner belt of electrons formed in this process decayed over a period of days to years. We have examined quantitatively the decay rates for electrons seen in the region of 1.5 ≤ L ≤ 2.5 using SAMPEX satellite observations. At L = 1.5 the e‐folding lifetime for 2–6 MeV electrons was τ ∼ 180 days. On the other hand, for the half‐dozen distinct acceleration (or enhancement) events seen during late‐2003 through 2005 at L ∼ 2.0, the lifetimes ranged from τ ∼ 8 days to τ ∼ 35 days. We compare these loss rates to those expected from prior studies. We find that lifetimes at L = 2.0 are much shorter than the average 100–200 days that present theoretical estimates would suggest for the overall L = 2 electron population. Additional wave‐particle interaction aspects must be included in theoretical treatments and we describe such possibilities here.
Trends in midlatitude cyclone frequency and occurrence during fire season in the Northern Rockies: 1900–2004
Authors: Knapp Paul A. , Soulé Peter T.
Published: October 2007

We examined changes in the timing and frequency of major midlatitude cyclones (MLCs) during August through October for eight climate stations in the Northern Rockies from 1900–2004. As MLCs can effectively diminish fire activity through both cooler temperatures and higher humidity/precipitation, we also determined if area burned by wildfires from 1940–2004 was correlated with the timing and frequency of these events. Our results indicate that: (1) significant long‐term trends in MLCs exist, as the timing of the first MLC has occurred later in the year during the past century, with a marked upward shift post‐mid‐1980s; (2) MLC frequency has significantly declined since 1900, with a pronounced decrease also beginning in the mid‐1980s; (3) the relationships between the timing of the first MLC and frequency of MLCs with forest area burned are significant; and (4) mid‐tropospheric ridging upstream from the Northern Rockies that blocks MLCs has become more pronounced.
Effects of solar variability on thermosphere density from CHAMP accelerometer data
Authors: Guo Jianpeng , Wan Weixing , Forbes Jeffrey M. , Sutton Eric , Nerem R. Steven , Woods T. N. , Bruinsma Sean , Liu Libo
Published: October 2007

Thermosphere densities near 410 km altitude inferred from accelerometer measurements on the Challenging Minisatellite Payload (CHAMP) satellite are analyzed for solar irradiance variability effects during the period 2002–2004. Correlations between the densities and the solar irradiances for different spectral lines and wavelength ranges reveal significantly different characteristics. The density correlates remarkably well with all the selected solar irradiances except the lower chromospheric O I (130.4 nm) emission. Among the chosen solar proxies, the Mg II core‐to‐wing ratio index, EUV (30–120 nm) and F10.7 show the highest correlations with the density for short‐term (<∼27 d) variations. For both long‐term (>∼27 d) and short‐term variations, linear correlation coefficients exhibit a decreasing trend from low latitudes toward high latitudes. The density variability can be effectively modeled (capturing 71% of the variance) using multiple solar irradiance indices, including F10.7, SEUV (the EUV 30–120 nm index), and SFUV (the FUV 120–193 nm index), in which a lag time of 1 d was used for both F10.7 and SEUV, and 5 d for SFUV. In our regression formulation, SEUV has the largest contribution to the density variation (40%), with the F10.7 having the next largest contribution (32%) and SFUV accounting for the rest (28%). Furthermore, a pronounced period of about 27.2 d (mean period of the Sun's rotation) is present in both density and solar irradiance data of 2003 and 2004, and a pronounced period of about 54.4 d (doubled period of the solar rotation) is also revealed in 2004. However, soft X‐ray and FUV irradiances did not present a pronounced 54.4‐d period in 2004, in spite of their high correlation with the densities. The Ap index also shows 54‐d periodicities in 2004, and magnetic activity, together with solar irradiance, affects the 54‐d variation in density significantly. In addition, NRLMSISE00, DTM‐2000, and JB2006 model predictions are compared with density measurements from CHAMP to assess their accuracy, and the results show that these models underestimate the response of the thermosphere to variations induced by solar rotation.
Potassium lidar temperatures and densities in the mesopause region at Spitsbergen (78°N)
Authors: Höffner J. , Lübken F.‐J.
Published: October 2007

Lidar measurements of potassium temperatures and number densities were performed in the upper mesosphere/lower thermosphere at Spitsbergen (78°N) in 2001–2003. The cumulative data set covers the season from March until September and altitudes from 80 to 110 km (less in summer). The seasonal variation of K densities shows a maximum from early April until late September, similar to other latitudes but opposite to other metals. Temperatures are derived from the Doppler broadened D1 line of potassium with a typical resolution of 1 km and 1 h, respectively. Systematic temperature uncertainties are approximately ±3 K. Statistical errors depend on integration times and are typically ±0.5–3 K for 1 d and 1 h, respectively. The K‐lidar temperatures are generally consistent with simultaneous and colocated in situ measurements by falling spheres. Temperatures show variability on all detectable scales. The magnitude of the fluctuations varies little with season and is remarkably similar to analog observations at lower latitudes (54°N). The summer mesopause is located at ∼90 km and is as cold as ∼120 K. In winter the mesopause is significantly higher (∼100–105 km), warmer (∼180–190 K), and less pronounced. Lowest temperatures are detected at the mesopause around 4 July (day of year = 185) which is approximately 2 weeks after astronomical midsummer. Large differences of more than ±20 K occur between mean K temperatures and empirical climatologies. The lower thermosphere is significantly colder compared to general circulation models.
Recent widening of the tropical belt: Evidence from tropopause observations
Authors: Seidel Dian J. , Randel William J.
Published: October 2007

Radiosonde measurements and reanalysis data are used to examine long‐term changes in tropopause behavior in the subtropics. Tropopause heights in the subtropics exhibit a bimodal distribution, with maxima in occurrence frequency above 15 km (characteristic of the tropical tropopause) and below 13 km (typical of the extratropical tropopause). Both the radiosonde and reanalysis data show that the frequency of occurrence of high tropopause days in the subtropics of both hemispheres has systematically increased during the past few decades, so that tropical characteristics occur more frequently in recent years. This behavior is consistent with a widening of the tropical belt, and the data indicate an expansion of about 5–8° latitude during 1979–2005.
An 8‐century tropical Atlantic SST record from the Cariaco Basin: Baseline variability, twentieth‐century warming, and Atlantic hurricane frequency
Authors: Black David E. , Abahazi Matthew A. , Thunell Robert C. , Kaplan Alexey , Tappa Eric J. , Peterson Larry C.
Published: October 2007

We present the first direct comparison and calibration of a downcore foraminiferal Mg/Ca record to historical instrumental sea surface temperature (SST). Mg/Ca measured on the planktic foraminifer Globigerina bulloides from a Cariaco Basin sediment core strongly correlate with spring (March–May) instrumental SSTs between A.D. 1870 and 1990. A Mg/Ca SST equation is derived and a paleo‐SST record is presented spanning the last 8 centuries, an interval that includes the end of the Medieval Warm Period and the Little Ice Age. The long‐term record displays a surprising amount of variability. The temperature swings are not necessarily related to local upwelling variability but instead represent wider conditions in the Caribbean and western tropical Atlantic. The Mg/Ca SST record also captures the decadal and multidecadal variability observed in records of global land and sea surface temperature anomalies and Atlantic tropical storm and hurricane frequency over the late nineteenth and twentieth centuries. A divergence between the SST proxy record and Atlantic storm frequency around 1970 appears to reflect a fundamental change in Atlantic hurricane behavior noted in historical data. On average, twentieth‐century temperatures are not the warmest in the entire record, but they do show the largest increase in magnitude and fastest rate of SST change over the last 800 a.
Electromagnetic scattering by semi‐infinite circular and elliptic cones
Authors: Klinkenbusch L.
Published: October 2007

The scattering of a plane electromagnetic wave by a perfectly conducting semi‐infinite cone with an elliptic or a circular cross section is treated by means of a multipole analysis in sphero‐conal coordinates, in which the elliptic (including the circular) cone is one of the coordinate surfaces. Starting from the dyadic Green's function of the elliptic cone given in terms of periodic and nonperiodic Lamé functions, first the exact surface current on the cone is obtained. This surface current is the source of the scattered far field which is completely analytically found by means of the dyadic Green's function of the free space in sphero‐conal coordinates. The finally obtained infinite series do not converge by a straight‐forward summing‐up procedure; however, a simple linear (consistent) sequence transformation technique is sufficient to come to stable and physically correct asymptotic results.