cssi/SciSciGPT-SciSciNet huggingface dataset:
Radiation tolerance of a dual-band IR detector based on a pBp architecture

Infrared (IR) detectors operated in the space environment are required to have high performance while being subjected to a variety of radiation effects. Sources of radiation in space include the trapped particles in the Van Allen belts and transient events such as solar events and galactic cosmic rays. Mercury cadmium telluride (MCT)-based IR detectors are often used in space applications because they have high performance and are generally relatively tolerant of the space environment when passivated with CdTe; often, the readout-integrated circuit is far more susceptible to radiation effects than the detector materials themselves. However, inherent manufacturing issues with the growth of MCT have led to interest in alternative detector technologies including type-II strained-layer superlattice (T2SLS) infrared detectors with unipolar barriers. Much less is known about the radiation tolerance properties of these SLS-based detectors compared to MCT. Here, the effects of 63 MeV protons on variable area, single element, dual-band InAs/GaSb SLS detectors in the pBp architecture are considered. When semiconductors devices are irradiated with protons with energies of 63 MeV the protons are capable of displacing atoms within their crystalline lattice. The SLS detectors tested here utilize a pBp architecture, which takes advantage of the higher mobility electrons as the minority photocarrier. These detectors are also dual-band, implying two absorbing regions are present and separated by the unipolar barrier. The absorbers have cutoff wavelengths of roughly 5 and 9 μm allowing for mid-wave (MWIR) and long-wave (LWIR) infrared detection, respectively. The radiation effects on these detectors are characterized by dark current and quantum efficiency as a function of total ionizing dose (TID) or, equivalently, the incident proton fluence.
A study of the contacts of a diffused resistor

Abstract The total resistance of a diffused resistor can be expressed in terms of bulk sheet resistance and three correction terms—namely, contact resistance, current crowding resistance in the contact region, and the contact width correction. The latter two terms have been arrived at theoretically. A new test structure has been designed to measure the metal-silicon contact sheet resistivity and the contact resistance of the resistor. The maximum current density in the contact region is also determined experimentally.
SINCE BENNINGTON: EVIDENCE OF CHANGE IN STUDENT POLITICAL BEHAVIOR

In contrast to students in other countries American college students seem politically apathetic. Yet their college experience does influence their attitudes and a sequence of studies has attempted to determine how much they change and in what ways. Alex S. Edelstein is Associate Professor in the School of Communications at the University of Washington. This article is based on a paper he presented to the Annual Conference of the American Association for Public Opinion Research in May 1962.
Writing Treatment for Aphasia: A Texting Approach

Purpose Treatment studies have documented the therapeutic and functional value of lexical writing treatment for individuals with severe aphasia. The purpose of this study was to determine whether s...
Ductile tearing instability in some engineering thermoplastic blends

The stability of ductile crack growth in two engineering thermoplastic blends is examined. The blends are a poly(phenylene oxide)/nylon 6,6 blend and a poly(butylene terephthalate)/polycarbonate blend. Fracture tests were performed with single-edge notched specimens in tension and three-point bending over a wide range of test speeds. Both larger radius notches and longer specimens were found to promote ductile tearing instability. This behavior is attributed to the higher driving force for crack growth produced by increased elastic energy storage before crack initiation. Over a certain range of test speeds, these factors lead to a novel effect of notch sharpness on toughness; a sharp notch gives rise to a higher fracture energy than does a blunt notch. The results are discussed in terms of the tearing modulus concept developed by Paris and co-workers.
PARALLEL NEUROSYS: A system for the simulation of very large networks of biologically accurate neurons on parallel computers

Abstract We present a software package for the simulation of very large neuronal networks on parallel computers. The package can be run on any system with an implementation of the Message Passing Interface standard. We also present some example results for a simple neuronal model in networks of up to a quarter of a million neurons. The full software package as well as usage and installation guidelines can be found in [http://cs.usfca.edu/neurosys].
Large-Scale Metabolomics Reveals a Complex Response of Aspergillus nidulans to Epigenetic Perturbation

The microbial world offers a rich source of bioactive compounds for those able to sift through it. Technologies capable of quantitatively detecting natural products while simultaneously identifying known compounds would expedite the search for new pharmaceutical leads. Prior efforts have targeted histone deacetylases in fungi to globally activate the production of new secondary metabolites, yet no study has directly assessed its effects with minimal bias at the metabolomic level. Using untargeted metabolomics, we monitored changes in >1000 small molecules secreted from the model fungus, Aspergillus nidulans, following genetic or chemical reductions in histone deacetylase activity (HDACi). Through quantitative, differential analyses, we found that nearly equal numbers of compounds were up- and down-regulated by >100 fold. We detected products from both known and unknown biosynthetic pathways and discovered that A. nidulans is capable of producing fellutamides, proteasome inhibitors whose expression was induced by ∼100 fold or greater upon HDACi. This work adds momentum to an "omics"-driven resurgence in natural products research, where direct detection replaces bioactivity as the primary screen for new pharmacophores.
Designer emission spectra through tailored energy transfer in nanoparticle-doped silica preforms

This Letter provides a qualitative proof of concept for purposefully tailoring the emission spectrum of glass by spatially localizing dissimilar dopants to control the degree of energy transfer. More specifically, modified-chemical-vapor-deposition-derived silica preforms were solution doped with either a solution of individually Eu3+- or Tb3+-doped nanoparticles or a solution of Eu3+/Tb3+-codoped nanoparticles. The preform prepared using the codoped nanoparticles exhibited energy transfer from the Tb3+ to the Eu3+ ions, whereas the preform containing individually doped nanoparticles yielded only discretely Tb3+ or Eu3+ emissions. The extension of this work to broadband amplifiers and lasers is discussed.
Design of emulsion chambers for cosmic ray experiments at balloon altitudes

Abstract Emulsion chambers are effective detectors for the study of cosmic ray composition and interactions at balloon altitudes. Important design considerations are discussed and examples of actual chambers are described.
The sedimentation history of Lake Huron and Georgian Bay: results from analysis of seismic reflection profiles

An extensive seismic reflection profile survey conducted concurrently with a sediment coring program in northern Lake Huron, Georgian Bay, and the North Channel revealed a detailed Holocene lake level history. Seven acoustic sequences were identified in the seismic stratigraphy, and these sequences show great variation in both the character and the spatial distribution of sediment deposition through time. The depths to the acoustically-defined sequence boundaries were digitized from the analog seismic records and merged with Loran-C navigation records from the cruise, yielding a three-dimensional record of the location of each sequence boundary. Thicknesses of the sequences were calculated from these depths, and a minimum-curvature spline surface was fit to the thickness data. These surfaces were used to construct isopach maps which show the trends in thickness of sediment accumulation throughout the lake basins for each of the sequences.
Tissue-level transport mechanisms of intraperitoneally-administered monoclonal antibodies

Monoclonal antibodies (MAbs), produced for specific tumor antigens, can be linked with radioisotopes or metabolic toxins and administered intraperitoneally (i.p.) to treat metastatic cancer located on the peritoneum. Despite their specific binding properties, these proteins distribute to the serosal surface of all tissues surrounding the cavity in the same manner as other serum proteins. Recent data have raised a problem of access of the solution containing the MAb to significant portions of the peritoneal surface. If the MAb does arrive at the surface of the tumor, it penetrates via diffusion and convection. The rapidity and depth of penetration of the MAb are very dependent on the binding characteristics of the MAb to the tumor cells. Current data indicate that tumors often have a large interstitial space relative to normal muscle, and this can accelerate both diffusion and convection. However, a highly permeable tumor vasculature in the absence of lymphatic drainage has also been shown to produce interstitial pressure gradients from the center toward the periphery of the tumor, setting up a potential outward flow which may be a significant barrier to the movement of MAbs into the nodule. While theoretical mechanisms of diffusion, convection, and binding are well established, there is still a great need for in vivo data.
Near-threshold fatigue crack growth in 8090 Al-Li alloy

Near-threshold fatigue crack growth was studied in 8090-T8771 Al-Li alloy tested in moist laboratory air. The testing was conducted using (1) the ASTM E-647 load-shedding procedure, (2) a power-law load-shedding procedure, and (3) a constant-amplitude (CA) loading procedure. Crack closure in the three procedures was analyzed. In reconciling fatigue crack growth rates (FCGRs) with different crack closure levels under identical testing parameters, the conventional {Delta}K{sub eff} (=K{sub max} {minus} K{sub op}) fails to correlate the test data and the modified {Delta}K{sub eff} (=K{sub max} {minus} {chi}K{sub op}, where {chi} is the shielding factor, defined by an energy approach) is proven to be the true crack driving force. A parallel slip-rupture model is proposed to describe the mechanism of near-threshold fatigue crack growth in this ally. The model explains the mode transition from crystallographic slip band cracking (SBC) to subgrain boundary cracking (SGC)/brittle fracture (BF) in terms of microstructure-environment synergy. The transition is related to the material`s short-transverse grain size.
Foresight for a responsible future with ICT

The ACM Code of Ethics asserts that computing professionals have an ethical responsibility to minimize the negative consequences of information and communication technologies (ICT). Negative consequences are rarely intended, but they can often be foreseen with careful sociotechnical analysis in advance of system building. Motivated by an interest in extremely complex sociotechnical contexts (e.g., mortgage lending and automated trading) where ICT appears to be having negative consequences in addition to many benefits, this paper identifies and evaluates future-oriented problem analysis and solution design tools in three potentially relevant literatures: 1) ICT ethics, 2) environmental sustainability, and 3) technology hazards. Several promising future-oriented technology analysis techniques (e.g., anticipatory technology ethics, technology roadmapping, morphological analysis, and control structure analysis) were found and are discussed in this paper, but much work remains to be done to customize them, integrate them, and codify them for use in education and high-quality IS research on very complex sociotechnical contexts like the global financial network.
PSYCHOANALYSIS, ADAPTATION, AND EDUCATION: II. DEVELOPMENT OF THINKING

The development of the capacity for reality testing, whose enhancement has been viewed as a central function of education, presupposes both the capacity to focus attention on external and intra-psychic phenomena and the development of organized thought. Reconsidering traditional psychoanalytic views of these two concepts in terms of more recent formulations, attention is defined in terms of the child's attitude toward reality rather than in terms of the means by which mental contents reach consciousness. The development of thought or secondary process activity is also discussed in terms of an adaptational framework which circumvents assumptions regarding psychic energy and its transformation. These two concepts are discussed in terms of the school's role in fostering the child's mastery of reality.
β-adrenergic receptor signaling pathways mediating cell survival in cardiomyocytes: A role for PKCε inhibition?

The cardiotoxic effects associated with sustained systemic levels of sympathetic catecholamines have been well described, with plasma levels of norepinephrine (NE) inversely correlated with survival in patients with chronic heart failure. Elevated NE levels were originally thought to be a compensatory response designed to maintain adrenergic drive in the face of reduced b-adrenergic receptor (bAR) levels. Within the last 10 years, however, thinking regarding these issues has shifted so that it is the reduction in bAR levels that is now seen as the compensatory response (perhaps to counteract the deleterious effects of circulating NE). This shift in thinking has been reinforced by the remarkable clinical ef®cacy of beta-blocker therapy in the treatment of heart failure as well as by animal studies that indicate that heightened adrenergic drive may play an important role in cardiomyocyte cell death and the progression to heart failure. Studies in isolated ventricular myocytes and in transgenic animals overexpressing bARs indicate that the toxic effects of increased b-adrenergic stimulation are mediated speci®cally through only one of the two predominant b-AR subtypes expressed in the heart, namely b1ARs. The b2ARs do not normally transduce death signals but instead activate signaling cascades that protect cardiomyocytes
Schumpeter and Max Weber — Central Visions and Social Theories

I. Introduction, 373. — II. Central visions, 375. — III. Social theories, 383. — IV. Conclusions, 393.
Applying models of user activity for dynamic power management in wireless devices

In this paper we use a large dataset of wireless user activity traces to test the various dynamic power management schemes. We also present and test our own empirically-driven dynamic power-saving algorithms, which are based on prior observations of user activity patterns. We believe that this sort of analysis can guide adoption of a user-behavior driven approach to radio and communications power management, and, in networking-centric devices, power management for the entire device. Additionally, understanding the characteristics of user-activity and efficient mechanisms to predict this activity can help inform the design of power-saving schemes for future networking protocols.
Non-aqueous solvents in anion-exchange separations

Abstract Distribution coefficients are measured for the partition of metal ions between anionexchange resin and organic solvent-water mixtures containing hydrochloric acid. The presence of an organic solvent causes metal ions to be taken up at lower hydrochloric acid concentrations. In many cases, distribution coefficients are significantly higher than in water-hydrochloric acid systems. If other conditions are comparable, the order of distribution coefficients in alcohol-water-hydrochloric acid is: isopropyl > ethyl > methyl alcohol. Column separations of metal ion mixtures can be carried out by eluting with alcohol-water-hydrochloric acid mixtures of different compositions. Successful separations of a number of mixtures are reported.
Correctness and composition of software architectures

The design of a large system typically involves the development of a hierarchy of different but related architectures. A criterion for the relative correctness of an architecture is presented, and conditions for architecture composition are defined which ensure that the correctness of a composite architecture follows from the correctness of its parts. Both the criterion and the composition requirements reflect special considerations from the domain of software architecture.The main points are illustrated by means of familiar architecture for a compiler. A proof of the relative correctness of two different compiler architectures shows how to decompose a proof into generic properties, which are proved once for every pair of architectural styles, and instance-level properties, which must be proved for every architecture.
BJT&#8212;MOSFET transconductance comparisons

Through normalization it becomes possible to construct curves of considerable generality for comparing the transconductance properties of BJT's and MOSFET's. Three comparisons are given. The first presents transconductance as a function of output current; the second, transconductance divided by output current as a function of input voltage; and the third, transconductance as a function of input voltage. The BJT advantage increases rapidly with output current and (or) input voltage. The curves approach each other under extremely low-level conditions, but appreciable deviations from the simple theory upon which the present analysis is based also occur in the low-level regime--especially deviations connected with subthreshold conduction in the MOSFET, as well as "excess" conduction near but above threshold. For these reasons, the moderate-level portions of the simple-theory comparisons are the most meaningful. Recently developed subthreshold analysis is also used in the second comparison.
Time-resolved CH (A 2 Δ and B 2 ∑ − ) laser-induced fluorescence in low pressure hydrocarbon flames

Total collisional removal rate constants for the CH A2Δ and B2∑− electronic states are obtained in low pressure (<20-Torr) hydrocarbon flames. The B state is consistently removed ~70% faster than the A state. Variations of ±50% are observed for different rotational levels and positions in the flame. For these flames, A-state emission following excitation of the B state indicates a rapid electronic-to-electronic energy transfer pathway that is insensitive to collision environment. Upper limits to the collider specific cross sections are obtained for H2O, N2, and CO2. The CH concentration and temperature profiles are measured and parametrized using a unique method.
Arginine/Serine-Rich Domains of SR Proteins Can Function as Activators of Pre-mRNA Splicing

Serine/arginine (SR)-rich splicing factors contain an RNA binding domain and an arginine/serine (RS)-rich domain required for protein-protein interactions. In addition to their roles in the basic splicing reaction, SR proteins function as components of splicing enhancer complexes. Here, we investigate the role of RS domains in splicing enhancer function. Hybrid proteins containing RS domains fused to the MS2 RNA binding protein were tested in vitro with RNA substrates bearing an MS2 recognition sequence. These hybrid proteins activated splicing in nuclear extracts, but not in S100 extracts lacking SR proteins. However, intact recombinant SR proteins could complement the activity of the hybrid proteins in S100 extracts. These data demonstrate that RS domains function as splicing activators and suggest that the general and enhancer-dependent functions of SR proteins can be uncoupled.
Adrenocortical hormone regulation of nicotine sensitivity in mice.

Abstract The possibility that nicotine-induced corticosterone (CCS) release regulates nicotine sensitivity was investigated in female mice of the C3H strain. Adrenalectomy (ADX) resulted in an increase in nicotine sensitivity as measured in a number of physiological and behavioral tests. In ADX animals, chronic CCS (100 μg/ml) administered in the drinking solution normalized nicotine sensitivity. Dexamethasone (DEX), a potent synthetic glucocorticoid which interacts with a distinct population of CNS steroid receptors, did not reverse the effects of ADX. Unoperated animals administered CCS (200 μg/ml) were protected from the effects of nicotine for several test battery parameters. ADX had no effect on the number of brain nicotinic cholinergic receptors and also did not alter nicotine metabolism. These data support the hypothesis that CCS secretion modulates nicotine sensitivity in the mouse; however, the mechanisms by which this regulation occurs are unknown.
Northern Corn Rootworm (Coleoptera: Chrysomelidae) Temperature Requirements for Egg Development

Temperature-dependent development of laboratory-wintered eggs of northern corn rootworm, Diabrotica barberi Smith & Lawrence, was described using data from constant temperature laboratory experiments. Median development of postdiapause eggs at constant temperatures of 15, 18, 20, 23, 25, 27, and 30°C required 59, 30, 24, 17, 15.5, 14, and 14 d, respectively. Linear and nonlinear models were fitted to temperature versus developmental rate data. Variation in developmental rates across temperatures was modeled with a cumulative Weibull distribution. Mean developmental rate was linear between 15 and 27°c, optimal at 27°c, and decreased at 30°C. The thermal threshold for development (10.9°C) was determined by extrapolation with median egg hatch occurring after 238 DD (10.9).
Enhanced leakage-current pulse-induced changes in impatt oscillators

Two types of stables changes in c.w. X-band impatt oscillators have been observed after exposure to pulses of enhanced leakage current. The first change is indicated by a change in r.f. power and frequency while maintaining a `clean? r.f. spectrum, and is attributed to parasitic circuit-induced instabilities (with changes in oscillator characteristics thought to be influenced by changes in harmonic phasing). The second change is indicated by a modulated r.f. spectrum and oscillations in bias voltage after irradiation, and is clearly attributed to bias-circuit oscillations. These conclusions are supported by experimental results with Si and GaAs diodes in a resonant cap waveguide oscillator circuit. Enhanced leakage-current pulses up to 5 mA in amplitude were obtained using 10 MeV electron pulses from a linear accelerator. The r.f. impedance was adjusted by varying the sliding short-circuit position, while the bias-circuit impedance was varied independently by inserting various length cables between an RC bias network and the diode.
Statechart Analysis with Symbolic PathFinder

We report here on our on-going work that addresses the automated analysis and test case generation for software systems modeled using multiple State chart formalisms.
Unstimulated Primary CD4+ T Cells from HIV-1-Positive Elite Suppressors Are Fully Susceptible to HIV-1 Entry and Productive Infection

Elite controllers or suppressors (ES) are a group of HIV-1-infected individuals who maintain viral loads below the limit of detection of commercial assays for many years. The mechanisms responsible for this remarkable control are under intense study, with the hope of developing therapeutic vaccines effective against HIV-1. In this study, we addressed the question of the intrinsic susceptibility of ES CD4+ T cells to infection. While we and others have previously shown that CD4+ T cells from ES can be infected by HIV-1 isolates in vitro, these studies were confounded by exogenous activation and in vitro culture of CD4+ T cells prior to infection. In order to avoid the changes in chemokine receptor expression that have been associated with such exogenous activation, we infected purified CD4+ T cells directly after isolation from the peripheral blood of ES, viremic patients, and uninfected donors. We utilized a green fluorescent protein (GFP)-expressing proviral construct pseudotyped with CCR5-tropic or CXCR4-tropic envelope to compare viral entry using a fluorescence resonance energy transfer-based, single-round virus-cell fusion assay. The frequency of productive infection was also compared by assessing GFP expression. CD4+ T cells from ES were as susceptible as or more susceptible than cells from viremic patients and uninfected donors to HIV-1 entry and productive infection. The results of this physiological study strongly suggest that differences in HIV-1 entry and infection of CD4+ T cells alone cannot explain the elite control of viral replication.
Coloration of glass exposed to atomic oxygen

The atomic oxygen in low earth orbit is harmful to spacecraft materials. Simulation of this space environment is often done with a plasma asher. We observed a browning effect of common glass placed in a plasma asher. After a detailed analysis, we conclude that this browning effect was not due to deposition of a film on the material surface; rather, it was the effect of optical color centers generated by the plasma. Thus ashing experiments can be safely carried out on space materials, without fears of spurious film deposition.
CHANGES IN OXIDATIVE STRESS AND VASCULAR FUNCTION AS DETERMINANTS OF PROGRESSION OF ATHEROSCLEROSIS

Complications of atherosclerosis are the leading cause of morbidity and mortality in the Western world. Progression of atherosclerosis is associated with a greater risk for adverse outcomes. We sought to investigate the determinants of progression of carotid atherosclerosis. Subjects (n= 120, 60±9
The contribution of abiotic processes to buried litter decomposition in the northern Chihuahuan desert.

Creosobebush (Larrea tridentata) fine litter was treated with either the general biocide HgCl2 and CuSO4 or water (controls) and buried 5 cm beneath the soil surface in the northern Chihuahuan Desert. The treated litter showed significantly less mass loss than controls during the three month summer-autumn field study; controls lost about 20% of the original mass while treated litter lost less than 2%. In addition, the total nitrogen content of the control litter increased from an initial concentration of about 14.08 g kg-1 to 17.62 g kg-1 dry weight by the end of the study, while treated litter nitrogen content decreased to 13.30 g kg-1. Results suggest abiotic processes other than leaching have little effect on the decomposition of buried litter in this environment.
A 6.5GHz 54mW 64-bit Parity-Checking Adder for 65nm Fault-Tolerant Microprocessor Execution Cores

This paper describes a parity-checking fault-tolerant adder designed for 6.5 GHz operation with total power consumption of 54 mW, targeted for 65 nm 64-bit microprocessor execution cores. The adder is fully self-checking and guarantees 100% coverage of single-faults (including multi-bit output errors originating from single-faults) on any sequential/combinational node in the design. The sparse-tree design enables partial pre-computation of the critical carry-parities, resulting in 33% reduction in parity-computation delay overhead with a low 6% area overhead for fault-detection.
Alcohol and drug use among sexual minority college students and their heterosexual counterparts: the effects of experiencing and witnessing incivility and hostility on campus

PURPOSE Research suggests that discrimination contributes to increased substance use among sexual minorities. Subtle discrimination and witnessing mistreatment, however, have received little attention. Using minority stress theory as a conceptual framework the authors examined the intersection of sexual orientation, experiencing and witnessing incivility and hostility, and students' alcohol and drug use. The authors hypothesized that experiencing/witnessing incivility/hostility would mediate the relationship between sexual minority status and drinking and drug use, as well as problematic use of these substances. METHODS Data were taken from a campus climate survey (n = 2497; age mean [M] = 23.19 years; 61% female; 17% sexual minorities). Controlling for demographics, logistic regressions depicted specifications for each path of the mediation analysis and bootstrapping was used to assess the significance of each sexual minority-mistreatment-drinking/drug use path. RESULTS Experiencing incivility mediated the relationship between sexual minority status and problematic drinking. Sexual minority college students were more likely to personally experience incivility (adjusted odds ratio [AOR] = 1.87; 95% confidence interval [CI] = 1.51-2.33), which was associated with greater odds of problematic drinking (AOR = 1.64; 95% CI = 1.35-2.00). The mediation path was significant at P < 0.001. Further, witnessing hostility mediated the relationship between sexual minority status and problematic drinking. Sexual minority college students were more likely to witness hostility (AOR = 1.87, 95% CI = 1.48-2.36), which was associated with greater odds of problematic drinking (AOR = 1.53; 95% CI = 1.24-1.90). The mediation path was significant at P < 0.01. CONCLUSION The results provide further evidence for minority stress theory and suggest that clinical alcohol use interventions with sexual minorities need to assess personal incivilities and witnessing interpersonal mistreatment, especially hostility. Campus climate interventions that address subtle discrimination as well as harassment and violence may help reduce problematic drinking.
Varieties of knowledge elicitation techniques

Information on knowledge elicitation methods is widely scattered across the fields of psychology, business management, education, counseling, cognitive science, linguistics, philosophy, knowledge engineering and anthropology. The purpose of this review is to (1) identify knowledge elicitation techniques and the associated bibliographic information, (2) organize the techniques into categories on the basis of methodological similarity, and (3) summarize for each category of techniques strengths, weaknesses, and recommended applications. The review is intended to provide a starting point for those interested in applying or developing knowledge elicitation techniques, as well as for those more generally interested in exploring the scope of the available methodology.
Making Combinatorial Libraries of Titanium Based Alloys by Direct Metal Deposition Technique

α/β type titanium alloys, such as Ti-6Al-4V and Ti-6Al-7Nb, have been used for orthopedic implant materials because of their combination of biocompatibility, corrosion resistance and mechanical properties. However, toxicity of alloying elements is a concern. In this project, it is proposed to design the new type of titanium alloys composed of non-toxic elements, such as Ti, Al, and Fe with lower modulus of elasticity and greater corrosion resistance. To find the optimal ratio of components in the Ti-Al-Fe system is important. The composition of the alloy determines its properties. Using combinatorial approach the optimal ratio can be found relatively easily. Direct metal deposition (DMD) is a novel precise manufacturing process for fabricating metal parts directly from Computer Aided Design (CAD) solid models. The DMD process allows making several layers of different composition on one substrate. One sample includes several Ti-xAl-yFe alloys at once. This combinatorial library dramatically reduces the time and cost of the investigation. The structure, mechanical and electrochemical properties of each new composition was studied using scanning electron microscopy (SEM) with energy-dispersive X-ray fluorescence analyzer (EDAX ZAF®), and electrochemical polarization method.
Sparse and accurate high resolution SAR imaging

We investigate the usage of an adaptive method, the Iterative Adaptive Approach (IAA), in combination with a maximum a posteriori (MAP) estimate to reconstruct high resolution SAR images that are both sparse and accurate. IAA is a nonparametric weighted least squares algorithm that is robust and user parameter-free. IAA has been shown to reconstruct SAR images with excellent side lobes suppression and high resolution enhancement. We first reconstruct the SAR images using IAA, and then we enforce sparsity by using MAP with a sparsity inducing prior. By coupling these two methods, we can produce a sparse and accurate high resolution image that are conducive for feature extractions and target classification applications. In addition, we show how IAA can be made computationally efficient without sacrificing accuracies, a desirable property for SAR applications where the size of the problems is quite large. We demonstrate the success of our approach using the Air Force Research Lab's "Gotcha Volumetric SAR Data Set Version 1.0" challenge dataset. Via the widely used FFT, individual vehicles contained in the scene are barely recognizable due to the poor resolution and high side lobe nature of FFT. However with our approach clear edges, boundaries, and textures of the vehicles are obtained.
Learning Mathematics in First-Grade Classrooms: On Whose Authority?

Integral to knowing mathematics is an understanding of how mathematical ideas are generated and validated. In mathematics classrooms, teachers socialize this understanding by establishing discourse patterns and participatory structures in which various sources—the teacher, the text, the discipline of mathematics, or the community of learners—are implicitly and explicitly credited with the authority to develop and validate mathematical ideas. In the present investigation, the authors focused on classroom discourse processes and participatory structures that grant sources of mathematical authority in 6 first-grade classrooms. In general, teachers firmly and with few exceptions positioned themselves as the sole mathematical authority in their classrooms. Yet, the authors found significant exceptions in 1 teacher’s lessons, with these exceptions inspiring possibilities in accomplishing the shift from a formal to a growth-and-change tradition of socializing students into the discipline of mathematics. Mathematical ideas, although oftentimes presented in textbooks, originate from human experience. Still, many of us turn to texts and to human experts to verify our ideas. Although there is nothing wrong with checking our ideas and formulations against those presented in books or by experts, this practice potentially hides the fact that these ideas and formulations originated from people. The fact that mathematics is a human invention (albeit, invented by extraordinary humans) may seem obvious, but it is not obvious to young students in American schools. Most students act as if mathematical ideas are predetermined and unarguable truths, which they either do or do not understand, but not ideas to which they could possibly contribute to or question (Schoenfeld, 1992; Stodolsky, 1988). Why would this be the case? In other words, why would students act as if they have no say in either the creation or verification of mathematical ideas? And, if we are to take recent reforms in mathematics education seriously, to have students vitally involved in conducting mathematical inquiry, how can we change this and promote students to take an active role in the creation and verification of mathematical ideas? These questions guide the study presented here.
Clock drawing in the oldest old

Abstract The present study investigated clock drawing performance by cognitively intact, elderly, community-dwelling individuals, with specific attention paid to the effects of age on both qualitative and quantitative features of performance. Comparison of three age groups (66–75, 76–84, and 85+) on a quantitative rating revealed no significant main effect. When specific qualitative features of performance (i.e., error types and planning strategies) were examined, no significant differences between groups were found. The results suggest that clock drawing ability is relatively preserved in healthy elderly individuals. Impaired clock drawing performance in cognitive screening of the elderly may indicate that further neuropsychological testing is warranted.
Stress changes in the femoral head due to porous ingrowth surface replacement arthroplasty

Finite element stress analyses were conducted of the canine femoral head before and after implantation of various surface replacement-type components. The femoral head was replaced by four implant geometries; (a) shell, (b) shell with peg, (c) shell with rod, and (d) a new epiphyseal replacement design. All implants were modelled to simulate bony ingrowth along the underside of the shell and along the surfaces of the peg and rod. The results indicated that in the normal femur the forces are transferred from the articular surface through the femoral head cancellous bone to the inferior cortical shell of the femoral neck. After shell-type surface replacement, forces were transferred more distally at the rim of the shell and at the end of the peg or rod, thereby reducing the stresses in the proximal head cancellous bone. Computer simulation of bone remodelling due to proximal bone stress reduction was shown to accentuate the abnormality of the stress fields. Surface replacement with a lower modulus material created a less abnormal redistribution of bone stresses. The new epiphyseal replacement design resulted in stress distributions similar to those in the normal femoral head and minimal shear stresses at the implant/bone interface. These findings suggest that the epiphyseal replacement concept may provide better initial mechanical integrity and create a more benign milieu for adaptive bone remodelling than conventional, shell-type surface replacement components.
Cross-application data provenance and policy enforcement

We present a new technique that can trace data provenance and enforce data access policies across multiple applications and machines. We have developed Garm, a tool that uses binary rewriting to implement this technique on arbitrary binaries. Users can use Garm to attach access policies to data and Garm enforces the policy on all accesses to the data (and any derived data) across all applications and executions. Garm uses static analysis to generate optimized instrumentation that traces the provenance of an application's state and the policies that apply to this state. Garm monitors the interactions of the application with the underlying operating system to enforce policies. Conceptually, Garm combines trusted computing support from the underlying operating system with a stream cipher to ensure that data protected by an access policy cannot be accessed outside of Garm's policy enforcement mechanisms. We have evaluated Garm with several common Linux applications. We found that Garm can successfully trace the provenance of data across executions of multiple applications and enforce data access policies on the application's executions.
The concept of solid solvent as a processing aid

The concept of solid solvent entails the use of low-molecular weight crystalline materials (LMC) as a processing aid. A LMC as an ideal solid solvent mixed into a polymer is expected to become a solvent for the polymer at high processing temperatures, reducing the melt viscosity and thus enhancing the processability, but to become a nonsolvent for the polymer at low use temperatures precipitating out of the polymer without adversely affecting the properties of the polymer. The feasibility of such a concept was examined using acetanilide as a potential solid solvent for polystyrene (PS) and two ABA-type block copolymers containing PS end blocks. Acetanilide demonstrated the essential features required of a solid solvent supporting the concept of solid solvent. It had a high solubility in PS at high temperatures very effectively reducing the melt viscosity of PS and the block copolymers, and it precipitated out of PS at low temperatures although it had an undesirably high residual solubility. The concept of solid solvent appears to be a viable one.
Duties and Responsibilities of Construction Managers: Perceptions of Parties Involved in Construction

This paper reports the findings of a study conducted by researchers at Illinois Institute of Technology under the direction and supervision of the ASCE Committee on Management Practices in Construction to investigate the expectations of the parties involved in the construction process, including designers, owners, general contractors, subcontractors, construction managers, and educators, relative to construction managers’ duties. The findings suggest that while there is some consensus among parties to a construction project relative to CM duties particularly in the construction phase, there is also some disagreement, most of which appear to be between contractors and designers. Most disagreements are related to CM duties performed in the bidding and postconstruction phases of projects.
Estrogen alters baseline and inflammatory-induced cytokine levels independent from hypothalamic–pituitary–adrenal axis activity

Abstract Although estrogen reduces inflammatory-mediated pain responses, the mechanisms behind its effects are unclear. This study investigated if estrogen modulates inflammatory signaling by reducing baseline or inflammation-induced cytokine levels in the injury-site, serum, dorsal root ganglia (DRG) and/or spinal cord. We further tested whether estrogen effects on cytokine levels are in part mediated through hypothalamic–pituitary–adrenal (HPA) axis activation. Lumbar DRG, spinal cord, serum, and hind paw tissue were analyzed for cytokine levels in 17β-estradiol-(20%) or vehicle-(100% cholesterol) treated female rats following ovariectomy/sham adrenalectomy (OVX), adrenalectomy/sham ovariectomy (ADX) or ADX + OVX operation at baseline and post formalin injection. Formalin significantly increased pro-inflammatory interleukin (IL)-6 levels in the paw, as well as pro- and anti-inflammatory cytokine levels in the DRG, spinal cord and serum in comparison to naive conditions. Estrogen replacement significantly increased anti-inflammatory IL-10 levels in the DRG. Centrally, estradiol significantly decreased pro-inflammatory tumor necrosis factor (TNF)-α and IL-1β levels, as well as IL-10 levels, in the spinal cord in comparison to cholesterol treatment. At both sites, most estradiol modulatory effects occurred irrespective of pain or surgical condition. Estradiol alone had no influence on cytokine release in the paw or serum, indicating that estrogen effects were site-specific. Although cytokine levels were altered between surgical conditions at baseline and following formalin administration, ADX operation did not significantly reverse estradiol’s modulation of cytokine levels. These results suggest that estrogen directly regulates cytokines independent of HPA axis activity in vivo , in part by reducing cytokine levels in the spinal cord.
Bridged peptide macrocycles as ligands for PDZ domain proteins.

Conformationally constrained side chain-bridged cyclic peptides were prepared using bis-carboxylic acid ring spacers. These macrocyles were designed to inhibit protein−protein interactions mediated by the third PDZ domain (PDZ3) of a mammalian neuronal protein, PSD-95. Isothermal titration calorimetry (ITC) experiments measured dissociation constants in the low micromolar range. For each compound, the change in entropy (TΔS) of binding either is comparable in magnitude to the enthalpy change (ΔH) or is the predominant driving force for association.
On the combustion kinetics of heterogeneous char particle populations

A laboratory-scale laminar flow reactor is used to measure char combustion rates under conditions simulating those found in pulverized coal-fired boilers. In the present article, a unique optical technique is used to measure, in situ , the temperatures, sizes, and velocities of individual burning char particles from Pocahontas #3 low-volatile bituminous coal. These optical data are used in conjunction with a model of surface reaction and gas-particle transport processes to compute single-particle burning rates and global, n th -order rate coefficients. The optical technique records a broad distribution of char particle temperatures at any given location in the laminar flow combustor. When single-particle rate coefficients are derived from these optical data, characteristic features are observed on Arrhenius plots, consisting of distinct, linear groupings of single-particle rate coefficients. These linear features are shown to be the outlines of characteristics curves representing the equations governing gas-particle transport processes. The linear groupings of rate coefficients, like the theoretical characteristic curves they follow, exhibit pseudo activation energies that are independent of the actual global kinetic activation energy. The characteristic curve concept is used to discuss the features of single-particle combustion. Particle-to-particle variations in reactivity and physical properties are identified as the origin of the particle temperature distributions and of the linear features on Arrhenius plots. It is shown that no singl,, simple rate expression is capable of describing the unique combustion behavior of each particle. This fact notwithstanding, many applications require simple rate expressions that approximately describe the combustion behavior of the marcoscopic sample. Techniques for determining such rate expressions for heterogeneous particle populations are evaluated.
Advanced Imaging of Chronic Pancreatitis

Chronic pancreatitis is characterized by continuing inflammation, destruction, and irreversible morphological changes in the pancreatic parenchyma and ductal anatomy. These changes lead to chronic pain and/or loss of function. Although these definitions are simple, the clinical diagnosis of chronic pancreatitis remains difficult to make, especially for early disease. Routine imaging modalities such as transabdominal ultrasound and standard CT scans are insensitive for depicting early disease, and detect only advanced chronic pancreatitis. Advances in imaging modalities including CT, MRI with gadolinium contrast enhancement, MRI with magnetic resonance cholangiopancreatography (MRI/MRCP), MRI/MRCP with secretin-stimulation (S-MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS) allow earlier diagnosis of chronic pancreatitis. This article reviews the recognized findings, advantages, and disadvantages of the various imaging modalities in the management of chronic pancreatitis, specifically CT, MRI with or without MRCP and/or S-MRCP, ERCP, and EUS.
The acoustics of mandolins

Using electronic TV holography, we have studied the vibrational modes of four mandolins and a mandola. The lowest (0,0) modes may appear either as a triplet (as in a guitar) or as a doublet. The modal frequencies correlate well with the frequency response curves. Sound spectra indicate that sound radiation is quite uniform over the 0–5 kHz range with some rolloff above 2.5 kHz.
Scattering of 5 and 15 keV H+ from surfaces

Abstract The distribution in energy and angle of recoil H + and H − have been measured for 5 and 15 keV H + impact on Be, C, Cu and Nb. Incidence on the surface is at 69° from the normal and recoil direction is 90° to 75° from the normal, providing a geometry of near grazing incidence and emergence. The measured scattering coefficients for the different target materials are not in the ratios expected from the simple relationship between scattering cross sections. Apparent scattering coefficients are found to vary with projectile dose due to the build up of polymerized carbon on the surface.