52 research outputs found

    An investigation of the effectiveness of vocabulary learning strategies by foreign language students

    Get PDF
    The significance of vocabulary in language acquisition has been acknowledged, as inadequate vocabulary proficiency among learners can impede their progress in acquiring a second language. The primary objective of this study is to analyze and explore the implementation of contemporary techniques for instructing and acquiring vocabulary across students that study foreign language in diverse undergraduate courses. The research goals prompted the selection of a quantitative analysis design as the optimal approach to comprehensively examine the utilization of VLS among the targeted student population. This research employed a questionnaire to examine the circumstances surrounding the acquisition of foreign language vocabulary among an aggregate of 230 undergraduate students. The participants for the study were chosen using a randomized method, and the survey was conducted via an online platform. The findings suggest that this research’s respondents would benefit from additional instruction in Vocabulary Learning Strategies in order to enhance their proficiency with various types of foreign language vocabularies. It is imperative to integrate efficacious strategies for both the acquisition and instruction of vocabulary into the vocabulary learning process of learners

    Downlink Achievable Rate Analysis for FDD Massive MIMO Systems

    Get PDF
    Multiple-Input Multiple-Output (MIMO) systems with large-scale transmit antenna arrays, often called massive MIMO, are a very promising direction for 5G due to their ability to increase capacity and enhance both spectrum and energy efficiency. To get the benefit of massive MIMO systems, accurate downlink channel state information at the transmitter (CSIT) is essential for downlink beamforming and resource allocation. Conventional approaches to obtain CSIT for FDD massive MIMO systems require downlink training and CSI feedback. However, such training will cause a large overhead for massive MIMO systems because of the large dimensionality of the channel matrix. In this dissertation, we improve the performance of FDD massive MIMO networks in terms of downlink training overhead reduction, by designing an efficient downlink beamforming method and developing a new algorithm to estimate the channel state information based on compressive sensing techniques. First, we design an efficient downlink beamforming method based on partial CSI. By exploiting the relationship between uplink direction of arrivals (DoAs) and downlink direction of departures (DoDs), we derive an expression for estimated downlink DoDs, which will be used for downlink beamforming. Second, By exploiting the sparsity structure of downlink channel matrix, we develop an algorithm that selects the best features from the measurement matrix to obtain efficient CSIT acquisition that can reduce the downlink training overhead compared with conventional LS/MMSE estimators. In both cases, we compare the performance of our proposed beamforming method with traditional methods in terms of downlink achievable rate and simulation results show that our proposed method outperform the traditional beamforming methods

    Primary Breast Sarcoma: A Retrospective Single Institution Study of Clinicopathologic Features, Treatment and Prognosis

    Get PDF
    https://openworks.mdanderson.org/sumexp22/1030/thumbnail.jp

    Effect of Mitomycin C on Myopic versus Astigmatic Photorefractive Keratectomy

    Get PDF
    Purpose. Long-term mitomycin C (MMC) effects on photorefractive keratectomy (PRK) were compared in simple myopic and astigmatic patients. Methods. In this observational cohort study, subjects were selected based on preoperative and postoperative data collected from medical records; they were divided into simple myopia with/without MMC and myopic astigmatism with/without MMC groups. Haze, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective refraction, and K-reading were evaluated at 1-, 3-, 6-, and 12-month follow-ups. Results. One hundred fifty-nine eyes of 80 subjects (34 women and 46 men; mean age, 26.81 ± 7.74 years; range, 18–53 years; spherical powers, −0.50 to −8.00 DS; and cylindrical powers, −0.25 to −5.00 DC) were enrolled. One year postoperatively, the simple myopia with/without MMC groups showed no difference in UCVA (P=0.187), BCVA (P=0.163), or spherical equivalent (P=0.163) and a significant difference (P=0.0495) in K-reading; the haze formation difference was nonsignificant (P=0.056). Astigmatic groups with/without MMC showed a significant difference in K-reading (P<0.0001). MMC groups had less haze formation (P<0.0001). Conclusion. PRK with intraoperative MMC application showed excellent visual outcomes. MMC’s effect on astigmatic patients was significantly better with acceptable safety and minimal side effects

    Evaluación de la falla del bracket en relación con diferentes factores en pacientes que reciben tratamiento ortodóntico integral: Un estudio de cohorte retrospectivo.

    Get PDF
    Objective: The aim of this study was to investigate loose brackets in relation to various related factors in orthodontic patients who had completed orthodontic treatment. Material and Methods: In this retrospective study, 738 medical records of patients who had undergone comprehensive orthodontic treatment and matched specific inclusion criteria were selected. Paired t-tests and ANOVA, along with the Mann-Whitney test and Kruskal–Wallis analyses were performed to compare the means of variables between selected subgroups. Results: Loose brackets were found most frequently on premolars, followed by incisors and then canines (p&lt;0.01). Male and young patients were found to have a higher incidence of loose brackets compared to female and adult patients (p=0.044 and p&lt;0.01, respectively). The highest correlation coefficient value was found between treatment duration and total number of loose brackets (0.393), which was statistically significant. Conclusions: The frequency of total number of loose brackets increased with younger age group. Premolar teeth were found to be the most commonly affected teeth, followed by incisors and canines. Mandibular teeth presented more loose brackets than maxillary.Objetivo: Fue investigar brackets sueltos en relación con varios factores relacionados en pacientes ortodónticos que habían completado el tratamiento de ortodoncia. Material y Métodos: En este estudio retrospectivo, se seleccionaron 738 registros médicos de pacientes que se habían sometido a un tratamiento ortodóntico integral y criterios de inclusión específicos coincidentes. Se realizaron pruebas t pareadas y ANOVA, junto con la prueba de Mann-Whitney y los análisis de Kruskal-Wallis para comparar las medias de las variables entre los subgrupos seleccionados. Resultados: Se encontraron corchetes sueltos con mayor frecuencia en los premolares, seguidos de incisivos y luego caninos (p&lt;0.01). Se encontró que los pacientes masculinos y jóvenes tenían una mayor incidencia de corchetes sueltos en comparación con los pacientes femeninos y adultos (p=0.044 y p&lt;0.01, respectivamente). El valor del coeficiente de correlación más alto se encontró entre la duración del tratamiento y el número total de corchetes sueltos (0.393), que fue estadísticamente significativo. Conclusiones: La frecuencia del número total de corchetes sueltos aumentó con el grupo de edad más joven. Los dientes premolares fueron los dientes más afectados, seguidos de los incisivos y los caninos. Los dientes mandibulares presentan más brackets sueltos que los maxilares

    Complexities and complications of extreme obesity

    Get PDF
    Obesity is a common chronic disorder and has detrimental long-term consequences if left untreated. Herein, we report a case of a young lady who suffered from morbid obesity and many of its consequences, and we present a literature review of these complications. While the cause of obesity is multifactorial, the genetic component is particularly important in the pathophysiology of marked obesity. Resistance to Leptin is considered one of the main causes of obesity. There is a unique relationship between polycystic ovary syndrome and obesity, as observed in our case. Obesity is associated with cardiovascular and lung diseases such as heart failure, thromboembolic disease, sleep apnea, and pulmonary hypertension. Our patient had cardiomegaly (730 gm) with eccentric hypertrophy of left and right ventricles. The coronary arteries and aorta were free of atherosclerosis, which is a surprising finding that relates to the mysterious phenomenon of obesity paradox. The terminal event in our young woman was multiple segmental and subsegmental pulmonary arterial thrombi/ thromboemboli superimposed on chronic cardiopulmonary stress due to massive obesity

    Performance Analysis of DoA Estimation for FDD Cell Free Systems Based on Compressive Sensing Technique

    Get PDF
    The concept of cell free (CF) massive MIMO systems is a prospective fifth generation communication technology that effort with base stations for the privilege of user-centric coverage. Most studies on the CF massive MIMO system in the past imply that systems that use time division duplexing (TDD), even despite the systems using frequency division duplex (FDD) predominate in today’s wireless communications. When the number of antennas increases in FDD systems, channel state information (CSI) collection and feedback overhead become major issues. In order to mitigate these issues, we make use of the condition that the so-called uplink and downlink multipath components are comparable. Base station takes use of the angle reciprocity may immediately obtain information on channel parameters from the uplink training signal. In this paper, for CF massive MIMO system based on FDD, we provide compressive sensing (CS) of directions of arrival (DoAs) estimation approach of access point cooperation based on the channel parameters. The suggested estimation approach outperforms the established subspace-based technique, according to simulation findings. Additionally, we showed that the results of our compressive sensing estimator against the conventional estimation method. The former demonstrates way far better outcome and performance accordingly than the latter

    Impairment of IgG Fc functions promotes tumor progression and suppresses NK cell antitumor actions

    Get PDF
    Natural killer (NK) cells mediate antibody dependent cytotoxic killing of cancer cells via cross-linking FcγR on NK cells with IgG-Fc. Studies have shown that the single-hinge cleaved IgGs (scIgGs) have dysfunctional Fc and failed engagement with FcγRs on immune cells. However, little is known about how scIgGs impact on antitumor immunity in the tumor microenvironment. In this study, we revealed a significant association of tumor scIgGs with tumor progression and poor outcomes of breast cancer patients (n = 547). Using multiple mouse tumor models, we demonstrated that tumor scIgGs reduced NK cell cytotoxic activities and resulted in aggressive tumor progression. We further showed that an anti-hinge specific monoclonal antibody (AHA) rescued the dysfunctional Fc in scIgGs by providing a functional Fc and restored NK cell cytotoxic activity. These findings point to a novel immunotherapeutic strategy to enhance Fc engagement with FcγRs for activation of anticancer immunity

    2D nanostructures: Potential in diagnosis and treatment of Alzheimer's disease

    Get PDF
    Two-dimensional (2D) nanomaterials have garnered enormous attention seemingly due to their unusual architecture and properties. Graphene and graphene oxide based 2D nanomaterials remained the most sought after for several years but the quest to design superior 2D nanomaterials which can find wider application gave rise to development of non-graphene 2D materials as well. Consequently, in addition to graphene based 2D nanomaterials, 2D nanostructures designed using macromolecules (such as DNAs, proteins, peptides and peptoids), transition metal dichalcogenides, transition-metal carbides and/or nitrides (MXene), black phosphorous, chitosan, hexagonal boron nitrides, and graphitic carbon nitride, and covalent organic frameworks have been developed. Interestingly, these 2D nanomaterials have found applications in diagnosis and treatment of various diseases including Alzheimer’s disease (AD). Although AD is one of the most debilitating neurodegenerative conditions across the globe; unfortunately, there remains a paucity of effective diagnostic and/or therapeutic intervention for it till date. In this scenario, nanomaterial-based biosensors, or therapeutics especially 2D nanostructures are emerging to be promising in this regard. This review summarizes the diagnostic and therapeutic platforms developed for AD using 2D nanostructures. Collectively, it is worth mentioning that these 2D nanomaterials would seemingly provide an alternative and intriguing platform for biomedical interventions
    corecore