137 research outputs found
Excitonic and deep-level emission from N- and Al-polar homoepitaxial AlN grown by molecular beam epitaxy
Using low-temperature cathodoluminescence spectroscopy, we study the
properties of N- and Al-polar AlN layers grown by molecular beam epitaxy on
bulk AlN{0001}. Compared to the bulk AlN substrate, layers of both polarities
feature a suppression of deep-level luminescence, a total absence of the
prevalent donor with an exciton binding energy of 28 meV, and a much increased
intensity of the emission from free excitons. The dominant donor in these
layers is characterized by an associated exciton binding energy of 13 meV. The
observation of excited exciton states up to the exciton continuum allows us to
directly extract the free exciton binding energy of 57 meV
Determinants of whistleblowing intention : evidence from the South Korean government
In 2001, the South Korean government passed the Anti-Corruption Act, which provides whistleblower protection in the public sector. The system of protections and rewards was strengthened in 2011 by the Act on the Protection of Public Interest Whistleblowers. Although these laws ensure immunityâand even financial incentivesâfor whistleblowers, whistleblowing is still not a straightforward task. Based on a survey of 5706 public officials in central government, this study examines how a range of factors influence whistleblowing intention: attitude; knowledge; colleague support; organizational support; and protection against retaliation. A number of demographic variables, relating to gender; marital status; length of tenure; duty; and position type are used as controls. The results of the ordered probit regression analysis show all of the independent variables to have a significant positive effect on whistleblowing intention. However, colleague support and organizational support have the biggest effects, while perceived protection against retaliation has the smallest. This suggests that there is a need for future government efforts to build upon the available legal protections by focusing on creating a supportive culture among colleagues and in the organization more generally
3D Cascaded U-Net with a Squeeze-and-Exicitation Block for Semantic Segmentation on Kidney and Renal Cell Carcinoma in Abdonimal Volumetric CT
Segmentation is a fundamental process in medical image analysis. Recently, convolutional neural networks (CNNs) has allowed for automatic segmentation; however, segmentaiton of complex organs and diseases including the kidney or renal cell carcinoma (RCC) remains a different task due to limited data and labor-intensive labeling work. The purpose of this study is to segment kideny and RCC in CT using cascaded 3D U-Net with a squeeze-and-excitation (SE) block using a cascaded method. 210 kidneys and their RCC in abdominal CT images were used as training and validation sets. The Dice similarity coefficients (DSCs) of kidney and RCC in test set were 0.963 and 0.734 respectively. The cascaded semantic segmentation can potentially reduce segmentation efforts and increase the efficiency in clinical workflow
Association between composite dietary antioxidant index and handgrip strength in American adults: Data from National Health and Nutrition Examination Survey (NHANES, 2011-2014)
BackgroundThe Composite Dietary Antioxidant Index (CDAI), a composite score of multiple dietary antioxidants (including vitamin A, C, and E, selenium, zinc, and carotenoids), represents an individualâs comprehensive dietary antioxidant intake profile. CDAI was developed based on its combined effect on pro-inflammatory markers Tumor Necrosis Factor-α (TNF-α) and anti-inflammatory effects of Interleukin-1ÎČ (IL-1ÎČ), which are associated with many health outcomes, including depression, all-cause mortality, colorectal cancer, etc. Handgrip strength is used as a simple measure of muscle strength, not only is it highly correlated with overall muscle strength, but also serves as a diagnostic tool for many adverse health outcomes, including sarcopenia and frailty syndromes.PurposeThe association between CDAI and Handgrip strength (HGS) is currently unclear. This study investigated the association between CDAI (including its components) and HGS in 6,019 American adults.MethodThe research data were selected from the 2011â2014 National Health and Nutrition Survey (NHANES), and a total of 6,019 American adults were screened and included. A weighted generalized linear regression model was used to evaluate CDAI (including its components) and HGS.Results(1) CDAI was significantly positively correlated with HGS (ÎČ = 0.009, 0.005âŒ0.013, P < 0.001), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (ÎČ = 0.084, 0.042âŒ0.126, P = 0.002) and significant in trend test (P for trend < 0.0100). Gender subgroup analysis showed that male CDAI was significantly positively correlated with HGS (ÎČ = 0.015, 0.007âŒ0.023, P = 0.002), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (ÎČ = 0.131, 0.049âŒ0.213, P = 0.006) and the trend test was significant (P for trend < 0.0100). There was no correlation between female CDAI and HGS, and the trend test was not statistically significant (P > 0.05). (2) The intake of dietary vitamin E, Zinc and Selenium showed a significant positive correlation with HGS (ÎČ = 0.004, 0.002âŒ0.007, P = 0.006; ÎČ = 0.007, 0.004âŒ0.009, P < 0.001; ÎČ = 0.001, 0.001âŒ0.001, P < 0.001), vitamin A, vitamin C and carotenoid were significantly associated with HGS in the Crude Model, but this significant association disappeared in the complete model with the increase of control variables. Gender subgroup analysis showed that in model 3, male dietary intake levels of vitamin E, Zinc, and Selenium were significantly positively correlated with HGS (ÎČ = 0.005, 0.002âŒ0.009, P = 0.011; ÎČ = 0.007, 0.004âŒ0.011, P = 0.001; ÎČ = 0.001, 0.001âŒ0.001, P = 0.004), the rest of the indicators had no significant correlation with HGS. Among the female subjects, dietary zinc intake was significantly positively correlated with HGS (ÎČ = 0.005, 0.001âŒ0.008, P = 0.008), and there was no significant correlation between other indicators and HGS (P > 0.05).ConclusionThere was an association between the CDAI and HGS, but there was a gender difference, and there was an association between the CDAI and HGS in male, but the association was not significant in female. Intake of the dietary antioxidants vitamin E, selenium, and zinc was associated with HGS in male, but only zinc was associated with HGS among dietary antioxidants in female
Deregulation of DUX4 and ERG in acute lymphoblastic leukemia
Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL).1,2 Here, we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG are hallmarks of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases, and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt utilizes a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivating domains of ERG, but inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia, in which DUX4 deregulation results in loss-of-function of ERG, either by deletion or induction of expression of an isoform that is a dominant negative inhibitor of wild type ERG function
Determinants of Public Service Career Choice in Developing Countries
This study examines factors influencing public service career choice in developing countries through case studies and a survey. Based on the results of these case studies and survey, I conclude that job security, public service motivation, social recognition and status, and the opportunity for career development are important determinants in why individuals in developing countries choose a public service career. Bureaucratic power and family-related factors also play a role and reflect the high power distance and collectivist culture of developing countries
Motivation to Choose a Public Service Career in Developing Countries: Focused on Philippines, Bangladesh, Cambodia, Vietnam, and Indonesia
Transformational Leadership and its Impact on Employee Performance: Focus on Public Employees in Afghanistan
This study examines the relationship between transformational leadership and employee performance based on a survey conducted on 150 employees in low and middle level management positions in the Ministry of Public Works in Kabul, Afghanistan. The survey questionnaire consisted of questions about employee performance, transformational leadership (6 dimensions), pay satisfaction, job security, and demographic control variables. The result of OLS regression analysis concludes that two dimensions of transformational leadership â identifying and articulating a vision, and intellectual stimulation â are statistically significant and positively related to employee performance. In addition, job security is highly significant and related to employee performance.</p
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