•The COVID-19 pandemic has significant impacts on global financial markets.•Substantial increases of volatility are found in global markets due to the outbreak.•Global stock markets linkages display ...clear different patterns before and after the pandemic announcement.•Policy responses may create further uncertainties in the global financial markets.
The rapid spread of coronavirus (COVID-19) has dramatic impacts on financial markets all over the world. It has created an unprecedented level of risk, causing investors to suffer significant loses in a very short period of time. This paper aims to map the general patterns of country-specific risks and systemic risks in the global financial markets. It also analyses the potential consequence of policy interventions, such as the US’ decision to implement a zero-percent interest rate and unlimited quantitative easing (QE), and to what extent these policies may introduce further uncertainties into global financial markets.
Estrogen dysregulation causes hair disorder. Clinical observations have demonstrated that estrogen raises the telogen/anagen ratio and inhibits hair shaft elongation of female scalp hair follicles. ...In spite of these clinical insights, the properties of estrogen on hair follicles are poorly dissected. In the present study, we show that estrogen induced apoptosis of precortex cells and caused premature catagen by up-regulation of TGF β2. Immediately after the premature catagen, the expression of anagen chalone BMP4 increased. The up-regulation of BMP4 may further function to prevent anagen transition and maintain telogen. Interestingly, the hair follicle stem cell niche was not destructed during these drastic structural changes caused by estrogen. Additionally, dermal papilla cells, the estrogen target cells in hair follicles, kept their signature gene expressions as well as their hair inductive potential after estrogen treatment. Retention of the characteristics of both hair follicle stem cells and dermal papilla cells determined the reversibility of the hair cycle suppression. These results indicated that estrogen causes reversible hair cycle retardation by inducing premature catagen and maintaining telogen.
The irregular domain and lack of ordering make it challenging to design deep neural networks for point cloud processing. This paper presents a novel framework named
Point Cloud Transformer
(PCT) for ...point cloud learning. PCT is based on Transformer, which achieves huge success in natural language processing and displays great potential in image processing. It is inherently permutation invariant for processing a sequence of points, making it well-suited for point cloud learning. To better capture local context within the point cloud, we enhance input embedding with the support of farthest point sampling and nearest neighbor search. Extensive experiments demonstrate that the PCT achieves the state-of-the-art performance on shape classification, part segmentation, semantic segmentation, and normal estimation tasks.
Fecal calprotectin (FC) is a relatively new marker of intestinal inflammation. Recently, many studies have extended its role in predicting relapse of quiescent inflammatory bowel disease (IBD), but ...the reported results have been inconsistent. We aimed to perform a meta-analysis of the predictive capacity of FC in IBD relapse.
We systematically searched the Medline, Web of Science, Cochrane Library, and EMBASE databases for prospective studies that used FC concentrations at remission in predicting relapse of Crohn's disease (CD) and ulcerative colitis (UC). Pooled sensitivity, specificity, and other diagnostic indices were evaluated.
A total of 672 IBD patients (318 UC and 354 CD) from six different studies were analyzed. The pooled sensitivity and specificity of FC to predict relapse of quiescent IBD was 78% (95% confidence interval CI: 72-83) and 73% (95% CI: 68-77), respectively. The area under the summary receiver-operating characteristic (sROC) curve was 0.83 and the diagnostic odds ratio was 10.31 (95% CI: 5.05-21.06). The capacity of FC to predict relapse was comparable between UC and CD. In CD patients the predictive value of FC in isolated small bowel CD was not assessed due to insufficiency of available data. Compared with all enrolled CD patients, FC appeared to be more accurate in ileocolonic and colonic CD.
As a simple and noninvasive marker, FC is useful to predict relapse in quiescent IBD patients.
Humans can naturally and effectively find salient regions in complex scenes. Motivated by this observation, attention mechanisms were introduced into computer vision with the aim of imitating this ...aspect of the human visual system. Such an attention mechanism can be regarded as a dynamic weight adjustment process based on features of the input image. Attention mechanisms have achieved great success in many visual tasks, including image classification, object detection, semantic segmentation, video understanding, image generation, 3D vision, multimodal tasks, and self-supervised learning. In this survey, we provide a comprehensive review of various attention mechanisms in computer vision and categorize them according to approach, such as channel attention, spatial attention, temporal attention, and branch attention; a related repository
https://github.com/MenghaoGuo/Awesome-Vision-Attentions
is dedicated to collecting related work. We also suggest future directions for attention mechanism research.
Attention mechanisms, especially self-attention, have played an increasingly important role in deep feature representation for visual tasks. Self-attention updates the feature at each position by ...computing a weighted sum of features using pair-wise affinities across all positions to capture the long-range dependency within a single sample. However, self-attention has quadratic complexity and ignores potential correlation between different samples. This article proposes a novel attention mechanism which we call external attention , based on two external, small, learnable, shared memories, which can be implemented easily by simply using two cascaded linear layers and two normalization layers; it conveniently replaces self-attention in existing popular architectures. External attention has linear complexity and implicitly considers the correlations between all data samples. We further incorporate the multi-head mechanism into external attention to provide an all-MLP architecture, external attention MLP (EAMLP), for image classification. Extensive experiments on image classification, object detection, semantic segmentation, instance segmentation, image generation, and point cloud analysis reveal that our method provides results comparable or superior to the self-attention mechanism and some of its variants, with much lower computational and memory costs.
The prevalence and prognosis of digestive system involvement, including gastrointestinal symptoms and liver injury, in patients with COVID-19 remains largely unknown. We aimed to quantify the effects ...of COVID-19 on the digestive system.
In this systematic review and meta-analysis, we systematically searched PubMed, Embase, and Web of Science for studies published between Jan 1, 2020, and April 4, 2020. The websites of WHO, CDC, and major journals were also searched. We included studies that reported the epidemiological and clinical features of COVID-19 and the prevalence of gastrointestinal findings in infected patients, and excluded preprints, duplicate publications, reviews, editorials, single case reports, studies pertaining to other coronavirus-related illnesses, and small case series (<10 cases). Extracted data included author; date; study design; country; patient demographics; number of participants in severe and non-severe disease groups; prevalence of clinical gastrointestinal symptoms such as vomiting, nausea, diarrhoea, loss of appetite, abdominal pain, and belching; and digestive system comorbidities including liver disease and gastrointestinal diseases. Raw data from studies were pooled to determine effect estimates.
We analysed findings from 35 studies, including 6686 patients with COVID-19, that met inclusion criteria. 29 studies (n=6064) reported gastrointestinal symptoms in patients with COVID-19 at diagnosis, and the pooled prevalence of digestive system comorbidities was 4% (95% CI 2-5; range 0-15; I
=74%). The pooled prevalence of digestive symptoms was 15% (10-21; range: 2-57; I
=96%) with nausea or vomiting, diarrhoea, and loss of appetite being the three most common symptoms. The pooled prevalence of abnormal liver functions (12 studies, n=1267) was 19% (9-32; range 1-53; I
=96%). Subgroup analysis showed patients with severe COVID-19 had higher rates of abdominal pain (odds ratio OR 7·10 95% CI 1·93-26·07; p=0·003; I
=0%) and abnormal liver function including increased ALT (1·89 1·30-2·76; p=0·0009; I
=10%) and increased AST (3·08 2·14-4·42; p<0·00001; I
=0%) compared with those with non-severe disease. Patients in Hubei province, where the initial COVID-19 outbreak occurred, were more likely to present with abnormal liver functions (p<0·0001) compared with those outside of Hubei. Paediatric patients with COVID-19 had a similar prevalence of gastrointestinal symptoms to those of adult patients. 10% (95% CI 4-19; range 3-23; I
=97%) of patients presented with gastrointestinal symptoms alone without respiratory features. Patients who presented with gastrointestinal system involvement had delayed diagnosis (standardised mean difference 2·85 95% CI 0·22-5·48; p=0·030; I
=73%). Patients with gastrointestinal involvement tended to have a poorer disease course (eg, acute respiratory distress syndrome OR 2·96 95% CI 1·17-7·48; p=0·02; I
=0%).
Our study showed that digestive symptoms and liver injury are not uncommon in patients with COVID-19. Increased attention should be paid to the care of this unique group of patients.
None.
There is a great unmet need for advanced therapies that provide rapid, robust, and sustained disease control for patients with ulcerative colitis. We assessed the efficacy and safety of upadacitinib, ...an oral selective Janus kinase 1 inhibitor, as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis.
This phase 3, multicentre, randomised, double-blind, placebo-controlled clinical programme consisted of two replicate induction studies (U-ACHIEVE induction UC1 and U-ACCOMPLISH UC2) and a single maintenance study (U-ACHIEVE maintenance UC3). The studies were conducted across Europe, North and South America, Australasia, Africa, and the Asia-Pacific region at 199 clinical centres in 39 countries (UC1), 204 clinical centres in 40 countries (UC2), and 195 clinical centres in 35 countries (UC3). Patients aged 16–75 years with moderately to severely active ulcerative colitis (Adapted Mayo score 5–9; endoscopic subscore 2 or 3) for at least 90 days were randomly assigned (2:1) to oral upadacitinib 45 mg once daily or placebo for 8 weeks (induction studies). Patients who achieved clinical response following 8-week upadacitinib induction were re-randomly assigned (1:1:1) to upadacitinib 15 mg, upadacitinib 30 mg, or placebo for 52 weeks (maintenance study). All patients were randomly assigned using web-based interactive response technology. The primary endpoints were clinical remission per Adapted Mayo score at week 8 (induction) and week 52 (maintenance). The efficacy analyses in the two induction studies were based on the intent-to-treat population, which included all randomised patients who received at least one dose of treatment. In the maintenance study, the primary efficacy analyses reported in this manuscript were based on the first 450 (planned) clinical responders to 8-week induction therapy with upadacitinib 45 mg once daily. The safety analysis population in the induction studies consisted of all randomised patients who received at least one dose of treatment; in the maintenance study, this population included all patients who received at least one dose of treatment as part of the primary analysis population. These studies are registered at ClinicalTrials.gov, NCT02819635 (U-ACHIEVE) and NCT03653026 (U-ACCOMPLISH).
Between Oct 23, 2018, and Sept 7, 2020, 474 patients were randomly assigned to upadacitinib 45 mg once daily (n=319) or placebo (n=155) in UC1. Between Dec 6, 2018, and Jan 14, 2021, 522 patients were randomly assigned to upadacitinib 45 mg once daily (n=345) or placebo (n=177) in UC2. In UC3, a total of 451 patients (21 from the phase 2b study, 278 from UC1, and 152 from UC2) who achieved a clinical response after 8 weeks of upadacitinib induction treatment were randomly assigned again to upadacitinib 15 mg (n=148), upadacitinib 30 mg (n=154), and placebo (n=149) in the primary analysis population. Statistically significantly more patients achieved clinical remission with upadacitinib 45 mg (83 26% of 319 patients in UC1 and 114 34% of 341 patients in UC2) than in the placebo group (seven 5% of 154 patients in UC1 and seven 4% of 174 patients; p<0·0001; adjusted treatment difference 21·6% 95% CI 15·8–27·4 for UC1 and 29·0% 23·2–34·7 for UC2). In the maintenance study, clinical remission was achieved by statistically significantly more patients receiving upadacitinib (15 mg 63 42% of 148; 30 mg 80 52% of 154) than those receiving placebo (18 12% of 149; p<0·0001; adjusted treatment difference 30·7% 21·7–39·8 for upadacitinib 15 mg vs placebo and 39·0% 29·7–48·2 for upadacitinib 30 mg vs placebo). The most commonly reported adverse events in UC1 were nasopharyngitis (15 5% of 319 in the upadacitinib 45 mg group vs six 4% of 155 in the placebo group), creatine phosphokinase elevation (15 4% vs three 2%), and acne (15 5% vs one 1%). In UC2, the most frequently reported adverse event was acne (24 7% of 344 in the upadacitinib 45 mg group vs three 2% of 177 in the placebo group). In both induction studies, serious adverse events and adverse events leading to discontinuation of treatment were less frequent in the upadacitinib 45 mg group than in the placebo group (serious adverse events eight 3% vs nine (6%) in UC1 and 11 3% vs eight 5% in UC2; adverse events leading to discontinuation six 2% vs 14 9% in UC1 and six 2% vs nine 5% in UC2). In UC3, the most frequently reported adverse events (≥5%) were worsening of ulcerative colitis (19 13% of 148 in the upadacitinib 15 mg group vs 11 7% of 154 in the upadacitinib 30 mg group vs 45 30% of 149 in the placebo group), nasopharyngitis (18 12% vs 22 14% vs 15 10%), creatine phosphokinase elevation (nine 6% vs 13 8% vs three 2%), arthralgia (nine 6% vs five 3% vs 15 10%), and upper respiratory tract infection (seven 5% vs nine 6% vs six 4%). The proportion of serious adverse events (ten 7% vs nine 6% vs 19 13%) and adverse events leading to discontinuation (six 4% vs ten 6% vs 17 11%) was lower in both upadacitinib groups than in the placebo group. Events of cancer, adjudicated major adverse cardiac events, or venous thromboembolism were reported infrequently. There were no treatment-related deaths.
Upadacitinib demonstrated a positive efficacy and safety profile and could be an effective treatment option for patients with moderately to severely active ulcerative colitis.
AbbVie.
To investigate the seasonal characteristics of submicron aerosol (PM1) in Beijing urban areas, a high‐resolution time‐of‐flight aerosol‐mass‐spectrometer (HR‐ToF‐AMS) was utilized at an urban site in ...summer (August to September 2011) and winter (November to December 2010), coupled with multiple state of the art online instruments. The average mass concentrations of PM1 (60–84 µg m−3) and its chemical compositions in different campaigns of Beijing were relatively consistent in recent years. In summer, the daily variations of PM1 mass concentrations were stable and repeatable. Eighty‐two percent of the PM1 mass concentration on average was composed of secondary species, where 62% is secondary inorganic aerosol and 20% secondary organic aerosol (SOA). In winter, PM1 mass concentrations changed dramatically because of the different meteorological conditions. The high average fraction (58%) of primary species in PM1 including primary organic aerosol (POA), black carbon, and chloride indicates primary emissions usually played a more important role in the winter. However, aqueous chemistry resulting in efficient secondary formation during occasional periods with high relative humidity may also contribute substantially to haze in winter. Results of past OA source apportionment studies in Beijing show 45–67% of OA in summer and 22–50% of OA in winter can be composed of SOA. Based on the source apportionment results, we found 45% POA in winter and 61% POA in summer are from nonfossil sources, contributed by cooking OA in both seasons and biomass burning OA (BBOA) in winter. Cooking OA, accounting for 13–24% of OA, is an important nonfossil carbon source in all years of Beijing and should not be neglected. The fossil sources of POA include hydrocarbon‐like OA from vehicle emissions in both seasons and coal combustion OA (CCOA) in winter. The CCOA and BBOA were the two main contributors (57% of OA) for the highest OA concentrations (>100 µg m−3) in winter. The POA/ΔCO ratios in winter and summer are 11 and 16 µg m−3 ppm−1, respectively, similar to ratios from western cities. Higher OOA/Ox (= NO2 + O3) ratio (0.49 µg m−3 ppb−1) in winter study than these ratios from western cities (0.03–0.16 µg m−3 ppb−1) was observed, which may be due to the aqueous reaction or extra SOA formation contributed by semivolatile organic compounds from various primary sources (e.g., BBOA or CCOA) in Beijing. The evolution of oxygen to carbon ratio (O/C) with photochemical age allows to estimate an equivalent rate constant for chemical aging of OA in summer as kOH ~ 4.1 × 10−12 cm3 molecule−1 s−1, which is of the same order as obtained in other anthropogenic influenced areas and may be useful for OA modeling.
Key Points
PM1 concentrations are consistently high in recent years of Beijing (60 to 85 µg m−3)
Emission sources and formation pathways of aerosol in Beijing are seasonally different
Cooking as nonfossil OA source (13–24%) is important in Beijing
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