4,715 research outputs found
Standard model explanation of a CDF dijet excess in Wjj
We demonstrate the recent observation of a peak in the dijet invariant mass
of the Wjj signal observed by the CDF Collaboration can be explained as the
same upward fluctuation observed by CDF in single-top-quark production. In
general, both t-channel and s-channel single-top-quark production produce
kinematically induced peaks in the dijet spectrum. Since CDF used a Monte Carlo
simulation to subtract the single-top backgrounds instead of data, a peak in
the dijet spectrum is expected. The D0 Collaboration has a small upward
fluctuation in their published t-channel data; and hence we predict they would
see at most a small peak in the dijet invariant mass spectrum of Wjj if they
follow the same procedure as CDF.Comment: 3 pg., 2 figs, revtex, minor clarifications, to appear in Phys. Rev.
Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging
This paper looks at some of the issues raised by Ogbuās work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education,
its links to the future and its measurable outcomes in terms of āsuccessā as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian
children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after āNine-Elevenā is the education of Muslim children. A consideration of this current situation throws Ogbuās identification of āautonomous minorityā into question. It is argued that a greater understanding of diverse needs has to be
accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the āriskā of failure and disenchantment
Biodiesel production from Cannabis sativa oil from Pakistan
The present study was appraised using response surface methodology for process optimization owing to strong interaction of reaction variables: NaOCH3 catalyst concentration (0.25ā1.50%), methanol/oil molar ratio (3:1ā9:1), reaction time (30ā90 min), and reaction temperature (45ā65Ā°C). The quadratic polynomial equation was determined using response surface methodology for predicting optimum methyl esters yield from Cannabis sativa oil. The analysis of variance results indicated that molar ratio and reaction temperature were the key factors that appreciably influence the yield of Cannabis sativa oil methyl esters. The significant (p < 0.0001) variable interaction between molar ratio Ć catalyst concentration and reaction time Ć molar ratio was observed, which mostly affect the Cannabis sativa oil methyl esters yield. The optimum Cannabis sativa oil methyl esters yield, i.e., 86.01% was gained at 53Ā°C reaction temperature, 7.5:1 methanol/oil molar ratio, 65 min reaction time, and 0.80% catalyst concentration. The results depicted a linear relationship between observed and predicted values. The residual analysis predicted the appropriateness of the central composite design. The Cannabis sativa oil methyl esters, analyzed by gas chromatography, elucidated six fatty acid methyl esters (linoleic, Ī±-linolenic, oleic, palmitic, stearic, and Ī³-linolenic acids). In addition, the fuel properties, such as kinematic viscosity at 40Ā°C; cetane number; acid value; flash point; cloud, pour, and cold filter plugging points; ash content; density; and sulphur content, of Cannabis sativa oil methyl esters were evaluated and discussed with reference to ASTM D 6751 and EU 14214 biodiesel specifications
Bacterial isolates from neutropenic febrile pediatric patients and their sensitivity patterns to antibiotics
Patients on cytotoxic therapy often develop neutropenia and fever. Our interest was to identify the common pathogens isolated from such patients and to study the sensitivity patterns of these organisms to the antibiotics used in their treatment. Thus, guidelines can be established by hospitals to identify which antibiotics can be used in the treatment of these patients when the results of cultures and sensitivities are not available. We conducted a retrospective study of neutropenic pediatrics presenting to AKUH from July, 1990 to June, 1996. A total of 153 isolates in 35 different patients were studied. Samples for culture were taken from the sites at risk. The majority of samples consisted of blood, stool, pus and urine. Twenty stool samples were also sent for microscopy. Malignancies were both hematological and non-hematological. Gram negatives were isolated in 52.9%, gram positives in 33.9% and parasites in 13.2%. Salmonella paratyphi B was the most commonly isolated organism, followed by Pseudomonas aeroginosa, Giardia lamblia was the most common parasite. Sensitivity patterns of these organisms to antibiotics studied showed that Escheria coli had the lowest sensitivity rate being only 40% sensitive to Aztreonam and 64% sensitive to Ofloxacillin. A comparison was made between our findings and those reported in literature, as well as the risk factors for developing neutropenia. A guide to management is also discussed
Complications of in-dwelling venous access devices: a single institution experience
Objective: To determine the complications of venous access devices (VADs) in cancer patients.SETTING: Retrospective study in a tertiary referral center with specialist hematology and oncology services.SUBJECTS: First one hundred consecutive patients who were implanted a VAD. All patients had an underlying cancer and the devices were inserted by the same surgeon. The duration of use of VADs and causes of their premature removal were noted.Results: One hundred VADs (55 port-a-caths and 45 Hickman\u27s lines) were inserted in a total of 89 patients over a 7.5 year period. Majority of patients had acute myeloid leukemia (22) gastrointestinal malignancies (20) breast cancer (19) and genito-urinary cancers (15). The mean duration of use was 110 days; 157 days for the port-a-cath and 53 days for the Hickman\u27s line. Nineteen devices (10 port-a-caths and 9 Hickman\u27s lines) had to be removed prematurely. Two Hickman\u27s lines got removed accidentally. The causes of premature removal included device failure (9), exist site infection (4), luminal infection (3) and tunnel infection (3).CONCLUSION: The mean duration of use and the complication rates are comparable with studies reported in the literature
A light-activated antimicrobial surface is active against bacterial, viral and fungal organisms
Evidence has shown that environmental surfaces play an important role in the transmission of nosocomial pathogens. Deploying antimicrobial surfaces in hospital wards could reduce the role environmental surfaces play as reservoirs for pathogens. Herein we show a significant reduction in viable counts of Staphylococcus epidermidis, Saccharomyces cerevisiae, and MS2 Bacteriophage after light treatment of a medical grade silicone incorporating crystal violet, methylene blue and 2ānm gold nanoparticles. Furthermore, a migration assay demonstrated that in the presence of light, growth of the fungus-like organism Pythium ultimum and the filamentous fungus Botrytis cinerea was inhibited. Atomic Force Microscopy showed significant alterations to the surface of S. epidermidis, and electron microscopy showed cellular aggregates connected by discrete surface linkages. We have therefore demonstrated that the embedded surface has a broad antimicrobial activity under white light and that the surface treatment causes bacterial envelope damage and cell aggregation
Discrimination of sonographically detected breast masses using frequency shift color Doppler imaging in combination with age and gray scale criteria.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135358/1/jum2001204343.pd
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