cssi/SciSciGPT-SciSciNet huggingface dataset:
Using state space grids to analyze teacher–student interaction over time

In this article, we explain how our inquiry worldview informs one methodological approach we have used to better understand classroom processes and change, State Space Grids (SSGs). We describe our...
Consumer ethnocentric behavior and food choices in developing countries: The case of Nigeria

Abstract With rising incomes and urbanization, diets across Sub-Saharan Africa (SSA) have diversified in source and form, encompassing more processed and packaged foods. While previous studies have identified ethnocentrism to be an influencing factor of purchase behavior, so far, no study has evaluated consumer ethnocentrism for food products in Nigeria. We conducted a study involving 2250 Nigerian consumers, using a widely validated consumer ethnocentric tendencies scale (CETSCALE). We aimed to answer the following questions: i) Are Nigerian consumers ethnocentric and how does this vary by socio-demographics? ii) Does consumer ethnocentrism affect their purchase frequency of imported food products? iii) What roles do country image and relatedly food safety concerns play in food purchasing behavior of imported food? We find that consumer ethnocentrism is indeed established in Nigeria among a large share of consumers. It is driven by key factors such as country image and food safety, and it tends to be strongly affected by socio-demographics such as income and education. We also find that ethnocentrism’s influence on purchase behavior varies across food categories. Our findings suggest that COO-labelling and a reliable formalization of product traceability with the support of the government could allow marketers to better capitalize on consumer ethnocentrism.
Open Data for Algorithms: Mapping Poverty in Belize Using Open Satellite Derived Features and Machine Learning

Mapping the spatial distribution of poverty and incomes within a country remains a challenge. Recently, several proposed methods incorporate features from satellite imagery to improve model perform...
Multispectral Coherent LADAR using Quantum Cascade Lasers for 3-D Chemical Sensing

A seven wavelength coherent LADAR comprised of distributed feedback quantum cascade lasers was developed for 3-D chemical sensing. Demonstration of 3-D chemical identification was performed on a spatially-overlapping multi-material scene.
Case Study: Participatory Mapping and Management of Conflict of Interests over Allocation of Resources Within the Aboma Forest Reserve at Kofiase, Ghana

Rapidly changing resource management contexts and competition for scarce resources among local groups are inducing joint action in the management of resources. This is the situation in Ghana where the usurpation of powers of traditional institutions by colonial administrators left community forest resources unprotected and produced attitudes of confrontation and reciprocal mistrust that continue to plague the country’s resource institutions. Local resource managers are therefore compelled to widen the range of interests they consider when they make resource policies. With the transfer of PGIS applications into the country therefore is the expectation that the initiative will create opportunities for public participation in the management of emerging resource conflicts. This chapter describes the application of a decision support algorithm for managing a resource allocation problem involving competing interests. A case involving multiple claims to resources in the Aboma Forest Reserve located at Kofiase in Southern Ghana is used to illustrate participatory GIS applications. The chapter begins with a discussion of the study area and background to the problem. This is followed by a review of GIS-multicriteria decision-making techniques. After this, the GIS-aided participatory mapping approach is applied to the forest resource allocation problem at Kofiase, Ghana.
Update on Clonal Hematopoiesis

Abstract Clonal hematopoiesis (CH), defined as the clonal expansion of mutated hematopoietic stem cells (HSCs), is a common aging process. CH is known to be strongly associated with the development of hematologic malignancies, most commonly myeloid neoplasms (MN) including acute myeloid neoplasm and myelodysplastic syndrome (MDS).1–6 Recent work has elucidated how the development and cellular fitness of CH is shaped by human aging, environmental exposures, and the germline (inherited) composition of an individual. This in turn provides valuable insights into the pathogenesis of MNs including MDS.
A Biophysical Model of Nonquantal Transmission at the Vestibular Hair Cell-Calyx Synapse: KLV currents Modulate Fast Electrical and Slow K+ potentials in the Synaptic Cleft

Vestibular hair cells transmit information about head position and motion across synapses to primary afferent neurons. At some of these synapses, the afferent neuron envelopes the hair cell, forming an enlarged synaptic terminal referred to as a calyx. The vestibular hair cell-calyx synapse supports nonquantal transmission (NQT), a neurotransmitter-independent mechanism that is exceptionally fast. The underlying biophysical mechanisms that give rise to NQT are not fully understood. Here we present a computational model of NQT that integrates morphological and electrophysiological data. The model predicts that NQT involves two processes: changes in cleft K+ concentration, as previously recognized, and very fast changes in cleft electrical potential. A significant finding is that changes in cleft electrical potential are faster than changes in [K+] or quantal transmission. The electrical potential mechanism thus provides a basis for the exceptional speed of neurotransmission between type I hair cells and primary neurons and explains experimental observations of fast postsynaptic currents. The [K+] mechanism increases the gain of NQT. Both processes are mediated by current flow through low-voltage-activated K+ (KLV) channels located in both pre-synaptic (hair cell) and post-synaptic (calyx inner face) membranes. The model further demonstrates that the calyx morphology is necessary for NQT; as calyx height is increased, NQT increases in size, speed and efficacy at depolarizing the afferent neuron. We propose that the calyx evolved to enhance NQT and speed up signals that drive vestibular reflexes essential for stabilizing the eyes and neck and maintaining balance during rapid and complex head motions.
Geography Achievement and Opportunity to Learn: A Focus on Computer and Educational Technology

Computers and geospatial technologies such as Geographic Information Systems, Google Earth, and the Global Positioning System (GPS) are increasingly common tools for geography instruction in school...
Modified kinetics of enzymes interacting with nanoparticles

Enzymes are important players in multiple applications, be it bioremediation, biosynthesis, or as reporters. The business of catalysis and inhibition of enzymes is a multibillion dollar industry and understanding the kinetics of commercial enzymes can have a large impact on how these systems are optimized. Recent advances in nanotechnology have opened up the field of nanoparticle (NP) and enzyme conjugates and two principal architectures for NP conjugate systems have been developed. In the first example the enzyme is bound to the NP in a persistent manner, here we find that key factors such as directed enzyme conjugation allow for enhanced kinetics. Through controlled comparative experiments we begin to tease out specific mechanisms that may account for the enhancement. The second system is based on dynamic interactions of the enzymes with the NP. The enzyme substrate is bound to the NP and the enzyme is free in solution. Here again we find that there are many variables , such as substrate positioning and NP selection, that modify the kinetics.
Data Mining for Fuzzy Decision Tree Structure with a Genetic Program

A resource manager (RM), a fuzzy logic based expert system, has been developed. The RM automatically allocates resources in real-time over many dissimilar agents. A new data mining algorithm that uses a genetic program, an algorithm that evolves other computer programs, as a data mining function has been developed to evolve fuzzy decision trees for the resource manager. It not only determines the fuzzy decision tree structure it also creates fuzzy rules while mining scenario databases. The genetic program's structure is discussed as well as the terminal set, function set, the operations of cross-over and mutation, and the construction of the database used for data mining. Finally, an example of a fuzzy decision tree generated by this algorithm is discussed.
A reconfigurable multiprocessor IC for prototyping of real-time data paths

In real-time digital-signal processing systems, data often enter or leave the computationally intensive parts at small integer multiples of the clocking interval. In these cases, traditional microprocessor-based architectures are inadequate to meet the throughput requirements, and so clusters of dedicated data paths, hard-wired to closely match the algorithmic data flow, are often used. These architectures typically contain multiple concurrently operating data-path pipelines. The circuit reported targets the rapid implementation and prototyping of such architectures using reconfigurable multiprocessors. This circuit contains eight execution units (EXUs) connected via a dynamically controlled crossbar switch. It can operate at 25 MHz (200 MIPs) with a data I/O bandwidth of 400 MB/s and a typical power consumption of 0.45 W. It contains 140106 transistors on a 8.9*9.5 mm/sup 2/ die, in 1.2- mu m CMOS technology. >
Is There an Intragroup Medium in the Local Group

Direct constraints on the presence of a diffuse intragroup medium within the Local Group are surprisingly hard to come by. It is also not clear whether the Local Group is sufficiently dynamically evolved to possess such a medium. I will discuss the existing constraints on a local diffuse IGM, both direct and indirect, and answer the question posed in my title with a definitive “Maybe, maybe not.”
On Shostak's Decision Procedure for Combinations of Theories

Decision procedures are increasingly being employed for deciding or simplifying propositional combinations of ground equalities involving uninterpreted function symbols, linear arithmetic, arrays, and other theories. Two approaches for constructing decision procedures for combinations of ground theories were pioneered in the late seventies. In the approach of Nelson and Oppen, decision procedures for two disjoint theories are combined by introducing variables to name subterms and iteratively propagating any deduced equalities between variables from one theory to another. Shostak employs a different approach that works far more efficiently in practice. He uses an optimized implementation of the congruence closure procedure for ground equality over uninterpreted function symbols to combine theories that are canonizable and algebraically solvable. Many useful theories have these properties. Shostak's algorithm is subtle and complex and his description of this procedure is lacking in rigor. We present, for the first time, a careful development and clarification of Shostak's procedure that corrects several mistakes in Shostak's original presentation. Our analysis serves as a useful basis for the implementation, extension, and further optimization of Shostak's decision procedure.
Destination Based Indirect Taxation: The Case of Bosnia and Herzegovina

Development of a strategy to foster strong economic growth was seen by the international community as a key aspect to nation building and sustaining the end of the armed conflict in Bosnia and Herzegovina. Tax policy was a key aspect of the strategy, but the very decentralized institutional arrangements and limited cooperation between the governments complicated the design. This paper reviews and assesses the indirect tax structure that has been the focus of the first five years. Among the findings are the importance associated with creating destination-based revenue attribution, the strong tendencies for tax competition, the unwillingness to accept formula-based revenue distribution, and the high administrative and compliance costs that result from structuring a system to achieve all of the necessary goals in a decentralized government context.
Information sharing for distributed planning

Large-scale collaborative planning is critical in many domains such as sensor networks and disaster rescue. In large, heterogeneous multiagent teams, agents must work together to create plans that maximize the effectiveness of the team as a whole; coordinating actions to increase efficiency while also avoiding potentially dangerous interactions between teammates. Recognizing the utility of information to agents in teams and delivering it efficiently across a team has also been the focus of much research, with proposed approaches ranging from classic flooding, gossiping, to channel filtering. We combine these two fields of research to study the problem of information sharing mechanisms to distribute planning in both certain and uncertain environments.
Commentary re: Q-T Le et al, identification of osteopontin as a prognostic marker for head and neck squamous cell carcinomas. clin cancer res, 9: 31-32, 2003.

The protein now known as OPN[2][1] was first identified and characterized in two contexts: ( a ) in bone as a phosphorylated sialoglycoprotein [(1)][2] ; and ( b ) in cultures of transformed cells as transformation-related phosphoprotein [(2)][3] . The rat cDNA encoding the bone protein was cloned
Effect of Renal Ischemia in Laparoscopic Acute Versus Chronic Solitary Kidney Model

Abstract Objectives The effects of renal warm ischemia (WI) in an acute versus a chronic single kidney model have not been investigated. Previously, we reported full recovery of renal function after 90 minutes of WI in a single-kidney porcine model. Here, we sought to assess the effects of WI on renal function in an acute versus chronic solitary kidney in the porcine model. Methods A total of 32 pigs weighing 60 to 80 lb were randomized into four groups. Group 1 (acute model) underwent nephrectomy followed by 90-minute immediate WI clamping of the contralateral renal hilum. Group 2 (control for group 1) underwent nephrectomy followed by contralateral sham renal pedicle surgery. Group 3 (chronic model) underwent nephrectomy followed 12 days later by 90-minute WI clamping of the contralateral renal hilum. Group 4 (control for group 3) underwent nephrectomy followed 12 days later by contralateral sham renal pedicle surgery. Serum creatinine and the glomerular filtration rate were assessed preoperatively and on postoperative days 1, 3, 8, and 15. All procedures were performed laparoscopically. Results The acute model showed a significantly greater increase in serum creatinine and lower glomerular filtration rate nadir compared with the chronic model on postoperative days 1, 3, and 8. By postoperative day 15, the serum creatinine and glomerular filtration rate were comparable between the acute and chronic groups after WI. Conclusions Renal dysfunction in the acute model was significantly more profound during the initial 8 days after WI compared with that in the chronic model. These results validate our acute single kidney porcine model as a practical and cost-effective model when performing renal ischemia research.
Studies on “early” enzymes in HeLa cells infected with vaccinia virus

Abstract DNA polymerase activity in the cytoplasm begins to increase within 1 1 2 hours after infection of HeLa cells with vaccinia virus (strain WR). The properties of the enzyme in normal and infected cell cytoplasmic extracts have been studied. The enzymes differ with respect to the saturating concentration of DNA primer and the shape of the pH-activity curve: enzyme from infected cells is saturated by 25 μg primer per milliliter whereas the enzyme from normal cells is only saturated by 100 μg/ml; and although the optimum pH is between 7 and 8 for both enzymes, the enzyme from infected cells is relatively more active at pH 9 than that derived from normal cells. The activity of DNase acting on single-stranded DNA also increases on infection of HeLa cells with vaccinia WR, as does the activity of thymidine kinase. The synthesis of all three enzymes is induced at the same time (about 1 1 2 hours after infection), is arrested at any time during the rise period by the addition of puromycin, and is switched off at about 4 hours after infection. The switch-off mechanism for all three enzymes fails to operate when synthesis of progeny viral DNA is inhibited. However, there is one significant difference: whereas the synthesis of thymidine kinase is induced by virus inactivated with UV-irradiation, synthesis of DNA polymerase and DNase (single-stranded DNA) is not. The virus-induced synthesis of both DNA polymerase and thymidine kinase continues for at least 5 hours after the addition of actinomycin D at a not significantly reduced rate. This signifies that the messenger RNAs coding for these “early” enzymes are remarkably long lived.
Making do: The effects of a mass transit strike on travel behavior

A brief transit strike in early December 1976 disrupted bus services to the city of Pittsburgh and surrounding Allegheny County. That strike provided an opportunity for testing a variety of approaches to increase ride-sharing and to reduce traffic congestion, and for examining the effect of the strike on traffic congestion and on individual travel behavior. Even though over 60% of the commuters to the CBD use transit, the effects of the strike were relatively mild. There was some increase in traffic flow into the CBD and some spreading of the peak period. The largest proportion of the transit commuters who made trips to the CBD during the strike were dropped off by a non-commuter, increasing highway traffic. The most severe impact was felt by those transit commuters who had no cars in the household; 25% of these commuters (only 3% of the total CBD commuters) stayed home from work on the first day of the strike. Most attempts to mitigate the impact of the strike had little effect, largely because most commuters were able to manage adequately during the short strike. The anticipated parking problem, on which much of the contingency planning was focused, did not emerge, largely because of the use of carpooling and “drop-off” mode by many of the transit users.
Superconducting quantum circuits at the surface code threshold for fault tolerance

A quantum computer can solve hard problems, such as prime factoring, database searching and quantum simulation, at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection by distributing a logical state among many physical quantum bits (qubits) by means of quantum entanglement. Superconductivity is a useful phenomenon in this regard, because it allows the construction of large quantum circuits and is compatible with microfabrication. For superconducting qubits, the surface code approach to quantum computing is a natural choice for error correction, because it uses only nearest-neighbour coupling and rapidly cycled entangling gates. The gate fidelity requirements are modest: the per-step fidelity threshold is only about 99 per cent. Here we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92 per cent and a two-qubit gate fidelity of up to 99.4 per cent. This places Josephson quantum computing at the fault-tolerance threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.
Diazepam binding inhibitor gene expression: location in brain and peripheral tissues of rat

Diazepam binding inhibitor (DBI), an endogenous 10-kDa polypeptide was isolated from rat and human brain by monitoring displacement of radioactive diazepam bound to specific recognition sites in brain synaptic and mitochondrial membranes. The cellular location of DBI mRNA was studied in rat brain and selected peripheral tissues by in situ hybridization histochemistry with a 35S-labeled single-stranded complementary RNA probe. DBI mRNA was heterogeneously distributed in rat brain, with particularly high levels in the area postrema, the cerebellar cortex, and ependyma of the third ventricle. Intermediate levels were found in the olfactory bulb, pontine nuclei, inferior colliculi, arcuate nucleus, and pineal gland. Relatively low but significant levels of silver grains were observed overlying many mesencephalic and telencephalic areas that have previously been shown to contain numerous DBI-immunoreactive neurons and a high density of central benzodiazepine receptors. In situ hybridizations also revealed high levels of DBI mRNA in the posterior lobe of the pituitary gland, liver, and germinal center of the white pulp of spleen, all tissues that are rich in peripheral benzodiazepine binding sites. The tissue-specific pattern of DBI gene expression described here could be exploited to further understand the physiological function of DBI in the brain and periphery.
Single vibronic level photochemistry of formaldehyde (H2CO, 1A2): Radiative and non-radiative transitions

Abstract Fluorescence decay times and fluorescence emission quantum yields from various single vibronic levels of the first excited singlet state of H2CO (A, 1A2) have been measured. Radiative and non-radiative lifetimes of the single vibronic levels have been determined. Surprisingly, the stronger promoting vibrational mode for the radiative transition is the asymmetric stretch mode (ν′5) rather than the out-of-plane bending mode (ν′4). The latter mode, however, is a promoting mode for the non-radiative transition. As much as a factor of ≈40 variation in the τr values is observed for the variety of vibrational states studied.
Framing the War on Terror in Canadian Newspapers: Cascading Activation, Canadian Leaders, and Newspapers

This essay examines the differences in coverage of the Afghanistan and the Second Persian Gulf War within the Toronto Star, Winnipeg Free Press, and Vancouver Sun. I examine Robert M. Entman's model by exploring the role foreign news outlets play in the dissemination of American foreign policy frames across the globe. In cases where the frame offered by the White House is accepted by the foreign leaders, journalists extend and enhance it, but in instances where there is disagreement with the White House frame reporters enhance the elite criticism offered toward the White House. This essay contributes to a better understanding of Entman's cascading activation model for news framing as it explores how White House frames cascade through foreign leaders and foreign media.
A time-dependent functional theory for the electron-ion system

Abstract It is shown that a time-dependent single particle potential ν e ( r t) and a time-dependent force on the ion F (lKt) with a given fixed initial state of the combined electron-ion system, leading respectively to a given ν-representable electronic density n( r t) and ionic displacement R (lKt) , are determined so that a map (ν e , F )→(n, R ) is invertible. This formulation allows us to ad dress the effective self-consistent ion dynamics of the electron-ion system in contrast to existing treatments such as those based on the Car-Parrinello approach by replacing the fictitous Lagrangian introduced there by a precise action principle. Based on this, some schemes are derived to calculate the density, the displacement, etc. using the stationary action principle and some convenient choices of a suitably parametrised state vector.
Development of an Instrument To Measure Classroom Community

Abstract The purpose of this study was to develop and field-test the Classroom Community Scale and to determine its validity and reliability for use with university students taking courses at a distance via the Internet. The 20-item Classroom Community Scale measures sense of community in a learning environment. Data were collected from 375 students enrolled in 28 different courses, offered for graduate credit via the Blackboard e-learning system by a private university. It was concluded that the Classroom Community Scale is a valid and reliable measure of classroom community and that this instrument yields two interpretable factors, connectedness and learning.
Assimilation and Heritage Identity: Lessons from the Coptic Diaspora

Many first generation immigrants share a concern for retaining their heritage culture, though they still aspire to successfully assimilate into the country of residence society. Assimilation theories suggest facilitating factors for positive assimilation but differ in terms of whether the loss of heritage culture is inevitable. The Coptic diaspora illustrates that upward mobility can be achieved without loss of heritage identity. Religious structures can play an important role not only in sustaining heritage identity but also facilitating positive assimilation. A review of the Coptic Orthodox Church’s ministry in diaspora, along with findings of a Coptic diaspora survey may offer lessons for other immigrant groups. The study affirms some theoretical findings and raises questions for future research.
Computation of Unsteady Viscous Flow Using a Pressure-Based Algorithm

The objective of this research is the development of an efficient and accurate numerical analysis for the prediction of unstready turbulent flows using a Navier-Stokes solver. The technique developed is to be used for incompressible flow and is an extension of the pressure-based method. The finite volume approach and a nonstagger grid formulation are used. A predictor-corrector type algorithm is applied to the governing equations to ensure time accuracy. The convergence is improved using a multigrid scheme
Liver transplantation for hepatitis B in the United States.

Abstract Aim To evaluate the impact of hepatitis B virus (HBV) on US health care system, we reviewed the Organ Procurement and Transplantation (OPTN, formerly UNOS) HBV database. Method We reviewed records of liver transplantations (LTx) performed in the United States listed for the diagnoses of HBV between 1993 and mid-October 2004. Both acute as well as chronic cases were included. Coinfection with hepatitis C virus was excluded from study. The specific states selected for review were chosen from those areas that are receiving large numbers of new immigrants from high HBV endemic areas (ie, Texas, Pennsylvania, California, New York, and Florida). One-, 3-, and 5-year patient survival rates for both cadaveric and living related donors were analyzed. Survival rates were obtained from OPTN database as Kaplan-Meyer survival test. Results Between 1993 and mid-October 2004, 53,312 LTx had been performed nationwide. Of these, 2314 (4.34%) were performed for the diagnosis of HBV; 1816 cases (78%) were due to chronic HBV infection (45 of them were living donor LTx) and 498 cases (22%) were due to HBV-induced acute liver failure (seven of them were living donor LTx). Three- and 5-year survival rates of chronic HBV-related LTx patients were better than acute HBV-related and overall LTx patients. Conclusion HBV is generally considered to have a minor health significance by many community gastroenterologists. With growing immigration from overseas, it may eventually have a higher impact on LTx. Therefore, it is crucial to further educate gastroenterologists and primary care physicians caring for this specific group of patients.
An Analysis of Civil Suits Filed Against Private and Public Prisons: A Comparison of Title 42: Section 1983 Litigation:

This study examines civil litigation filed against private and public prisons. Suits alleging violation of Title 42: Section 1983 were considered. Findings reveal that judicial statements made in response to private sector litigation carried greater amounts of admonishment than did judicial statements made in response to litigation filed against the public sector. Furthermore, it is evident that a portion of the federal judiciary views privatization as potentially having negative effects on inmates and staff.
Symbolic mediation and commoditization: a critical examination of alcohol use among the Haya of Bukoba, Tanzania.

Low‐alcohol‐content fermented beverages are thoroughly enmeshed in the social, economic, commensal, and cosmological spheres of life among most peoples of sub‐Saharan Africa. This paper describes and analyzes the role of alcoholic beverages as symbolic mediators and commodities among the Haya of northwest Tanzania. Data gathered during field research in 1985–86 are employed to describe the ways in which the Haya portray excessive drinking and the indigenous strategies they use to address frequent drunkenness when it is perceived as a health problem. A central feature of the paper contrasts the role of a cultural schema of four levels of intoxication in processes of symbolic mediation and commoditization, thereby contributing to critical medical anthropological analysis.
Physiology and biophysics in electrocardiography

In this issue of the Journal ofElectrocardiology, Castini et al. report electrocardiographic (ECG) findings supporting the validity of the Brody effect (1). This effect, reported in 1956 by Dr. Daniel Brody, describes the theoretical relationship between the conductivity of the blood mass contained within the heart and the potentials recorded outside the heart (2). The net result, as summarized by Brody, was that "the relatively large conductivity of the intracavitary blood mass tends to short-circuit the tangential components, but augments the radial components of myocardial doublets" (2). Because transmural ventricular activation is predominantly radial, increasing the size or conductivity of the left ventricular chamber would be predicted to enlarge body surface R waves. Castini et al. reported lower R wave amplitudes in patients after reducing ventricu]ar volume by venous compression (1), a finding expected from the Brody effect. To understand these data fully, it is important to distinguish between two fundamental factors that determine the amplitude and pattern of ECG potentials on the body's surface, namely, physiologic and biophysical variables. It is the interaction of these two sets of factors that, in the final analysis, determines body surface ECG potentials. Physiologic factors affecting the ECG are well known. The myocardial cell is the fundamental biologic cardiac generator, which generates cardiac electrical potentials as a result of multiple, timedependent ionic currents that traverse the cell membrane. The electrical activity of these cells is synchronized by the interaction of the specialized
Evaluation of highly reactive mono-methacrylates as reactive diluents for BisGMA-based dental composites.

Abstract Objectives This study evaluates the performance of highly reactive novel monomethacrylates characterized by various secondary moieties as reactive diluent alternatives to TEGDMA in BisGMA filled dental resins. We hypothesize that these monomers improve material properties and kinetics over TEGDMA because of their unique polymerization behavior. Methods The cure rates and final double bond conversion of the resins were measured using real-time FTIR spectroscopy. The glass transition temperature and storage modulus of the formed polymers were measured using dynamic mechanical analysis. Flexural modulus and flexural strength values were obtained using a three-point bending flexural test. Results Polymerization kinetics and polymer mechanical properties were evaluated for the novel resin composites. It was observed that upon the use of novel monomethacrylates as reactive diluents, polymerization kinetics increased by up to 3-fold accompanied by increases in the extent of cure from 5% to 13% as compared to the BisGMA/TEGDMA control. Polymer composites formed from resins of BisGMA/novel monomethacrylates exhibited comparable T g values to the control, along with 27–37% reductions in the glass transition half widths indicating the formation of more homogeneous polymeric networks. The BisGMA/monomethacrylate formulations exhibited equivalent flexural modulus and flexural strength values relative to BisGMA/TEGDMA. Significance Formulations containing novel monovinyl methacrylates exhibit dramatically increased curing rates while also exhibiting superior or at least comparable composite polymer mechanical properties. Thus, these types of materials are attractive for use as reactive diluent alternatives to TEGDMA in dental formulations.
The occurrence of rutin in Sambucus canadensis.

Using an accepted method for its isolation, the occurrence of rutin has been established in elder during a seasonal growing period. The results show that rutin occurs in amounts up to 0.52 per cent and that there is variation in the amount in plants growing under different conditions. Spectrophotometric assay data are presented.
Effects of “smoking” doses of nicotine on RBC velocity in mesenteric capillaries

Abstract The purpose of these studies was to investigate the effects of nicotine in doses equivalent to tobacco smoking on capillary blood flow in the mesentery. Anesthetized cats were administered nicotine intravenously in a sequential dose schedule of 8, 16, and 32 μg/kg while RBC velocity in single mesenteric capillaries and systemic arterial blood pressure were recorded. Both blood pressure and capillary RBC velocity increased in proportion to nicotine dose. Although the increases in average RBC velocity were proportionately greater than corresponding changes in blood pressure, the ratio of pressure to velocity (an index of precapillary resistance) did not significantly change.
Voltage-dependent and Src-mediated regulation of NMDA receptor single channel outward currents in cortical neurons.

A voltage-dependent but Ca2+-independent regulation of N-methyl-D-aspartate (NMDA) receptor outward activity was studied at the single channel level using outside-out patches of cultured mouse cortical neurons. Unlike the inward activity associated with Ca2+ and Na+ influx, the NMDA receptor outward K+ conductance was unaffected by changes in Ca2+ concentration. Following a depolarizing pre-pulse, the single channel open probability (NP o), amplitude, and open duration of the NMDA inward current decreased, whereas the same pre-depolarization increased those parameters of the NMDA outward current (pre-pulse facilitation). The outward NP o was increased by the pre-pulse facilitation, disregarding Ca2+ changes. The voltage–current relationships of the inward and outward currents were shifted by the pre-depolarization toward opposite directions. The Src family kinase inhibitor, PP1, and the Src kinase antibody, but not the anti-Fyn antibody, blocked the pre-pulse facilitation of the NMDA outward activity. On the other hand, a hyperpolarizing pre-pulse showed no effect on NMDA inward currents but inhibited outward currents (pre-pulse depression). Application of Src kinase, but not Fyn kinase, prevented the pre-pulse depression. We additionally showed that a depolarization pre-pulse potentiated miniature excitatory synaptic currents (mEPSCs). The effect was blocked by application of the NMDA receptor antagonist AP-5 during depolarization. These data suggest a voltage-sensitive regulation of NMDA receptor channels mediated by Src kinase. The selective changes in the NMDA receptor-mediated K+ efflux may represent a physiological and pathophysiological plasticity at the receptor level in response to dynamic changes in the membrane potential of central neurons.
Splitting-Based Statistical X-Ray CT Image Reconstruction with Blind Gain Correction

Variational methods are useful for solving ill-posed inverse imaging problems by minimizing a cost function with a data fidelity term and a regularization term. For statistical X-ray computed tomography (CT) image reconstruction, penalized weighted least-squares (PWLS) criteria with edge-preserving regularization can improve quality of the reconstructed image compared to traditional filtered back-projection (FBP) reconstruction. Nevertheless, the huge dynamic range of the statistical weights used in PWLS image reconstruction leads to a highly shift-variant local impulse response, making effective preconditioning difficult. To overcome this problem, iterative algorithms based on variable splitting were proposed recently. However, existing splitting-based iterative algorithms do not consider the (unknown) gain fluctuations that can occur between views. This paper proposes a new variational formulation for splitting-based iterative algorithms where the unknown gain parameter vector and the image are estimated jointly with just simple changes to the original algorithms. Simulations show that the proposed algorithm greatly reduces the shading artifacts caused by gain fluctuations yet with almost unchanged computational complexity per iteration.
Cost of nosocomial infections in the pediatric intensive care unit

Nosocomial infections are associated with increases in both duration of hospital stay and associated costs. These increases cause a significant problem in the pediatric intensive care unit, where the acuity of patients and cost of delivery of care are much higher than those of other areas in the hospital. Only a few studies provide detailed information of costs attributable to nosocomial infection in the pediatric intensive care unit. The purpose of this article is twofold: to provide a summary of some of the studies that have estimated costs associated with nosocomial infections and to provide an overview of the methodological issues that surround measuring charges and costs in any cost analysis, with particular reference to nosocomial infections in the pediatric intensive care unit.
Declining volume of gastrointestinal fluoroscopies: A survey of 18 hospitals

A survey of the volume of gastrointestinal fluoroscopies at 18 hospitals suggests a decline in the number of these examinations performed over the past 5 years. Data were acquired on 4 types of examinations: upper gastrointestinal series, small bowel studies, barium enemas (all types), and oral cholecystograms. Modest decreases of 8.4%, 10.3%, and 2.0% were noted in the numbers of upper gastrointestinal examinations, small bowel examinations, and barium enemas, respectively. A considerable deline of 45.9% was found in performance of oral cholecystograms. An overall decline of 14.4% was noted for all 4 examinations.
Are There Risk Factors for Hepatitis B Infection in Inner-City Adolescents That Justify Prevaccination Screening?

Abstract Purpose: This study was undertaken to determine if homelessness could serve as a marker for previous hepatitis B infection (HBI), and thus justify prevaccination screening. Methods: One hundred sexually active 13–21-year-olds (mean = 17 years), 74% female, attending an inner-city hospital-based adolescent clinic (HOSP), and 48 sexually active 13–21-year-olds (mean = 19 years), 40% female, attending a clinic based at an urban drop-in center (UDC) for street youth were consecutively enrolled, screened for HBI serum markers and administered a structured interview about sexual practices, sexual abuse, prior sexually transmitted diseases (STDs), and injection drug use. Results: For the HOSP group, 7% were homeless and 4% were HBI positive. In the UDC group, 96% were homeless and 23% were HBI positive. Homelessness was significantly associated with HBI ( p p p ≤ 0.002), anal-receptive sex ( p ≤ 0.01), genital Chlamydia ( p ≤ 0.03), prostitution ( p ≤ 0.03), and sexual abuse ( p ≤ 0.002). For both populations, gender, sexual orientation, intravenous drug use, and genital sex were not related to HBI. Conclusion: These data indicate that homelessness and associated high-risk sexual practices may be indications for prevaccination screening for HBI in adolescents.
Anaesthesia for the traumatized patient

As in all phases of anaesthesia, perhaps the most important aspect of administering anaesthetics is to understand the natural history of the disease of the patient. It is only with the understanding of the underlying physiology and medical aspects of the patient’s disease that we can monitor the appropriate functions and safely administer drugs and medical care to the victim. This applies as much to the traumatized patient as to the obstetric patient or the patient undergoing cardiac surgery. Since in this short dissertation one cannot begin to fully describe these complex patients, we have attempted to deal with specific areas of care and to suggest approaches to dealing with some of the problems of the trauma patient.
RE: Cerebral autoregulation in different hypertensive disorders of pregnancy

TO THE EDITORS: Because hypertension is one of the major complications linked to maternal death, there is a clear need for continued investigation. van Veen et al 1 must be commended for their appropriate statistical analysis of the data on the subject. The transformations of the cerebral blood flow velocity are consistent with reliable standard methods. 2 It was also relevant to measure the bilateral cerebral blood flow velocity to control for variation between the left and
Facilitating Compound Progression of Antiretroviral Agents via Modeling and Simulation

Pharmacotherapy in human immunodeficiency virus (HIV)-infected patients and the development of safe and effective antiretroviral dosing regimens has been hindered by numerous issues, including the rapid development of viral resistance to drug therapy, the narrow therapeutic window of the drug compounds, and lack of fundamental knowledge concerning the sources of variation in exposure and response to antiretroviral agents. Sources of variation may include factors such as interpatient differences in genetic expression, immunological response, pathogenesis, epidemiologic and socioeconomic factors, and demographics. Modeling and simulation (M&S) techniques have become valuable tools to identify and quantify variability in exposure and response to antiretroviral agents throughout the drug development process. Before actual entry into human safety and pharmacokinetic (PK) trials, in vitro screening and in vivo pharmacology studies conducted to assess compound potency and compatibility with agents included in acceptable antiretroviral therapy (ART) regimens can be characterized via quantitative relationships. In addition, physiochemical data is initially used to screen drug candidates based on favorable PK and biopharmaceutic properties. Compound progression can likewise be supported with M&S exercises to ensure the traceability of key assumptions and decisions. The underlying techniques utilize nonlinear mixed effect modeling, Monte Carlo simulation, Neural networks, several regression-based approaches, and less computationally intensive techniques. The application of such an approach promises to be an essential component in the development of new agents to treat HIV-1 and is being implemented in the context of evaluating Nk1r antagonists as potential candidates to treat NeuroAIDS.
Assessment of grid interface treatments for multi-block incompressible viscous flow computation

Abstract In the multi-block computation of the Navier-Stokes equations, the interface treatment is a key issue. In the present work, we investigate this issue in the context of a pressure-based method using a non-orthogonal grid. For the momentum equations, a straightforward bilinear interpolation seems satisfactory as the interface treatment; on the other hand, because the pressure field depends on the satisfaction of the mass continuity equation, a conservative interface treatment has been found necessary for the pressure-correction equation. Two alternative interface treatments for the pressure-correction equation, one employing the Neumann boundary condition in both grid blocks, based on explicit local, cell-by-cell mass flux conservation, and the other utilizing Neumann-Dirichlet boundary conditions, allowing the interface condition in one block to be derived by interpolating the pressure field from the adjacent block, are assessed in the present work. To evaluate these interface schemes, the laminar flow inside a lid-driven cavity flow, and the turbulent flow around cascades of multiple airfoils have been investigated. For the case tested, both interface treatments give comparable accuracy. The finding that more than one type of interface treatment can work well allows one to devise a flexible multi-block strategy for complex flow computations.
Start-up flow of an upper convected maxwell fluid over a rotating disk

Abstract Start-up flow of an Upper Convected Maxwell (UCM) fluid over a disk set in rotation is studied by using analytical and numerical methods. Both instantaneous acceleration and linear ramping are considered. A power series expansion is used to calculate velocity and stress analytically at short times and for moderate and large Deborah numbers ( De ). Then momentum transfer occurs in the form of a sharp propagating wave front. For small De values, a solution using singular perturbations is developed and the wave front is totally dispersed from the beginning of rotation. The numerical calculations are carried out using either standard Finite Differences (FD) or the Split Coefficient Matrix (SCM) method. The latter uses information propagating along the characteristics direction for proper treatment of the spatial derivatives. SCM is found to be more stable and efficient than FD. De values as large as 100 have been used without breakdown of the numerical scheme.
Databases in the assessment of the effects of drugs during pregnancy

There is limited information on the effects of marketed drugs in pregnant women, largely because premarketing studies are not conducted in this population unless the agent is intended for specific use during pregnancy. Current information on the use of available medications during pregnancy includes 3 types of data: (1) case reports, (2) case-control studies, and (3) cohort studies. Assessments of pregnancy risk related to medication use most commonly involve case reports, and each year the Food and Drug Administration catalogs approximately 1000 suspected adverse drug experiences during pregnancy. The Food and Drug Administration, working with Michigan Medicaid, has developed a database of several hundred thousand pregnancy outcomes. Results of this study for asthma medications used between 1980 and 1992 are presented. However, interpretation of the results is complicated, and substantially more data are required, particularly as new medications become available.
Relative prices and electronic substitution: Changes in household-level demand for postal delivery services from 1986 to 2004

This paper quantifies the extent to which the shift in the aggregate household-level demand for postal delivery services can be attributed to the appearance of alternative modes of communication versus the concomitant rise in postal prices. We find that both recent postal price increases and the penetration of personal computer technology among US households led to similar reductions in postal expenditure. We further find that a 5% postal price increase, such as the one introduced in January 2006 reduces revenue collected from US households by $215 million and imposes an aggregate welfare loss on US households of $333 million.
An explanation of the density maximum in water.

An explanation of the anomalous density maximum in water near 4 \ifmmode^\circ\else\textdegree\fi{}C can be given in terms of a competition between the presence of open second-neighbor oxygen-oxygen structure at 4.5 \AA{} and a dense second-neighbor structure obtained from the bending of hydrogen bonds. Since no computational model of water has provided an explanation of this anomaly, altering the water-water potential to create more realistic interactions in the second-neighbor shell is proposed. Support for this idea is provided here by considering the exactly soluble Takahashi fluid model.