We consider the scattering of a plane wave by a locally perturbed periodic (with respect to x_1) medium. If there is no perturbation it is usually assumed that the scattered wave is quasi-periodic with the same parameter as the incident plane wave. As it is well known, one can show existence under this condition but not necessarily uniqueness. Uniqueness fails for certain incident directions (if the wavenumber is kept fixed), and it is not clear which additional condition has to be assumed in this case. In this paper we will analyze three concepts. For the Limiting Absorption Principle (LAP) we replace the refractive index n=n(x) by n(x)+iε in a layer of finite width and consider the limiting case when ε tends to zero. This will give an unsatisfactory condition. In a second approach we require continuity of the field with respect to the incident direction. This will give the same satisfactory condition as the third approach where we approximate the incident plane wave by an incident point source and let the location of the source tend to infinity.

Direct and inverse problems for a nonlinear time fractional equation are studied. It is proved that the direct problem has a unique weak solution and the solution depends continuously on the nonlinear coefficient. Then it is shown that the inverse problem has a quasi-solution. The direct problem is solved by method of lines using an operator approach. A quasi-Newton optimization method is used for the numerical solution to the inverse problem. Tikhonov regularization is used to overcome the ill-posedness of the inverse problem. Numerical examples with noise free and noisy data illustrate applicability and accuracy of the proposed method to some extent.

The arterial vascular system exchanges blood gases using pulmonary capabilities. In humans, hemodynamic flows are subjected to periodic velocity modulations. Fluid mechanics and transport of blood gases play an important role in understanding how constitutive relations of the arterial system contribute to human functioning within physiological limits. Assuming the hemodynamic system as a finite dissipative system, the nonlinear evolution equation is perused to understand dynamical challenges under physiological conditions. The infinitesimal component of the vessel wall with concentric thickening in tunica media is considered as a nonaxisymmetric bulge in an elastic-compliant artery. Using the Lie group of transformations method, we discuss the implications of traveling wave solutions to describe their impact on hemodynamic flow in an elastic-compliant artery. We find that cumulative accretion of potential energy contributes to the creation of bright soliton at the apex of the bulge. The wave speed is maximum at the peak of the bulge and progressively retards with the antegrade flow.

MYCN gene plays an important role in neuroblastoma cell growth, apoptosis, differentiation, tumor infiltration, metastasis, and angiogenesis. MYCN gene amplification status in tumor tissue is one of the important clinical indicators of neuroblastoma risk. However, there are several problems in detecting the MYCN gene in tumor tissues, such as complex procedures in detection approaches, high detection costs, and difficulty in obtaining tumor tissues. Studies have shown that circulating-free MYCN gene amplification in neuroblastoma is consistent with that in tumor tissue. Circulating-free MYCN gene amplification has the advantages of high sensitivity, high specificity, simple operation, and non-invasiveness as an indicator for prognosis and recurrence of neuroblastoma. Therefore, the application and future development of circulating-free MYCN gene amplification status in the prognosis and recurrence monitoring of neuroblastoma was examined in this article.

AbstractMachine learning is a growing computational field that borrows concepts and methodologies from statistics and data science to create semi-autonomous programmes capable of adapting to a multitude of problems and decision-making scenarios. With its potential in big data analysis, machine learning is particularly useful for tackling global conservation problems that often involve vast amounts of data and complex interactions between variables. In this systematic review, we summarise the use of machine learning methods in the study of species threats and conservation measures, and their emergent trends. Maximum entropy, Bayesian and ensemble methods have gained wide popularity in the past years and are now commonly used for multiple problems. Their relevance to modern conservation issues (and associated data types), their relatively simple implementation, and availability in a variety of software packages are the most likely factors to explain their popularity. Neural networks, decision trees, support-vector machines and evolutionary algorithms have been used in more specific situations, with some applications showing promise in dealing with increasingly complex data and scenarios.

Background: Following the Coronavirus disease (COVID-19) pandemic, new changes in the transmission of various pathogens have occurred. The environmental changes influenced by the COVID-19 pandemic have affected the flow of human society and the survival environment of other microorganisms. The prevalence of influenza viruses has also changed under this selection pressure. Objective: To investigate the influenza virus’s prevalence, risk factors and symptom characteristics during the outbreak of COVID-19. Methods: Samples and data were collected from outpatients requiring respiratory virus tests in a tertiary hospital. Throat swabs were tested in the immunocolloidal gold method. Characteristics of influenza A and B compared before and after the outbreak of COVID-19. Results: The dominant virus strain in 2020-2022 has gradually changed from influenza A to influenza B. Influenza A is mainly prevalent in 0 to 20 years old (P < 0.05), and influenza B is dominant in all age groups. Most of the patients with positive results were from paediatrics and presented in fever clinics (P < 0.05); Most of the patients were diagnosed with fever and upper respiratory tract infection (P < 0.05). Conclusion: The influenza virus’s positive rate, risk factors and symptom characteristics have changed compared to previous years. It means the epidemic prevention measures have greatly affected the prevalence of the influenza virus since the outbreak of COVID-19.

To reduce the power loss of the SMPA unit, this paper proposes a power equalization RF-PWM method with third and fifth harmonic elimination. Based on the third and fifth harmonic cancellation, this method achieves output power equalization of SMPA by controlling the width of 3-level sub-pulses to be the same. Moreover, the equalization of each switch transistor is realized by outphasing architectures. Finally, the feasibility of the method is verified by simulation results. For QPSK and 16QAM signals with a carrier frequency of 200 MHz, the proposed method achieves the same output power of each SMPA unit.

Prodromes predict attacks of Hereditary Angioedema: results of a prospective StudyTo the Editor,Hereditary Angioedema (HAE) is a lifetime disease characterized by repetitive bouts of tissue edema.1 Early signs, symptoms and perceptions (prodromes) are manifested by subjective and objective signals, preceding attacks by several hours.2-3 Using an new HAE-specific instrument, we have recently shown that patients can identify prodromes and able to predict oncoming attacks.4 However, that study was retrospective, which might have been affected by recall bias.In the present study a cohort of 48 HAE patients prospectively reported four events of prodromes followed by attack, attacks not preceded by a prodrome and incidents with only a prodrome. Pre-defined domains (clusters of body locations) and scalable dimensions (pain, severity, impairment and functionality), time of onset and termination were assessed in each episode.3-4 (Statistical methods are described in the supplementary data ). The study was approved by the ethics committees of Tel-Aviv University, Sheba Medical Center and Barzilai Medical center. All patients signed an informed-consent form. Mean age was 35.25 years (SD ±16.4), Median 30.0 (age range 10-70) and 27 (56.25%) were females. Mean age of onset was 8.3 years and age at diagnosis 10.9 years (2.7 years diagnostic gap) (Table S1 ).We received reports on 119 prodromes and 192 attacks. The majority experienced a prodrome before at least one of their attacks, and 64% affirmed that they can predict an oncoming attack by having a prodrome.(Table S1) .Significant differences were found between prodromes and attacks across all dimensions of the predefined clusters of body locations. Statistical analysis verified that prodromes could be discriminated from attacks for all parameters. (Table 1) Positive correlations were found between the same attributes of prodromes and attacks, most notably in the abdominal and extremity clusters (Table S2, Fig S1A-E) . Mean duration of prodromes was significantly shorter than attacks, and prodromes overlapped the attack in 24.3% of cases. The predictive power analysis indicates that individuals who experience a prodrome had higher risk for having an attack in the same region. Sensitivity of the prodrome as a predictor of attack was 95% to 99%, and specificity 18% to 64%. (Table 2).HAE prodromes represents a continuity of pathophysiologic events, initiated by the activation of the bradykinin-forming cascade and ending with a breach in vascular endothelial integrity.2, 5(Fig S2 ) In this study we aimed to capture the critical elements of prodromes and their association with consequent attacks and evaluate their predictive power as an early warning sign.2-4 The HAE-EPA instrument reliably captures patient’s experience by using the same metrics, and the prospective design better reflects patients’ experience in real-time, which may have been missed in our previous study.The study shades light on the predictive value of prodromes as forecasters of attacks.2-4 It affirms that patients can clearly distinguish prodromes from attacks. The positive correlations support our basic assumption that prodromes could predict attack location and severity, which is particularly germane in the abdomen. In most cases a high intensity attack was predated by a high intensity prodrome. This substantiate our observation on inter-personal differences between subjects4 Mean disease duration of the cohort (27 years) may surmise that the study subjects were experienced patients, who could recognize early pre-attack cues.Treating oncoming attack at the prodromal stage may enhance resolution of attacks.6, 7 Therefore; experienced patients can use prodromes as an efficient strategy in managing attacks by employing early interventions. Such approach can apply in other diseases with relapsing-remitting pattern and advance the concept of prodrome-triggered intervention.8In conclusion , the study ascertained that HAE patients can distinguish prodromes from attacks and a prodrome may predict attack in the same location. Having a prodrome increase the likelihood of subsequent attack, alerting the patients and assisting in early initiation of therapy.Table 1: Within-subject differences between prodrome and attacks

Acquired Amegakaryocytic Thrombocytopenia is a rare hematologic condition, with <50 cases reported. It is characterized by severe thrombocytopenia with complete absence or severe reduction of megakaryocytes in the bone marrow with otherwise normal hematopoiesis. Its mechanism is not fully understood but is suggested to be related to anti-thrombopoietin antibodies.

Gastro-intestinal Stromal Tumors (GISTs), soft tissue sarcomas of the gastrointestinal tract, represent the most frequent malignant gastrointestinal tumors of the subepithelial lesions (SELs) and of mesenchymal gastrointestinal tract. The size of the tumour and its mitotic activity were initially used as risk indicators in determining the prognosis.

In this paper, the potential energy curves of the Λ-S and Ω states of SBr+ are reported for the first time, and the spectrum data of some low excited bound states are obtained. The differences in the spectrum properties of main group molecules and SBr+ were compared and analyzed, providing a sufficient theoretical basis for the subsequent study of main group molecules. The phenomenon of avoided crossing that occurs in the Ω state is analyzed, and finally it is concluded that this phenomenon mainly occurs in the energy region between 20000 cm-1 and 40000 cm-1. Potential transitions in the Ω state capable of achieving laser cooling of SBr+ are explored. The Franck-Condon factor, radiation lifetime and Einstein coefficient between Χ3Σ-0+ and 21Σ+0+ are calculated. From the calculation results, we concluded that direct laser cooling of SBr+ is not feasible. What we have studied in this paper provides a theoretical basis for subsequent computational exploration of the spectrum properties of SBr+.

We examine the price disorder and market efficiency of five cryptocurrencies (Bitcoin, BNB, Cardano, Ethereum, and XRP) before and during COVID-19 pandemic period. Using permutation entropy and Fisher information measure (FIM), we construct the Shannon-Fisher causality plane (SFCP) to map these cryptocurrencies and their respective locations in a two-dimensional plane and then apply sliding time window approach to study the temporal evolution of efficiency. All cryptocurrencies exhibit high but slightly varying informational efficiency during both periods. Cardano is the most efficient. These results might point to the increasing maturity and lower potential for price predictability, which matter to cryp-tocurrencies usage for liquidity risk diversification strategy.

Let $G$ be a graph with $n$ vertices. A vertex–degree–based topological index is defined from a set of real numbers $\{\psi_{ij}\}$ as $$TI(G)=\sum_{1\leq i\leq j\leq n-1}m_{ij}\psi_{ij},$$ where $m_{ij}$ is the number of edges of $G$ connecting a vertex of degree $i$ with a vertex of degree $j$. Many of the well–known topological indices are particular cases of this expression, including all Randi\’{c}-type connectivity indices. In this work we determine extremal values for $TI$ over the set of fluoranthene–type benzenoid systems with a fixed number of edges. The main idea consists in constructing fluoranthene–type benzenoid systems with maximal number of inlets in $\Gamma_{m}$ which have simultaneously minimal number of hexagons, where $\Gamma_{m}$ is the set of fluoranthene–type benzenoid systems with exactly $m(m\geq19)$ edges.

Background: Little information is available regarding the relationship between ascending aortic length and acute aortic events. We aim to evaluate whether patients with acute type A aortic dissection (ATAAD) exhibit differential aortic measurements compared to control patients. Methods: Data were collected on patients with ATAAD and control patients who received imaging for unrelated conditions. Propensity score matching was conducted using age, sex, race, body surface area, and hypertension in the logistic model. After matching, 67 patients remained in each group. Aortic morphometry was assessed via computed tomographic angiography. Ascending aortic length was defined as the centerline distance between the sinotubular junction (STJ) and the origin of the brachiocephalic trunk. Results: The mean ascending aortic length was 76.9 ± 15.7 mm (range 36.8 to 115.0 mm) for patients with ATAAD and was 62.0 ± 10.7 mm (range 34.0 to 87.8 mm) for control patients, which was a significant difference (t=-6.4, P<0.001). ATAAD patients had greater diameter at STJ (median: 41.6 vs 30.2 mm, z=7.5, P<0.001) and diameter at PAB (median: 42.3 vs 32.2 mm, z=6.8, P<0.001) compared with controls. A maximum ascending aortic diameter >5.5 cm (at either the PAB or STJ) was present in 12 of 67 cases (18%) and 0 of 67 controls (P<0.001). Conclusions: Ascending aortic length is significantly greater in patients who experienced ATAAD compared to matched controls. Elongation of the aorta may play a role in the pathogenesis of ATAAD, and assessment of ascending aortic length may be valuable as a predictive marker for aortic events.

A document by Kantash Kumar. Click on the document to view its contents.

Background: Type A aortic dissection (TAAD) involves a tear in the intimal layer of the thoracic aorta proximal to the left subclavian artery, and hence, carries a high risk of mortality and morbidity and requires urgent intervention. This dissection can extend into the main coronary arteries. Coronary artery involvement in TAAD can either be due to retrograde extension of the dissection flap into the coronaries or compression and/or blockage of these vessels by the dissection flap, possibly causing myocardial ischaemia. Due to the emergent nature of TAAD, coronary involvement is often missed during diagnosis, thereby delaying the required intervention. Aims: The main scope of this review is to summarise the literature on the incidence, mechanism, diagnosis, and treatment of coronary artery involvement in TAAD. Methods: A comprehensive literature search was performed using multiple electronic databases, including PubMed, Ovid, Scopus and Embase, to identify and extract relevant studies. Results: Incidence of coronary artery involvement in TAAD was seldom reported in the literature, however, some studies have described patients diagnosed either preoperatively, intraoperatively following aortic clamping, or even during autopsy. Among the few studies that reported on this matter, the treatment choice for coronary involvement in TAAD was varied, with the majority revascularizing the coronary arteries using coronary artery bypass grafting or direct local repair of the vessels. It is well-established that coronary artery involvement in TAAD adds to the already high mortality and morbidity associated with this disease. Lastly, the right main coronary artery was often more implicated than the left. Conclusion: This review reiterates the significance of an accurate diagnosis and timely and effective interventions to improve prognosis. Finally, further large cohort studies and longer trials are needed to reach a definitive consensus on the best approach for coronary involvement in TAAD.

Very few aortic dissections have been published following a heart transplant. Most of these have been reported as donor aortic dissections. Recipient aortic dissection is extremely rare. Here, surgical treatment of chronic Stanford type A recipient aortic dissection in a 40-year-old patient who underwent an orthotopic heart transplant 10 years ago will be discussed in the light of the literature.

Despite advances in technologies and clinical experience, conduction disorders, after TAVR or SAVR, represent the weak point of these procedures, requiring permanent pacemaker implantation (PPI) till 37.7% of patients in TAVR recipients. The role of PPI in TAVR and SAVR remains controversial in mid- and long-term outcomes. Indeed, many studies have been published with contradictory results, leaving doubts rather than certainties.

Four coal samples of different rank were fully characterized with gas (N2 and CO2) sorption and FTIR methods. Then measurements of both equilibrium and kinetics of water vapor adsorption were undertaken at elevated temperatures. Equilibrium and kinetic data were fitted by the modified BET model and the unipore model, respectively. The corresponding thermodynamics, as well as the diffusion activation energy were estimated. The results demonstrate that water vapor adsorption depends on surface chemistry but unrelated to pore structure, because the pore space is not completely filled by water molecules even at saturation pressure. The monolayer capacity decreases with increasing coal rank. Moreover, water vapor needs lower work to attain equilibrium on higher-ranked coal. Also, the binding affinity of water molecule with primary sites is stronger than secondary sites. Furthermore, the diffusion coefficient decreases with coal rank, and the diffusion activation energy for high-volatile bituminous is the highest.

This paper provides an overview of the commodities market, considering three relevant attributes: predictability, similarity, and efficiency. We examine the monthly spot and futures prices time series for 22 commodities from January 1984 until January 2022 with 457 observations. We estimate the permutation entropy (í µí°¸íµí°¸í µí±) and Fisher information measure í µí°¹ í µí± using the Bandt & Pompe method (BPM). We employ the value of these two complexity measures to construct the Shannon-Fisher Causality Plane (SFCP), which allows us to evaluate the disorder and assess the randomness present in the monthly spot and futures prices time series for these commodities. Moreover, we apply í µí°¸íµí°¸í µí± and í µí°¹ í µí± to classify the commodities using complexity hierarchy. We find that the commodities that are located farther from the random ideal position (í µí°¸íµí°¸í µí± = 1, í µí°¹ í µí± = 0) in the SFCP, such as Natural gas, Europe; Iron ore, cfr spot, and Potassium chloride are marked by lower entropy, higher predictability and lower efficiency. In contrast, the commodities that are located near the random ideal position (í µí°¸íµí°¸í µí± = 1, í µí°¹ í µí± = 0) in the SFCP, such as Crude oil-Brent; Crude oil-average, and Silver are characterized by higher entropy, lower predictability and higher efficiency. The K-means algorithm and the hierarchical cluster grouped commodities into only three distinct groups, which is a strong indication that commodity prices have very similar behaviour.

This research explores the multifractal dynamics of the daily number of vaccinated time series for COVID-19, considering six European countries (Belgium, Denmark, France, Ger-many, Greece, and Italy) using the Multifractal Detrended Fluctuations Analysis (MF-DFA). We calculate the multifractal spectrum í µí±“ (í µí»¼) and apply a fourth-degree polynomial regression fit to estimate the complexity parameters that describe the degree of multifractality of the underlying process. We find that the multifractal dynamics of all these countries are characterized by strongly anti-persistent behaviour or anti-persistent long-term correlations (í µí»¼ 0 < 0.5) a lower degree of multifractality, and small fluctuations are dominant in the mul-tifractal spectrum. Our findings shed light on the period of immunization of the population that adhered to the vaccination campaigns is short and that the application of new doses of vaccines must comply with this phenomenology to keep the people safe.

The primary application of codes with locality and availability in distributed storage is for data recovery in case that data are lost on some damaged servers. Locality enables the recovery of lost data by contacting only a restricted number of remaining servers. Availability means that more than one subset of servers providing locality is available for data recovery for each server. The secondary application of these codes in distributed storage is to allow access to hot data in times of high demand. In this paper it is shown that the binary linear [14, 4, 7] code has locality 2 and availability 6 and it can be interpreted as a three-dimensional graph obtained from a [7, 3, 4] Simplex code. It is achieving upper bounds on basic parameters for codes with all-symbols locality and availability. This code can be a building element of more complex codes with scalability inspired by three-dimensional structures. The availability spectrum is introduced as a tool for analyzing codes with locality and availability.

Little is known about the short‐term dynamics of tree water use strategies particularly for neighbouring co-occurring species. Here, we quantify the high frequency changes in water sources and sap flux patterns of two commonly co-occurring tropical rainforest tree species: Dendrocnide photinophylla (Kunth; Chew) and Argyrodendron peralatum (F.M. Bailey; Edlin ex J.H. Boas). A combination of continuous sap flux measurements and hourly sampling of xylem water stable isotope composition (δDand δ 18O) were used to observe water use strategies through a 24 h transpiration cycle. Sap flux ranged from 2.82-28.50 L d -1 and was 66.67% higher in A. peralatum compare to D. photinophylla. For both tree species, sap flux increased with tree size and diurnal sap flux increase resulted in more isotopically enriched xylem water. A Bayesian Mixing Model analysis using sampled soil water isotopic composition from five soil depths from of 0 to 1 m showed that D. photinophyllaused very shallow or surface layer (0-20 cm) water, while A. peralatum sourced its water mostly from deeper in the soil profile (>20 cm). We hypothesize that these differences in species’ water consumption patterns are reated to plant water storage capacity and, wood anatomical features. Our study shows that combning xylem isotope composition and sap flux measurements can help reveal species level water use strategies—useful for improved process understanding for ecohydrological modeling.

IntroductionThe number of students enrolled in online and distance education courses has been increasing since 2000 (Allen & Seaman, 2013). In the fall of 2015, there were 5,954,121 students enrolled in any distance education courses at degree-granting postsecondary institutions (U.S. Department of Education, 2015). This increase in virtual education had brought about pedagogical changes and adaptations that have altered the roles of the educator and learner, and had reshaped the environment in which they interact. According to the 2017 distance enrollment report by theDigital Learning Compass , the number of students who have enrolled in online courses had surpassed six million nationally, continuing a growth trend that has been consistent for 13 years (Allen & Seaman, 2017). Additionally, more than a quarter of higher education students (29.7 percent) in the United States have enrolled in at least one online course (Online Learning Consortium, 2017). The purpose of this study was to examine predictors of success for online learners. To this end, the researchers sought to further understand whether familiarity with and access to technology, employment status, academic readiness are predictors of grade point average and satisfactions for students enrolled in online courses.