bluuebunny/crossref_metadata_2025 huggingface dataset:
Profiling of trichorzianines in culture samples of Trichoderma atroviride by liquid chromatography/tandem mass spectrometry
Authors: Stoppacher Norbert , Reithner Barbara , Omann Markus , Zeilinger Susanne , Krska Rudolf , Schuhmacher Rainer
Published: November 2007

Peptaibols are bioactive linear peptides of 5–20 amino acid residues and contain specific non‐proteinogenic amino acids such as α‐aminoisobutyric acid (Aib). They are antibiotic secondary metabolites of moulds belonging predominantly to the genus Trichoderma, some species of which are successfully used as biocontrol organisms to fight against plant diseases. In the present study we developed a profiling method for the relative quantification of 16 trichorzianine peptaibols in culture samples of T. atroviride and the comparison of their expression patterns by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI‐MS/MS). The method is based on selected reaction monitoring (SRM) in a triple‐quadrupole tandem mass spectrometer using three SRM transitions per compound. The trichorzianines were enriched by solid‐phase extraction (SPE) on C18 cartridges. SPE recoveries were evaluated for diluted trichorzianine standard solutions and ranged from 72–97%. Suppression of the ionisation of the peptaibols in the ESI source ranged from 67–128% for most of the trichorzianines in culture filtrates of two different strains of T. atroviride and in spiked culture medium. In the case of trichorzianines TA Vb, TA VIa and TA VIb the presence of matrix components in the fungal culture samples caused a reduction of the SRM signal, with intensities between 34% and 56% relative to pure standard solutions. Finally, the profiling method was successfully applied to culture samples of T. atroviride P1 wild‐type and two deletion mutants showing different trichorzianine expression patterns characteristic for the investigated fungal strains. This is the first LC‐SRM profiling method for peptaibols for the investigation of peptaibol expression patterns in fungal culture samples. Copyright © 2007 John Wiley & Sons, Ltd.
Automated bone contour detection in ultrasound B‐mode images for minimally invasive registration in computer‐assisted surgery—an in vitro evaluation
Authors: Kowal Jens , Amstutz Christoph , Langlotz Frank , Talib Haydar , Ballester Miguel Gonzalez
Published: November 2007

Background

Minimally invasive surgical interventions performed using computer‐assisted surgery (CAS) systems require reliable registration methods for pre‐operatively acquired patient anatomy representations that are compatible with the minimally invasive paradigm. The use of brightness‐mode ultrasound seems to be promising, if associated devices work in a computationally efficient and fully automatic manner.

Methods

This paper presents a rapid and fully automatic segmentation approach for ultrasound B‐mode images capable of detecting echoes from bony structures. The algorithm focuses on the precise and rapid detection of bone contours usable for minimally invasive registration. The article introduces the image‐processing scheme and a set‐up enabling a direct comparison between manually digitized reference points and the segmented bone contours. The segmentation accuracy was assessed using cadaveric material.

Results

The experimental evaluation revealed results in the same order of magnitude as a pointer‐based surface digitization procedure.

Conclusion

The suggested segmentation approach provides a reliable means of detecting bony surface patches in ultrasound images. Copyright © 2007 John Wiley & Sons, Ltd.
Human cytomegalovirus DNA replication: antiviral targets and drugs
Authors: Mercorelli Beatrice , Sinigalia Elisa , Loregian Arianna , Palù Giorgio
Published: November 2007

Human cytomegalovirus (HCMV) infection is associated with severe morbidity and mortality in immunocompromised individuals, in particular transplant recipients and AIDS patients, and is the most frequent congenital viral infection in humans. There are currently five drugs approved for HCMV treatment: ganciclovir and its prodrug valganciclovir, foscarnet, cidofovir and fomivirsen. These drugs have provided a major advance in HCMV disease management, but they suffer from poor bioavailability, significant toxicity and limited effectiveness, mainly due to the development of drug resistance. Fortunately, there are several novel and potentially very effective new compounds which are under pre‐clinical and clinical evaluation and may address these limitations. This review focuses on HCMV proteins that are directly or indirectly involved in viral DNA replication and represent already established or potential novel antiviral targets, and describes both currently available drugs and new compounds against such protein targets. Copyright © 2007 John Wiley & Sons, Ltd.
What makes a process a capability? Heuristics, strategy, and effective capture of opportunities
Authors: Bingham Christopher B. , Eisenhardt Kathleen M. , Furr Nathan R.
Published: November 2007

While organizational processes, such as internationalization, acquisition, and alliance, are a fundamental concept within many literatures and central to firm capabilities, controversy exists regarding how they become high performing. One view emphasizes the role of experience while a second view emphasizes cognition and, in particular, the role of articulated heuristics. Using qualitative and quantitative field data on the internationalization process of entrepreneurial firms from three culturally distinct regions (Finland, U.S., Singapore), we juxtapose these two competing theoretical views to better gain insight into organizational processes and capabilities. The core contribution of our paper is insight into the structure of firm capabilities. Results show that organizational heuristics more closely relate to the development of a high performing process and hence a firm capability. At a broader level, we contribute to strategy by empirically validating the strategic logic of opportunity, a logic that is particularly relevant in dynamic markets and growth oriented firms. We also contribute to entrepreneurship by adding to the opportunity discovery vs. opportunity creation debate, and by shedding light on the relationship between structure and performance in new ventures. Overall, we contribute to the emerging but growing body of research emphasizing a more cognitive view of firms. Copyright © 2007 Strategic Management Society.
The accidental entrepreneur: the emergent and collective process of user entrepreneurship
Authors: Shah Sonali K. , Tripsas Mary
Published: November 2007

We develop a process model of how users, an understudied source of entrepreneurship, create, evaluate, share, and commercialize their ideas. We compare and contrast our model to the classic model of the entrepreneurial process, highlighting the emergent and collective nature of the user's entrepreneurial process. Users are often ‘accidental’ entrepreneurs who happen upon an idea through their own use and then share it with others; more specifically, the development of an idea and subsequent experimentation, adaptation, and preliminary adoption often occur before that idea is formally evaluated as the basis of a commercial venture. Users also tend to engage in collective creative activity prior to firm formation—often within the social context provided by user communities—that results in the improvement of ideas. Finally, we provide detailed data on the prevalence of user entrepreneurship in the juvenile products industry. Copyright © 2007 Strategic Management Society.
Discovery and creation: alternative theories of entrepreneurial action
Authors: Alvarez Sharon A. , Barney Jay B.
Published: November 2007

Do entrepreneurial opportunities exist, independent of the perceptions of entrepreneurs, just waiting to be discovered? Or, are these opportunities created by the actions of entrepreneurs? Two internally consistent theories of how entrepreneurial opportunities are formed – discovery theory and creation theory – are described. While it will always be possible to describe the formation of a particular opportunity as an example of a discovery or creation process, these two theories do have important implications for the effectiveness of a wide variety of entrepreneurial actions in different contexts. The implications of these theories for seven of these actions are described, along with a discussion of some of the broader theoretical implications of these two theories for the fields of entrepreneurship and strategic management. Copyright © 2007 Strategic Management Society.
Toward non‐parametric and clinically meaningful moderators and mediators
Authors: Kraemer Helena Chmura
Published: November 2007

There is growing realization of the importance in randomized clinical trails (RCTs) and in risk research of understanding, not merely that a treatment or a risk factor has an effect on the outcome but specifically on whom in the population sampled does a treatment or a risk factor have such effects (via moderators), how those effects might be achieved (via mediators), and how clinically significant such effects might be (via effect sizes). Classic methods of detection of moderators and mediators have been based on statistical significance in linear models, procedures that often produce inconsistent results hard to interpret in terms of clinical significance. Methods based on non‐parametric methods specifically designed to facilitate considerations of clinical significance are here introduced for binary moderators and mediators and the discussion opened for what would be needed in general. Copyright © 2007 John Wiley & Sons, Ltd.
Improvement of Intraoperative Frozen Section Diagnosis in Patients with Biliary Strictures by Levovist Injection into the Bile Duct on Color Doppler Ultrasonography
Authors: Aimoto Takayuki , Uchida Eiji , Kawahigashi Yutaka , Nakamura Yoshiharu , Matsushita Akira , Katsuno Akira , Chou Kazumitsu , Kawamoto Masao , Yamanaka Yoichiro , Tajiri Takashi , Naito Zenya
Published: November 2007

Background

This study evaluates the efficiency of color Doppler ultrasonography‐guided intraoperative pancreatic biopsy (CDUS‐IPB) using Levovist injected into the bile duct in conjunction with stimulated acoustic emission (SAE) in patients with biliary strictures.

Methods

The study was performed on 12 patients. After completing a conventional intraoperative pancreatic biopsy (c‐IPB), each subject underwent CDUS with SAE imaging using Levovist. Upon identification of the biliary stricture, the IPB was taken from the area surrounding the stricture on the same imaging setting. Section diagnosis of the CDUS‐IPB specimen was compared to that of the c‐IPB specimen and resected tissue.

Results

Biliary strictures were identified as enhanced areas of color Doppler signal on CDUS. CDUS‐IPB provided adequate specimens from the biliary strictures in all cases and corrected false‐negative diagnoses by c‐IPB in three cases. Section diagnosis by CDUS‐IPB corresponded to the permanent section diagnosis. There were no complications.

Conclusions

CDUS‐IPB with Levovist is an accurate diagnostic tool. The method is especially useful for patients with a suspected malignant biliary stricture who show no tumor mass in preoperative images and no evidence of malignancy on cytologic examinations.
Long‐Term Outcome of Liver Resection for Hepatocellular Carcinoma in Noncirrhotic Nonfibrotic Liver with No Viral Hepatitis or Alcohol Abuse
Authors: Lubrano Jean , Huet Emmanuel , Tsilividis Basile , François Arnaud , Goria Odile , Riachi Ghassan , Scotté Michel
Published: November 2007

Background

Hepatocellular carcinoma (HCC) occurs primarily in cirrhotic liver, with less than 10% occurring in normal liver parenchyma. Limited studies have described the outcome of liver resection in strictly normal liver parenchyma with no cirrhosis, fibrosis, underlying viral hepatitis, alcohol abuse, or dysmetabolic syndrome.

Materials and methods

Between January 1986 and 2005, a total of 321 patients were referred to our institution for HCC. Of these patients, 20 (6.2%) underwent surgery for HCC arising in noncirrhotic nonfibrotic liver parenchyma; they comprise our study group. Pathology examinations were reviewed based on the Chevallier fibrosis score and the Metavir viral score. Pre‐, per‐, and postoperative data were collected to assess their influence on tumor recurrence and survival.

Results

The median age was 57 years (35–80 years), and 71% patients were male. α‐Fetoprotein serum levels were normal in 9 patients. A preoperative diagnosis was made in 14 cases. Morbidity and morality rates were 10% and 5%, respectively. The 1‐, 3‐, and 5‐year survival rates were 85%, 70%, and 64%, respectively; and disease‐free survivals at 1, 3, and 5 years were 84%, 66%, and 58%, respectively. Eight patients had a recurrence with a median delay of 15 months (2–70 months). Univariate analysis showed that survival was influenced by preoperative cytolysis, R0 resection, recurrence, and recurrence within 1 year. A multivariate analysis revealed that recurrence and recurrence within 1 year significantly decreased survival. The 1‐, 3‐, and 5‐year survival rates of patients with recurrence were 75%, 37%, and 25%, respectively.

Conclusion

These results for HCC in patients with normal liver parenchyma justify liver resection and underline the differences in outcome of patients with HCC in a cirrhotic liver.
Deletion of a single mevalonate kinase (Mvk) allele yields a murine model of hyper‐IgD syndrome
Authors: Hager E. J. , Tse H. M. , Piganelli J. D. , Gupta M. , Baetscher M. , Tse T. E. , Pappu A. S. , Steiner R. D. , Hoffmann G. F. , Gibson K. M.
Published: November 2007

In the current study our objective was to develop a murine model of human hyper‐IgD syndrome (HIDS) and severe mevalonic aciduria (MA), autoinflammatory disorders associated with mevalonate kinase deficiency (MKD). Deletion of one Mvk allele (Mvk+/−) yielded viable mice with significantly reduced liver Mvk enzyme activity; multiple matings failed to produce Mvk−/− mice. Cholesterol levels in tissues and blood, and isoprene end‐products (ubiquinone, dolichol) in tissues were normal in Mvk+/− mice; conversely, mevalonate concentrations were increased in spleen, heart, and kidney yet normal in brain and liver. While the trend was for higher IgA levels in Mvk+/− sera, IgD levels were significantly increased (9–12‐fold) in comparison to Mvk+/+ littermates, in both young (<15 weeks) and older (>15 weeks) mice. Mvk+/− animals manifested increased serum TNF‐α as compared to wild‐type littermates, but due to wide variation in levels between individual Mvk+/− mice the difference in means was not statistically significant. Mvk+/− mice represent the first animal model of HIDS, and should prove useful for examining pathophysiology associated with this disorder.
Three-dimensional computed tomography analysis and anteversion study after periacetabular osteotomy of pelvis in children
Authors: Jawish Roger , Khalife Rami , Ghorayeb Jacques
Published: November 2007

Purpose

Three-dimensional computed tomography (CT) is the method of choice in understanding the morphological changes after periacetabular osteotomy in children. We studied different parameters and compared aspects of operated hip (OH) with non-operated hip (NOH) to define the maneuver that promotes normalization of the hip during repositioning of the acetabulum.

Methods

A total of 22 patients with 25 OHs underwent CT control scans an average of 4 years after surgery. The patients, with a mean age of 6.8 years, had either Legg-Calvé-Perthes disease (12 cases) or dysplasia (10 cases).The measurements included the anterior and posterior coverage angles of the hip and version of the acetabulum on axial CT views. The 3D reconstructed images measured the inclination of the antero– and postero–lateral lips, the external rotation and the anterior inclination of the acetabulum.

Results

The mean anterior coverage angle was 27° for OHs, 31° for NOHs, and 12° versus 10.3° for the posterior coverage angle. Acetabular anteversion was 2° for OHs (6.3° in the dysplastic OHs) and 6° for NOHs. The mean angle of inclination of the antero–lateral lip was 37° for OHs, 47° for NOHs, and the postero–lateral lip inclination was 56° for OHs and 67° for NOHs. Inferior 3D views showed a mean internal acetabular rotation of 1.5° (4.8° in the dysplastic OH), 3° for NOH. The anterior acetabular inclination angle measured with lateral 3D views was 6° for OHs, 11° for NOHs.

Conclusion

Our analysis demonstrated a mean anteversion of the acetabulum despite normalization of the anterior coverage of the hip, particularly in the dysplastic group, in which the osteotomized fragments had anteversion superior to NOH. The unexpected external rotation used to improve anterior coverage of a coax magna in Legg-Calvé-Perthes disease was responsible for the retroversion and the decrease of the posterior coverage.
Dietary patterns in pregnant women: a comparison of food-frequency questionnaires and 4 d prospective diaries
Authors: Crozier Sarah R. , Inskip Hazel M. , Godfrey Keith M. , Robinson Siân M.
Published: November 2007

There is growing interest in the use of dietary patterns as measures of exposure in studies of diet–disease relationships. However, relatively little is known about the impact of the type of dietary assessment method on the patterns observed. Using FFQ and food diary data collected from 585 women in early pregnancy we used principal component analysis to define dietary patterns. The first pattern was very similar in both datasets and was termed the ‘prudent’ diet. The second pattern, whilst comparable for the FFQ and food diaries, showed greater variation in coefficients than the prudent pattern; it was termed the ‘Western’ diet. Differences between the FFQ and diary scores were calculated for each woman for both the prudent and Western diet patterns. Of the differences in the prudent diet score, 95 % lay within ± 1·58 sd of the mean, and 95 % of the differences in the Western diet scores lay within ± 2·22 sd of the mean. Pearson's correlation coefficients were 0·67 (P < 0·001) for the prudent diet score and 0·35 (P < 0·001) for the Western diet score. The agreement between the FFQ and diary scores was lowest amongst respondents who were younger, had lower educational attainment and whose diaries were coded as ‘poor, probably incomplete’, although these effects were small. The first two dietary patterns identified in this cohort of pregnant women appear to be defined similarly by both FFQ and diary data, suggesting that FFQ data provide useful information on dietary patterns.
Fatty acid composition of serum lipid classes in mice following allergic sensitisation with or without dietary docosahexaenoic acid-enriched fish oil substitution
Authors: Rühl Ralph , Koch Christin , Marosvölgyi Tamás , Mihály Johanna , Schweigert Florian J. , Worm Margitta , Decsi Tamás
Published: November 2007

Dietary fatty acids have been shown to influence allergic sensitisation. Bothn-3 andn-6 PUFA are involved in targeted mediation of inflammatory responses during allergic sensitisation and manifestation of atopic diseases. In the present experiments we investigated whether supplementation of DHA-enriched fish oil partly substituting dietary sunflower-seed oil, in comparison with sunflower-seed oil, supplemented to mice influences fatty acid composition of serum lipid classes. The effects of the two different diets were also investigated depending on allergic sensitisation. Supplementation of DHA and EPA in doses of 2 and 0·12 % (w/w) to non-sensitised and sensitised mice resulted in significantly increased percentile contributions of DHA to all lipid classes. In contrast, serum values of then-6 PUFA arachidonic acid (AA) were significantly lower, both in non-sensitised and sensitised mice fed the DHA-enriched diet. The fatty acid composition of serum lipids also reflected allergic sensitisation: the EPA:AA ratio in TAG, cholesteryl esters and phospholipids in non-supplemented animals fell to 23, 29 and 29 % respectively of the original value after allergic sensitisation, whereas it decreased to 70, 80 and 76 % respectively only in the animals supplemented with DHA. In summary, allergic sensitisation alone decreased significantly the EPA:AA ratios in serum TAG, while concomitant supplementation of DHA-enriched fish oil ameliorated this decrease. We postulate from the present results that the amelioration of the severity of allergic sensitisation after DHA supplementation may be linked to altered ratios of the eicosanoid precursors EPA and AA as well as DHA needed for further metabolic activation to pro- or anti-inflammatory bioactive lipids.
The acute effects of psyllium on postprandial lipaemia and thermogenesis in overweight and obese men
Authors: Khossousi A. , Binns C. W. , Dhaliwal S. S. , Pal S.
Published: November 2007

Overweight and obesity is one of the risk factors for developing CVD. At present, very little is known about the acute effects of dietary fibre on lipids, glucose and insulin, resting energy expenditure and diet-induced thermogenesis in overweight and obese individuals. This study examined the postprandial metabolic effects of dietary fibre in overweight and obese men. Ten overweight and obese men consumed a mixed meal accompanied by either a high-fibre or low-fibre supplement on two separate visits, in a random order, 1 week apart. Two isoenergetic breakfast meals with similar composition were consumed by ten overweight/obese men. The meals contained either a low (3 g) or high (15 g) amount of fibre, low-fibre meal (LFM) and high-fibre meal (HFM) respectively. Analysis was carried out using paired t test and ANOVA. Serum TAG incremental area under the curve during 6 h of the postprandial period was significantly lower after the consumption of HFM compared with LFM. At the first hour of the postprandial period, plasma apo B48 concentration after consumption of HFM was significantly lower compared with LFM. The resting energy expenditure and diet-induced thermogenesis after both meals was similar during 6 h of the postprandial period. Collectively, these findings suggest that a single acute dose of dietary fibre in the form of psyllium supplement can decrease arterial exposure to TAG and modify chylomicron responses in the postprandial period.
Contribution of some grape-derived aromatic compounds to the primary aroma in red wines from cv. Caiño Tinto, cv. Caiño Bravo and cv. Caiño Longo grapes
Authors: VILANOVA M. , CORTÉS S. , SANTIAGO J. L. , MARTÍNEZ C. , FERNÁNDEZ E.
Published: November 2007

The free volatile compounds of two successive vintages of cv. Caiño Tinto, Caiño Bravo and Caiño Longo red wines, together with the volatile compounds released after the enzymatic hydrolysis of their glycosidically bound forms, were identified and quantified by gas chromatography using a flame ionization detector (GC/FID). All these wines possessed the same free volatile compounds; Caiño Longo wines showed the highest concentrations and Caiño Tinto wines the lowest. In all cases, the release of the bound forms of these compounds may contribute to the final aroma, from both a qualitative standpoint (with the appearance of free 4-terpineol, nerol and geraniol) and quantitative standpoint (notable increases were recorded for most of the compounds detected). The principal component analysis (PCA) showed a good separation of the different wine cultivars and vintages. Caiño Tinto wines were more homogeneous between vintages than the others.
QUALITY OF ANTENATAL CARE AND ITS DOSE–RESPONSE RELATIONSHIP WITH BIRTH WEIGHT IN A MATERNAL AND CHILD HEALTH TRAINING INSTITUTE IN BANGLADESH
Authors: KHATUN SELINA , RAHMAN MAHMUDUR
Published: November 2007

Four hundred and sixty-five pregnant women and their newborn babies were studied at a maternal and child health training institute in Dhaka, Bangladesh, between July 2002 and June 2003 with the objective of (1) examining the relationship between birth weight and maternal factors, and, if there was a dose–response relationship between quality of antenatal care and birth weight, (2) predicting the number of antenatal visits required for women with different significant characteristics to reduce the incidence of low-birth-weight babies. The study revealed that 23·2% of the babies were of low birth weight according to the WHO cut-off point of <2500 g. Mean birth weight was 2674·19±425·31 g. A low birth weight was more common in younger (<20 years) and older (≥30 years) mothers, the low-income group and those with little or no education. The mean birth weight of the babies increased with an increase in quality of antenatal care. The babies of the mothers who had 6+ antenatal visits were found to be 727·26 g heavier than those who had 1–3 visits and 325·88 g heavier than those who had 4–5 visits. No significant relationship was found between number of conception, birth-to-conception interval, BMI at first visit, sex of the newborn and birth weight. Further, from multiple regression analysis (stepwise), it was revealed that number of antenatal visits, educational level of the mother and per capita yearly income had independent effects on birth weight after controlling the effect of each variable. Using multiple regression analysis, the estimated number of antenatal visits required to reduce the incidence of low-birth-weight babies for women with no education and below-average per capita income status was 6; the number required for women with no education and above-average per capita income status was 5; and that for women with education and with any category of income status was 4 visits. So there is a need to stratify women according to their income and educational status so that, along with other measures, the required number of antenatal visits can be estimated beforehand to reduce the incidence of low-birth-weight babies.
Prevalence and intensity ofToxocara canis(Werner, 1782) in dogs and its potential public health significance in Ile-Ife, Nigeria
Authors: Sowemimo Oluyomi A.
Published: November 2007

A study on the prevalence and intensity ofToxocara canis(Werner, 1782) in dogs was carried out in Ile-Ife, Nigeria. Faecal samples were collected from 269 dogs between January and December 2004, processed by the Kato–Katz technique and then examined forT. caniseggs. The prevalence ofT. canisobtained was 33.8%. The intensity of infection, measured as mean egg count per gram of faeces ( ± SEM) was 393.8 ± 83.4. The prevalence and intensity ofT. canisin dogs aged 0–6 months were significantly higher (P < 0.05) than older age groups. The prevalence and intensity ofT. canisinfection were significantly higher in males than in female dogs (P < 0.05). SinceT. canisis known to cause visceral larva migrans (VLM) in young children, there is the possibility that the high prevalence ofT. canisinfection obtained in this study might constitute an important risk factor for transmission to humans. Therefore, there is the need to educate the residents of Ile-Ife on the danger of close association of their children with household pets.
Unilateral associated laryngeal paralysis due to varicella-zoster virus: virus antibody testing and videofluoroscopic findings
Authors: Chitose S-I , Umeno H , Hamakawa S , Nakashima T , Shoji H
Published: November 2007

The relationship between varicella-zoster virus and idiopathic associated laryngeal paralysis was examined in five patients, using complement fixation or enzyme immunoassay testing. In all cases, significant changes in serum levels of varicella-zoster virus antibody were observed. Videofluoroscopy was useful in assessing the severity of the dysphagia and in making an accurate diagnosis; both laryngeal elevation and weakness of pharyngeal wall contraction were also observed. In two cases in which antiviral therapy was delayed, the outcome was poor, with increased levels of varicella-zoster virus immunoglobulin M found on enzyme immunoassay. The outcome of the condition may thus depend both on the speed of antiviral therapy commencement following onset of symptoms, and on the levels of varicella-zoster virus immunoglobulin M antibody (measured by enzyme immunoassay). Our study suggests that varicella-zoster virus should be considered in the differential diagnosis of patients with idiopathic associated laryngeal paralysis, and rapid antiviral therapy should be initiated when necessary.
On the theory of magneto-sound double simple waves
Authors: TSKHAKAYA DAVY D. , ESHRAGHI HOMAYOON
Published: November 2007

A two-dimensional double simple wave solution is given for both weakly and highly magnetized non-relativistic plasmas moving across the magnetic field. The dependence of the density and the magnetic field on the two independent phases, namely, components of the fluid velocity, is derived. It is shown that initial spatial distributions must satisfy a definite equation whose solution determines a special category for initial conditions. The time of blow up for any fixed value of the pair phase is found. A large general class of solutions for initial distributions is obtained. For any chosen initial distribution, the physical plane of flow at any instant of time splits into two regions, one forbidden and the other permitted. These regions are obtained numerically at a typical time for a special initial distribution. For this double wave solution, differential equations for streamlines and fluid trajectories are derived. Only for the simplest cases can the corresponding curves be completely integrated and these are given in this paper. The results are qualitatively similar to the one-dimensional case derived by Stenflo and Shukla.
A comparison between electron orbits for both an axial magnetic field and an ion-channel guiding in a FEL with an electromagnetic wave wiggler
Authors: MEHDIAN H. , JAFARI S.
Published: November 2007

The operation of a free-electron laser (FEL) with electromagnetic wave wiggler in the presence of an ion-channel guiding as well as an axial guide magnetic field is considered and compared. Theoretical studies of electron trajectories and dispersion relations in a combined ion electrostatic field as well as large-amplitude backward-propagating electromagnetic waves are analyzed. The large-amplitude wave acts like a magnetostatic wiggler in a FEL. The results of a numerical study are presented and discussed. It is shown that in the wiggler pumped ion-channel free-electron laser (WPIC-FEL), electron orbits and dispersion relation are time-dependent, and over time, electron orbits while oscillating bear a periodic motion.
Tuberculosis (Mycobacterium microti) in wild field vole populations
Authors: BURTHE S. , BENNETT M. , KIPAR A. , LAMBIN X. , SMITH A. , TELFER S. , BEGON M.
Published: November 2007

Vole tuberculosis (TB;Mycobacterium microti) is an understudied endemic infection. Despite progressing slowly, it causes severe clinical pathology and overt symptoms in its rodent host. TB was monitored for 2 years in wild field voles in Kielder Forest, UK. The prevalence of characteristic cutaneous TB lesions was monitored longitudinally at 4 sites, with individuals live-trapped and repeatedly monitored. A prevalence of 5·2% of individuals with lesions was recorded (n=2791). In a cross-sectional study, 27 sites were monitored bi-annually, with TB assessed by post-mortem examination for macroscopic lesions, and by culture and histopathology. Seventy-nine voles (10·78%;n=733) were positive for mycobacteria, with the highest prevalence in spring (13·15%;n=327). TB prevalence varied, with between 0% and 50% of voles infected per site. Prevalence increased with age (mass), and apparent seasonality was due to a higher proportion of older animals in spring. Survival analysis supported this result, with cutaneous lesions only manifesting in the advanced stages of infection, and therefore only being found on older voles. The body condition of individuals with lesions declined at the time when the lesion was first recorded, when compared to individuals without lesions, suggesting there may be an acute phase of infection during its advanced stage. Although predicted survival following the appearance of a cutaneous lesion was lower than for uninfected individuals, this was not significant.
Natural variability and distribution of trace elements in marine organisms from Antarctic coastal environments
Authors: Grotti Marco , Soggia Francesco , Lagomarsino Cristina , Riva Simona Dalla , Goessler Walter , Francesconi Kevin A.
Published: November 2007

In an attempt to improve the understanding of the natural variability and distribution of trace elements in Antarctic organisms, the concentrations of arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, vanadium and zinc in representative benthic species from two pristine coastal environments were measured and compared with literature data for other uncontaminated coastal ecosystems. Correlations between the elements, differences between the species and between the sampling sites were examined by principal component analysis. Metal accumulation was particularly evident in the tissues of the sea star Odontaster validus, the bivalve mollusc Laternula elliptica and in the red alga Phyllophora antarctica. However, metal accumulation was not the same for all the analytes, but, rather, depended on the organism characteristics. In particular, the soft tissues of Odontaster validus were characterized by high concentrations of cadmium, zinc and copper, those of Phyllophora antarctica by high concentrations of manganese and nickel, and the tissues of Laternula elliptica by high concentrations of all measured elements, particularly in its digestive gland. The Antarctic data as well as those reported for other pristine coastal ecosystems showed remarkably high natural variability in metal content, which must be taken into account when interpreting results from biomonitoring programmes.
Outcome Prediction of Cognitive Behaviour Therapy for Panic Disorder: Initial Symptom Severity is Predictive for Treatment Outcome, Comorbid Anxiety or Depressive Disorder, Cluster C Personality Disorders and Initial Motivation Are Not
Authors: Kampman Mirjam , Keijsers Ger P. J. , Hoogduin Cees A. L. , Hendriks Gert-Jan
Published: November 2007

Five variables were investigated with regard to their possible predictive value for cognitive behavioural treatment (CBT) outcome in a large sample of panic disorder (PD) patients. The variables were initial symptom severity, comorbid anxiety or depressive disorders, comorbid cluster C personality disorders, and initial motivation for treatment. A total number of 161 PD patients received a standardized CBT of 15 sessions. Assessments of predictive variables took place prior to treatment. Outcome measures were assessed at pre- and posttreatment. The patients had significantly improved after the treatment. None of the variables, separately or together, affected CBT outcome, save initial severity of panic disorder symptoms, which was positively associated with posttreatment symptom severity. Since research efforts failed to produce consistent predictors for CBT treatment outcome in panic disorder thus far, the usefulness of future outcome prediction research in panic disorder by pre-treatment demographic, disorder-related, psychological, or socio-psychological variables is put into question.
A NOTE ON THE JOINT OCCURRENCE OF INSURANCE AND GAMBLING
Authors: JONES LARRY E.
Published: November 2007

This note provides a formal justification for the Friedman and Savage nonconcavity in the utility of money. This is based on the possibility of indivisibilities in the consumption possibilities set. A precise characterization of when gambling is optimal (and the optimal type) is provided in one special case. Some possible limitations are considered.
Beyond-brand effect of television food advertisements on food choice in children: the effects of weight status
Authors: Halford Jason CG , Boyland Emma J , Hughes Georgina M , Stacey Leanne , McKean Sarah , Dovey Terence M
Published: November 2007

Objective

To investigate the effect of television food advertising on children’s food intake, specifically whether childhood obesity is related to a greater susceptibility to food promotion.

Design

The study was a within-subject, counterbalanced design. The children were tested on two occasions separated by two weeks. One condition involved the children viewing food advertisements followed by a cartoon, in the other condition the children viewed non-food adverts followed by the same cartoon. Following the cartoon, their food intake and choice was assessed in a standard paradigm.

Setting

The study was conducted in Liverpool, UK.

Subjects

Fifty-nine children (32 male, 27 female) aged 9–11 years were recruited from a UK school to participate in the study. Thirty-three children were normal-weight (NW), 15 overweight (OW) and 11 obese (OB).

Results

Exposure to food adverts produced substantial and significant increases in energy intake in all children (P < 0·001). The increase in intake was largest in the obese children (P = 0·04). All children increased their consumption of high-fat and/or sweet energy-dense snacks in response to the adverts (P < 0·001). In the food advert condition, total intake and the intake of these specific snack items correlated with the children’s modified age- and gender-specific body mass index score.

Conclusions

These data suggest that obese and overweight children are indeed more responsive to food promotion, which specifically stimulates the intake of energy-dense snacks.
What do babies eat? Evaluation of a food frequency questionnaire to assess the diets of infants aged 6 months
Authors: Marriott LD , Robinson SM , Poole J , Borland SE , Godfrey KM , Law CM , Inskip HM ,   The Southampton Women’s Survey Study Group
Published: November 2007

Objective

To evaluate the relative validity of a food frequency questionnaire (FFQ) for assessing nutrient intakes in 6-month-old infants.

Design and setting

The FFQ was developed to assess the diets of infants born to women in the Southampton Women’s Survey (SWS), a population-based survey of young women and their offspring. The energy and nutrient intakes obtained from an interviewer-administered FFQ were compared with those obtained from a 4-day weighed diary.

Subjects and methods

A sub-sample of 50 infants aged 6 months from the SWS had their diets assessed by both methods. The FFQ recorded the frequencies and amounts of milks, baby foods, regular foods and drinks consumed by the infants over the previous seven days. The diaries recorded the weights of all foods and drinks consumed by the infants on four separate days within 15 days following FFQ completion.

Results

Spearman rank correlation coefficients for intakes of energy, macronutrients and 18 micronutrients, determined by the two methods, ranged from r = 0·39 to 0·86; adjustment for energy intake tended to increase the correlation coefficients, range ra = 0·55 to 0·89. Bland–Altman statistics showed that mean differences between methods were in the range of −12·5 % to +12·5 % except for vitamin B12 (−18·9 %).

Conclusion

Although there were differences in absolute energy and nutrient intakes between methods, Spearman rank correlation coefficients indicated reasonable agreement in the ranking of intakes. The interviewer-administered FFQ is a useful tool for assessing energy and nutrient intakes of healthy infants aged about 6 months.
Education, demographics, and the economy
Authors: JAAG CHRISTIAN
Published: November 2007

This paper deals with two issues concerning the effects of population aging on education decisions in the presence of a PAYG pension system: We first analyze the effects of an aging population per se on individual skill choices and continuous education and the production structure. Second, we study the implications of postponed retirement, which is often proposed as a measure to cope with the economic challenges of increased longevity. Our study uses a dynamic general equilibrium framework with overlapping generations and probabilistic aging. The model allows for capital–skill complementarity in the production of final output.

As a response to population aging, in a small open economy with a fixed interest rate, our first simulation shows that GDP is depressed due to an adverse effect on skill choice and labor supply. We then introduce postponed retirement as a potentially dampening policy measure due to its encouragement of human capital formation. However, since there is less private saving in this scenario, the overall effect on GDP is even worse than in the pure aging scenario.
Operating costs of pension funds: the impact of scale, governance, and plan design
Authors: BIKKER JACOB A. , DE DREU JAN
Published: November 2007

Administrative and investment costs per participant appear to vary widely across pension funds. These costs are important because they reduce the rate of return on the investments of pension funds and consequently raise the cost of retirement security. This article examines the impact of determinants of these costs, such as the size, governance, pension plan design and outsourcing decisions, using data on all Dutch pension funds across the 1992–2004 period, including more than 10,000 observations. We find that economies of scale dominate the strong dispersion in both administrative and investment costs across pension funds. Industry-wide pension funds are significantly more efficient than company funds and other funds. The operating costs of pension funds' defined contribution plans are lower than those of defined benefit plans. Higher shares of pensioners make funds more costly, whereas the reverse is true when relatively many participants are inactive.
The G fund: portfolio effects of a dominant asset
Authors: REDDING LEE S.
Published: November 2007

The Thrift Savings Plan (TSP) is the defined contribution pension plan for the employees of the US Federal Government. It is also mentioned as a model to implement private investment accounts as part of US Social Security reform. The TSP has one unique investment opportunity – the Government Securities Investment Fund. This ‘G Fund’ is a short-term asset which pays long-term rates. This provides an implicit subsidy to federal employees. To collect this subsidy, however, employees must alter their portfolios. The subsidy may therefore be an inefficient means of compensating federal employees. Within a social security system, however, the G Fund would present the opportunity to partially ‘opt out’ of a private investment account.
Measurements of storm and nonstorm circulation in the northern Adriatic: October 2002 Through April 2003
Authors: Book J. W. , Signell Richard P. , Perkins Henry
Published: November 2007

Fifteen bottom‐mounted Acoustic Doppler Current Profilers were deployed from October 2002 through April 2003 in the northern Adriatic Sea. Average transport from the portion of the Western Adriatic Current (WAC) along the Italian slope was 0.1470 ± 0.0043 Sv, punctuated by bursts of more than twice that amount during storm events. Monthly means were calculated with times of strong wind‐driven circulation excluded. These suggest a 2002/2003 seasonal separation consisting of October, December through February, and March through April. An extreme Po River flood influenced November conditions making seasonal categorization difficult. October generally had more kinetic energy and more vertical structure than other months, and near‐inertial waves were more frequent in April and October. The Eastern Adriatic Current (EAC)/WAC (i.e. inflow/outflow) system was clearly present in the means for all months. The cyclonic gyre north of the Po River was present October through February. Generally, in the WAC, over 50% of kinetic energy came from vertically uniform monthly mean flows. Elsewhere, eddy kinetic energy was stronger than mean kinetic energy with 10–40% contributions for vertically uniform monthly mean flows, 40–60% for vertically uniform monthly varying flows, and 10–30% for vertically varying monthly varying flows. Mean currents for bora storms indicate enhancement of the EAC/WAC and the cyclonic northern gyre, a shift toward Kvarner Bay in EAC direction, a circulation null point south of the Po, and double‐gyre bifurcation of flow at Istria. Strengthening of both the EAC and WAC also occurs during sirocco storms.
Methods for thermochemical convection in Earth's mantle with force‐balanced plates
Authors: Brandenburg J. P. , van Keken P. E.
Published: November 2007

Models of convection in the mantle can be used to study the effects of differentiation and remixing on the geochemical evolution of the Earth. Implementation of melting and degassing at mid‐ocean ridges and subduction zones requires an adequate approximation of plate tectonics as well as temperature‐dependent rheology. We have developed a new two‐dimensional cylindrical model that combines a force‐balance method for energetically consistent stiff plates with tracer‐discretized chemical buoyancy. Basaltic crust is extracted at distinct spreading centers and is subducted into the lower mantle. We find that the unmodified implementation of the force‐balance equations in a full cylinder causes occasional spurious rotations by amplification of numerical discretization errors. The method is stable if a single internal symmetry boundary condition is used, but this causes artificial pooling of dense crust near the boundary where it is easily disrupted. This results in artificially enhanced remixing of dense crust. We modify the force‐balance equations to damp net lateral plate movement. The energetic consistency of this modification is then demonstrated by comparison to a one‐plate, single convection cell calculation. With the removal of the symmetry boundary condition a more continuous rate of crustal pooling is observed. This suggests that models with symmetry boundary conditions may overpredict the rate of pooling and remixing of ancient crust.
Energy‐Constrained Recharge, Assimilation, and Fractional Crystallization (EC‐RAχFC): A Visual Basic computer code for calculating trace element and isotope variations of open‐system magmatic systems
Authors: Bohrson Wendy A. , Spera Frank J.
Published: November 2007

Volcanic and plutonic rocks provide abundant evidence for complex processes that occur in magma storage and transport systems. The fingerprint of these processes, which include fractional crystallization, assimilation, and magma recharge, is captured in petrologic and geochemical characteristics of suites of cogenetic rocks. Quantitatively evaluating the relative contributions of each process requires integration of mass, species, and energy constraints, applied in a self‐consistent way. The energy‐constrained model Energy‐Constrained Recharge, Assimilation, and Fractional Crystallization (EC‐RaχFC) tracks the trace element and isotopic evolution of a magmatic system (melt + solids) undergoing simultaneous fractional crystallization, recharge, and assimilation. Mass, thermal, and compositional (trace element and isotope) output is provided for melt in the magma body, cumulates, enclaves, and anatectic (i.e., country rock) melt. Theory of the EC computational method has been presented by Spera and Bohrson (2001, 2002, 2004), and applications to natural systems have been elucidated by Bohrson and Spera (2001, 2003) and Fowler et al. (2004). The purpose of this contribution is to make the final version of the EC‐RAχFC computer code available and to provide instructions for code implementation, description of input and output parameters, and estimates of typical values for some input parameters. A brief discussion highlights measures by which the user may evaluate the quality of the output and also provides some guidelines for implementing nonlinear productivity functions. The EC‐RAχFC computer code is written in Visual Basic, the programming language of Excel. The code therefore launches in Excel and is compatible with both PC and MAC platforms. The code is available on the authors' Web sites http://magma.geol.ucsb.edu/and http://www.geology.cwu.edu/ecrafc) as well as in the auxiliary material.