469 research outputs found
A Suboptimal Receiver with Turbo Block Coding for Ultra-Wideband Communications
In this paper, the performance of adaptive equalization and turbo product coding is investigated for pulse-based UWB communications in short-range indoor environments. The sensitivity of adaptive LMS linear and nonlinear (decision-feedback) equalizers with respect to the number of training symbols and number of taps is considered. To reduce the error performance variation with respect to changing channel conditions, a turbo product code (TPC) with two component (31,26,3) Hamming codes is proposed. We report simulation results showing that channel coding not only improves error performance, but also reduces significantly the sensitivity of UWB systems in short-range indoor wireless communications
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Nonlinear dynamics of piezoelectric high displacement actuators in cantilever mode
Experimental results of the nonlinear dynamic response of a piezoelectric high displacement actuator known as thin-layer composite unimorph ferroelectric driver and sensor were compared to a theoretical model, which utilizes the multiple scales method to connect the effective spring constant to higher-order stiffness constants c4 of the piezoelectric layer. This type of actuator has prestress gradients resulting from the manufacturing process that have been reported to play an important role in enhanced actuation. A value of c4=−4.7x1020 N/m2 was obtained for the higher-order lead zirconate titanate (PZT) stiffness coefficient, which is higher than other published results for PZT without prestress gradients. Peak resonance displacements over 1 mm were obtained for even small (100 Vpp) applied fields. The analysis showed a slight voltage dependence that was not specifically accounted for in the theory. This was confirmed by recasting data from other published results and further confirmed by dc offset studies reported here.
Social Work Core Competencies in Disaster Management Practice: An Integrative Review
Purpose: Though social workers are increasingly engaged in the disaster management, there has been a lack of professional guidelines for social work practice and training in this emerging field. This study aims to develop a rudimentary social work competence framework to plug this gap. Method: We conducted an integrative review of 183 international empirical studies and practice reflections, comprising a systematic search, selection, review, and content analysis, guided by ecological systems theory. Results: This rudimentary framework consists of 73 competencies, including 33 micro-level competencies, 18 meso-level ones and 22 macro-level ones, covering knowledge, values and skills in four disaster management phases. Conclusion: Compared to other competence frameworks, this framework further elucidated and classified the salient knowledge, values, and skills in disaster management training and practice for social work
Law and the Body in Joseon Korea: Statecraft and the Negotiation of Ideology
Once considered almost exclusively to be the domain of legal scholars, Joseon dynasty criminal law is recently attracting increasing attention from social, political and intellectual historians of Korea. Despite often reaching opposing conclusions on the characteristics of Joseon legal culture, historians and legal scholars share a strong focus on the dominating role of Confucian ideology. While acknowledging the importance of Confucianism for Joseon statecraft, this paper argues that in actual statecraft and the application of the law, this ideology was negotiated with the perceived needs of the state. The focus of analysis is the relationship between the judicial process—investigation, interrogation and punishment—and cosmological, ideological and cultural notions related to the body. The purpose is to show the tension between the state need to maintain the system and uphold social order (as defined by the state) and the need for the state itself to adhere to the basic principles of the ideology that underpinned this system. Addressing the role of law and punishment in statecraft, the analysis is based on a theoretical framework that combines a conflict-based understanding of society with one that is consensus-based. While on the one hand the violation of notions related to the body was the purport of punishment when dealing with the most severe crimes against the state and its ideology, we can also see how such notions influenced the discourses on penal benevolence, torture and exhumation, whilst partly constituting the reason why some forms of torture were prohibited
Early Troponin I in critical illness and its association with hospital mortality: a cohort study:Early Troponin I in ICU and hospital mortality
Background: Troponin I (TnI) is frequently elevated in critical illness, but its interpretation is unclear. Our primary
objectives in this study were to evaluate whether TnI is associated with hospital mortality and if this association
persists after adjusting for potential confounders. We also aimed to ascertain whether addition of TnI to the Acute
Physiological and Chronic Health Evaluation II (APACHE II) risk prediction model improves its performance in
general intensive care unit (ICU) populations.
Methods: We performed an observational cohort study with independent derivation and validation cohorts in two
general level 3 ICU departments in the United Kingdom. The derivation cohort was a 4.5-year cohort (2010–2014) of
general ICU index admissions (n = 1349). The validation cohort was used for secondary analysis of a prospective
study dataset (2010) (n = 145). The primary exposure was plasma TnI concentration taken within 24 h of ICU admission.
The primary outcome was hospital mortality. We performed multivariate regression, adjusting for components of the
APACHE II model. We derived the risk prediction score from the multivariable model with TnI.
Results: Hospital mortality was 37.3% (n = 242) for patients with detectable TnI, compared with 14.6% (n = 102) for
patients without detectable TnI. There was a significant univariate association between TnI and hospital mortality
(OR per doubling TnI 1.16, 95% CI 1.13–1.20, p < 0.001). This persisted after adjustment for APACHE II model components
(TnI OR 1.05, 95% CI 1.01–1.09, p = 0.003). TnI correlated most strongly with the acute physiology score (APS) component
of APACHE II (r = 0.39). Addition of TnI to the APACHE II model did not improve discrimination (APACHE II concordance
statistic [c-index] 0.835, 95% CI 0.811–0.858; APACHE II + TnI c-index 0.837, 95% CI 0.813–0.860; p = 0.330) or other
measures of model performance.
Conclusions: TnI is an independent predictor of hospital mortality and correlates most highly with the APS component
of APACHE II. It does not improve risk prediction. We would not advocate the adoption of routine troponin analysis on
admission to ICU, and we recommend that troponin be measured only if clinically indicate
Hürthle cell neoplasms of the thyroid: Pathologic outcomes and ultrasonographic analysis
Background: Fine-needle aspiration (FNA) of thyroid nodules suspicious for Hürthle cell neoplasms (HCN) have uncertain rate of malignancy. We aim to characterize rate and predictors of malignancy at our institution and compare these findings with established literature to help guide management.
Methods: Single tertiary-referral center, retrospective study of 166 adults who underwent hemithyroidectomy or total thyroidectomy following FNA suspicious for HCN from 1998-2018. Demographic information and surgical histopathologic results were collected. Preoperative ultrasonography was independently scored on the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) by a board-certified head and neck radiologist.
Results: There were 39 males and 127 females. Overall, 25 (15.1%) patients had carcinoma, with 15 (9%) being Hürthle cell carcinoma (HCC). Men had higher incidence of carcinoma (25.6% v. 11.8%, P = .035), and especially older males. Contralateral carcinoma was seen in 3 of 13 (23.1%) patients that underwent completion thyroidectomy. Patients with carcinoma had larger nodules (average diameter 3.3 cm versus 2.5 cm, respectively, P = .01), but no association with TI-RADS.
Conclusion: Adults with nodules suspicious for HCN have significant risk of malignancy consistent with prior studies. Older males and larger nodule diameter are associated with malignancy in this cohort, but TI-RADS grade is not. These findings provide a framework for management and counseling for lesions suspicious for HCN
The Hong Kong Statement on Practice Research 2017 : Contexts and Challenges of the Far East
This statement on social work practice research highlights the contributions of scholars, practitioners, and conference participants in the Fourth International Conference on Practice Research (ICPR) in 2017, hosted by The Hong Kong Polytechnic University in May 2017. It focuses on the contexts and challenges of carrying out practice research in the Far East and beyond as well as raises pertinent questions about the development of practice research. It begins with a brief description of the context of social work practice research in the Far East. The second part explores the organizational and community contexts and challenges of practice research with special attention to the perspectives of practitioners. It concludes with reviewing some of the continuing challenges that will guide the program planning for the Fifth ICPR in 2020 in Melbourne, Australia, located at the crossroads between East and West.Peer reviewe
Proteome-wide analysis of a malaria vaccine study reveals personalized humoral immune profiles in Tanzanian adults
Tanzanian adult male volunteers were immunized by direct venous inoculation with radiation-attenuated, aseptic, purified, cryopreserved; Plasmodium falciparum; (Pf) sporozoites (PfSPZ Vaccine) and protective efficacy assessed by homologous controlled human malaria infection (CHMI). Serum immunoglobulin G (IgG) responses were analyzed longitudinally using a Pf protein microarray covering 91% of the proteome, providing first insights into naturally acquired and PfSPZ Vaccine-induced whole parasite antibody profiles in malaria pre-exposed Africans. Immunoreactivity was identified against 2239 functionally diverse Pf proteins, showing a wide breadth of humoral response. Antibody-based immune 'fingerprints' in these individuals indicated a strong person-specific immune response at baseline, with little changes in the overall humoral immunoreactivity pattern measured after immunization. The moderate increase in immunogenicity following immunization and the extensive and variable breadth of humoral immune response observed in the volunteers at baseline suggest that pre-exposure reduces vaccine-induced antigen reactivity in unanticipated ways
The association of weather, temperature, and holidays on pediatric maxillofacial trauma
Objective
To evaluate the association of weather, seasons, months and holidays on the frequency and pattern of pediatric facial fractures.
Methods
Retrospective review of pediatric patients treated for facial fractures at two Level I trauma centers in a midsize Midwestern US city over a 5‐year period. Patients were included only if presentation was within 3 hours of inciting trauma, transfers from other facilities were excluded. Demographic characteristics, fracture patterns, operative interventions, weather data, and local public school schedules were acquired and associations were analyzed with unpaired t tests, χ2, multivariate and binomial regression model analyses.
Results
Two hundred and sixty patients were included. The average age (SD) was 11.8 (5.0) years, with 173 males and 87 females. The highest distribution of presentations occurred in the summer season (35.0%), on weekends and holidays (58.1%), and when the weather was described as clear (48.5%). The most common mechanisms of injury were motor vehicle collisions (25.8%), followed by sports—(21.5%) and assault—(16.5%) related injuries. Mechanisms were significantly associated with certain fracture patterns. Older age was associated with fewer orbital fractures (P < .01). Seventy‐five patients (28.8%) required operative intervention. Age was found to impact the likelihood of operative intervention (Exp(β) = 1.081, P = .03) while weather, temperature, and mechanism did not.
Conclusion
Pediatric facial fractures are linked to warmer weather with clear skies and warmer season. Age predicts some fracture patterns and need for operative intervention. These results can be used to inform public health interventions, policymaking, and trauma staffing.
Level of Evidence: Level 2b (retrospective cohort)
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