gebhart/patrepeval huggingface dataset:
Stepwise‐Graded Si <sub>3</sub> N <sub>4</sub> –SiC Ceramics with Improved Wear Properties (2002)

The processing of stepwise graded Si 3 N 4 /SiC ceramics by pressureless co‐sintering is described. Here, SiC (high elastic modulus, high thermal expansion coefficient) forms the substrate and Si 3 N 4 (low elastic modulus, low thermal expansion coefficient) forms the top contact surface, with a stepwise gradient in composition existing between the two over a depth of ∼1.7 mm. The resulting Si 3 N 4 contact surface is fine‐grained and dense, and it contains only 2 vol% yttrium aluminum garnet (YAG) additive. This graded ceramic shows resistance to cone‐crack formation under Hertzian indentation, which is attributed to a combined effect of the elastic‐modulus gradient and the compressive thermal‐expansion‐mismatch residual stress present at the contact surface. The presence of the residual stress is corroborated and quantified using Vickers indentation tests. The graded ceramic also possesses wear properties that are significantly improved compared with dense, monolithic Si 3 N 4 containing 2 vol% YAG additive. The improved wear resistance is attributed solely to the large compressive stress present at the contact surface. A modification of the simple wear model by Lawn and co‐workers is used to rationalize the wear results. Results from this work clearly show that the introduction of surface compressive residual stresses can significantly improve the wear resistance of polycrystalline ceramics, which may have important implications for the design of contact‐damage‐resistant ceramics.
Impaired interferon production and natural killer cell activation in patients with the skin cancer-prone disorder, xeroderma pigmentosum. (1993)

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder with sun sensitivity, markedly increased skin cancer susceptibility, and defective DNA repair without consistently identified symptoms of immune deficiency. We examined natural killer (NK) cell activity and interferon production in peripheral blood lymphocytes (PBL) of eight XP patients who had multiple primary skin cancers. The XP patients had normal numbers of T cells and NK cells, as well as normal lymphokine-activated killer cell activity and normal tumor necrosis factor-alpha production. Unstimulated NK cell function was 40% of normal controls in five XP patients, but was normal in three other XP patients. However, PBL from all the XP patients tested showed no enhancement of NK activity by the interferon inducer, polyinosinic acid:polycytidilic acid (polyIC) but enhancement by interferon-alpha was normal, suggesting an impairment in interferon production. Parallel studies in non-XP skin cancer patients revealed that both unstimulated and polyIC-enhanced NK activity were normal. Further investigation using PBL from XP patients revealed that the production of interferon-gamma after stimulation with interferon inducers (polyIC, interleukin 2, or K562 tumor cells) was 13-43% of normals. These data indicate that XP lymphocytes have a defect in production of interferons and suggest that defective interferon production, as well as DNA repair defects, may play an important role in the susceptibility of XP patients to skin cancer.
VEHICLE SPEED CONTROL USING ROAD BUMPS (2004)

Road bumps play a crucial role in enforcing speed limits, thereby preventing overspeeding of vehicles. It significantly contributes to the overall road safety objective through the prevention of accidents that lead to deaths of pedestrians and damage of vehicles. Despite the importance of road bumps, very little research has been done to investigate into their design. While documentation exists on quantitative descriptions of road bumps, they offer little guidance to decision making. This work presents a unique approach to solving road bumps design problems. The results of our study reveal three important road bumps variables that influence the control of vehicle speeds. The key variables are bump height, bump width, and effective distance between two consecutive road bumps. Since vehicle speed control is the ultimate aim of this study the relationship between vehicle speed and other variables earlier mentioned is established. Vehicle speed is defined as the product of frequency at which a vehicle is moving over road bumps and the sum of effective distance between two consecutive road bumps. In the determination of bump height we assume a conical shaped curve for analysis as a matter of research strategy. Based on this, two stages of motion were analysed. The first concerns the motion over the bump itself while the second relates to the motion between two consecutive road bumps. Fourier series was then used to formulate a holistic equation that combines these two stages. We used trigonometric functions to model the behaviour of the first stage while with the second stage giving a functional value of zero since no changes in height are observed. We carried out vibration analysis to determine the effect of road bumps on a vehicular system. Arising from this a model component is referred to as an isolation factor. This offers guidance to the safe frequency at which vehicles could travel over road bumps. The work appears to contribute to knowledge in road bump research through the development of a novel approach to the control of vehicle speeds. Significant research progress could be made if engineering and academic communities at large appreciate our viewpoints. With this work it is apparent that varying of the assumptions made in terms of bump shape may produce high proliferation of beneficial research studies. Although this work may reveal a new way of investigation into road bump research, no claim is made for the work comprehensiveness. We expect experts to challenge some of our thoughts and ideas presented in this work.
Thoughts on human-computer interaction in the age of artificial intelligence (2018)

With the rapid development of information technology, the extensive development of artificial intelligence and its successful applications in several industries have given rise to great imaginations of providing computer services to human beings once again. However, as the interface of information communication between humans and computers-human-computer interaction-has not been properly developed, the resulting bottleneck effect has become increasingly evident. The reasons for this can be summarized as follows: (1) lack of learning history of the development experience; and (2) changes in the application scenarios in the age of artificial intelligence result in new demands, which presents a huge challenge to human-computer interaction. This paper presents a review of the history of the development of human-computer interaction, focuses on the core issues of human-computer interaction, and summarizes the important theory of thoughts. Lastly, we present some necessary discussions and reflections on the future development of human-computer interaction.
Electrical transport in crystalline phase change materials (2010)

In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge2Sb2Te5. The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and cyrstalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced (chapter 2.1). Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure (section 2.2.1), kinetics (section 2.2.2), optical properties (section 2.2.3) and electrical properties (section 2.2.4) are discussed. In chapter 2.3 important recent developments such as the identfication of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. Chapter 3 deals with the theoretical background of electrical transport, while chapter 4 introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing, profilometry, ellipsometry, FTIR spectroscopy, van der Pauw, Hall, and phase change optical and electrical switching techniques which are used to obtain the results in chapter 5. The latter chapter is split into two parts. In the first one the material class of doped Sb2Te is investigated with respect to structural, kinetic, optical and electrical properties. The second part covers the study of the systematic variation of the resistivity of pseudo-binary GeTe-Sb2Te3 alloys upon thermal annealing. This variation is discussed in the framework of an insulator to metal transition with the help of results from a combined van der Pauw, XRD, Hall, STM and FTIR study.
Two-dimensional manipulation of micro particles by acoustic radiation pressure in a heptagon cell (2011)

An acoustic particle manipulation system is presented, using a flexible printed circuit board formed into a regular heptagon. It is operated at 4 MHz and has a side dimension of 10 mm. The heptagonal geometry was selected for its asymmetry, which tends to reduce standing wave behavior. This leads to the possibility of having fine control over the acoustic field by varying the output phases of the transducer elements. Configurations with two and three active transducers are demonstrated experimentally. It is shown that with two transducers, the particles align along straight lines, the position of which can be moved by varying the relative excitation phases of the two transducers. With three active transducers, hexagonal-shaped patterns are obtained that can also be moved, again according to the phase of the excitation signals. Huygens' principle-based simulations were used to investigate the resultant pressure distributions. Good agreement was achieved between these simulations and both Schlieren imaging and particle manipulation observations.
Functional Genomic Studies of the Intestinal Response to a Foodborne Enteropathogen in a Humanized Gnotobiotic Mouse Model (2007)

Members of the genus Listeria provide a model for defining host responses to invasive foodborne enteropathogens. Active translocation of Listeria monocytogenes across the gut epithelial barrier is mediated by interaction of bacterial internalin (InlA) and its species-specific host receptor, E-cadherin, whereas translocation across Peyer's patches through M-cells is InlA-independent. To define microbial determinants and molecular correlates of the host response to translocation via these two routes, we colonized germ-free transgenic mice expressing the human enterocyte-associated E-cadherin receptor with wild-type (WT) or mutant L. monocytogenes strains, or its nonpathogenic noninvasive relative Listeria innocua, or with Bacteroides thetaiotaomicron, a prominent gut symbiont. Mouse Gene-Chips, combined with Ingenuity Pathway software, were used to identify canonical signaling pathways that comprise the response to WT L. monocytogenes versus the other species. Gain- and loss-of-function experiments with L. innocua and L. monocytogenes, respectively, demonstrated that the 773-member transcriptional signature of the response to WT L. monocytogenes is largely conserved in the DeltainlA mutant. Internalin-dependent responses include down-regulation of gene networks involved in various aspects of lipid, amino acid, and energy metabolism and up-regulation of immunoinflammatory responses. The host response is markedly attenuated in a listeriolysin-deficient (Deltahly) mutant despite its ability to be translocated to the lamina propria. Together, these studies establish that hly, rather than bacterial invasion of the lamina propria mediated by InlA, is a dominant determinant of the intensity of the host response to L. monocytogenes infection via the oral route.
Conditioning regimens for hematopoietic cell transplantation: one size does not fit all (2014)

An essential component of allogeneic and autologous hematopoietic cell transplantation (HCT) is the conditioning regimen administered before the hematopoietic cell infusion. Early regimens relied on dose intensity, assuming that high-dose chemoradiotherapy would eliminate malignant disease and reinfusion of the graft would then restore hematopoiesis. However, as the contribution of graft-versus-tumor effects to the success of allogeneic HCT was recognized over time, in an effort to exploit these, many investigators lowered the dose of radiation and chemotherapeutic agents in the preparative regimen. This resulted in a major paradigm shift, and consequently, the pool of eligible patients underwent a remarkable expansion. In this article, we provide a review of the definition of high-dose, reduced-intensity, and nonmyeloablative conditioning regimens, the most commonly used agents and combinations, and the evolution of some early regimens. We also provide a brief review of the toxicities associated with these regimens.
Anticipating chaotic synchronization (2000)

Dissipative chaotic systems with a time-delayed feedback can drive near-identical systems in such a way that the driven systems anticipate the drivers by synchronizing with their (arbitrarily distant) future states. This counterintuitive behavior is globally stable, robust, and a pure result of the interplay between delayed feedback and dissipation. Thus it constitutes a rather universal phenomenon of nonlinear dynamics. For small anticipation times, anticipating synchronization also occurs in chaotic systems without a memory term in the driver.
Presynaptic Selectivity of a Ligand for Serotonin 1A Receptors Revealed by In Vivo PET Assays of Rat Brain (2012)

A novel investigational antidepressant with high affinity for the serotonin transporter and the serotonin 1A (5-HT(1A)) receptor, called Wf-516 (structural formula: (2S)-1-[4-(3,4-dichlorophenyl)piperidin-1-yl]-3-[2-(5-methyl-1,3,4-oxadiazol-2-yl)benzo[b]furan-4-yloxy]propan-2-ol monohydrochloride), has been found to exert a rapid therapeutic effect, although the mechanistic basis for this potential advantage remains undetermined. We comparatively investigated the pharmacokinetics and pharmacodynamics of Wf-516 and pindolol by positron emission tomographic (PET) and autoradiographic assays of rat brains in order to elucidate their molecular interactions with presynaptic and postsynaptic 5-HT(1A) receptors. In contrast to the full receptor occupancy by pindolol in PET measurements, the binding of Wf-516 to 5-HT(1A) receptors displayed limited capacity, with relatively high receptor occupancy being achieved in regions predominantly containing presynaptic receptors. This selectivity was further proven by PET scans of neurotoxicant-treated rats deficient in presynaptic 5-HT(1A) receptors. In addition, [(35)S]guanosine 5'-O-[γ-thio]triphosphate autoradiography indicated a partial agonistic ability of Wf-516 for 5-HT(1A) receptors. This finding has lent support to reports that diverse partial agonists for 5-HT(1A) receptors exert high sensitivity for presynaptic components. Thus, the present PET data suggest a relatively high capacity of presynaptic binding sites for partial agonists. Since our in vitro and ex vivo autoradiographies failed to illustrate these distinct features of Wf-516, in vivo PET imaging is considered to be, thus far, the sole method capable of pharmacokinetically demonstrating the unique actions of Wf-516 and similar new-generation antidepressants.
Synthetic Collagen Heterotrimers: Structural Mimics of Wild-Type and Mutant Collagen Type I (2008)

Collagen type I is an AAB heterotrimer assembled from two alpha1 chains and one alpha2 chain. Missense mutations in either of these chains that substitute a glycine residue in the ubiquitous X-Y-Gly repeat with a bulky amino acid leads to osteogenesis imperfecta (OI) of varying severity. These mutations have been studied in the past using collagen-like peptide homotrimers as a model system. However, homotrimers, which by definition will contain glycine mutations in all the three chains, do not accurately mimic the mutations in their native form and result in an exaggerated effect on stability and folding. In this article, we report the design of a novel model system based upon collagen-like heterotrimers that can mimic the glycine mutations present in either the alpha1 or alpha2 chains of type I collagen. This design utilizes an electrostatic recognition motif in three chains that can force the interaction of any three peptides, including AAA (all same), AAB (two same and one different), or ABC (all different) triple helices. Therefore, the component peptides can be designed in such a way that glycine mutations are present in zero, one, two, or all three chains of the triple helix. With this design, we for the first time report collagen mutants containing one or two glycine substitutions with structures relevant to native forms of OI. Furthermore, we demonstrate the difference in thermal stability and refolding half-life times between triple helices that vary only in the frequency of glycine mutations at a particular position.
Syntheses of the two epimeric 5′-methylcytidines, their 5′-phosphates and [5-<sup>3</sup>H]-5′-pyrophosphates, and the two 5′-methyldeoxycytidines. A novel cystosine anhydro-nucleoside with two oxygen bridges between the base and the sugar (1982)

In a series of experiments the starting materials were methyl 2,3-O-isopropylidene-β-D-alto- and -α-L-talofuranosides. These were converted in two steps into the corresponding 2,3,5-tri-O-benzoyl esters, (5) and (11), which were coupled with N-acetylbis(trimethylsilyl)cytosine in the presence of tin(IV) chloride, to the protected nucleosides (19) and (20). Alkaline methanolysis gave the free cytidine homologues, 1-(6-deoxy-β-D-alto- and -α-L-talo-furanosyl)cytosine (23) and (28), which were converted into the crystalline 5′-phosphates (24) and (29), and hence to the dilithium salts of the 5′-pyrophosphates, (25) and (30), by standard procedures. These were labelled at C-5 by bromination, followed by catalytic reduction in tritium gas. The same methyl furanoside starting materials were converted into the 3,5-dibenzoates, (3) and (9), by deacetalation followed by monobenzoylation by the stannylene procedure. Substitution of iodine via the 2-trifluoromethanesulphonates gave iodides which were reduced by tributylstannane to methyl 3,5-di-O-benzoyl-2,6-dideoxy-β-D-ribo- and -α-L-lyxo-hexofuranosides (7) and (13). Coupling of these in the same way as above, followed by alkaline methanolysis, gave the two deoxycytidine homologues, 1-(2,6-dideoxy-β-D-ribo- and -α-L-lyxo-hexofuranosyl)cytosine, (16) and (17), together with their anomers (14) and (15). In another approach to these nucleosides, 4-N-acetyl-2′,3′-O-isopropylidenecytidine was oxidized to the aldehyde (33) which was condensed with dimethylsuiphoxonium methylide to a mixture of epoxides (34) and (35). Hydrogen bromide opening, followed by tributylstannane reduction, converted these epoxides into 4-N-acetyl-1-(2,3-O-isopropylidene-6-deoxy-β-D-allo- and -α-L-talo-furanosyl)cytosine (36) and (37). Treatment of the same mixture dissolved in tetrahydrofuran (THF) by boron trifluorideether gave 4-acetamido-1-(2,5′; 2,6′-dianhydro-2′,3′-O-isopropylidene-α-L-talofuranosyl)-2H-pyrimidine (39), the first reported anhydro-nucleoside with two oxygen bridges between the base and the sugar, available in 18% overall yield from protected cytidine.
A Progressive Approach to the Education of Teachers: Some Principles from Bank Street College of Education (2017)

In this paper we present Bank Street’s approach as represented in a set of five inter-related principles. We begin by briefly describing the origins and rationale of teacher education at Bank Street. From this description we generate principles that emerge from Bank Street’s history and practice, linking each principle to classroom images of teaching and learning. Enactment of these principles can and must vary in response to changing circumstances, needs, and mandates. In our view, this necessary variation highlights the guiding function of an explicit set of principles to govern and ensure the consonance, validity, and legitimacy of new practices.
Secure Motion Verification using the Doppler Effect (2016)

Future transportation systems highly rely on the integrity of spatial information provided by their means of transportation such as vehicles and planes. In critical applications (e.g. collision avoidance), tampering with this data can result in life-threatening situations. It is therefore essential for the safety of these systems to securely verify this information. While there is a considerable body of work on the secure verification of locations, movement of nodes has only received little attention in the literature. This paper proposes a new method to securely verify spatial movement of a mobile sender in all dimensions, i.e., position, speed, and direction. Our scheme uses Doppler shift measurements from different locations to verify a prover's motion. We provide formal proof for the security of the scheme and demonstrate its applicability to air traffic communications. Our results indicate that it is possible to reliably verify the motion of aircraft in currently operational systems with an equal error rate of zero.