Miracle-dz/UniFAR-FTUs huggingface dataset:
Implementing a Cooperative MAC Protocol for Wireless LANs

In wireless LANs that provide multi-rate support (IEEE 802.11a, 802.11b), stations that experience poor channel quality tend to use low transmission rates to reduce the bit-error-rate (BER) of each transmission. This phenomenon usually leads to a throughput fairness problem between the stations with good channel quality and those without. This fairness problem has been shown to result in throughput degradation for the whole network [8]. The MAC protocol proposed in [5] addresses this issue using an efficient cooperative scheme. Under this scheme, low rate stations are assisted by a high rate station, referred to as helper stations, in its transmissions. With such assistance, the low rate station will be able to transmit data at a higher rate in a two-hop manner using the helper station. We implemented this new protocol in a Linux testbed. This paper describes the assumptions, the implementation process and the challenges we were presented with. We evaluated the protocol using our testbed through experiments. The implementation of the protocol shows that it performs efficiently in supporting TCP applications.
Maximal and Ventilatory Thresholds Cardiorespiratory Responses to Three Water Aerobic Exercises Compared With Treadmill on Land

Abstract Alberton, CL, Pinto, SS, Antunes, AH, Cadore, EL, Finatto, P, Tartaruga, MP, and Kruel, LFM. Maximal and ventilatory thresholds cardiorespiratory responses to three water aerobic exercises compared with treadmill on land. J Strength Cond Res 28(6): 1679–1687, 2014—The purpose of this study was to compare the cardiorespiratory responses of young women to exercise at the first ventilatory threshold (VT1), the second ventilatory threshold (VT2), and at maximum effort (MAX) between maximal incremental tests performed using water aerobic exercises and a treadmill on land (TL). Twenty women (24.0 ± 2.5 years; 163.3 ± 6.7 cm; 60.0 ± 6.7 kg) underwent 4 maximal tests in randomized order, with a 48-hour interval between tests. Three tests involved performing water aerobic exercises (stationary running, frontal kick, and cross-country skiing) and 1 TL. Oxygen uptake (V[Combining Dot Above]O2), ventilation (VE), and heart rate were measured throughout the tests, and their values at the VT1, VT2, and MAX intensities were determined by 3 independent, experienced physiologists. Repeated measures analysis of variance with Bonferroni post hoc tests were used for comparisons between tests (&agr; = 0.05). Heart rate was significantly higher in the TL condition compared with the water aerobic exercises at the VT1 (p = 0.001), VT2 (p < 0.001), and MAX (p < 0.001) intensities. V[Combining Dot Above]O2 and VE had similar values across the 4 protocols at the VT1 intensity, but significantly higher values were observed with TL (V[Combining Dot Above]O2: p < 0.001; VE: p < 0.001) at the VT2 intensity. At the MAX intensity, V[Combining Dot Above]O2 was significantly higher with TL compared with the 3 water aerobic exercises (p < 0.001), whereas no significant differences in VE between the 4 protocols were found. These results suggest that the prescription of water aerobics classes should be based on specific maximal tests for water aerobic exercises. Training intensities could be overestimated if they were based on maximal tests on dry land.
The tumor-suppressive and potential therapeutic functions of miR-34a in epithelial carcinomas

ABSTRACT Introduction: Many RNA species have been identified as important players in the development of chronic diseases including cancer. Certain classes of regulatory RNAs such as microRNAs (miRNAs) have been investigated in such detail that bona fide tumor suppressive and oncogenic miRNAs have been identified. Because of this, there has been a major effort to therapeutically target these small RNAs. One in particular, a liposomal formulation of miR-34a (MRX34), has entered Phase I trials. Areas covered: This review aims to summarize miRNA biology, its regulation within normal versus disease states and how it can be targeted therapeutically, with a particular emphasis on miR-34a. Understanding the complexity of a single miRNA will aid in the development of future RNA-based therapeutics for a broader range of chronic diseases. Expert opinion: The potential of miRNAs to be developed into anti-cancer therapeutics has become an increasingly important area of research. miR-34a is a tumor suppressive miRNA across many tumor types through its ability to inhibit cellular proliferation, invasion and tumor sphere formation. miR-34a also shows promise within certain in vivo solid tumor models. Finally, as miR-34a moves into clinical trials it will be important to determine if it can further sensitize tumors to certain chemotherapeutic agents.
Measuring normal ocular torsion and its variation by fundus photography in children between 5-15 years of age

Cycloposition has been measured by various methods; however, fundus photography is the most reliable method to evaluate the torsion objectively. We did a prospective study to find out the disc foveal angle (DFA) and its variation in children without squint. We included 210 eyes of 105 children between the ages of 5-15 years. DFA was calculated using standard technique after taking a fundus photograph. The cycloplegic refraction was done and compared. The mean age was 10.6 ± 2.5 years. Mean DFA in right eye (RE) was 6.49 ± 3.25° (0-13°) and in left eye (LE) was 5.80 ± 3.29° (0-12°). The difference between the RE and LE was statistically not significant (P=0.131) (mean 1.15 ±1.39°). Mean DFA in emmetropic children was 6.1° ± 3.4° (n=112 eyes). DFA varies widely in children. The difference observed in DFA measurement for eyes with various refractive errors were compared with DFA measurements for emmetropic eyes.
Hierarchical key derivation scheme for group-oriented communication systems

In recent years, the ubiquity of communication networks speeds up the development of wireless network and the internet applications. In addition to the common service provided by the telecommunication enterprise, how to connect some distinct users to form a network which allow them to deal with their own works is a popular topic that many scholars engage in (Eskeland and Oleshchuk, 2007; Sun and Liu, 2007; Tzeng, 2006). When constructing the network, the key management is the most important problem that each system has to solve. There are many key agreement protocols which are non-hierarchical. However, the hierarchy is ubiquitous in our real life. In this paper, we have achieved a verifiable hierarchical key derivation scheme using the elliptic curve cryptography and the bilinear mapping function which can achieve the same security level but use less bit number when comparing to the RSA system.
An Automatic Analytical Procedure for Searching Corresponding Feature Points in a Cadastral Map

SUMMARY In some recent papers Beinat and Crosilla (2003a, 2003b) have illustrated a new direct procedure, based on Procrustes analysis techniques, for the least squares adjustment of digital cadastral map features. The method has been successfully applied to simultaneously fit a series of fiducial point networks (polygons), each one connecting at least three points measured in the field by professional surveyors, strictly preserving their geometrical shape and linking the whole polygon set to a limited number of fixed points. The proposed procedure considers the various partially or totally overlapping measured polygons as unitary component parts of the general network of fiducial cadastral points to be adjusted. Direct and independent similarity transformation models are applied to each polygon – i.e., the so called Procrustes adjustment model – so to minimise a measure of discrepancy among the various polygons. As well as for the fiducial point network, the same technique can also correctly perform the conformal mosaicking of the new surveyed cadastral parcels with those ones obtained by digitisation of the original map, satisfying further possible geometrical constraints of the map entities like alignments, orthogonality and so on. To achieve the conformal parcel mosaicking in the absence of any topological or structural information, a specific procedure is needed to automatically identify the point-to-point correspondences between the various geometric entities to be connected. Several methods to detect possible correspondences between two sets of equal number of unlabeled points have been developed and investigated. Among these, we report the Umeyama's method (1988) developed to compute the permutation that maximises the agreement between two weighted graphs by way of a singular value decomposition of the relative adjacency matrix product. Another original direct solution, based on pure geometric rules, has been implemented and successively described. For the more general problem of detecting a geometric entity entirely contained within a more complex configuration, e.g. a measured parcel belonging to a cadastral map, a "kernel growing" geometric approach has been developed. The method explained in the paper is based on the analysis and segmentation of the adjacency matrices relative to the specific parcel and to the entire map vertex coordinates, and on the computation and validation of transformation parameters performed by Procrustes analysis techniques. In addition to the cadastral cartographic purposes, the procedure seems suitable for a wider range of possible applications, spacing from the Geographic Information Systems to the industrial and civil engineering design.
A simple solution for model comparison in bold imaging: the special case of reward prediction error and reward outcomes

Conventional neuroimaging techniques provide information about condition-related changes of the BOLD (blood-oxygen-level dependent) signal, indicating only where and when the underlying cognitive processes occur. Recently, with the help of a new approach called “model-based” functional neuroimaging (fMRI), researchers are able to visualize changes in the internal variables of a time varying learning process, such as the reward prediction error or the predicted reward value of a conditional stimulus. However, despite being extremely beneficial to the imaging community in understanding the neural correlates of decision variables, a model-based approach to brain imaging data is also methodologically challenging due to the multicollinearity problem in statistical analysis. There are multiple sources of multicollinearity in functional neuroimaging including investigations of closely related variables and/or experimental designs that do not account for this. The source of multicollinearity discussed in this paper occurs due to correlation between different subjective variables that are calculated very close in time. Here, we review methodological approaches to analyzing such data by discussing the special case of separating the reward prediction error signal from reward outcomes.
Selfish Overlay Network Creation and Maintenance

A foundational issue underlying many overlay network applications ranging from routing to peer-to-peer file sharing is that of the network formation, i.e., folding new arrivals into an existing overlay, and rewiring to cope with changing network conditions. Previous work has considered the problem from two perspectives: devising practical heuristics for the case of cooperative peers and performing game-theoretic analysis for the case of selfish peers. In this paper, we unify the aforementioned thrusts by defining and studying the selfish neighbor selection (SNS) game and its application to overlay routing. At the heart of SNS stands the restriction that peers are allowed up to a certain number of neighbors. This makes SNS substantially different from existing network formation games that impose no bounds on peer degrees. Having bounded degrees has important practical consequences as it permits the creation of overlay structures that require O(n) instead of O(n2) link monitoring overhead. We show that a node's “best response” wiring strategy amounts to solving a k -median problem on asymmetric distance. Best-response wirings have substantial practical utility as they permit selfish nodes to reap substantial performance benefits when connecting to overlays of nonselfish nodes. A more intricate consequence is that even nonselfish nodes can benefit from the existence of some selfish nodes since the latter, via their local optimizations, create a highly optimized backbone, upon which even simple heuristic wirings yield good performance. To capitalize on the above properties, we design, build, and deploy EGOIST, an SNS-inspired prototype overlay routing system for PlanetLab. We demonstrate that EGOIST outperforms existing heuristic overlays on a variety of performance metrics, including delay, available bandwidth, and node utilization, while it remains competitive with an optimal but unscalable full-mesh overlay.
Random Multispace Quantization as an Analytic Mechanism for BioHashing of Biometric and Random Identity Inputs

Biometric analysis for identity verification is becoming a widespread reality. Such implementations necessitate large-scale capture and storage of biometric data, which raises serious issues in terms of data privacy and (if such data is compromised) identity theft. These problems stem from the essential permanence of biometric data, which (unlike secret passwords or physical tokens) cannot be refreshed or reissued if compromised. Our previously presented biometric-hash framework prescribes the integration of external (password or token-derived) randomness with user-specific biometrics, resulting in bitstring outputs with security characteristics (i.e., noninvertibility) comparable to cryptographic ciphers or hashes. The resultant BioHashes are hence cancellable, i.e., straightforwardly revoked and reissued (via refreshed password or reissued token) if compromised. BioHashing furthermore enhances recognition effectiveness, which is explained in this paper as arising from the random multispace quantization (RMQ) of biometric and external random inputs
Large‐Scale Expansion of Mammary Epithelial Stem Cell Aggregates in Suspension Bioreactors

Mutations in the pathways regulating mammary epithelial stem cell (MESC) self‐renewal and differentiation are currently hypothesized to result in uncontrolled cell division and, in turn, breast tumor formation. Although research is aggressively being pursued to understand how such pathways result in breast cancer formation, current studies have been greatly limited by MESC scarcity. To address this issue, this study has successfully developed large‐scale expansion protocols for MESC through the subculture of murine mammary epithelial tissue aggregates, called mammospheres, in suspension bioreactors. Growth kinetics of mammospheres cultured in 125 mL suspension bioreactors and T‐flasks were found to be comparable, achieving cell densities of 3.10 × 105 and 2.75 × 105 cells/mL, respectively. This corresponded to a 4‐fold expansion over 8 days. Yields were also found to be strongly affected by liquid shear forces, where high agitation rates reduced overall cell numbers. Bioreactor cultures were scaled up to 1000 mL operating volumes, resulting in the production of 4.21 × 108 total cells (5.6‐fold expansion) from a single passage. Furthermore, intermittent replacement of culture medium with fresh medium dramatically improved maximum cell densities, resulting in an 11‐fold expansion, thereby enabling the generation of stem cells in quantities sufficient for standard biochemical and genetic analyses. After being cultured in suspension bioreactors for several passages, analysis by flow cytometry of Ki‐67 revealed that 85% of the population was composed of proliferating cells. The successful development of expansion protocols for MESC aggregates in suspension bioreactors makes available experimental avenues that were not previously accessible for breast cancer research, thereby facilitating future investigations into elucidating the role of MESCs in breast cancer tumorigenesis.
Integrating demographic and meteorological data in urban ecology: a case study of container‐breeding mosquitoes in temperate Argentina

Cities are unique ecosystems emerging and growing worldwide due to ongoing urbanising trends. The urban–rural gradient is an excellent setting to evaluate the effect of urbanisation on the distribution of species, a matter of public health concern in the case of disease vectors. Despite this, such distributions are affected by other co-occurring variables, mainly meteorological, that may be confounded by the urbanisation gradient due to the urban heat island effect and maritime climatological conditions in the case of coastal cities. To aid in the design of ecological studies within the urban–rural transition zone, a mapping protocol was designed and applied to Buenos Aires City and its surroundings. Based on road density and district-level population counts, a detailed (1 km 2 pixel) urbanisation map was obtained which, combined with a temperature map, rendered a final urbanisation × temperature product with six classes. The resulting zonation was tested by modelling the distribution of the vector mosquitoes Aedes aegypti and Culex pipiens in artificial containers. The selected model explained the occurrence of mosquitoes 59% better than chance as a function of the urbanisation × temperature categories and the natural lighting condition of the container. This novel zonation approach allows partitioning of environmental heterogeneity prior to the selection of study sites to avoid confounding gradients and provides multiple advantages, such as making comparisons across cities easier, extrapolating the results of site-scale experiments and identifying priority areas for control measures.
Indicadores cualitativos para la medición de la calidad en la educación

This research shows the process to design a qualitative indicator system to assess the quality of Curricular Management in schools that are members of the Jesuit School Association of Colombia ( ACODESI – Spanish acronyms), certified under ISO 9000:2000. The qualitative curriculum management was evaluated from a qualitative perspective, based on five parameters that are paramount in assessing curricular management ( relevance, impact, transcendence, systematization, and degree of satisfaction ) and seven curricular components ( principles, criteria, study plan, programs and projects, methodologies, management and guidance ). The following stages were followed to design the indicator system: preparing the conceptual framework, collecting documentary information through surveys and interviews, analyzing information, constructing an indicator system, and approval by expert judges. The study concludes that applying this new system offers a way to assess the quality of the education offered at the member schools of the Association; however, the system also requires a comprehensive look as it is a qualitative instrument that opposes the general trend to quantify results in schools.
Synergid Cell Death in Arabidopsis Is Triggered following Direct Interaction with the Pollen Tube1[W][OA]

During angiosperm reproduction, one of the two synergid cells within the female gametophyte undergoes cell death prior to fertilization. The pollen tube enters the female gametophyte by growing into the synergid cell that undergoes cell death and releases its two sperm cells within the degenerating synergid cytoplasm to effect double fertilization. In Arabidopsis (Arabidopsis thaliana) and many other species, synergid cell death is dependent upon pollination. However, the mechanism by which the pollen tube causes synergid cell death is not understood. As a first step toward understanding this mechanism, we defined the temporal relationship between pollen tube arrival at the female gametophyte and synergid cell death in Arabidopsis. Using confocal laser scanning microscopy, light microscopy, transmission electron microscopy, and real-time observation of these two events in vitro, we demonstrate that synergid cell death initiates after the pollen tube arrives at the female gametophyte but before pollen tube discharge. Our results support a model in which a signaling cascade triggered by pollen tube-synergid cell contact induces synergid cell death in Arabidopsis.
SR‐BI, CD36, and caveolin‐1 contribute positively to cholesterol efflux in hepatic cells

In non‐hepatic cells, scavenger receptor class B type I (SR‐BI), cluster of differentiation 36 (CD36), and caveolin‐1 were described as mediators of cholesterol efflux, the first step of reverse cholesterol transport (RCT). Stable transformants of HepG2 cells overexpressing SR‐BI, CD36, or caveolin‐1 were generated, as well as cells overexpressing both caveolin‐1 and SR‐BI or caveolin‐1 and CD36 in order to address the effect of caveolin‐1 on both receptor activities. These cells were analyzed for their ability to efflux cholesterol to HDL3. Our results show that overexpressing SR‐BI, CD36, or caveolin‐1 increases cholesterol efflux by 106, 92, and 48%, respectively. Moreover, the dual overexpressions of caveolin‐1 and SR‐BI or caveolin‐1 and CD36 lead to a more prominent increase in cholesterol efflux. Studies were also conducted with primary cultures of SR‐BI knockout (KO), CD36 KO, and SR‐BI/CD36 double‐KO (dKO) mice. SR‐BI KO and SR‐BI/CD36 dKO hepatic cells show 41 and 56% less cholesterol efflux, respectively, than normal hepatic cells. No significant difference was observed between the efflux of normal and CD36 KO cells. The difference between the role of human and murine CD36 correlated with the absence of CD36 dimers in mouse caveolae/rafts. Overall, our results show that SR‐BI is clearly involved in cholesterol efflux in mouse and human hepatic cells, while CD36 plays a significant role in human cells. Copyright © 2010 John Wiley & Sons, Ltd.
Meta‐analysis of rate ratios with differential follow‐up by treatment arm: inferring comparative effectiveness of medical devices

Modeling events requires accounting for differential follow‐up duration, especially when combining randomized and observational studies. Although events occur at any point over a follow‐up period and censoring occurs throughout, most applied researchers use odds ratios as association measures, assuming follow‐up duration is similar across treatment groups. We derive the bias of the rate ratio when incorrectly assuming equal follow‐up duration in the single study binary treatment setting. Simulations illustrate bias, efficiency, and coverage and demonstrate that bias and coverage worsen rapidly as the ratio of follow‐up duration between arms moves away from one. Combining study rate ratios with hierarchical Poisson regression models, we examine bias and coverage for the overall rate ratio via simulation in three cases: when average arm‐specific follow‐up duration is available for all studies, some studies, and no study. In the null case, bias and coverage are poor when the study average follow‐up is used and improve even if some arm‐specific follow‐up information is available. As the rate ratio gets further from the null, bias and coverage remain poor. We investigate the effectiveness of cardiac resynchronization therapy devices compared with those with cardioverter‐defibrillator capacity where three of eight studies report arm‐specific follow‐up duration. Copyright © 2015 John Wiley & Sons, Ltd.