Electron energy loss near edge structure on the nitrogen K-edge in vanadium nitrides

This paper presents electron energy-loss near-edge structure (ELNES) data for the N K edges of vanadium nitrides. By rapid thermal processing of vanadium layers in pure nitrogen at high temperatures the two known vanadium nitrides, VN and V₂N, have been prepared. The phases have been checked by electron diffraction and quantitative electron energy-loss spectroscopy (EELS) analysis. Because their crystallographical structures are different, they also exhibit different ELNES features, which can be used as fingerprints for rapidly distinguishing between VN and V₂N. The experimental findings are supported by modelling the N K edge using a band structure approach (full linearized augmented plane wave method).     

Recognition memory impairment in Parkinson's disease: Power and meta-analyses.

Contrary findings notwithstanding, the prevailing notion is that recognition memory is little affected by Parkinson's disease (PD). Both a power analysis and a meta-analysis were conducted to help clarify the degree of recognition memory deficit associated with PD. The power analysis confirmed that, in general, memory studies of PD participants have been underpowered. This analysis indicated the need to pool study results in a subsequent meta-analysis, the main finding of which was that recognition memory deficits do occur with PD. The largest deficit occurs in PD participants with dementia. Nevertheless, deficits also occur in PD participants without dementia on medication, but nondopaminergic central nervous system abnormalities are more likely to underlie this deficit than PD medication itself. Future development of a theory of cognitive dysfunction in PD should take into account these recognition memory deficits, which may increase with disease progression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socially mediated reduction of isolation distress in rat pups is blocked by naltrexone but not by Ro 15-1788.

[Correction Notice: An erratum for this article was reported in Vol 104(4) of Behavioral Neuroscience (see record 2008-10515-001). On page 462, the last paragraph of the first column was incorrect. The corrected paragraph is provided in the erratum.] The presence of a single anesthetized littermate significantly reduced the rate of ultrasonic vocalization by 10-day-old pups isolated in a novel environment. Naltrexone (1.0 mg/kg) returned the vocalization rate to the level of pups tested alone and disrupted the maintenance of body contact between the test pup and a companion. This suggests that the companion exerts comforting effects through endogenous opioid mechanisms. Although chlordiazepoxide is as effective as morphine in the quieting of isolation distress, the benzodiazepine (BDZ) antagonist Ro 15-1788 (5, 10, or 20 mg/kg) was ineffective in blocking the comfort effect and facilitated quiet contact with the companion. In isolated pups, Ro 15-1788 caused a significant, but not a dose-related, decrease in vocalization, a possible indication of the displacement of an endogenous anxiogenic ligand at the BDZ receptor complex. [An erratum for this article will appear in Behavioral Neuroscience, 1990 (Aug), Vol 104:4. The erratum concerns an error in the last paragraph of the first column on page 462.] (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Entwicklung einer SOA-basierten Webanwendung zur Buchung und Verwaltung von Segeltouren: Proprietäre Software vs. Open Source

Ohne Zusammenfassung Zuschriften zum Studierendenforum bitte an: Universit?t Bayreuth, Lehrstuhl BWL VII (Wirtschaftsinformatik), Prof. Dr. Torsten Eymann, Redaktion Studierendenforum, z. Hd. Dipl.-Wirtschaftsinformatiker Stefan K?nig, Universit?tsstra?e 30, 95447 Bayreuth, stefan.koenig@uni-bayreuth.de     

Source-monitoring training facilitates preschoolers' eyewitness memory performance.

Preschool children are more susceptible to misleading postevent information than are older children and adults. One reason for young children's suggestibility is their failure to monitor the source of their memories, as in, for example, discriminating whether an event was seen live versus on television. The authors investigated whether source-monitoring training would decrease preschoolers' suggestibility. Thirty-six 3-4-year-olds observed target live and video events and were then given source-monitoring or recognition (control) training on nontarget events. Following training, all children answered 24 misleading and nonmisleading target-event questions. Children given source-monitoring training were more accurate than control group children in response to misleading and nonmisleading yes-no questions and in response to nonmisleading, open-ended questions. Implications for strategy development, dual representation, and child witness interviewing are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aflatoxin and PAH exposure biomarkers in a U.S. population with a high incidence of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is significantly elevated in a Hispanic community in Bexar County, Texas. Chronic exposure to dietary aflatoxins (AFs) is a major risk factor for HCC; increased risk has been linked to polycyclic aromatic hydrocarbon (PAH) co-exposure and hepatitis virus infection. The aims of this study were to assess AF and PAH exposures, investigate dietary factors that may contribute to increased AF exposure, and determine the prevalence of hepatitis virus infection in Bexar Co. Blood and urine samples were collected from 184 volunteers for biomarker analyses and hepatitis screening. Serum AFB₁-lysine adduct, urinary AFM₁ and 1-hydroxypyrene (1-OHP) levels were measured using high-performance liquid chromatography. The average AFB₁-lysine adduct level detected in 20.6% of serums was 3.84 ± 3.11 pg/mg albumin (range 1.01-16.57 pg/mg). AFM₁ was detected in 11.7% of urines, averaging 223.85 ± 250.56 pg/mg creatinine (range 1.89-935.49 pg/mg). AFM₁ detection was associated with increased consumption of corn tortillas (p = 0.009), nuts (p = 0.033) and rice (p = 0.037). A significant difference was observed between mean 1-OHP values of non-smokers (0.07 ± 0.13) and smokers (0.80 ± 0.68) μmol/mol creatinine (p < 0.01). A high hepatitis C virus positivity rate (7.1%) was observed. Findings suggest that the incidence and level of AF and PAH exposure were less than those observed in a high-risk population; however, participants consuming higher amounts of foods prone to AF contamination may be more vulnerable to exposure and interactions with other environmental/biological factors (i.e., HCV).     

A Mutant D‐Fructose‐6‐Phosphate Aldolase (Ala129Ser) with Improved Affinity towards Dihydroxyacetone for the Synthesis of Polyhydroxylated Compounds

A mutant of D ‐fructose‐6‐phosphate aldolase (FSA) of Escherichia coli, FSA A129S, with improved catalytic efficiency towards dihydroxyacetone (DHA), the donor substrate in aldol addition reactions, was explored for synthetic applications. The k_cat/K_M value for DHA was 17‐fold higher with FSA A129S than that with FSA wild type (FSA wt). On the other hand, for hydroxyacetone as donor substrate FSA A129S was found to be 3.5‐fold less efficient than FSA wt. Furthermore, FSA A129S also accepted glycolaldehyde (GA) as donor substrate with 3.3‐fold lower affinity than FSA wt. This differential selectivity of both FSA wt and FSA A129S for GA makes them complementary biocatalysts allowing a control over donor and acceptor roles, which is particularly useful in carboligation multi‐step cascade synthesis of polyhydroxylated complex compounds. Production of the mutant protein was also improved for its convenient use in synthesis. Several carbohydrates and nitrocyclitols were efficiently prepared, demonstrating the versatile potential of FSA A129S as biocatalyst in organic synthesis.     

Enzymatic determination of sorbic acid

 An enzymatic method for the determination of sorbic acid based on the spectrophotometric measurement of sorbyl coenzyme A (sorbyl CoA) at 300 nm was developed. Sorbic acid is converted to sorbyl CoA with acyl CoA synthetase (EC 6.2.1.3) in the presence of coenzyme A and adenosine-5′-triphosphate. The reaction is made quantitative by irreversibly hydrolyzing pyrophosphate formed during the acylation reaction to phosphate in the presence of inorganic pyrophosphatase (EC 3.6.1.1). The absorbance measured at 300 nm is specific for sorbyl CoA and its value is proportional to the amount of sorbic acid in the sample solution. Accuracy, repeatability and recovery rates after standard addition to sample solutions were evaluated. All steps of the enzymatic analysis were carried out on an automatic centrifugal analyzer. The method is fast, precise and reliable, and therefore well suited for routine determinations, especially for high sample throughputs. Received: 7 June 1999 / Revised version: 12 August 1999     

Dialysis patients treated with Epoetin α show improved exercise tolerance and physical function: A new analysis of the Canadian Erythropoietin Study Group trial

The risks/benefits of anemia treatment in dialysis patients have been redefined in the US Epoetin α label. This analysis was carried out to determine if increasing hemoglobin (Hb) levels improve exercise tolerance and physical function in anemic dialysis patients. This is a new analysis of the Canadian Erythropoietin Study Group trial, a double‐blind, randomized, placebo‐controlled trial in dialysis patients. Subjects were 18 to 75 years old, on hemodialysis for >3 months, and had a baseline Hb <9.0 g/dL. Patients with a history of diabetes mellitus, ischemic heart disease, or severe/uncontrolled hypertension were excluded. Patients were randomized to receive Epoetin α to a target Hb of 9.5 to 11.0 g/dL (n=40) or a target of 11.5 to 13.0 g/dL (n=38), or receive placebo (n=40). Results from patients in the Epoetin‐α–treated arms were combined for this analysis. Hb level, exercise tolerance (Treadmill Stress Test and 6‐Minute Walk Test) and patient‐reported physical function measures (Physical Summary domain from the Kidney Disease Questionnaire, and 4 domains from the Sickness Impact Profile) were reported at baseline and months 2, 4, and 6. Differences in measures were statistically significant for exercise tolerance (Treadmill Stress, P=0.0001) and patient‐reported physical function (Kidney Disease Questionnaire Physical, P=0.0001; Sickness Impact Profile Physical, P=0.0015) across all time points for Epoetin‐α–treated patients compared with placebo. Improvements were seen at 2 months and were maintained through months 4 and 6. Dialysis patients receiving Epoetin α showed improved exercise tolerance and physical function. These findings should be considered as physicians weigh the risks and benefits of treatment.     

Defect cluster recognition system for fabricated semiconductor wafers

The International Technology Roadmap for Semiconductors (ITRS) identifies production test data as an essential element in improving design and technology in the manufacturing process feedback loop. One of the observations made from the high-volume production test data is that dies that fail due to a systematic failure have a tendency to form certain unique patterns that manifest as defect clusters at the wafer level. Identifying and categorising such clusters is a crucial step towards manufacturing yield improvement and implementation of real-time statistical process control. Addressing the semiconductor industry’s needs, this research proposes an automatic defect cluster recognition system for semiconductor wafers that achieves up to 95% accuracy (depending on the product type).