63 research outputs found
Persistence in STEM: Development of a Persistence Model Integrating Self-efficacy, Outcome Expectations and Performance in Chemistry Gateway Courses
STEM persistence has been an important issue, especially in the context of underrepresented groups based on race and gender. Researchers in the last decade or so have been examining the powerful impact that affective and cognitive factors can exert individually on performance and persistence. It is only reasonable to hypothesize that combining affective and cognitive measures would offer a more thorough understanding of factors that impact students’ performance and STEM persistence. Evaluating these outcomes in the context of gateway courses is particularly essential due to the non-negligible percentage of students who drop out of these courses or decide to change their intended STEM majors after key testing events.
Using social cognitive career theory (SCCT) as a framework, this exploratory study set out to develop / adapt surveys to capture two key SCCT constructs – self-efficacy (SE) and outcome expectations (OE). These surveys were psychometrically tested and used in the development of cross-sectional predictive performance and persistence models for general chemistry. Items from both full-length surveys were subsequently used in the development of a shortened survey, which was administered as key points during a semester to evaluate changes in performance, SE or OE prior to or after testing events. Interventions, packaged as study tools, were also administered to students before these events; the impact of these study tools on students’ SE, OE and performance was also assessed in efforts to assemble preliminary profiles for at-risk students
Developing the Computational Building Blocks for General Intelligent in SOAR
Cognitive architecture's purpose is to generate artificial agents with capacities similar to the human mind. Soar Cognitive Architecture is to produce the fixed computational building blocks needed for generally intelligent agents— agents that can outright a variety of tasks and encode, use, and learn all types of knowledge to realize the broad cognitive abilities present in humans. This paper introduced an arithmetic agent that does multicolumn, two-digit addition in SOAR. Here, we show the entire calculating procedure, including all of its operators. We are using episodic memory assistance to enhance the set of cognitive abilities that let the agent learn and reason
SYNTHESIS AND CRYSTAL STRUCTURE ANALYSIS OF 3 - (4 - METHOXYBENZYL) - 2, 3 – DIHYDRO - 4H – CHROMAN – 4 - ONE
3-(4-methoxybenzyl)-2,3-dihydro-4H-chroman-4-one(C17H16 O3) was synthesized by refluxing 2'-Hydroxydihydrochalcone dissolved in ethanol with paraformaldehyde and 50% aqueous diethylamine. The compound is characterized by IR,1HNMR, MS and X-ray diffraction studies. The X-ray structure analysis indicates that the crystal suffers from the positional disorder over two positions, atomC1 and C9 with required site occupancies of 0.590 and 0.410 leading to a conformational difference between the major and minor components. After applying similarity restraints, the final reliability index is 0.0275 for 2209 unique reflections .The crystal packing is stabilized by inter molecular C-H…O, C-H…π and π …π interactions
Clinical Assessment of Electromagnetic Compatibility of Hearing Aids and Digital Wireless Phones
Research studies have shown that digital wireless phones interact with some hearing aids, creating a buzzing noise that may reduce speech intelligibility. Interference signals for three phone technologies were generated at five sound pressure levels (35 dB, 45 dB, 55 dB, 65 dB, and 75 dB) and mixed with speech at 65 dB SPL to test the speech intelligibility of 24 hearing-impaired people. A “No Noise” condition was also tested. Scores for the TDMA-217 Hz phone signal at low speech-to-noise ratios (<10 dB) were significantly lower than those for CDMA and TDMA-50 Hz at the same level. The CDMA and TDMA-50 Hz phone signals had a similar effect on speech intelligibility. Speech intelligibility scores at speech-to-noise ratios of 20 dB and 30 dB were similar to those for the “No Noise” condition. The articulation index represented the best index for predicting the impact of wireless phone interference on speech intelligibility.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
BIODIESEL PRODUCTION FROM WASTE ANIMAL FAT USING A NOVEL CATALYST HCA IMMOBILIZED AuNPS AMINE GRAFTED SBA-15
The fleshings produced during the pre-tanning process in tanneries and animal wastes generated from slaughterhouse are causing serious environmental concern because of improper disposal techniques. The fats extracted from these wastes were used as feedstock for the production of biodiesel, which serves as an alternate for conventional diesel fuel because of their sustainability. The use of these animal fats ruled out the issues over the “food vs. fuel” conflict, as edible feedstocks were used in the production of biodiesel earlier. This work deals with the production of biodiesel from waste animal fats by the means of methanolbased transesterification using nanoparticles as a heterogeneous catalyst. A maximum fat recovery of 85% was achieved by the means of autoclave heat treatment method. The refining of fat was carried out through acid degumming, where orthophosphoric acid was mixed with the fat to remove the phospholipids as residues. Pretreatment of the extracted fat was done using glycerolysis, where the FFA % of these fats was reduced from 7% to 0.25% with a recorded efficiency of 96.4%. N catalyzed transesterification was carried out by investigating various operating parameters like oil/alcohol molar ratio, catalyst concentration, temperature and reaction time and optimizing them. The optimized process parameters produced a maximum yield of 94% biodiesel. The synthesized novel catalyst - HCA immobilized AuNPS AMINE grafted SBA-15 was characterized using spectral data. Besides, the residual glycerol is defined as a value-added product to meet its application in the glycerolysis process as a reactant
Intrahepatic Sarcomatoid Cholangiocarcinoma
Intrahepatic sarcomatoid cholangiocarcinoma is a rare but an aggressive variant of cholangiocarcinoma with a very poor prognosis. We report the first caucasian patient who presented with a rapidly enlarging liver mass requiring hepatic resection. Detailed histopathological analyses including immunohistochemistry and electron microscopy confirmed sarcomatoid cholangiocarcinoma. The patient had early onset disease recurrence within 5 weeks of surgery. Here we demonstrate that combination chemotherapy with gemcitabine and cisplatin is a potential treatment option in patients with advanced sarcomatous cholangiocarcinoma. The patient achieved sustained partial remission with combination chemotherapy and remains alive and well more than 29 months since initial surgery
Palladium-based ferroelectrics and multiferroics : theory and experiment
Palladium normally does not easily substitute for Ti or Zr in perovskite oxides. Moreover, Pd is not normally magnetic (but becomes ferromagnetic under applied uniaxial stress or electric fields). Despite these two great obstacles, we have succeeded in fabricating lead zirconate titanate with 30% Pd substitution. For 20:80 Zr:Ti the ceramics are generally single-phase perovskite (>99%), but sometimes exhibit 1% PbPdO2, which is magnetic below T=90K. The resulting material is multiferroic (ferroelectric-ferromagnet) at room temperature. The processing is slightly unusual (>8 hrs in high-energy ball-milling in Zr balls), and the density functional theory provided shows that it occurs because of Pd+4 in the oversized Pb+2 site; if all Pd+4 were to go into the Ti+4 perovskite B-site, no magnetism would result.PostprintPeer reviewe
Sirtuin 6 inhibition protects against glucocorticoid-induced skeletal muscle atrophy by regulating IGF/PI3K/AKT signaling
Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.Fil: Mishra, Sneha. No especifĂca;Fil: Cosentino, Claudia. Harvard Medical School; Estados UnidosFil: Tamta, Ankit Kumar. No especifĂca;Fil: Khan, Danish. No especifĂca;Fil: Srinivasan, Shalini. No especifĂca;Fil: Ravi, Venkatraman. No especifĂca;Fil: Abbotto, Elena. UniversitĂ degli Studi di Genova; ItaliaFil: Arathi, Bangalore Prabhashankar. No especifĂca;Fil: Kumar, Shweta. No especifĂca;Fil: Jain, Aditi. No especifĂca;Fil: Ramaian, Anand S.. No especifĂca;Fil: Kizkekra, Shruti M.. No especifĂca;Fil: Rajagopal, Raksha. No especifĂca;Fil: Rao, Swathi. No especifĂca;Fil: Krishna, Swati. No especifĂca;Fil: Asirvatham Jeyaraj, Ninitha. Indian Institute of Technology; IndiaFil: Haggerty, Elizabeth R.. Harvard Medical School; Estados UnidosFil: Silberman, Dafne MagalĂ. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Centro de Estudios FarmacolĂłgicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios FarmacolĂłgicos y Botánicos; ArgentinaFil: Kurland, Irwin J.. No especifĂca;Fil: Veeranna, Ravindra P.. No especifĂca;Fil: Jayavelu, Tamilselvan. No especifĂca;Fil: Bruzzone, Santina. UniversitĂ degli Studi di Genova; ItaliaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Sundaresan, Nagalingam R.. No especifĂca
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