cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential pH measurements of metabolic cellular activity in nl culture volumes using microfabricated iridium oxide electrodes.

Abstract In this paper we describe a new approach to measure pH differences in microfluidic devices and demonstrated acidification rate measurements in on-chip cell culture systems with nl wells. We use two miniaturized identical iridium oxide (IrOx) thin film electrodes (20 μm × 400 μm), one as a quasi-reference electrode, the other as a sensing electrode, placed in two confluent compartments on chip. The IrOx electrodes were deposited onto microfabricated platinum (Pt) electrodes simultaneously using electrodeposition. Incorporating the electrodes into a microfluidic device allowed us to expose each electrode to a different solution with a pH difference of one pH unit maintaining a confluent connection between the electrodes. In this configuration, we obtained a reproducible voltage difference between the two IrOx thin film electrodes, which corresponds to the electrode sensitivities of −70 mV/pH at 22 °C. In order to measure the acidification rate of cells in nl cell culture volumes we placed one IrOx thin film electrode in the perfusion channel as a quasi-reference electrode and the other in the cell culture volume. We obtained an acidification rate of 0.19 ± 0.02 pH/min for fibroblast cells using a stop flow protocol. These results show that we can use two identical miniaturized microfabricated IrOx electrodes to measure pH differences to monitor the metabolic activity of cell cultures on chip. Furthermore, our approach can also be applied in biosensor or bioanalytical applications.
Infrared spectroscopic studies on forage and by-product fibre fractions and lignin determination residues

Abstract The objective was to define the nature of the plant fraction identified as lignin by various procedures. Seven materials (alfalfa, orchardgrass, red clover, and switchgrass hays, a mixed hay, peanut hulls and wheat straw) were examined. The following lignin determination procedures were studied: 72% sulphuric acid, permanganate, chlorite and triethylene glycol, using a variety of combinations of fibre source (acid detergent, hot water/organic solvent and 0.5% ammonium oxalate extracted) and lignin determination procedures. Fractions were examined by infrared spectroscopy in an effort to determine the compositional changes induced by the various chemical procedures. Results showed large differences in the spectra obtained by the various procedures and indicated severe problems for the various lignin assays. The most common problem was the tendency for at least some crude protein to be included as part of the lignin value. The chlorite and triethylene glycol methods for lignin determination did not appear to remove all the lignin present, and there was some indication of carbohydrate extraction by the various procedures. Sulphuric acid showed retention of protein and perhaps carbohydrate. Finally, the problems varied both with the assay in question and with the material being assayed.
Possible mechanisms of photoreceptor damage by light in mammalian eyes

Abstract Retinal damage by light denotes cell lethal and sub-lethal effects of visible light which have a non-thermal cause. The damage may be a primary or secondary manifestation of the action of light depending upon whether the damaged cell is also the site of the action of light on the photoreactivc molecule. The action spectrum of the damaging reaction may identify the reactive molecule but this determination is not a straightforward one. Evidence from different lines of experimentation and deduction indicates that the light damage in the rat from exposure for several hours or days is initiated by rhodopsin absorption. Based upon experiences with different physical or chemical agents that have selective effects upon the rod cell or the pigment epithelium, two kinds of rhodopsin-mediated damage are discussed. They are distinguished especially by the participation of the pigment epithelium, the magnitude of sub-lethal effects in relation to rod cell death, and the sensitizing effects of long-term adaptation to darkness or weak cyclic light. The mutant (rdy) rat is abnormally susceptible to both kinds of damage. Three possible mechanisms for damage are considered; photooxidation, retinol induced membranolysis and transformation of a physiological response of the rod cell to a damaging, degrading effect when light is “unphysiologically” strong (rhodopsin bleaching of 15–90% for 2–6 days). Various kinds of blue-light mediated damage as observed in the monkey may involve the “blue” cone pigment, a photosensitizer such as riboflavin within retinal cells or other sensitizers in pigment epithelium and choriod.
Does existing measurement theory support the use of composite and causal indicators in information systems research

Despite lingering concerns surrounding the use of composite and causal indicators, a significant number of information systems researchers continue to employ them in their work. The authors suggest that misunderstandings about the appropriateness of implementing composite and causal indicators can be traced to the absence of measurement theory supporting their use. Recommendations on how researchers might design studies that avoid the use of these respective indicators are also provided.
Another restriction on weak neutral currents

Abstract A restriction on the role of weak neutral currents is derived from a calculation of the Cabibbo angle. Only ‘universally coupled’ neutral V ± A currents of the type encountered in the Schizon model of Lee and Yang appear to satisfy this restriction easily.
A comparison of laryngoplasty and modified partial arytenoidectomy as treatments for laryngeal hemiplegia in exercising horses.

Objective— To compare upper airway mechanics, arterial blood gases, and tracheal contamination in horses with induced left laryngeal hemiplegia (recurrent laryngeal neuropathy [RLN]) treated by laryngoplasty/vocal cordectomy (LPVC) or modified partial arytenoidectomy (MPA). Study Design— Repeated measures under the following conditions: Control, RLN, LPVC, and MPA. Animals— Six horses. Methods— Two trials were conducted under all conditions at 80% and 100% of maximal heart rate (HRmax). In Trial 1, arterial blood gases, tracheal and pharyngeal pressures, and laryngeal videoendoscopy were recorded. In Trial 2, upper airway pressure and airflow were determined. Tracheobronchial aspirates were performed after exercise to quantify airway contamination. Results— Compared with control, RLN significantly increased inspiratory impedance and worsened exercise-induced hypoxemia. At 80% HRmax, LPVC restored most variables to control values. At 100% HRmax, LPVC improved all variables, but did not restore minute volume, arterial pH, and PaCO2. At 80% HRmax, MPA restored all variables except bicarbonate to control values. At 100% HRmax, MPA improved all variables, but did not statistically restore minute ventilation or bicarbonate level. Only minor differences were noted between LPVC and MPA. Both resulted in equivalent tracheal contamination. Conclusions— Airway mechanics and arterial blood gas values were not restored to normal after either LPVC or MPA in horses exercising at HRmax. This does not affect ventilation at sub-maximal exercise, but has clinical implications at HRmax. Both procedures diminish normal laryngeal protective mechanisms. Clinical Relevance— At sub-maximal exercise intensities both LPVC and MPA restore airway ventilation to normal. At maximal exercise the superiority of LPVC over MPA is slight.
Parent–Child Conflict and Early Childhood Adjustment in Two-Parent Low-Income Families: Parallel Developmental Processes

Parent–child conflict is central to most intervention models focused on reducing child problem behavior, yet few longitudinal studies have examined these processes during early childhood. The current study investigates (1) growth in mother–child and father figure (FF)–child conflict, (2) associations between trajectories of mother–child and FF–child conflict and children’s adjustment; and (3) intervention effects in attenuating conflict. Participants are 195 ethnically diverse mother–FF–child triads drawn from a larger parenting intervention study for families with children at risk for developing conduct problems. Mother–child conflict decreased from ages 2 to 4, but decreases were unrelated to changes in children’s adjustment problems. In contrast, the slope of FF–child conflict was positively related to the slope of child externalizing behaviors. Random assignment to a family-centered parenting intervention predicted rate of decline in mother–child conflict. Findings are discussed with respect to developmental patterns of parent–child conflict in early childhood and implications for prevention.
The Effects of Interview Structure on Recruiting Outcomes

Two laboratory experiments explored the effects of interview structure on evaluations and perceptions of the interview and organization. In the first experiment, subjects were presented with transcripts of interviews and were found to react more favorably to unstructured interviews. This effect was somewhat stronger when there was no information on the job and organization. In the second experiment, participants were presented with profiles of interviews that varied on interviewer warmth and 3 attributes commonly associated with structured interviews (job relevance, low voice, standardization). Participants preferred interviews that were low on job relevance, high on voice, low on standardization, and high on warmth. The preference for low standardization was most pronounced when there was high voice than when there was low voice.
Copper Transport Activity of Yeast Ctr1 Is Down-regulated via Its C Terminus in Response to Excess Copper

Copper is an essential yet toxic trace element. The Ctr1 family of proteins plays a critical role for copper uptake in eukaryotes. However, the mechanisms of action of Ctr1 are largely unknown. Our previous data demonstrated that copper transport induces conformational changes in the cytosolic C terminus of the yeast Saccharomyces cerevisiae Ctr1. To define the physiological significance of this molecular event and gain better insights into the mechanism of Ctr1-mediated copper uptake, we have characterized the functional roles of the Ctr1 C terminus. A Ctr1 mutant lacking the entire C-terminal cytosolic tail is functional in high affinity copper uptake; however, yeast cells expressing this mutant are extremely sensitive to excess copper. Toxic copper uptake is not attributed to elevated expression or distinct subcellular localization of this mutant as compared with wild type Ctr1. Further characterization of the function of Ctr1 containing deletions or site-directed mutations at the C terminus indicates a structural role for the C terminus in controlling Ctr1 activities. In response to excess copper, Ctr1-mediated copper transport is rapidly blocked in a C terminus-dependent mechanism associated with direct binding of copper. We propose that conformational changes in the cytosolic tail of yeast Ctr1 by copper sensing within this domain lead to the inhibition of Ctr1-mediated copper transport. These data suggest a new regulatory mechanism by which yeast cells maintain homeostatic copper acquisition.
Nanophase Ni particles produced by a blown arc method

Nanophase Ni particles (<10 nm in diameter) were produced by a blown arc method. A helium gas stream directed at the arc reduces the Ni vapor concentration and increases the quench rate. The helium gas velocity is the predominant factor influencing the size of the Ni particles. Gas velocities of 20 m/s and 56 m/s (at 26.6 kPa total helium pressure) resulted in Ni particle sizes of 13 nm and 7 nm, respectively.
The effects of informational feedback and self-beliefs on the motivation to perform a self-regulated task

Abstract College students were given the opportunity to perform a self-regulated task, specifically to voluntarily write test items in return for grade points based on number and type of items written. High-third point-getters received a double grade bonus, middle-third point-getters a single bonus, and low-third point-getters no bonus. One group was given no informational feedback regarding their weekly relative position in points while a second group was given explicit informational feedback. Subjects in the no feedback condition who were high in their belief in their own performance capability outperformed their counterparts in the feedback condition. The reverse was true for subjects of middle and low self-perceived capability where feedback receivers outperformed those receiving no feedback. Student self-competence beliefs moderated the relationship between amount of informational feedback and performance suggesting that different types of students need to be motivated in different ways.
Prostaglandins do not mediate interferon-α effects on mouse behavior

Abstract Interferons play an important role in cell function as well as host defense against virus infection. Interferon-α stimulates cyclooxygenase-catalyzed prostaglandin synthesis. Therefore, a cyclooxygenase inhibitor was used to determine whether the behavioral effects of mouse interferon-α in mice are mediated by increased prostaglandin synthesis. Male DBA/2J mice were exposed to 1600 U/g mouse interferon-α, the buffer in which the interferon was diluted, 5 mg/kg of a cyclooxygenase inhibitor, indomethacin, or 5 mg/kg indomethacin plus 1600 U/g mouse interferon-α. As in previous studies, interferon decreased activity and food pellets obtained in the first 4 hours after administration. Indomethacin had no effect on this effect of interferon; therefore, we conclude that the behavioral effects of interferon are not mediated by the fever or anoretic effects of prostaglandins.
NMR Studies of H2O: N-Phenyl (N-Phenyl-β-D-Glucopyranosylamine) Urokamide Interactions in Dimethyl Sulfoxide at two Fields

Abstract During the course of NMR structural investigations of the title compound (N-phenyl uronamide) we noticed the presence of a strong H2O activity-dependent NOE between the small amount of H2O associated with the carbohydrate's hydroxyl protons in solutions of DMSO-d6 . The -OH/H2O off-diagonal t1 slices displayed a NOESY τm-dependence similar to molecules (τc = 0.1–5 ns) experiencing slow exchange (1–10 s−1). From T1 data at two fields a τc for the title compound was calculated to be ca. 0.54 ns at 313 K. The -OH/H2O exchange rate constant, K, increased from 0.32 to 11.14 s−1 as the molar ratio of [H2O]:[N-phenyl uronamide] increased from ca. 4.5 to 5.2. The latter finding indicated that the -OH/H2O proton exchange process, which is strongly affected by the translational diffusion of H2O, diminished as [H2O] approached that which was inherently a complex in the crystalline structure (e.g., C18H20O5N2·4H2O) and was, presumably, tightly hydrogen-bound to the -OH/NH funtional groups. To test this, the ...
Cognitive impairment and resource use of nursing home residents: a structural equation model.

Background.Only a few studies have examined relationships between cognitive impairment and resource use of nursing home residents, and these studies have yielded mixed results.Objectives.To develop and test structural equation models for relationships between cognitive impairment, covariates, and re
Dicyclic and Tricyclic Diaminopyrimidine Derivatives as Potent Inhibitors of Cryptosporidium parvum Dihydrofolate Reductase: Structure-Activity and Structure-Selectivity Correlations

A structurally diverse library of 93 lipophilic di- and tricyclic diaminopyrimidine derivatives was tested for the ability to inhibit recombinant dihydrofolate reductase (DHFR) cloned from human and bovine isolates of Cryptosporidium parvum (J. R. Vasquez et al., Mol. Biochem. Parasitol. 79:153-165, 1996). In parallel, the library was also tested against human DHFR and, for comparison, the enzyme from Escherichia coli. Fifty percent inhibitory concentrations (IC(50)s) were determined by means of a standard spectrophotometric assay of DHFR activity with dihydrofolate and NADPH as the cosubstrates. Of the compounds tested, 25 had IC(50)s in the 1 to 10 microM range against one or both C. parvum enzymes and thus were not substantially different from trimethoprim (IC(50)s, ca. 4 microM). Another 25 compounds had IC(50)s of 10 microM) and thus were not considered to be of interest as drugs useful against this organism. A good correlation was generally obtained between the results of the spectrophotometric enzyme inhibition assays and those obtained recently in a yeast complementation assay (V. H. Brophy et al., Antimicrob. Agents Chemother. 44:1019-1028, 2000; H. Lau et al., Antimicrob. Agents Chemother. 45:187-195, 2001). Although many of the compounds in the library were more potent than trimethoprim, none had the degree of selectivity of trimethoprim for C. parvum versus human DHFR. Collectively, the results of these assays comprise the largest available database of lipophilic antifolates as potential anticryptosporidial agents. The compounds in the library were also tested as inhibitors of the proliferation of intracellular C. parvum oocysts in canine kidney epithelial cells cultured in folate-free medium containing thymidine (10 microM) and hypoxanthine (100 microM). After 72 h of drug exposure, the number of parasites inside the cells was quantitated by indirect immunofluorescence microscopy. Sixteen compounds had IC(50)s of <3 microM, and five of these had IC(50)s of <0.3 microM and thus were comparable in potency to trimetrexate. The finding that submicromolar concentrations of several of the compounds in the library could inhibit in vitro growth of C. parvum in host cells in the presence of thymidine (dThd) and hypoxanthine (Hx) suggests that lipophilic DHFR inhibitors, in combination with leucovorin, may find use in the treatment of intractable C. parvum infections.
New method for the preparation of thick conducting polymer composites

A highly porous and absorbable crosslinked polystyrene, prepared by the concentrated emulsion polymerization method, was used as host polymer for the preparation of conducting, large objects, polymer composites. The composites, whose conductivity can be as high as 0.80 S/cm, were prepared by (i) imbibing the host polymer with a pyrrole (or oxidant) solution, (ii) partially drying the imbibed host polymer, and (iii) imbibing again with an oxidant (or pyrrole) solution for polymerization to take place. The electrical conductivity of the composite and the penetration of polypyrrole in the host polymer are influenced by the polymerization conditions (i.e., the concentrations of oxidant and pyrrole and the nature of the solvents used for the oxidant and pyrrole), the order in which the two imbibing solutions are introduced, and the drying time used after the first imbibation. The mechanical properties of the host polymer are improved with the incorporation of polypyrrole. Scanning electron micrographs of the composites indicate that the polypyrrole coats uniformly as a film the inside of the porous host polymer.
Evidence for Mediated Transport of Chloride in Cat Cerebral Cortex in vitro

The kinetics of the uptake of chloride by slices of cat cerebral cortex incubated in vitro have been studied for a wide range of concentrations of chloride and potassium in the incubation media.
Wealth and the affordability of health insurance.

Between 2000 and 2005, the number of uninsured people in the USA has grown from 40 million to almost 47 million [1]. This has led to much debate over how many of these people can really afford insu...
Connecting the Reentrant Insulating Phase and the Zero-Field Metal-Insulator Transition in a 2D Hole System

We present the transport and capacitance measurements of 10 nm wide GaAs quantum wells with hole densities around the critical point of the 2D metal-insulator transition (critical density p(c) down to 0.8 × 10(10)/cm2, r(s) ∼ 36). For metallic hole density p(c) < p < p(c) + 0.15 × 10(10)/cm2, a reentrant insulating phase (RIP) is observed between the ν = 1 quantum Hall state and the zero-field metallic state and it is attributed to the formation of pinned Wigner crystal. Through studying the evolution of the RIP versus 2D hole density, we show that the RIP is incompressible and continuously connected to the zero-field insulator, suggesting a similar origin for these two phases.
Failed Endoscopic Therapy and the Interventional Radiologist: Non-Variceal Upper Gastrointestinal Bleeding

The exact site of nonvariceal upper gastrointestinal bleeding is not always visualized by endoscopy. In these instances, other modalities must be utilized to isolate and treat the bleeding site. Angiography and transcatheter embolization provide a nonoperative option for patients whose bleeding has either not been controlled or not identified under endoscopy. Technically successful transcatheter embolization has been shown to significantly reduce mortality in patients with UGI hemorrhage. Temporary embolization agents like Gelfoam and permanent agents like polyvinyl alcohol, cyanoacrylic glues, and coils are used to embolize bleeding lesions. In patients with UGI hemorrhage that do not demonstrate bleeding on angiography, some authors have advocated prophylactic embolization of the left gastric artery. Major complications are unusual. While embolotherapy may not always be a permanent cure, it may stabilize the patient until definitive therapy/surgery is performed.
A Non-Local Visco-Plastic Model With Strain Laplacian Effects and Interphase Effects for Simulating the Stiffness and Yield Strength of a Class of Polymer Nanocomposites

Numerical simulation of nanocomposite mechanics Representative Volume Elements (RVE) that include nanostructural information is a powerful and popular current approach. However, some limitations exist for this method, for example, the large difference between the Young’s moduli of the nanoparticles and the matrix materials causes large strain gradients around the nanoparticles or effective particles which presents numerical difficulties. Also the nanoscale mesh size requires extremely small time steps and therefore high computational costs, especially for dynamic simulations. In the present investigation, an analytical constitutive model is developed by adding the interphase effects and strain gradient effects to a classic spring-dashpot viscoplastic model of polymers. It is shown that this model can predict the constitutive behavior quantitatively. The mechanism of a brittle to ductile transition can also be captured and studied. Useful information for material design can be obtained through parameter study of the current model.Copyright © 2008 by ASME
Changing perceptions of West Africa's past: Archaeological research since 1988

Archaeological research since 1988 in West Africa has focused almost exclusively on the period since 10,000 B.P. Significant advances have been made in our understanding of the Late Stone Age in the Sahara and Savanna zones, the advent of metallurgy and subsequent changes in metal technology, and the comparative trajectories of complex societies in different regions. Increasingly, data are being recovered that fail to conform to earlier Eurocentric assumptions emphasizing linear, progressive change through a series of evolutionary “ages and stages.” The search for new, more appropriate models for interpreting West Africa's past has infused the discipline with great theoretical vitality. Both ethnoarchaeological studies and traditional archaeological research programs in West Africa are contributing substantially to the articulation of new theoretical frameworks for African archaeology and potentially for the discipline as a whole.
A critique of impedance measurements in cardiac tissue

The specific impedance of cardiac tissue cannot be measured directly. Instead, the investigator obtains voltage and current measurements and places them into a model of the tissue's structure to infer the impedances of elements of the model. If the model fails to describe major aspects of the real tissue, the results may be worthless, although possibly self-consistent. In the literature of impedance measurement in cardiac tissue, only rarely is the model explicitly described; more commonly, the tissue model is adopted implicitly when equations giving the impedance in terms of voltage and current measurements are adopted. This paper examines the series of models that have been used in specific impedance measurements of cardiac tissue and shows how the same or similar measurements can accurately describe tissue impedivity or can lead to significant errors when inadequate models such as isotropic and anisotropic monodomains (although a part of work of historical merit) are used.
New uses for old drugs

It takes too long and costs too much to bring new drugs to market. So let's beef up efforts to screen existing drugs for new uses, argue Curtis R. Chong and David J. Sullivan Jr. Drug rediscovery is becoming big business. It is so costly to bring a new drug to market that drug companies are looking at their back catalogues and patent expirations with a new eye. As Curtis R. Chong and David J. Sullivan Jr explain, the screening of existing drugs for new activities is a valuable short-cut between the lab and the clinic. And a comprehensive screening campaign could be particularly useful in uncovering treatments for neglected diseases.
Hereditary Osteodystrophy with Multiple Hormone Resistance—A Case Report

Hereditary Osteodystrophy, also called pseudohypoparathyroidism, Type 1A (PHP), is a very rare condition composed of a heterogeneous group of autosomal dominant disorders with the common feature of organ resistance to multiple hormones. These patients produce the right amount of hormones but there is resistance to its effect. PHP is difficult to diagnose and the lack of diagnosis may have serious implications for the patient. We report a case of PHP, diagnosed by the dentist, due to the dental and jaw manifestations.
The pathogenesis of normal pressure hydrocephalus: a theoretical analysis.

Hydrocephalus is an abnormal accumulation of cerebrospinal fluid (CSF) in the cerebral ventricles, usually caused by impaired absorption of the fluid into the bloodstream. Despite obstructed absorption and continued secretion of CSF into the ventricles at a near normal rate, the ventricular CSF pressure (VCSFP) is often normal. We attempt to understand how hydrocephalus can exist with normal VCSFP by exploring the role of the brain parenchyma in absorbing CSF in hydrocephalus. We test three theories: (1) the ventricular wall is impermeable to CSF; (2) ventricular CSF seeps into the parenchyma, from which it is efficiently absorbed; and (3) ventricular CSF seeps into the parenchyma but is absorbed inefficiently. We model the brain as a thick spherical shell consisting of a porous, elastic, solid matrix, containing interstitial fluid and blood. We modify the equations of poroelasticity, which describe flow of fluid through porous solids, to allow for parenchymal absorption. For each of the three theories we calculate the steady state changes in VCSFP and in parenchymal fluid pressure caused by an incremental defect in CSF absorption. We also calculate the steady state changes in fluid content, tissue volume, tissue displacement, and stresses caused by a small increment of VCSFP. We conclude that only the second theory—seepage of CSF with efficient parenchymal absorption—accounts for the clinical features of normal pressure hydrocephalus. These features include sustained ventricular dilatation despite normal VCSFP, increased periventricular fluid content, and localized periventricular white matter damage.
Huffman encoding of test sets for sequential circuits

Sequential circuits are hard to test because they contain a large number of internal states that are difficult to control and observe. Scan design is often used to simplify testing; however, scan is not always applicable because of area and performance penalties. Recent advances in sequential circuit testing have led to techniques and tools that provide test sets with high coverage of single stuck-line (SSL) faults for nonscan circuits. However, these test sets contain a large number of patterns and require a tester with considerable pattern depth. We investigate the application of Huffman codes to pattern encoding. This allows the use of low-cost testers that do not require excessive memory. Our method is especially applicable to nonscan and partial-scan embedded core circuits. We demonstrate the feasibility of our approach by applying it to SSL test sets for the ISCAS'89 benchmarks.
Case report of spontaneous hemorrhage in a sublingual arteriovenous malformation causing an emergent airway obstruction

The literature is devoid of articles on spontaneous orofacial hemorrhage with hematoma formation without an underlying condition. Rupture of an arteriovenous malformation (AVM) is possibly the rarest form of spontaneous hemorrhage and life-threatening hematoma formation. This pathology is widely known because of its occurrence in the central nervous system, but it can appear in any location. AVM is not generally thought to be an inherited disorder, except in the context of a specific hereditary syndrome. AVMs can be seen using computerized tomographic angiography, but distraction angiography is the gold standard for diagnosis and treatment decision making. Surgery is the mainstay of treatment; however, endovascular embolization has become an important adjunct to surgical intervention. With shrinkage of the lesion or definitive treatment with coils, particles, or glue. Other important considerations in the choice of treatment are the patient's age, lesion size and location, and prior history of hemorrhage.
Application of feature extraction methods for landmine detection using the Wichmann/Niitek ground-penetrating radar

Ground-penetrating radar (GPR) has been proposed as an alternative to classical electromagnetic induction techniques for the landmine detection problem. The Wichmann/Niitek system provides a good platform for novel GPR-based antitank mine detection and classification algorithm development due to its extremely high SNR. When the GPR sensor is mounted on a moving vehicle, the target signatures are hyperbolas in a time-domain data record. The goal of this work is to extract useful features that exploit this knowledge in order to improve target detection. The algorithms can be divided into two steps: feature extraction and classification. Preprocessing is also considered to remove both stationary effects and nonstationary drift of the data and to improve the contrast of the desired hyperbolas. The algorithm is evaluated using real data over primarily plastic antitank mines collected with a fielded GPR sensor at a government test site.
MATCHING AND EFFICIENCY IN COHORT STUDIES

Contrary to the impression given in some textbooks, matching can reduce the efficiency of a cohort study, even when it produces no sample-size reduction and even if the matching variable is a confounder. The authors illustrate this along with some additional points regarding cohort matching. First, the impact of matching on efficiency can be in opposite directions for different measures of effect; as a consequence, criteria for deciding whether to match must depend on whether one wishes to estimate relative or absolute effects. Second, the commonly drawn analogy between blocking in randomized trials and matching in cohort studies is misleading when one considers the impact of matching on covariate distributions. Third, the conditions for efficiency overmatching in a cohort study are different from the conditions in a case-control study. It appears that, under an additive model, matching will usually increase the efficiency of both risk-difference and risk-ratio estimation, and the power of the Mantel-Haenszel test. Under a multiplicative model, the impact of matching is not as consistently beneficial. The authors present some approximate criteria which allow one to use a priori information to predict whether cohort matching is likely to improve efficiency.
Metallic multilayers and superlattices

An introduction to metal-metal multilayers and superlattices is presented, along with a brief review of some of the materials which have been made in our lab, and phenomena which have been observed, so far. The results of a number of x-ray structural characterization techniques we have applied to these materials are described. These include Bragg θ-2θ x-ray diffraction, transmission and reflection Laue diffraction, and wide-film Debye-Scherrer diffraction. Emphasis is placed on recent results obtained in our laboratory with multilayers and superlattices produced by sputtering techniques.
The Black Male and the U.S. Economy

This article examines the current status of black males in the U.S. economy. It emphasizes several positive aspects of the changing status of black males over time. The authors acknowledge that the social and economic conditions of black males in the United States are troubling in many respects. However, the objective of the article is to highlight the progress and achievements of black males. Most research on black males focuses solely on the problems and rarely documents the successes and accomplishments. Black males have made significant contributions to the U.S. economy. However, little attention has been paid in the literature to their achievements in education, their professional successes, and their positive community and family involvement.
Evaluation of Retinal and Choroidal Thickness by Swept-Source Optical Coherence Tomography: Repeatability and Assessment of Artifacts

Purpose To determine the repeatability of automated retinal and choroidal thickness measurements with swept-source optical coherence tomography (SS OCT) and the frequency and type of scan artifacts. Design Prospective evaluation of new diagnostic technology. Methods Thirty healthy subjects were recruited prospectively and underwent imaging with a prototype SS OCT instrument. Undilated scans of 54 eyes of 27 subjects (mean age, 35.1 ± 9.3 years) were obtained. Each subject had 4 SS OCT protocols repeated 3 times: 3-dimensional (3D) 6 × 6-mm raster scan of the optic disc and macula, radial, and line scan. Automated measurements were obtained through segmentation software. Interscan repeatability was assessed by intraclass correlation coefficients (ICCs). Results ICCs for choroidal measurements were 0.92, 0.98, 0.80, and 0.91, respectively, for 3D macula, 3D optic disc, radial, and line scans. ICCs for retinal measurements were 0.39, 0.49, 0.71, and 0.69, respectively. Artifacts were present in up to 9% scans. Signal loss because of blinking was the most common artifact on 3D scans (optic disc scan, 7%; macula scan, 9%), whereas segmentation failure occurred in 4% of radial and 3% of line scans. When scans with image artifacts were excluded, ICCs for choroidal thickness increased to 0.95, 0.99, 0.87, and 0.93 for 3D macula, 3D optic disc, radial, and line scans, respectively. ICCs for retinal thickness increased to 0.88, 0.83, 0.89, and 0.76, respectively. Conclusions Improved repeatability of automated choroidal and retinal thickness measurements was found with the SS OCT after correction of scan artifacts. Recognition of scan artifacts is important for correct interpretation of SS OCT measurements.
Pronoun case overextensions and paradigm building

Pronoun case errors, or overextensions, like *me want it are characteristic of English child language. This paper explores a hypothesis that the morphological structure of a pronoun influences the pattern of these errors. The Language Acquisition Device (LAD) attempts to analyse English pronoun case forms into stems and affixes, but cannot because of their irregularity. Nevertheless the LAD extracts a phonetic core for each pronoun (e.g./m-/ for the 1st sg.,/h-/ for the 3rd masc. sg.). The phonetic core blocks the overextension of suppletive nominative forms like I and she. This hypothesis predicts strong differences in the frequency and types of errors between pronouns with suppletive nominatives and those without. Evidence for this hypothesis was found in a transcript database of twelve children, with data collected in one hour samples every month from 1;0 to 3;0. 20,908 pronouns were examined, 1347 of which were errors. Statistical analyses of these data provide support for this hypothesis.
Ependymal changes in the human fetal brain

Focal ependymal loss, increasing in extent with advancing gestational age, was found in 111 human fetal brains. Its regular occurrence in specific sites, viz, the lateral walls of the lateral ventricles, over sector CA2 of the hippocampus, and on the ventral surface of the corpus callosum and lateral walls of the septum pellucidum, without prominent subependymal gliosis, suggests that restricted ependymal loss may be related to growth and development of the fetal brain. More extensive loss should be considered a marker of a neuropathological process.
Spectral asymmetry and Riemannian geometry. III

1. Introduction. The main purpose of this paper is to present a generalization of Hirzebruch's signature theorem for the case of manifolds with boundary. Our result is in the framework of Riemannian geometry and can be viewed as analogous to the Gauss–Bonnet theorem for manifolds with boundary, although there is a very significant difference between the two cases which is, in a sense, the central topic of the paper. To explain this difference let us begin by recalling that the classical Gauss–Bonnet theorem for a surface X with boundary Y asserts that the Euler characteristic E(X) is given by a formula:where K is the Gauss curvature of X and σ is the geodesic curvature of Y in X. In particular if, near the boundary, X is isometric to the product Y x R+, the boundary integral in (1.1) vanishes and the formula is the same as for closed surfaces. Similar remarks hold in higher dimensions. Now if X is a closed oriented Riemannian manifold of dimension 4, there is another formula relating cohomological invariants with curvature in addition to the Gauss–Bonnet formula. This expresses the signature of the quadratic form on H2(X, R) by an integral formulawhere p1 is the differential 4-form representing the first Pontrjagin class and is given in terms of the curvature matrix R by p1 = (2π)−2Tr R2. It is natural to ask if (1.2) continues to hold for manifolds with boundary, provided the metric is a product near the boundary. Simple examples show that this is false, so that in general
Rape and the reasonable man

Standards of reasonability play an important role in some of the most difficult cases of rape. In recent years, the notion of the "reasonable person" has supplanted the historical concept of the "reasonable man "a s the test of reasonability. Contemporary feminist critics like Catharine MacKinnon and Kim Lane Scheppele have challenged the notion of the reasonable person on the grounds that reasonability standards are "gendered to the ground" and so, in prac- tice, the reasonable person is just the reasonable man in a gender neutral guise. These critics call for the explicit employment of a "reasonable woman" standard for application to the actions of female victims of rape. But the arguments for abandoning a gender-neutral standard are double-edged and the employment of gendered standards of reasonability is likely to have implications that are neither foreseen by, nor acceptable to, advocates of such standards. Reasonable agent standards can be dropped, in favor of appeals to the notion of a "reasonable demand (or expectation)" by the law. However, if reasonable agent standards are to be retained, gendered versions of such standards are not preferable to gender-neutral ones.
A unified framework for estimating diffusion tensors of any order with symmetric positive-definite constraints

Cartesian tensors of various orders have been employed for either modeling the diffusivity or the orientation distribution function in Diffusion-Weighted MRI datasets. In both cases, the estimated tensors have to be positive-definite since they model positive-valued functions. In this paper we present a novel unified framework for estimating positive-definite tensors of any order, in contrast to the existing methods in literature, which are either order-specific or fail to handle the positive-definite property. The proposed framework employs a homogeneous polynomial parametrization that covers the full space of any order positive-definite tensors and explicitly imposes the positive-definite constraint on the estimated tensors. We show that this parametrization leads to a linear system that is solved using the non-negative least squares technique. The framework is demonstrated using synthetic and real data from an excised rat hippocampus.
Public Health Ethics: Mapping the Terrain

, 30 (2002): 170 –178.© 2002 by the American Society of Law, Medicine & Ethics.ublic health ethics, like the field of public health itaddresses, traditionally has focused more on practiceand particular cases than on theory, with the resultthat some concepts, methods, and boundaries remain largelyundefined. This paper attempts to provide a rough concep-tual map of the terrain of public health ethics. We begin bybriefly defining public health and identifying general fea-tures of the field that are particularly relevant for a discussionof public health ethics.Public health is primarily concerned with the health ofthe entire population, rather than the health of individuals.Its features include an emphasis on the promotion of healthand the prevention of disease and disability; the collectionand use of epidemiological data, population surveillance,and other forms of empirical quantitative assessment; a rec-ognition of the multidimensional nature of the determinantsof health; and a focus on the complex interactions of manyfactors — biological, behavioral, social, and environmental— in developing effective interventions.How can we distinguish public health from medicine?While medicine focuses on the treatment and cure of indi-vidual patients, public health aims to understand andameliorate the causes of disease and disability in a popula-tion. In addition, whereas the physician-patient relationshipis at the center of medicine, public health involves interac-tions and relationships among many professionals andmembers of the community as well as agencies of govern-ment in the development, implementation, and assessmentof interventions. From this starting point, we can suggestthat public health systems consist of all the people and ac-tions, including laws, policies, practices, and activities, thathave the primary purpose of protecting and improving thehealth of the public.
A Review of Common Congenital Anomalies of the Kidneys and Urinary Tract: From Antenatal Diagnosis to Postnatal Follow-up

Anomalies of the fetal kidneys and urinary tract are one of the most common groups of structural abnormalities discovered on routine antenatal imaging. In select cases, these anomalies represent serious medical conditions that can have varying consequences, from recurrent urinary tract infections to renal scarring and even childhood end stage renal disease. It is therefore important to differentiate which findings on antenatal ultrasound will require further evaluation and possible postnatal treatment. The finding of any urogenital abnormality warrants a detailed ultrasound to evaluate both for additional urologic abnormalities as well as for other structural anomalies. This review will focus on the antenatal diagnosis and postnatal management of several of the most common congenital anomalies of the kidney and urinary tract, as well as some of the more controversial aspects of diagnosis and follow-up in these conditions. In addition, the importance of a cooperative team approach in the care of these patients is emphasized. Often recommendations for surveillance and treatment will be individualized based upon the presumptive antenatal diagnosis. Therefore, it is critical to maintain communication between practitioners who diagnose prenatally, those who will make decisions on surveillance and treatment in the postnatal period, and our patients.
"I didn't do it:" Responsibility biases in open and closed groups.

Group members often take more responsibility for the group’s outcomes than others give to them. Extending evidence that egocentrism can be muted when group members are individuated (the “unpacking effect”), the authors predicted that members of open groups would be less egocentric than members of closed groups. In open groups, the possibility of membership fluctuation reduces collectiveness, breaking the group into individuals, which in turn lessens egocentrism. The authors tested these predictions in a study of groups of students working on a task relevant to their academic success. Members claimed more personal responsibility when they worked in closed groups relative to open groups (egocentrism), and lack of cohesion mediated the open- versus closed-group link to responsibility allocations. Moreover, members of open groups did not take more responsibility after a success than a failure, whereas those in closed, successful groups claimed more credit than members of failure groups (self-serving bias). The discussion suggests that open groups, although often thought to create conflict as members compete, may contribute to a reduction in both egocentrism and self-serving responsibility allocations.
Electromagnetic Pulses Produced by Bouncing-Wave-Type Lightning Discharges

Based on experimental evidence of multiple reflections and modeling, we infer that the so-called compact intracloud lightning discharge (CID) is essentially a bouncing-wave phenomenon. Some tens of reflections may occur at both radiating-channel ends. The reflections have little influence on the overall CID electric field signature (narrow bipolar pulse (NBP) waveform), but are responsible for its fine structure, ldquonoisinessrdquo of d E/dt waveforms, and accompanying HF-VHF radiation bursts.
Type 1 Immunity Provides Optimal Protection against Both Mucosal and Systemic Trypanosoma cruzi Challenges

Chagas' disease results from infection with Trypanosoma cruzi, a protozoan parasite that establishes systemic intracellular infection after mucosal invasion. We hypothesized that ideal vaccines for mucosally invasive, intracellular pathogens like T. cruzi should induce mucosal type 2 immunity for optimal induction of protective secretory immunoglobulin A (IgA) and systemic type 1 immunity protective against intracellular replication. However, differential mucosal and systemic immune memory could be difficult to induce because of reciprocal inhibitory actions between type 1 and type 2 responses. To test our hypotheses, we investigated the protective effects of type 1 and type 2 biased vaccines against mucosal and systemic T. cruzi challenges. Intranasal vaccinations were given with recombinant interleukin-12 (IL-12)- and IL-4-neutralizing antibody (Ab) for type 1 immune bias, or recombinant IL-4 and gamma interferon-neutralizing Ab for type 2 immune bias. Cytokine RNA and protein studies confirmed that highly polarized memory immune responses were induced by our vaccination protocols. Survival after virulent subcutaneous T. cruzi challenge was used to assess systemic protection. Mucosal protection was assessed by measuring the relative inhibition of parasite replication in mucosal tissues early after oral T. cruzi challenge, using both PCR and quantitative culture techniques. As expected, only type 1 responses protected against systemic challenges (P < 0.01). However, contrary to our original hypothesis, type 1 responses optimally protected against mucosal challenges as well (P < 0.05). Type 1 and type 2 biased vaccines induced similar secretory IgA responses. We conclude that future vaccines for T. cruzi and possibly other mucosally invasive, intracellular pathogens should induce both mucosal and systemic type 1 immunity.