cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular Determinants of Partial agonist Affinity in Adult Neuromuscular Acetylcholine Receptors

Adult neuromuscular acetylcholine receptor-channels have two agonist binding sites located at α-δ and α-e subunit interfaces. In α, W149, Y190, and Y198 (known as the aromatic ‘triad’) are the main determinants of acetylcholine affinity (Purohit et al., 2012). Ligands resembling the components of ACh, tetramethylammonium (TMA) and choline (Cho), are partial agonists. It is unknown what interactions at the binding site distinguish full vs. partial agonists. We used single-channel electrophysiology to estimate the binding energy (resting affinity) of mutants of the triad and non-α residues eY104/δY106, eS117/δT119 and eL119/δL121 activated by partial agonists. All triad mutations weakened the affinity of the 3 agonists, in the order of αY190>αW149≈αY198. αY190F produced the same, large reduction in affinity for ACh, TMA, Cho and 3 other choline derivatives. Dissimilarities between agonists were observed with αW149F and triad Ala mutants. ACh affinity depends on the type of aromatic residue at position 149, but not Cho. The removal of the aromatic group (to Ala) had a greater effect on ACh and TMA vs. Cho. The smaller change in binding energy of Cho with αW149 mutants is consistent with the hypothesis that Cho forms an H-bond with the αW149 backbone (Bruhova et al., 2013). On the non-α subunits, eY104/δY106 mutations (A, S and L) enhanced ACh, TMA and Cho affinities, but eS117/δT119 or eL119/δL121 mutations weakly reduced affinity. The role of eY104 is explained by a molecular model in which eY104 π-stacks with αW149 to weaken the interaction of this indole with the agonist's quaternary amine. In agreement, experiments showed strong energy coupling in the double mutant eY104A-αW149A. This also explains, in part, why the fetal receptor containing a Leu at γY104 has a higher affinity for ACh and Cho. Supported by CIHR and NS-64969.
An evolutionary algorithm approach for the constrained multi-depot vehicle routing problem

– The purpose of this paper is to explore a real world vehicle routing problem (VRP) that has multi-depot subcontractors with a heterogeneous fleet of vehicles that are available to pickup/deliver jobs with varying time windows and locations. Both the overall job completion time and number of drivers utilized are analyzed for the automated job allocations and manual job assignments from transportation field experts. , – A nested genetic algorithm (GA) is used to automate the job allocation process and minimize the overall time to deliver all jobs, while utilizing the fewest number of drivers – as a secondary objective. , – Three different real world data sets were used to compare the results of the GA vs transportation field experts’ manual assignments. The job assignments from the GA improved the overall job completion time in 100 percent (30/30) of the cases and maintained the same or fewer drivers as BS Logistics (BSL) in 47 percent (14/30) of the cases. , – This paper provides a novel approach to solving a real world VRP that has multiple variants. While there have been numerous models to capture a select number of these variants, the value of this nested GA lies in its ability to incorporate multiple depots, a heterogeneous fleet of vehicles as well as varying pickup times, pickup locations, delivery times and delivery locations for each job into a single model. Existing research does not provide models to collectively address all of these variants.
The effect of trimethoprim on potassium and uric acid metabolism in normal human subjects.

Background: Trimethoprim used in combination with other antibiotics, has been implicated in causing hyperkalemia and hypouricemia in patients with acquired immune deficiency syndrome (AIDS). In experimental animal models, trimethoprim has been demonstrated to block sodium channels and Na + -K + -ATPase in the distal nephron and thus impair potassium excretion. Although the data from the experimental models suggest that trimethoprim reduces urinary potassium excretion, the retrospective clinical studies have confounding factors that prevent a rigorous demonstration that the hyperkalemia and hypouricemia are due solely to the effects of trimethoprim on solute excretion. Aim: The purpose of this study was to evaluate the effect of trimethoprim on potassium and uric acid balance in normal human subjects. Methods: Five normal human subjects were admitted to the general clinical research center and placed on a fixed metabolic diet. After a 4-day control period, the subjects were given trimethoprim (15 mg/kg/day) orally for 5 - 7 days followed by a 4-day recovery period. Free-flow blood samples and 24-hour urine collections were obtained daily. Results: Treatment with trimethoprim resulted in a significant increase in plasma potassium concentration (4.5 ± 0.1 versus 3.7 ± 0.1 mmol/l, p < 0.005) and significant decrease in serum uric acid concentration (3.8 ± 0.4 versus 5.6 ± 0.5 mg/dl, p < 0.001). Treatment with trimethoprim significantly increased the urinary excretion of uric acid, but did not significantly decrease potassium excretion during the 7-day treatment period. There was, however, a significant decrease in potassium excretion observed during the first 48 hours of trimethoprim treatment. In one subject where repeat studies were performed using different dosages, the effect on potassium and uric acid levels appeared to be dose-dependent. Conclusions: Trimethoprim increases plasma potassium concentration probably by reducing urinary potassium excretion. Trimethoprim decreases serum uric acid levels by augmenting urinary uric acid excretion. This uricosuric effect may be due to the ability of trimethoprim to impair urate reabsorption by the urate-anion exchanger in the proximal tubule.
Rett syndrome and MECP2-related disorders

Abstract Rett syndrome (RTT) is a severe neurodevelopmental disorder characterized by loss of spoken language and hand use, characteristic repetitive hand stereotypies, and gait problems. RTT is usually caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). Extensive work has been performed to understand how MeCP2 dysfunction affects cells, circuits, physiology, and behavior. Promisingly, restoration of MeCP2 expression in symptomatic RTT mice reverses clinical phenotypes, suggesting that the disease will be modifiable if not fully reversible. This chapter reviews clinical features of RTT, the current understanding of the molecular, cellular, and circuit role of MeCP2, and approaches to therapy.
Histidine phosphorylation relieves copper inhibition in the mammalian potassium channel KCa3.1

KCa2.1, KCa2.2, KCa2.3 and KCa3.1 constitute a family of mammalian small- to intermediate-conductance potassium channels that are activated by calcium-calmodulin. KCa3.1 is unique among these four channels in that activation requires, in addition to calcium, phosphorylation of a single histidine residue (His358) in the cytoplasmic region, by nucleoside diphosphate kinase-B (NDPK-B). The mechanism by which KCa3.1 is activated by histidine phosphorylation is unknown. Histidine phosphorylation is well characterized in prokaryotes but poorly understood in eukaryotes. Here, we demonstrate that phosphorylation of His358 activates KCa3.1 by antagonizing copper-mediated inhibition of the channel. Furthermore, we show that activated CD4(+) T cells deficient in intracellular copper exhibit increased KCa3.1 histidine phosphorylation and channel activity, leading to increased calcium flux and cytokine production. These findings reveal a novel regulatory mechanism for a mammalian potassium channel and for T-cell activation, and highlight a unique feature of histidine versus serine/threonine and tyrosine as a regulatory phosphorylation site.
The Limits of Conventional Economics

The last century has seen the ascendancy, indeed intellectual dominance, of neoclassical economics (NCE, also known as market or Walrasian or University of Chicago or, Washington consensus or, occasionally, neo welfare economics). The basic neoclassical model represents the economy as a self-maintaining circular flow among firms and households, driven by the psychological assumptions that humans act principally in a materialistic, self-regarding, and predictable way. Unfortunately the NCE model violates a number of physical laws and is inconsistent with actual human behavior. Consequently the NCE model is unrealistic and a poor predictor of people’s actions, as an array of experimental and physical evidence and recent theoretical breakthroughs demonstrate. Despite the abundance and validity of these critiques, few economists seriously question the neoclassical paradigm that forms the foundation of their applied work. This is a problem because policy makers, scientists, and others turn to economists for answers to important policy questions. The supposed ­virtues of “privatization,” “free markets,” ­“consumer choice,” and “cost–benefit analysis” are considered to be self-evident by most practicing economists, as well as many in business and government. In fact the evidence that these concepts are correct or do what most people believe they do is rather slim and contradictory. Thus this chapter is a strong critique of economic theory, in this case NCE [1].
Mutations in the c-fes locus associated with colon cancer inhibit Fes protein-tyrosine kinase activity and suggest a novel role as a tumor suppressor

Proc Amer Assoc Cancer Res, Volume 45, 2004 3929 The human c-fes locus encodes a 93 kDa protein-tyrosine kinase implicated in the differentiation of neuronal, endothelial and myeloid hematopoietic cells. Recent global sequence analysis of 133 protein-tyrosine kinase (PTK) and PTK-like genes in colorectal cancers identified Fes as one of only six PTK genes with mutations in more than one tumor (Bardelli et al. Science 300:949, 2003). Although four mutations were observed within the Fes kinase domain (M704V, R706Q, V743M, S759F), the consequences of these mutations on kinase activity have not been explored. To address this issue, Fes mutants with these substitutions were over-expressed in human 293T cells and kinase activity was assessed via immunoblot analysis with a phosphospecific antibody against the activation loop phosphotyrosine (Tyr 713). Surprisingly, M704V, R706Q, and V743M all substantially reduced basal autophosphorylation compared to wild-type Fes, while S759F had no effect on kinase activity. The R706Q and S759F mutants were also combined with an activating mutation (L145P) and expressed in S. cerevisiae. R706Q completely reversed the activating effect of L145P in yeast, indicating that this mutation inhibits Fes activity by affecting kinase structure independent of the mammalian cell context. The S759F mutation was without effect, consistent with the result in mammalian cells. The observations that all four colon cancer-associated mutations failed to activate Fes and in three cases blocked kinase activity suggest a role for Fes as a tumor suppressor rather than a dominant oncogene in colon cancer. To test this hypothesis, wild-type and mutant forms of Fes were stably expressed in the human colorectal adenocarcinoma cell line HT-29, and anchorage-independent growth was assessed using a soft agar assay. Expression of wild-type or kinase-defective Fes had little impact on soft-agar colony formation by HT-29 cells, consistent with the lack of kinase activity observed with these proteins on anti-phosphotyrosine immunoblots. However, expression of each of three different kinase-active forms of Fes dramatically reduced HT-29 cell soft-agar colony numbers and size. Moreover, endogenous Fes protein expression was undetectable by immunoblot analysis in parental HT-29 cells, suggesting that loss of Fes expression, like the inactivating mutations described here, may contribute to transformation. Our findings that c-fes mutations associated with colon cancer fail to activate and in most cases inhibit Fes kinase activity, together with direct evidence that kinase-active forms of Fes suppress HT-29 tumor cell growth, strongly implicate Fes as a tumor suppressor in colorectal cancer.
British Women Writers and the Reception of Ancient Egypt, 1840-1910

Florence Nightingale called her trip to Egypt a “spiritual and intellectual whirlwind.” Arrival in the country spurred her to flights of enthusiasm and religious fantasy, and yet it also unsettled ...
Rate of Liquid Entrainment at the Gas-Liquid Interface of a Liquid Submerged Sonic Gas Jet

A model is presented describing the phenomenon of liquid entrainment resulting from the presence of Kelvin-Helmholtz instability at the gas-liquid interface of a sonic gas jet submerged in a mass o...
Genome-Scale Modeling of NADPH-Driven β-Lapachone Sensitization in Head and Neck Squamous Cell Carcinoma.

Abstract Aims: The purpose of this study was to investigate differential NADPH production between radiation-sensitive and -resistant head and neck squamous cell carcinoma (HNSCC) cell lines and whether these differences are predictive of sensitivity to the chemotherapeutic β-lapachone. Results: We have developed a novel human genome-scale metabolic modeling platform that combines transcriptomic, kinetic, thermodynamic, and metabolite concentration data. Upon incorporation of this information into cell line-specific models, we observed that the radiation-resistant HNSCC model redistributed flux through several major NADPH-producing reactions. Upon RNA interference of canonical NADPH-producing genes, the metabolic network can further reroute flux through alternate NADPH biosynthesis pathways in a cell line-specific manner. Model predictions of perturbations in cellular NADPH production after gene knockdown match well with experimentally verified effects of β-lapachone treatment on NADPH/NADP+ ratio and cell...
It is in the Contract: How the Policies Set in Teachers’ Unions’ Collective Bargaining Agreements Vary Across States and Districts:

We examine more than 1,000 collective bargaining agreements (CBAs) in place across California, Michigan, and Washington. We investigate the prevalence of a set of 43 key provisions between and within these states, providing the first comprehensive comparison of CBA terms using data drawn from economically and demographically different districts, as well as districts that vary considerably by student enrollment. We find that CBAs vary substantially within and across states, and that this variation is more associated with district size than the proportion of low-income students within districts. We conclude by discussing the implications of these findings for research and policy.
Electrocatalysis over Graphene-Defect-Coordinated Transition-Metal Single-Atom Catalysts

The family of single-atom catalysts dispersed in defective graphene matrices are now of increasing interest for a wide range of reactions given their tunable coordination environments and electronic structures. In this issue of Chem, Yao and co-workers demonstrate atomic Ni@graphene catalysts for water splitting via different active motifs.
Regarding minimal clinically relevant differences for superiority margins.

Being familiar with the relevant previous work of authors Shafiq and Malhotra, I read with interest their recent letter with Gamad concerning reporting of the Canakinumab Anti-Inflammatory Thrombosis Outcome Study (CANTOS).1 That trials such as CANTOS continue to be reported with claims of superiority without consideration of asymmetry in error margins …
Distributed battery system with wireless control and power transfer — A concept introduction

The paper introduces the concept of a battery system or pack architecture that is divided into several battery modules that share the load power wirelessly and are controlled wirelessly. Each of the wireless battery modules includes its own power electronics for DC-AC power conversion for Wireless Power Transfer (WPT), regulation of voltage and State-Of-Charge (SOC), and wireless communication link with an on-board unit. The on-board unit combines the power received wirelessly from all of the battery modules (AC-DC or AC-AC conversion) and its master controller uses the voltage, current, and other information received wirelessly from the battery modules to wirelessly send back control commands in order to regulate the discharge (or charge) rate of each battery module. For example, in the Electric Vehicles (EVs) application this wirelessly controlled and distributed battery system or pack can potentially allow for exchanging or swapping the wireless battery modules in a safer, easier, and faster manner. This can potentially contribute to significantly reduced “Range Anxiety” phenomenon that is associated with EVs.
Essential metals in oral contraceptive tablets.

Many pharmaceutical preparations contain varying amounts of substances, usually metals, which remain as a by-product of preparation. Eleven diferent types of oral contraceptives were analyzed for their essential content of sodium, potassium, calcium, magnesium, iron, copper, and zinc. Several brands of tablets contained significant quantities of calcium, but only very small quantities o f the other metals.
A randomized controlled clinical trial assessing the effect of betamethasone valerate 0.12% foam on the short-term treatment of stasis dermatitis.

Background: There are no published studies examining either the effectiveness of topical steroids in the treatment of stasis dermatitis or indicating what steroid strength or duration of treatment is optimal to treat thiscommon condition. Objective: To investigate the efficacy of twice-daily application of the topical steroid betamethasone valerate 0.12% foam for the treatment of stasis dermatitis. Design: 42-day randomized, double-blinded, vehicle-controlled, pilot study. Settings: Outpatient dermatology clinic at a university-affiliated clinic. Subjects: 19 subjects, mean age of 73, with mild to moderate bilateral stasis dermatitis. Intervention: Twice-daily application of betamethasone valerate 0.12% foam versus vehicle foam to bilateral randomly assigned lower legs for 28 days with follow-up to day 42. Main Outcome Measures: The primary clinical endpoints were the mean change in erythema, scale, swelling, petechiae, post-inflammatory hyperpigmentation, and self-reported pruritus, assessed on a 5-point Likert scale (0 = clear, 1 = almost clear, 2 = mild, 3 = moderate, 4 = severe). Secondary endpoints were changes in health related quality of life (HRQL) using the EuroQol-5D (EQ-5D) utility score and visual analog scale (VAS) and the Dermatology Life Quality Index (DLQI). Results: Although there was no overall difference between the foam and vehicle-treated leg at days 14 and 28, the steroid-treated leg, but not the vehicle-treated leg, showed statistical improvement over baseline. Improvement in the steroid-treated leg was statistically better than vehicle at days 14 and 28 in terms of erythema (P <.05) and petechiae (P <.05). Improvement in VAS was notable at days 14 (7.1%), 28 (9.7%), and 42 (9.6%) (P <.001). Similarly, there was a statistically significant improvement in the DLQI compared to baseline on visit days 14 (188.9%) and 28 (126.1%) (P<.001). Conclusions: This study suggests that betamethasone valerate 0.12% foam is an effective and well-tolerated short-term treatment of stasis dermatitis, but that higher potency steroids may be needed to achieve better efficacy. Furthermore, these results are the first to suggest that the application of effective topical anti-inflammatory therapy can lead to improvement in HRQL.
Obesity increases airway smooth muscle responses to contractile agonists.

The asthma-obesity syndrome represents a major public health concern that disproportionately contributes to asthma severity and induces insensitivity to therapy. To date, no study has shown an intr...
Television News Repertoires, Exposure Diversity, and Voting Behavior in the 2016 U.S. Election:

This study explores the television news repertoires and voting behaviors of American citizens in the 2016 U.S. election. The results reveal notably different repertoires, some defined by ideologica...
Psychophysiological Arousal and Perceived Support during Couple Support Interactions: The Role of Attachment Anxiety and Avoidance

Couple support processes—typically occurring in the context of non-relationship distressing issues—are crucial to our understanding of relationships (Pasch, Bradbury, & Sullivan, 1997). These coupl...
Roses from the Cracks: A Pedagogical Reflection on the 2018 Religious Education Association Annual Meeting.

AbstractThis essay explores what surfaces when we lead a reflection on the 2018 REA meeting with questions about teaching and learning. What pedagogical models appeared to be operative during the m...
Directed self-placement as a tool to foreground student agency

Abstract This review examines directed self-placement, a placement tool that provides students with information about curricular options and asks each student to self-select into any first-year writing course. Specific constructs of a given directed self-placement approach vary from institution to institution; in this review we work to synthesize a diverse range of available scholarship to describe the common features of and beliefs implicit in this placement tool. While directed self-placement is a promising option for institutions seeking to better empower students in the placement process, we draw attention to the need for locally specific modifications and the opportunities for future research on how directed self-placement can be made a more valid and equitable practice.
Utilizing Charge Effects and Minimizing Intramolecular Proton Rearrangement to Improve the Overpotential of a Thiosemicarbazonato Zinc HER Catalyst.

The zinc(II) complex of diacetyl-2-(4-methyl-3-thiosemicarbazone)-3-(2-hydrazonepyridine), ZnL1 (1), was prepared and evaluated as a precatalyst for the hydrogen evolution reaction (HER) under homo...
(Ultra)Wide-Bandgap Vertical Power FinFETs

FinFET is the backbone device technology for CMOS electronics at deeply scaled technology nodes per Moore’s law. Recently, the FinFET concept has been leveraged to develop a new generation of vertical power transistors based on wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors for kilovolts and high-power applications. The sidewall gate-stack in a vertical power FinFET can rely on either a metal–oxide–semiconductor (MOS) structure or a p-n junction, rendering a Fin-MOSFET or a fin-based junction field-effect transistor (Fin-JFET), respectively. Although the device technologies are still at the early stage of development, 1.2-kV-class WBG gallium nitride (GaN) power Fin-MOSFETs have demonstrated one of the highest static and switching performances in all similarly rated power transistors; UWBG gallium oxide power Fin-MOSFETs have shown high performance up to a breakdown voltage over 2.6 kV. Early UWBG diamond lateral power Fin-MOSFETs have also been demonstrated. Meanwhile, GaN power Fin-JFETs are currently under active development. This article provides a comprehensive tutorial and review of the background and recent advances in WBG and UWBG vertical power FinFETs. It covers fundamental device physics, device and process development, as well as the static and switching performance of various power Fin-MOSFETs and Fin-JFETs. This article is concluded by identifying the current challenges and exciting research opportunities in this very dynamic research field.
Flexible Recruitment of Balance Mechanisms to Environmental Constraints During Walking

Background: Humans need to actively control their upright posture during walking to avoid loss of balance. We do not have a comprehensive theory for how humans regulate balance during walking, especially in complex environments. The nervous system must process many aspects of the environment to produce an appropriate motor output in order to maintain balance on two legs. We have previously identified three balance mechanisms that young healthy adults use to maintain balance while walking: 1) The ankle roll mechanism, a modulation of ankle inversion/eversion; 2) The foot placement mechanism, a shift of the swing foot placement; and 3) The push-off mechanism, a modulation of the ankle plantar flexion angle during double stance. We know that these mechanisms are inter dependent and can be influenced by internal factors such as the phase of the gait cycle and walking cadence. Here we seek to determine whether there are changes in neural control of balance when walking in the presence of environmental constraints. Methods: Subjects walked on a self-paced treadmill while immersed in a virtual environment that provides three different colored pathways. Subjects were instructed not to step in the No-Step Zone, which appeared either on the right or left side of the subject. While walking, subjects received balance perturbations in the form of galvanic vestibular stimulation,providing the sensation of falling sideways, either toward the No-Step zone or toward the Neutral zone on the other side. Results: The results indicate that the use of the balance mechanisms are altered depending on whether the perceived fall is toward the No-Step or the Neutral zone. Participants increased the use of the lateral ankle and foot placement mechanisms for No-Step stimuli resulting in a larger shift of the center of mass (CoM) compared to the Neutral stimuli. Conclusion:This experiment provides further evidence that the balance control system during walking is extremely flexible, recruiting multiple mechanisms at different times in the gait cycle to adapt to environmental constraints.
Cooperative Communication Between Two Transiently Powered Sensor Nodes by Reinforcement Learning

Energy harvesting (EH) powered sensor nodes can achieve theoretically unlimited lifetime by scavenging energy from ambient power sources, such as radio frequency (RF) and kinetic energy. The nodes can collect and transmit data wirelessly with the harvested energy. However, the transmission between two sensor nodes is successful only when both nodes have enough energy at the same time. While the receiver can be actively listening, it may deplete the energy long before the sender has accumulated enough energy. Thus, given the scarce, unpredictable, and unevenly distributed energy among sensor nodes, it is challenging to ensure efficient data transmission between them. To address this challenge, we propose a sensor node architecture with multiple radios, each with different energy consumption on the sender and receiver. A node can be put into sleep when charged up and wakes up for communication when it infers that both nodes have enough energy based on its observations. What is more, two nodes can cooperatively and dynamically select different radios according to the stored energy and historical information to maximize the data throughput. To achieve cooperative communication adaptively, the communication procedure is modeled as a cooperative Markov game with partial observability on each node, and multi-agent reinforcement learning (MARL) is employed to achieve the best results. Experimental results on hardware prototype and by simulation show that the proposed approaches achieve up to 89.1% of the optimal throughput and significantly outperform other online algorithms.
Social Networks in Fifth Grade Classrooms: Who Reports being in a Group and Who Does Not?

The present study examined the behavioral and affiliative differences between 2403 fifth grade students (1307 female, 1096 male) who reported that they belonged to a social group on social cognitive map (SCM) procedures and those who did not even though their peers viewed them as members of a peer group. Students who did not report their affiliations were more often classified as victims of bullying, have lower peer preference, have more peer-assessed internalizing symptoms, and have lower prosocial behavior and social prominence than students who reported their peer affiliates. Females with higher self-reported levels of aggression were more likely to report their peer affiliations. Males with higher self-reported levels of internalizing symptoms were less likely to report their affiliations. Implications and future directions are discussed.
Size Anomalies in U.S. Bank Stock Returns and Banking Reforms

Using unique data on over-the-counter bank stock prices and balance sheet information we explore bank funding cost differentials using the risk-adjusted return gap between the largest and the smallest depository institutions. We find that the largest commercial bank stocks, ranked by market value or gross deposits, have significant lower risk-adjusted annual returns than do small sized bank stocks even after controlling for standard risk factors including size. This return difference is one of the first instances of preferential treatment for large banks and can be attributed to the Banking Act of 1935 which authorized the FDIC to act as the liquidator for all insured banks, and to choose which bank would be resolved by purchase and assumption and which by liquidation. Failures of larger institutions tended to be resolved by purchase and assumption, which is preferred because it preserves the value of the going concern, while failures of smaller institutions tended to be resolved by payoff and liquidation. When examined during the period of 1926 to 1939, when there are no such guarantees, we do not find any risk-adjusted returns differences between different sizes of banks.
Imaging Features of Chondrosarcoma

Chondrosarcoma is a malignant tumor of hyaline cartilage. It can be classified as primary or secondary (arising from a benign osteochondroma or enchondroma). Primary chondrosarcoma is the third most common primary malignant tumor of the bone. Chondrosarcoma can be further divided into different subtypes that include central, clear cell, periosteal, mesenchymal, myxoid, and dedifferentiated. This chapter will review the imaging features of these various subtypes.
Piezoelectric bimorphs with quadratic behavior using biased ZnO on Si/sub 3/N/sub 4/

Piezoelectric bimorphs have been made by sputtering ZnO on Si/sub 3/N/sub 4/. The ZnO was sandwiched between Cr/Au electrodes. Bimorphs 1688- and 2980- mu m long were produced. The frequency dependence of the tip deflection of the bimorphs was measured. It was observed that the deflection increases with biasing voltage, as was to be expected from static deflection measurements. >
Modeling considerations in static and dynamic voltage stability studies of shipboard power systems

Better modeling is a key issue to system analysis and emulating real system performances accurately. This paper addresses modeling considerations and approaches to be taken for voltage stability analysis. Two approaches, static and dynamic analysis, are often applied in voltage stability studies, static for small disturbance and dynamic for large disturbance. The characteristics of main power system components, such as generators, loads, transmission and distribution networks in both approaches have been discussed. Modeling approaches presented here will be extended to the Shipboard Power System (SPS). IEEE 9-bus test system is used to illustrate the procedures of a static approach. Three-phase and twelve-phase synchronous generators are taken as examples to explain the numerical integration method in dynamic modeling and validation. The time-domain simulation is performed to verify the generator modeling in PSCAD.
HIV and AIDS in Africa: Compulsory Licensing Under TRIPS and DOHA Declaration

In today’s world, there is a lot of focus on issues such as militancy, global warming, terrorism, racism and even politics. Unfortunately, there is a problem that has killed and is still killing far more people than any of the above issues. That problem is HIV/AIDS.AIDS is a serious medical condition that predisposes patients towards opportunistic infecting tumors, dementia and death. HIV is the viral agent associated with AIDS. Ensuring continued access to affordable antiretroviral (ARVs) medicines is vital for the survival of patients due to the fact that ARVs can slow down and reverse the progression of HIV infection, subsequently delaying the onset of AIDS by at least 20 years. Africa is without doubt more heavily affected by HIV/AIDS than any other region of the world. Unfortunately the spread of HIV/AIDS in Africa is quickly outpacing the number of people receiving treatment and the access to essential medicines. The implication is that to many Africans, being infected with HIV/AIDS is equivalent to a death sentence. This paper will examine the importance of compulsory licensing to facilitate access to life-serving medications for Africans and will explore the global debate on the TRIPS Agreement and public health. Specifically, it will focus on the implications, and limitations, of the Doha Declaration to compulsory licensing. The paper will further make recommendations for narrowing the divergence between the needs of HIV/AIDS patients and the protection of patent holders Intellectual Property Rights (IPRs).
Estimation of energy and moisture fluxes for dynamic vegetation using coupled SVAT and crop‐growth models

[1] A Soil Vegetation Atmosphere Transfer (SVAT) model, viz. Land Surface Process (LSP) model, is coupled with a widely used crop-growth model, DSSAT, to estimate energy and moisture fluxes at the land surface and in the vadose zone for growing vegetation. In this study, we present detailed observations of soil and crop characteristics, and various components of energy and water balance during a season-long field experiment for sweet corn. The data set is used to calibrate the LSP with Latin Hypercube Sampling and Pareto ranking. We compare the observations with model estimates of crop growth and development, land surface fluxes, soil moisture and temperature profiles from both the stand-alone LSP and coupled LSP-DSSAT models. We find that the model estimates of radiation fluxes, soil moisture, and soil temperature, by both the LSP and LSP-DSSAT are very similar, indicating that the LSP-DSSAT model can be used to simulate fluxes for dynamic vegetation without the need of in situ vegetation observations. Moreover, because coupling was achieved without structurally changing either of the models, the methodology in this study can be extended to coupling other SVAT and vegetation growth models.
Design sensitivity analysis and shape optimization of structural components with hyperelastic material

Abstract A continuum-based design sensitivity analysis (DSA) method is developed for structural components with hyperelastic (incompressible) material. A mixed variational principle (MVP) and the total Lagrangian formulation are used for nonlinear analysis. Effects of large displacements, large strains, and material nonlinearities are included in the analysis model, using appropriate kinematics and constitutive relations. The material property and shape DSA using both the direct differentiation method (DDM) and the adjoint variable method (AVM) are discussed. For shape DSA, the material derivative concept is used to compute effects of the shape variation. The boundary displacement and isoparametric mapping methods are employed to compute the design velocity field. Both hydrostatic pressure and structural stiffness are considered as constraints for design optimization, which is carried out by integrating shape design parameterization, design velocity computation, DSA, nonlinear analysis, and the optimization method. Examples such as, an engine mount and a bushing demonstrate the feasibility of the proposed optimization method for designing structural components using hyperelastic material.
Threat-sensitive predator avoidance in damselfish-trumpetfish interactions

Predatory threat can vary during a predator-prey interaction as an attack escalates or among predators at different times. A Threat-sensitivity hypothesis is presented which predicts that prey individuals will trade-off predator avoidance against other activities by altering their avoidance responses in a manner that reflects the magnitude of the predatory threat. This hypothesis was tested in the field by presenting prey (threespot damselfish, Stegastes planifrons) with models of foraging predators (Atlantic trumpetfish, Aulostomus maculatus). During a presentation, damselfish displayed progressively stronger avoidance as predator models were brought nearer; response waned rapidly once predator models passed overhead. Larger predator models and those oriented in a strike pose evoked stronger avoidance reactions than smaller and non-attacking models, intermediate responses were evoked by size and orientation combinations that were intermediate in threat, and habituation was more common to weakly-threatening presentations. Smaller damselfish showed stronger avoidance of models than did larger damselfish. Nonavoidance activities, such as feeding and territorial defense, were curtailed during presentations or were more common during weakly threatening presentations. Approaches to the models, equated with mobbing, were more common among large damselfish, again reflecting degrees of vulnerability among different size prey individuals. These initial results indicate that damselfish threatened by predators respond in a graded manner that reflects the degree of threat posed by the predator, in accordance with the Threat-sensitivity hypothesis.
In vivo phosphocreatine and ATP in piglet cerebral gray and white matter during seizures

Abstract The creatine kinase (CK) reaction is thought to be important in coupling ATP metabolism and regulating ADP concentration in tissues with high and variable ATP turnover, including cerebral gray matter (GM). There is low phosphocreatine (PCr), low CK reaction rates, and high mitochondrial CK (MiCK) isoenzyme activity in GM compared to white matter (WM). To compare the CK reaction in GM and WM when ATP metabolism is high, CK reactants and reaction rates were measured in predominantly GM and WM slices in vivo in 2 and 14-day old piglets during pentylenetetrazole (PTZ) seizures using 31 P nuclear magnetic resonance (NMR) 1-dimensional chemical shift imaging (CSI). Arterial pressure, temperature, and blood gasses were stable at both ages. Before seizures, the PCr/nucleoside triphosphate (NTP) ratio was higher in WM than GM at both ages with a developmental increase seen in WM. The CK reaction rate constant increased in both regions between 2 and 14 days. During seizures, PCr/NTP increased in GM at 14 days due to increased PCr while the ratio and PCr decreased in WM. The NTP was more stable in WM and GM at both ages. The CK reaction rate decreased in both regions more at 2 than at 14 days. Thus, brain ATP, deduced from NTP, is stable during seizures in the piglet. In GM stable ATP is associated with a unique increase in PCr concentration.
Analysis of the intervalence band in the oxidized photosynthetic bacterial reaction center

Electronic and vibronic coupling parameters of the oxidized photosynthetic bacterial reaction center (P{sup +}) of Rhodobacter sphaeroides are estimated by analyzing its nearly 2600 cm{sup -1} intervalence band which was recently measured by Breton et al. A two-node model is used which pictures P{sup +} as an unsymmetrical mixed-valence dimer. One mode (q{sub 1}) has even and the other mode (q{sub 2}) has odd interchange symmetry with respective frequencies v{sub 1} = 154 cm{sup -1} and v{sub 2} = 1630 cm{sup -1}. The vibronic coupling is strong in the former and weak in the latter and in sum is larger than the electronic coupling. The asymmetry parameter which appears in the model is estimated from the ESR data of Rautter et al. The energy difference between the minima of the two coupled potential surfaces is = 850 cm{sup -1}, whereas the Frank-Condon transition energy is = 2100 cm{sup -1}. An analysis of the potential surfaces and probability distribution in configuration space show that P{sup +} is a strongly delocalized mixed-valence system. 18 refs., 3 figs., 1 tab.
Chemopreventive Activity of Vitamin E in Breast Cancer: A Focus on γ- and δ-Tocopherol

Vitamin E consists of eight different variants: α-, β-, γ-, and δ-tocopherols (saturated phytyl tail) and α-, β-, γ-, and δ-tocotrienols (unsaturated phytyl tail). Cancer prevention studies with vitamin E have primarily utilized the variant α-tocopherol. To no avail, a majority of these studies focused on variant α-tocopherol with inconsistent results. However, γ-tocopherol, and more recently δ-tocopherol, have shown greater ability to reduce inflammation, cell proliferation, and tumor burden. Recent results have shown that γ-enriched mixed tocopherols inhibit the development of mammary hyperplasia and tumorigenesis in animal models. In this review, we discuss the possible differences between the variant forms, molecular targets, and cancer-preventive effects of tocopherols. We recommend that a γ-enriched mixture, γ- and δ-tocopherol, but not α-tocopherol, are promising agents for breast cancer prevention and warrant further investigation.
Transport of α-aminoisobutyric acid across the blood-brain barrier studied with in situ perfusion of rat brain

Abstract Transport of α-aminoisobutyric acid (AIB) from blood to brain in pentobarbital-anesthetized rats was examined using in situ perfusion. In situ perfusion with washed sheep red blood cells allowed the precise control of the composition of the perfusate that was necessary for a detailed examination of the transport of AIB. Retrograde perfusion at 4 ml/min through the left external carotid artery with oxygenated, artificial blood (hematocrit= 0.3) maintained a normal electroencephalogram during a 10 min experiment. The perfusate cerebral blood flow, at a value of 1.2 ± 0.1ml/g/min, and the perfusate cerebral plasma volume, at a value of 5.4 ± 1.9 μl/g, in the left frontal cortex were within the range of reported in vivo values. The in situ PS product for AIB (3.8 ± 0.4 μl/g/min) was higher than the value observed in vivo. AIB uptake was reduced to the in vivo value by 2 mM phenylalanine (1.3 ± 0.3 μl/g/min) and equally well by a mixture of neutral amino acids at their normal plasma concentrations but was unaffected by 2 mM methyl-AIB or removal of sodium from the perfusate. A kinetic analysis showed that the apparent K i for phenylalanine inhibition of AIB transport was 19.8 ± 4.9 μM. Thus, although AIB has affinity for the large neutral amino acid carrier in the blood-brain barrier, brain uptake by this mechanism in vivo is negligible due to competition by other amino acids in the plasma.
Racemization of Amino Acids in Bones

IT has been shown that the extent of racemization of amino acids in a fossil can be used with certain limitations to estimate the age of the specimen1–6. For this dating work it is necessary to understand the kinetics and mechanism of the reactions involved. Here we show, by kinetic studies using modern bovine bone fragments heated in sealed ampoules for various time periods at several elevated temperatures, that the order of racemization rates of amino acids in bone is aspartic acid>alanine=glutamic acid>isoleucine≅leucine. Fossil bones not contaminated with modern amino acids are shown to have the same sequence of racemization rates.
Botulinum toxin A in the overactive bladder: current status and future directions.

Authors from America present a comprehensive review of botulinum toxin A in the overactive bladder. The use of this agent in resistant cases is becoming more prevalent, and these authors have carried out an extensive literature search to establish its current status and other future directions that it might take. The other reviews concern urological cancer, two relating to prostate cancer and one to molecular targeting agents used in the treatment of metastatic RCC.
Design considerations for reliability of the Novacor LVAS wearable control system

Novacor has had clinical experience with implantable left ventricular assist systems since 1984. Following the clinical introduction and use of the console-based system, development of a compact, wearable, electronic control system was started. This is a life support device and reliability has always been a primary development concern within Novacor. This paper presents some of the considerations for reliability during the design and qualification of the wearable control system. Results of life testing of the control system and its components are presented.
Structural study of monolayers of alkyl side chain substituted polyimides

Abstract Monolayers of alkyl side chain substituted preformed polyimides (BACBP/BPDA) exhibit behaviour different from that of other `hairy-rod' polymers which were studied previously. This behaviour is thought to arise from the extreme rigidity of the backbone as well as the particular way in which the alkyl side chains extend from the biphenyl unit. These soluble polyimides can form metastable monolayers for which the pressure-area isotherms vary markedly with side chain length. This side chain length dependence suggests that the side chains can not readily project away from the water surface, but rather occupy considerable space at the interface at lower temperatures. For the polyimide with octadecyl side chains, a sharp reduction in zero pressure area occurs between 20 and 24°C, suggesting an important change in side chain mobility, while the polyimide with heptyl side chains shows no strong dependence of zero pressure area on temperature. These materials are promising for creating robust molecularly thin layers.
Development of a poroelastic dynamic mechanical analysis technique for biphasic media

Magnetic resonance elastography is a technique where mechanical properties of materials are estimated by fitting a mechanical model to an MRI-acquired displacement field. These models have been primarily limited to viscoelasticity and linear elasticity, and only recently has poroelasticity been utilized as an applied model. To validate these estimates, the same material is measured via an independent dynamic mechanical analysis device. However, these devices only apply analytic viscoelastic models. In some cases, there is a model mismatch if a viscoelastic mechanical analysis is being compared to a poroelastic model in elastography. Thus, a poroelastic dynamic mechanical analysis technique is needed to properly measure porous media and compare the results with the appropriate elastography technique. A finite element technique was implemented on a TA-Q800 Dynamic Mechanical Analysis machine similar to the algorithm used in the corresponding MR elastography method. A viscoelastic version of the finite element code was created to validate the theory and show results similar to those obtained by the analytic DMA solution. Also, differences were seen that can be attributed to inertial forces not accounted for by an analytical solution. A poroelastic algorithm was then applied, showing great promise in the ability to measure properties of porous tissues.
A new approach to array geometry for improved spatial spectrum estimation

In this letter, we address the problem of element placement in a linear aperiodic array for use in spatial spectrum estimation. By making use of a theorem by Caratheodory, it is shown that, for a given number of elements, there exists a distribution of element positions which, for uncorrelated sources, results in superior spatial spectrum estimators than are otherwise achievable. The improvement is obtained by constructing an augmented covariance matrix, made possible by the choice of element positions, with dimension greater than the number of array elements. The augmented matrix is then used in any of the known spectrum estimation methods in conjunction with a correspondingly augmented search pointing vector. Examples are given to show the superior detection capability, the larger dynamic range for spectral peak to background level, the lower sidelobes, and the relatively low bias values, when one of the known spectrum estimation techniques based on eigenstructure is used.