Showing papers by "The Chinese University of Hong Kong published in 2011"
TL;DR: A simple but effective image prior - dark channel prior to remove haze from a single input image is proposed, based on a key observation - most local patches in haze-free outdoor images contain some pixels which have very low intensities in at least one color channel.
Abstract: In this paper, we propose a simple but effective image prior-dark channel prior to remove haze from a single input image. The dark channel prior is a kind of statistics of outdoor haze-free images. It is based on a key observation-most local patches in outdoor haze-free images contain some pixels whose intensity is very low in at least one color channel. Using this prior with the haze imaging model, we can directly estimate the thickness of the haze and recover a high-quality haze-free image. Results on a variety of hazy images demonstrate the power of the proposed prior. Moreover, a high-quality depth map can also be obtained as a byproduct of haze removal.
3,668 citations
TL;DR: A set of novel features, including multiscale contrast, center-surround histogram, and color spatial distribution, are proposed to describe a salient object locally, regionally, and globally.
Abstract: In this paper, we study the salient object detection problem for images. We formulate this problem as a binary labeling task where we separate the salient object from the background. We propose a set of novel features, including multiscale contrast, center-surround histogram, and color spatial distribution, to describe a salient object locally, regionally, and globally. A conditional random field is learned to effectively combine these features for salient object detection. Further, we extend the proposed approach to detect a salient object from sequential images by introducing the dynamic salient features. We collected a large image database containing tens of thousands of carefully labeled images by multiple users and a video segment database, and conducted a set of experiments over them to demonstrate the effectiveness of the proposed approach.
2,319 citations
TL;DR: In this article, the authors examine a potential benefit associated with the initiation of voluntary disclosure of corporate social responsibility (CSR) activities: a reduction in firms' cost of equity capital.
Abstract: We examine a potential benefit associated with the initiation of voluntary disclosure of corporate social responsibility (CSR) activities: a reduction in firms’ cost of equity capital. We find that firms with a high cost of equity capital in the previous year tend to initiate disclosure of CSR activities in the current year and that initiating firms with superior social responsibility performance enjoy a subsequent reduction in the cost of equity capital. Further, initiating firms with superior social responsibility performance attract dedicated institutional investors and analyst coverage. Moreover, these analysts achieve lower absolute forecast errors and dispersion. Finally, we find that firms exploit the benefit of a lower cost of equity capital associated with the initiation of CSR disclosure. Initiating firms are more likely than non-initiating firms to raise equity capital following the initiations; among firms raising equity capital, initiating firms raise a significantly larger amount t...
1,984 citations
University of Maryland, College Park1, Queen's University2, Cornell University3, University of Minnesota4, Nanyang Technological University5, McKinsey & Company6, Koç University7, Jacobs University Bremen8, University of Minho9, The Chinese University of Hong Kong10, Indian Institute of Management Ahmedabad11, Pontifical Catholic University of Peru12, University of Valencia13, Johannes Kepler University of Linz14, Victoria University of Wellington15, Hungarian Academy of Sciences16, National and Kapodistrian University of Athens17, La Trobe University18, University of Melbourne19, Sungkyunkwan University20, ESSEC Business School21, University of San Diego22, Katholieke Universiteit Leuven23, University of Patras24, Human Sciences Research Council25, ODESSA26, University of Tartu27, Norwegian School of Economics28, University of Koblenz and Landau29, University of Sussex30, University of Sindh31, Gakushuin University32, University of Groningen33, University of Tokyo34
TL;DR: The differences across cultures in the enforcement of conformity may reflect their specific histories and advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.
Abstract: With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.
1,895 citations
09 Feb 2011
TL;DR: This paper proposes a matrix factorization framework with social regularization, which can be easily extended to incorporate other contextual information, like social tags, etc, and demonstrates that the approaches outperform other state-of-the-art methods.
Abstract: Although Recommender Systems have been comprehensively analyzed in the past decade, the study of social-based recommender systems just started. In this paper, aiming at providing a general method for improving recommender systems by incorporating social network information, we propose a matrix factorization framework with social regularization. The contributions of this paper are four-fold: (1) We elaborate how social network information can benefit recommender systems; (2) We interpret the differences between social-based recommender systems and trust-aware recommender systems; (3) We coin the term Social Regularization to represent the social constraints on recommender systems, and we systematically illustrate how to design a matrix factorization objective function with social regularization; and (4) The proposed method is quite general, which can be easily extended to incorporate other contextual information, like social tags, etc. The empirical analysis on two large datasets demonstrates that our approaches outperform other state-of-the-art methods.
1,573 citations
TL;DR: In this article, the authors examined the relationship between disclosure of nonfinancial information and analyst forecast accuracy using firm-level data from 31 countries and found that the issuance of standalone corporate social responsibility (CSR) reports is associated with lower analyst forecast error.
Abstract: We examine the relationship between disclosure of nonfinancial information and analyst forecast accuracy using firm-level data from 31 countries. We use the issuance of standalone corporate social responsibility (CSR) reports to proxy for disclosure of nonfinancial information. We find that the issuance of standalone CSR reports is associated with lower analyst forecast error. This relationship is stronger in countries that are more stakeholder-oriented — i.e., in countries where CSR performance is more likely to affect firm financial performance. The relationship is also stronger for firms and countries with more opaque financial disclosure, suggesting that issuance of standalone CSR reports plays a role complementary to financial disclosure. These results hold after we control for various factors related to firm financial transparency and other potentially confounding institutional factors. Collectively, our findings have important implications for academics and practitioners in understanding the function of CSR disclosure in financial markets.
1,028 citations
12 Dec 2011
TL;DR: This work presents a new image editing method, particularly effective for sharpening major edges by increasing the steepness of transition while eliminating a manageable degree of low-amplitude structures in an optimization framework making use of L0 gradient minimization.
Abstract: We present a new image editing method, particularly effective for sharpening major edges by increasing the steepness of transition while eliminating a manageable degree of low-amplitude structures. The seemingly contradictive effect is achieved in an optimization framework making use of L0 gradient minimization, which can globally control how many non-zero gradients are resulted in to approximate prominent structure in a sparsity-control manner. Unlike other edge-preserving smoothing approaches, our method does not depend on local features, but instead globally locates important edges. It, as a fundamental tool, finds many applications and is particularly beneficial to edge extraction, clip-art JPEG artifact removal, and non-photorealistic effect generation.
919 citations
TL;DR: A review examines how this diagnosis should be established and how to recognize pseudoresistance and explains possible mechanisms of drug-resistant epilepsy and presents treatment strategies.
Abstract: Nearly a quarter of patients with seizures have drug-resistant epilepsy. This review examines how this diagnosis should be established and how to recognize pseudoresistance. It explains possible mechanisms of drug-resistant epilepsy and presents treatment strategies.
874 citations
TL;DR: The basic strategies for crystal facet engineering of photocatalysts are presented and the recent advances in synthesizing faceted photo-reduction and oxidation sites, in particular TiO(2) crystals are described.
854 citations
Dresden University of Technology1, Royal Perth Hospital2, Trinity College, Dublin3, University of the West Indies4, Mater Dei Hospital5, The Chinese University of Hong Kong6, Friedrich Loeffler Institute7, Health Protection Agency8, University of Lyon9, Curtin University10, Shaikh Khalifa Medical City11
TL;DR: A high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements is shown, and the data indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements.
Abstract: In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements.
834 citations
TL;DR: Multiplexed maternal plasma DNA sequencing analysis could be used to rule out fetal trisomy 21 among high risk pregnancies and if referrals for amniocentesis or chorionic villus sampling were based on the sequencing test results, about 98% of the invasive diagnostic procedures could be avoided.
Abstract: Objectives To validate the clinical efficacy and practical feasibility of massively parallel maternal plasma DNA sequencing to screen for fetal trisomy 21 among high risk pregnancies clinically indicated for amniocentesis or chorionic villus sampling. Design Diagnostic accuracy validated against full karyotyping, using prospectively collected or archived maternal plasma samples. Setting Prenatal diagnostic units in Hong Kong, United Kingdom, and the Netherlands. Participants 753 pregnant women at high risk for fetal trisomy 21 who underwent definitive diagnosis by full karyotyping, of whom 86 had a fetus with trisomy 21. Intervention Multiplexed massively parallel sequencing of DNA molecules in maternal plasma according to two protocols with different levels of sample throughput: 2-plex and 8-plex sequencing. Main outcome measures Proportion of DNA molecules that originated from chromosome 21. A trisomy 21 fetus was diagnosed when the z score for the proportion of chromosome 21 DNA molecules was >3. Diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were calculated for trisomy 21 detection. Results Results were available from 753 pregnancies with the 8-plex sequencing protocol and from 314 pregnancies with the 2-plex protocol. The performance of the 2-plex protocol was superior to that of the 8-plex protocol. With the 2-plex protocol, trisomy 21 fetuses were detected at 100% sensitivity and 97.9% specificity, which resulted in a positive predictive value of 96.6% and negative predictive value of 100%. The 8-plex protocol detected 79.1% of the trisomy 21 fetuses and 98.9% specificity, giving a positive predictive value of 91.9% and negative predictive value of 96.9%. Conclusion Multiplexed maternal plasma DNA sequencing analysis could be used to rule out fetal trisomy 21 among high risk pregnancies. If referrals for amniocentesis or chorionic villus sampling were based on the sequencing test results, about 98% of the invasive diagnostic procedures could be avoided.
TL;DR: This paper proposes a collaborative filtering approach for predicting QoS values of Web services and making Web service recommendation by taking advantages of past usage experiences of service users, and shows that the algorithm achieves better prediction accuracy than other approaches.
Abstract: With increasing presence and adoption of Web services on the World Wide Web, Quality-of-Service (QoS) is becoming important for describing nonfunctional characteristics of Web services. In this paper, we present a collaborative filtering approach for predicting QoS values of Web services and making Web service recommendation by taking advantages of past usage experiences of service users. We first propose a user-collaborative mechanism for past Web service QoS information collection from different service users. Then, based on the collected QoS data, a collaborative filtering approach is designed to predict Web service QoS values. Finally, a prototype called WSRec is implemented by Java language and deployed to the Internet for conducting real-world experiments. To study the QoS value prediction accuracy of our approach, 1.5 millions Web service invocation results are collected from 150 service users in 24 countries on 100 real-world Web services in 22 countries. The experimental results show that our algorithm achieves better prediction accuracy than other approaches. Our Web service QoS data set is publicly released for future research.
TL;DR: Whether implementing additional “train-low” strategies to increase the training adaptation leads to enhanced performance in well-trained individuals is unclear.
Abstract: An athlete’s carbohydrate intake can be judged by whether total daily intake and the timing of consumption in relation to exercise maintain adequate carbohydrate substrate for the muscle and central nervous system (‘‘high carbohydrate availability’’) or whether carbohydrate fuel sources are limiting for the daily exercise programme (‘‘low carbohydrate availability’’). Carbohydrate availability is increased by consuming carbohydrate in the hours or days prior to the session, intake during exercise, and refuelling during recovery between sessions. This is important for the competition setting or for high-intensity training where optimal performance is desired. Carbohydrate intake during exercise should be scaled according to the characteristics of the event. During sustained high-intensity sports lasting *1 h, small amounts of carbohydrate, including even mouth-rinsing, enhance performance via central nervous system effects. While 30–60 g h 71 is an appropriate target for sports of longer duration, events42.5 h may benefit from higher intakes of up to 90 g h 71 . Products containing special blends of different carbohydrates may maximize absorption of carbohydrate at such high rates. In real life, athletes undertake training sessions with varying carbohydrate availability. Whether implementing additional ‘‘train-low’’ strategies to increase the training adaptation leads to enhanced performance in well-trained individuals is unclear.
TL;DR: In this article, a model that specifies the relationship between internal integration, relationship commitment, and external integration, using data collected from manufacturing firms in China, is proposed and tested, and the results indicate that for Chinese controlled companies where there is a strong collectivism culture and more reliance on "Guanxi" (relationship), relationship commitment has a significant impact on external integration with suppliers and customers.
TL;DR: The goal of this paper is to review the state-of-the-art progress on visual tracking methods, classify them into different categories, as well as identify future trends.
Indiana University – Purdue University Indianapolis1, University of Pittsburgh2, Harvard University3, University of California, San Francisco4, University of Münster5, Peter MacCallum Cancer Centre6, Royal Brisbane and Women's Hospital7, University of Nottingham8, University of Porto9, Singapore General Hospital10, The Chinese University of Hong Kong11, Cancer Research UK12, The Breast Cancer Research Foundation13
TL;DR: The purpose of this article was to discuss the relationship between basal-like and triple-negative breast cancers, and to clarify practical implications of these diagnoses for pathologists and oncologists.
TL;DR: The authors examined the benefits and costs associated with foreign independent directors (FIDs) at U.S. corporations and found that firms with FIDs make better cross-border acquisitions when the targets are from the home regions of FIDs.
Abstract: We examine the benefits and costs associated with foreign independent directors (FIDs) at U.S. corporations. We find that firms with FIDs make better cross-border acquisitions when the targets are from the home regions of FIDs. However, FIDs also display poor board meeting attendance records, and firms with FIDs are more prone to commit intentional financial misreporting and overpay their CEOs and have lower CEO turnover sensitivity to performance. Finally, firms with FIDs are associated with significantly poorer performance, especially as their business presence in the FID’s home region becomes less important.
TL;DR: The results indicated that the formation rate of (·)OH on the surface of irradiated commercial Degussa P25 (P25) was much higher than that of other semiconductor.
TL;DR: This article proposes new filtering techniques by exploiting the token ordering information and drastically reduce the candidate sizes and hence improve the efficiency of existing algorithms to find a pair of records such that their similarities are no less than a given threshold.
Abstract: With the increasing amount of data and the need to integrate data from multiple data sources, one of the challenging issues is to identify near-duplicate records efficiently. In this article, we focus on efficient algorithms to find a pair of records such that their similarities are no less than a given threshold. Several existing algorithms rely on the prefix filtering principle to avoid computing similarity values for all possible pairs of records. We propose new filtering techniques by exploiting the token ordering information; they are integrated into the existing methods and drastically reduce the candidate sizes and hence improve the efficiency. We have also studied the implementation of our proposed algorithm in stand-alone and RDBMS-based settings. Experimental results show our proposed algorithms can outperform previous algorithms on several real datasets.
TL;DR: In this paper, the role of financial reporting quality (FRQ) in investment efficiency in private firms from emerging markets was examined and the relationship between FRQ and investment efficiency was found to increase in bank financing and decrease in incentives to minimize earnings for tax purposes.
Abstract: Prior research shows that financial reporting quality (FRQ) is positively related to investment efficiency for large U.S. publicly traded companies. We examine the role of FRQ in private firms from emerging markets, a setting in which extant research suggests that FRQ would be less conducive to the mitigation of investment inefficiencies. Earlier studies show that private firms have lower FRQ, presumably because of lower market demand for public information. Prior research also shows that FRQ is lower in countries with low investor protection, bank-oriented financial systems, and stronger conformity between tax and financial reporting rules. Using firm-level data from the World Bank, our empirical evidence suggests that FRQ positively affects investment efficiency. We further find that the relation between FRQ and investment efficiency is increasing in bank financing and decreasing in incentives to minimize earnings for tax purposes. Such a connection between tax-minimization incentives and the...
TL;DR: A simple-to-use risk score that uses baseline clinical variables was developed and validated and accurately estimates the risk of developing HCC at 3, 5, and 10 years in patients with chronic hepatitis B.
Abstract: Summary Background Therapy for chronic hepatitis B reduces the risk of progressing to hepatocellular carcinoma (HCC); however, there is no suitable and accurate means to assess risk. This study aimed to develop and validate a simple scoring system to predict HCC risk in patients with chronic hepatitis B. Methods The development cohort consisted of 3584 patients without cirrhosis from the community-based Taiwanese REVEAL-HBV study (of whom 131 developed HCC during follow-up), and a validation cohort of 1505 patients from three hospitals in Hong Kong and South Korea (of whom 111 developed HCC during follow-up). We used Cox multivariate proportional hazards model to predict risk of HCC at 3, 5, and 10 years. Variables included in the risk score were sex, age, serum alanine aminotransferase concentration, HBeAg status, and serum HBV DNA level. We calculated the area under receiver operating curve (AUROC) and calibration of predicted and observed HCC risk. Findings A 17-point risk score was developed, with HCC risk ranging from 0·0% to 23·6% at 3 years, 0·0% to 47·4% at 5 years, and 0·0% to 81·6% at 10 years for patients with the lowest and highest HCC risk, respectively. AUROCs to predict risk were 0·811 (95% CI 0·790–0·831) at 3 years, 0·796 (0·775–0·816) at 5 years, and 0·769 (0·747–0·790) at 10 years in the validation cohort, and 0·902 (0·884–0·918), 0·783 (0·759–0·806), and 0·806 (0·783–0·828), respectively, after exclusion of 277 patients in the validation cohort with cirrhosis. Predicted risk was well calibrated with Kaplan-Meier observed HCC risk. Interpretation A simple-to-use risk score that uses baseline clinical variables was developed and validated. The score accurately estimates the risk of developing HCC at 3, 5, and 10 years in patients with chronic hepatitis B. Clinicians can use this score to assess risk of HCC in patients with chronic hepatitis B and subsequently make evidence-based decisions about their clinical management. Funding The Academia Sinica; the National Health Research Institute, Taiwan; and Bristol-Myers Squibb.
TL;DR: Targeting the downstream TGF-β/Smad3 signaling pathway by gene transfer of either Smad7 or Smad3-dependent microRNAs may represent a specific and effective therapeutic strategy for kidney disease.
Abstract: TGF-β1 has been long considered as a key mediator in renal fibrosis and induces renal scarring largely by activating its downstream Smad signaling pathway. Interestingly, while mice overexpressing active TGF-β1 develop progressive renal injury, latent TGF-β1 plays a protective role in renal fibrosis and inflammation. Under disease conditions, Smad2 and Smad3 are highly activated, while Smad7 is degraded through the ubiquitin proteasome degradation mechanism. In addition to TGF-β1, many pathogenic mediators such as angiotensin II and advanced glycation end products can also activate the Smad pathway via both TGF-β-dependent and independent mechanisms. Smads interact with other signaling pathways, such as the MAPK and NF-κB pathways, to positively or negatively regulate renal inflammation and fibrosis. Studies from gene knockout mice demonstrate that TGF-β1 acts by stimulating its downstream Smads to diversely regulate kidney injury. In the context of renal fibrosis and inflammation, Smad3 is pathogenic, while Smad2 and Smad7 are protective. Smad4 exerts its diverse roles by transcriptionally enhancing Smad3-mediated renal fibrosis while inhibiting NF-κB-driven renal inflammation via a Smad7-dependent mechanism. Furthermore, we also demonstrated that TGF-β1 acts by stimulating Smad3 to positively or negatively regulate microRNAs to exert its fibrotic role in kidney disease. In conclusion, TGF-β/Smad signaling is a major pathway leading to kidney disease. Smad3 is a key mediator in renal fibrosis and inflammation, whereas Smad2 and Smad7 are renoprotective. Smad4 exerts its diverse role in promoting renal fibrosis while inhibiting inflammation. Thus, targeting the downstream TGF-β/Smad3 signaling pathway by gene transfer of either Smad7 or Smad3-dependent microRNAs may represent a specific and effective therapeutic strategy for kidney disease.
TL;DR: Patients with reversible cerebral vasoconstriction syndromes have a unique set of clinical imaging features, with no significant differences between subgroups, and the effects of empirical treatment with calcium channel blockers and glucocorticoids are investigated.
Abstract: Objectives To compare the clinical, laboratory, and imaging features of patients with reversible cerebral vasoconstriction syndromes evaluated at 2 academic centers, compare subgroups, and investigate treatment effects. Design Retrospective analysis. Setting Massachusetts General Hospital (n = 84) or Cleveland Clinic (n = 55). Patients One hundred thirty-nine patients with reversible cerebral vasoconstriction syndromes. Main Outcome Measures Clinical, laboratory, and imaging features; treatment; and outcomes. Results The mean age was 42.5 years, and 81% were women. Onset with thunderclap headache was documented in 85% and 43% developed neurological deficits. Prior migraine was documented in 40%, vasoconstrictive drug exposure in 42%, and recent pregnancy in 9%. Admission computed tomography or magnetic resonance imaging was normal in 55%; however, 81% ultimately developed brain lesions including infarcts (39%), convexity subarachnoid hemorrhage (34%), lobar hemorrhage (20%), and brain edema (38%). Cerebral angiographic abnormalities typically normalized within 2 months. Nearly 90% had good clinical outcome; 9% developed severe deficits; and 2% died. In the combined cohort, calcium channel blocker therapy and symptomatic therapy alone showed no significant effect on outcome; however, glucocorticoid therapy showed a trend for poor outcome (P = .08). Subgroup comparisons based on prior headache status and identified triggers (vasoconstrictive drugs, pregnancy, other) showed no major differences. Conclusion Patients with reversible cerebral vasoconstriction syndromes have a unique set of clinical imaging features, with no significant differences between subgroups. Prospective studies are warranted to determine the effects of empirical treatment with calcium channel blockers and glucocorticoids.
TL;DR: In this paper, using a microRNA microarray and real-time PCR, wild-type mice had reduced expression of miR-29 along with the development of progressive renal fibrosis in obstructive nephropathy.
Abstract: TGF-β/Smad3 signaling promotes fibrosis, but the development of therapeutic interventions involving this pathway will require the identification and ultimate targeting of downstream fibrosis-specific genes In this study, using a microRNA microarray and real-time PCR, wild-type mice had reduced expression of miR-29 along with the development of progressive renal fibrosis in obstructive nephropathy In contrast, Smad3 knockout mice had increased expression of miR-29 along with the absence of renal fibrosis in the same model of obstruction In cultured fibroblasts and tubular epithelial cells, Smad3 mediated TGF-β(1)-induced downregulation of miR-29 by binding to the promoter of miR-29 Furthermore, miR-29 acted as a downstream inhibitor and therapeutic microRNA for TGF-β/Smad3-mediated fibrosis In vitro, overexpression of miR-29b inhibited, but knockdown of miR-29 enhanced, TGF-β(1)-induced expression of collagens I and III by renal tubular cells Ultrasound-mediated gene delivery of miR-29b either before or after established obstructive nephropathy blocked progressive renal fibrosis In conclusion, miR-29 is a downstream inhibitor of TGF-β/Smad3-mediated fibrosis and may have therapeutic potential for diseases involving fibrosis
TL;DR: The use of graphene to enhance the efficiency of photocatalysts has attracted much attention because of the unique optical and electrical properties of the two-dimensional (2D) material.
Abstract: The use of graphene to enhance the efficiency of photocatalysts has attracted much attention. This is because of the unique optical and electrical properties of the two-dimensional (2-D) material. This review is focused on the recent significant advances in the fabrication and applications of graphene-based hybrid photocatalysts. The synthetic strategies for the composite semiconductor photocatalysts are described. The applications of the new materials in the degradation of pollutants, photocatalytic hydrogen evolution and antibacterial systems are presented. The challenges and opportunities for the future development of graphene-based photocatalysts are also discussed.
George Washington University1, University of Pennsylvania2, University of California, San Francisco3, Alfaisal University4, Harvard University5, Leipzig University6, Olean General Hospital7, University of Helsinki8, University of Sheffield9, Karolinska Institutet10, The Chinese University of Hong Kong11, Tufts University12, Australian National University13, University of Toronto14
TL;DR: In this article, the authors describe emergency care systems and the extent of crowding across 15 countries outside of the United States: Australia, Canada, Denmark, Finland, France, Germany, Hong Kong, India, Iran, Italy, The Netherlands, Saudi Arabia, Catalonia (Spain), Sweden, and the United Kingdom.
Abstract: The maturation of emergency medicine (EM) as a specialty has coincided with dramatic increases in emergency department (ED) visit rates, both in the United States and around the world ED crowding has become a public health problem where periodic supply and demand mismatches in ED and hospital resources cause long waiting times and delays in critical treatments ED crowding has been associated with several negative clinical outcomes, including higher complication rates and mortality This article describes emergency care systems and the extent of crowding across 15 countries outside of the United States: Australia, Canada, Denmark, Finland, France, Germany, Hong Kong, India, Iran, Italy, The Netherlands, Saudi Arabia, Catalonia (Spain), Sweden, and the United Kingdom The authors are local emergency care leaders with knowledge of emergency care in their particular countries Where available, data are provided about visit patterns in each country; however, for many of these countries, no national data are available on ED visits rates or crowding For most of the countries included, there is both objective evidence of increases in ED visit rates and ED crowding and also subjective assessments of trends toward higher crowding in the ED ED crowding appears to be worsening in many countries despite the presence of universal health coverage Scandinavian countries with robust systems to manage acute care outside the ED do not report crowding is a major problem The main cause for crowding identified by many authors is the boarding of admitted patients, similar to the United States Many hospitals in these countries have implemented operational interventions to mitigate crowding in the ED, and some countries have imposed strict limits on ED length of stay (LOS), while others have no clear plan to mitigate crowding An understanding of the causes and potential solutions implemented in these countries can provide a lens into how to mitigate ED crowding in the United States through health policy interventions and hospital operational changes
TL;DR: The results indicate that the effect of urban heat island in Hong Kong is mainly located in three sub-urban areas, namely, Kowloon Island, the northern Hong Kong Island and Hong Kong International Airport.
Abstract: In this paper, the effect of urban heat island is analyzed using the Landsat TM data and ASTER data in 2005 as a case study in Hong Kong. Two algorithms were applied to retrieve the land surface temperature (LST) distribution from the Landsat TM and ASTER data. The spatial pattern of LST in the study area is retrieved to characterize their local effects on urban heat island. In addition, the correlation between LST and the normalized difference vegetation index (NDVI), the normalized difference build-up index (NDBI) is analyzed to explore the impacts of the green land and the build-up land on the urban heat island by calculating the ecological evaluation index of sub-urban areas. The results indicate that the effect of urban heat island in Hong Kong is mainly located in three sub-urban areas, namely, Kowloon Island, the northern Hong Kong Island and Hong Kong International Airport. The correlation between LST and NDVI, NDBI also indicates that the negative correlation of LST and NDVI suggests that the green land can weaken the effect on urban heat island, while the positive correlation between LST and NDBI means that the built-up land can strengthen the effect of urban heat island in our case study. Although satellite data (e.g., Landsat TM and ASTER thermal bands data) can be applied to examine the distribution of urban heat islands in places such as Hong Kong, the method still needs to be refined with in situ measurements of LST in future studies.
TL;DR: Eltrombopag is effective for management of chronic immune thrombocytopenia, and could be particularly beneficial for patients who have not responded to splenectomy or previous treatment, and should be balanced with the potential risks associated with eltrom bopag treatment.
TL;DR: It is demonstrated that miR-21 induces tumor angiogenesis through targeting PTEN, leading to activate AKT and ERK1/2 signaling pathways, and thereby enhancing Hif-1α and VEGF expression; HIF-1 α is a key downstream target of miR -21 in regulating tumorAngiogenesis.
Abstract: MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated kinases (ERK) 1/2 are activated by miR-21. Inhibition of miR-21 by the antigomir blocked this process. Overexpression of the miR-21 target, PTEN, also inhibited tumor angiogenesis by partially inactivating AKT and ERK and decreasing the expression of HIF-1 and VEGF. The AKT and ERK inhibitors, LY294002 and U0126, suppressed HIF-1α and VEGF expression and angiogenesis. Moreover, inhibition of HIF-1α expression alone abolished miR-21-inducing tumor angiogenesis, indicating that HIF-1α is required for miR-21-upregulated angiogenesis. Therefore, we demonstrate that miR-21 induces tumor angiogenesis through targeting PTEN, leading to activate AKT and ERK1/2 signaling pathways, and thereby enhancing HIF-1α and VEGF expression; HIF-1α is a key downstream target of miR-21 in regulating tumor angiogenesis.
TL;DR: The denoising process is expressed as a linear expansion of thresholds (LET) that is optimized by relying on a purely data-adaptive unbiased estimate of the mean-squared error (MSE) derived in a non-Bayesian framework (PURE: Poisson-Gaussian unbiased risk estimate).
Abstract: We propose a general methodology (PURE-LET) to design and optimize a wide class of transform-domain thresholding algorithms for denoising images corrupted by mixed Poisson-Gaussian noise. We express the denoising process as a linear expansion of thresholds (LET) that we optimize by relying on a purely data-adaptive unbiased estimate of the mean-squared error (MSE), derived in a non-Bayesian framework (PURE: Poisson-Gaussian unbiased risk estimate). We provide a practical approximation of this theoretical MSE estimate for the tractable optimization of arbitrary transform-domain thresholding. We then propose a pointwise estimator for undecimated filterbank transforms, which consists of subband-adaptive thresholding functions with signal-dependent thresholds that are globally optimized in the image domain. We finally demonstrate the potential of the proposed approach through extensive comparisons with state-of-the-art techniques that are specifically tailored to the estimation of Poisson intensities. We also present denoising results obtained on real images of low-count fluorescence microscopy.