Miracle-dz/UniFAR-FTUs huggingface dataset:
The parametric spring-mass system, its connection with non-linear optics, and an approach for undergraduate students

The spring-mass system studied in undergraduate physics laboratories may exhibit complex dynamics due to the simultaneous action of gravitational and elastic forces in addition to air friction. In the first part of this paper, we describe a laboratory experiment aimed at beginner students which also gives those with a more advanced background an opportunity to explore more complex aspects of the motions involved. If students are not given predefined apparatus but are allowed instead to design their own set-up for the experiment, they may also learn something about the thought processes and experimental procedures used in physics. In the second part of this paper, we present a systematic study of the parametric behavior of the system because teachers have to master its dynamics. The non-linear interaction between the vertical and the pendular oscillations in a vertical spring-mass system depends on the ratio between the frequencies of the two motions and on the motion's excitation. Systematic experimental investigations, coupled with relevant simulations, highlight the many aspects of physics involved in the partition of energy transfer between the two modes. The different motion waveforms obtained by sweeping through the resonance curve and by applying small and strong excitations are presented and analyzed. The influence of the unavoidable spurious motions is investigated. An analogy between the parametric interaction in a spring--mass system and that found during frequency conversion in non-linear optical crystals is discussed.
The salvage of mesh infection after hernia repair with the use of negative pressure wound therapy (NPWT), a systematic review

Mesh infection is the most feared postoperative complication after abdominal wall hernia repair, often needs mesh removal. Negative pressure wound therapy (NPWT) has been used in these situations with diverse results. The aim of this study was to investigate the efficacy of the NPWT in the treatment of mesh infection, the primary outcome was the mesh salvage rates of different type of meshes and mesh positions.
Probability models for complex systems

This thesis is a collection of essays on probability models for complex systems. Chapter 1 is an introduction to the thesis. The main point made here is the importance of probabilistic modeling to complex problems of machine perception. Chapter 2 studies minimum complexity regression. The results include: (1) weak consistency of the regression, (2) divergence of estimates in $L\sp2$-norm with an arbitrary complexity assignment, and (3) condition on complexity measure to ensure strong consistency. Chapter 3 proposes compositionality as a general principle for probabilistic modeling. The main issues covered here are: (1) existence of general compositional probability measures, (2) subsystems of compositional systems, and (3) Gibbs representation of compositional probabilities. Chapter 4 and 5 establish some useful properties of probabilistic context-free grammars (PCFGs). The following problems are discussed: (1) consistency of estimated PCFGs, (2) finiteness of entropy, momentum, etc, of estimated PCFGs, (3) branching rates and re-normalization of inconsistent PCFGs, and (4) identifiability of parameters of PCFGs. Chapter 6 proposes a probabilistic feature based model for languages. Issues dealt with in the chapter include: (1) formulation of such grammars using maximum entropy principle, (2) modified maximum-likelihood type scheme for parameter estimation, (3) a novel pseudo-likelihood type estimation which is more efficient for sentence analysis. Chapter 7 develops a novel model on the origin of scale invariance of natural images. After presenting the evidence of scale invariance, the chapter goes on to: (1) argue for a 1/$r\sp3$ law of size of object, (2) establish a 2D Poisson model on the origin of scale invariance, and (3) show numerical simulation results for this model. Chapter 8 is a theoretical extension of Chapter 7. A general approach to construct scale and translation invariant distributions using wavelet expansion is formulated and applied to construct scale and translation invariant distributions on the spaces of generalized functions and functions defined on the whole integer lattice.
Melatonin promotes the proliferation of primordial germ cell‐like cells derived from porcine skin‐derived stem cells: A mechanistic analysis

In vitro differentiation of stem cells into functional gametes remains of great interest in the biomedical field. Skin‐derived stem cells (SDSCs) are an adult stem cells that provides a wide range of clinical applications without inherent ethical restrictions. In this paper, porcine SDSCs were successfully differentiated into primordial germ cell‐like cells (PGCLCs) in conditioned media. The PGCLCs were characterized in terms of cell morphology, marker gene expression, and epigenetic properties. Furthermore, we also found that 25 μM melatonin (MLT) significantly increased the proliferation of the SDSC‐derived PGCLCs while acting through the MLT receptor type 1 (MT1). RNA‐seq results found the mitogen‐activated protein kinase (MAPK) signaling pathway was more active when PGCLCs were cultured with MLT. Moreover, the effect of MLT was attenuated by the use of S26131 (MT1 antagonist), crenolanib (platelet‐derived growth factor receptor inhibitor), U0126 (mitogen‐activated protein kinase kinase inhibitor), or CCG‐1423 (serum response factor transcription inhibitor), suggesting that MLT promotes the proliferation processes through the MAPK pathway. Taken together, this study highlights the role of MLT in promoting PGCLCs proliferation. Importantly, this study provides a suitable in vitro model for use in translational studies and could help to answer numerous remaining questions related to germ cell physiology.
Brain mechanisms of automated conflict avoidance simulator supervision

Abstract Supervision of automated systems is an ubiquitous aspect of most of our everyday life activities which is even more necessary in high risk industries (aeronautics, power plants, etc.). Performance monitoring related to our own error making has been widely studied. Here we propose to assess the neurofunctional correlates of system error detection. We used an aviation‐based conflict avoidance simulator with a 40% error‐rate and recorded the electroencephalographic activity of participants while they were supervising it. Neural dynamics related to the supervision of system's correct and erroneous responses were assessed in the time and time‐frequency domains to address the dynamics of the error detection process in this environment. Two levels of perceptual difficulty were introduced to assess their effect on system's error detection‐related evoked activity. Using a robust cluster‐based permutation test, we observed a lower widespread evoked activity in the time domain for errors compared to correct responses detection, as well as a higher theta‐band activity in the time‐frequency domain dissociating the detection of erroneous from that of correct system responses. We also showed a significant effect of difficulty on time‐domain evoked activity, and of the phase of the experiment on spectral activity: a decrease in early theta and alpha at the end of the experiment, as well as interaction effects in theta and alpha frequency bands. These results improve our understanding of the brain dynamics of performance monitoring activity in closer‐to‐real‐life settings and are a promising avenue for the detection of error‐related components in ecological and dynamic tasks.
Nonexpansive mappings and fixed-points in Banach spaces

A subset K of a Banach space B has norma structure [2] if for each bounded convex subset H of K which contains more than one point there is a point x e H which is not a diametral point of H (that is, sup {11 x Y Y e H} (H) ). We proved in an earlier paper [1] that if K is a bounded, nonempty, weakly compact, convex subset of a Banach space B, and if K has normal structure then every nte family of commuting nonexpansive mappings of K into itself has a common fixed-point. (A mapping/ on K is nonexpansive if f(x) f(y) =< x y for each x, y K. ) If the norm of B is strictly convex then this theorem holds for infinite families. (For if the norm is strictly convex then the fixed-point set for each fe is nonempty, bounded, closed and convex. Hence these fixed-point sets are weakly compact and have the finite intersection property; thus there is a point common to all of them.) Although we do not know whether this theorem is true in general for infinite families, we show in this paper that by appropriately strengthening the condition of normal structure we are able to establish the existence of a common fixed-point for arbitrary families without assuming strict convexity of the norm. After proving a consequence of this, an observation is made about characterizations of Hilbert space due to Klee [6] and Phelps [7]. Finally, we show that the stronger version of normal structure introduced in this paper holds in compact convex sets and in closed convex subsets of uniformly convex Banach spaces.
The effect of temperature, humidity, precipitation and cloud coverage on the risk of COVID-19 infection in temperate regions of the USA—A case-crossover study

Background Observations based on the spread of SARS-CoV-2 early into the COVID-19 pandemic have suggested a reduced burden in tropical regions leading to the assumption of a dichotomy between cold and dry and wet and warm climates. Objectives Analyzing more than a whole year of COVID-19 infection data, this study intents to refine the understanding of meteorological variables (temperature, humidity, precipitation and cloud coverage) on COVID-19 transmission in settings that experience distinct seasonal changes. Methods and findings A time stratified case-crossover design was adopted with a conditional Poisson model in combination with a distributed lag nonlinear model to assess the short-term impact of mentioned meteorological factors on COVID-19 infections in five US study sites (New York City (NYC); Marion County, Indiana (MCI); Baltimore and Baltimore County, Maryland (BCM); Franklin County, Ohio (FCO); King County, Washington (KCW)). Higher-than-average temperatures were consistently associated with a decreased relative risk (RR) of COVID-19 infection in four study sites. At 20 degrees Celsius COVID-19 infection was associated with a relative risk of 0.35 (95%CI: 0.20–0.60) in NYC, 1.03 (95%CI:0.57–1.84) in MCI, 0.34 (95%CI: 0.20–0.57) in BCM, 0.52 (95%CI: 0.31–0.87) in FCO and 0.21 (95%CI: 0.10–0.44) in KCW. Higher-than-average humidity levels were associated with an increased relative risk of COVID-19 infection in four study sites. Relative to their respective means, at a humidity level of 15 g/kg (specific humidity) the RR was 5.83 (95%CI: 2.05–16.58) in BCM, at a humidity level of 10 g/kg the RR was 3.44 (95%CI: 1.95–6.01) in KCW. Conclusions The results of this study suggest opposed effects for higher-than-average temperature and humidity concerning the risk of COVID-19 infection. While a distinct seasonal pattern of COVID-19 has not yet emerged, warm and humid weather should not be generally regarded as a time of reduced risk of COVID-19 infections.
Association between the Extent of Peripheral Blood DNA Methylation of HIF3A and Accumulation of Adiposity in community-dwelling Women: The Yakumo Study

ABSTRACT Introduction DNA methylation in the CpG sites of intron 1 of HIF3A is associated with body mass index (BMI). This cross-sectional study investigated correlations between DNA methylation of HIF3A and BMI or adiposity parameters in the Japanese population. Method DNA methylation of HIF3A was quantified via pyrosequencing. Result DNA methylation of HIF3A differed only in women; DNA methylation level at cg27146050 was associated with visceral adipose tissue thickness and correlated with BMI and percent (%) body fat after excluding smokers. Conclusion Peripheral blood DNA methylation at the CpG site (cg27146050) of HIF3A correlated with VAT thickness in Japanese women.
Identification of CKD, bedridden history and cancer as higher-risk comorbidities and their impact on prognosis of hospitalized Omicron patients: a multi-centre cohort study

ABSTRACT To further describe the effect of the “fragile population” and their “higher-risk” comorbidities on prognosis among hospitalized Omicron patients, this observational cohort study enrolled hospitalized patients confirmed with SARS-CoV-2 during the 2022 Omicron wave in Shanghai, China. The primary outcome was progression to severe or critical cases. The secondary outcome was viral shedding time from the first positive SARS-CoV-2 detection. A total of 847 participants were enrolled, most of whom featured as advanced age (>70 years old: 30.34%), not fully vaccinated (55.84%), combined with at least 1 comorbidity (65.41%). Multivariate cox regression suggested age >70 years old (aHR[95%CI] 0.78[0.61–0.99]), chronic kidney disease (CKD) stage 4–5 (aHR[95%CI] 0.61[0.46–0.80]), heart conditions (aHR[95%CI] 0.76[0.60–0.97]) would elongate viral shedding time and fully/booster vaccination (aHR[95%CI] 1.4 [1.14–1.72]) would shorten this duration. Multivariate logistic regression suggested CKD stage 4–5 (aHR[95%CI] 3.21[1.45–7.27]), cancer (aHR[95%CI] 9.52[4.19–22.61]), and long-term bedridden status (aHR[95%CI] 4.94[2.36–10.44]) were the “higher” risk factor compared with the elderly, heart conditions, metabolic disorders, isolated hypertension, etc. for severity while female (aHR[95%CI] 0.34[0.16–0.68]) and fully/booster Vaccination (aHR[95%CI] 0.35[0.12–0.87]) could provide protection from illness progression. CKD stage 4–5, cancer and long-term bedridden history were “higher-risk” factors among hospitalized Omicron patients for severity progression while full vaccination could provide protection from illness progression.
Analysis of risk factors associated with endoscopic retrograde cholangiopancreatography for patients with liver cirrhosis: a multicenter, retrospective, clinical study

Abstract Background: Endoscopic retrograde cholangiopancreatography (ERCP) is the endoscopic modality of choice for the treatment of biliary and pancreatic diseases. However, patients with cirrhosis, particularly those with decompensated cirrhosis, are believed to be at increased risk for complications associated with ERCP. There is a paucity of literature describing the outcomes of ERCP for patients with cirrhosis. This study aimed to investigate the outcomes of ERCP for cirrhosis patients, especially adverse events, and evaluated its safety and efficacy. Methods: We performed a multicenter, retrospective study of all patients at Beijing Friendship Hospital affiliated to Capital Medical University, Xijing Hospital affiliated to Air Force Military Medical University, Beijing Youan Hospital affiliated to Capital Medical University, and the Fifth Medical Center of the People's Liberation Army General Hospital from June 2003 to August 2019. The adverse events of inpatient ERCP for patients with (n = 182) and without liver cirrhosis (controls; n = 385) were compared. Results: A total of 567 patients underwent ERCP between January 2003 and December 2019 were enrolled in this study. Compared to patients without cirrhosis, patients with cirrhosis were at higher risk for postoperative complications (odds ratio [OR], 4.172; 95% confidence interval [CI], 1.232–7.031; P < 0.001) such as postoperative pancreatitis (OR, 2.026; 95% CI, 1.002–4.378; P = 0.001) and cholangitis (OR, 3.903; 95% CI, 1.001–10.038; P = 0.036). The main indications for ERCP for patients with cirrhosis in this study included choledocholithiasis (101 cases; 55.5%), benign bile duct strictures (46 cases; 25.3%), and malignant bile duct strictures (28 cases; 15.4%). Among them, 23 patients (12.6%) underwent balloon dilation and 79 patients (43.4%) underwent sphincterotomy. Of the patients with cirrhosis, delayed bleeding occurred in ten patients (5.5%), postoperative pancreatitis occurred in 80 patients (44.0%), and postoperative cholangitis occurred in 25 patients (13.7%). An additional multivariate analysis showed that the total bilirubin (TBIL) level (OR, 4.58; 95% CI, 2.37–6.70) and Child-Pugh score of C (OR, 3.11; 95% CI, 1.04–5.37) were risk factors for postoperative complications in patients with cirrhosis. Conclusions: Compared with the general population of patients undergoing ERCP, patients with cirrhosis were more prone to postoperative pancreatitis and cholangitis. TBIL levels and Child-Pugh scores were risk factors for postoperative complications in patients with cirrhosis.
Identification and analysis of key microRNAs derived from osteoarthritis synovial fluid exosomes

To the Editor: Osteoarthritis (OA) is one of the most common age-related diseases and is characterized by synovial inflammation and progressive degradation of cartilage. It was reported that one-third of 65-year-olds and 303 million people globally were affected by OA in 2017. Although there is extensive research published on OA, its pathogenesis remains unclear and controversial. Cartilage degeneration is considered a key pathological factor that leads to disease progression. However, an increasing number of studies have revealed that synovial inflammation may be the main driving force for the development of OA. Wang et al suggested that synovial inflammation can accelerate cartilage degeneration by activating the toll-like receptors/myeloid differentiation factor 88/nuclear factor-kB (TLRs/MyD88/NF-kB) signaling pathway. Fibroblast-like synoviocytes (FLSs) can acquire an aggressive proliferative phenotype, driving cartilage and bone destruction. Regardless of which driving factor plays a leading role in OA, communication between FLSs and chondrocytes plays a crucial role. Exosomes (EXs) are vesicles with a diameter of approximately 50 to 150 nm and a lipid bilayer membrane structure. EXs contain many biologically active substances such as non-coding RNAs (ncRNAs), proteins, and messenger RNAs (mRNAs), which play important roles in the cross-talk of OA cells and the intra-articular microenvironment. MicroRNAs (miRNAs) are a group of small ncRNAs approximately 22 nucleotides in length that play key roles in the epigenetics of human diseases by regulating gene expression at the post-transcriptional level. However, few studies have examined differentially expressed miRNAs (DEMs) in synovial fluid (SF)-derived EXs.
Emotion-focused coping mediates the relationship between COVID-related distress and compulsive buying

Background and aims COVID-19 posits psychological challenges worldwide and has given rise to nonadaptive behavior, especially in the presence of maladaptive coping. In the current study, we assessed whether the relationship between COVID-related distress and compulsive buying is mediated by task-focused and emotion-focused coping. We also examined whether these associations were invariant over time as the pandemic unfolded. Methods Self-report surveys were administered online in the United States in the first six months of the pandemic (March–October 2020) in sampling batches of 25 participants every three days, resulting in a total sample of N = 1,418 (40% female, mean age = 36.6). We carried out structural equation modeling to assess whether the relationship between distress related to COVID-19 and compulsive buying is mediated by task-focused and emotion-focused coping. Time was used as a grouping variable based on events related to the pandemic in the U.S. to calculate model invariance across three time periods. Results The results indicated significant mediation between distress, emotion-focused coping, and compulsive buying, but not between task-focused coping and compulsive buying. The mediation model showed excellent fit to the data (χ² = 1119.377, df = 420, RMSEA = 0.059 [0.055–0.064], SRMR = 0.049, CFI = 0.951, TLI = 0.947). Models were not invariant across the three examined time periods. Conclusions Our results indicate that compulsive buying is more likely to occur in relation to emotion-focused coping as a response to COVID-related distress than in relation to task-focused coping, especially during periods of increasing distress. However, model paths varied during the course of the pandemic.
Work, heat and entropy production in bipartite quantum systems

In bipartite quantum systems commutation relations between the Hamiltonian of each subsystem and the interaction impose fundamental constraints on the dynamics of each partition. Here we investigate work, heat and entropy production in bipartite systems characterized by particular commutators between their local Hamiltonians and the interaction operator. We consider the formalism of (Weimer et al 2008 Europhys. Lett. 83 30008), in which heat (work) is identified with energy changes that (do not) alter the local von Neumann entropy, as observed in an effective local measurement basis. We demonstrate the consequences of the commutation relations on the work and heat fluxes into each partition, and extend the formalism to open quantum systems where one, or both, partitions are subject to a Markovian thermal bath. We also discuss the relation between heat and entropy in bipartite quantum systems out of thermal equilibrium, and reconcile the aforementioned approach with the second law of thermodynamics.
Noninvasive prenatal screening in southeast China: clinical application and accuracy evaluation

ABSTRACT Objective To assess the clinical performance of noninvasive prenatal screening (NIPS) for both common trisomy and sex chromosome aneuploidy (SCA). Methods We recruited 71,888 pregnant women to undergo NIPS testing from December 2015 to June 2021. Demographic characteristics, diagnostic results, and follow-up outcomes were collected. Results There were a total of 381 high-risk cases for common trisomy and 343 positive screens for SCA. Invasive prenatal diagnosis (IPD) was performed in 507 (70.0%) participants. The positive predictive value (PPV) was 83.7% for T21, 72.5% for T18, 14.3% for T13, 31.9% for 45,X, 72.0% for 47,XXX, 89.8% for 47,XXY, and 72.2% for 47,XYY, respectively. Logistic regression analysis presented a significant association between Z-score and PPV in common trisomy (P < 0.05) while not in SCA (P > 0.05). PPV in the high-risk group (Z-score ≥ cutoff) was superior to that in the intermediate risk group (3 ≤ Z-score < cutoff) for T21/T18/T13. PPV for 45,X, 47,XXY, and 47,XYY tended to be higher with the increasing Z-score, except for 47,XXX. Conclusions NIPS would be a valuable strategy in prenatal screening, while cautions should be kept in mind for subsequent genetic consulting about the risk of Z-score.