cssi/SciSciGPT-SciSciNet huggingface dataset:
n − n and n − p Scattering Lengths and Charge Independence

The degree of charge-independence violation for the low-energy nucleon-nucleon system is studied on the basis of a semiphenomenological meson theory. The difference between the singlet $n\ensuremath{-}p$ and $n\ensuremath{-}n$ scattering lengths induced by the ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{-}{\ensuremath{\pi}}^{0}$ and ${\ensuremath{\rho}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{-}{\ensuremath{\rho}}^{0}$ ($\ensuremath{\Delta}m$) electromagnetic mass splittings is investigated for the one-pion-, two-pion-, and $\ensuremath{\rho}$-exchange potentials. A charge-independent boundary condition is used to replace the short-range behavior. It is found that approximately 60% of the measured difference between the scattering lengths can be accounted for by the one-pion and two-pion potentials with charge-independent pseudoscalar coupling. The calculated results are sensitive to parameters of the $\ensuremath{\rho}$-exchange potential, such as $\ensuremath{\Delta}m$ and coupling constants, which are not well known. The dependence of the scattering lengths on these parameters is found. Finally, we note that a negative $\ensuremath{\Delta}m$, or a change of the order of 2% in the boundary condition or in the ratio of charged to neutral coupling constants, can account for the discrepancy that remains after pion electromagnetic mass splittings are included.
Synthesis of chiral 4,4-disubstituted-dihydropyridazines

Abstract In this paper, a novel general route to the stereospecific synthesis of chiral dihydropyridazines relying on the stereospecific formation of 1,4-diones is presented. The chirality is provided through the application of bicyclic lactams to the synthesis of the required diones. Treatment of the diones with hydrazine produces the pyridazine targets. In this report, the synthesis of four chiral 6-phenyl-4,4-disubstituted-1,4-dihydropyridazines is also presented.
Role of Chelation During Pregnancy in the Lead Poisoned Patient

Cultural and environmental factors can cause lead poisoning in the pregnant patient. The data regarding the reproductive risks associated with chelation during human pregnancy are sparse. Assessment of the exposure setting, including anticipatory counseling for each pregnant woman, would help assure the ideal outcome of no added lead intake.
Multivariate analysis of SEEG signals during seizure

Epilepsy is a neurological disorder that affects tens of millions of people every year and is characterized by sudden-onset seizures which are often associated with physical convulsions. Effective treatment and management of epilepsy would be greatly improved if convulsions could be caught quickly through early seizure detection. However, this is still a largely open problem due to the challenge of finding a robust statistic from the neural measurements. This paper suggests a new multivariate statistic by combining spectral techniques with matrix theory. Specifically, stereoelectroencephalography (SEEG) data was used to generate a series of coherence connectivity matrices which were then examined using singular value decomposition. Tracking the relative angles of the first singular vectors generated from this data provides an effective way of defining the most dominant characteristics of the SEEG during the normal, the pre-ictal, and the ictal states. This paper indicates that the first singular vector has a characteristic direction indicative of the seizure state and illustrates a data analysis method that incorporates all neural data as opposed to a small selection of channels.
SiRNA nanomedicine: The promise of bioreducible materials

RISC: RNA-induced silencing complex.RNA interference (RNAi) presents an exciting opportunity for the treatment of a wide range of diseases refractory to conventional treatment strategies. However, ...
Integrated InP-InGaAsP tunable coupled ring optical bandpass filters with zero insertion loss

Second and third-order monolithically integrated coupled ring bandpass filters are demonstrated in the InP-InGaAsP material system with active semiconductor optical amplifiers (SOAs) and current injection phase modulators (PMs). Such integration achieves a high level of tunability and precise generation of optical filters in the RF domain at telecom wavelengths while simultaneously compensating for device insertion loss. Passband bandwidth tunability of 3.9 GHz to 7.1 GHz and stopband extinction up to 40 dB are shown for third-order filters. Center frequency tunability over a full free spectral range (FSR) is demonstrated, allowing for the placement of a filter anywhere in the telecom C-band. A Z-transform representation of coupled resonator filters is derived and compared with experimental results. A theoretical description of filter tunability is presented.
Protein localization studies in the age of 'Omics'.

As thousands of new genes are identified in genomics efforts, the rush is on to learn something about the functional roles of the proteins encoded by those genes. Clues to protein functions, activation states and protein–protein interactions have been revealed in focused studies of protein localization. With technical breakthroughs such as GFP protein tagging and recombinase cloning systems, large-scale screens of protein localization are now being undertaken.
Use of tris(2,2'-bipyridine)osmium as a photoluminescence-following electron-transfer reagent for postcolumn detection in capillary high-performance liquid chromatography

The photoluminescence-following electron-transfer (PFET) technique, developed in our laboratory, is a sensitive chromatographic detection method for oxidizable analytes. Because the oxidations are homogeneous, the technique avoids the problem of electrode fouling. A liquid-phase oxidant reacts with the electrochemically active analytes after separation, becoming capable of photoluminescence. Laser-induced photoluminescence is measured to quantitate the analytes. Thus, the electrochemical properties of the oxidant determine the detection selectivity, and the spectroscopic properties define the sensitivity. The properties of tris(2,2‘-bipyridine)osmium (1) were investigated for use as the liquid-phase oxidant in the PFET system. The redox potential of the complex is less positive than that of tris(2,2‘-bipyridine)ruthenium (2); thus, on-line generation of 13+ by reaction with PbO2, and selective oxidation of catechols by 13+, was possible. The mild oxidizing power of 13+ led to a lower background signal (co...
The wholesaler's role in the marketing channel: Disintermediation vs. reintermediation

Abstract The demise of wholesalers as a major distributive institution in marketing channels has been predicted for many decades. The advent of internet-based electronic commerce has been predicted to accelerate the demise of wholesalers through a process of disintermediation. But reality has not conformed to these prognostications. What appears to be occurring is a reconfiguring or realignment of wholesalers in distribution channels, sometimes referred to as reintermediation. This article examines several underlying paradigms that may explain why wholesalers as a major distributive institution (will) continue to play an important role in marketing channels.
Genetic counseling for hereditary pancreatitis – the role of molecular genetics testing for the cationic trypsinogen gene, cystic fibrosis and serine protease inhibitor Kazal type 1

The importance of pretest information, using an accredited DNA laboratory and interpreting the genotype on behalf of the patient and their physicians is emphasized. Care with predictive testing and the strong encouragement to involve a specialist genetic counseling service is made. A similar approach to genetic testing should be used when children are involved. Because of the incomplete pickup of PRSS1 mutations, particularly of a limited mutation panel of R122H and N291 (perhaps with A16V), a diagnosis of HP cannot be ruled out by molecular genetic testing alone. The A16V mutation has a reduced penetrance, and its contribution to pancreatitis remains unclear. The advice to patients with genetic forms of pancreatitis is a strong encouragement to avoid smoking, to avoid alcohol, and to remain in contact with clinical and research groups for their follow-up and screening trials for early pancreatic cancer. The remaining issues are of how wide to cast the net of investigation in patients with unexplained pancreatitis, particularly looking for mutations in the CFTR and lower penetrance genes such as PSTI/SPINK1.
Correlates of willingness to consider organ donation among Blacks.

Professionals in the health care and organ procurement fields reveal that black Americans display limited commitment to organ donation. The present study represents an attempt to shed some light on this issue by examining the relationship of selected demographic, knowledge and attitude-belief variables to willingness to consider organ donation within a black population. Findings indicated that only a few of the demographic and knowledge variables were related to willingness to consider organ donation. All of the attitude-belief variables, however, were found to be significantly associated with the dependent variable. Implications of the findings for recruiting black organ donors and future research are discussed.
Elevated mercury measured in snow and frost flowers near Arctic sea ice leads

[1] Elevated mercury concentrations have been reported in arctic coastal snow far from emission sources. The mercury is deposited during mercury depletion events (MDEs), a set of photochemical atmospheric reactions involving reactive halogens. The highest mercury concentrations are clustered near the coast, leading to speculation that sea ice or sea ice leads play a role in MDEs. The nature of this connection is not fully understood. We report mercury concentrations up to 820 ng/L in snow and frost flowers along sea ice leads near Barrow, Alaska. These concentrations are nine times higher than values from nearby coastal snow and are almost half of the mercury maximum contaminant level in United States drinking water. The high values were found only near leads that had convective plumes above open water suggesting that the same processes that produce a supersaturated environment for water vapor near sea ice leads may be instrumental in mercury deposition.
Repeated amphetamine administration induces a prolonged augmentation of phosphorylated cyclase response element-binding protein and Fos-related antigen immunoreactivity in rat striatum

Semi-quantitative immunocytochemistry was used to investigate the levels of cyclase response element-binding protein, phosphorylated cyclase response element-binding protein, Fos and Fos-related antigen immunoreactivity in the striatum of rats after acute or repeated amphetamine administration. Rats were perfused 20 min (phosphorylated cyclase response element-binding protein) or 2 h (cyclase response element-binding protein, phosphorylated cyclase response element-binding protein, Fos, Fos-related antigen) after a single injection (5 mg/kg, i.p.) or five daily injections of amphetamine. The latency to onset of stereotypical behaviors was significantly reduced in rats exposed to repeated amphetamine as compared to acute amphetamine, indicating development of behavioral sensitization. Cyclase response element-binding protein immunoreactivity was not altered in the dorsal or ventral striatum following acute or repeated amphetamine. Phosphorylated cyclase response element-binding protein immunoreactivity was significantly induced 20 min, but not 2 h, following acute amphetamine, whereas a significant induction of phosphorylated cyclase response element-binding protein immunoreactivity was found 20 min and 2 h after repeated amphetamine in the dorsal striatum only. Fos immunoreactivity was significantly induced in the dorsal striatum following acute and repeated amphetamine. Fos immunoreactivity in the core of the nucleus accumbens was significantly increased following repeated amphetamine only. Acute amphetamine induced, and repeated amphetamine further augmented, Fos-related antigen immunoreactivity in the dorsal striatum, while not affecting Fos-related antigen immunoreactivity in the nucleus accumbens. These data demonstrate that repeated amphetamine administration results in a prolonged induction of phosphorylated cyclase response element-binding protein and Fos-related antigen immunoreactivity in the dorsal striatum, indicating that alterations in striatal gene expression associated with the development of behavioral sensitization may be mediated, in part, by these transcription factors.
Mapping regional cerebral vascular transit time by simultaneous determination of local cerebral blood flow and local cerebral blood volume.

We developed a method for autoradiographic mapping of regional cerebral transit time (CTT) by simultaneously measuring local cerebral blood flow (LCBF) and local cerebral blood volume (LCBV). Previously described single-tracer techniques for determination of LCBF and LCBV were modified for dual-tracer,99mTc and14C, autoradiography and used to create digital images of LCBF and LCBV from the same brain sections in a series of normal rats. The images were aligned and ratio images (LCBV/LCBF) were then generated which reflected CTT. Regional cerebral transit time was found to vary significantly throughout the brain in a pattern only partially related to that of blood flow. Such CTT heterogeneity could cause errors in implementation of kinetic models which assume uniform or monovariant distributions of vascular transit time.
“The Colored Man Can’t Fix Nothing with the Law”: Carceral Spaces in August Wilson’s The Piano Lesson

August Wilson’s “Pittsburgh Cycle,” a play written for each decade of the twentieth century, reveals an ongoing engagement with the nature of race, crime, and punishment. Almost none of the male characters in Wilson’s cycle is imprisoned during the course of the play in which he appears, yet most share the experience of imprisonment, and thus carceral places occupy an important rhetorical space in his dramaturgy. Specifically, in The Piano Lesson, Wilson casts prison as metaphor and metonym of modern-day bondage, historicizing social forms of control that have circumscribed the social, civil, and legal rights of the African American community.
Comparison of an instrumental and modified Kjeldahl technique for determination of nitrogen in niobium and tantalum alloys.

Abstract Results obtained for the determination of nitrogen in two tantalum alloys and six niobium alloys by modified Kjeldahl and Leco TC-30 nitrogen—oxygen determinator are compared. In the 5–25 ppm range, for tantalum alloys, the relative standard deviation was 3–9% by the Kjeldahl procedure and 9–11% by the instrumental technique. In the range 30–80 ppm, for niobium alloys, the relative standard deviation was 2–8% by the Kjeldahl procedure and 5–7% by the instrumental technique.
Memory models for open-nested transactions

Open nesting provides a loophole in the strict model of atomic transactions. Moss and Hosking suggested adapting open nesting for transactional memory, and Moss and a group at Stanford have proposed hardware schemes to support open nesting. Since these researchers have described their schemes using only operational definitions, however, the semantics of these systems have not been specified in an implementation-independent way. This paper offers a framework for defining and exploring the memory semantics of open nesting in a transactionl-memory setting.Our framework allows us to define the traditional model of serializability and two new transactional-memory models, race freedom and prefix race freedom. The weakest of these memory models, prefix race freedom, closely resembles the Stanford openesting model. We prove that these three memory models are equivalent for transactional-memory systems that support only closed nesting, as long as aborted transactions are "ignored." We prove that for systems that support open nesting, however, the models of serializability, race freedom, and prefix race freedom are distinct. We show that the Stanford TM system implements a model at least as strong as prefix race freedom and strictly weaker than race freedom. Thus, their model compromises serializability, the property traditionally used to reason about the correctness of transactions.
Effects of cytochalasin B on pancreatic acinar cell structure and secretion

The effects of cytochalasin B (CB) on pancreatic structure and amylase release were studied by use of pancreatic fragments, isolated acini and isolated acinar cells. In pancreatic fragments and isolated acini CB caused the disappearance of microfilaments underlying the apical plasma membrane, loss of apical microvilli and luminal swelling, the last of which was greatly enhanced by addition of protein secretagogues. CB had no effect on basal amylase release but inhibited bethanechol-stimulated amylase in both fragments and acini. Isolated acinar cells, while retaining overall polarity, had lost most of the apical specialization including the microfilament and microvillous complex. Cells were still able to release amylase in response to bethanechol but this release was not affected by CB. The only structural effect of CB on isolated cells was margination of zymogen granules against the plasma membrane. This was, however, not accompanied by increased amylase release. It is concluded that microfilaments are important in maintaining the pancreatic acinar structure. Interference with this structure by CB leads to inhibition of bethanechol-stimulated amylase release. Microfilaments, however, may not play a direct role in secretion.
Measurements of single chain form factors by small-angle neutron scattering from polystyrene blends containing high concentrations of labelled molecules☆

Abstract A series of small angle neutron scattering measurements on blends of normal polystyrene (PSH) and labelled (deuterated) polystyrene (PSD) have been made with concentrations of PSD from 5 to 50 mol %. It is shown that the single chain form factor of the polymer in bulk can be obtained from a single concentration measurement for any concentration of labelled molecules, providing the molecular weights of the parent and labelled molecules are the same and the molecular weight distributions are narrow.
Investigating a few key issues of ionomeric polymer conductive network composite electromechanical transducers

Traditional ionic polymer/conductor network composite (IPCNC) electromechanical actuators exhibit low actuation speed and efficiency. In order to improve these parameters while still maintaining low voltage operation, we investigated IPCNC with a range of composite layer (active layer) and middle ionomer layer (passive layer) thicknesses. We show that it is the slow ion transport in the porous composite electrode layer that limits the actuation speed of IPCNCs. By reducing the thickness of the composite electrode layers, both the actuation speed and efficiency can be improved. Moreover, we show that the IPCNC actuator speed and efficiency are intimately related to the morphology of the composite electrode layer and the conductor network composites fabricated by ionic self-assembled layer-by-layer (LBL) exhibit higher strain response compared with that from the traditional IPCNC. For example, LBL composites show very high intrinsic strain of about 7%. Detailed device analysis points out directions of further improvement of these actuators.
Pumps and Pipes

Introduction “The solution to our problems most likely lie in someone else’s toolbox. The challenge is in finding it.” A significant problem in medical technology development, and perhaps the energy business, is that developers are very in-bred — often exposed only to like-minded individuals, which in turn can prevent innovation and maturation of “out-of-the-box” ideas. We believe that great benefit may be gained by exposing cardiovascular and imaging researchers to technology currently available in the oil and gas world. Thus was created the “Pumps and Pipes” symposium, a collaboration between Houston’s two most prominent industries. Pumps and Pipes is a problem-focused forum analyzing issues relevant to both the energy and medical worlds. The goal is to stimulate discussion, spark ideas and brainstorm with industry counterparts to explore complementary technologies using common language and terminology, with such themes as “Docs and Rocks,” “The Other Guy’s Toolkit,” and “Better Together, and “No Boundaries.”
Experimental Study of Interfacial Shear Stresses in FRP-Strengthened RC Beams

This paper presents the results of an experimental study on the distribution of shear stresses along the interface between concrete and the carbon fiber-reinforced polymer (FRP) in 29 plate-strengthened beams, where the primary test variables are: Clear cover, plate length, plate thickness (area), and compressive strength of concrete. FRP strain measurement was accomplished using either the photographic technique of digital image correlation or a series of electrical-resistance strain gages, both providing similar results. The distribution of shear stresses is found to be smoother than predicted by several analytical expressions available in the literature. Another substantial observation is the existence of a second region of peak stress, occurring near the center of the shear span in all of the beams with longer plate lengths, which the authors believe is associated with the singular application of shear corresponding to the point load, as well as the transition from elastic to plastic behavior occurrin...
Microstructural evolution and corrosion resistance of fusion welds on alloy CN3MN made with IN686 filler metal

AbstractCast superaustenitic stainless steels with ∼6 wt-%Mo are used in applications requiring good corrosion resistance. However, the weld corrosion resistance is reduced due to Mo microsegregation. Ni based filler metals with higher Mo concentrations are typically used to compensate for this problem. The weld corrosion resistance and microstructural evolution are controlled by the weld composition, which is a function of the welding parameters. This article describes the effect of weld composition on the microstructure and corrosion behaviour of welds on cast alloy CN3MN using IN686 filler metal. The amount of interdendritic σ phase was independent of dilution due to offsetting changes to the nominal composition, eutectic composition and distribution coefficient. The weld corrosion resistance improved significantly with decreasing dilution due to higher concentrations of Mo in the fusion zone. A post-weld heat treatment of 1150°C for 1 h restored the corrosion resistance, which is attributed to weld ho...
Anisotropic NMR interaction tensors in the decamethylaluminocenium cation.

Solid-state NMR experiments, analytical and numerical simulations of solid NMR powder patterns, ab initio self-consistent field and hybrid density functional theory calculations, and single-crystal X-ray diffraction are used to characterize the molecular structure and anisotropic NMR interaction tensors in the bis(pentamethylcyclopentadienyl)aluminum cation, [Cp*2Al]+. This highly symmetric main group metallocene has a structure analogous to that of ferrocene and the cobaltocenium cation. The single-crystal X-ray diffraction structure is reported for [Cp*2Al][AlCl4]. Solid-state 27Al{1H} magic-angle spinning and static NMR experiments are used to study the aluminum chemical shielding and electric field gradient tensors, revealing axial symmetry in both cases with a large chemical shielding span of Ω = 83(3) ppm and a small nuclear quadrupole coupling constant, CQ(27Al) = 0.86(10) MHz. Carbon-13 CPMAS NMR experiments in combination with ab initio calculations and simulations of the effects of chemical exch...
Osteoarthritis: Joint instability and OA: do animal models provide insights?

Joint injury represents a major risk factor for the development of osteoarthritis, but a link between severity of injury and the level of cartilage damage is difficult to test in humans. However, promising advances in our understanding of this relationship have been made with the aid of animal models of joint injury.
Rapid Down-Regulation of c-jun Protooncogene Transcription by Progesterone in the Avian Oviduct*

Previous work in this and other laboratories has shown that steroids rapidly regulate the expression of nuclear protooncogenes. In this present study, we have investigated the effect of progesterone (Pg) on the expression of c-jun in the avian oviduct system and its promoter activity in avian liver cells. Pg treatment of estrogen-withdrawn chickens brings about a decrease in the steady state mRNA level of the protooncogene c-jun within 30 min. This decrease is steroid dose dependent and gene specific. Using nuclear run-off transcription analyses, this rapid regulation was shown to occur at the level of gene transcription, as the rate of c-jun transcription decreases by more than 80% within 15 min after progesterone treatment. As expected, ovalbumin gene transcription is increased only after a lag period of 4 h following Pg treatment. In other studies, we have linked the c-jun promoter sequences between -1000 and +192 to chloramphenicol acetyltransferase reporter gene and cotransfected them into transforme...
Mammalian cyclin/PCNA (DNA polymerase δ auxiliary protein) stimulates processive DNA synthesis by yeast DNA polymerase III

Abstract Human cyclin/PCNA (proliferating cell nuclear antigen) is structurally, functionally, and immunologically homologous to the calf thymus auxiliary protein for DNA polymerase delta. This auxiliary protein has been investigated as a stimulatory factor for the nuclear DNA polymerases from S. cerevisiae. Calf cyclin/PCNA enhances by more than ten-fold the ability of DNA polymerase III to replicate templates with high template/primer ratios, e.g. poly(dA).oligo(dT) (40:1). The degree of stimulation increases with the template/primer ratio. At a high template/primer ratio, i.e. low primer density, cyclin/PCNA greatly increases processive DNA synthesis by DNA polymerase III. At low template/primer ratios (e.g. poly(dA).oligo(dT) (2.5:1), where addition of cyclin/PCNA only minimally increases the processivity of DNA polymerase III, a several-fold stimulation of total DNA synthesis is still observed. This indicates that cyclin/PCNA may also increase productive binding of DNA polymerase III to the template-primer and stabilize the template-primer-polymerase complex. The activity of yeast DNA polymerases I and II is not affected by addition of cyclin/PCNA. These results strengthen the hypothesis that yeast DNA polymerase III is functionally analogous to the mammalian DNA polymerase delta.
Antagonist: Should we eradicate Helicobacter pylori before long term antireflux therapy?

Patient management recommendations that might become health care policy should be based on the highest level of evidence. The evidence supporting the recommendation to “test and treat” for Helicobacter pylori infection before starting long term antireflux treatment falls well short of this standard. This recommendation arose directly from the report by Kuipers and colleagues1 in 1996 that the prevalence of corpus glandular atrophy increased during chronic omeprazole treatment in patients infected with H pylori . We were pleased to have another reason to eradicate H pylori ; the prevailing wisdom was that no H pylori should go unpunished. This aggressive approach has been challenged, particularly in the case of patients with gastro-oesophageal reflux disease (GORD). Approximately 42% of adults in the USA suffer from GORD.2 Nearly 7% experience heartburn on a daily basis,3 making them potential candidates for proton pump inhibitor (PPI) therapy and, therefore, testing for H pylori infection. Apart from the obvious economic and antimicrobial resistance implications, growing evidence indicates that H pylori infection protects against the complications of …
Influence of delta 9-tetrahydrocannabinol on expression of histone and ribosomal genes in normal and transformed human cells

Abstract The influence of Δ 9 -tetrahydrocannabinol ( Δ 9 -THC) on the cellular levels of histone mRNAs and ribosomal RNAs was examined in several normal and transformed human cell lines—HeLa S3 cells, WI-38 human diploid fibroblasts, SV40-transformed WI-38 cells, and A549 lung carcinoma cells. RNA sequences were quantitatively assayed by electrophoretic fractionation, transfer to nitrocellulose, and hybridization with cloned genomic human histone or ribosomal DNA sequences. Treatment with Δ 9 -THC (10–40 μM) for 10 hr resulted in a concentration-dependent decrease in the representation of H2A, H2B, H3 and H4 histone mRNAs without a significant inhibitory effect on the levels of ribosomal RNAs. The cannabinoid-mediated inhibitory effect on histone gene expression was less evident in cells with active drug-metabolizing systems.
Combined Sensing and Actuation: A New Control Laboratory Experiment

This paper describes a new control experiment developed for Mechanical Engineering undergraduate students. The experiment with a Shape Memory Alloy (SMA) actuated robotic arm is designed for the senior undergraduate laboratory (ME4006) in the Department of Mechanical Engineering at Virginia Tech. ME4006 is designed to provide the students with experience in experimental investigation of mechanical engineering systems. In designing this control experiment it was intended for the students to have a hands-on experiment with smart materials. Furthermore, students learn about control problems and limitations of theses materials along with sensing and actuation advantages of the SMAs. The experiment uses a problem solving approach; students are not given a procedure to follow for conducting the experiment. The problem is described in a memorandum to the students from a supervisor, who defines the purpose of the problem and defines the audience for the report.© 2004 ASME
Effects of gestational exposure to methylmercury and dietary selenium on reinforcement efficacy in adulthood.

It has recently been demonstrated that developmental exposure to methylmercury (MeHg) is associated with perseveration on operant tasks. An understanding of the behavioral mechanisms underlying this phenomenon may improve human testing of MeHg exposures and could provide insight into clinical syndromes that include perseveration as a component. One possible mechanism is that MeHg-induced enhancement of reinforcer efficacy produces a “reinforcement trap” that inhibits change in novel situations. Rats were exposed gestationally to 0, 0.5 or 5 ppm mercury (Hg) as MeHg via maternal drinking water. They also received a diet during gestation and throughout life that was marginal (0.06 ppm) or rich (0.6 ppm) in selenium (Se), a nutrient believed to protect against MeHg's toxicity. Reinforcer efficacy was evaluated using a progressive ratio schedule of reinforcement during adulthood. Maximum ratio obtained (MRO) was determined using 20 or 60 mg sucrose pellets and with ratio requirements that increased at 5% or 20% per reinforcer. MRO was related to the rate at which the ratio increased, reinforcer magnitude, sex, and exposure regimen; MRO was increased for the 0.6 ppm Se, 5 ppm Hg group. This extends an earlier observation that developmental MeHg exposure enhances reinforcer efficacy, an effect that could be related to reports of perseveration.
Caspase and calpain substrates: Roles in synaptic plasticity and cell death

Neurons are an unusual type of cell in that they send processes (axons and dendrites) over great distances. This elaborate morphology, together with their excitability, places neurons at risk for multiple insults. Recent studies have demonstrated that apoptotic and excitotoxic mechanisms not only contribute to neuronal death, but also to synaptic dysfunction and a breakdown in neural circuitry (see Mattson and Duan [1999] J. Neurosci. Res. 58:152-166, this issue). Proteases of the caspase and calpain families have been implicated in neurodegenerative processes, as their activation can be triggered by calcium influx and oxidative stress. Caspases and calpains are cysteine proteases that require proteolytic cleavage for activation. The substrates cleaved by caspases include cytoskeletal and associated proteins, kinases, members of the Bcl-2 family of apoptosis-related proteins, presenilins and amyloid precursor protein, and DNA-modulating enzymes. Calpain substrates include cytoskeletal and associated proteins, kinases and phosphatases, membrane receptors and transporters, and steroid receptors. Many of the substrates of caspases and calpains are localized in pre- and/or postsynaptic compartments of neurons. Emerging data suggest that, in addition to their roles in neurodegenerative processes, caspases and calpains play important roles in modulating synaptic plasticity. The present article provides a review of the properties of the different caspases and calpains, their roles in cell death pathways, and the substrates upon which they act. Emerging data are considered that suggest key roles for these proteases in the regulation of synaptic plasticity.
Wireless energy delivery and data communication for biomedical sensors and implantable devices

In this paper, we present a wireless power transfer and communication method for biomedical sensors and implants by taking advantage of recently developed witricity technology. New witricity resonator and system designs are described and evaluated by performing both in vitro and in vivo experiments. When compared to the current designs, these new witricity designs demonstrate much improved performances for wireless energy delivery to and data communication with biomedical sensors and implantable devices from outside the human body, providing a higher efficiency and a longer transmission distance.
New insights into the dynamics between reef corals and their associated dinoflagellate endosymbionts from population genetic studies

The mutualistic symbioses between reef-building corals and micro-algae form the basis of coral reef ecosystems, yet recent environmental changes threaten their survival. Diversity in host-symbiont pairings on the sub-species level could be an unrecognized source of functional variation in response to stress. The Caribbean elkhorn coral, Acropora palmata, associates predominantly with one symbiont species (Symbiodinium ‘fitti’), facilitating investigations of individual-level (genotype) interactions. Individual genotypes of both host and symbiont were resolved across the entire species’ range. Most colonies of a particular animal genotype were dominated by one symbiont genotype (or strain) that may persist in the host for decades or more. While Symbiodinium are primarily clonal, the occurrence of recombinant genotypes indicates sexual recombination is the source of this genetic variation, and some evidence suggests this happens within the host. When these data are examined at spatial scales spanning the entire distribution of A. palmata, gene flow among animal populations was an order of magnitude greater than among populations of the symbiont. This suggests that independent micro-evolutionary processes created dissimilar population genetic structures between host and symbiont. The lower effective dispersal exhibited by the dinoflagellate raises questions regarding the extent to which populations of host and symbiont can co-evolve during times of rapid and substantial climate change. However, these findings also support a growing body of evidence, suggesting that genotype-by-genotype interactions may provide significant physiological variation, influencing the adaptive potential of symbiotic reef corals to severe selection.
An advanced spike detection and sorting system

This paper proposes a comprehensive new neural spike detection and sorting system. As a critical first step to all neuroscientific studies of the nervous system using chronically implanted electrodes in the brain areas of interest, high performance neural spike detection and sorting from the massive amount of continuously recorded neural data is a challenging task, especially in real time applications such as brain machine interface. Many existing spike detection and sorting systems use simple thresholding as the first step to admit a large number of possible spikes for further sorting using various clustering algorithms. Significant efforts have gone into developing sophisticated sorting algorithms, many of which are time consuming in applications. In this paper, we develop a new system that is based on a reliable detection algorithm using multiple correlations of wavelet coefficients, which is robust and can be implemented in real time. Because of the advanced detection step, the system becomes less demanding on the performance of the sorting or clustering algorithms. This has simplified the overall system, and made real time interface and other real time applications possible. We tested the newly proposed system extensively, compared with several popular systems including commercial packages. While most thresholding based detection systems usually create a large number of false alarms, test results show that our proposed system on both artificial and real neural data have produced few false alarms but with high detection rates.
Construction of Dependent Dirichlet Processes based on Poisson Processes

We present a novel method for constructing dependent Dirichlet processes. The approach exploits the intrinsic relationship between Dirichlet and Poisson processes in order to create a Markov chain of Dirichlet processes suitable for use as a prior over evolving mixture models. The method allows for the creation, removal, and location variation of component models over time while maintaining the property that the random measures are marginally DP distributed. Additionally, we derive a Gibbs sampling algorithm for model inference and test it on both synthetic and real data. Empirical results demonstrate that the approach is effective in estimating dynamically varying mixture models.
Performance of an automated immature granulocyte count as a predictor of neonatal sepsis.

Neonatologists use immature granulocytes (IG) in manual differential counts as an indicator of sepsis. This study was designed to compare the predictive ability of automated vs manual IG counts for neonatal sepsis. Infants undergoing sepsis evaluation were identified prospectively for study if a CBC count was obtained in temporal proximity to the blood culture. Automated IG counts were obtained from the research software of the Sysmex XE-2100 (Sysmex, Kobe, Japan). Manual average IG counts were obtained from two 100-cell manual differential counts independently performed by a technologist and a hematopathology resident. A comparative analysis of manual and automated IG counts showed considerable overlap of ranges. The highest positive blood culture rate occurred in the nonneutropenic preterm subset of infants older than 7 days (21/55 [38%]). For these infants, elevated IG counts by manual and automated methods were associated significantly with positive blood culture results (odds ratio, manual, 3.74; odds ratio, automated, 3.63), albeit with low sensitivity.
Hippocampal size positively correlates with verbal IQ in male children

Historically, there have been numerous proposals that the size of the brain correlates with its capacity to process information. Little is known, however, about which specific brain regions contribute to this correlation in children and adolescents. This study evaluated the relationship between intelligence and the size of various brain structures in typically developing male children 8-18 yrs of age. Magnetic resonance imaging (MRI) scans were used to measure the volume of the cerebrum, cerebral gray and white matter, cerebellum, amygdala, and hippocampus. Gray matter and hippocampal volume significantly correlated with full scale and verbal IQ. Since the hippocampus strongly correlated with verbal but not performance IQ, our findings reinforce the hypothesis that the hippocampus is involved in declarative and semantic learning, which contributes more notably to verbal IQ, than to performance IQ. Given the substantial evidence for environmentally induced changes in hippocampal structure, an unresolved issue is whether this relationship reflects genetically determined individual variation or learning induced plasticity.
An Early Use of Bid Rent Functions

This paper examines Launhardt's contributions to the bid rent function and the patterns of land use. It shows that principles of bid rent analysis pioneered by Launhardt in 1885 have found applicat...
Prolonged Colonization with Vancomycin-Resistant Enterococcus faecium in Long-Term Care Patients and the Significance of “Clearance”

Little is known about the persistence of colonization with vancomycin-resistant Enterococcus faecium (VRE) in the nononcologic, non-intensive care unit patient. We studied all patients who had VRE isolated on > or =2 occasions of > 1 year apart (Study A) and those who had been "cleared" of VRE colonization after 3 negative stool cultures (Study B). Twelve patients had stored VRE isolates recovered > 1 year apart (Study A), and 58% of paired isolates were genotypically related according to pulsed field gel electrophoresis patterns. In Study B, stool samples were obtained weekly from 21 "cleared" patients for 5 weeks, which revealed that 24% were VRE positive. For these culture-positive patients, 72% of the cultures failed to detect VRE. Recent antibiotic use was significantly more common in the culture-positive patients, as compared with culture-negative patients (P=.003). Colonization with VRE may persist for years, even if the results of intercurrent surveillance stool and index site cultures are negative. Cultures for detection of VRE in stool samples obtained from patients declared "cleared" are insensitive.
Values: Reviving a Dormant Concept

Over the past decades, the concept of values has gone in and out of fashion within sociology. Relatively recent advances in both the conceptualization and measurement of values offer the potential for a reincorporation of values into sociological work. Sociologists often employ cursory understandings of values, imbuing values with too much determinism or viewing them as too individually subjective. The concept is employed sporadically in sociological subdisciplines. This review maps out the contours of the various approaches to linking values with culture, social structure, and individual behavior. We discuss theoretical and empirical approaches to values, organizing the broad literature to address three questions: (a) What are values? (b) Where do values come from? and (c) What do values do? We identify important research findings and suggest areas for future inquiry.
Near‐simultaneous measurement of low‐energy electrons by sounding rocket and satellite

An auroral sounding rocket was launched from Fort Churchill at 0453 UT on April 24, 1968. At the time of the rocket flight, the Vela 3B satellite was passing through the magnetotail plasma sheet at very nearly the same magnetic local time. Electron spectra obtained from experiments on these vehicles are well described by central Maxwell-Boltzmann populations, with indications of a high-energy tail; the satellite spectra also suggest the presence of a low-energy tail. The higher-temperature spectra measured on the rocket may be derived from the satellite spectra by adiabatic compression.
Development of corticogeniculate synapses in the cat.

The development of corticogeniculate synapses was studied in 16 cats ranging in age from newborn to adult. Tritiated proline was injected into areas 17 and 18 of the visual cortex in order to label corticogeniculate terminals in lamina A of the dorsal lateral geniculate nucleus. The labeled terminals were then characterized ultrastructurally using electron microscopic autoradiography. Labeled synaptic profiles were found in newborn kittens, indicating that corticogeniculate connections are present in the cat at birth. Morphologically, however, many corticogeniculate endings in newborn and 1-week-old kittens are different from those in older animals in that they do not form well-defined terminal boutons, and their synaptic vesicles are often loosely packed. In kittens 2 weeks of age and older, corticogeniculate axons end as RSD terminals exclusively; i.e., they are relatively small in size and contain round, densely packed synaptic vesicles, and occasionally an electron-dense mitochondrion (Guillery: Z. Zellforsch. 99: 1-38, '69). However, not all RSD terminals in the LGN represent input from visual cortex. Injections of 3H-proline into the mesencephalic reticular formation also label RSD terminals selectively in the lateral geniculate nucleus. At all ages corticogeniculate axons make synaptic contacts with dendrites exclusively, and they are always presynaptic. This suggests that the essential pattern of corticogeniculate synapses is formed early and is not altered during subsequent development. Quantitatively, there is no significant change in the size of corticogeniculate terminals or their synaptic vesicles in kittens 2 weeks of age (the youngest measured) and older. In contrast, the synaptic contact lengths of these terminals decreases about 28% between 2 and 12 weeks. During this same period there is approximately a twofold increase in the density of corticogeniculate terminals in the neuropil of lamina A. Since the volume of neuropil in lamina A increases almost fourfold between 2 and 12 weeks, the doubling of corticogeniculate terminal density represents about an eightfold increase in terminal number. After 12 weeks there is little change in the length, density, or number of corticogeniculate synaptic contacts, which suggests that the morphological development of the corticogeniculate pathway is essentially complete by this age.
A Cost-Effectiveness Analysis of Diagnostic Strategies for Symptomatic Patients with Ileal Pouch-Anal Anastomosis

A cost-effectiveness analysis of diagnostic strategies for symptomatic patients with ileal pouch–anal anastomosis
Phoneme-monitoring in the context of different phonetic sequences

Abstract The order of some conjoined words is rigidly fixed (e.g. dribs and drabs/*drabs and dribs). Both phonetic and semantic factors can play a role in determining the fixed order. An experiment was conducted to test whether listeners’ reaction times for monitoring a predetermined phoneme are influenced by phonetic constraints on ordering. Two such constraints were investigated : monosyllable-bisyllable and high-low vowel sequences. In English, conjoined words occur in such sequences with much greater frequency than their converses, other factors being equal. Reaction times were significantly shorter for phoneme monitoring in monosyllable-bisyllable sequences than in bisyllable-monosyllable sequences. However, reaction times were not significantly different for high-low vs. low-high vowel sequences.
What can mice tell us about how vision works

Understanding the neural basis of visual perception is a long-standing fundamental goal of neuroscience. Historically, most vision studies were carried out on humans, macaques and cats. Over the past 5 years, however, a growing number of researchers have begun using mice to parse the mechanisms underlying visual processing; the rationale is that, despite having relatively poor acuity, mice are unmatched in terms of the variety and sophistication of tools available to label, monitor and manipulate specific cell types and circuits. In this review, we discuss recent advances in understanding the mouse visual system at the anatomical, receptive field and perceptual level, focusing on the opportunities and constraints those features provide toward the goal of understanding how vision works.