cssi/SciSciGPT-SciSciNet huggingface dataset:
Magnetic phase diagram of an extended J 1 − J 2 model on a modulated square lattice and its implications for the antiferromagnetic phase of K y Fe x Se 2

Motivated by the experimentally observed $\sqrt{5}\ifmmode\times\else\texttimes\fi{}\sqrt{5}$ iron vacancy order and a block-spin antiferromagnetic phase with large magnetic moment in ${\mathrm{K}}_{0.8}{\mathrm{Fe}}_{1.6}{\mathrm{Se}}_{2}$, we study the magnetic phase diagram of an extended ${J}_{1}\ensuremath{-}{J}_{2}$ model on a $\frac{1}{5}$-depleted square lattice with $\sqrt{5}\ifmmode\times\else\texttimes\fi{}\sqrt{5}$ vacancy order, using a classical Monte Carlo analysis. The magnetic phase diagram involves various antiferromagnetically ordered phases, and most of them have higher-order commensuration. We find that the experimentally relevant block-spin state occupies a significant portion of the phase diagram, and we discuss the spin dynamics of this phase using a linear spin-wave analysis. By comparing the calculated magnetization with the experimental values of magnetic moment, we determine the physical parameter regimes corresponding to the block-spin antiferromagnetic phase. Based on our spin-wave calculations in different parameter regimes, we show how spin-wave degeneracy along the high-symmetry directions of the magnetic Brillouin zone can provide information regarding the underlying exchange couplings. We have also analyzed the magnetic phase diagram of a ${J}_{1}\ensuremath{-}{J}_{2}$ model on two different modulated square lattices relevant to ${\mathrm{K}}_{y}{\mathrm{Fe}}_{1.5}{\mathrm{Se}}_{2}$, which respectively exhibit $\frac{1}{4}$-depleted $2\ifmmode\times\else\texttimes\fi{}2$ and $4\ifmmode\times\else\texttimes\fi{}2$ vacancy ordering.
Tuning of Antigen Sensitivity by T Cell Receptor-Dependent Negative Feedback Controls T Cell Effector Function in Inflamed Tissues

Activated T cells must mediate effector responses sufficiently to clear pathogens while avoiding excessive tissue damage. Here we have combined dynamic intravital microscopy with ex vivo assessments of T cell cytokine responses to generate a detailed spatiotemporal picture of CD4(+) T cell effector regulation in the skin. In response to antigen, effector T cells arrested transiently on antigen-presenting cells, briefly producing cytokine and then resuming migration. Antigen recognition led to upregulation of the programmed death-1 (PD-1) glycoprotein by T cells and blocking its canonical ligand, programmed death-ligand 1 (PD-L1), lengthened the duration of migration arrest and cytokine production, showing that PD-1 interaction with PD-L1 is a major negative feedback regulator of antigen responsiveness. We speculate that the immune system employs T cell recruitment, transient activation, and rapid desensitization to allow the T cell response to rapidly adjust to changes in antigen presentation and minimize collateral injury to the host.
Working Memory in Attention Deficit/Hyperactivity Disorder is Characterized by a Lack of Specialization of Brain Function

Working memory impairments are frequent in Attention Deficit/Hyperactivity Disorder (ADHD) and create problems along numerous functional dimensions. The present study utilized the Visual Serial Addition Task (VSAT) and functional magnetic resonance imaging (fMRI) to explore working memory processes in thirteen typically developing (TD) control and thirteen children with ADHD, Combined type. Analysis of Variance (ANOVA) was used to examine both main effects and interactions. Working memory-specific activity was found in TD children in the bilateral prefrontal cortex. In contrast the within-group map in ADHD did not reveal any working-memory specific regions. Main effects of condition suggested that the right middle frontal gyrus (BA6) and the right precuneus were engaged by both groups during working memory processing. Group differences were driven by significantly greater, non-working memory-specific, activation in the ADHD relative to TD group in the bilateral insula extending into basal ganglia and the medial prefrontal cortex. A region of interest analysis revealed a region in left middle frontal gyrus that was more active during working memory in TD controls. Thus, only the TD group appeared to display working memory-modulated brain activation. In conclusion, children with ADHD demonstrated reduced working memory task specific brain activation in comparison to their peers. These data suggest inefficiency in functional recruitment by individuals with ADHD represented by a poor match between task demands and appropriate levels of brain activity.
Phase metastability and supercooled metastable state of diundecanoylphosphatidylethanolamine bilayers.

Abstract Aqueous dispersons of l -α-phosphatidylethanolamine (PE) with identical saturated acyl chains are known to exhibit gel-state metastability. It is also known that the metastability in PE becomes more pronounced with decreasing acyl chain-length. In an attempt to study the metastable phase behavior of PE, we have synthesized diundecanoylphosphatidylethanolamine (diC11PE) and examined its polymorphic phase behavior. A single endothermic transition at 38° C is detected between 10 and 55° C by DSC for the nonheated sample of diC11PE in excess water. An immediate second heating scan done after cooling slowly of the same sample from the liquid-crystalline state shows a smaller endothermic transition at a lower temperature, 18°C. However, the high-temperature transition at 38° C can be detected, if the sample which has been heated above 38° C is quench cooled from the liquid-crystalline to a temperature between 18 and 38° C. Furthermore, two endothermic transitions at 18 and 38° C and an exothermic transition at 19° C are recorded for diC11PE after quench supercooling of the sample from the liquid-crystalline state to an appropriate temperature below 10° C. The gel-state metastability of diC11PE can be most appropriately explained in terms of changes in interbilayer headgroup-headgroup interactions. It is suggested that the kinetically trapped supercooled metastable state may be a multilamellar structure with melted acyl chains but with strong interbilayer headgroup-headgroup interactions.
An extention of the Kac-Rice formula for the average number of zeros of random algebraic polynomials

We extend the Kac-Rice formula for the expected number of real zeros of random algebraic polynomials on R1 with R1-valued random coefficients to complex zeros of random algebraic polynomials on C1 with C1-valued random coefficients. Our method directly extends to multivariable cases
Issues in nanophotonics: coupling and phase in resonant tunneling

Modern Nano electronics involves the use of heterojunctions in forming energy steps based on band-edge alignments in effecting quantum confinements. When the electron meanfree- path exceeds couple of periods, man-made quantum states appeared, mimicking natural solids with sharpness determined by the degree of coherence dictated by a relatively long meanfree- path. When a single quantum well is involved, the structure is represented by resonant tunneling. This process can further be extended to 3D (3-dimension), known as QD, for quantum dot, however, thus far only few systems have been found possible, mostly involving InAs, or InN. However, the real problem lies in I/O, making contact to a single quantum dot, seems to be impractical on account of difficulties in making contacts in Nano scale regime. The issue with impedance matching, is the most important aspect for efficient devices, whether as detectors, or as generator in frequencies between THz to visible light. As size shrinks to Nano-regime, even the wavelength of IR is too large for effective coupling to the quantum dots without some sort of coupling such as the use of Fabry-Perrot mirrors, which is in fact unsuited for quantum dots, unless these dots are arranged in an array mimicking a solid with translational symmetry, which in fact defeating the purpose of going to quantum dots, except when the distribution of these quantum dots are arranged either representable by some distribution functions suitable for arriving at a meaningful average, or periodically mimicking a solid, such as the man-made superlattice, SL, originally proposed by Esaki and Tsu. [1, 2]. Interestingly Esaki and Tsu were asked to remove the reference on doping in the barrier region for increased mobility by the reviewer for the IBM’s own J. of Research and Development. We did protest to the Editor-in- Chief of the Journal to no avail! Because of this experience, it did occur to me of requiring something beyond the regular reviewing process in technical journals. Some ten years ago, I proposed to M. Henini the need to have a journal with two outlets for publications, one ‘regular’, and another as ‘special’: rejected by reviewer, but accepted by the editorial staff. For some reason, we did not get enough support then.
4'-(5'''-R-pyrimidyl)-2,2':6',2''-terpyridyl (R = H, OEt, Ph, Cl, CN) platinum(II) phenylacetylide complexes: synthesis and photophysics.

A series of new square-planar 4′-(5′′′-R-pyrimidyl)-2,2′:6′,2′′-terpyridyl platinum(II) phenylacetylide complexes (1a−5a) bearing different substituents (R = H, OEt, Ph, Cl, CN) on the pyrimidyl ring have been synthesized and characterized. The electronic absorption, photoluminescence, and triplet transient difference absorption spectra were investigated. All of the complexes exhibit broad, moderately strong absorption between 400 and 500 nm that can be tentatively assigned to the metal-to-ligand charge transfer (1MLCT) transition, possibly mixed with some ligand-to-ligand charge transfer (1LLCT) character. Photoluminescence arising from the 3MLCT state was observed both in fluid solutions at room temperature and in a rigid matrix at 77 K. The 1MLCT/1LLCT absorption bands and the 3MLCT emission bands for 1a−5a red-shift in comparison to those of the corresponding 4′-toly-2,2′:6′,2′′-terpyridyl platinum(II) phenylacetylide complex. In addition, the energies of the 1MLCT/1LLCT absorption and the 3MLCT emiss...
Modeling Count Outcomes from HIV Risk Reduction Interventions: A Comparison of Competing Statistical Models for Count Responses

Modeling count data from sexual behavioral outcomes involves many challenges, especially when the data exhibit a preponderance of zeros and overdispersion. In particular, the popular Poisson log-linear model is not appropriate for modeling such outcomes. Although alternatives exist for addressing both issues, they are not widely and effectively used in sex health research, especially in HIV prevention intervention and related studies. In this paper, we discuss how to analyze count outcomes distributed with excess of zeros and overdispersion and introduce appropriate model-fit indices for comparing the performance of competing models, using data from a real study on HIV prevention intervention. The in-depth look at these common issues arising from studies involving behavioral outcomes will promote sound statistical analyses and facilitate research in this and other related areas.
Developmental changes in the actions of phosphatase inhibitors on calcium current of rabbit heart cells

We used whole-cell voltage clamp to compare the modulation of calcium current density (I Ca, picoampere per picofarad) of freshly isolated, adult and newborn rabbit heart in response to intracellular application of microcystin and okadaic acid, both of which block phosphatase activity of phosphatase types 1 and 2A. Newborn cells showed a much larger response to the intracellular application of either microcystin or okadaic acid than did adult cells. In newborn cells, the application of microcystin produced an increase in I Ca which appeared to maximize I Ca, as shown by the rise in I Ca to levels which could be reached by application of 10 μM forskolin or by the intracellular application of 200 μM 3′,5′-cyclic adenosine monophosphate (cAMP). In adult cells, the maximal response to microcystin was considerably less than that obtainable with forskolin or cAMP. After achieving a maximal response with microcystin, the addition of forskolin increased I Ca further in adult cells but elicited no additional response in newborn cells. The treatment of cells with 0.1 μM isoproterenol, a concentration approximately equal to that required for a half-maximal response, strongly potentiated the effect of microcystin in newborn cells, but not in adult cells. We propose that newborn rabbit heart cells compared with adult rabbit heart cells have a greater level of protein phosphatase activity (perhaps combined with a somewhat greater kinase activity), a greater proportion of the protein phosphatase activity in the form of protein phosphatase type 1 (which is inhibited by isoproterenol) and a greater dependence on the inhibition of protein phosphatase as a mechanism of action of isoproterenol, compared with the increase in kinase activity on calcium channels.
Light and electron microscopic studies on the development and liberation of Janczewskia gardneri Setch. spermatia (Rhodophyta)

Abstract Janczewskia spermatia occur in conceptacles and are formed by spermatangial mother cells that originate directly from the inner conceptacular cell layer or from uniseriate filaments. Each spermatangial mother cell produces several spermatangia. Young spermatia are enclosed within an electron dense spermatangial wall and are connected to their respective mother cells by a small septal plug. Reduced chloroplasts are present in the mother cells and in some developing spermatia. As the spermatia mature, the spermatangial wall gelatinizes at the apex of the spermatangium. Subsequently or concomitantly a two-layered spermatial wall forms which ruptures the spermatangium-mother cell pit connection. Rough endoplasmic reticulum aggregates in the posterior end of the spermatium to form spermatial vesicles containing fibrillar material, whereas dictyosome vesicles contribute to the fibrillar material accumulation in later stages. Shortly before or after release from the spermatangial mother cells, the sperm...
Thinking about luck

Luck looms large in numerous different philosophical subfields. Unfortunately, work focused exclusively on the nature of luck is in short supply on the contemporary analytic scene. In his highly impressive recent book Epistemic Luck, Duncan Pritchard helps rectify this neglect by presenting a partial account of luck that he uses to illuminate various ways luck can figure in cognition. In this paper, I critically evaluate both Pritchard’s account of luck and another account to which Pritchard’s discussion draws our attention—viz., that due to Nicholas Rescher. I also assess some novel analyses of luck that incorporate plausible elements of Pritchard’s and Rescher’s accounts.
Retardation of experimental atherosclerosis in endarterectomized arteries by the administration of heparin and dextran.

In 1964 Szilagyi, Smith, and Whitney I1] reported a high recurrence of atheromas after aortoiliac endarterectomy in man, and they suggested that this process was progressive. Heparin was not used postoperatively in these patients. An analysis of aortoiliac endarterectomy at UCLA [2] suggested that recurrence was more common when heparin was not given postoperatively. even though heparin had been Used on the patients deemed more likely to have postoperative thrombosis and early failure. The postulate was made that hep;~rin given during the healing period might decrease later recurrence of atheroma in an endarterectomized segment. Barker and Barakonski [2] and Foster et 21 [3] have postulated that dextran also might protect the artery during the healing process. The incidence of stenosis in other series of endarterectomies [4] has been smaller than the 40 per cent reported by Szilagyi. Further observations [4] have suggested that about half the late occlusions after aortoiliac endartcreetomy are due to development of an occlusion at the end of the endarterectomized segment or, to progression of distal disease. Some of these may represent rough areas left at the time of endarterectomy or incompleteness of the endarterectomy. The recurrence of atheromatous disease in the endarterectomized segments remains a problem and is the subject of this discussion.
Proposing and Testing an Intellectual Capital‐Based View of the Firm

This study examines one specific aspect of the resource-based view, intellectual capital, and its three knowledge components - human, organizational, and social capital. We hypothesize that the impact of each component on financial performance is contingent upon the values of the other components, and that these leveraging effects are themselves contingent upon the industry conditions in which a business operates. Our hypotheses are supported using line-of-business survey and FDIC data (within-industry/within-geographic region) from two non-competing resource niches of the banking industry (personal and commercial banking).
An algorithm for linear least squares problems with equality and nonnegativity constraints

A new algorithm for solving a linear least-squares problem with linear constraints is presented. The constraints can be equality constraint equations and nonnegativity constraints on selected variables. This problem, while appearing to be quite special, is the core problem arising in the solution of the general linearly constrained linear least-squares problem. The reduction process of the general problem to the core problem can be done in many ways. Three such techniques are discussed. The method employed for solving the core problem is based on combining the equality constraints with differentially weighted least-squares equations to form an augmented least-squares system. This weighted least-squares system is solved with nonnegativity constraints on selected variables. Seven small examples, including a constrained least-squares curve fitting example, are presented. A reference to user instructions for subprograms to compute solutions of constrained least-squares problems is included. 3 figures, 9 tables.
Sensor Alert Verification for Incident Operational Response (SAVIOR)

We are developing a decision support architecture for chemical sensing networks, with the goal of improving their capability by interpreting alerts in the context of other available information. Most simply, health and status metrics derived from sensor data might indicate that false alerts are more than usually likely. In principle, however contextual information can come from a vast number of sources, including field or laboratory sensor calibration data and prior characterization of potential interferants, as well as site-specific data such as the results of environmental samples, meteorological data, historical alert incidence, and observations from on-site observers. To accommodate this diversity of data sources, we apply Bayesian network techniques that are commonly employed for information management in many expert systems, including for automated medical diagnosis and target identification in various military applications.
Simian homologues of human herpesvirus 8

γ–Herpesviruses can be found in most primates including Old World an New World monkeys. The γ– herpesvirinae are grouped into two classes: lymphocryptoviruses (γ1) and rhadinoviruses (γ2). The lymphocryptoviruses include Epstein–Barr virus, lymphocryptovirus of rhesus monkeys, and Herpesvirus papio of baboons. Rhadinoviruses that infect New World monkeys include Herpesvirus saimiri , whose natural host is the squirrel monkey, and Herpesvirus ateles , which infects spider monkeys. Rhadinoviruses that infect hominoids and Old World monkeys include Kaposi's sarcoma–associated herpesvirus, also known as HHV–8, and rhesus monkey rhadinovirus.
Understanding Dynamic Denial of Service Attacks in Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), Denial of Service (DoS) attacks not only consume the scarce system resources, such as bandwidth, battery energy, or CPU cycles, but also isolate legitimate users from a network. Therefore, DoS attacks may impact the network connectivity seriously and may further undermine the networking functions, such as control and data message delivery. In this paper, we will present a deep insight into DoS attacks and their impacts on MANETs. First, we analyze the node isolation problem resulting from DoS attacks and derive the probability of node isolation, which shows that the DoS attack exploiting fraudulent routing messages, such as BlackHole attack, impacts the connectivity much severer than other attacks. Second, we notice that the node mobility and potential attack propagation have hardly been considered in the previous DoS attack studies; therefore, we introduce a dynamic DoS attack in this paper. The dynamic DoS attack is characterized in exploiting the node mobility, dynamic power control, and compromised nodes to spread new DoS attacks dynamically. Further, we provide an analytical study on the properties of this new DoS attack, and explain its potential devastating impact on the connectivity of MANETs.
God, Benefactor and Patron: The Major Cultural Model for Interpreting the Deity in Greco-Roman Antiquity:

This study contributes to a renewed interest in the Christian Deity by employing the cultural model of benefactor-client relations. What is fresh here is an enlarged model of this pattern of social relations and fresh, apt, and plentiful illustrations of it in antiquity. The patron-client model is expanded by concern for types of reciprocity and classification of what is exchanged. Typical titles of God- as-benefactor are examined in light of media of exchange, especially power, knowledge, and material benefaction. Then several leading questions are asked: Why does God indeed give benefaction? What kind of reciprocity is in view? What kind of debt is incurred? Finally, what do clients return to God? Elites in antiquity state that God wants nothing and needs nothing. Yet mortals have offered sacrifice, a form of inducement, which practice Christians and philosophers rejected.
Measuring of a three-dimensional surface by use of a spatial distance computation.

The correspondence problem of two captured images, which are obtained by projecting a structured light on the measuring surface, are explored for when three-dimensional information of a given surface is needed. In our system the constraint that codifies the pattern projected on the surface has been simplified by using a random speckle pattern, thus the correspondence problem is reduced to local matching between two captured images and solved by a spatial distance computation technique. The performance of our approach, which includes a disparity error analysis, a search range suggestion, and a disparity gradient limit, are investigated and discussed. Some parameters, such as percentile constraint, sampling interval, and subpixel compensation proper for use in this approach are suggested. Experiments have shown the feasibility of the proposed method.
Dynamic generation of accident progression event trees

Currently, the development and analysis of accident progression event trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. A software tool is presented for automated APET generation using the concept of dynamic event trees. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. While the software tool could be applied to any systems analysis code, the MELCOR code is used for this illustration. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a pressurized water reactor.
Communicating How Water Works: Results From a Community Water Education Program

Based on feedback from attendees at an environmental summit who requested information about regional water sources, a team comprised of a local nonprofit, a state university, and a cooperative extension office created a community water education program. Undergraduate student interns worked with the author to develop a 20-minute science-based presentation that was delivered in 14 different venues in a three-county region of northwestern North Carolina. Following each presentation there was a discussion session that highlighted questions about how water works and community concerns about water availability and management. Program evaluations reflect that people believed they better understood the science related to water quantity and that the key messages in the program were important to their communities.
Effect of pH on subunit association and heat protection of soybean α-galactosidase

Soybeans contain the enzyme alpha-galactosidase, which hydrolyzes alpha-1, 6 linkages in stachyose and raffinose to give sucrose and galactose. We have found that galactose, a competitive product inhibitor of alpha-galactosidase, strongly promotes the heat stability of the tetrameric form of the enzyme at pH 4.0 and at temperatures of up to 70 degrees C for 60 min. Stachyose and raffinose also protect alpha-galactosidase from denaturation at pH 4.0 although to a lesser extent. Glucose and mannose have little effect. At pH 7.0 the enzyme is a monomer, and galactose has no effect on the heat stability of the enzyme. In the absence of heat protection of the enzyme by added sugars, a series deactivation mechanism was found to describe the deactivation data. In comparison, a unimolecular, non-first order deactivation model applies at pH 4.0, where heat protection effects were observed. At a temperature above 60 degrees C, simple deactivation is a suitable model. The results suggest that alpha-galactosidase conformation and heat stability are directly related.
Ultraviolet Submersible Spectroradiometer

An increase in the incidence of solar ultraviolet radiation upon oceans and lakes, as a consequence of anthropogenic diminishing of the ozone in the stratosphere, might well have a significant effect upon primary producers and other aquatic organisms in these waters. Existing data were inadequate for accurately estimating the penetration of biologically effective dosages of present and potential future levels of UV irradiance into various natural waters. An underwater spectroradiometer, designed specifically to measure spectral irradiance in the middle ultraviolet (MUV, 280-340 nm), has been designed, constructed and used to obtain ecologically important data.
Sealants for solid oxide fuel cells

Abstract One of the major challenges for implementation of solid oxide fuel cells (SOFCs) is the development of suitable sealant materials to separate the air and fuel. Several approaches have been used to achieve the necessary adherence, mechanical integrity and stability, including both rigid seals (no applied load during operation) and compressive seals (load applied to seal during operation). The most common approach is to use rigid glass or glass–ceramic seals, the properties of which can be tailored specifically for use in SOFCs through variation of the glass composition. However, these ceramic materials are inherently brittle, so metallic, metallic–ceramic and ceramic–ceramic composite seals, in both the rigid and compressive configurations, have been developed. The use of multiphase seals allows for improvement in factors, such as wettability, compliance at interfaces and strain relief, to improve the gas-tightness and stability of the seal. In this paper, the different approaches for developing SOFC sealants are reviewed.
Active fiber composite continuous sensors

This paper examines the use of continuous sensors to detect damage in composite materials. Continuous sensors contain multiple interconnected sensor nodes that can be integrated into an artificial neural system as an array of sensor nerves. The advantage of this passive health monitoring approach is that the sensor system is highly distributed and uses parallel processing allowing large structures to be monitored for damage using a small number of channels of data acquisition. In the paper, the continuous sensor system is modeled and simulated by solving the elastic response of a plate and the coupled piezoelectric constitutive equations. The model and simulation allow the sensor system to be optimized for a particular material and plate size. The simulation predicts that acoustic waves representative of damage growth can be detected anywhere in the plate using a simple artificial neural system. To improve the sensitivity of the continuous sensor, unidirectional active fiber composite sensors were built from piezoceramic ribbon preforms. Manufacturing of the active fiber composite sensors is also discussed in the paper. The continuous sensors were evaluated in a realistic test to show their ability detect acoustic emissions caused by damage to a composite material. The sensors were mounted on narrow glass fiber plates and tested to failure in a mechanical test machine. Results from the experiments are presented.
Functional consequences of the repeated administration of Δ9-tetrahydrocannabinol in the rat

Abstract The repeated administration of Δ9-tetrahydrocannabinol (THC) results in tolerance to many of its behavioral and physiological effects. It also produces changes in the functionality of cannabinoid receptors. What is not completely understood is how these cellular events translate into the behavioral and physiological changes that are associated with repeated cannabinoid agonist treatment. The purpose of these studies was to determine the development of changes in the patterns of functional activity, as measured by the 2-[14C]deoxyglucose method (2DG), associated with repeated THC exposure. Male Sprague–Dawley rats (n=4–5) were administered THC (vehicle or 10 mg/kg, intraperitoneally), daily for 7 or 21 days. Fifteen minutes following the final THC treatment the 2DG procedure was initiated. In separate sets of rats similarly treated with THC, locomotor activity and core body temperature were measured at corresponding time points in order to establish the behavioral profile of repeated THC administration. The acute administration of THC following 7 or 21 days of drug exposure resulted in a significant attenuation of changes in rates of glucose utilization throughout the majority of brain regions analyzed when compared to the large global decreases observed following a single administration of THC. After 7 and 21 days of treatment, cerebral metabolic rates were no longer different from vehicle-treated controls in most cortical, thalamic and basal ganglia regions. This attenuation closely paralleled the development of tolerance to the effects of THC on locomotor activity and core body temperature. However, glucose utilization remained altered in the nucleus accumbens, mediodorsal thalamus, basolateral amygdala, portions of the hippocampus and median raphe. These data suggest that the development of tolerance to the cerebral metabolic effects of THC is regionally specific and temporally distinct. The persistence of effects in limbic areas as well as portions of the hippocampal complex, however, suggests that processes such as stress, reward, and aspects of memory mediated by these brain regions may continue to be affected by THC even after prolonged THC exposure.
Future needs for fixed and removable partial dentures in the United States

Abstract Statement of Problem. Because of the decline in missing teeth among most adults, prosthodontic advanced training programs are concerned about the need for prosthodontics in the future. Purpose. An analysis was conducted to project the unmet need for fixed and removable partial dentures in the years 2005, 2010, and 2020. Material and Methods. Unmet need was calculated as follows: Total need equals the number of persons in each age cohort multiplied by the percentage who need a fixed or removable partial denture multiplied by the average procedure time required to provide the service. Total unmet need then equals total need minus the annual supply of prosthodontic services delivered by prosthodontists and general practitioners. Results. Projected results indicate that total unmet need will increase from 488 million hours in 2005 to 517 million hours in 2010 and to 560 million hours in 2020. Conclusion. The significance of the results is that unmet prosthodontic need will increase and exceed the supply of services for the foreseeable 20-year future. Practicing dentists will find that a sizable minority of the population will continue to need fixed and removable partial denture services. (J Prosthet Dent 2002;87:9-14.)
Redox and Lewis Acid Reactivity of Unsaturated OsII

A synthesis of [(PNP)OsI] {PNP = (tBu 2 PCH 2 SiMe 2 ) 2 N} permits evaluation of its reactivity, both Lewis acidity and reducing power (i.e., ability to be oxidized). It binds two molecules of PhCN, into trans sites, but only one of ethylene, and, upon binding of one N 2 , there is heterolytic splitting of one tBu C-H bond to put the proton on amide N and the carbon on Os, leaving divalent metal in [{PN(H)P*}Os(N 2 )(I)]. Two moles of H 2 add, forming [{PN(H)P}OsH(H 2 )I], via H-H bond heterolysis. Thermolysis of [(PNP)OsI] gives the product of adding a tBu methyl C-H bond across the Os/N bond, and also net dehydrogenation of this intermediate, forming a carbene complex; the released H 2 forms [(PNP)OsH 2 I], and the chemistry of [(PNP)Os] hydridohalides is described. Reaction with O 2 occurs with no detectable intermediate, to completely split the O=O bond, and form trans-[(PNP)Os(O) 2 I], a product of four electron redox change. Attempted two electron oxidation by oxygen atom transfer with pyridine N-oxide or Me 3 NO or N 2 O surprisingly effect transposition of N from its silyl substituents onto the metal, and replace N by 0, forming a nitride complex of a bis(silyl ether, phosphane) chelate whose oxygen fails to bind to Os. The product is thus four-coordinate, tetrahedral [(POP)Os(N)I], with an Os/N triple bond.
Hepatitis B vaccination in pregnancy-factors associated with immunity in subsequent pregnancy

WITH IMMUNITY IN SUBSEQUENT PREGNANCY CHARLES INGARDIA, MARY MORGAN, DEBORAH FELDMAN, RENEE BOBROWSKI, Hartford Hospital, Maternal Fetal Medicine, Hartford, CT Hartford Hospital, Hartford, CT OBJECTIVE: To determine the efficacy of hepatitis B vaccination during pregnancy on the rate of hepatitis B seroimmunity in subsequent pregnancy. STUDY DESIGN: A retrospective study was conducted on 187 women who received hepatitis B vaccination (Engerix-B) during pregnancy who were tested for hepatitis B surface antibody (HbsAb) in the subsequent pregnancy. All women had begun the series of the three vaccinations (0, 1, and 6 mo) during the previous pregnancy. Patients were grouped by number of vaccinations given during that pregnancy (1, 2, or 3), vaccination to re-screen interval ( <24 mo ,$24 mo), maternal age at first vaccination ( <25 yr, $25 yr), body mass index (BMI) ( < 35, $35), and smoking history. Chi-square with Fisher exact test were used for statistical analysis.. RESULTS: Immunity was demonstrated in 61% ( 114/187) of gravidas in their subsequent pregnancy. Patients who received 3 vaccinations, 2 vaccinations, and 1 vaccination had seropositive rates of 85% (46/54), 49% (47/95), and 63% (24/38), respectively (NS). There was no difference in seroimmunity comparing vaccination to re-screen interval groups: ( <24 mo61% vs$24 mo–61%) or in patients with smoking history (65%) vs nonsmokers ( 55%). Maternal age at 1st vaccine <25 yrs was associated with higher degree of seroimmunity compared to those $25 yrs ( 65% vs 47%, P = .04). Although excessive obesity (BMI $35) was associated with lower rates of seroimmunity compared to those women with BMI < 35 ( 38% vs 59%), the difference was not significant ( P = .14) CONCLUSION: Women vaccinated during the previous pregnancy continue to demonstrate seroimmunity in their subsequent pregnancy. Younger maternal age at vaccination is associated with significantly higher rates of seroimmunity.
Nurse Aides’ Reports of Resident Abuse in Nursing Homes

Verbal, physical, psychological, caregiving, medication, material, and sexual abuse perpetrated by staff are examined. Information came from nurse aides included in the Pennsylvania nurse aide regi...
Crucible Selection in AlN Bulk Crystal Growth

Growth of AIN bulk single crystals by sublimation of AIN powder was carried out in a resistively heated reactor at temperatures up to 2300°C. A variety of crucible materials, such as BN, W, Ta, Re, ZrO2, TaN, and TaC, were evaluated. Our studies have shown that the morphology of crystals grown by spontaneous nucleation strongly depends on the growth temperature and contamination in the reactor. Crucible selection had a profound effect on contamination in the crystal growth environment, thus influencing nucleation, coalescence, and crystal morphology. Spontaneously grown single crystals up to 15 mm in size were characterized by x-ray diffraction (XRD), x-ray topography (XRT), glow discharge mass spectrometry (GDMS), and secondary ion mass spectrometry (SIMS). Average dislocation densities were on the order of 103 cm−3, with extended areas virtually dislocation-free, while high-resolution XRD showed rocking curves as narrow as 7 arcsec.
Methanogenesis-induced pH–Eh shifts drives aqueous metal(loid) mobility in sulfide mineral systems under CO2 enriched conditions

Abstract To better understand the role of CO2-utilizing processes in determining geochemical outcomes in CO2-impacted, reduced subsurface environments; we studied hydrogenotrophic methanogenesis (a key process across a range of subsurface systems) and associated changes in CO2–CH4, pH–Eh and metal(loid) dynamics in CO2-enriched pyrite-, arsenopyrite- and galena-containing batch reactors. Hydrogenotrophic methanogenesis proceeded via two first-order, microbially-mediated steps. The first involved microbially-enhanced gas-to-solution transfer of CO2 with a rate constant of 0.95 ± 0.20 d−1 (compared to 0.17 ± 0.34 d−1 in non-methanogenic reactors). The second step involved the pseudo-first order reduction of HCO3−-to-CH4 with a rate constant of 0.46 ± 0.10 d−1. Bicarbonate reduction accounted for 76% of the CO2–C removed from the reactors’ headspace and triggered a decrease in Eh (−0.215 to −0.332 V) and an increase in pH (6.93 to 8.03). No significant effect on dissolved Pb (or its release from galena) was observed but dissolved Fe decreased and dissolved As increased during methanogenesis. Changes in dissolved Fe and As were proportional to methanogenesis-induced pH–Eh shifts and attributable to an initial CO2-induced release of As and Fe from arsenopyrite (and Fe from pyrite) with subsequent methanogenesis-induced increase in pH and electron activity triggering the precipitation of Fe, as amorphous FeCO3·6H2O. In addition to the role of methanogenesis in enhancing, (1) aqueous dissolution of CO2, (2) CO2 to carbonate mineralization and (3) immobilization of some metals, our findings suggested that due to its occurrence after CO2 dissolution and before carbonate precipitation, extensive HCO3−-to-CH4 reduction would lower solubility- and mineral-trapping of CO2. Such considerations are central to assessments of how CO2-utilizing processes may alter long-term outcomes at geologic storage sites.
The reliability of semiconductor RAM memories with on-chip error-correction coding

The mean lifetimes are studied of semiconductor memories that have been encoded with an on-chip single error-correcting code along each row of memory cells. Specifically, the effects of single-cell soft errors and various hardware failures (single-cell, row, column, row-column, and entire chip) in the presence of soft-error scrubbing are examined. An expression is presented for computing the mean time to failure of such memories in the presence of these types of errors using the Poisson approximation; the expression has been confirmed experimentally to accurately model the mean time to failure of memories protected by single error-correcting codes. These analyses will enable the system designer to accurately assess the improvement in mean time to failure (MTTF) achieved by the use of error-control coding. >
Perceptually-Based Depth-Ordering Enhancement for Direct Volume Rendering

Visualizing complex volume data usually renders selected parts of the volume semitransparently to see inner structures of the volume or provide a context. This presents a challenge for volume rendering methods to produce images with unambiguous depth-ordering perception. Existing methods use visual cues such as halos and shadows to enhance depth perception. Along with other limitations, these methods introduce redundant information and require additional overhead. This paper presents a new approach to enhancing depth-ordering perception of volume rendered images without using additional visual cues. We set up an energy function based on quantitative perception models to measure the quality of the images in terms of the effectiveness of depth-ordering and transparency perception as well as the faithfulness of the information revealed. Guided by the function, we use a conjugate gradient method to iteratively and judiciously enhance the results. Our method can complement existing systems for enhancing volume rendering results. The experimental results demonstrate the usefulness and effectiveness of our approach.
Sanger, Margaret Higgins (1879–1966)

Margaret Sanger was an early twentieth-century activist for birth control, sex education, and women's reproductive freedom. Sanger's almost sixty-year campaign for birth control redefined women's sex roles by separating sex from reproduction and encouraged women to understand their bodies and to demand sexual satisfaction in marriage. Keywords: birth control; feminism; reproductive rights; sex education
Fault-Intrusion Tolerant Techniques in Wireless Sensor Networks

Wireless sensor networks (WSN) consist of a large number of tiny sensor devices that have limited power and limited sensing, computation, and wireless communications capabilities. Sensor nodes usually operate in unattended and even harsh environments, and as a result, sensor nodes are prone to failures and are vulnerable to malicious attacks. Therefore, for reliable and secure computation and communication in WSN, fault tolerance and intrusion tolerance become two essential attributes that should be designed into WSN. In this paper, we study state-of-the-art fault tolerance and intrusion tolerance techniques for WSN and propose a new fault-intrusion tolerant routing mechanism called MVMP (multi-version multi-path) for WSN that will support highly reliable and secure sensor networks. Follow-up work on the MVMP to be carried out in the near future is also discussed.
Characterization of the Genomic Structure of the Human Vitamin C Transporter SVCT1 (SLC23A2)

Vitamin C (L-ascorbic acid), a critical cofactor for intracellular enzymatic reactions, functions as a scavenger of free oxygen radicals and is an essential micronutrient. Vitamin C is actively transported into cells by one of two closely related sodium-dependent transporters, SVCT1 or SVCT2. In this paper, we report the complete sequencing and gene structure of SLC23A2, the gene encoding SVCT1. The1797-bp cDNA sequence (open reading frame) of the SLC23A2 gene was derived from a compact genomic sequence of 7966 bp [translation initiation codon (ATG) to poly A tail], which is divided into 14 exons. Furthermore, repetitive or masked elements constituted 17.98% of the gene; there were 4 Alu sequences and 5 MIR (Mammalian Interspersed Repetitive element) sequences. A search for common variants in SLC23A2, using current bioinformatic tools and direct resequencing of control populations, failed to identify common single nucleotide polymorphisms. The start of transcription was mapped to a position -47 relative to the ATG; the immediate 5' sequence was determined and analyzed for possible consensus binding sites for known transcription factors. Our findings will serve as the foundation for investigation of the regulation and expression of the tissue-specific sodium-dependent vitamin C transporter, SLC23A2.
Sulforaphane- and phenethyl isothiocyanate-induced inhibition of aflatoxin B1-mediated genotoxicity in human hepatocytes: role of GSTM1 genotype and CYP3A4 gene expression.

Primary cultures of human hepatocytes were used to investigate whether the dietary isothiocyanates, sulforaphane (SFN), and phenethyl isothiocyanate (PEITC) can reduce DNA adduct formation of the hepatocarcinogen aflatoxin B1 (AFB). Following 48 h of pretreatment, 10 and 50μM SFN greatly decreased AFB-DNA adduct levels, whereas 25μM PEITC decreased AFB-DNA adducts in some but not all hepatocyte preparations. Microarray and quantitative reverse transcriptase (RT)-PCR analyses of gene expression in SFN and PEITC-treated hepatocytes demonstrated that SFN greatly decreased cytochrome P450 (CYP) 3A4 mRNA but did not induce the expression of either glutathione S-transferase (GST) M1 or GSTT1. The protective effects of SFN required pretreatment; cotreatment of hepatocytes with SFN and AFB in the absence of pretreatment had no effect on AFB-DNA adduct formation. When AFB-DNA adduct formation was evaluated by GST genotype, the presence of one or two functional alleles of GSTM1 was associated with a 75% reduction in AFB-DNA adducts, compared with GSTM1 null. In conclusion, these results demonstrate that the inhibition of AFB-DNA adduct formation by SFN is dependent on changes in gene expression rather than direct inhibition of catalytic activity. Transcriptional repression of genes involved in AFB bioactivation (CYP3A4 and CYP1A2), but not transcriptional activation of GSTs, may be responsible for the protective effects of SFN. Although GSTM1 expression was not induced by SFN, the presence of a functional GSTM1 allele can afford substantial protection against AFB-DNA damage in human liver. The downregulation of CYP3A4 by SFN may have important implications for drug interactions.
THz frequency up-conversion in transverse configuration by exploiting polariton resonance: From complete photon conversion to single-photon detection

Transversely-propagating THz radiation can be up-converted to an optical wave propagating in the waveguide. Complete photon conversion and single-photon detection can be reached.
Thermal Analysis of the ALR8(SI) Plutonium Storage Container

Asa result oftheend of the cold war, atleast11,000, and possibly up to 20,000, plutonium pits are projected to be stored in temporary storage facilities in the United States for up to 50 years. The storage container, the ALR8 (SI), mustbeinvestigatedforqualityandlongevityrequirements.AsapartofvalidatingtheU.S.DepartmentofEnergy’ s quality requirements, a computer model was developed and validated to predict the temperature distribution within both the stored components and the internal structure of the ALR8 (SI) container to analyze the thermal performance of the container. Experimental data were obtained and served as a comparison for examining the validity of the numerical model. The thermal response of the ALR8 (SI) under normal storage conditions was investigated experimentally. Results were obtained for different values of heat generation rate (15, 20, 25, and 30 W), outside container temperature (20, 25, and 30 ±C), and different backe ll gases (air, argon, and helium ). A e nite element model consisting of a thermal and a e ow domain was created and solved simultaneously using SDRC I-DEAS Master Series 6. Solutions were obtained for most of the experiments performed. The predicted temperaturedistributionmatchedquitewellinmagnitudewiththeexperimentaldata.Formostlocations,predicted temperatures deviated less than 2 ±C from the experimental temperatures, whereas the maximum deviation was around4±C. In most cases, the maximum-recorded temperature exceeded the quality limit of 60 ±C. A theoretical study of the heat transfer mechanisms showed either conduction through the backe ll gas or natural convection as theprimary mode of heattransfer, depending on the backe llgas.In an attempt to reducethe interiortemperatures of the ALR8(SI), a modie cation to one of the ALR8 (SI) components was made in the numerical model to enhance heat transfer. Solutions of this modie ed container predicted signie cantly lower temperatures of the interior.