cssi/SciSciGPT-SciSciNet huggingface dataset:
T Cell Receptor V Genes in Multiple Sclerosis: Increased Use of TCRAV8 and TCRBV5 in MBP-Specific Clones

It is probable that myelin-reactive T cells, including those specific for myelin basic protein (MBP) contribute to the pathogenesis of multiple sclerosis (MS). Although many studies have characterized the specificity, MHC restriction, and V gene use of MBP-specific T cells, there is little agreement as to whether there are differences between MS and controls, and how HLA-DR2, a risk factor for MS, might influence selection of MBP-specific T cells. We here discuss models in which MHC class II alleles could help shape the TCR repertoire, and then review more than 750 clones reported in the literature. The major finding from our analysis is that both TCRAV8 and BV5, but not BV6 were utilized more frequently in MS patients than non-MS patients in response to MBP, although no differences were found between DR2+ versus DR2- donors. These data indicate HLA-independent differences in the T cell repertoire between MS patients and controls that may be important for targeted TCR-based therapy. Moreover, we conclude that (1) HLA-DR alleles preferentially restrict MBP responses, although MS patients tend to use HLA-DQ and -DP alleles more often than control donors; (2) HLA-DR2 alleles are used to restrict only about half the MBP responses in MS patients, significantly less than in control patients; (3) the DRB1*1501 and DRB5*0101 subtypes within the Dw2 haplotype are used relatively equally to restrict MBP responses. In this context, we review the results of our previous clinical trials in progressive MS patients, demonstrating the ability of TCRBV5S2 peptides to induce clinically relevant regulatory responses that inhibit MBP-specific Th1 cells through a bystander suppression mechanism.
Employee turnover in the hospitality industry: an analysis based on the CANE model of motivation.

ABSTRACT Employee turnover is reaching crisis proportions for many organizations who struggle to maintain proper staffing levels in a tight labor market (Wilson, 2000). Turnover has been a measure of performance in organizations that is expensive in terms of financial and operational effectiveness. The current study used the Commitment And Necessary Effort (CANE) model of motivation (Clark, 1998, 1999) to determine if levels of motivated thinking and behavior, indexed as choice, persistence, and effort, and influenced by self-efficacy, support, emotion, and task value, impacted employee turnover rates in the hotel and quick service restaurant segments of the hospitality industry. Using regression analysis, it was determined that the motivation component of the CANE model was a statistically significant variable when analyzing turnover in the current study. Over 96% of the variation in turnover of the 22 worksites analyzed was explained by the components of the motivation model. This research is important ...
Anticancer Therapy SMRT-ens Up: Targeting the BCL6-SMRT Interaction in B Cell Lymphoma

Transcription factors have proven to be difficult targets for the development of small-molecule drugs. In this issue of Cancer Cell , Cerchietti et al. identify and characterize a specific, small-molecule inhibitor of BCL6, an oncogenic transcriptional repressor, that has high clinical promise for treating diffuse large B cell lymphoma.
Microbial and enzymatic inactivation of prions in soil environments

Abstract Transmissible spongiform encephalopathies (TSEs) are fatal, infectious neurodegenerative diseases that affect humans and other mammals. The etiological agent in TSEs is the prion and is thought to be composed of aggregated, β-sheet-rich conformers of the prion protein (PrPTSE) derived from misfolding of a benign cellular form of the same protein. Prions are remarkably resistant to inactivation and can persist and remain infectious in the environment for years. Environmental routes of TSE transmission are implicated in chronic wasting disease (CWD) of deer, elk and moose and in scrapie of sheep and goats. Soil is thought to be an important reservoir of CWD and scrapie infectivity. The extent to which prions are inactivated by natural processes in soils is unclear, and methods for inactivating TSE agents in soil are currently lacking. This critical review discusses current knowledge on the degradation of PrPTSE and inactivation of prions by individual bacterial species, mixed microbial consortia, and isolated bacterial and archaeal enzymes, and highlights areas warranting further research. Research conducted to date indicates that few microorganisms are able to degrade PrPTSE. Fungi have not been evaluated for their ability to inactivate TSE agents. Of proteases reported to degrade PrPTSE, most are serine proteases and many require harsh conditions (e.g., elevated temperature, high pH, detergent) for optimal PrPTSE-degrading activity. Declines in the levels of PrPTSE are not always accompanied by equivalent decreases in TSE infectivity. Most biodegradation studies reported to date did not examine effects on TSE infectivity and must therefore be considered inconclusive with respect to the likely impact on prion disease transmission. Improved understanding of the factors affecting prion inactivation is required to discern natural routes of prion inactivation or implement effective practices outside of the laboratory.
Predicting School Performance with the Early Screening Inventory.

Criteria are proposed for defining and selecting preschool developmental screening instruments. These criteria include the purpose, breadth, and psychometric properties of screening tests. The Early Screening Inventory (ESI) is a developmental screening instrument designed to satisfy these criteria. The test samples developmental, rather than school achievement, abilities and focuses on performance in a wide range of developmental areas. The results of several reliability and validity studies performed on the ESI are presented, demonstrating that the ESI predicts school performance with moderate to excellent accuracy through the end of second grade. The usefulness and limitations of the ESI in predicting school performance from kindergarten to grade four are discussed.
Measuring Self-Regulation: A Focus on Activity

Ainley and Patrick describe an assessment process designed to “identify self- regulation in action.” In the spirit of this goal, the author offers three suggestions for providing a more holistic and contextual view of self-regulation. These suggestions include (a) expanding the definition of self-regulation used in their studies; (b) measuring self-regulation as a dynamic process rather than as a linear one; and (c) including measures of the context, such as task, interpersonal contacts, and community norms.
Methylolation of α; ω-dinitroalkanes

Abstract The sodium hydroxide catalyzed methylolation of 1,4-dinitrobutane (I) has been found to yield 2,5-dinitro-1,6-hexanediol, (IV; both epimers), and 2,5-bis-hydroxymethyl-2,5-dinitro-1,6-hexanediol (II). No evidence was obtained for the formation of the unsym-metrical diol, 1,1-bis-hydroxymethyl-1,4-dinitrobutane (VI) or the triol (VII). Methylolation of I bis-nitronate ion led to IV and 2,5-dinitro-1-pentanol (V). Similarly, 2,6-dinitro-1-hexanol (X) and 2,6-dinitro-1,7-heptanediol (XI, both epimers) have been prepared from 1,5-dinitropentane.
A Comparison of Regenerated Cell Walls in Tobacco and Cereal Protoplasts

Four independent kinds of observations indicate that the cell wall regenerated by oat (Avena sativa L.) and corn (Zea mays L.) protoplasts in culture is less well developed than that regenerated by tobacco (Nicotiana tabacum L.) protoplasts. Following wall regeneration the cereal protoplasts remained susceptible to osmotic shock upon transfer to water, showed great enlargement, stained poorly with calcofluor white, and maintained a positive internal electrical potential. The development of a negative membrane potential by tobacco protoplasts in culture often occurred simultaneously with the onset of cell division. Since division was observed only in protoplasts which had regenerated good cell walls and had re-established negative membrane potentials it is suggested that culture conditions which favor these two processes should improve protoplast viability.
Rejuvenated volcanism along the southwest rift zone, East Maui, Hawai‘i

East Maui Volcano is the younger and larger of two volcanoes that form the island of Maui, Hawai‘i. Rejuvenated stage (Hāna volcanics) lava flows along the southwest rift zone form a veneer lying disconformably on top of the postshield Kula Volcanics (0.93–~0.36 Ma). Most of the 59 documented Hāna eruptions produced ‘a‘ā flows from large cinder cones. Fourteen new 14C ages and stratigraphic relationships suggest that the onset of rejuvenated volcanism on the southwest rift zone began at least 50 ka, showing that the quiescent period between the postshield and rejuvenated stage on East Maui was ~300,000 years long, the shortest yet documented on any Hawaiian volcano. Eruption frequency on the southwest rift zone steadily increased during the past ~4800 years; there have been at least six eruptions within the past ~960 years. Hāna volcanic activity on the southwest rift zone during the past ~4800 years may have occurred in three episodes, each lasting as long as 1000 years separated by quiescent periods ~500–800 years long. Geochemical data, ages, and geologic relations provide evidence for five multi-flow sequences that were erupted during single events, helping to define the eruptive character or style of rejuvenation stage volcanic activity on the southwest rift zone. Areas covered by the products of individual eruptions vary from 0.14 to ~40 km2, and volumes from 0.0003 to 0.40 km3. Geochemical evidence shows that the Hāna lavas are derived from a small range of parental melts that undergo varying degrees of fractional crystallization. MELTS crystallization simulations suggest that Hāna magmatic evolution occurs at a pressure of ~3 kbar (~10–11 km depth), just above the interface between the volcanic edifice and the oceanic plate. The Hāna volcanics are unique among Hawaiian rejuvenation suites in having been erupted along rift zones with a relatively high eruption frequency from a quasi-steady-state, deep crustal magma reservoir.
A developmental-adaptive model for use in service-matrix planning for youth

As community services for disturbed and retarded children and their families proliferate, more focused attention should turn to early coordinated planning for the variance of normalcy and the prevention of later, more severe childhood and adolescent disorders. This paper describes a model of human development with specific emphasis on the first two decades of the life cycle. Its usefulness as an organizing instrument in community services planning, both for coordinating already present services, as well as for clarifying service areas requiring development, is the major theme. This paper should be of interest to professionals in community mental health and retardation services, as well as to community organization and administrative specialists. It could be catalytic as a vehicle for initiating discussion with local governmental systems involved in child and family health and preventive services planning.
Production visualization for the ASCI one TeraFLOPS machine

The delivery of the first one tera-operations/sec computer has significantly impacted production data visualization, affecting data transfer, post processing, and rendering. Terascale computing has motivated a need to consider the entire data visualization system; improving a single algorithm is not sufficient. This paper presents a systems approach to decrease by a factor of four the time required to prepare large data sets for visualization. For daily production use, all stages in the processing pipeline from physics simulation code to pixels on a screen, must be balanced to yield good overall performance. Performance of the initial visualization system is compared with recent improvements. "Lessons learned" from the coordinated deployment of improved algorithms also are discussed, including the need for 64 bit addressing and a fully parallel data visualization pipeline.
Abstract 1016: Combination low dose 5-azacytidine (AZA) and romidepsin (FK228) therapy re-sensitizes ovarian cancer cells to cisplatin.

Ovarian cancer is the deadliest gynecologic malignancy. Current options for treating platinum-resistant disease are limited by drug choices and toxicities. Epigenetic therapy is emerging as a strategy for reversing tumor resistance and a recent encouraging clinical trial in platinum-resistant ovarian cancer suggests a potential unique application in ovarian cancer. The epigenetic drugs histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) cause chromatin relaxation and multiple anti-tumor effects on cell growth, cell cycle, cell death and deregulation of DNA damage response and repair (DDR) pathways. Among HDACi we have tested in a panel of ovarian cancer cells, the depsipeptide FK228 exerts the most potent growth inhibitory effects in the majority of cells. Therefore, we aimed to determine whether the combination of FK228 and the DNMTi 5-azacytadine (AZA) can re-sensitize ovarian cancer cells to cisplatin more effectively than either agent alone. We found that FK228 synergized with low doses of the DNMTi 5-azacytadine (AZA) in SRB cell growth assays in vitro, and that low dose combinations of the drugs enhanced the growth inhibitory effects of cisplatin. Similar effects were observed when ovarian cancer cells were grown as xenografts in immunocompromised mice in vivo. Furthermore, a key DDR sensor, phosphorylated gamma-H2AX (pH2AX) activation was associated with the enhanced cytotoxic effects of the combination of the epigenetics and may be a marker of response. In conclusion, we have identified a novel combination of epigenetic drugs that can re-sensitize ovarian cancer cells to cisplatin treatment, at least in part through stimulation of pH2AX. Targeting DDR pathways in DDR-deficient ovarian cancer cells with low dose epigenetic drugs represents a promising strategy in ovarian cancer treatment. Citation Format: Andrew Wilson, Lanzi Sinaise, Jade M. Readus, Michelle Park, Anum S. Lalani, Jeanette Saskowski, Dineo Khabele. Combination low dose 5-azacytidine (AZA) and romidepsin (FK228) therapy re-sensitizes ovarian cancer cells to cisplatin. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1016. doi:10.1158/1538-7445.AM2013-1016
Cystic mesothelioma of the peritoneum

A 48-year-old man presented with a 3-month history of weight loss and progressive right lower quadrant abdominal pain. His medical history was notable for appendectomy at age 17. Ultrasonography and computed tomography of the abdomen revealed a 12 cm multicystic mass in the right paracolic space. At laparotomy a large serous cyst was found arising from the lateral wall of the cecum, and four additional small cysts were found on the small bowel mesentery, greater omentum, liver capsule, and right hemi-diaphragm. Complete removal of the tumor was accomplished by right colectomy with extraperitoneal dissection of the large cyst and simple excision of the four smaller cysts. Final pathology with immunohistochemical staining confirmed cystic mesothelioma of the peritoneum. In this report we discuss the diagnostic workup and treatment of this rare disease.
Anthropogenic land-use signals propagate through stream food webs in a California, USA, watershed

Abstract Human development of watersheds can change aquatic ecosystems via multiple pathways. For instance, human rural development may add nutrients to ecosystems. We used naturally occurring stable isotopes in stream food webs to investigate how land use affects stream ecosystems across a gradient of land development in the San Lorenzo watershed, California. Road density was used as a proxy for land development. We found that streams in watersheds with higher road densities had elevated concentrations of phosphate and nitrate. Furthermore, algal δ15N values increased as a function of nitrate concentration, but saturated at approximately 6‰. This saturating pattern was consistent with a two-source mixing model with anthropogenic and watershed sources, fit using Bayesian model fitting. In sites that had >2.6 km roads km−2, anthropogenic sources of N were estimated to represent >90% of the N pool. This anthropogenic N signal was propagated to stream consumers: rainbow trout (Oncorhynchus mykiss), signal crayfish (Pacifasticus leniusculus), and benthic invertebrate δ15N were positively correlated with algal δ15N. Even relatively low density rural human land use may have substantial impacts on nutrient cycling of stream ecosystems.
The Myelodysplastic Syndromes: Diagnosis and Treatment

The myelodysplastic syndromes (MDSs) are common, acquired, clinically challenging hematologic conditions that are characterized by bone marrow failure and a risk of progression to acute leukemia. These disorders can arise de novo, especially in elderly patients or, less often, as a consequence of prior chemotherapy or radiotherapy for an unrelated disease. The MDS classification systems were revised recently and updated. These refined classification and prognostic schemes help stratify patients by their risk of leukemia progression and death; this knowledge can help clinicians select appropriate therapy. Although many treatments for MDS have been proposed and evaluated, at present, only hematopoietic stem cell transplantation offers any real hope for cure, and no available therapy beyond general supportive care offers benefit to more than a minority of patients. However, recent clinical trials enrolling patients with MDS have reported encouraging results with use of newer drugs, including lenalidomide, decitabine, and darbepoetin alfa. Other exciting treatment regimens are being tested. Here, we present a contemporary, practical clinical approach to the diagnosis and risk-stratified treatment of MDS. We review when to suspect MDS, detail how to evaluate patients who may have a form of the condition, explain key features of treatments that are currently available in the United States, and summarize a general, common-sense therapeutic approach to patients with MDS.
Ovarian activity in obese and nonobese women treated with three transdermal contraceptive patches delivering three different doses of ethinyl estradiol and levonorgestrel

Abstract Background The effect of obesity on ovarian follicular suppression in women using low-estrogen dose contraceptive patches has not been determined. Study Design A Phase II, parallel-group, multicenter, three-cycle study evaluated three patches containing different ethinyl estradiol (EE) and levonorgestrel (LNG) doses. Serum levels of EE, LNG, sex hormone-binding globulin and progesterone were compared in 41 obese [body mass index (BMI) ≥ 30] and 75 nonobese (BMI Results Suppression of ovulation during the luteal phase was dose dependent, with the highest dose (AG200-15) preventing progesterone increases in all women (cycles 2–3). In the follicular phase, the lowest-dose patch had the highest rate of increased progesterone in nonobese subjects. Progesterone levels ≥ 3.0 ng/mL in the follicular phase were more common in obese than nonobese women. Conclusions AG200-15 suppresses ovulation in obese and nonobese women. All three patches found increased progesterone in the follicular phase, albeit more in obese versus nonobese women.
United States space policy and international partnership

Abstract Has the current US space policy improved the USA's overall strategic position? Does it affect favorably international partnerships? These questions are examined in terms of security, political economy, and influence. In today's context, where there are more space players, more options, more potential for unintended consequences, and higher stakes, unilateral action is more limited in its effectiveness than in earlier times. Surveying current US space policy, it is not clear that data-driven, analytically based decisions are being made to affect positively national independence, innovation, market creation, and international perceptions of the USA as a trustworthy partner. More promising are the steps taken to bolster a predictable space operational environment and economic competitiveness. Ultimately, in order to achieve American excellence and leadership, a ‘closed loop’ on the policy system is needed, to gauge regularly and systematically whether the US is achieving the desired national outcomes.
Follicular placenta and embryonic growth of the viviparous four-eyed fish (Anableps)

In the four-eyed fish, Anableps (Atheriniformes, Anablepidae), eggs are fertilized and embryos develop to term within the ovarian follicles. Development is highly matrotrophic. During gestation, the largest term embryo of A. anableps examined had grown to a total length of 51 mm and attained a dry weight of 149 mg. The postfertilization weight increase is 298,000%. The largest term embryo of A. dowi examined had grown to a total length of 77 mm and attained a dry weight of 910 mg. The postfertilization weight increase is 843,000%. Embryonic weight increases result from nutrient transfer across the follicular placenta. This structure is formed by apposition of the maternal follicular epithelium to absorptive surface cells of the embryo's pericardial trophoderm. The latter, a ventral ramification of the pericardial somatopleure, replaces the yolk sac during early gestation. The external surface of the pericardial trophoderm develops hemispherical projections, termed vascular bulbs. Within each bulb, the vascular plexus of the trophoderm expands to form a blood sinus. Cells of the external surface of the bulbs possess microplicae. Microvilli are absent. During middle to late gestation, the juxtaembryonic follicular epithelium differentiates into two regions. One region consists of shallow, pitlike depressions within which vascular bulbs interdigitate in a "ball and socket" arrangement. Follicular pits are formed by the curvilinear distortion of the apical surfaces of follicle cells. The second region in contact with the dorsal and lateral surfaces of the embryo, is comprised of villous extensions of the hypertrophied follicular epithelium. In both regions, follicle cells appear to constitute a transporting rather than a secretory epithlium. In terms of percentage of weight increase, the follicular placenta of Anableps appears to be the most efficient adaptation for maternal-embryonic nutrient transfer in teleost fishes and closely approaches the efficiency (1.2 × 106 %) of oophagy and embryonic cannibalism in lamnoid sharks.
Effects of Global Constraints on Permissible Local Behavior

If two composition variables X and Y are sufficient to define both the thermodynamic and dynamic states of a system with acceptable accuracy, any such state can be represented by a point in a bounded region of the positive quadrant of the X-Y plane. Any stationary state within that region must belong to one of seven behavior classes, one of which is a double degeneracy that will probably never the encountered. The other six behavior classes are illustrated by well established models. Assignment of behavior class for a specific system can be made from the dynamic parameters for local behavior by using the signs and relative magnitudes of the trace and determinant of the secular equation. An entirely equivalent assignment can be made if two of the rate constants are replaced by the directions of the X and Y nullclines at the intersection which generates the stationary state. Although the secular equation is based solely on local behavior, the use of nullcline directions permits that local behavior to be impacted by global thermodynamic constraints. Such considerations show that the Lotka model with irreversible steps does not satisfy the thermodynamic constraints for a real chemical system, and only a very fortuitous combination of rate constants would permit the steady state to become the conservative center generated by the irreversible mechanism. The irreversible Brusselator model also fails to satisfy the thermodynamic constraints on a real chemical system, but the difficulty can be resolved by inclusion of reversibility. The irreversible Oregonator and Berlinator models satisfy the global constraints even with virtually no attention to reversibility.
Detection of myelin in the optic nerve of young rats by sedimentation equilibrium in a CsC1 gradient.

—A method is described for detecting myelin in small amounts of tissue by density criteria. Samples are homogenized in 0.926 m-CsCl, 10 mm-Tris-HCl, (pH 7.4), 5 mm-Ca2+ solution and centrifuged to equilibrium at 52,000 rev./min and 4°C in the AN-F rotor of the Model E analytical ultracentrifuge. Homogenates of white matter show a band of material in the density range of 1.20–1.130 g/ml, whereas gray matter homogenates do not show a band of material in this density region. A preparative method is described for isolating the material banding in the region of 1.120–1.130 g/ml from optic nerve homogenates of 21-day old rats. This material has (1) a protein content of 22–24%, (2) an enzymatic activity for 2′,3′-cyclic nucleotide phosphohydrolase of 13.1 μmol/min per mg protein and (3) a phospholipid-cholesterol-galactolipid molar ratio of 100:100:48. Plasmalogen accounted for 22% of the phospholipid, and sulfatide accounted for 31% of the galactolipid. This material is 85% soluble in chloroform:methanol (2:1. v:v). Developmental studies indicate that this myelin material can first be detected in the optic nerve from an 11-day-old rat.
Exact Relations between the Thermoelectroelastic Moduli of Heterogeneous Materials

Exact relations are obtained between the effective thermoelectroelastic moduli of two-phase heterogeneous media and their corresponding isothermal effective electroelastic moduli. The relations are obtained by generalizing the results of V. M. Levin, and B. W. Rosen and Z. Hashin to the inherently anisotropic coupling between the electric and elastic fields in thermoelectroelastic composites. The explicit expressions that are obtained can be used to obtain the effective thermal expansion and pyroelectric coefficients of the composite when the effective electroelastic (elastic, piezoelectric and dielectric) moduli are known, either by theory or experiment. The results also provide a means to assess the internal consistency of any micromechanics model that is proposed to estimate the thermoelectroelastic and electroelastic moduli of the composite. It is verified that when piezoelectric coupling is absent, the expressions reduce to those of B. W. Rosen and Z. Hashin for thermoelastic composite media. Finally, the resulting exact relations are exploited to prove the interesting phenomena that two-phase heterogeneous media can exhibit a net pyroelectric response even though neither of the individual phases exhibits pyroelectricity.
Design of resistive-input class E resonant rectifiers for variable-power operation

Resonant rectifiers have important application in very-high-frequency power conversion systems, including dc-dc converters, wireless power transfer systems, and energy recovery circuits for radio-frequency systems. In many of these applications, it is desirable for the rectifier to appear as a resistor at its ac input port. However, for a given dc output voltage, the input impedance of a resonant rectifier varies in magnitude and phase as output power changes. A design method is introduced for realizing single-diode “shunt-loaded” resonant rectifiers, or class E rectifiers, that provide near-resistive input impedance over a wide range of output power levels. The proposed methodology is demonstrated in simulation for a 10:1 power range.
Geometric Euler systems for locally isotropic motives

In this paper, we construct a theory of geometric Euler systems, complementary to the arithmetic theory of Rubin, Kato and Perrin-Riou. We show that geometric Euler systems can be used to prove the finiteness of certain Galois representations of weight zero and we discuss a conjectural framework for the existence of geometric Euler systems for motivic Galois representations. We give applications to adjoint Selmer groups of certain classical and Drinfeld modular forms.
Theoretical and experimental study of sawtooth effect in isolated cardiac cell-pairs.

Introduction The question of how a defibrillation shock affects the myocardium far (> approximately 1 mm; the space constant of continuum tissue models) from the electrode is not fully understood. According to a long-standing, yet to be verified, hypothesis, the relatively high-resistance intercellular gap junctions may help in coupling the shock effect to the distant myocardium by redistributing the defibrillation current and creating a sawtooth pattern of polarization in which every cell undergoes hyperpolarization and depolarization. The goal of this study was to conduct an in-depth theoretical and experimental investigation of the sawtooth effect in the simplest coupled system, that of an isolated cell-pair. Methods and results Theoretically, we present a relationship between sawtooth amplitude (STA) and junctional resistance (Rj), and show that, in a cell-pair with two cells of different lengths, the sawtooth effect may not necessarily appear as a reversal in polarization across the junction when Rj is below a critical value. Experimentally, we optically mapped transmembrane potential responses along the lengths of enzymatically isolated guinea pig cell-pairs at 10- or 17-microm resolution, and estimated STA as the magnitude of discontinuity in responses at the intercellular junction. From 14 cell-pairs, STA was estimated to be approximately 11 mV for a nominal 10 V/cm field. Based on our theoretical results, this value corresponds to an Rj of approximately 18 Mohms. Conclusion The intercellular junction induces a measurable sawtooth effect in the simplest system of an isolated cell-pair. An accounting for the sawtooth effect might be essential for understanding field-tissue interaction far from the electrode and to accurately predict tissue response during field stimulation.
Modeling the impact of product portfolio on the economic and environmental performance of recycling systems

Through the development of a general model of electronics recycling systems, the effect of product portfolio choices on economic and environmental system performance is explored. The general model encompasses the three main functions of a recycling system - collection, processing, and system management - and allows for the effect of both contextual and architectural inputs - including product scope - to be explored. Overall model results indicate that collecting a broader portfolio of products can be economically favorable, even for cases in which lower-value products are added to a recycling system. In these cases, the higher total mass throughputs that are realized by the collection of additional product types can help to drive down the cost per unit mass collected. Expanding product scope can also yield improvements in environmental performance, as the energy per unit mass collected can also decrease with higher mass throughputs.
Synthesis of modulated corrugated surface-wave structures

An exact procedure for the design of a surface that will support a prescribed group of surface waves simultaneously is described. The surfaces resulting from the application of this procedure are found to be modulated (i.e., to contain periodic waves in the direction of propagation) and to have surface impedance values that vary periodically in the direction of propagation. Finite-length surfaces of this type are hence reminiscent of Simon's "cigar antenna." Several surface designs are presented, and some general properties of the surfaces and the composite waves they support are discussed. Certain limitations on the design procedure are described.
Combined enhanced fluorescence and label-free biomolecular detection with a photonic crystal surface

A 2D photonic crystal surface with a different period in each lateral direction is demonstrated to detect biomolecules using two distinct sensing modalities. The sensing mechanisms both rely on the generation of a resonant reflection peak at one of two specific wavelengths, depending on the polarization of light that is incident on the photonic crystal. One polarization results in a resonant reflection peak in the visible spectrum to coincide with the excitation wavelength of a fluorophore, while the orthogonal polarization results in a resonant reflection peak at an infrared wavelength which is used for label-free detection of adsorbed biomolecules. The photonic crystal resonance for fluorescence excitation causes enhanced near fields at the structure surface, resulting in increased signal from fluorophores within 100 nm of the device surface. Label-free detection is performed by illuminating the photonic crystal with white light and monitoring shifts in the peak reflected wavelength of the infrared resonance with a high-resolution imaging detection instrument. Rigorous coupled-wave analysis was used to determine optimal dimensions for the photonic crystal structure, and devices were fabricated using a polymer-based nanoreplica molding approach. Fluorescence-based and label-free detection were demonstrated using arrays of spots of dye-conjugated streptavidin. Quantification of the fluorescent signal showed that the fluorescence output from protein spots on the photonic crystal was increased by up to a factor of 35, and deposited spots were also imaged in the label-free detection mode.
Thin-film circuit technology: Part II — Thin-film superconducting devices

Thin-film techniques have contributed significantly to an improved understanding of superconductivity. Cryogenic thin films are particularly suitable for use in switching and storage devices in computer memories
Subcarrier allocation in OFDMA systems: beyond water-filling

This paper considers the issue of optimal subcarrier allocation in OFDMA. When including time-varying packet arrivals and channels, we show, via a counter example, that water-filling-based subcarrier allocation policies, contrary to conventional wisdom, fail to provide rate-stability for an otherwise stabilizable OFDMA system. We briefly discuss the long-run throughput optimality in OFDM as demonstrated in (S. Kittipiyakul et al., 2004). In particular under a simple channel model, we consider a nonidling policy which balances the queues and outperforms water-filling policies by achieving the minimum average delay. In this paper, we provide simple computation algorithms for implementing such policies and provide simulations for a numerical comparative study.
Physical modalities in chronic pain management.

The following conclusions can be made based on review of the evidence: There is limited but positive evidence that select physical modalities are effective in managing chronic pain associated with specific conditions experienced by adults and older individuals. Overall, studies have provided the most support for the modality of therapeutic exercise. Different physical modalities have similar magnitudes of effects on chronic pain. Therefore, selection of the most appropriate physical modality may depend on the desired functional outcome for the patient, the underlying impairment, and the patient's preference or prior experience with the modality. Certain patient characteristics may decrease the effectiveness of physical modalities, as has been seen with TENS. These characteristics include depression, high trait anxiety, a powerful others locus of control, obesity, narcotic use, and neuroticism. The effect on pain by various modalities is generally strongest in the short-term period immediately after the intervention series, but effects can last as long as 1 year after treatment (e.g., with massage). Most research has tested the effect of physical modalities on chronic low back pain and knee OA. The effectiveness of physical modalities for other chronic pain conditions needs to be evaluated more completely. Older and younger adults often experience similar effects on their perception of pain from treatment with physical modalities. Therefore, use of these modalities for chronic pain in older adults is appropriate, but special precautions need to be taken. Practitioners applying physical modalities need formal training that includes the risks and precautions for these modalities. If practitioners lack formal training in the use of physical modalities, or if modality use is not within their scope of practice, it is important to consult with and refer patients to members of the team who have this specialized training. Use of a multidisciplinary approach to chronic pain management is of value for all adults and older individuals in particular [79-81]. Historically, physical therapists have been trained to evaluate and treat patients with the range of physical modalities discussed in this article. Although members of the nursing staff traditionally have used some of these modalities (e.g. some forms of heat or cold and massage), increasing numbers of nurses now are being trained to apply more specialized procedures (e.g., TENS). Healthcare professionals must be knowledgeable about the strength of evidence underlying the use of physical modalities for the management of chronic pain. Based on the limited research evidence available (especially related to assistive devices, orthotics, and thermal modalities), it often is difficult to accept or exclude select modalities as having a potential role in chronic pain management for adults and older individuals. Improved research methodologies are needed to address physical modality effectiveness better.
Gravimetric chemical sensor based on the direct integration of SWNTS on ALN Contour-Mode MEMS resonators

This paper reports on the first demonstration of a gravimetric chemical sensor based on direct integration of single wall carbon nanotubes (SWNTs) grown by chemical vapor deposition (CVD) on AIN contour-mode MicroElectroMechanical (MEMS) resonators. In this first prototype the ability of SWNTs to readily adsorb volatile organic chemicals has been combined with the capability of AIN Contour-Mode MEMS resonator to provide for different levels of sensitivity due to separate frequencies of operation on the same die. Two devices with resonance frequencies of 287 MHz and 442 MHz have been exposed to different concentrations of DMMP in the range from 80 to 800 ppm. Values of mass sensitivity equal to 1.8 KHz/pg and 2.65 KHz/pg respectively have been measured.
Improved finite difference formulas for boundary value problems

This paper deals with the numerical solution of linear differential equations of fourth order by finite differences. It points out significant (but usually overlooked) errors which result from the conventional method of imposing the boundary conditions in such problems. Revised finite difference formulas are derived which apply near the boundaries and which eliminate the above errors. Three commonly encountered boundary conditions ar econsidered. These correspond, in the terminology of beam analysis, to a clamped end, to a simply supported end and to a free end. The improvement in accuracy that can be achieved with the revised formulas is illustrated by two representative examples. The revised formulas are shown to reduce the overall error of the numerical solution by a factor of about five in a typical case.
Towards a better understanding of software evolution: An empirical study on open source software

Software evolution is a fact of life. Over the past thirty years, researchers have proposed hypotheses on how software changes, and provided evidence that both supports and refutes these hypotheses. To paint a clearer image of the software evolution process, we performed an empirical study on long spans in the lifetime of seven open source projects. Our analysis covers 653 official releases, and a combined 69 years of evolution. We first tried to verify Lehman's laws of software evolution. Our findings indicate that several of these laws are confirmed, while the rest can be either confirmed or infirmed depending on the laws' operational definitions. Second, we analyze the growth rate for projects' development and maintenance branches, and the distribution of software changes. We find similarities in the evolution patterns of the programs we studied, which brings us closer to constructing rigorous models for software evolution.
A scalable silicon microreactor for preferential CO oxidation: performance comparison with a tubular packed-bed microreactor

PEM fuel cells utilizing hydrogen and oxygen have shown great promise as future sources of clean, efficient power. Due to difficulties encountered in hydrogen storage and transport, investigation of on-board generation of hydrogen via fuel processing of liquid hydrocarbons has gained prominence. To achieve these goals, the need for compact reactor systems with effective component and heat integration as well as quick start-up times has been observed. This paper underlines the suitability of microreaction technology for the development of compact fuel processing systems as compared to packed-bed reactor technology which does not scale down in a feasible manner. A microchannel reactor was fabricated in silicon using standard microfabrication tools. A 2% Pt/Al2O3 catalyst was washcoated on the channel walls. Preferential CO oxidation in H2 was chosen as a model reaction and the results were compared with those obtained from a conventional packed-bed microreactor. The silicon microreactor performs very well, while offering distinct advantages such as flexibility of reactor design, integration of structural and functional features and low pressure drop. Use of a wall-coated catalyst as compared to a packed-bed catalyst does not introduce any loss of performance efficiency due to external diffusive limitations. Issues of scale-up and efficient heat integration have also been addressed. # 2004 Elsevier B.V. All rights reserved.
Modeling and predicting complex space–time structures and patterns of coastal wind fields

A statistical technique is developed for wind field mapping that can be used to improve either the assimilation of surface wind observations into a model initial field or the accuracy of post-processing algorithms run on meteorological model output. The observed wind field at any particular location is treated as a function of the true (but unknown) wind and measurement error. The wind field from numerical weather prediction models is treated as a function of a linear and multiplicative bias and a term which represents random deviations with respect to the true wind process. A Bayesian approach is taken to provide information about the true underlying wind field, which is modeled as a stochastic process with a non-stationary and non-separable covariance. The method is applied to forecast wind fields from a widely used mesoscale numerical weather prediction (NWP) model (MM5). The statistical model tests are carried out for the wind speed over the Chesapeake Bay and the surrounding region for 21 July 2002. Coastal wind observations that have not been used in the MM5 initial conditions or forecasts are used in conjunction with the MM5 forecast wind field (valid at the same time that the observations were available) in a post-processing technique that combined these two sources of information to predict the true wind field. Based on the mean square error, this procedure provides a substantial correction to the MM5 wind field forecast over the Chesapeake Bay region. Copyright © 2005 John Wiley & Sons, Ltd.
Address-branch correlation: A novel locality for long-latency hard-to-predict branches

Hard-to-predict branches depending on long-latency cache-misses have been recognized as a major performance obstacle for modern microprocessors. With the widening speed gap between memory and microprocessors, such long-latency branch mispredictions also waste substantial power/energy in executing instructions on wrong paths, especially for large instruction window processors. This paper presents a novel program locality that can be exploited to handle long-latency hard-to-predict branches. The locality is a result of an interesting program execution behavior: for some applications, major data structures or key components of the data structures tend to remain stable for a long time. If a hard-to-predict branch depends on such stable data, the address of the data rather than the data value is sufficient to determine the branch outcome. This way, a misprediction can be resolved much more promptly when the data access results in a long-latency cache miss. We call such locality address-branch correlation and we show that certain memory-intensive benchmarks, especially those with heavy pointer chasing, exhibit this locality. We then propose a low-cost auxiliary branch predictor to exploit address-branch correlation. Our experimental results show that the proposed scheme reduces the execution time by 6.3% (up to 27%) and energy consumption by 5.2% (up to 24%) for a set of memory-intensive benchmarks with a 9 kB prediction table when used with a state-of-art 16 kB TAGE predictor.
Altitude variations in the thermosphere mass density response to geomagnetic activity during the recent solar minimum

Accelerometer data from coplanar orbits of Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites were used to study the complex altitude and latitude variations of the thermosphere mass density response to geomagnetic activity during 1–10 December 2008 near 09 LT. Helium number densities near 500 km altitude were extracted from the CHAMP and GRACE measurements and clearly show the presence of a winter hemisphere helium bulge. This recent extreme solar minimum indicates that wintertime helium concentrations exceed NRLMSISE-00 model estimates by 30%–70% during quiet geomagnetic activity after adjusting F10.7 input into MSIS. The perturbation in mass density from quiet to active conditions is found to be less enhanced in the winter hemisphere at the higher GRACE altitudes (25%) than at the lower CHAMP altitudes (60%) and is attributed to dynamic behavior in the helium/oxygen transition. The investigation revealed the maximum storm time density perturbation to occur near the He/O transition region with a much weaker maximum near the O/N2 transition region. The altitude of maximum density perturbation occurs where the perturbation in the weighted pressure scale height is equal and opposite to the perturbation in the weighted mean molecular weight scale height. The altitude structure of density scale height perturbation is significantly influenced by the changes in the molecular weight scale height and can account for 50% of the change in mass density scale height in a region correspondingly close to the He/O transition during the 2008 solar minimum period.
Signals from the Past

Science’s STKE celebrates Science’s 125th anniversary issue by presenting 12 notable articles from Science that highlight different aspects of cell signaling research.
The simplex method for integral multicommodity networks

The simplex method is interpreted as a labeling procedure for certain classes of multicommodity flow problems in a manner similar to that for single commodity networks. As opposed to general multicommodity algorithms, no explicit matrix inversion is required; all simplex operations are performed graph-theoretically.