On a problem of Henning and Yeo about the transversal number of uniform linear systems whose 2-packing number is fixed

For $r\geq2$, let $(P,\mathcal{L})$ be an $r$-uniform linear system. The transversal number $\tau(P,\mathcal{L})$ of $(P,\mathcal{L})$ is the minimum number of points that intersect every line of $(P,\mathcal{L})$. The 2-packing number $\nu_2(P,\mathcal{L})$ of $(P,\mathcal{L})$ is the maximum number of lines such that the intersection of any three of them is empty. In [Discrete Math. 313 (2013), 959--966] Henning and Yeo posed the following question: Is it true that if $(P,\mathcal{L})$ is a $r$-uniform linear system then $\tau(P,\mathcal{L})\leq\displaystyle\frac{|P|+|\mathcal{L}|}{r+1}$ holds for all $k\geq2$?. In this paper, some results about of $r$-uniform linear systems whose 2-packing number is fixed which satisfies the inequality are given

Mitigating Memorization of Noisy Labels by Clipping the Model Prediction

In the presence of noisy labels, designing robust loss functions is critical for securing the generalization performance of deep neural networks. Cross Entropy (CE) loss has been shown to be not robust to noisy labels due to its unboundedness. To alleviate this issue, existing works typically design specialized robust losses with the symmetric condition, which usually lead to the underfitting issue. In this paper, our key idea is to induce a loss bound at the logit level, thus universally enhancing the noise robustness of existing losses. Specifically, we propose logit clipping (LogitClip), which clamps the norm of the logit vector to ensure that it is upper bounded by a constant. In this manner, CE loss equipped with our LogitClip method is effectively bounded, mitigating the overfitting to examples with noisy labels. Moreover, we present theoretical analyses to certify the noise-tolerant ability of LogitClip. Extensive experiments show that LogitClip not only significantly improves the noise robustness of CE loss, but also broadly enhances the generalization performance of popular robust losses.Comment: Accepted by ICML 202

Results of active surveillance of foodborne diseases in Pudong New Area of Shanghai, 2015-2018

Objective To understand the epidemic trend and characteristics of foodborne diseases caused by specific pathogens in Pudong New Area of Shanghai, so as to provide scientific evidence for disease prevention and control. Methods From 2015 to 2018, the infectious cases with diarrhea as the main complaint were collected from the sentinel hospital of foodborne disease active monitoring in Pudong New Area of Shanghai. Stool or anal swab samples were collected and tested for Vibrio parahaemolyticus, Salmonella, Shigella, diarrheogenic Escherichia coli, Campylobacter jejuni and Norovirus. At the same time, the profiles were collected and analyzed. Results In 2015-2018, 2 871 stool or anal swab samples of diarrhea cases were monitored and collected. The positive rate of pathogens was 23.55% (676/2 871), including Norovirus 20.04% (97/484), diarrheogenic Escherichia coli 11.84% (340/2 871), Campylobacter jejuni 7.21% (68/943), Vibrio parahaemolyticus 4.01% (115/2 871), Salmonella 3.27% (94/2 871) and Shigella 0.28% (8/2 871). The positive rate was higher in the third quarter, showing a significant peak in summer and autumn. Suspicious food was mainly mixed food (41.12%, 278/676), followed by aquatic animals and their products (22.19%, 150/676) and meat and meat products (10.95%, 74/676). Conclusion Norovirus and diarrheogenic Escherichia coli were the main pathogens of diarrhea cases in Pudong New Area of Shanghai. We should further improve the foodborne disease active monitoring system, carry out detailed epidemiological case investigation for specific pathogen positive cases, and provide technical support for effective prevention and control

Intraoperative application of regional cerebral oxygen saturation monitoring for geriatric patients in China: a survey

BackgroundRegional cerebral oxygen saturation (rSO2) monitoring is a real-time and non-invasive technique for estimating the balance of regional cerebral oxygen supply and consumption. Despite the growing popularity of this monitoring technique, data regarding outcome benefits remain sparse and contradictory. This study was conducted to explore the popularity and understanding of cerebral oxygen saturation monitoring during anesthesia in geriatric patients.MethodsAn online self-report questionnaire was distributed in March 2021 to various hospitals in China for dissemination to anesthesiologists. Questions surveyed cerebral oximetry equipment and utilization, demographics, and clinical practice of participants.ResultsIn total, 447 anesthesiologists responded. Of these, 301 (67.3%) respondents reported that their hospitals were equipped with cerebral oximetry, which 274 anesthesiologists use during anesthesia. A high percentage of anesthesiologists chose to monitor rSO2 during cardiac surgery (77.4%, n = 212) and neurosurgery (40.5%, n = 111). Most anesthesiologists agreed that a 30% reduction from the rSO2 baseline requires intervention to avoid cerebral ischemia, mainly via elevating arterial pressure and fraction of inspired oxygen (FiO2). Of those without cerebral oximetry, 138 of 146 (94.5%) anesthesiologists were willing to monitor rSO2. In addition, 291 respondents believed that cerebral oxygen monitoring would help prevent postoperative cognitive dysfunction.ConclusionOur survey indicated that the prevalence of cerebral oximetry remains relatively low, while almost all anesthesiologists expressed their willingness to use rSO2 monitoring in geriatric anesthesia. Heterogeneity in clinical practice was identified, indicating relevant knowledge gaps that should encourage further clinical research to optimize treatment

Effectiveness of WeChat-Group-Based Parental Health Education in Preventing Unintentional Injuries Among Children Aged 0-3: Randomized Controlled Trial in Shanghai

BACKGROUND: Unintentional injuries to children are a major public health problem. The online social media is a potential way to implement health education for caregivers in online communities. Using WeChat, a free and popular social media service in China, this study evaluated the effectiveness of social online community-based parental health education in preventing unintentional injuries in children aged 0-3. METHODS: We recruited 365 parents from two community health centers in Shanghai and allocated them into intervention and control groups randomly. Follow-up lasted for one year. The intervention group received and followed their WeChat group and a WeChat official account for dissemination of reliable medical information. The control group received only the WeChat group. RESULTS: Between the intervention and control groups, changes in unintentional injuries (OR = 1.71, 95% CI: 1.02-2.87, P = .04), preventability (β = 0.344, 95% CI: 0.152-0.537, P \u3c .001), daily supervision behavior (β = 0.503, 95% CI: 0.036-0.970, P = .04), and behaviors for preventing specific injuries (β = 2.198, 95% CI: 1.530-2.865, P \u3c .001) were significantly different, and change in first-aid skills for treating a tracheal foreign body were nearly significant (P = .06). CONCLUSIONS: The WeChat-group-based parental health education can reduce the occurrence of unintentional child injuries by improving parents\u27 skills, beliefs, and behaviors. Online social communities promote health education and reduce unintentional injuries among children. TRIAL REGISTRATION: ChiCTR1900020753. Registered on January 17, 2019

The efficacy and safety of quantitative flow ratio-guided complete revascularization in patients with ST-segment elevation myocardial infarction and multivessel disease: A pilot randomized controlled trial

Background: In patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD), the treatment strategy for non-infarct-related artery (non-IRA) remains controversial. Quantitative flow ratio (QFR) is a new angiography-based physiological assessment index. However, there is little evidence on the practical clinical application of QFR. Methods: Two hundred and twenty-nine patients with STEMI and MVD were recruited for this study. Patients were randomly assigned to either receive QFR-guided complete revascularization (QFR-G-CR) of non-IRA or receive no further invasive treatment. The primary (1º) endpoint analyzed included death due to all causes, non-fatal myocardial infarction (MI), and ischemia-induced revascularization at 12 months post-surgery. Secondary (2º) endpoints included cardiovascular death, unstable angina, stent thrombosis, New York Heart Association (NYHA) class IV heart failure (HF), and stroke at 1 year post surgery. Massive bleeding and contrast-associated acute kidney injury (CAKI) were used as safety endpoints. Results: Around the 12 month follow up, the 1º outcome was recorded in 11/115 patients (9.6%) in the QFR-G-CR population, relative to 23/114 patients (20.1%) in the IRA-only PCI population (hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.22–0.92; p = 0.025). Unstable angina in 6 (5.2%) and 16 (14.0%) patients (HR: 0.36; 95% CI: 0.14–0.92; p = 0.026), respectively. No marked alterations were found in the massive bleeding and CAKI categories. Conclusions: In conclusion, STEMI and MVD patients can benefit from QFR-G-CR of non-IRA lesions in the initial stages of acute MI. This can help reduce incidences of major adverse cardiovascular events and unstable angina, relative to IRA treatment only. Chinese Clinical Trial Registration number: ChiCTR2100044120

Signal-induced Brd4 release from chromatin is essential for its role transition from chromatin targeting to transcriptional regulation

Bromodomain-containing protein Brd4 is shown to persistently associate with chromosomes during mitosis for transmitting epigenetic memory across cell divisions. During interphase, Brd4 also plays a key role in regulating the transcription of signal-inducible genes by recruiting positive transcription elongation factor b (P-TEFb) to promoters. How the chromatin-bound Brd4 transits into a transcriptional regulation mode in response to stimulation, however, is largely unknown. Here, by analyzing the dynamics of Brd4 during ultraviolet or hexamethylene bisacetamide treatment, we show that the signal-induced release of chromatin-bound Brd4 is essential for its functional transition. In untreated cells, almost all Brd4 is observed in association with interphase chromatin. Upon treatment, Brd4 is released from chromatin, mostly due to signal-triggered deacetylation of nucleosomal histone H4 at acetylated-lysine 5/8 (H4K5ac/K8ac). Through selective association with the transcriptional active form of P-TEFb that has been liberated from the inactive multi-subunit complex in response to treatment, the released Brd4 mediates the recruitment of this active P-TEFb to promoter, which enhances transcription at the stage of elongation. Thus, through signal-induced release from chromatin and selective association with the active form of P-TEFb, the chromatin-bound Brd4 switches its role to mediate the recruitment of P-TEFb for regulating the transcriptional elongation of signal-inducible genes.National Natural Science Foundation of China[30930046, 30670408, 81070307]; Natural Science Foundation of Fujian[C0210005, 2010J01231]; Science Planning Program of Fujian Province[2009J1010, 2010J1008]; National Foundation for fostering talents of basic science[J1030626

Picturing Electron Capture to the Continuum in the Transfer Ionization of Intermediate-Energy He²⁺ Collisions with Argon

Electron emission occurring in transfer ionization for He2+ collisions with argon has been investigated using cold target recoil ion momentum spectroscopy. The double differential cross sections for electron capture to the continuum of the projectile (cusp-shaped electrons) are presented for collision energies from 17.5 to 75 keV/u. For an energy of 30 keV/u, we find a maximum in the experimental ratio of the cusp-shaped electron yield to the total electron yield. This result is explained in terms of the velocity matching between the projectile ion and the electron initially bound to the target. One of the important issues for double electron transitions is the role of electron-electron correlation. If this correlation is weak, then the transfer-ionization process can be viewed as two separate sequential processes. If this correlation is strong, then the transfer-ionization process would happen simultaneously and not sequentially. Our experimental and theoretical results indicate that correlation is weak and that the first step is target ionization followed by charge capture

Identification of COVID-19-Specific Immune Markers Using a Machine Learning Method

Notably, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a tight relationship with the immune system. Human resistance to COVID-19 infection comprises two stages. The first stage is immune defense, while the second stage is extensive inflammation. This process is further divided into innate and adaptive immunity during the immune defense phase. These two stages involve various immune cells, including CD4+ T cells, CD8+ T cells, monocytes, dendritic cells, B cells, and natural killer cells. Various immune cells are involved and make up the complex and unique immune system response to COVID-19, providing characteristics that set it apart from other respiratory infectious diseases. In the present study, we identified cell markers for differentiating COVID-19 from common inflammatory responses, non-COVID-19 severe respiratory diseases, and healthy populations based on single-cell profiling of the gene expression of six immune cell types by using Boruta and mRMR feature selection methods. Some features such as IFI44L in B cells, S100A8 in monocytes, and NCR2 in natural killer cells are involved in the innate immune response of COVID-19. Other features such as ZFP36L2 in CD4+ T cells can regulate the inflammatory process of COVID-19. Subsequently, the IFS method was used to determine the best feature subsets and classifiers in the six immune cell types for two classification algorithms. Furthermore, we established the quantitative rules used to distinguish the disease status. The results of this study can provide theoretical support for a more in-depth investigation of COVID-19 pathogenesis and intervention strategies

Dying in the Sun: Direct evidence for elevated UV-B radiation at the end-Permian mass extinction

Land plants can adjust the concentration of protective ultraviolet B (UV-B)-absorbing compounds (UACs) in the outer wall of their reproductive propagules in response to ambient UV-B flux. To infer changes in UV-B radiation flux at Earth's surface during the end-Permian mass extinction, we analyze UAC abundances in ca. 800 pollen grains from an independently dated Permian-Triassic boundary section in Tibet. Our data reveal an excursion in UACs that coincide with a spike in mercury concentration and a negative carbon-isotope excursion in the latest Permian deposits, suggesting a close temporal link between large-scale volcanic eruptions, global carbon and mercury cycle perturbations, and ozone layer disruption. Because enhanced UV-B radiation can exacerbate the environmental deterioration induced by massive magmatism, ozone depletion is considered a compelling ecological driver for the terrestrial mass extinction