bluuebunny/crossref_metadata_2025 huggingface dataset:
Aminimides XIII long chain aminimides and isocyanates
Authors: Freis R. E. , Grimm R. A. , McKillip W. J.
Published: April 2007

Aminimides were prepared from esters of stearic, oleic, linoleic, phenylstearic, 9,10‐dihydroxystearic, ricinoleic and dimer acids. Thermolysis of the aminimides to isocyanates was carried out in a wiped film molecular still and by vacuum distillation of a bulk sample. The latter process is suitable only for small samples of the simple aminimides. Acyl N,N‐dimethylhydrazides, which are aminimide precursors, can generally be prepared by dehydration of carboxylic acid‐unsym‐dimethylhydrazine mixtures. Details of the preparation of dimer acid diisocyanate by this route are presented. Some information on the use of long chain aminimides as emulsifiers for halocarbon mixtures, e.g., bromoform‐water, is presented.
Kinetic study of acid‐catalyzed conversion of aflatoxins B1 and G1 to B2a and G2a
Authors: Pons W. A. , Cucullu A. F. , Lee L. S. , Janssen H. J. , Goldblatt L. A.
Published: April 2007

Adjusting dilute aqueous solutions of aflatoxins B1 and G1 to pH 1, 2 and 3, and heating over a range of 40–100 C resulted in the conversion of B1 to B2a and G1 to G2a as major products. Both B2a and G2a were identified by co‐thin layer chromatography with authentic B2a and G2a and M1 on silica gel plates developed in two different solvents. The rate of disappearance of B1 or G1 at given temperature and at constant pH was found to be first order with respect to each aflatoxin. At given temperature the conversion is strongly pH dependent, a 10‐fold increase in H+ ion (1 pH unit) producing about a 9‐fold increase in the reaction rate, indicating first order dependent of the rate on H+ ion concentration.
New polyacetal, poly(ester‐acetal) and their urethane‐modified coatings from hydroformylated linseed oil
Authors: Khoe T. H. , Gast L. E. , Frankel E. N. , Cowan J. C.
Published: April 2007

Partly hydroformylated linseed oil, with an average of 1.3 to 3.4 meq aldehyde per gram of oil, was reacted with pentaerythritol hydroxymethyl linseed oil and trimethylolpropane in the presence of an acid catalyst to form viscous, high molecular weight polyacetals. Isophthalic acid or chlorendic anhydride‐modified polyacetals [poly(ester‐acetals)] were prepared by reacting the trimethylolpropane esters of the acids with the hydroformylated oils. Films of the products were cured at room temperature and at 140 C. These films showed good hardness as well as chemical and impact resistance. Further modification of these polyacetals and poly(ester‐acetals) by reacting the residual hydroxyl groups with an excess of toluene diisocyanate gave the corresponding isocyanate‐terminated prepolymers. Films from these prepolymers had shorter drying times and showed greater hardness than the corresponding unmodified materials.
Synthesis of methyl sterculate
Authors: Altenburger Erich R. , Berry James W. , Deutschman Archie J.
Published: April 2007

Methyl sterculate was isolated from an irradiation mixture obtained by photolysis of diazomethane in presence of methyl stearolate by column chromatography on silicic acid. The separable amount of the photoproduct was 9.5%. The presence of the cyclopropene structure was proved by spectroscopy and chemical methods.
Synthesis and properties of sulfated alkanolamides
Authors: Weil J. K. , Parris N. , Stirton A. J.
Published: April 2007

High purity alkanolamides were prepared by the sodium catalyzed reaction of methyl stearate, methyl palmitate and methyl laurate with ethanolamine, 2‐hydroxypropylamine, 3‐hydroxypropylamine and N‐methyl N‐hydroxyethylamine. The effect of structure on the surface active properties of the sulfation products was investigated. Stability studies showed that sulfated N‐methyl N‐hydroxyethylstearamide hydrolyzed rapidly by first order kinetics in acid or base. Sulfated hydroxyalkyl primary amides hydrolyzed slower in basic media following second order kinetics. Methyl groups attached to the N atom or to C in the short aliphatic chain improved solubility but had little effect on critical micelle concentration. The alkanolamides of palmitic and stearic acids were good detergents and lime soap dispersing agents.
Phase behavior of homologous series of monoesters of polyols
Authors: Lutton E. S. , Stewart C. B. , Fehl A. J.
Published: April 2007

Phase behavior of anhydrous monopalmitates and stearates and of most laurates, myristates and behenates of ethylene glycol, erythritol, xylitol, sorbitol, and mannitol has been studied. The compounds, substantially free of diesters, are mostly not isomerically pure but are predominantly primary esters. Also studied were the (nonisomeric) palmitate and stearate of pentaerythritol (Pe) and the oleate of erythritol. Mesomorphism, absent in anhydrous monoglycerides unless of short chain length and symmetrical, is a prominent feature of the members of the present group of compounds containing at least three unesterified hydroxyls. In general, crystal melting points rise with length of polyol, and mesomorphic melting points rise faster. Crystal melting points rise with acyl chain length while mesomorphic melting points run through a maximum. Heats of fusion are of the order 40 cal/g for crystal melting and 0.5 cal/g for melting of mesomorphic states. In the range explored, mesomorphic values fall with both polyol length and acyl length. At higher acyl chain length, notably with behenates, there are new features of mesomorphic behavior. Crystalline phase, from solvent, melts to a neat or lamellar phase, which in turn melts to liquid with subsequent appearance of higher melting middle or cylindrical phase. Polymorphism is general among the crystal states and tends to be complex. In a brief study of solvent crystallized 50–50 binary mixes of xylitol stearate with other xylitol esters and other stearates, considerable evidence of solid solution in Form I crystals (of xylitol stearate type) was observed with very modest eutectic lowering of crystal melting point. Mesomorphic points were almost linearly intermediate between those of components. Of particular interest were mixtures of xylitol stearate and 1‐monostearin (50–50 and 25–75), for which mesomorphic melting points were realized, and for which an extrapolation to 100% monostearin leads to a hypothetical mesomorphic melting point far below any monoglyceride crystalline melting point. A brief examination of an aqueous xylitol palmitate system explored to a maximum temperature of 165 C shows extensive occurrence of aqueous mesomorphic state somewhat after the manner of monoglyceride systems. Mesomorphic melting level rises rapidly from the value for anhydrous ester.
Computer‐guided explorations in lipid chemistry
Authors: Dutton Herbert J.
Published: April 2007

The concept of computer guided experimentation is illustrated in lipid research with recent examples of (1) simulations of chemical and physical phenomena, (2) processing of laboratory data, and (3) data acquisition in on‐line or real time mode.
Dimeric components from the dimerization of abietic acid
Authors: Fujii R. , Arimoto K. , Zinkel D. F.
Published: April 2007

Capillary gas‐liquid chromatography of the product formed by sulfuric acid‐catalyzed dimerization of abietic acid showed the presence of some 40 dimeric components. The three major components were isolated and shown to be heptacyclic dimers, two of which had a conjugated double bond system. The other component had two nonconjugated double bonds. Also isolated were three dimers consisting of monomers attached through a single carbon‐carbon bond: one carboxyl group in each of these dimers was in the form of a γ‐lactone.
Dietary protein and atherosclerosis
Authors: Kritchevsky David , Tepper Shirley A. , Klurfeld David M.
Published: April 2007

Interest in the effect of protein on lipid metabolism and atherosclerosis dates back to the first decade of this century. In the 1940s Meeker and Kesten showed that soy protein was more atherogenic for rabbits than casein. Carroll and his colleagues demonstrated that, in general, proteins of animal origin were more cholesterolemic for rabbits than were plant proteins, although there was a wide range of individual effects within both classifications. Carroll also showed that partial hydrolyzates of casein or soy protein were less cholesterolemic than the intact proteins. We have hypothesized that the lysine/arginine ratio (L/A) of the protein influences its effects on lipid metabolism. The L/A of casein is about 2 and that of soy about 1. Addition of enough arginine to casein to lower its L/A to 1 reduces its atherogenicity; adding enough lysine to soy isolate to raise its L/A to 2 enhances atherogenicity. The atherogenicities of fish protein (L/A, 1.44), casein (L/A, 1.94) and whole milk protein (L/A, 2.44) are correlated directly with their L/A (p<0.05). Other amino acids (methionine, glycine, arginine) have been shown to affect cholesterolemia. Casein lowers the excretion of steroids in rabbits and lengthens the turnover time of cholesterol. This may be the mechanism underlying the animal/vegetable protein effects.
Species‐dependent responsiveness of serum cholesterol to dietary proteins
Authors: Van Der Meer R. , Beynen A. C.
Published: April 2007

Substitution of casein for soybean protein in the diet causes high degrees of hypercholesterolemia in rabbits. When rats or humans were fed exactly the same diets, no response of the concentration of serum cholesterol to the type of protein was observed. The hypothesis is put forward that, in rabbits, dietary casein and peptides derived from it—because of their high degree of phosphorylation—inhibit the binding of glycine‐conjugated bile acids to insoluble calcium phosphate in the intestinal lumen. As a result, feeding of casein causes an increase in the availability of bile acids, which leads to enhanced absorption of bile acids and cholesterol. Eventually, the concentration of serum cholesterol will be increased. In rabbits this cascade of events occurs because these animals have a relatively low activity of intestinal alkaline phosphatase, and a high ratio of glycine to taurine in conjugated bile acids. Unlike glycine conjugates, taurine‐conjugated bile acids do not effectively bind to the intestinal calcium‐phosphate sediment. The low activity of intestinal alkaline phosphatase in rabbits secures the high degree of phosphorylation of casein and its peptide products in the small intestine. In contrast with rabbits, rats and humans have high activities of intestinal alkaline phosphatase and a low glycine‐to‐taurine ratio in conjugated bile acids. Thus the hypothesis presented would explain why rabbits, but not rats and humans, are susceptible to dietary casein with respect to the concentration of serum cholesterol. The relevance of the hypothesis as to the mechanisms underlying the hypercholesterolemic effect of some other dietary proteins is discussed.
Dietary protein effects on gallstone formation
Authors: Klurfeld David M. , Weber Maxine M. , Kritchevsky David
Published: April 2007

Semipurified lithogenic diets for hamsters contain casein as the protein source. Since substitution of soy protein isolate for casein reduces serum cholesterol concentrations in several species, we studied replacement of casein by soy protein for effects on gallstone formation. Feeding soy protein consistently resulted in a significantly reduced incidence of gallstones. Switching to a soy‐based diet after induction of gallstones resulted in dissolution of a significant percentage of the stones. Partial substitution of soy for casein gave results intermediate between 100% casein and 100% soy. The lysine/arginine ratio of the proteins may be responsible for the observed differences in cholelithiasis. The reduction in lithogenicity associated with feeding soy protein appears to be mediated primarily through decreased secretion of cholesterol into bile.
Shape, size, hydration and flow behavior of nitrocellulose lacquer emulsion in absence and presence of urea
Authors: Mandal Asit Baran
Published: April 2007

Viscometric and optical microscopic experiments, performed on nitrocellulose lacquer emulsions in the absence (Emulsion I) and presence (Emulsion II) of urea, indicate that in aqueous concentrated solutions at 30 C the emulsion droplets are spherical and non‐spherical in shape, respectively. Assuming spherical shape for both emulsions, the size and volume of the aggregated particle (Mv), radius of gyration (Rg), hydrodynamic radius (Rh), diffusion coefficient (D), the correlation time for aggregate rotation (Tr), translational diffusion (TD) and effective aggregation time (Ta) have been derived. The viscosity data for both emulsions were analyzed in terms of the Einstein, Moulik and Jones‐Dole equations. Emulsion II was more hydrated than Emulsion I, although the intrinsic viscosity (η) of Emulsion II is nearly 1.5 times greater than that of Emulsion I. The Huggins and Thomas equations have been compared for both emulsions, and it has been concluded, in light of the proposed Huggins‐Thomas‐Mandal equation, that the Thomas constant k1 should be 12.50 for perfect spherical shape of the particles in dilute solutions, instead of the 10.05 originally proposed by Thomas.
Spectrophotometric studies of the composition of lespedeza seed oil
Authors: Wiley Richard H. , Cagle A. W. , Wilken Phil H.
Published: April 2007

The ultraviolet absorption spectra of the oils obtained from lespedeza seeds of three species show an absorption similar to that of linseed oil. The spectra for the alkali isomerized lespedeza seed oils show triene conjugation equivalent to that which would be produced by the presence of 22–28% of a triunsaturated nonconjugated acid (such as linolenic acid) and 26–42% of a diunsaturated nonconjugated acid (such as linoleic acid). The presence of conjugated triene structure in the oil as extracted from a seed‐hull mixture ground with stainless steel balls was indicated by an absorption maximum at 270 mµ. Elimination of other possibilities suggest that this absorption is caused by a metal‐catalyzed isomerization or other reaction taking place only in the mixture.
Heat polymerization of safflower oil
Authors: Rhoades W. F. , Da Valle A. J.
Published: April 2007

It can be stated that the polymerization rate of safflower oil is sufficiently rapid to warrant its use on a commercial scale. Furthermore, with the proper choice of polymerization temperature, safflower can be bodied at the same rate as linseed. The increasing rate at which safflower bodies in the high viscosity ranges invites further investigation. In these higher viscosity ranges the iodine value continues to drop whereas in the same range the iodine numbers of other oils show a tendency to approach an asymptotic value.

Safflower heat bleaches considerably better than linseed and is also equal to or better than soya in this respect.
Phase relations pertaining to the solvent winterization of cottonseed oil in hexane and in acetone‐hexane mixtures
Authors: Boucher Richard E. , Skau Evald L.
Published: April 2007

Systematic phase relation data pertaining to the solvent winterization behavior of a refined cottonseed oil have been obtained for two additional solvents; namely, commercial hexane and a mixed solvent consisting of 85% by weight of acetone and 15% of hexane. Graphs have been constructed to show the effect of oil‐solvent ratio, chilling temperature, holding‐time, and agitation on the percentage of solid removed, the degree of winterization and the settling qualities of the solid separating.

These data, with those previously reported for acetone (1), afford a basis for the selection of the optimum conditions and procedures in the application of solvent winterization to cottonseed oil and bring out the relative advantages, disadvantages, and limitations of the three solvents. The acetone‐hexane mixture seems to combine the advantages and eliminate the disadvantages of either of these solvents alone.
Early Postoperative Oral Feeding Accelerates Upper Gastrointestinal Anastomotic Healing in the Rat Model
Authors: Fukuzawa Junya , Terashima Hideo , Ohkohchi Nobuhiro
Published: April 2007

Background

The benefits of early postoperative oral feeding following colonic anastomosis have previously been demonstrated. However, early postoperative oral feeding in patients with upper gastrointestinal surgery has been avoided because of concerns regarding anastomotic leakage. We investigated whether early postoperative oral feeding was advantageous for upper gastrointestinal anastomosis in comparison to parenteral feeding with a fasting period.

Materials and Methods

Male Sprague‐Dawley rats were subjected to the same surgical manipulation, i.e., venous catheterization, gastrostomy, and proximal jejunal anastomosis. Rats were divided into two groups: the enteral nutrition (EN) group, which received nutrients via gastrostomy as a substitute for oral feeding, and the total parental nutrition (TPN) group, which was fed via a venous catheter. Identical nutritional solutions were administered to the two groups immediately after surgery. The anastomotic bursting pressure (ABP) and the content of hydroxyproline in the anastomotic tissue were measured 5 days postoperatively.

Results

The ABP in the EN group was significantly higher than that in the TPN group (214.6 ± 42 versus 149.5 ± 49 mmHg; p < 0.01). The hydroxyproline content in the EN group was also significantly higher (63.5 ± 10 versus 50.5 ± 12 μmol/g dry tissue; p < 0.01).

Conclusions

Early enteral feeding via gastrostomy accelerated jejunal anastomotic healing in comparison to parenteral feeding. This study clearly indicates that early oral feeding after upper gastrointestinal surgery leads to prompt anastomotic healing.
Inter-observer reliability of the Stulberg classification in the assessment of Perthes disease
Authors: Wiig Ola , Terjesen Terje , Svenningsen Svein
Published: April 2007

Purpose

Accurate and reliable radiographic classifications are of great importance as a basis of treatment decisions and prognosis in Perthes disease. The classification of Stulberg is widely used as a predictor of long-term outcome. The aim of the present study was to determine whether the Stulberg classification is sufficiently reliable for routine clinical use in the assessment of Perthes disease.

Methods

We used this classification to assess the radiographs of 101 hips in two separate sessions (55 and 46 hips, respectively), interfered by an educational intervention in which the classification algorithm was discussed and clarified.

Results

We obtained good agreement between experienced examiners (weighted kappa 0.65) and a percentage agreement of 71%. We obtained weighted kappa values of 0.51 and 0.57 (moderate agreement) and percentage agreements of 62% and 65% between the least experienced observer and the two experienced examiners. Combining Stulberg class I and II, and IV and V into a simpler three-group classification gave better agreement between all observers. The agreement between the two experienced observers was improved to 81%.

Conclusions

We conclude that the reliability of the Stulberg classification is acceptable when the radiographic assessment is carried out by experienced examiners. A simpler three-group classification based on the shape of the femoral head (spherical, ovoid and flat) gave better agreement and is, therefore, recommended for routine clinical use.
Popularizing labor analgesia in China
Authors: Fan Zi Tian , Gao Xue Lian , Yang Hui Xia
Published: April 2007

In China many women in labor are young primigravidas whose fear of labor pain leads them to request cesarean deliveries. While the rate of cesarean deliveries has reached 50% in many hospitals, less than 1% of women in labor are given neuraxial analgesia. The necessary equipment is seldom available in China and many physicians have misconceptions about the risks associated with neuraxial analgesia, which are low with the ultra‐low‐dosages used today. However, attitudes have begun to change. Meetings held in China have brought together Chinese physicians and world experts on the various epidural and combined spinal‐epidural techniques. Thanks to the information and support provided at these meetings clinical trials were carried out, more than 5000 women benefited from labor analgesia, and publications appeared in Chinese journals. An effective, safe, and cost‐effective way to provide analgesia to women in labor may slow the increase in cesarean delivery rates across China and improve Women's health in general.
HPV‐related vulvar intraepithelial neoplasia: Outcome of different management modalities
Authors: Bruchim I. , Gotlieb W.H. , Mahmud S. , Tunitsky E. , Grzywacz K. , Ferenczy A.
Published: April 2007

Objective: To evaluate the outcome of various management schemes for HPV‐related vulvar intraepithelial neoplasia (VIN, usual type). Methods: Retrospective chart review of patients with histologically diagnosed grade 2/3‐VIN who had at least one year of follow‐up. The variables that were collected included patient characteristics, management modalities, and clinical outcome. Results: Fifty patients with a median age of 45 years old were evaluated. The median duration of follow‐up was 43.5 months (12–186). Complete response (CR) and partial response occurred in 28 (56%) and 4 (8%), respectively. Nineteen of 28 patients with CR recurred with VIN. Surgical excision yielded higher CR (77%) than did either ablational techniques (21–33%) or topical immunotherapy (33%). Conclusion: In this experience, surgical excision for VIN, usual type, resulted in better therapeutic success rates than other treatment modalities. Management schemes should be individualized based on extent of disease and patient compliance.
Inactivation-denaturation kinetics of bovine milk alkaline phosphatase during mild heating as determined by using a monoclonal antibody-based immunoassay
Authors: Levieux Didier , Geneix Nathalie , Levieux Annie
Published: April 2007

A monoclonal antibody based capture immunoassay has been recently developed for the specific quantitation of bovine milk alkaline phosphatase (ALP) without interference by contaminating microbial or fungal ALPs (Geneix et al. 2007). This immunoassay was used to study the kinetics of ALP heat denaturation in bovine milk over a range 50–60°C for 5 to 60 min using a colorimetric quantification of the enzyme activity as a reference test. A denaturation midpoint was obtained at 56°C for a 30 min heating. Thermal inactivation was found to follow first order kinetics and is characterized by z value of 6·7 deg C (D60°C=24·6 min) and 6·8 (D60°C=23·0 min) for respectively immunoassay and colorimetric assay. The high values of enthalpy of activation and the positive values of the entropy of activation and free energy of activation indicate that during denaturation ALP underwent a large change in conformation. The results of the immunoassay were highly correlated (r=0·994) with those obtained by the colorimetric assay. A similar high correlation (r=0·998) was obtained when industrially thermized milks (62–67°C for 20–90 s) were analysed by both techniques. These results indicated that 1) thermally induced epitopic structural changes recognized by the capture monoclonal antibody are concomitant with or occur after the loss of enzymatic activity and 2) quantification of ALP by the specific immunoassay is appropriate for determining mild time/temperature treatment of milk and for the control of milk pasteurization.
Immunology of pregnancy: cellular mechanisms allowing fetal survival within the maternal uterus
Authors: Zenclussen Ana Claudia , Schumacher Anne , Zenclussen Maria Laura , Wafula Paul , Volk Hans-Dieter
Published: April 2007

Pregnancy success remains a fascinating phenomenon to immunologists as it defies the immunological rules of rejection. Although it was previously thought that the maternal immune system does not see the fetus, it is now well documented that fetal cells reach the maternal body and encounter host immune cells. Natural tolerance mechanisms following this interaction remain to be fully elucidated. This article reviews the current literature on mechanisms of adaptive immunity, with emphasis on regulatory T cells and heme oxygenase 1 (HO-1). We propose a scenario in which regulatory T cells create a tolerant microenvironment at the fetal–maternal interface characterised by the presence of tolerance-associated molecules such as HO-1, which has been shown to be of vital importance for fetal survival.
Zur Frage nach einer genuinen Sozialpsychologie des Mediensports
Authors: Schramm Holger
Published: April 2007

Zusammenfassung: Der medialen Sportberichterstattung wird häufig vorgeworfen, die Sportrealität bzw. das reale Sportereignis nur verzerrt abzubilden und den Rezipierenden eine ganz eigene Mediensportrealität zu vermitteln. Die nahe liegende These lautet, dass sich das Erleben von Mediensport vom Erleben des entsprechenden nicht medial vermittelten Sports unterscheidet. Nun weisen einerseits Befunde aus der Sozialpsychologie des Sports in vielen Bereichen starke Parallelen zu entsprechenden Befunden zur Sozialpsychologie des Mediensports auf. Andererseits lassen sich aber zahlreiche sozialpsychologische Besonderheiten a) in der medialen Aufbereitung des Sports, b) in der medialen Rezeptionssituation sowie c) in der massenmedialen Öffentlichkeitswirkung identifizieren, die auf Unterschiede im Erleben von Sport und Mediensport hindeuten. Dieser Beitrag arbeitet diese Besonderheiten heraus und trägt Befunde zusammen, die eine genuine Sozialpsychologie des Mediensports - zumindest in Teilen - begründet.
Jammern oder Lösungsexploration?
Authors: Kauffeld Simone
Published: April 2007

Zusammenfassung. Gruppendiskussionen zur Bewältigung von Optimierungsaufgaben werden in Betrieben nicht nur genutzt, um Lösungsvorschläge zu explorieren, sondern es tauchen häufig Situationen auf, in denen gejammert wird. Eine Sequenzanalyse an Daten von 59 echten Gruppendiskussionen aus 19 Industrieunternehmen, die nach dem Kasseler-Kompetenz-Raster (KKR) ausgewertet wurden, zeigt, dass sich Jammern verhaltenserleichternd auf weitere Jammeräußerungen und verhaltenshemmend auf lösungsorientierte Äußerungen auswirkt. Lösungsorientierte Äußerungen hingegen ziehen lösungsorientierte und keine Jammeräußerungen nach sich. Durch zustimmende Äußerungen können sowohl Jammerzirkel als auch Lösungszirkel entstehen. Bezüglich des Unterbrechens von Jammern weisen die Ergebnisse auf die Bedeutung strukturierender Äußerungen hin. Die Befunde werden vor dem Hintergrund der kollektiven Konstruktion von Gruppenstimmungen und interpersonaler Theorien diskutiert. Praktische Implikationen der Ergebnisse werden aufgezeigt.
Methodik zur Ermittlung und Validierung von Anforderungen an Studierende (MEVAS)
Authors: Hell Benedikt , Ptok Claudia , Schuler Heinz
Published: April 2007

Zusammenfassung. Die vorliegende Arbeit stellt eine neuartige Methode zur Ermittlung und Validierung von Anforderungen an Studierende (MEVAS) vor. Aufbauend auf den Ergebnissen von Critical Incident Technique-Sitzungen werden in einem zweiten Schritt die ermittelten Einzelanforderungen von Hochschullehrern und Studierenden hinsichtlich der Bedeutsamkeit für ein erfolgreiches Studium und hinsichtlich des Erfüllungsgrads durch derzeit Studierende beurteilt. In einem dritten Schritt werden die Anforderungsdimensionen faktorenanalytisch verdichtet. Die bei den Studierenden festgestellten Erfolgskriterien erlebte Passung im Studium, Studienzufriedenheit, Studienverlaufsdaten und Noten im Vordiplom werden anschließend dazu herangezogen, die ermittelten Anforderungen zu validieren. Die Durchführung der MEVAS im Studiengang Wirtschaftswissenschaften erbringt 15 Anforderungsdimensionen. Die extrahierten Anforderungsdimensionen weisen ein differenzielles Validitätsprofil für verschiedene Studienerfolgskriterien auf. Für das Erfolgskriterium Durchschnittsnote im Vordiplom kann der selbst eingeschätzte individuelle Erfüllungsgrad der Anforderungsdimension Kognitive Leistungsfähigkeit inkrementell Varianz gegenüber dem Prädiktor Abiturdurchschnittsnote aufklären. Die MEVAS kann Grundlage für die Konstruktion von Auswahlverfahren sein und zur Studien- und Karriereberatung herangezogen werden.
Wirksamkeit und Langzeitstabilität von verhaltenstherapeutischen Interventionen bei Jugendlichen mit Zwangsstörungen
Authors: Döpfner Manfred , Breuer Ulla , Hastenrath Blanka , Goletz Hildegard
Published: April 2007

Zusammenfassung. Bei Kindern und Jugendlichen mit der Diagnose einer Zwangsstörung hat sich die multimodale verhaltenstherapeutische Behandlung als wirkungsvoll erwiesen. Zur mittel- und längerfristigen Stabilität der Behandlungseffekte liegen jedoch noch keine Studien vor. Diese Studie untersucht die Kurz- und Langzeiteffekte von Verhaltenstherapie bei10 bzw. 9 Patienten im Alter von 9 bis 19 Jahren. Die ambulante Therapie dauerte durchschnittlich 15 Monate einschließlich Nachbetreuung. Eine Nachuntersuchung wurde nach durchschnittlich 4.2 Jahren durchgeführt. Während der Therapie konnten die Zwangssymptomatik bei allen Patienten auf allen Parametern deutlich vermindert werden. Neben der Zwangssymptomatik konnten auch andere komorbide Störungen und die mit der Symptomatik einhergehenden Belastungen in der Familie, der Schule und der Freizeit deutlich vermindert und die soziale Funktionsfähigkeit erheblich verbessert werden. Diese Effekte erwiesen sich auf den meisten Variablen auch und bei den meisten Patienten noch mehr als vier Jahre nach Behandlungsende als stabil. Die Studie zeigt, dass durch Verhaltenstherapie eine langfristige Verbesserung der Zwangssymptomatik erreicht werden kann.
Emissions of gaseous mercury from biomass burning in South America in 2005 observed during CARIBIC flights
Authors: Ebinghaus R. , Slemr F. , Brenninkmeijer C. A. M. , van Velthoven P. , Zahn A. , Hermann M. , O'Sullivan D. A. , Oram D. E.
Published: April 2007

Plumes of biomass burning effluents were observed during CARIBIC flights between São Paulo and Santiago de Chile on August 31 and October 5, 2005, as well as during the last part of the flight from Frankfurt to São Paulo on October 4, 2005. Total gaseous mercury (TGM) correlated with CO on August 31 and October 4 yielding a TGM/CO emission ratio of (1.2 ± 0.2) × 10−7 and (2.4 ± 1.0) × 10−7 mol/mol, respectively. No significant TGM/CO correlation was observed on October 5 probably because of variable background concentrations of both gases. The TGM/CO emission ratios observed here over South America fall within the rather narrow range of (0.67–2.4) × 10−7 mol/mol reported hitherto for sites geographically as different as South Africa, Canada, and the U.S.A. A total average emission of 437 Tg CO/yr from biomass burning over the years 1996–2000 implies an average TGM emission of 210–750 t/yr from biomass burning, representing 3–11% of all mercury emissions. TGM emissions from biomass burning are likely to be larger than anthropogenic emissions in the southern hemisphere during the burning season in August–October.
Morphological features of ionospheric response to typhoon
Authors: Xiao Zuo , Xiao Sai‐guan , Hao Yong‐qiang , Zhang Dong‐he
Published: April 2007

Couplings between the ionosphere and meteorological events have been studied widely. However, most of them are individual case studies or correlation analyses, and few are aiming at the full morphological features of the ionospheric response processes. In this paper, complete records of 24 strong typhoons from 1987 to 1992 were collected, and comparison was made with corresponding ionospheric HF Doppler shift data. The main purpose of the present work is to find the temporal evolution of these responses and their common features by the merit of the continuities of HF Doppler shift observation in time. On the basis of the statistical analyses, this paper reveals the common features of ionospheric responses to typhoon. A summary of these characteristics is as follows: (1) During the existing time of a typhoon, there are almost always medium‐scale traveling ionospheric disturbances (TIDs) in the ionosphere, especially when a strong typhoon is landing or near the coast of a mainland. (2) These TIDs show quite clear periodicity and their periods vary with time and gradually grow longer. (3) After sunset, the wavelike disturbances with large magnitudes often excite the midlatitude spread‐F. (4) The intense typhoon can cause the wavelike records of the Doppler shift to show the S‐shaped echo tracing, which means that the amplitudes of those waves are sufficiently large, and (5) the sunrise‐like phenomena often appear in nonsunrise time during the period the typhoon exists. The phenomena mentioned above are generally in agreement with the linear propagation theories of the acoustic‐gravity waves (AGWs) in the atmosphere. A typhoon is surely one of the important ground sources of the wavelike disturbances in troposphere; this source is very effective especially when a typhoon is landing on or near a mainland coast. Of course, the morphological details of the ionospheric response to typhoon can by no means be completely identical every time. In this study, except for TIDs that almost always appear during all the typhoon events, the other common features are not seen every time. However, we are certain that the phenomena summarized above are statistically the manifestation of the ionospheric response to typhoon since they appear much more frequently during periods influenced by typhoon.
Breakdown of the frozen‐in condition in the Earth's magnetotail
Authors: Lui A. T. Y. , Zheng Y. , Rème H. , Dunlop M. W. , Gustafsson G. , Owen C. J.
Published: April 2007

We investigate in detail the breakdown of the frozen‐in condition detected by Cluster at the downstream distance of ∼19 RE in the midnight sector of the magnetotail during a substorm expansion on 22 August 2001. It is found that the breakdown occurred (1) in a low‐density environment with moderate to large proton plasma flow and significant fluctuations in electric and magnetic fields, (2) in regions with predominantly dissipation but occasionally dynamo effect, and (3) at times simultaneously at two Cluster satellites separated by more than 1000 km in both X‐ and Z‐directions. Evaluation of the terms in the generalized Ohm's law indicates that the anomalous resistivity contribution arising from field fluctuations during this event is the most significant, followed by the Hall, electron viscosity, and inertial contributions in descending order of importance. This result demonstrates for the first time from observations that anomalous resistivity from field fluctuations (implying kinetic instabilities) can play a substantial role in the breakdown of the frozen‐in condition in the magnetotail during substorm expansions. Consideration of several observed features in the breakdown regions indicates that the breakdown occurs in a turbulent site resembling observed features found in current disruption and dipolarization sites.
A Combination of Space and Terrestrial Geodetic Techniques to Monitor Land Subsidence: Case Study, the Southeastern Po Plain, Italy
Authors: Zerbini Susanna , Richter Bernd , Rocca Fabio , van Dam Tonie , Matonti Francesco
Published: April 2007

The southeastern Po Plain is affected by high natural and anthropogenic subsidence. The area is well suited to test the application of an observational strategy which combines different techniques to extract information on the spatial and temporal variability of the subsidence. The simultaneous availability, at a few stations, of several geodetic observation techniques such as Global Positioning System (GPS), gravity, and Interferometric Synthetic Aperture Radar (InSAR) allows for validation of the individual time series. The combination takes advantage of the complementary strengths of each technique by overcoming the limitations inherent in each single technique alone. The combination of velocities derived from the GPS and gravity data, further complemented by the results of the InSAR Permanent Scatterers technique, allows us to monitor continuously, in space and time, vertical crustal movements. This high‐density information is of major importance for understanding the processes responsible for the observed deformation. Here long‐term trends were derived, enabling us to map the behavior of subsidence (even exceeding 20 mm/yr) with high spatial resolution in the southeastern Po Plain. The uplifting behavior of the Apennines chain bordering the Po Plain is identified together with a narrow zone separating the contrasting vertical crustal movements.
Vertical cloud structure observed from shipborne radar and lidar: Midlatitude case study during the MR01/K02 cruise of the research vessel Mirai
Authors: Okamoto Hajime , Nishizawa Tomoaki , Takemura Toshihiko , Kumagai Hiroshi , Kuroiwa Hiroshi , Sugimoto Nobuo , Matsui Ichiro , Shimizu Atsushi , Emori Seita , Kamei Akihide , Nakajima Teruyuki
Published: April 2007

We observed the vertical distribution of clouds over the Pacific Ocean near Japan in May 2001 using lidar and a 95‐GHz radar on the Research Vessel Mirai. Cloud analyses derived from synergy use of radar and lidar observations showed that there were two local maxima of cirrus cloud frequency of occurrence at 7 and 10.5 km and the drizzle frequency of occurrence was about the half compared with that of clouds below 4 km. The number of layers could be also measured using these schemes. Single, double, triple, and quadruple (or more) cloud layers had a 48, 23, 7, and 2% probability of occurrence, respectively. The average number of cloud layers when clouds existed was 1.54. The vertical structure of clouds observed with the radar/lidar system was compared to clouds in the aerosol transport model SPRINTARS, which is based on the CCSR‐NIES Atmospheric General Circulation Model. The cloud fraction, radar reflectivity factor, and lidar backscattering coefficient were simulated by the model and compared to those by the observations using height‐time cross‐sections where the radar sensitivity was taken into account. The overall pattern of cloud fraction was well reproduced, although the model underestimated (overestimated) mean cloud fraction below 8 km (above 8 km). Cloud microphysics in the model could also be validated through comparison of derived model radar and lidar signals in grid mean with observations. The model overestimated ice particle size above 10 km, and simulated particle sizes in water clouds of 10 μm were larger than observed.
Laboratory sandbox validation of transient hydraulic tomography
Authors: Liu X. , Illman W. A. , Craig A. J. , Zhu J. , Yeh T.‐C. J.
Published: April 2007

Hydraulic tomography is a method that images the hydraulic heterogeneity of the subsurface through the inversion of multiple pumping or cross‐hole hydraulic test data. Transient hydraulic tomography is different from steady state hydraulic tomography in that it utilizes transient hydraulic head records to yield the distribution of hydraulic conductivity (K) as well as specific storage (Ss) of an aquifer. In this paper we demonstrate the robustness of transient hydraulic tomography through the use of hydraulic head data obtained from multiple cross‐hole pumping tests conducted in a laboratory sandbox with deterministic heterogeneity. We utilize the algorithm developed by Zhu and Yeh (2005) to conduct the transient inversions and validate the K and Ss tomograms using a multimethod and multiscale validation approach previously proposed by Illman et al. (2006). Validation data consist of cross‐hole tests not used in the inversion as well as other hydraulic tests that provided local (core, single‐hole tests) as well as large‐scale (unidirectional flow‐through tests) estimates of hydraulic parameters. Results show that the algorithm is able to yield consistent estimates that agree with independently collected local as well as large‐scale hydraulic parameter data. In addition, we find that the transient hydraulic tomography requires a fewer number of pumping tests to estimate a similar quality K tomogram when compared with steady state hydraulic tomography, as the former approach utilizes more data from each pumping test. Overall, we find that transient hydraulic tomography is a robust subsurface characterization technique that can delineate the subsurface heterogeneity in both K and Ss from multiple pumping or cross‐hole hydraulic tests.
Novel P2X7 receptor antagonists ease the pain
Authors: King B F
Published: April 2007

In recent months, a series of chemically diverse antagonists has been identified for the ATP‐gated P2X7 receptor. In particular, two classes of highly‐selective competitive P2X7 antagonists have been developed by Michael Jarvis and his colleagues at Abbott Laboratories. These di‐substituted tetrazole and cyanoguanidine derivatives are outstanding for a number of reasons (not least their stability, selectivity, potency and, of course, reversibility); most exciting is their near equal potency at human and rodent P2X7 isoforms. Armed with drugs such as A740003 and newer A438079, Jarvis and colleagues have explored the role of P2X7 receptors in the onset and persistence of chronic pain in animal models. Their findings ‐ and applicability to the human condition ‐ are reviewed in this current issue of British Journal of Pharmacology. This accompanying Commentary describes the progress made by Jarvis and others in developing novel P2X7 antagonists for pain relief.

British Journal of Pharmacology (2007) 151, 565–567; doi:10.1038/sj.bjp.0707266
Human INT6/eIF3e is required for nonsense‐mediated mRNA decay
Authors: Morris Christelle , Wittmann Jürgen , Jäck Hans‐Martin , Jalinot Pierre
Published: April 2007

The mammalian integration site 6 (INT6) protein has been implicated in breast carcinogenesis and characterized as the eIF3e non‐core subunit of the translation initiation factor eIF3, but its role in this complex is not known. Here, we show that INT6 knockdown by RNA interference strongly inhibits nonsense‐mediated messenger RNA decay (NMD), which triggers degradation of mRNAs with premature stop codons. In contrast to the eIF3b core subunit, which is required for both NMD and general translation, INT6 is only necessary for the former process. Consistent with such a role, immunoprecipitation experiments showed that INT6 co‐purifies with CBP80 and the NMD factor UPF2. In addition, several transcripts known to be upregulated by UPF1 or UPF2 depletion were also found to be sensitive to INT6 suppression. From these observations, we propose that INT6, in association with eIF3, is involved in routing specific mRNAs for degradation.
Structural plasticity in the oestrogen receptor ligand‐binding domain
Authors: Nettles Kendall W , Bruning John B , Gil German , O'Neill Erin E , Nowak Jason , Hughs Alun , Kim Younchang , DeSombre Eugene R , Dilis Robert , Hanson Robert N , Joachimiak Andrzej , Greene Geoffrey L
Published: April 2007

The steroid hormone receptors are characterized by binding to relatively rigid, inflexible endogenous steroid ligands. Other members of the nuclear receptor superfamily bind to conformationally flexible lipids and show a corresponding degree of elasticity in the ligand‐binding pocket. Here, we report the X‐ray crystal structure of the oestrogen receptor α (ERα) bound to an oestradiol derivative with a prosthetic group, ortho‐ trifluoromethlyphenylvinyl, which binds in a novel extended pocket in the ligand‐binding domain. Unlike ER antagonists with bulky side groups, this derivative is enclosed in the ligand‐binding pocket, and acts as a potent agonist. This work shows that steroid hormone receptors can interact with a wider array of pharmacophores than previously thought through structural plasticity in the ligand‐binding pocket.
Exploring the specificity of the PI3K family inhibitor LY294002
Authors: Gharbi Severine I. , Zvelebil Marketa J. , Shuttleworth Stephen J. , Hancox Tim , Saghir Nahid , Timms John F. , Waterfield Michael D.
Published: April 2007

The PI3Ks (phosphatidylinositol 3-kinases) regulate cellular signalling networks that are involved in processes linked to the survival, growth, proliferation, metabolism and specialized differentiated functions of cells. The subversion of this network is common in cancer and has also been linked to disorders of inflammation. The elucidation of the physiological function of PI3K has come from pharmacological studies, which use the enzyme inhibitors Wortmannin and LY294002, and from PI3K genetic knockout models of the effects of loss of PI3K function. Several reports have shown that LY294002 is not exclusively selective for the PI3Ks, and could in fact act on other lipid kinases and additional apparently unrelated proteins. Since this inhibitor still remains a drug of choice in numerous PI3K studies (over 500 in the last year), it is important to establish the precise specificity of this compound. We report here the use of a chemical proteomic strategy in which an analogue of LY294002, PI828, was immobilized onto epoxy-activated Sepharose beads. This affinity material was then used as a bait to fish-out potential protein targets from cellular extracts. Proteins with high affinity for immobilized PI828 were separated by one-dimensional gel electrophoresis and identified by liquid chromatography–tandem MS. The present study reveals that LY294002 not only binds to class I PI3Ks and other PI3K-related kinases, but also to novel targets seemingly unrelated to the PI3K family.
Functional domains and interdomain communication in Candida albicans glucosamine-6-phosphate synthase
Authors: Olchowy Jarosław , Gabriel Iwona , Milewski Sławomir
Published: April 2007

Functional and structural properties of several truncated or mutated variants of Candida albicans Gfa1p (glucosamine-6-phosphate synthase) were compared with those of the wild-type enzyme. Fragments encompassing residues 1–345 and 346–712 of Gfa1p, expressed heterogeneously in bacterial host as His6 fusions, were identified as the functional GAH (glutamine amidehydrolysing) and ISOM (hexose phosphate-isomerizing) domains respectively. It was found that the native GAH domain is monomeric, whereas the native ISOM domain forms tetramers, as does the whole enzyme. Spectrofluorimetric and kinetic studies of the isolated domains, the Δ218–283Gfa1p mutein and the wild-type enzyme revealed that the binding site for the feedback inhibitor, uridine 5′-diphospho-N-acetyl-D-glucosamine, is located in the ISOM domain. Inhibitor binding affects amidohydrolysing activity of the GAH domain and, as a consequence, the GlcN-6-P (D-glucosamine-6-phosphate)-synthetic activity of the whole enzyme. The fragment containing residues 218–283 is neither involved in ligand binding nor in protein oligomerization. Comparison of the catalytic activities of Gfa1pV711F, Δ709–712Gfa1p, Gfa1pW97F and Gfa1pW97G with those of the native Gfa1p and the isolated domains provided evidence for an intramolecular channel connecting the GAH and ISOM domains of Gfa1p. The channel becomes leaky upon deletion of amino acids 709–712 and in the W97F and W97G mutants. The Trp97 residue was found to function as a molecular gate, opening and closing the channel. The W97G and V711F mutations resulted in an almost complete elimination of the GlcN-6-P-synthetic activity, with the retention of the amidohydrolase and sugar phosphate-isomerizing activities.