gebhart/patrepeval huggingface dataset:
On Predicting the Impact of Resource Redistributions in Streaming Applications (2014)

We propose a method for black-box performance modelling of executions of data-parallel array operations on shared memory multi-core systems. Black-box performance modelling refers to the idea that the source code as well as its attendant compilation process are completely independent from the modelling itself. The performance model exclusively builds on observable behaviour available when executing the compiled code. From given input characteristics and previous runtime observations we predict overall runtimes in relation to the number of cores that can be exclusively used for the task. We show that using our technique our model's runtime predictions fall within 10% of the observed runtime.
Performance evaluation of the MPE-iFEC Sliding RS Encoding for DVB-H streaming services (2008)

This article studies the performance of the Sliding RS Encoding (SRSE) in the transmission of streaming services in DVB-H (Digital Video Broadcasting - Transmission System for Handheld Terminals) networks. The SRSE forms part of a set of specifications called MPE-iFEC which has been recently defined in the DVB-SH (Digital Video Broadcasting - Satellite Services to Handheld Devices) standard and is fully compatible with the link layer of DVB-H. MPE-iFEC is capable of encoding information related to different datagram bursts in a jointly manner in order to counteract the long signal blockages expected in satellite reception. This is what is usually referred to as Multi-Burst Encoding (MBE) and provides a protection that extends across several time sliced bursts. MBE can also improve the reception in terrestrial networks such as DVB-H, which relay in the use of MPE-FEC (Multi Protocol Encapsulation - Forward Error Correction) for link layer protection. The SRSE employs the same Reed Solomon (RS) algorithm used in MPE-FEC and a sliding encoding mechanism in order to perform MBE. This paper evaluates the improvements that the use of SRSE can achieve over the legacy MPE-FEC using vehicular urban field measurements in a DVB-H single frequency network. The effect of the different parameters that regulate the operation of the SRSE will be evaluated and the best configurations for its use in DVB-H will be highlighted.
Building the future of WaferSat spacecraft for relativistic spacecraft (2016)

Recently, there has been a dramatic change in the way space missions are viewed. Large spacecraft with massive propellant-filled launch stages have dominated the space industry since the 1960’s, but low-mass CubeSats and low-cost rockets have enabled a new approach to space exploration. In recent work, we have built upon the idea of extremely low mass (sub 1 kg), propellant-less spacecraft that are accelerated by photon propulsion from dedicated directed-energy facilities. Advanced photonics on a chip with hybridized electronics can be used to implement a laser-based communication system on board a sub 1U spacecraft that we call a WaferSat. WaferSat spacecraft are equipped with reflective sails suitable for propulsion by directed-energy beams. This low-mass spacecraft design does not require onboard propellant, creating significant new opportunities for deep space exploration at a very low cost. In this paper, we describe the design of a prototype WaferSat spacecraft, constructed on a printed circuit board. The prototype is envisioned as a step toward a design that could be launched on an early mission into Low Earth Orbit (LEO), as a key milestone in the roadmap to interstellar flight. In addition to laser communication, the WaferSat prototype includes subsystems for power source, attitude control, digital image acquisition, and inter-system communications.
Caloric restriction improves memory in elderly humans (2009)

Animal studies suggest that diets low in calories and rich in unsaturated fatty acids (UFA) are beneficial for cognitive function in age. Here, we tested in a prospective interventional design whether the same effects can be induced in humans. Fifty healthy, normal- to overweight elderly subjects (29 females, mean age 60.5 years, mean body mass index 28 kg/m(2)) were stratified into 3 groups: (i) caloric restriction (30% reduction), (ii) relative increased intake of UFAs (20% increase, unchanged total fat), and (iii) control. Before and after 3 months of intervention, memory performance was assessed under standardized conditions. We found a significant increase in verbal memory scores after caloric restriction (mean increase 20%; P < 0.001), which was correlated with decreases in fasting plasma levels of insulin and high sensitive C-reactive protein, most pronounced in subjects with best adherence to the diet (all r values < -0.8; all P values <0.05). Levels of brain-derived neurotrophic factor remained unchanged. No significant memory changes were observed in the other 2 groups. This interventional trial demonstrates beneficial effects of caloric restriction on memory performance in healthy elderly subjects. Mechanisms underlying this improvement might include higher synaptic plasticity and stimulation of neurofacilitatory pathways in the brain because of improved insulin sensitivity and reduced inflammatory activity. Our study may help to generate novel prevention strategies to maintain cognitive functions into old age.
Synthesis and Reactions of Pyrazolo[1,5-a]pyridines and Related Heterocycles (2011)

Pyrazolo[1,5-a]pyridines have become subject to growing interest by both synthetic and medicinal chemists, and as such new and simple methods for their synthesis are becoming increasingly more important. They exhibit reactivity which permits substitution at various positions, allowing many diverse chemical structures to be made. This review briefly discusses the medicinal uses of pyrazolo[1,5-a]pyridines, it outlines the synthetic methods which have been used to make them and discusses the chemistries which have been carried out to further functionalise the ring system. Keywords: pyrazolo[1,5-a]pyridine, SYNTHESIS, Pyrazole Ring Formation, Carbon-Nitrogen Bond Formation, Nitrogen-Nitrogen Bond Formation, Carbon-Carbon Bond Formation, Pyridine Ring Formation, Halogenation, Alkylation, Nitrosation, Nitration, Nucleophilic Substitution, Deprotonation, Palladium-Catalysed Reactions, quinolines
Therapeutic Interventions for Increasing Ankle Dorsiflexion After Ankle Sprain: A Systematic Review (2013)

Static-stretching intervention as a part of standardized care yielded the strongest effects on dorsiflexion after acute ankle sprains. The existing evidence suggests that clinicians need to consider what may be the limiting factor of ankle dorsiflexion to select the most appropriate treatments and interventions. Investigators should examine the relationship between improvements in dorsiflexion and patient progress using measures of patient self-reported functional outcome after therapeutic interventions to determine the most appropriate forms of therapeutic interventions to address ankle-dorsiflexion limitation.
MINERVA: a second-generation museum tour-guide robot (2003)

This paper describes an interactive tour-guide robot, which was successfully exhibited in a Smithsonian museum. During its two weeks of operation, the robot interacted with thousands of people, traversing more than 44 km at speeds of up to 163 cm/sec. Our approach specifically addresses issues such as safe navigation in unmodified and dynamic environments, and short-term human-robot interaction. It uses learning pervasively at all levels of the software architecture.
High-resolution imaging of the dynamic tumor cell–vascular interface in transparent zebrafish (2007)

Cell metastasis is a highly dynamic process that occurs in multiple steps. Understanding this process has been limited by the inability to visualize tumor cell behavior in real time by using animal models. Here, we employ translucent zebrafish and high-resolution confocal microscopy to study how human cancer cells invade in tissues, induce angiogenesis, and interact with newly formed vessels. We use this system to study how the human metastatic gene RhoC promotes the initial steps of metastasis. We find that RhoC expression induces a primitive amoeboid-like cell invasion characterized by the formation of dynamic membrane protrusions and blebs. Surprisingly, these structures penetrate the blood vessel wall exclusively at sites of vascular remodeling and not at regions of existing intact vessels. This process requires tumor cells to secrete VEGF, which induces vascular openings, which in turn, serve as portholes allowing access of RhoC-expressing cells to the blood system. Our results support a model in which the early steps in intravasation and metastasis require two independent events: (i) dynamic regulation of the actin/myosin cytoskeleton within the tumor cell to form protrusive structures and (ii) vascular permeablization and vessel remodeling. The integration of zebrafish transgenic technology with human cancer biology may aid in the development of cancer models that target specific organs, tissues, or cell types within the tumors. Zebrafish could also provide a cost-effective means for the rapid development of therapeutic agents directed at blocking human cancer progression and tumor-induced angiogenesis.
An AAA based service customization framework for public WLANs (2005)

An important aspect of providing ubiquitous coverage is service portability to different access network technologies. Current public WLAN deployments lack enablers for a proper delivery of value added data services to which the user may have subscribed in his home cellular network. The paper addresses some of the challenges associated with delivering such value added data services over public WLANs. It suggests enhancements to the currently deployed public WLAN AAA infrastructure by separating user authentication from service authorization. It further proposes that the user's home network get additional information from the public WLAN operator as part of the initial user authentication. This information can be used by the home network to authorize or customize home network based services delivered to the user. The proposed enhancements would leverage the existing WLAN AAA infrastructure for carrying this information.
The Chloroplast Triggers Developmental Reprogramming When MUTS HOMOLOG1 Is Suppressed in Plants   (2012)

Multicellular eukaryotes demonstrate nongenetic, heritable phenotypic versatility in their adaptation to environmental changes. This inclusive inheritance is composed of interacting epigenetic, maternal, and environmental factors. Yet-unidentified maternal effects can have a pronounced influence on plant phenotypic adaptation to changing environmental conditions. To explore the control of phenotypy in higher plants, we examined the effect of a single plant nuclear gene on the expression and transmission of phenotypic variability in Arabidopsis (Arabidopsis thaliana). MutS HOMOLOG1 (MSH1) is a plant-specific nuclear gene product that functions in both mitochondria and plastids to maintain genome stability. RNA interference suppression of the gene elicits strikingly similar programmed changes in plant growth pattern in six different plant species, changes subsequently heritable independent of the RNA interference transgene. The altered phenotypes reflect multiple pathways that are known to participate in adaptation, including altered phytohormone effects for dwarfed growth and reduced internode elongation, enhanced branching, reduced stomatal density, altered leaf morphology, delayed flowering, and extended juvenility, with conversion to perennial growth pattern in short days. Some of these effects are partially reversed with the application of gibberellic acid. Genetic hemicomplementation experiments show that this phenotypic plasticity derives from changes in chloroplast state. Our results suggest that suppression of MSH1, which occurs under several forms of abiotic stress, triggers a plastidial response process that involves nongenetic inheritance.
Channel probing for opportunistic access with multi-channel sensing (2008)

We consider an opportunistic communication system consisting of multiple independent channels with time-varying states. We formulate the problem of optimal sequential channel selection as a restless multi-armed bandit process, for which a powerful policy-Whittle's index policy-can be implemented based on the indexability of the system. We obtain Whittle's index in closed-form under the average reward criterion, which leads to the direct implementation of Whittle's index policy. To evaluate the performance of Whittle's index policy, we provide simple algorithms to calculate an upper bound of the optimal performance. The tightness of the upper bound and the near-optimal performance of Whittle's index policy are illustrated with simulation examples. When channels are stochastically identical, we show that Whittle's index policy is equivalent to the myopic policy, which has a simple and robust structure. Based on this structure, we establish the approximation factors of the performance of Whittle's index policy. Furthermore, we show that Whittle's index policy is optimal under certain conditions.
Development of a small 6-axis force/moment sensor for robot's fingers (2004)

This paper describes the development of a small 6-axis force/moment sensor for robot's fingers (grippers), which detects forces Fx, Fy and Fz, and moments Mx, My and Mz, simultaneously. In order to safely grasp an unknown object using the robot's fingers, and accurately perceive its position in the fingers, it should measure the force in the gripping direction, the force in the gravity direction and moments in each direction, and perform the force control using the measured forces and moments. Also, it should detect moments Mx (x-direction moment), My and Mz to accurately perceive the position of the object in the fingers. Thus, the robot's fingers should be composed of 6-axis force/moment sensors that can measure forces Fx, Fy and Fz, and moments Mx, My and Mz, simultaneously. It is very important for the 6-axis force/moment sensor for an intelligent robot's fingers to be of small size in its body and in its interference errors. Therefore, the new modelling of a small 6-axis force/moment sensor is needed. In this paper, the small 6-axis force/moment sensor for measuring forces Fx, Fy and Fz, and moments Mx, My and Mz simultaneously was newly modelled using several parallel-plate beams (PPBs), designed and fabricated. A characteristic test of the made sensor was performed, and the result shows that the interference errors of the developed sensor are less than 3.93%. Thus, the developed small 6-axis force/moment sensor can be used for robot's fingers.
Complex interactions between the laminin α4 subunit and integrins regulate endothelial cell behavior <i>in vitro</i> and angiogenesis <i>in vivo</i> (2002)

The alpha4 laminin subunit is a component of the basement membrane of blood vessels where it codistributes with the integrins alphavbeta3, alpha3beta1, and alpha6beta1. An antibody against the G domain (residues 919-1207; G(919-1207)) of the alpha4 laminin subunit inhibits angiogenesis in a mouse-human chimeric model, indicating the functional importance of this domain. Additional support for the latter derives from the ability of recombinant G(919-1207) to support endothelial cell adhesion. In particular, endothelial cell adhesion to G(919-1207) is half-maximal at 1.4 nM, whereas residues 919-1018 and 1016-1207 of the G domain are poor cellular ligands. Function blocking antibodies against integrins alphavbeta3 and beta1 and a combination of antibodies against alpha3 and alpha6 integrin subunits inhibit endothelial cell attachment to G(919-1207). Moreover, both alphavbeta3 and alpha3beta1 integrin bind with high affinity to G(919-1207). Together, our studies demonstrate that the G domain of laminin alpha4 chain is a specific, high affinity ligand for the alphavbeta3 and alpha3beta1 integrin heterodimers and that these integrins, together with alpha6beta1, function cooperatively to mediate endothelial cell-alpha4 laminin interaction and hence blood vessel development. We propose a model based on these data that reconcile apparent discrepancies in the recent literature with regard to the role of the alphavbeta3 integrin in angiogenesis.
IL-21 Can Supplement Suboptimal Lck-Independent MAPK Activation in a STAT-3–Dependent Manner in Human CD8+ T Cells (2012)

Although both MHC class II/CD8α double-knockout and CD8β null mice show a defect in the development of MHC class I-restricted CD8(+) T cells in the thymus, they possess low numbers of high-avidity peripheral CTL with limited clonality and are able to contain acute and chronic infections. These in vivo data suggest that the CD8 coreceptor is not absolutely necessary for the generation of Ag-specific CTL. Lack of CD8 association causes partial TCR signaling because of the absence of CD8/Lck recruitment to the proximity of the MHC/TCR complex, resulting in suboptimal MAPK activation. Therefore, there should exist a signaling mechanism that can supplement partial TCR activation caused by the lack of CD8 association. In this human study, we have shown that CD8-independent stimulation of Ag-specific CTL previously primed in the presence of CD8 coligation, either in vivo or in vitro, induced severely impaired in vitro proliferation. When naive CD8(+) T cells were primed in the absence of CD8 binding and subsequently restimulated in the presence of CD8 coligation, the proliferation of Ag-specific CTL was also severely hampered. However, when CD8-independent T cell priming and restimulation were supplemented with IL-21, Ag-specific CD8(+) CTL expanded in two of six individuals tested. We found that IL-21 rescued partial MAPK activation in a STAT3- but not STAT1-dependent manner. These results suggest that CD8 coligation is critical for the expansion of postthymic peripheral Ag-specific CTL in humans. However, STAT3-mediated IL-21 signaling can supplement partial TCR signaling caused by the lack of CD8 association.
Modeling and control of a quadrotor UAV with tilting propellers (2012)

Standard quadrotor UAVs possess a limited mobility because of their inherent underactuation, i.e., availability of 4 independent control inputs (the 4 propeller spinning velocities) vs. the 6 dofs parameterizing the quadrotor position/ orientation in space. As a consequence, the quadrotor pose cannot track an arbitrary trajectory over time (e.g., it can hover on the spot only when horizontal). In this paper, we propose a novel actuation concept in which the quadrotor propellers are allowed to tilt about their axes w.r.t. the main quadrotor body. This introduces an additional set of 4 control inputs which provides full actuation to the quadrotor position/orientation. After deriving the dynamical model of the proposed quadrotor, we formally discuss its controllability properties and propose a nonlinear trajectory tracking controller based on dynamic feedback linearization techniques. The soundness of our approach is validated by means of simulation results.
Fission plasmas and their novel application to power producing nuclear reactors in space (2020)

The specific power (We/kg) requirements for high powered space missions greater than 1MWe present a significant design challenge to the nuclear engineering community. Energy conversion, and the temperature at which it occurs, is central to this problem and remains a limiting factor to realizing high specific power systems. This thesis investigates a static, in-core thermionic energy conversion (TEC) cycle that uses kinetic energy from fission fragments and their resulting high energy beta decay to produce both heat for thermionic emission and ionization of an interelectrode low temperature plasma. This novel plasma ionization scheme allows for dramatically increased device efficiency and loosened design constraints; both are needed for TEC to be competitive with the dynamic Brayton cycle – currently the only technology slated for high powered space missions. We develop an electrical power model, called the Heavy Ion Thermionic Energy Conversion (HITEC) model in order to investigate electrical power characteristics of both single cell and nuclear reactor scale devices in order to assess this reactor’s performance metrics and its applicability to high powered space missions. HITEC was benchmarked against the only existing experimental data set from a de-classified joint research effort [14], and its power characteristics are in good agreement with this experimental data. The reactor scaling portion of HITEC was used to calculate the electrical performance of a 2.5MWth nuclear reactor. Four separate cases were tested on a single core design: we found that in three of the four cases, the HITEC reactor exceeded NASA’s specific power limits for the 1-10 MWe power output range (&gt; 60We/kg). When auxiliary power was implemented for additional plasma ionization, the maximum specific power attained was 348 We/kg. This makes HITEC, an attractive static alternative to the dynamic Brayton cycle for power producing nuclear reactors applied to high power mission sets.
Control of Branching Vs. Cross‐Linking in Conventional Free Radical Copolymerization of MMA and EGDMA Using CoBF as a Catalytic Chain Transfer Agent (2005)

Solution copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) by conventional free radical methodology using a cobalt oxime (CoBF) as a catalytic chain transfer agent allows synthesis at high conversion of fully soluble branched poly (methyl methacrylate)s. Using CoBF levels of 8–32 ppm, mole ratios of MMA/EGDMA up to ∼100/10 can be employed in producing branched products without any macrogelation or microgel formation. Higher levels of EGDMA require higher levels of CoBF to inhibit cross‐linking, but the reactions are difficult to control and have poor reproducibility. An 1H NMR analysis confirms the incorporation of EGDMA at a level comparable to that of the comonomer feed and typically 50–70% of these residues are present as branching segments rather than as pendent partially reacted residues. Double detection (DD) and triple detection (TD) size exclusion chromatographs (SEC) have been used to evaluate the molar mass and branching character of the products. Molar mass data from both instruments show good agreement, and products with molar mass distribution curves very similar to those of previous products prepared using dodecanethiol (DDT) as a stoichiometric chain transfer agent can be produced. The maximum level of EGDMA that can be incorporated using CoBF is, however, lower than is the case when DDT is used. The analytical data from the TDSEC instrument allows the slice‐by‐slice generation of intrinsic viscosity (IV) data and corresponding data for the Zimm branching factor, g′, across the molar mass distribution. At a given molar mass of 130,000 g/mol, g′ correlates well with the level of EGDMA used in the polymerization feed, and is consistent with the 1H NMR data showing efficient incorporation of this branching comonomer.