Vibrations Levels Assessment of a Robotic Intra-Row Weeder Using Low-Cost Data Acquisition System

Automated weeding is a way to increase efficiency in the control of invasive plants. Soil characteristics can influence the performance of weeder mechanisms. The objective of this work was to determine the vibrations levels of a robotic intra-row weeder mechanism for different operating conditions and provide information to correlate with soil conditions. The data acquisition system was composed of a single-board computer and a triaxial MEMS accelerometer. The computer was programmed in C++ to acquire vibration measurements. The accelerometer was mounted to the bearing housing of the rotary tine shaft. Vibrations of the weeder mechanism were first measured without soil contact for different angular velocities of the rotary tine disk. Then, vibrations were monitored in different soils (dry and moist loam soil and sand) for three angular velocities of rotary tines (25, 50 and 100 rev/min) and two tine depths (25 and 50 mm). RMS accelerations and the frequency spectrum were used to evaluate the vibrations levels. Moist loam soil and sand had the highest and lowest increases in accelerations, respectively. The analysis showed it is possible to correlate vibrational characteristics with soil conditions that may exist during intra-row weeding. In addition, mechanical vibrations in an intra-row weeder can be monitored using a low-cost and user-friendly system

The Mediating Role of Cultural Intelligence in the Relationship Between the Openness to Experience Personality Trait and Job Satisfaction Among Expatriates

This study has explored the role of cultural intelligence as a mediator in the relationship between the openness to experience personality trait and job satisfaction among expatriates. Expatriates were required to fill up online questionnaires to measure all the three variables. This study used a regression and bootstrapping analysis to test the hypothesis in a sample of 265 expatriates. The result indicates that the variance in job satisfaction accountable to the openness to experience personality trait is fully mediated through cultural intelligence. This findingprovides evidence that possessing cultural intelligence acts as a mechanism in which an open expatriate could feel satisfied with his or her job. Moreover, this study discusses the practical implications especially for multinational companies and suggests some future research directions

Work Engagement Influences Affective Commitment: Psychological Capital and Perceived Organisation Support As Moderators

Introduction/Main Objectives: It is well-known that millennials have low levels of attachment towards the organisation.It istherefore necessary to consider ways of retaining them as leavers may affect the organisation financially. Background Problem: Previous studies have consistently shown that work engagement (WE) significantly affects affective com­mitment (AC). However, the correlation level varies. Hence, a moderator could be affecting the strength of their relationship. Novelty: This research investigated whether psychological capital (PsyCap) and perceived organisation support (POS) could act as moderators. Research Methods: The research was a quantitative and non-experimental study. Researchers usingthe convenience sampling technique and the participants were 111 Indonesian millennial employees who completed questionnaires virtually. Findings/Results: Regression analysis confirmed that WE influenced AC significantly and PsyCap was shown to be a moderator. Further, a three-way interaction revealed that a low level of POS has a significant effect,but only when the level of PsyCap is low, implying that POS is still valid as a moderator (even though only partially). Conclusion: This study concluded that both PsyCap and POS are important for millennial employees. Therefore, it is recommended that management consider these two variables when managing the millennials in their organisation

HIV-1 tropism determination using a phenotypic Env recombinant viral assay highlights overestimation of CXCR4-usage by genotypic prediction algorithms for CRRF01_AE and CRF02_AG

Background: Human Immunodeficiency virus type-1 (HIV) entry into target cells involves binding of the viral envelope (Env) to CD4 and a coreceptor, mainly CCR5 or CXCR4. The only currently licensed HIV entry inhibitor, maraviroc, targets CCR5, and the presence of CXCX4-using strains must be excluded prior to treatment. Co-receptor usage can be assessed by phenotypic assays or through genotypic prediction. Here we compared the performance of a phenotypic Env-Recombinant Viral Assay (RVA) to the two most widely used genotypic prediction algorithms, Geno2Pheno([coreceptor]) and webPSSM. Methods: Co-receptor tropism of samples from 73 subtype B and 219 non-B infections was measured phenotypically using a luciferase-tagged, NL4-3-based, RVA targeting Env. In parallel, tropism was inferred genotypically from the corresponding V3-loop sequences using Geno2Pheno([coreceptor]) (5-20% FPR) and webPSSM-R5X4. For discordant samples, phenotypic outcome was retested using co-receptor antagonists or the validated Trofile (R) Enhanced-Sensitivity-Tropism-Assay. Results: The lower detection limit of the RVA was 2.5% and 5% for X4 and R5 minority variants respectively. A phenotype/genotype result was obtained for 210 samples. Overall, concordance of phenotypic results with Geno2Pheno([coreceptor]) was 85.2% and concordance with webPSSM was 79.5%. For subtype B, concordance with Geno2pheno([coreceptor]) was 94.4% and concordance with webPSSM was 79.6%. High concordance of genotypic tools with phenotypic outcome was seen for subtype C (90% for both tools). Main discordances involved CRF01_AE and CRF02_AG for both algorithms (CRF01_AE: 35.9% discordances with Geno2Pheno([coreceptor]) and 28.2% with webPSSM; CRF02_AG: 20.7% for both algorithms). Genotypic prediction overestimated CXCR4-usage for both CRFs. For webPSSM, 40% discordance was observed for subtype A. Conclusions: Phenotypic assays remain the most accurate for most non-B subtypes and new subtype-specific rules should be developed for non-B subtypes, as research studies more and more draw conclusions from genotypically-inferred tropism, and to avoid unnecessarily precluding patients with limited treatment options from receiving maraviroc or other entry inhibitors

Pengaruh Modal Psikologis terhadap Kesejahteraan Subjektif Karyawan Sales Start-Up di PT. X

PT. X merupakan perusahaan start-up yang bergerak di bidang teknologi keuangan. Keberhasilan yang didapat tidak terlepas dari karyawan sales yang menjadi ujung tombak. Karyawan sales menunjukkan berbagai emosi mulai dari emosi positif sampai emosi yang Tidak sedikit pula yang puas atas kehidupannya dan bangga. Hal tersebut disebut sebagai kesejahteraan subjektif. Dalam mengerjakan tugasnya, karyawan sales memiliki keyakinan, mempunyai tujuan, dan merasa optimis akan hidupnya. Kondisi tersebut disebut sebagai modal psikologis. Dengan demikian, penelitian ini dilakukan untuk meneliti pengaruh modal psikologis terhadap kesejahteraan subjektif pada 271 karyawan sales yang bekerja di PT. X. Hipotesis pada penelitian ini adalah modal psikologis memiliki pengaruh secara signifikan terhadap kesejahteraan subjektif pada karyawan sales start-up di PT. X. Teknik sampling yang digunakan adalah convenience sampling. Alat ukur yang digunakan untuk mengukur kesejahteraan subjektif adalah Satisfaction With Life Scale yang dikembangkan oleh Diener dkk. (1985) dan The Positive and Negative Affect Schedule yang dikembangkan oleh Watson dan Clark (1988). Sedangkan untuk modal psikologis menggunakan Psychological Capital Questionnaire dari Luthans dkk. (2007). Hasil regresi menunjukkan bahwa modal psikologis berpengaruh secara signifikan terhadap kesejahteraan subjektif (β=0.630, F=176.779, t=13.296, p0.05)

Network coding for delay challenged environments

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 191-196).Delay is a fundamental problem of data communication and networks, a problem that is not usually addressed in classical coding, information or networking theory. We focus on the general problem of delay challenged networks. This delay challenge may be related to different reasons, for example, 1) large latency, which can affect the performance of the system in delay, throughput or energy efficiency, 2) half-duplex constraints on the nodes, which precludes a node to receive and transmit at the same time, and/or 3) application-level requirements for reliable, fast and efficient dissemination of information. We consider three main problems of study and the role of network coding on solving these problems. The first is related to the problem of reliable communication in time-division duplexing channels, also known as half-duplex channels, in the presence of large latency. In large latency channels, feedback about received packets may lag considerably the transmission of the original packets, limiting the feedback's usefulness. Moreover, the time duplex constraints may entail that receiving feedback may be costly. In this work, we consider tailoring feedback and (network) coding jointly in such settings to reduce the mean delay for successful in order reception of packets. We find that, in certain applications, judicious choices provide results that are close to those that would be obtained with a full-duplex system. The second part of this thesis studies the problem of data dissemination in arbitrary networks. In particular, we study the problem of minimizing the delay incurred in disseminating a finite number of data packets. We show that the optimal solution to the problem can be thought of as a scheduling problem, which is hard to solve. Thus, we consider the use of a greedy linear network coding algorithm that only takes into account the current state of the system to make a decision. The proposed algorithm tries to maximize the impact on the network at each slot, i.e., maximize the number of nodes that will benefit from the coded packet sent by each active transmitter. We show that our scheme is considerably better, in terms of the number of slots to complete transmission, than schemes that choose the node with more information as the transmitter The third part of this work studies the case of underwater acoustic networks as an example of delay challenged networks. We consider the use of network coding under two different lights. First, as a means to obtain a lower bound on the transmission power of multicast connections in underwater networks. Second, to develop practical schemes useful in such networks. Finally, we study upper bounds on the transport capacity of underwater acoustic networks under unicast connections. We show that the amount of information that can be exchanged by each source-destination pair in underwater acoustic networks goes to zero as the number of nodes n goes to infinity. This occurs at least at a rate n-1/Qe-Wo(O(n-k)) where Wo represents the branch zero of the Lambert W function, and a path loss exponent of a. Note that typical values of the path loss exponent are a E [1, 2] for underwater acoustic networks. This is significantly different to the a > 2 of radio wireless applications.by Daniel Enrique Lucani.Ph.D

Prevalence of neural tube defects among pregnant women in Addis Ababa: a community-based study using prenatal ultrasound examination

Purpose The primary aim of this study was to estimate the prevalence of NTDs at ultrasound examination in communities of Addis Ababa and secondarily to provide a description of the dysmorphology of the NTD cases. Methods We enrolled 958 pregnant women from 20 randomly selected health centers in Addis Ababa during the period from October 1, 2018, to April 30, 2019. Of these 958 women, 891 had an ultrasound examination after enrollment, with a special focus on NTDs. We estimated the prevalence of NTDs and compared it with previously reported hospital-based birth prevalence estimates from Addis Ababa. Results Among 891 women, 13 had twin pregnancies. We identified 15 NTD cases among 904 fetuses, corresponding to an ultrasound-based prevalence of 166 per 10,000 (95% CI: 100–274). There were no NTD cases among the 26 twins. Eleven had spina bifida (122 per 10,000, 95% CI: 67–219). Among the 11 fetuses with spina bifida, three had a cervical and one had a thoracolumbar defect while the anatomical site for 7 was not registered. Seven of the 11 spina bifida defects had skin covering, while two of the cervical lesions were uncovered. Conclusion We report a high prevalence of NTDs among pregnancies in communities of Addis Ababa based on screening by ultrasound. The prevalence was higher than in previous hospital-based studies in Addis, and the prevalence of spina bifida was particularly high.publishedVersio

Vitamin D3 supplementation does not enhance the effects of resistance training in older adults

Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. Methods: Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. Results: Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD. Keywords: Cholecalciferol; Muscle plasticity; Strength training. © 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.publishedVersio

Dimension‐independent Markov chain Monte Carlo on the sphere

We consider Bayesian analysis on high-dimensional spheres with angular central Gaussian priors. These priors model antipodally symmetric directional data, are easily defined in Hilbert spaces and occur, for instance, in Bayesian density estimation and binary level set inversion. In this paper we derive efficient Markov chain Monte Carlo methods for approximate sampling of posteriors with respect to these priors. Our approaches rely on lifting the sampling problem to the ambient Hilbert space and exploit existing dimension-independent samplers in linear spaces. By a push-forward Markov kernel construction we then obtain Markov chains on the sphere which inherit reversibility and spectral gap properties from samplers in linear spaces. Moreover, our proposed algorithms show dimension-independent efficiency in numerical experiments

Studi Literatur Digitalisasi Model 5A untuk Pengendalian Obesitas Saat Pandemi COVID-19

The COVID-19 pandemic has had an impact on health regulations made by WHO and the Indonesian Ministry of Health. Recent studies have shown a significant association with self-isolation and behavioral changes such as decreased physical activity and decreased diet with risk of obesity. The existence of social media and mobile apps as a medium of communication can help change lifestyle behaviors and unhealthy diet patterns. The purpose of study was to collect and analize healthcare digitalization articles especially obesity management and 5A model. The study method was literature review. Fulltext Articles was collected from google scholar and pubmed with some keywords such as obesity, epidemiology, COVID-19, pandemic, technology, communication, education, promotion, prevention. The result stated that the digitalization of obesity management with social media and machine learning mobile app could increase patients independence to improve their weight such as behaviour change, lifestyle and dietary pattern