Texas A&M University – Texarkana

The present outbreak of a coronavirus-associated acute respiratory disease called coronavirus disease 19 (COVID-19) is the third documented spillover of an animal coronavirus to humans in only two decades that has resulted in a major epidemic. The Coronaviridae Study Group (CSG) of the International Committee on Taxonomy of Viruses, which is responsible for developing the classification of viruses and taxon nomenclature of the family Coronaviridae, has assessed the placement of the human pathogen, tentatively named 2019-nCoV, within the Coronaviridae. Based on phylogeny, taxonomy and established practice, the CSG recognizes this virus as forming a sister clade to the prototype human and bat severe acute respiratory syndrome coronaviruses (SARS-CoVs) of the species Severe acute respiratory syndrome-related coronavirus, and designates it as SARS-CoV-2. In order to facilitate communication, the CSG proposes to use the following naming convention for individual isolates: SARS-CoV-2/host/location/isolate/date. While the full spectrum of clinical manifestations associated with SARS-CoV-2 infections in humans remains to be determined, the independent zoonotic transmission of SARS-CoV and SARS-CoV-2 highlights the need for studying viruses at the species level to complement research focused on individual pathogenic viruses of immediate significance. This will improve our understanding of virus–host interactions in an ever-changing environment and enhance our preparedness for future outbreaks.

Abstract The present outbreak of lower respiratory tract infections, including respiratory distress syndrome, is the third spillover, in only two decades, of an animal coronavirus to humans resulting in a major epidemic. Here, the Coronavirus Study Group (CSG) of the International Committee on Taxonomy of Viruses, which is responsible for developing the official classification of viruses and taxa naming (taxonomy) of the Coronaviridae family, assessed the novelty of the human pathogen tentatively named 2019-nCoV. Based on phylogeny, taxonomy and established practice, the CSG formally recognizes this virus as a sister to severe acute respiratory syndrome coronaviruses (SARS-CoVs) of the species Severe acute respiratory syndrome-related coronavirus and designates it as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To facilitate communication, the CSG further proposes to use the following naming convention for individual isolates: SARS-CoV-2/Isolate/Host/Date/Location. The spectrum of clinical manifestations associated with SARS-CoV-2 infections in humans remains to be determined. The independent zoonotic transmission of SARS-CoV and SARS-CoV-2 highlights the need for studying the entire (virus) species to complement research focused on individual pathogenic viruses of immediate significance. This research will improve our understanding of virus-host interactions in an ever-changing environment and enhance our preparedness for future outbreaks.

CR Manifolds and the Tangential Cauchy Riemann Complex provides an elementary introduction to CR manifolds and the tangential Cauchy-Riemann Complex and presents some of the most important recent developments in the field. The first half of the book covers the basic definitions and background material concerning CR manifolds, CR functions, the tangential Cauchy-Riemann Complex and the Levi form. The second half of the book is devoted to two significant areas of current research. The first area is the holomorphic extension of CR functions. Both the analytic disc approach and the Fourier transform approach to this problem are presented. The second area of research is the integral kernal approach to the solvability of the tangential Cauchy-Riemann Complex. CR Manifolds and the Tangential Cauchy Riemann Complex will interest students and researchers in the field of several complex variable and partial differential equations.

In this paper, we provide a throughput analysis of the IEEE 802.11 protocol at the data link layer in non-saturated traffic conditions taking into account the impact of both transmission channel and capture effects in Rayleigh fading environment. The impact of both non-ideal channel and capture become important in terms of the actual observed throughput in typical network conditions whereby traffic is mainly unsaturated, especially in an environment of high interference. We extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the buffer of a station. Finally, we derive a linear model of the throughput along with its interval of validity. Simulation results closely match the theoretical derivations confirming the effectiveness of the proposed model.

There has been considerable analysis of buyer‐seller relationship development within the services sector. While a lot of attention has been given to the processes by which relationships are developed, the subject of relationship deterioration is less well researched. Examines the impacts of service failure on the quality of relationships between airlines and their customers who have suffered service failure. In particular, the effects on customers’ trust and commitment to the relationship are studied, the latter being assessed in terms of their willingness to recommend the airline they use to others. Reports on a study of airline customers in the south‐eastern USA which suggests that the impact of a given level of service failure is dependent on the duration to date of a customer’s relationship with the airline they use. However, a non‐linear correlation was found, suggesting that customers experience stages of being initially open‐minded about service failure, followed by lower tolerance of failure, which gradually gives way to a closer relationship which is more resistant to service failure

Abstract The development of effective customer relationships is increasingly recognised as an important component of marketing strategies, particularly in the case of service industries. Developing and maintaining satisfactory customer relationships can help to reduce perceived risk, reduce transactions costs, increase customer loyalty and customer retention and thus impact on organisational performance. From the customer's perspective, the determinants of relationship satisfaction are thought to include factors such as customer orientation, trust, length of relationship, expertise and ethics. Provides further evidence on the cognitive antecedents of relationship satisfaction based on evidence from the financial services sector.

Background: Variations in cardiac troponin concentrations by age, sex, and time between samples in patients with suspected myocardial infarction are not currently accounted for in diagnostic approaches. We aimed to combine these variables through machine learning to improve the assessment of risk for individual patients. Methods: A machine learning algorithm (myocardial-ischemic-injury-index [MI 3 ]) incorporating age, sex, and paired high-sensitivity cardiac troponin I concentrations, was trained on 3013 patients and tested on 7998 patients with suspected myocardial infarction. MI 3 uses gradient boosting to compute a value (0–100) reflecting an individual’s likelihood of a diagnosis of type 1 myocardial infarction and estimates the sensitivity, negative predictive value, specificity and positive predictive value for that individual. Assessment was by calibration and area under the receiver operating characteristic curve. Secondary analysis evaluated example MI 3 thresholds from the training set that identified patients as low risk (99% sensitivity) and high risk (75% positive predictive value), and performance at these thresholds was compared in the test set to the 99th percentile and European Society of Cardiology rule-out pathways. Results: Myocardial infarction occurred in 404 (13.4%) patients in the training set and 849 (10.6%) patients in the test set. MI 3 was well calibrated with a very high area under the receiver operating characteristic curve of 0.963 [0.956–0.971] in the test set and similar performance in early and late presenters. Example MI 3 thresholds identifying low- and high-risk patients in the training set were 1.6 and 49.7, respectively. In the test set, MI 3 values were <1.6 in 69.5% with a negative predictive value of 99.7% (99.5–99.8%) and sensitivity of 97.8% (96.7–98.7%), and were ≥49.7 in 10.6% with a positive predictive value of 71.8% (68.9–75.0%) and specificity of 96.7% (96.3–97.1%). Using these thresholds, MI 3 performed better than the European Society of Cardiology 0/3-hour pathway (sensitivity, 82.5% [74.5–88.8%]; specificity, 92.2% [90.7–93.5%]) and the 99th percentile at any time point (sensitivity, 89.6% [87.4–91.6%]); specificity, 89.3% [88.6–90.0%]). Conclusions: Using machine learning, MI 3 provides an individualized and objective assessment of the likelihood of myocardial infarction, which can be used to identify low- and high-risk patients who may benefit from earlier clinical decisions. Clinical Trial Registration: URL: https://www.anzctr.org.au . Unique identifier: ACTRN12616001441404.

We conducted a preregistered multilaboratory project ( k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result ( d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect ( d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.

The purpose of this study was to investigate the effects of structured physical activity program on social interaction and communication of children with autism spectrum disorder (ASD). Fifty children with ASD from a special school were randomly divided into experimental and control groups. 25 children with ASD were placed in the experimental group, and the other 25 children as the control group participated in regular physical activity. A total of forty-one participants completed the study. A 12-week structured physical activity program was implemented with a total of 24 exercise sessions targeting social interaction and communication of children with ASD, and a quasi-experimental design was used for this study. Data were collected using quantitative and qualitative instruments. SSIS and ABLLS-R results showed that an overall improvement in social skills and social interaction for the experimental group across interim and posttests, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>F</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">8.425</mml:mn></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math> (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.005</mml:mn></mml:math>), and significant improvements appeared in communication, cooperation, social interaction, and self-control subdomains (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.005</mml:mn></mml:math>). Conversely, no statistically significant differences were found in the control group (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>p</mml:mi><mml:mo>&gt;</mml:mo><mml:mn fontstyle="italic">0.005</mml:mn></mml:math>). The study concluded that the special structured physical activity program positively influenced social interaction and communication skills of children with ASD, especially in social skills, communication, prompt response, and frequency of expression.

Conventional digital circuits dissipate a significant amount of energy because bits of information are erased during the logic operations. Thus, if logic gates are designed such that the information bits are not destroyed, the power consumption can be reduced dramatically. The information bits are not lost in case of a reversible computation. This has led to the development of reversible gates. This paper proposes three new reversible logic gates; two of the proposed gates can be employed to design online testable reversible logic circuits. Furthermore, they can be used to implement any Boolean logic function. The application of the reversible gates in implementing several benchmark functions has been presented.

A multilayer neural network based on multivalued neurons (MLMVN) is a neural network with a traditional feedforward architecture. At the same time, this network has a number of specific different features. Its backpropagation learning algorithm is derivative-free. The functionality of MLMVN is superior to that of the traditional feedforward neural networks and of a variety kernel-based networks. Its higher flexibility and faster adaptation to the target mapping enables to model complex problems using simpler networks. In this paper, the MLMVN is used to identify both type and parameters of the point spread function, whose precise identification is of crucial importance for the image deblurring. The simulation results show the high efficiency of the proposed approach. It is confirmed that the MLMVN is a powerful tool for solving classification problems, especially multiclass ones.

ABSTRACT Coronavirus replication is associated with intracellular membrane rearrangements in infected cells, resulting in the formation of double-membrane vesicles (DMVs) and other membranous structures that are referred to as replicative organelles (ROs). The latter provide a structural scaffold for viral replication/transcription complexes (RTCs) and help to sequester RTC components from recognition by cellular factors involved in antiviral host responses. There is increasing evidence that plus-strand RNA (+RNA) virus replication, including RO formation and virion morphogenesis, affects cellular lipid metabolism and critically depends on enzymes involved in lipid synthesis and processing. Here, we investigated the role of cytosolic phospholipase A 2 α (cPLA 2 α) in coronavirus replication using a low-molecular-weight nonpeptidic inhibitor, pyrrolidine-2 (Py-2). The inhibition of cPLA 2 α activity, which produces lysophospholipids (LPLs) by cleaving at the sn -2 position of phospholipids, had profound effects on viral RNA and protein accumulation in human coronavirus 229E-infected Huh-7 cells. Transmission electron microscopy revealed that DMV formation in infected cells was significantly reduced in the presence of the inhibitor. Furthermore, we found that (i) viral RTCs colocalized with LPL-containing membranes, (ii) cellular LPL concentrations were increased in coronavirus-infected cells, and (iii) this increase was diminished in the presence of the cPLA 2 α inhibitor Py-2. Py-2 also displayed antiviral activities against other viruses representing the Coronaviridae and Togaviridae families, while members of the Picornaviridae were not affected. Taken together, the study provides evidence that cPLA 2 α activity is critically involved in the replication of various +RNA virus families and may thus represent a candidate target for broad-spectrum antiviral drug development. IMPORTANCE Examples of highly conserved RNA virus proteins that qualify as drug targets for broad-spectrum antivirals remain scarce, resulting in increased efforts to identify and specifically inhibit cellular functions that are essential for the replication of RNA viruses belonging to different genera and families. The present study supports and extends previous conclusions that enzymes involved in cellular lipid metabolism may be tractable targets for broad-spectrum antivirals. We obtained evidence to show that a cellular phospholipase, cPLA2α, which releases fatty acid from the sn -2 position of membrane-associated glycerophospholipids, is critically involved in coronavirus replication, most likely by producing lysophospholipids that are required to form the specialized membrane compartments in which viral RNA synthesis takes place. The importance of this enzyme in coronavirus replication and DMV formation is supported by several lines of evidence, including confocal and electron microscopy, viral replication, and lipidomics studies of coronavirus-infected cells treated with a highly specific cPLA 2 α inhibitor.

The Au, Ag, and S contents of the glass rims of tholeiitic pillow basalts dredged between 25 degrees N and 30 degrees N on the Mid-Atlantic Ridges are up to 7, 5, and 2.5 times greater, respectively, than those of the crystalline interiors of the basalts. Si, Fe, and Mn are also lower in the crystalline interiors relative to the glass rims, whereas K is higher. The differences in chemical composition between the rims and the interiors are attributed to loss of Au, Ag, S, Si, Fe, and Mn from the interiors of the basaltic pillows due to interaction of the hot basalt with sea water and gain in K by the interiors during subsequent low temperature interactions.Manganese crusts from an area of hydrothermal activity at 26 degrees N have exceptionally low Cu, Ni, Co, Fe contents and low Ir/Au and Ir/Ag ratios when compared to normal hydrogenous crusts that grow away from areas of submarine hydrothermal activity. Only a small fraction of the metals that are lost from the pillow interiors may be transported to the sea floor via the hydrothermal solutions that initially interact with the basalts; the remainder may reside within the basalt pile, for example, in interpillow regions.The Au contents of the fresh crystalline interiors of the basalts correlate with their Cr, Ni, and MgO contents. This suggests that Au in the basalt interiors is hosted by an early-crystallized phase such as Cr-spinel or olivine. The difference in Au content of the fresh interior (hosted by Cr-spinel and/or olivine) and that of the glass rim of the basalt is believed to represent that Au which would have been deposited on loosely bound sites (e.g., deuteric alteration products, grain boundaries, mesostasis phases, and, most important, sulfides within the pillow interior) had it not interacted at a high temperature with sea water.The Au and Ag contents of the glass rims vary by a factor of 10, confirming the existence of regional variations in the Au contents of basalts. The lowest Au and Ag contents in the glass rims are for basalts dredged from an area with no known hydrothermal activity.The results of this study suggest that basalts with high MgO, Cr, Ni, Cu, and Ir contents and low K 2 O and TiO 2 contents may constitute the most favorable type of source basalt. The study demonstrates that the metal available for ore generation in a source rock is not a function of the total metal content of the rock but rather a function of the mineralogical siting of the metal.

The effects of noncontingent matched stimulation (NMS) and response blocking on a boy's stereotypic behavior were evaluated using a multiple schedule that contained three 15-min components (preintervention, intervention, and postintervention). Results showed that stereotypy was always higher after response blocking than before response blocking and was always lower after NMS than before NMS. These results suggest that response blocking may have produced deprivation for the product of stereotypy and that NMS may have provided stimulation that was similar to the product of stereotypy.

This study notes that the lack of convergent and discriminant validity of assessment center ratings in the presence of content-related and criterion-related validity is paradoxical within a unitarian framework of validity. It also empirically demonstrates an application of generalizability theory to examining the convergent and discriminant validity of assessment center dimensional ratings. Generalizability analyses indicated that person, dimension, and person by dimension effects contribute large proportions of variance to the total variance in assessment center ratings. Alternately, exercise, rater, person by exercise, and dimension by exercise effects are shown to contribute little to the total variance. Correlational and confirmatory factor analyses results were consistent with the generalizability results. This provides strong evidence for the convergent and discriminant validity of the assessment center dimension ratings–a finding consistent with the conceptual underpinnings of the unitarian view of validity and inconsistent with previously reported results. Implications for future research and practice are discussed.

Discovering ways to improve student academic performance is a common challenge in the modern classroom. This research study examined the reading habits of sixty-five high school juniors, aged fifteen to seventeen years, at a rural Southeast Texas high school. It was theorized that students who engaged in reading self-selected literature for pleasure would average higher grades in English, mathematics, science, and history than their non-reading peers.

Carry-select adders are one of the faster types of adders. This paper proposes a scheme that encodes the sum bits using two-rail codes; the encoded sum bits are then checked by self-checking checkers. The multiplexers used in the adder are also totally self-checking. The scheme is illustrated with the implementation of a 2-bit carry select adder that can detect all single stuck-at faults on-line; the detection of double faults is not guaranteed. Adders of arbitrary size can be constructed by cascading the appropriate number of such 2-bit adders. A range of adders from 4 to 128 bits is designed using this approach employing a 0.5-mum CMOS technology. The transistor overhead in implementing these self-checking adders varies from 19.51% to 20.94%, and the area overhead varies from 16.07% to 20.67% compared to adders without built-in self-checking capability.

Tumor movements should be accurately predicted to improve delivery accuracy and reduce unnecessary radiation exposure to healthy tissue during radiotherapy. The tumor movements pertaining to respiration are divided into intra-fractional variation occurring in a single treatment session and inter-fractional variation arising between different sessions. Most studies of patients' respiration movements deal with intra-fractional variation. Previous studies on inter-fractional variation are hardly mathematized and cannot predict movements well due to inconstant variation. Moreover, the computation time of the prediction should be reduced. To overcome these limitations, we propose a new predictor for intra- and inter-fractional data variation, called intra- and inter-fraction fuzzy deep learning (IIFDL), where FDL, equipped with breathing clustering, predicts the movement accurately and decreases the computation time. Through the experimental results, we validated that the IIFDL improved root-mean-square error (RMSE) by 29.98% and prediction overshoot by 70.93%, compared with existing methods. The results also showed that the IIFDL enhanced the average RMSE and overshoot by 59.73% and 83.27%, respectively. In addition, the average computation time of IIFDL was 1.54 ms for both intra- and inter-fractional variation, which was much smaller than the existing methods. Therefore, the proposed IIFDL might achieve real-time estimation as well as better tracking techniques in radiotherapy.

In this paper, we provide a saturation throughput analysis of the IEEE 802.11 protocol at the data link layer by including the impact of both transmission channel and capture effects in Rayleigh fading environment. Impacts of both non-ideal channel and capture effects, specially in an environment of high interference, become important in terms of the actual observed throughput. As far as the 4-way handshaking mechanism is concerned, we extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel. This way, any channel model characterizing the physical transmission medium can be accommodated, including AWGN and fading channels. We also extend the Markov model in order to consider the behavior of the contention window when employing the basic 2-way handshaking mechanism. Under the usual assumptions regarding the traffic generated per node and independence of packet collisions, we solve for the stationary probabilities of the Markov chain and develop expressions for the saturation throughput as a function of the number of terminals, packet sizes, raw channel error rates, capture probability, and other key system parameters. The theoretical derivations are then compared to simulation results confirming the effectiveness of the proposed models.

Polymer nanocomposites (PNCs) are a versatile class of materials known for their enhanced mechanical, thermal, electrical, and barrier properties, with the latter referring to resistance against the permeation of gases and liquids. Achieving optimal nanoparticle dispersion within the polymer matrix is essential to fully realizing these advantages. This study investigates strategies for improving nanoparticle dispersion and examines the impact of controlled dispersion on the resulting nanocomposite properties. Various methods, including in situ polymerization, twin screw extrusion, sol–gel processes, nanoparticle surface modification, solution casting, and advanced compounding techniques such as additive manufacturing and self-healing composites were explored to enhance dispersion and improve the compatibility between nanoparticles and polymers. The synergy between improved dispersion and enhanced functionalities—such as increased mechanical strength, thermal stability, conductivity, and chemical resistance—makes these nanocomposites highly valuable for industrial applications in sectors such as the automotive, aerospace, electronics, pharmaceuticals, and packaging industries. The key recommendations based on our findings highlight how customized nanocomposites can address specific industrial challenges, fostering innovation in materials science and engineering.