2,303 research outputs found
Light-cone gravity in AdS
We obtain a closed form expression for the Action describing pure gravity, in
light-cone gauge, in a four-dimensional Anti de Sitter background. We perform a
perturbative expansion of this closed form result to extract the cubic
interaction vertex in this gauge.Comment: 11 page
School Psychologists Experiences with Assessment of Culturally and Linguistically Diverse Students
This qualitative research study responds to school psychologists’ experiences in assessment of culturally and linguistically diverse students. African Americans and other minority groups have been excessively represented in special education programs such as Mentally Retarded and Emotionally Disturbed Programs. English Language Learners have also been targeted and placed in special education programs unfairly due to culture and language. This research study used grounded theory approach in which several themes and sub-themes emerged regarding the serious problem of over-representation of minority students in special education. The themes and sub-themes included: Referrals (Behavior, Academic, Pre-referral); Materials (Tools); Culturally Competent (Reflection and Essence); Assessment (Students and Families); Over-representation (Bias Testing, Undetermined, Lack of skills, Language, Race/ethnicity, School culture/climate; and Roles (Duties). Based on this research study, which involved the recruitment of fifteen school psychologists (1 male and 14 female) the findings indicated the majority of school psychologists were not using all of the basic elements of a culturally competent assessment; therefore, their practices may be adding to the over-representation of minority students in special education programs
A Survey on Big Data, Hadoop and it’s Ecosystem
Now days, The 21st century is emphasized by a rapid and enormous change in the field of information technology. It is a non-separable part of our daily life and of multiple other industries like education, genetics, entertainment, science & technology, business etc. In this information age, a vast amount of data generation takes place. This vast amount of data is referred as Big Data. There is a number of challenges present in the Big Data such as capturing data, data analysis, searching of data, sharing of data, filtering of data etc. Today Big Data is applied in various fields like shopping websites such as Amazon, Flipkart, Social networking sites such as Twitter, Facebook, and so on. It is reviewed from some literature that, the Big data tends to use different analysis methods, like predictive analysis, user analysis etc. This paper represents the fact that, Big Data required an open source technology for operating and storing huge amount of data. This paper greatly emphasizes on Apache Hadoop, which has become dominant due to its applicability for processing of big data.Hadoop supports thousands of terabytes of data. Hadoop framework facilitates the analysis of big data and its processing methodologies as well as the structure of an ecosystem
Ovicidal effect of four plant extracts on the eggs of Corcyra cephalonica (Stainton)
Extracts from Four plants, leaves of Argemone mexicana Euphorbia tirucalli, Nerium oleander and cotyledons of Semecarpus ancardium tested against eggs of Corcyra cephalonica. In contact toxicity test of different concentration of plant extract i.e 1ml, 2ml, 3ml and 4ml were applied on the freshly laid eggs. The inhibition of egg hatching increased with increased in concentration of plant extracts. It was observed that at 4 ml concentration of chloroform extract of Argemone mexicana exhibited 60.02 % ovicidal action whereas at the same concentration cotyledons of Semecarpus anacardium, phylloclade of Euphorbia tirucalli, Nerium oleander exhibit 45.72%, 34.64%, 39.83% respectively
Improved genome editing in human cell lines using the CRISPR method
The Cas9/CRISPR system has become a popular choice for genome editing. In this system, binding of a single guide (sg) RNA to a cognate genomic sequence enables the Cas9 nuclease to induce a double-strand break at that locus. This break is next repaired by an error-prone mechanism, leading to mutation and gene disruption. In this study we describe a range of refinements of the method, including stable cell lines expressing Cas9, and a PCR based protocol for the generation of the sgRNA. We also describe a simple methodology that allows both elimination of Cas9 from cells after gene disruption and re-introduction of the disrupted gene. This advance enables easy assessment of the off target effects associated with gene disruption, as well as phenotype-based structure-function analysis. In our study, we used the Fan1 DNA repair gene as control in these experiments. Cas9/CRISPR-mediated Fan1 disruption occurred at frequencies of around 29%, and resulted in the anticipated spectrum of genotoxin hypersensitivity, which was rescued by re-introduction of Fan1
Experimental evidence for fast cluster formation of chain oxygen vacancies in YBa2Cu3O7-d being at the origin of the fishtail anomaly
We report on three different and complementary measurements, namely
magnetisation measurements, positron annihilation spectroscopy and NMR
measurements, which give evidence that the formation of oxygen vacancy clusters
is on the origin of the fishtail anomaly in YBa2Cu3O7-d. While in the case of
YBa2Cu3O7.0 the anomaly is intrinsically absent, it can be suppressed in the
optimally doped state where vacancies are present. We therefore conclude that
the single vacancies or point defects can not be responsible for this anomaly
but that clusters of oxygen vacancies are on its origin.Comment: 10 pages, 4 figures, submitted to PR
Randomised comparison of primary stent placement versus primary angioplasty followed by selective stent placement in patients with iliac-artery occlusive disease
Background Percutaneous transluminal angioplasty (PTA) is a safe, simple, and successful treatment for intermittent claudication caused by iliac-artery occlusive disease. Primary stent placement has been proposed as more effective than PTA. We compared the technical results and clinical outcomes of two treatment strategies-primary placement of a stent across the stenotic segment of the iliac artery, or primary PTA followed by selective stent placement when haemodynamic results were inadequate. Methods We randomly assigned 279 patients with intermittent claudication, recruited from departments of vascular surgery, either to direct stent placement (group I, n=143) or primary angioplasty (group II, n=136), with subsequent stent placement in case of a residual mean pressure gradient greater than 10 mm Hg across the treated site. The main inclusion criterion was intermittent claudication on the basis of iliac-artery stenosis of more than 50%, proven by angiography. All patients had a clinical assessment before intervention and at 3, 12, and 24 months. Clinical success was defined as improvement of at least one clinical category. Secondary endpoints were initial technical results, procedural complications, cumulative patency as assessed by duplex ultrasonography, and quality of life. Findings In group II, selective stent placement was done in 59 (43%) of the 136 patients. The mean follow-up was 9.3 months (range 3-24). Initial haemodynamic success and complication rates were 119 (81%) of 149 limbs and 6 (4%) of 143 limbs (group I) versus 103 (82%) of 126 limbs and 10 (7%) of 136 limbs (group II), respectively. Clinical success rates at 2 years were 29 (78%) of 37 patients and 26 (77%) of 34 patients in groups I and II, respectively (p=0.6); however, 43% and 35% of the patients, respectively, still had symptoms. Quality of life improved significantly after intervention (p Interpretation There were no substantial differences in technical results and clinical outcomes of the two treatment strategies both at short-term and long-term follow-up. Since angioplasty followed by selective stent placement is less expensive than direct placement of a stent, the former seems to be the treatment of choice for lifestyle-limiting intermittent claudication caused by iliac artery occlusive disease
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