Miracle-dz/UniFAR-FTUs huggingface dataset:
The aerodynamics of insect flight

SUMMARY The flight of insects has fascinated physicists and biologists for more than a century. Yet, until recently, researchers were unable to rigorously quantify the complex wing motions of flapping insects or measure the forces and flows around their wings. However, recent developments in high-speed videography and tools for computational and mechanical modeling have allowed researchers to make rapid progress in advancing our understanding of insect flight. These mechanical and computational fluid dynamic models, combined with modern flow visualization techniques, have revealed that the fluid dynamic phenomena underlying flapping flight are different from those of non-flapping, 2-D wings on which most previous models were based. In particular, even at high angles of attack, a prominent leading edge vortex remains stably attached on the insect wing and does not shed into an unsteady wake, as would be expected from non-flapping 2-D wings. Its presence greatly enhances the forces generated by the wing, thus enabling insects to hover or maneuver. In addition, flight forces are further enhanced by other mechanisms acting during changes in angle of attack, especially at stroke reversal, the mutual interaction of the two wings at dorsal stroke reversal or wing–wake interactions following stroke reversal. This progress has enabled the development of simple analytical and empirical models that allow us to calculate the instantaneous forces on flapping insect wings more accurately than was previously possible. It also promises to foster new and exciting multi-disciplinary collaborations between physicists who seek to explain the phenomenology, biologists who seek to understand its relevance to insect physiology and evolution, and engineers who are inspired to build micro-robotic insects using these principles. This review covers the basic physical principles underlying flapping flight in insects, results of recent experiments concerning the aerodynamics of insect flight, as well as the different approaches used to model these phenomena.
The Optimality and Overuse of Labour in Estonian Manufacturing Enterprises

Transition economies need labour market flexibility for successful restructuring and reallocation of the labour force, and for coping with the requirements of the European Monetary Union. In this paper we apply a novel approach to the issue of labour market flexibility in transition countries by studying the optimality and efficiency of labour usage in Estonian manufacturing enterprises. We employ a dynamic model in which both the long-run optimal level of employment and the speed at which actual employment is adjusted to the optimal are modelled as functions of several variables. Firm-level panel data of 1995-99 were used. The results showed that in the long run, employment responds most strongly to wages, followed by value added and capital stock. The speed of adjustment, labour use optimality and efficiency all show much greater variations over firms than over time. In the course of time, both labour-saving technical change and an increase in the efficiency of labour usage occur. On average, there is shortage of labour compared to firms' own optimal level, along with overuse of labour compared to best-practice technology. Capital seems to be a binding constraint on the development of employment in the Estonian labour market. Copyright (c) The European Bank for Reconstruction and Development, 2004.
Presence Equation: An Investigation into Cognitive Factors Underlying Presence

The relationship between presence and cognitive factors such as absorption, creative imagination, empathy, and will ingness to experience presence was investigated. Presence was defined, operationalized, and measured using a ques tionnaire that we devised. Absorption and creative imagina tion were measured using questionnaires developed in the area of hypnosis, and empathy was assessed through an interpersonal reactivity index. Results indicated significant correlations between presence and each cognitive factor. They showed that persons who are highly fantasy prone, more empathic, more absorbed, more creative, or more willing to be transported to the virtual world experienced a greater sense of presence. Regression analysis led to a pres ence equation, which could be used to predict presence based on the investigated cognitive factors. Findings are congruent with user characteristics presented by the pres ence literature and support the position that individual dif ferences are important for the study of presence.
Prevention of the development of heart failure with preserved ejection fraction by the phosphodiesterase‐5A inhibitor vardenafil in rats with type 2 diabetes

Heart failure with preserved ejection fraction (HFpEF) has a great epidemiological burden. The pathophysiological role of cyclic guanosine monophosphate (cGMP) signalling has been intensively investigated in HFpEF. Elevated levels of cGMP have been shown to exert cardioprotective effects in various cardiovascular diseases, including diabetic cardiomyopathy. We investigated the effect of long‐term preventive application of the phosphodiesterase‐5A (PDE5A) inhibitor vardenafil in diabetic cardiomyopathy‐associated HFpEF.
Sparse Weighted Voting Classifier Selection and its LP Relaxations

We consider a combinatorial optimization problem that generalizes the minimum disagreement halfspace problem; we seek to minimize the number of misclassifications of a weighted voting classifier, plus a penalty proportional to the density of the vector of weights. To justify the use of this optimization problem, we investigate its relation to the minimum description length principle and statistical learning theory generalization bounds. We prove that the optimum is at least as hard to approximately compute as minimum disagreement halfspace for a large class of penalty parameters. After formulating the problem as a mixed integer program (MIP), we show that common “soft margin” linear programming formulations for constructing weighted voting classsifiers are equivalent to an LP relaxation of our formulation. We illustrate that the LP relaxation can be very weak, with an exponential lower bound on the potential intergrality gap. We then prove that augmenting the optimization problem with certain simple valid inequalities tightens the relaxation considerably, yielding a linear upper bound on the gap for all values of the penalty parameter that exceed a sensible lower bound. Acknowledgements: This material is based upon work funded in part by the U.S. Department of Homeland Security under Grant Award Number 2008-DN-077-ARI001-02. We thank Rob Schapire for helpful discussions. The first author would also like to thank Kristin Bennett for her comments during earlier stages of this work, Martin Milanic for his comments regarding a related feature selection problem, and participants of the Operations Research seminar at the Technion for their comments.
Time-domain method for tracking dispersive channels in MIMO OFDM systems

In this paper we address the problem of channel estimation for multiple-input multiple-output OFDM systems for mobile users. Channel tracking and equalization method stemming from Kalman filtering is proposed for time-frequency selective channels. Tracking of MIMO channel matrix is performed in time-domain and equalization in frequency domain. Applying the matrix inversion lemma significantly reduces computational complexity. Simulation results are presented using realistic channel model in typical urban scenarios.
Eph/Ephrin-mediated Mesenchymal Stem Cell Regulation of T-cell Activation and Function

Mesenchymal stem cells (MSC) represent a promising cellular therapy for the treatment of immune-related conditions due to their immunomodulatory properties, which include the capacity to inhibit the proliferation and function of T-cells. Despite the fact that MSC have been the subject of intense investigation as therapeutic agents for diseases in which cellular immune response is exacerbated, the underlying mechanisms of how MSC exert their T cell suppressive properties remain to be fully understood. Eph surface tyrosine kinase receptors and their ephrin ligands are involved in T-cell development, maturation, activation and proliferation. Recent findings have demonstrated Eph/ephrin interactions as potential mechanisms mediating human MSC inhibition of activated T-cells. Here we highlight the influence of Eph and ephrin molecules in the communication between MSC and T-cells that result in T-cell suppression by MSC.
Communication with tokens in repeated games on networks

A key obstacle to coordination and cooperation in many networked environments is that behavior in each bilateral relationship is not observable to individuals outside that relationship: that is, information is local. This paper investigates when players can use communication to replicate any outcome that would have been sustainable were this information public. A benchmark result is that if only cheap talk communication is possible then public information can only be replicated if the network is 2-connected: that is, if no player can prevent the flow of information to another. In contrast, the main result is that public information can always be replicated if in addition to cheap talk the players have access to undifferentiated tokens that can be freely transferred among neighbors (which bear some resemblance to certain models of fiat money). Sufficient conditions are provided for such tokens to expand the equilibrium payoff set, relative to what would be achievable without explicit communication or with cheap talk communication only.
CD47 Mediates Killing of Breast Tumor Cells via Gi-Dependent Inhibition of Protein Kinase A

Thrombospondins (TSPs) have been implicated as antitumor and antimetastasis factors in breast cancer. Although this effect has been attributed to the antiangiogenic activity of TSPs, recent observations suggest other mechanisms may be at work. The TSP receptor CD47 (integrin-associated protein) has recently been reported to mediate a novel form of apoptosis. Here, we have studied the response of breast cancer cells to CD47 ligands TSP-1, the CD47 agonist peptide 4N1K derived from TSP-1, and the anti-CD47 monoclonal antibody 1F7. All of these ligands killed four different breast cancer cell lines. This CD47-mediated cell death did not require active caspases or Bcl-2 degradation and did not cause DNA laddering or cytochrome c release. Pertussis toxin (PTX) prevented CD47-mediated death, indicating the involvement of Giα. 4N1K dramatically reduced intracellular cAMP levels, an effect reversed with PTX. Forskolin, 8-bromo cAMP, and isobutylmethylxanthine (IBMX) all prevented CD47-mediated apoptosis, indicating the involvement of cAMP. H89 and protein kinase A (PKA) inhibitor peptide prevented rescue of breast cancer cells by PTX, 8-Br-cAMP, and forskolin, suggesting that the effects of cAMP are mediated via PKA-dependent phosphorylation events. Epidermal growth factor also inhibited CD47-induced apoptosis via a PKC-dependent but ERK-independent pathway. Thus, CD47-mediated killing of breast cancer cells occurs by a novel pathway involving regulation of cAMP levels by heterotrimeric Gi with subsequent effects mediated by PKA.
Financial Institutions Center Measurement and Estimation of Credit Migration Matrices

Credit migration matrices are cardinal inputs to many risk management applications. Their accurate estimation is therefore critical. We explore three approaches, cohort and two variants of duration – time homogeneous and non-homogeneous -and the resulting differences, both statistically through matrix norms and economically through credit portfolio and credit derivative models. We develop a testing procedure to assess statistically the differences between migration matrices using bootstrap techniques. The method can have substantial economic import: economic credit risk capital differences between economic regimes, recession vs. expansion, can be as large as difference implied by different estimation techniques. Ignoring the efficiency gain inherent in the duration methods by using the cohort method instead is more damaging that making a (possibly false) assumption of timehomogeneity.
Alterations in mGluR5 Expression and Signaling in Lewy Body Disease and in Transgenic Models of Alpha-Synucleinopathy – Implications for Excitotoxicity

Dementia with Lewy bodies (DLB) and Parkinson's Disease (PD) are neurodegenerative disorders of the aging population characterized by the abnormal accumulation of alpha-synuclein (alpha-syn). Previous studies have suggested that excitotoxicity may contribute to neurodegeneration in these disorders, however the underlying mechanisms and their relationship to alpha-syn remain unclear. For this study we proposed that accumulation of alpha-syn might result in alterations in metabotropic glutamate receptors (mGluR), particularly mGluR5 which has been linked to deficits in murine models of PD. In this context, levels of mGluR5 were analyzed in the brains of PD and DLB human cases and alpha-syn transgenic (tg) mice and compared to age-matched, unimpaired controls, we report a 40% increase in the levels of mGluR5 and beta-arrestin immunoreactivity in the frontal cortex, hippocampus and putamen in DLB cases and in the putamen in PD cases. In the hippocampus, mGluR5 was more abundant in the CA3 region and co-localized with alpha-syn aggregates. Similarly, in the hippocampus and basal ganglia of alpha-syn tg mice, levels of mGluR5 were increased and mGluR5 and alpha-syn were co-localized and co-immunoprecipated, suggesting that alpha-syn interferes with mGluR5 trafficking. The increased levels of mGluR5 were accompanied by a concomitant increase in the activation of downstream signaling components including ERK, Elk-1 and CREB. Consistent with the increased accumulation of alpha-syn and alterations in mGluR5 in cognitive- and motor-associated brain regions, these mice displayed impaired performance in the water maze and pole test, these behavioral alterations were reversed with the mGluR5 antagonist, MPEP. Taken together the results from study suggest that mGluR5 may directly interact with alpha-syn resulting in its over activation and that this over activation may contribute to excitotoxic cell death in select neuronal regions. These results highlight the therapeutic importance of mGluR5 antagonists in alpha-synucleinopathies.
Teachers' Knowledge about Attention Deficit Hyperactivity Disorder among Primary School Children

Teachers can play a key role in identifying and supporting students with attention deficit hyperactivity disorder. In order to achieve this role, it is vital for teachers to have obvious knowledge about this disorder. Aim of the study was to identify teachers' knowledge about attention deficit hyperactivity disorder among primary school children. Design: a cross sectional analytic design was used. Setting: this study was conducted at primary schools in two villages (El Batanon & Kafr-Tunbdy) at Shebin El Koum Distric, Menoufia Governorate. Simple random sample consisted of 500 teachers from primary schools were included. Tools: I. Structured interview questionnaire which included socio demographic data, experience and training of teachers about attention deficit hyperactivity disorder. II. Knowledge of attention deficit disorders scale. The main results of study reported that 81.4% of teachers had not received any training courses during college about attention deficit hyperactivity disorder. Also, there was 59% of teachers had poor knowledge compared to only 10.2% had good knowledge about attention deficit hyperactivity disorder. Furthermore, there was significant relation between mean score of total teachers' knowledge about attention deficit hyperactivity disorder and their age, marital status, education qualification, teaching experience years, receiving training courses during college and attending an in-service workshop about attention deficit hyperactivity disorder. Conclusion: knowledge of teachers in the studied sample was very poor and insufficient about attention deficit hyperactivity disorder. Also, most of teachers did not have any training courses during college and did not attend an in-service workshop about attention deficit hyperactivity disorder. Recommendations: In-service training courses to teachers about attention deficit hyperactivity disorder. Enhance teachers, parents and community awareness about attention deficit hyperactivity disorder through mass media.
Student Cognitive Styles in Postsecondary Technology Programs.

Much of the published research on cognitive styles focuses on the differences in cognitive styles of students pursuing different majors in either a four year institution or a two year institution. For example, Witkin, et al. (1977) conducted a ten year longitudinal study in four year institutions which sought to determine if field dependence/independence was related to a student's (1) initial major choice (science, education, and other) and final degree major and (2) achievement in various major courses. The study determined that the selection of a major was influenced by cognitive styles and that students who initially selected majors that required a particular cognitive style which was different than their own were more likely to change to a major which complemented their cognitive style. The study also found a tendency for students to receive higher grades in fields that were compatible with their cognitive style. Frank (1986) found that field dependence/independence of female education majors varied depending on the particular area of specialization within an education major (home economics, nursing, science, and special education). His results indicate that within an apparently homogeneous group characterized by a college major such as education, differences in cognitive styles may exist. No research was found which assessed the cognitive styles of students pursuing technology majors and their specializations. When attempting to utilize cognitive styles research to improve instruction, educators should not assume that, within the field of technology, student cognitive styles are the same. Neither should they assume that the cognitive styles of students pursuing different technical specializations, such as electronics and mechanics, are different. Technology teacher preparation programs continue to be arranged around the unit shop model (Clark, 1989). Brown (1993) suggests that technology educators acquire technical knowledge by taking technical courses: (1) exclusively in technology programs designed to prepare educators, (2) derived from
Analysis of Litopenaeus vannamei Transcriptome Using the Next-Generation DNA Sequencing Technique

Background Pacific white shrimp (Litopenaeus vannamei), the major species of farmed shrimps in the world, has been attracting extensive studies, which require more and more genome background knowledge. The now available transcriptome data of L. vannamei are insufficient for research requirements, and have not been adequately assembled and annotated. Methodology/Principal Findings This is the first study that used a next-generation high-throughput DNA sequencing technique, the Solexa/Illumina GA II method, to analyze the transcriptome from whole bodies of L. vannamei larvae. More than 2.4 Gb of raw data were generated, and 109,169 unigenes with a mean length of 396 bp were assembled using the SOAP denovo software. 73,505 unigenes (>200 bp) with good quality sequences were selected and subjected to annotation analysis, among which 37.80% can be matched in NCBI Nr database, 37.3% matched in Swissprot, and 44.1% matched in TrEMBL. Using BLAST and BLAST2Go softwares, 11,153 unigenes were classified into 25 Clusters of Orthologous Groups of proteins (COG) categories, 8171 unigenes were assigned into 51 Gene ontology (GO) functional groups, and 18,154 unigenes were divided into 220 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. To primarily verify part of the results of assembly and annotations, 12 assembled unigenes that are homologous to many embryo development-related genes were chosen and subjected to RT-PCR for electrophoresis and Sanger sequencing analyses, and to real-time PCR for expression profile analyses during embryo development. Conclusions/Significance The L. vannamei transcriptome analyzed using the next-generation sequencing technique enriches the information of L. vannamei genes, which will facilitate our understanding of the genome background of crustaceans, and promote the studies on L. vannamei.
Prevalence of adverse events in the hospitals of five Latin American countries: results of the ‘Iberoamerican study of adverse events’ (IBEAS)

Background Interest in patient safety (PS) is growing exponentially, fuelled by epidemiological research unveiling the extent of unsafe care. However, there is little information about the frequency of harm in developing and transitional countries. To address this issue, the authors performed a study known as the Iberoamerican Adverse Event Study, through a collaborative between the governments of Argentina, Colombia, Costa Rica, Mexico and Peru, the Spanish Ministry of Health, Social Policy and Equality, the Pan American Health Organization and the WHO Patient Safety. Methods The study used a cross-sectional design, involving 58 hospitals in the five Latin American countries, to measure the point prevalence of patients presenting an adverse event (AE) on the day of observation. All inpatients at the time of the study were included. Results A total of 11 379 inpatients were surveyed. Of these, 1191 had at least one AE that the reviewer judged to be related to the care received rather than to the underlying conditions. The estimated point prevalence rate was 10.5% (95% CI 9.91 to 11.04), with more than 28% of AE causing disability and another 6% associated with the death of the patient. Almost 60% of AE were considered preventable. Conclusions The high rate of prevalent AE found suggests that PS may represent an important public-health issue in the participating hospitals. While new studies may be needed to confirm these results, these may already be useful to inspire new PS-improvement policies in those settings.
Tehrani People’s Attitudes Toward Accented Persian: Impact of Gender, Age, and Education Level

ABSTRACT As Cargile and Giles (1998) state, hearers of distinct accents might be subject to reaction to both linguistic and paralinguistic characteristics of their accented speech, which might give rise to positive/negative attitudes. This study examined Tehrani people‘s attitudes toward four varieties of Persian accented speech. The sample consisted of 188 informants, born and raised in Tehran; 84 were male and 104 female; also, 106 participants were in the age-range of 18-30, 60 in 31-45, and 22 in 45-65. 31 had a high-school diploma, 84 either had a BA degree or were studying toward one, and finally, 73 either had a graduate degree or were studying toward one. The informants completed a questionnaire, on which they evaluated five varieties: Tehrani, Azeri, Isfahani, and Gilaki. Each variety was evaluated on 10 scales: social status, education level, friendliness, generosity, trustworthiness, intelligence, selflessness, perseverance, art appreciation, and ethnic pride, on a Likert scale of 1-6, coupled with “please explain” sections. The individual items were the factor-analyzed, thus falling under three main factors of status, solidarity, and ethnic pride. Analysis of the data revealed a number of significant differences across the 3 factor groups for each variety. Additionally, the varieties differed significantly from each other on individual factor groups. Post-hoc analysis also revealed the impact of gender, age, education level on the ratings. Finally, the coding of open-ended answers identified personal experience, societal stereotyping, ethnically diverse friends, ethnic jokes, and ethnically associated jobs as the underlying reasons for the respective ratings.