8,111 research outputs found
Implications of the Improvement of Teaching Quality for Professional Development (PD) of Academics at the Colleges of Applied Sciences (CASs) in the Sultanate of Oman
No full textThe Oman Accreditation Council (OAC), which is called later the Oman Academic Accreditation Authority (OAAA), designed a higher education institution (HEI) Quality Assurance (QA) framework for Omani public and private Higher Education Institutions (HEIs), starting with a quality audit process in 2008. The Colleges of Applied Sciences (CASs), as a public HEI, are required to ensure the quality of all services and activities to meet particular national standards (specified in the framework) in order to gain a HEI and programme certificate. In line with a quality audit scope, the quality of the fields of PD and related teaching quality should be ensured and enhanced by the promotion and contribution of the former field to the maintenance and improvement of the latter one.
The chief purpose of this study was to identify the uptake and implications of the growing requirement to improve teaching quality and the PD of academics at the CASs in the Sultanate of Oman especially in the context of the application of the QA framework. The study focused on examining the academics’ participation in professional development programmes (PDPs) and current perceptions of PD with respect to the improvement of teaching quality improvement at these colleges. The current study also dealt with a reorganization and prioritization of academics’ PD needs, barriers to effective PD, and factors to enhance PD of academics regarding teaching quality improvement in the colleges.
Based on the purpose and research objectives, the current study adopted both positivist (quantitative) and interpretive (qualitative) research paradigms. Because the study perused quantitative and qualitative data regarding certain variables, it chose a mixed-research design. The researcher designed survey questionnaire to collect quantitative data and a semi-structured interview and a focus group discussion to probe and interpret quantitative findings. After fulfillment of the validity and reliability measurements, a self-completion questionnaire was distributed to a stratified random sample of academics (170) over the six CASs. A total of 150 questionnaires (out of 170) were completed and returned and the response-rate reached 88.2%. The quantitative data was analyzed by appropriate analysis using the Statistical Package for Social sciences (SPSS), while the qualitative data was analyzed by appropriate qualitative analysis.
The findings of the study showed that the level of academics’ participation in PDPs to improve teaching quality in the last two years in the CASs seems to be unsatisfactorily low. The current perceptions of the PD situations in the colleges, relating to teaching quality improvement, signified a shortage in the number of available PDPs and/or a discouragement of academics’ participation in these programmes in the last two years. The study also revealed all the 22 PD needs of academics regarding the improvement of teaching quality are significantly demanded by participants; the higher rated needs focused on a development of ‘student centred’ skills, such as critical thinking and problem-solving skills.
Furthermore, the study illustrated that the highest significant perceived barriers to effective PD in the CASs, as related to teaching quality improvement, focus on a lack of a clear institutional PD policy and a lack of appropriately systematic PD plans. The study also revealed all 10 perceived factors to enhance PD regarding teaching quality improvement are very important. The most significant factors represented and stressed particular problematic issues (the high rated barriers) and a reduction of a heavy workload to enhance academics’ participation in PD regarding the improvement of teaching quality.
Conclusions drawn from the discussion of the findings of study include a lack of a clear PD policy at national and institutional levels and absence of a particular authority/unit concerning PD issues in Omani HEIs. The two problematic issues resulted in a lack of systematic and realistic PD plans in the CASs, involving a lack of academics’ involvement in PD plans, a misconnection of academics’ PD needs to PD, inappropriate facilities and resources allocation, and inappropriate evaluation processes of PD. In addition, the conclusions also include that PD of academics regarding the improvement of teaching quality in the colleges requires more attention and focus to manage particular significant issues perceived by participants as both barriers and potential facilitators relating to PD of academics.
Based on identified conclusions, particular implications for policy and practice to enhance PD to improve teaching quality were set at three levels: governmental, institutional, and individual. Moreover, achievements of the current study according to the research questions were identified and contributions of the study to the fields of PD, teaching quality, and the context of QA and quality audit in HE were addressed. Based on the findings and conclusions, particular directions and recommended issues were suggested to be studied by further research to benefit the enhancement of PD and related teaching quality improvement
Fullerene-like WS<sub>2</sub> supported Pd catalyst for hydrogen evolution reaction
No full textHydrogen is the most desirable green energy carrier and electrocatalytic hydrogen evolution reaction (HER) from water is a promising route for hydrogen production. The search for efficient, low-cost HER catalysts is a challenging and attracting topic. In this work, we report that inorganic fullerene-like WS2 supported Pd nanoparticles (Pd/WS2), with Pd loading of 0.76 wt%, are active for electrocatalytic HER conducted in 0.5 M H2SO4 solution, with overpotential at 10 mA cm−2 current density of ~130 mV and Tafel slope of 82.4 mV dec−1, which is comparable to that of Pt/WS2 (0.88 wt% Pt loading) with higher costs. Characteristic results indicate that WO3 impurities were in-situ produced on the WS2 surface and the Pd NPs are primarily located inside the WS2 nanocages. Contrasting experiments suggest that the WO3 impurities play a crucial role in generating Hads intermediate and the Pd NPs are active sites of H2 production, and a reaction mechanism is proposed. The Pd/WS2 catalyst also shows good long-term stability owing to the location of Pd NPs inside the WS2 cages. The high HER activity, low costs and good stability make the Pd catalyst a potential alternative to Pt catalyst for HER.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Micro and Nano Engineerin
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The decay of Pd¹⁰⁹, Pd¹¹¹ [superscript g], and Pd¹¹¹ [superscript m]
No full textThe decay of Pd¹⁰⁹, Pd¹¹¹ [superscript g], and Pd¹¹¹ [superscript m] produced by thermal neutron irradiation of palladium targets has been investigated. Gamma ray energies and relative intensities have been measured with a high resolution Ge(Li) spectrometer. From energy sums and relative intensity considerations level schemes for Ag ¹⁰⁹ and Ag¹¹¹ are constructed. On the basis of beta and gamma selection rules, spin-parity assignments are made for the levels of Ag ¹⁰⁹ and Ag¹¹¹ The results of this study are compared with recent theoretical calculations
Cognitive deficits and structural brain changes associated with dementia and visual hallucinations in Parkinson's disease
No full text[eng] Cognitive impairment of different degrees and hallucinations are common complications of chronic Parkinson's disease (PD). The pathogenesis, pathophysiology, and relationship between cognitive deficits and presence of hallucinations are not fully understood but both impact severely on overall disability and quality of life of PD patients . Cognitive impairment and dementia are the most frequently reported risk factors for visual hallucinations (VH) in PD. Similarly, most studies have found a greater prevalence of psychosis in demented versus non-demented patients with PD. However, although the relationship between VH and cognitive dysfunction is well established, it seems that the emergence of visual hallucinations is not caused directly by the presence of general cognitive impairment because not all PD patients with dementia experienced VH and association studies reported several risk factors for the development of this symptom supporting a multicausal nature of this phenomenon. The data presented in this dissertation intend to give some clues towards a better understanding of the cerebral basis and neuropsychological deficits associated with dementia and visual hallucinations in Parkinson's disease patients. The general aims of this thesis were: 1)To study in vivo structural brain changes associated with dementia and visual hallucinations in Parkinson's disease patients. 2)To cognitively characterize a group of non-demented PD patients with VH in a cross-sectional and longitudinal study. For this purpose, we carried out five studies examining cognitive functions and structural brain characteristics in PD patients using neuropsychological and MRI methods. The first and the second investigations evaluated a sample of PD patients with and without dementia. The three last studies were carried out with non-demented PD patients with and without visual hallucinations. The results showed that the the pattern of cerebral atrophy found in demented PD and PD patients with VH extends well beyond the frontostriatal circuits traditionally described to be reponsible for cognitive symptoms in PD. We found grey matter atrophic changes affecting temporal and occipital regions in demented PD patients and in nondemented hallucinating PD patients. These findings stress the importance of the posterior cortical structures in the presence of cognitive impairment and VH in PD patients. We also observed a close relationship between the presence of hallucinations and progressive neuropsychological impairment. The cognitive impairments in hallucinating PD patients were observed in complex visual functions (visuoperceptive-visuospatial skills and visual memory) as well as semantic processing (such as interpretation of perceptual information). This neuropsychological pattern is in agreement with the atrophic changes found in our MRI study. The gray matter volume reductions involved not only secondary visual association areas but also tertiary areas implicated in the integration of semantic information.[spa] La enfermedad de Parkinson (EP) es un trastorno neurodegenerativo que se caracteriza por síntomas motores y no motores. Entre los síntomas no motores, la presencia de deterioro cognitivo y de síntomas psicóticos, concretamente alucinaciones se sitúan entre las complicaciones mas prevalentes. Ambas complicaciones tienen un gran impacto en el grado de incapacidad que sufre el paciente y por ende en su calidad de vida. La presencia de deterioro cognitivo y demencia se han identificado como los factores de riesgo mas frecuentemente asociados con el desarrollo de alucinaciones visuales (AV) en la EP. Asimismo, la mayoría de estudios han encontrado una mayor prevalencia de psicosis en pacientes con EP dementes respecto a los no dementes. Sin embargo, aunque la relación entre AV y disfunción cognitiva esta bien establecida, parece que la emergencia de AV no está causada directamente por la presencia de deterioro cognitivo pues no todos los pacientes con demencia experimentan AV y estudios de asociación apoyan una naturaleza multifactorial del fenómeno. El propósito general de esta tesis era lograr un mejor entendimiento de la base cerebral y de los déficits neuropsicológicos asociados a la presencia de demencia y AV en la EP. Los objetivos generales de los estudios que conformaron esta tesis fueron los siguientes: 1) Estudio de los cambios estructurales cerebrales asociados a la presencia de demencia y alucinaciones visuales en la enfermedad de Parkinson. 2) Caracterización cognitiva a través de un estudio transversal y de seguimiento a un grupo de pacientes con EP no dementes los cuales presentaban historia de alucinaciones visuales complejas. Para llevar a cabo estos objetivos fueron diseñados cinco estudios los que examinaron funciones cognitivas y características cerebrales estructurales en pacientes con EP utilizando para ello tests neuropsicológicos estandarizados y diferentes técnicas de resonancia magnética estructural. El primer y el segundo estudio evaluaron una muestra de pacientes con EP con y sin demencia. Los tres siguientes estudios fueron llevados a cabo en un grupo de pacientes con EP no dementes los cuales presentaban historia de AV complejas. Los resultados mostraron que el patrón de cambios estructurales cerebrales en pacientes con EP y demencia se extendía más allá de los circuitos fronto-estriatales descritos clásicamente como responsables de los déficits cognitivos de la EP. Fueron hallados cambios atroficos afectando a la corteza cerebral temporal y occipital en los pacientes con EP y demencia y en los pacientes con EP no dementes con historia de AV. Esos hallazgos enfatizan la importancia de las estructuras corticales posteriores en la explicación de la presencia de deterioro cognitivo y alucinaciones visuales en la EP. Además fue observada una estrecha relación entre presencia de alucinaciones visuales y deterioro cognitivo progresivo. El deterioro cognitivo en los pacientes con alucinaciones visuales fue observado en funciones visuales complejas y de procesamiento semántico (interpretación perceptual de la información). Este patrón neuropsicológico estaría de acuerdo con nuestros hallazgos de resonancia magnética estructural en los cuales se evidenciaron cambios cerebrales de tipo atrófico en áreas visuales secundarias y áreas terciarias implicadas éstas últimas en la integración de la información semántica
Enhanced T-Cell Immunity to Osteosarcoma Through Antibody Blockade of PD-1/PD-L1 Interactions
No full textabstract: Osteosarcoma is the most common bone cancer in children and adolescents. Although 70% of patients with localized disease are cured with chemotherapy and surgical resection, patients with metastatic osteosarcoma are typically refractory to treatment. Numerous lines of evidence suggest that cytotoxic T lymphocytes (CTLs) limit the development of metastatic osteosarcoma. We have investigated the role of PD-1, an inhibitory TNFR family protein expressed on CTLs, in limiting the efficacy of immune-mediated control of metastatic osteosarcoma. We show that human metastatic, but not primary, osteosarcoma tumors express a ligand for PD-1 (PD-L1) and that tumor-infiltrating CTLs express PD-1, suggesting this pathway may limit CTLs control of metastatic osteosarcoma in patients. PD-L1 is also expressed on the K7M2 osteosarcoma tumor cell line that establishes metastases in mice, and PD-1 is expressed on tumor-infiltrating CTLs during disease progression. Blockade of PD-1/PD-L1 interactions dramatically improves the function of osteosarcoma-reactive CTLs in vitro and in vivo, and results in decreased tumor burden and increased survival in the K7M2 mouse model of metastatic osteosarcoma. Our results suggest that blockade of PD-1/PD-L1 interactions in patients with metastatic osteosarcoma should be pursued as a therapeutic strategy.This is a non-final version of an article published in final form as Lussier, Danielle M., O'Neill, Lauren, Nieves, Lizbeth M., McAfee, Megan S., Holechek, Susan A., Collins, Andrea W., Dickman, Paul, Jacobsen, Jeffrey, Hingorani, Pooja, & Blattman, Joseph N. (2015). Enhanced T-Cell Immunity to Osteosarcoma Through Antibody Blockade of PD-1/PD-L1 Interactions. JOURNAL OF IMMUNOTHERAPY, 38(3), 96-106. http://dx.doi.org/10.1097/CJI.000000000000006
Recommendation on the nomenclature for oral anticoagulants: Communication from the SSC of the ISTH: Reply
No full textPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111930/1/jth12969.pd
Pd-Catalyzed Cross-Coupling Reactions Promoted by Biaryl Phosphorinane Ligands
No full textWe report the use of biaryl phosphorinanes as ligands
for Pd-catalyzed
cross-coupling reactions. A modular synthesis was developed that employs
a double conjugate addition of primary biaryl phosphines into 1,1,5,5-tetraalkyl
penta-1,4-diene-3-ones. Notably, this synthesis does not require the
use of copper, a known contaminant in structurally related biaryl
phosphane ligands. Using the synthetic strategy described above, we
synthesized a library of biaryl phosphorinanes, varying their substitution
about phosphorus and the steric and electronic nature of the biaryl
motif. We then benchmarked their performance as ligands in Pd-catalyzed
cross coupling reactions such as aryl sulfonamidation, aryl alkoxylation,
and aryl amination in the presence of soluble organic bases. In each
reaction studied, many ligands outperformed biaryl phosphanes known
to promote the given transformation. Detailed substrate scopes were
determined using high-throughput screening technology. Several biaryl
phosphorinanes and their corresponding Pd(II) oxidative-addition complexes
were extensively characterized using NMR spectroscopy and X-ray crystallography.
General observations support that biaryl phosphorinanes promote reductive
elimination and form robust catalysts with palladium. In many cases
the use of these biaryl phosphorinanes may be advantageous over the
use of biaryl phosphanes with respect to lower catalyst loadings,
shorter reaction times, and robustness
Pd-Catalyzed Cross-Coupling Reactions Promoted by Biaryl Phosphorinane Ligands
No full textWe report the use of biaryl phosphorinanes as ligands
for Pd-catalyzed
cross-coupling reactions. A modular synthesis was developed that employs
a double conjugate addition of primary biaryl phosphines into 1,1,5,5-tetraalkyl
penta-1,4-diene-3-ones. Notably, this synthesis does not require the
use of copper, a known contaminant in structurally related biaryl
phosphane ligands. Using the synthetic strategy described above, we
synthesized a library of biaryl phosphorinanes, varying their substitution
about phosphorus and the steric and electronic nature of the biaryl
motif. We then benchmarked their performance as ligands in Pd-catalyzed
cross coupling reactions such as aryl sulfonamidation, aryl alkoxylation,
and aryl amination in the presence of soluble organic bases. In each
reaction studied, many ligands outperformed biaryl phosphanes known
to promote the given transformation. Detailed substrate scopes were
determined using high-throughput screening technology. Several biaryl
phosphorinanes and their corresponding Pd(II) oxidative-addition complexes
were extensively characterized using NMR spectroscopy and X-ray crystallography.
General observations support that biaryl phosphorinanes promote reductive
elimination and form robust catalysts with palladium. In many cases
the use of these biaryl phosphorinanes may be advantageous over the
use of biaryl phosphanes with respect to lower catalyst loadings,
shorter reaction times, and robustness
Pd-Catalyzed Cross-Coupling Reactions Promoted by Biaryl Phosphorinane Ligands
No full textWe report the use of biaryl phosphorinanes as ligands
for Pd-catalyzed
cross-coupling reactions. A modular synthesis was developed that employs
a double conjugate addition of primary biaryl phosphines into 1,1,5,5-tetraalkyl
penta-1,4-diene-3-ones. Notably, this synthesis does not require the
use of copper, a known contaminant in structurally related biaryl
phosphane ligands. Using the synthetic strategy described above, we
synthesized a library of biaryl phosphorinanes, varying their substitution
about phosphorus and the steric and electronic nature of the biaryl
motif. We then benchmarked their performance as ligands in Pd-catalyzed
cross coupling reactions such as aryl sulfonamidation, aryl alkoxylation,
and aryl amination in the presence of soluble organic bases. In each
reaction studied, many ligands outperformed biaryl phosphanes known
to promote the given transformation. Detailed substrate scopes were
determined using high-throughput screening technology. Several biaryl
phosphorinanes and their corresponding Pd(II) oxidative-addition complexes
were extensively characterized using NMR spectroscopy and X-ray crystallography.
General observations support that biaryl phosphorinanes promote reductive
elimination and form robust catalysts with palladium. In many cases
the use of these biaryl phosphorinanes may be advantageous over the
use of biaryl phosphanes with respect to lower catalyst loadings,
shorter reaction times, and robustness
Pd-Catalyzed Cross-Coupling Reactions Promoted by Biaryl Phosphorinane Ligands
No full textWe report the use of biaryl phosphorinanes as ligands
for Pd-catalyzed
cross-coupling reactions. A modular synthesis was developed that employs
a double conjugate addition of primary biaryl phosphines into 1,1,5,5-tetraalkyl
penta-1,4-diene-3-ones. Notably, this synthesis does not require the
use of copper, a known contaminant in structurally related biaryl
phosphane ligands. Using the synthetic strategy described above, we
synthesized a library of biaryl phosphorinanes, varying their substitution
about phosphorus and the steric and electronic nature of the biaryl
motif. We then benchmarked their performance as ligands in Pd-catalyzed
cross coupling reactions such as aryl sulfonamidation, aryl alkoxylation,
and aryl amination in the presence of soluble organic bases. In each
reaction studied, many ligands outperformed biaryl phosphanes known
to promote the given transformation. Detailed substrate scopes were
determined using high-throughput screening technology. Several biaryl
phosphorinanes and their corresponding Pd(II) oxidative-addition complexes
were extensively characterized using NMR spectroscopy and X-ray crystallography.
General observations support that biaryl phosphorinanes promote reductive
elimination and form robust catalysts with palladium. In many cases
the use of these biaryl phosphorinanes may be advantageous over the
use of biaryl phosphanes with respect to lower catalyst loadings,
shorter reaction times, and robustness
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