Miracle-dz/UniFAR-FTUs huggingface dataset:
Learning Gaussian mixture model with a maximization-maximization algorithm for image classification

The Expectation-Maximization (EM) algorithm is a well known iterative technique for learning a Gaussian Mixture Model (GMM). However, it is not without problems. (i) High computation cost when the number of Gaussians is huge. (ii) Heuristics are required to avoid singularities. (iii) Good initialization is required to avoid poor local maxima. In recent literature, Welling et al [1] suggested other alternatives to EM such as the Expectation-Expectation (EE), Maximization-Expectation (ME) and the Maximization-Maximization (MM) algorithm. Each of them share a trade-off between accuracy and speed. The MM algorithm is the fastest to compute while EE is the most accurate. In particular, the main difference between MM and EM lies in how the GMM latent variable is estimated. In this paper, we develop a new iterative technique for learning GMM based on the MM algorithm, known as the MM-GMM. Implementation only require computing a closed-form equation for GMM parameter and an optimization step for GMM latent variable. We tested our MM-GMM on two image categorization dataset and was able to outperform Kmeans when using vector quantization code such as BoW or VLAD for different cluster sizes.
A Chemical Genomic Screen in Saccharomyces cerevisiae Reveals a Role for Diphthamidation of Translation Elongation Factor 2 in Inhibition of Protein Synthesis by Sordarin

ABSTRACT Sordarin and its derivatives are antifungal compounds of potential clinical interest. Despite the highly conserved nature of the fungal and mammalian protein synthesis machineries, sordarin is a selective inhibitor of protein synthesis in fungal organisms. In cells sensitive to sordarin, its mode of action is through preventing the release of translation elongation factor 2 (eEF2) during the translocation step, thus blocking protein synthesis. To further investigate the cellular components required for the effects of sordarin in fungal cells, we have used the haploid deletion collection of Saccharomyces cerevisiae to systematically identify genes whose deletion confers sensitivity or resistance to the compound. Our results indicate that genes in a number of cellular pathways previously unknown to play a role in sordarin response are involved in its growth effects on fungal cells and reveal a specific requirement for the diphthamidation pathway of cells in causing eEF2 to be sensitive to the effects of sordarin on protein synthesis. Our results underscore the importance of the powerful genomic tools developed in yeast (Saccharomyces cerevisiae) to more comprehensively understanding the cellular mechanisms involved in the response to therapeutic agents.
Active distributed monitoring for dynamic large-scale networks

Networks offering services of high availability and quality need to be carefully monitored. Their increasing size and complexity stresses the ability of currently used static centralized systems. Decentralized approaches are possible and a key issue is the placement of area monitoring stations for optimal operation. Previous research has resulted in computationally expensive algorithms that require a global centralized network view. In this paper we propose a much simpler distributed algorithm and show that it performs as well as existing near-optimal but expensive, centralized algorithms. In addition, we propose that area monitoring stations are mobile agents, cloning and optimally placing themselves by executing the proposed algorithm. As network conditions change, e.g. through faults or persisting congestion, agents can adapt and migrate to new locations. We quantify the benefits of our approach against both the centralized and centrally-computed static distributed approaches.
An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.
Inflammatory Bowel Response against NKT Cells Are Critical for the Initiation of an

We demonstrated in this study the critical role of NKT cells in the lethal ileitis induced in C57BL/6 mice after infection with Toxoplasma gondii . This intestinal inﬂammation is caused by overproduction of IFN- (cid:1) in the lamina propria. The implication of NKT cells was conﬁrmed by the observation that NKT cell-deﬁcient mice (J (cid:2) 281 (cid:3) / (cid:3) ) are more resistant than C57BL/6 mice to the development of lethal ileitis. J (cid:2) 281 (cid:3) / (cid:3) mice failed to overexpress IFN- (cid:1) in the intestine early after infection. This detrimental effect of NKT cells is blocked by treatment with (cid:2) -galactosylceramide, which prevents death in C57BL/6, but not in J (cid:2) 281 (cid:3) / (cid:3) , mice. This protective effect is characterized by a shift in cytokine production by NKT cells toward a Th2 proﬁle and correlates with an increased number of mesenteric Foxp3 lymphocytes. Using chimeric mice in which only NKT cells are deﬁcient in the IL-10 gene and mice treated with anti-CD25 mAb, we identiﬁed regulatory T cells as the source of the IL-10 required for manifestation of the protective effect of (cid:2) -galactosylceramide treatment. Our results highlight the participation of NKT cells in the parasite clearance by shifting the cytokine proﬁle toward a Th1 pattern and simultaneously to immunopathological manifestation when this Th1 immune response remains uncontrolled. The Journal of Immunology, 2005, 175: 899–908.
Sulphur speciation and biogeochemical cycling in long‐term arable cropping of subtropical soils: evidence from wet‐chemical reduction and S K‐edge XANES spectroscopy

Agriculture has claimed a large share of terrestrial environments in the tropics and subtropics through cultivation of native grasslands or forests. The impact of this anthropogenic change on speciation, dynamics, and ecological significance of sulphur (S) compounds is still poorly understood. We combined degradative wet‐chemical reduction and S K‐edge X‐ray absorption near edge structure (XANES) spectroscopy techniques to evaluate the impact of long‐term agricultural management of native grassland soils in South African Highveld on the amount, form and dynamics of S species. Sulphur XANES in the humic substances extracted by 0.1 m NaOH/0.4 m NaF solution showed the presence of strongly reduced (polysulphides, disulphides, thiols, monosulphides and thiophenes), intermediate (sulphoxides and sulphonates) and strongly oxidized (ester sulphates) organic‐S. It showed that strongly oxidized‐S is the predominant form (39–54%) of the total organic‐S in the humic substances, and organic‐S in the intermediate oxidation state represented 30–37% (78–93% of which was attributed to sulphonates). The strongly reduced organic‐S comprised only 17–24% of the total organic‐S. We did not find a close correlation between the results of a degradative wet‐chemical procedure and XANES spectroscopy conducted in both the bulk soils (ester SO4‐S from XANES versus HI‐fractionation, r = 0.27; P < 0.05) and the humic substance extracts (ester SO4‐S from XANES versus HI‐fractionation, r= 0.39; P < 0.05). The ratio of reduced‐S to strongly oxidized‐S (R‐S/O‐S) in the humic substances decreased from 0.61 to 0.21, while the ratio of intermediate‐S to strongly oxidized‐S (I‐S/O‐S) declined from 0.93 to 0.61 after 90 years of arable cropping of the native grassland soils. Hence, there was a shift in oxidation state towards strongly oxidized‐S (+6) and, thereby, a change in the relative proportion of the organic‐S moieties associated with each oxidation state following cultivation of the native grassland soils. Therefore, we conclude that changes in land‐use practice brought about not only quantitative change but also altered the composition of organic‐S functional groups in these native subtropical grassland soils.
Understanding Fiscal Limits and Debt in the Developing Economies of Central America and the Caribbean

This study uses simulations of state dependent distributions of fiscal limits for eighteen (18) economies within Central America and the Caribbean to better understand governments’ ability to service its debt, arising from endogenously determined dynamic Laffer curves. Using a small open economy model to simulate macroeconomic fundamentals and fiscal policy interactions, the empirical findings produced results not previous available for these economies, showing varying and wider distribution of fiscal limits for the open economy model subject to term of trade shocks, indicating that terms of trade volatility impacted the ability of state economies in servicing their debt. It is therefore prudent that policymakers and central bankers consider models that incorporate the use of trade and its volatility, as a robust way of more accurately determining fiscal limits which are a critical component in better understanding governments’ ability to service its debt.
Gapped transformer design methodology and implementation for LLC resonant converters

In the LLC resonant converter, the air gap is generally positioned in the core of the transformer for proper magnetizing inductance. Traditional transformer design methods assume infinite permeability of the core and no energy stored in the core. The improved design methodology for the gapped transformer is proposed with the optimum relative permeability and gap selection to meet the temperature rise and the magnetizing inductance requirements. The magnetizing current influences the magnetic flux in the core leading to the core saturation and core loss, while the resonant current contributes to the winding loss. The transformer design for a 200 W, 90 kHz LLC resonant converter is presented and experimental results validate the proposed methodology.
A Quality Improvement Study Project to Improve Post Cesarean Section Surgical Site Infection Surveillance in a District Hospital in Kigali City

Post-caesarean surgical site infection (PCSI) is one of the most common cesarean section-related complications. In low- and middle-income countries (LMIC), PCSI prevalence is often under-reported and inaccurate because LMIC surveillance systems are often unable to detect PCSIs developed after discharge; this can ultimately wrongly inform the decision-making related to reducing PCSIs.This paper describes the establishment of a post-discharge PCSI surveillance system for identification of PCSI rate in a district hospital in Rwanda.A total of 540 women underwent CS in the hospital from November 2017 to February 2018, and 536 (99.3%) consented to participate in the surveillance. Among those consented, 22 had no telephone and 174 could not be reached by telephone despite multiple attempts. At the end of this study, a total of 340 women completed the entire surveillance period. The total PCSI rate was 11.5%. Out of all PCSIs, 21% were detected during hospitalization period and 79% were detected during the post-discharge period.The PCSI surveillance system developed in this project covered the 30-day period after surgery and provided a more accurate estimate of PCSI rate. The system was able to track PCSIs developed after a patient was discharged from the hospital. Long term sustainability of the project must be evaluated.
Reflexivity and the challenges of collecting sensitive data in India: a research note

As health advertising researchers we become involved with a variety of health and well-being issues in order to advance social marketing research. Health advertising research involves mainly face-to-face encounters with participants using qualitative methodologies. This article explores the challenges a researcher of British origin faced undertaking fieldwork in India in an effort to collect qualitative data about breast cancer awareness (BCA) and prevention, a culturally taboo subject. Key obstacles included cultural barriers, research method assumptions and researcher resilience. Reflexivity has been recognized as a crucial stage in the process of generating knowledge via qualitative research processes. Thereby applying the critical lens of reflexivity, this article reflects upon the complexities of accessing Indian women (a fiercely private demographic) to participate in discussions about the sensitive topic of breast cancer. The results are discussed and recommendations from this researcher’s experience are presented as a resource to assist future qualitative health advertising inquiry
Auditor Tactics in Negotiations: A Research Note

This study provides a broad set of tactics identified and used by mediation experts widely cited in the psychology literature. Seven auditing partners are provided with this broad list of tactics and asked to apply these tactics to two examples of an audit judgment setting. Another group of auditors consisting of 11 partners and 11 managers identify the degree of importance they plan to place on these 38 adapted tactics in the same audit judgment setting. Factor analysis is used to group the tactics into dimensions and it is found that there are four underlying factors. These are contending (forcing/asserting), compromising, problem solving and accommodating. The 22 auditors also manually sort the tactics into groups of homogeneous tactics, and cluster analysis indicates four factors of appealing to authority, forcing/asserting, context setting and facilitating. These groupings from the factor analysis and auditors' sorting are broadly consistent with previous research. Little difference is observed between partners and managers' assessment of the importance of the tactics, while auditors with formal negotiation training place less emphasis on compromising tactics than those without training.
MODULES OVER SUBALGEBRAS OF THE DISK ALGEBRA

This paper deals with the problem of characterizing sub- modules of C(T) over certain subalgebras of the disk algebra A. We obtain results that are analogues of the classical characterizations of sub- spaces of C(T) that are invariant under multiplication by z, i.e., that are submodules over A. These characterizations yield generalizations of Wermer's maximality theorem applicable to these subalgebras. We also present an invariant subspace theorem that seems to be of independent interest and show the equivalence of the classical theorem of the brothers Riesz on analytic measures with the theorem of Fatou.
Validating the organizational climate measure: links to managerial practices, productivity and innovation

This paper describes the development and validation of a multidimensional measure of organizational climate, the Organizational Climate Measure (OCM), based upon Quinn and Rohrbaugh's Competing Values model. A sample of 6869 employees across 55 manufacturing organizations completed the questionnaire. The 17 scales contained within the measure had acceptable levels of reliability and were factorially distinct. Concurrent validity was measured by correlating employees' ratings with managers' and interviewers' descriptions of managerial practices and organizational characteristics. Predictive validity was established using measures of productivity and innovation. The OCM also discriminated effectively between organizations, demonstrating good discriminant validity. The measure offers researchers a relatively comprehensive and flexible approach to the assessment of organizational members' experience and promises applied and theoretical benefits. Copyright © 2005 John Wiley & Sons, Ltd.
Where in the World Are You? Geolocation and Language Identification in Twitter*

The movements of ideas and content between locations and languages are unquestionably crucial concerns to researchers of the information age, and Twitter has emerged as a central, global platform on which hundreds of millions of people share knowledge and information. A variety of research has attempted to harvest locational and linguistic metadata from tweets to understand important questions related to the 300 million tweets that flow through the platform each day. Much of this work is carried out with only limited understandings of how best to work with the spatial and linguistic contexts in which the information was produced, however. Furthermore, standard, well-accepted practices have yet to emerge. As such, this article studies the reliability of key methods used to determine language and location of content in Twitter. It compares three automated language identification packages to Twitter's user interface language setting and to a human coding of languages to identify common sources of disagreement. The article also demonstrates that in many cases user-entered profile locations differ from the physical locations from which users are actually tweeting. As such, these open-ended, user-generated profile locations cannot be used as useful proxies for the physical locations from which information is published to Twitter.
Social Media and Mental Health

There are seemingly opposing findings on social media’s effect on mental well-being. Some studies report no detrimental effects, others no association and others even positive or buffering effects. However, social media has rapidly evolved in a short span of time and so has people’s use of the platforms. Collecting an accurate measure of social media use and other methodological challenges particularly affect data in this area. In this commentary, we discuss two longitudinal studies to elaborate these contracting findings on social media and mental health.
Comparison of T-Spot.TB and tuberculin skin test among silicotic patients

In the present study, T-Spot.TB and the tuberculin skin test (TST) were compared in the screening of latent tuberculosis infection among silicotic patients. A conditional probability model was used to compare the potential clinical utilities of T-Spot.TB and TST performed on 134 silicotic subjects from December 1, 2004 to January 31, 2007. Data from a historical cohort were also reanalysed for further comparison. Agreement with T-Spot.TB was best using a TST cut-off of 10 mm. Age ≥65 yrs independently predicted a tuberculin reaction <10 mm (odds ratio = 3), but not a negative T-Spot.TB response. Lower measures of agreement were observed among current smokers and those aged ≥65 yrs. Tuberculin reaction size was well correlated with both early secretary antigenic target 6 and culture filtrate protein 10 spot counts, except among current smokers. Within the current estimates of sensitivity (88–95%) and specificity (86–99%) for T-Spot.TB, the positive likelihood ratio for T-Spot.TB test would be substantially higher (6.29–95.0 versus 1.65–1.94) and negative likelihood ratio substantially lower (0.05–0.14 versus 0.32–0.41) than the corresponding ratios for the tuberculin test. A low tuberculosis risk differential was similarly observed between tuberculin-negative and untreated tuberculin-positive subjects in the historical cohort. T-Spot.TB is likely to perform better than tuberculin test in the screening of latent tuberculosis infection among silicotic subjects.
A methodology for integrating business process and information infrastructure models

Many organizations today undertake Business Process Reengineering (BPR) and information infrastructure (i.e., network hardware, communications, and applications infrastructure) modernization efforts to drastically reduce costs and improve performance. While these efforts would appear to be mutually supportive and complementary in nature, they are rarely conducted jointly. Although it is known that changes to one of these two facets of the organization can produce significant impacts on the other, analysts and decision-makers have had only limited support for predicting the impacts of change to one or both of these two facets of the enterprise. BPR efforts are generally conducted using business process simulation tools. Information infrastructure modernization efforts are generally conducted using network simulation tools. What is lacking is an integrated method and the automated environment for studying the impacts of change to one of these two as pects of the enterprise on the other. This paper presents a simulation-based methodology enabling simultaneous consideration of changes to core business processes and the infrastructure mechanisms that support those processes.
Hierarchical cooperation for arbitrary wireless networks

We consider the problem of characterizing per node throughput scaling in arbitrary extended wireless networks. Recently, Ozgur, Leveque, and Tse (2007) obtained a complete characterization of throughput scaling for random extended networks (i.e., nodes are placed in a square region uniformly at random) under a fast fading channel model. They proposed a hierarchical cooperative communication scheme to establish this result. However, their results (both the communication scheme and the proof technique) are strongly dependent on the "regularity" induced with high probability by the random node placement. As a main result of this paper, we propose a more general (and very different) hierarchical cooperative communication scheme that works for arbitrarily placed nodes (with a minimum- separation requirement). Under our scheme, we obtain exactly the same per node throughput scaling as in Ozgur et. al., showing that much less regularity is necessary for successful hierarchical cooperation. Our result holds under both fast and slow fading channel model. For small path-loss exponents alpha isin (2,3), we show that our scheme is order optimal for all node placements with minimum-separation requirement. We also show that for certain node placements, our scheme is order optimal for all alpha > 3 as well.
BUILDING AND EXPLOITING INTELLECTUAL CAPITAL : THE ROLE OF SOCIAL , HUMAN AND PHYSICAL RESOURCES *

Data from a field study of 57 technology firms were used to test relationships among physical, human, and social capital to intellectual capital; intellectual capital, in turn, was linked to firm innovation. The results indicate that a firm’s rate of innovation is a function of the level of intellectual capital, which in turn, is predicted based on the level of physical, human, and social capital, and the interaction of these variables with intellectual capital.