cssi/SciSciGPT-SciSciNet huggingface dataset:
Assistive Technology Design as a Computer Science Learning Experience

As awareness surrounding the importance of developing accessible applications has grown, work to integrate inclusive design into computer science (CS) curriculum has gained traction. However, there remain obstacles to integrating accessibility into introductory CS coursework. In this paper, we discuss current challenges to building assistive technology and the findings of a formative study exploring the role of accessibility in an undergraduate CS curriculum. We respond to the observed obstacles by presenting V11, a cross-platform programming interface to empower novice CS students to build assistive technology. To evaluate the effectiveness of V11 as a CS and accessibility learning tool, we conducted design workshops with ten undergraduate CS students, who brainstormed solutions to a real accessibility problem and then used V11 to prototype their solution. Post-workshop evaluations showed a 28% average increase in student interest in building accessible technology, and V11 was rated easier to use than other accessibility programming tools. Student reflections indicate that V11 can be an accessibility learning tool, while also teaching fundamental Computer Science concepts.
Computational modelling of adsorption and diffusion properties of CO2 and CH4 in ZIF-8 for gas separation applications: a density functional theory approach

Understanding of zeolitic imidazolate framework-8 (ZIF-8) interaction with different gas molecules is crucial when ZIF-8 is used in gas separation. Computational studies based on density functional theory (DFT) can be used to investigate gas interactions and diffusion mechanisms that can be directly correlated with experimental observations. Here we present our studies based on DFT calculations on CO2 and CH4 gas adsorption and diffusion in the bulk of ZIF-8. We evaluate the structural and electronic properties of bulk ZIF-8, and determine the most stable adsorption sites and the corresponding diffusion barriers for CO2 and CH4 molecules. Our calculations incorporate long-range dispersion interactions to describe the weak interactions between adsorbate molecules and the framework. We analyze the adsorption and diffusion properties in relation with the material's volume expansion. We find that the CO2 and CH4 adsorption energies at the most stable adsorption sites are 5.01 and 4.47 kcal mol−1, respectively. The diffusivity of CO2 is found to be about two times that of CH4. Our calculated diffusion coefficients were found to have the same order of magnitude with the experimental results. Furthermore, our calculations indicate that CO2 and CH4 diffusivities in fixed ZIF-8 (all ZIF-8 framework atoms are fixed) are 5–9 times lower than the corresponding diffusion values in flexible ZIF-8 (all the framework atoms are allowed to move).
Vitamin D deficiency after allogeneic hematopoietic cell transplantation promotes T-cell activation and is inversely associated with an EZH2-ID3 signature

Vitamin D promotes a shift from a proinflammatory to a more tolerogenic immune state in allogeneic hematopoietic cell transplant (HCT) recipients. The dominant mechanism responsible for this shift has not been elucidated. We took a multifaceted approach to evaluating the clinical and immunologic impact of low vitamin D levels in 53 HCT recipients. We used 28-plex flow cytometry for immunophenotyping, serum cytokine levels, T-cell cytokine production, and T-cell whole genome transcription. The median day-30 vitamin D level was 20 ng/mL, and deficiency was common in younger patients undergoing myeloablative transplantation. Low vitamin D levels were associated with a high CD8/Treg ratio, increased serum levels and T-cell production of proinflammatory cytokines, and a gene expression signature of unrestrained T-cell proliferation and epigenetic modulation through the PRC2/EZH2 complex. Immunophenotyping confirmed a strong association between high levels of vitamin D and an activated EZH2 signature, characterized by overexpression of ID3, which has a role in effector T-cell differentiation. Our findings demonstrate the critical role of vitamin D in modulating T-cell function in human GVHD and identify a previously undescribed interaction with EZH2 and ID3, which may impact effector differentiation and has implications to cell therapies and other forms of cancer immunotherapy. © 20XX American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.
Safety Control of Completely Observed Markov Chains

In this paper we introduce and study the notion of safety control of stochastic discrete event systems (DESs), modeled as controlled Markov chains. For non-stochastic DES’s, modeled by state machines or automata, safety is specified as a set of forbidden states, or equivalently by a binary valued vector that imposes an upper bound on the set of states permitted to be visited. We generalize this notion of safety to the setting of stochastic DESs by specifying it as an unit-interval valued vector that imposes an upper bound on the state probability distribution vector. Under the assumption of complete state observation, we identify (i) the set of all state feedback controllers that satisfy the safety requirement for any given safe initial state probability distribution, and (ii) the set of all safe initial state probability distributions for a given state feedback controller.
The Power of Peers: New Ways for Students to Support Students

The idea that students can learn from each other is an old one indeed, having been traced as far back as Aristotle’s use of student leaders or archons.1 The peer group has been recognized as a powerful influence in undergraduate education, an assertion supported by a considerable amount of research over the years.2 In this chapter, we present two contemporary versions of peer group programs––both involving digital technologies—and by listening to student voices attempt to gain greater understanding as to how and why “peer teaching” can be transformative.
Who is concerned about what? a study of american, chinese and indian users' privacy concerns on social network sites

We present a study that investigates American, Chinese, and Indian social networking site (SNS) users' privacy attitudes and practices. We conducted an online survey of users of three popular SNSs in these countries. Based on 924 valid responses from the three countries, we found that generally American respondents were the most privacy concerned, followed by the Chinese and Indians. However, the US sample exhibited the lowest level of desire to restrict the visibility of their SNS information to certain people (e.g., co-workers). The Chinese respondents showed significantly higher concerns about identity issues on SNS such as fake names and impersonation.
Attenuated processing of epidermal growth factor in the face of marked degradation of transforming growth factor-α

T3M4 human pancreatic carcinoma cells avidly bound and internalized 125I-labeled epidermal growth factor (EGF) but did not readily degrade the ligand. Pulse-chase experiments in which the cell-bound radioactivity was allowed to dissociate into the incubation medium in the presence of unlabeled EGF indicated that the majority of the released 125I-EGF consisted of intact EGF and a slightly processed species that readily bound to the cell. Omission of unlabeled EGF during the chase period markedly decreased the amount of radioactivity in the incubation medium, mainly as a result of the rebinding of EGF to the cells. In contrast, T3M4 cells readily degraded 125I-labeled transforming growth factor-alpha (TGF-alpha), and the released radiolabeled products did not rebind to the cells. Both ligands were released from T3M4 cells under acidic conditions, complete dissociation occurring at a pH of 4.5 for EGF, and a pH of 6.5 for TGF-alpha. A 431 human epidermoid carcinoma cells and ASPC-1 human pancreatic carcinoma cells also failed to extensively degrade 125I-EGF, whereas Rat-1 fibroblasts markedly degraded the growth factor. As in the case of T3M4 cells, ASPC-1 cells extensively degraded 125I-TGF-alpha. Degradation of either ligand was blocked by the lysosomotropic compound methylamine in all the tested cell lines. Immunoprecipitation of the EGF receptor with specific polyclonal antibodies and Western blot analysis revealed the anticipated 170-kDa protein in T3M4 cells. Both EGF and TGF-alpha enhanced EGF receptor degradation, but TGF-alpha was less effective than EGF. These findings indicate that in certain cell types EGF and TGF-alpha may be differentially processed.
epsilon-Support Vector and Large-Scale Data Mining Problems

Data mining and knowledge discovery has made great progress during the last fifteen years. As one of the major tasks of data mining, classification has wide business and scientific applications. Among a variety of proposed methods, mathematical programming based approaches have been proven to be excellent in terms of classification accuracy, robustness, and efficiency. However, there are several difficult issues. Two of these issues are of particular interest of this research. The first issue is that it is challenging to find optimal solution for large-scale dataset in mathematical programming problems due to the computational complexity. The second issue is that many mathematical programming problems require specialized codes or programs such as CPLEX or LINGO. The objective of this study is to propose solutions for these two problems. This paper proposed and applied mathematical programming model to classification problems to address two aspects of data mining algorithm: speed and scalability.
Chapter 3 Hyperbolic dynamical systems

Publisher Summary This chapter outlines important results in the theory of uniformly hyperbolic dynamical systems on compact spaces as well as its extension to nonuniformly hyperbolic systems and to indicate techniques used in the development of the basic theory. Accordingly, there are comments on possible methods of proof in the earlier parts, whereas later portions give an impressionistic view of several main developments of the subject. The chapter focuses on various aspects of hyperbolicity. There are two intertwined strands of the history of hyperbolic dynamics: Geodesic flows on one hand and hyperbolic phenomena ultimately traceable to some application of dynamical systems. The chapter presents definitions and basic examples as well as the theory of stable and unstable laminations. It describes the two main methods for proving the stable/unstable manifolds theorem, the Hadamard and Perron–Irwin methods.
Development of mm-wave dual-frequency multilayer antenna arrays on liquid crystal polymer (LCP) substrate

The development of mm-wave dual frequency antenna arrays has been presented in multilayer LCP technology. Two 2times2 arrays operating at 14 and 35 GHz respectively have been designed and their impedance characteristics have been validated with measurements. These arrays can be integrated with 3D modules containing integrated circuits, filters and embedded passives to realize a complete system-on-package (SOP) based RF front end
Locally weighted learning for control

Lazy learning methods provide useful representations and training algorithms for learning about complex phenomena during autonomous adaptive control of complex systems. This paper surveys ways in which locally weighted learning, a type of lazy learning, has been applied by us to control tasks. We explain various forms that control tasks can take, and how this affects the choice of learning paradigm. The discussion section explores the interesting impact that explicitly remembering all previous experiences has on the problem of learning to control.
A VLA Radio Continuum Survey of Active Late-Type Giants in Binary Systems: Preliminary Results

We have made a sensitive survey at 6 cm of “active” G and K giants in binary systems, including the so-called Long-Period RS CVn stars. The systems observed have orbital periods in the range of ~10 to more than 100 days, and are judged to be “active” on the basis of their pronounced chromospheric and transition region emission lines and (where available) strong X-ray emission compared to single giants of similar spectral type. Our results to date show that strong radio continuum emission at centimeter wavelengths is a common but not universal property of this class of stars. On the basis of our VLA data and those obtained in a recent, less sensitive survey by Mutel and Lestrade, we discuss possible correlations between radio luminosity and other properties, such as X-ray luminosity, rotational period, and type of companion. Binary systems detected for the first time as radio continuum sources include 12 Cam (KO III + ?; Porb = 80d.2), HD 185510 (KO III-IV + sdB; Prot = 25d), 29 Dra (K0-2 III + wd; Prot = 31d), and FF Aqr (G8 III-IV + sdB; Porb = 9d21). Sensitive upper limits are presented for five other systems including the closest Long Period RS CVn binary, α Aur (G6 III + F9 III; Porb - 104d).
DNA Sequence Analyses Support the Role of Interrupted Gap Repair in the Origin of Internal Deletions of the Maize Transposon, MuDR

Previous research has demonstrated that the autonomous Cy transposon can activate the excision of Mu transposons. To determine the relationship between Cy and the more recently described autonomous Mu transposon, MuDR, a Cy transposon inserted at the mutable a1 allele, a1-m5216, was isolated and cloned. DNA sequence analyses established that this Cy insertion is identical to MuDR (Mu9, GenBank accession No.: m76978.gb_pl). Therefore, Cy will henceforth be termed MuDR:Cy. Defective derivatives of MuDR:Cy were isolated that had lost their capacity to activate their own excision or the excision of a Mu7 transposon. Most of these derivatives are nonautonomous transposons because they can excise, but only in the presence of unlinked MuDR:Cy transposons. Physical mapping and DNA sequence analyses have established that six of these defective derivatives carry internal deletions. It has been proposed previously that such deletions arise via interrupted gap repair. The DNA sequences of the break points associated with all four sequenced deletions are consistent with this model. The finding that three of the excision-defective derivatives carry deletions that disrupt the coding region of the mudrA (but not the mudrB) transcript supports the view that mudrA plays a role in the excision of Mu transposons.
Computational Design and Performance of the Fast Ocean Atmosphere Model, Version One

The Fast Ocean Atmosphere Model (FOAM) is a climate system model intended for application to climate science questions that require long simulations. FOAM is a distributed-memory parallel climate model consisting of parallel general circulation models of the atmosphere and ocean with complete physics paramaterizations as well as sea-ice, land surface, and river transport models. FOAM's coupling strategy was chosen for high throughput (simulated years per day). A new coupler was written for FOAM and some modifications were required of the component models. Performance data for FOAM on the IBM SP3 and SGI Origin2000 demonstrates that it can simulate over thirty years per day on modest numbers of processors.
Phases, Reflexives, and Definiteness

This paper investigates a puzzling correlation between two seemingly disparate phenomena: the crosslinguistic distribution of reflexive possessives and definiteness marking. As observed in Reuland 2007, 2011 and supported here by additional crosslinguistic evidence, reflexive possessives are available only in languages that either lack definiteness marking or encode definiteness postnominally. Languages that have prenominal (article-like) definiteness marking, on the other hand, systematically lack reflexive possessives. I argue that such facts support a particular approach to reflexive binding—specifically, one that has the following properties: (i) binding domains are stated in terms of phases, (ii) in addition to CPs and vPs, DPs are phases, and (iii) DP is not universal. I closely examine another robust crosslinguistic correlation regarding definiteness marking—Boskovic's (2008) Left Branch Extraction generalization—and show how it directly follows from the key assumptions of the analysis. I situate my proposals within a broader context of the phase theory, arguing that the syntactic representation of (in)definiteness is the crucial factor in determining the phasehood status of nominal categories. I extend my analysis to the clausal domain and discuss it in the context of languages that allow reflexives in the subject position.
Selective Search for Global Optimization of Zero or Small Residual Least-Squares Problems: A Numerical Study

In this paper, we consider approximating global minima of zero or small residual, nonlinear least-squares problems. We propose a selective search approach based on the concept of selective minimization recently introduced in Zhang et al. (Technical Report TR99-12, Rice University, Department of Computational and Applied Mathematics MS-134, Houston, TX 77005, 1999). To test the viability of the proposed approach, we construct a simple implementation using a Levenberg-Marquardt type method combined with a multi-start scheme, and compare it with several existing global optimization techniques. Numerical experiments were performed on zero residual nonlinear least-squares problems chosen from structural biology applications and from the literature. On the problems of significant sizes, the performance of the new approach compared favorably with other tested methods, indicating that the new approach is promising for the intended class of problems.
Hospital Admission for Xanthine Toxicity

A follow-up study of 35,909 outpatients who filled more than 220,000 prescriptions for theophylline over 9 years revealed 30 hospitalizations for xanthine toxicity. The overall estimated incidence rate of 7.8/10,000 person-years at risk indicates that in this population, hospitalization for xanthine toxicity is a relatively rare event.
Simple consistent estimation of the coefficients of a linear filter

Abstract A simple procedure is proposed for estimating the coefficients {ψ} from observations of the linear process X1=∑xJ=0ψJZ1−j, 1=1,2… The method is based on the representation of X1 in terms of the innovations, Xn−Xn, n=1,…, 1, where Xn is the best mean square predictor of Xn is span {X1,…X0−1}. The asymptotic distribution of the sequence of estimators is derived and its applications to inference for ARMA processes are discussed.
Electrical Conductivity of Multicomponent Systems During Ohmic Heating

During ohmic heating, the heating rate of a product depends on its electrical conductivity, a temperature dependent property. The electrical conductivity of the individual components in a multicomponent food system was determined over the entire sterilization temperature range (25−140°C). The product selected was chicken chowmein, composed of chicken, celery, mushrooms, water chestnuts, bean sprouts, and chowmein-style sauce. A device was developed to measure electrical conductivities of the components over the required temperature range. Results showed that the sauce (2.1 S/m at 27°C to 10.8 S/m at 140°C) was much more conductive than the solid components, i.e., celery (0.1 S/m to 3.4 S/m), water chestnut (0.1 S/m to 2.8 S/m), mushrooms (0.2 S/m to 1.4 S/m), bean sprouts (0.2 S/m to 1.5 S/m) and chicken (0.6 S/m to 3.4 S/m). Variation in electrical conductivity was also observed between different samples of the same component.
Interferon Decreases the Growth Inhibition of Mycobacterium avium-intracellulare Complex by Fresh Human Monocytes but Not by Culture-Derived Macrophages

Using a rapid radiolabel assay, monocytes derived from the peripheral blood of normal donors were found to kill 40%-92% of inoculated Mycobacterium avium-intracellulare complex (MAC), an opportunistic pathogen commonly found in AIDS patients. However, bactericidal activity was significantly lower in 4-day culture-derived macrophages compared with matched monocyte cultures. The addition of interferon-gamma (IFN-gamma) to monocytes was found to inhibit the bactericidal activity of fresh monocytes. The number of bacteria recovered from fresh monocytes exposed to IFN-gamma was significantly higher than that in control cultures with MAC alone, suggesting that intracellular MAC growth could be stimulated by IFN-gamma. This enhancement of MAC survival and growth by IFN-gamma was not observed when culture-derived macrophages were used. Similar results were obtained with IFN-alpha/A2. These results indicate, therefore, that the innate efficiency of mycobacterial killing by monocytes can be down-regulated by IFN, but macrophages are not significantly affected.
The construction of claims in visual argumentation

(1996). The construction of claims in visual argumentation. Visual Communication Quarterly: Vol. 3, No. 2, pp. 9-13.
Localization of Frontier Orbitals on Anatase Nanoparticles Impacts Water Adsorption

We present a computational investigation of spherical anatase nanoparticles with size ranging from 1.5 to 2.4 nm using density functional theory. Our results show that structural changes only occur within one or two unit cells from the surface regardless of the size of the nanoparticle. Hence, as the size of the nanoparticle increases, the effect of surface reconstruction penetrating into the interior obviously decreases and anatase nanoparticles rapibly obtain bulk-like structure for increasing size. Analysis of the nanoparticles in our work indicates that the frontier orbitals (so-called HOMOs) are mostly localized on low-coordinated Ti atoms which are located on corner positions of nanoparticles. These corner positions solely consist of 4-coordinated Ti atom lack of bridge oxygen atoms. These low-coordinated positions are the most energetically favored adsorption sites for water. The frontier orbitals located at these low-coordinated Ti sites become more localized with increased nanoparticle size resul...
Exploiting Synchronization Properties of Correlated Electron Devices in a Non-Boolean Computing Fabric for Template Matching

As complementary metal-oxide-semiconductor (CMOS) scaling continues to offer insurmountable challenges, questions about the performance capabilities of Boolean, digital machine based on Von-Neumann architecture, when operated within a power budget, have also surfaced. Research has started in earnest to identify alternative computing paradigms that provide orders of magnitude improvement in power-performance for specific tasks such as graph traversal, image recognition, template matching, and so on. Further, post-CMOS device technologies have emerged that realize computing elements which are neither CMOS replacements nor suited to work as a binary switch. In this paper, we present the realization of coupled and scalable relaxation-oscillators utilizing the metal-insulator-metal transition of vanadium-dioxide (VO2) thin films. We demonstrate the potential use of such a system in a non-Boolean computing paradigm and demonstrate pattern recognition, as one possible application using such a system.
Curriculum and Course Organization for Dairy Science

Summary An attempt has been made to outline methods whereby students in dairy production can attain necessary specialization in the biological sciences, without ignoring the importance of a liberal education. Our aim should be to train dairymen in a manner which, in addition to giving them competence, will enable them to take their place in society and to provide intelligent leadership.
Probability and expectation inequalities

This paper introduces a mathematical framework within which a wide variety of known and new inequalities can be viewed from a common perspective. Probability and expectation inequalities of the following types are considered: (a)P(ZeA)≧ P(Z′eA) for some class of setsA, (b)ℰk(Z)≧ℰk(Z′) for some class of functionsk, and (c)ℰl(Z)≧ℰk(Z′) for some class of pairs of functionsl andk. It is shown, sometimes using explicit constructions ofZ andZ′, that, in several cases, (a) ⇔ (b) ⇔ (c); included here are cases of normal and elliptically contoured distributions. A case where (a) ⇒ (b) ⇔ (c) is studied and is expressed in terms of“n monotone” functions for (some of) which integral representations are obtained. Also, necessary and sufficient conditions for (c) are given.
Photoelectric cross sections for ions scaled from their neutral atoms

Abstract Removal of outer electrons from an atom does not significantly change the potential and wave functions over the region where the wave function of the remaining bound electrons is large. This explains why the partial cross sections of an ion are similar to those of its neutral atom but truncated at the ion's threshold. Scaling by the wave-function-effective-Z can significantly improve the accuracy of the ion partial cross sections.
Laparoscopic splenectomy for hairy cell leukemia in pregnancy.

Objective. We present a successful case of laparoscopic splenectomy for a massively enlarged spleen at 25 weeks of gestation for hairy cell leukemia in pregnancy in a woman with initial hemoglobin of 4.3 gm/dl and platelet count of 18,000/mm3. Study Design. Case report. Results. This report provides an approach to management that may be applicable in those cases where thrombocytopenia or other clinical imperatives preclude delaying treatment till after pregnancy. Conclusion. Hairy cell leukemia is a clonal B-Cell malignancy, for which there is very limited experience worldwide for its management when it occurs during pregnancy. Laparoscopic splenectomy should be considered as a therapeutic option, even with a significantly enlarged spleen, in order to avoid the risks of fetal exposure to chemotherapeutic agents. Unique considerations relating to pregnancy are highlighted.
Assessing terrorist risk and FDI using relative information measures

Recent research has explored the determinants of terrorism and the impact that terrorist activity has on a country. However, to date, no research has examined what specific aspect of terrorist risk most significantly impacts a country's ability to operate in the global market. Using the five sub-indices of the World Market Research Center's Global Terrorism Index, this study explores how the different dimensions of terrorist risk impact the inflow of Foreign Direct Investment (FDI) using a Shannon information measure of relationship. The results of this research suggest that a country's proven ability to prevent terrorist activity has the most significant impact on investment decisions in regard to FDI.
RF Limiter Metamaterial Using p-i-n Diodes

We present the design and experimental implementation of an RF limiter metamaterial using a sheet of nonlinear metamaterials. We demonstrate that complementary electric inductive-capacitive resonators loaded with nonlinear p-i-n diodes can act as RF limiter unit cells. We design and fabricate limiter metamaterials and compare them to traditional circuit limiters. Our limiter metamaterial exhibits a minimum insertion loss under 3 dB, a maximum decrease in transmission of 6.95 dB and broadband performance, with a minimum decrease in transmission of 3 dB over 18% bandwidth. The limiter metamaterial is suitable for a wide variety of practical applications requiring protection of sensitive devices from high power.
The Perils of Politics: Why Staying Apolitical is Good for Both the U.S. Military & the Country

Abstract This article seeks to answer several vital questions about contemporary American civil- military relations. For example, why might the most professional military in United States history seem to be especially likely to engage in public dissent and advocacy? Why might political dissent and activity hold appeal for current and upcoming generations of military officers? And, how can present day officers be persuaded that retaining an apolitical ethos is fundamental to the American military, not just because of tradition but because public dissent can do real damage to the military institution and to the country it serves?
On near-wall turbulent flow modelling

The behavior of various terms in the Reynolds-stress transport equations is evaluated in view results of near-wall turbulence characterizations which show that all components of the velocity-pressure gradient correlation vanish at the wall. A methodology for deriving an asymptotically correct model of the velocity-pressure gradient correlation is proposed, and a model capable of approaching the high-Reynolds number model for pressure distribution far from the wall is derived. A parametric study of the model constants introduced by the near-wall closure reveals that one constant in the dissipation-rate equation is Reynolds number-dependent; with this modification, excellent agreement is obtained with measured and simulated near-wall turbulence statistics.
Radar Rainshower Growth Histories and Variations with Wind Speed, Echo Motion, Location and Merger Status

Abstract Data from rainshowers observed by the WSR-57 radar at the NOAA National Hurricane Center in Miami were tape-recorded during three recent summers as part of the Florida Area Cumulus Experiment (FACE). Past studies of convective clouds in the 13 × 1033 km2 FACE target area have indicated that enhancement of rainfall, following silver iodide seeding, was favored on those days that had light winds in the lower troposphere, along with some movement of rainshower echoes. In this study, we investigated the effect of wind speeds above and below 3 m s−;1 and, alternatively, the effect of echo motion (or stationarity) on the behavior of radar-observed rainshower echoes that were over water or over land, that had undergone merger with other echoes or had never merged, as functions of time of day and of echo growth cycle. We ignored any alterations in echo behavior that may have been the result of cloud seeding activities that were conducted over the target area on half of the afternoons. PPI radar scans wer...
Quantitative Determination of Chitosan and the Percentage of Free Amino Groups

Chitosans were quantified with ninhydrin, a reagent normally used for recognizing and quantifying amino groups. The reaction was time dependent and there was no effect when different acids were added to the mixture. This method was used to determine the percentage of free amino groups in chitosans of different origins.
Sol−Gel Synthesis and Hydrothermal Processing of Anatase and Rutile Titania Nanocrystals

The alkoxide sol−gel synthesis of nanostructured TiO2 has been studied systematically to examine the processing parameters that control crystallite size and phase. Nonagglomerated, ultrafine anatas...
Effect of dietary fluoride on selenite toxicity in the rat.

Three factorial experiments were conducted to determine if high dietary fluoride (F) would inhibit selenite toxicity in rats. Initially, three levels of selenite (0.05, 3, and 5 mg/kg diet) were matched against three levels of F (2, 75, and 150 mg/kg diet). Fluoride failed to prevent the depressive effect of selenite on 8-wk food intake and body wt gain. Selenium (Se) concentration of plasma and kidney and enzymatic activity of whole blood glutathione peroxidase (GSH-Px) were also unaffected by F. Liver Se concentration, however, was slightly (12%) but significantly (p<0.025) reduced when the highest F and Se levels were combined. Fluoride (150 mg/kg) appeared to reduce liver selenite toxicity (5 mg/kg). Therefore, further study focused on liver histology with treatments that eliminated the middle levels of selenite and F. Fluoride prevented the hepatic necrosis seen in selenite-toxic rats. Similar histological lesions were not observed for kidney or heart. Fluoride partially (26%) but significantly (p<0.025) reduced thiobarbituric-reactive substances in selenite-toxic rats, but there was no F effect on intracellular distribution of liver Se, glutathione levels in liver and kidney, or on liver xanthine oxidase activity. Overall, the protective effect of F on selenite toxicity appears to be confined to liver pathology. The exact mechanism for this effect, however, remains unclear.
Cannabis-induced Koro in Americans.

Aims. Koro, an acute panic reaction related to the perception of penile retraction, was once considered limited to specific cultures. The disorder has appeared as part of a panic response to cannabis, but only in citizens of India. This study looked for cannabis-induced Koro in Americans. Design. Given the relative rarity of cannabis-induced Koro, this work focused on individual case studies. Participants. Over 70 men responded by phone to report negative reactions to cannabis. Three of them (Caucasians aged 22-26 with years of experience with cannabis) spontaneously mentioned experiencing symptoms of Koro after smoking marijuana. Findings. All three cases occurred after participants had heard about cannabis-induced Koro and used the drug in a novel setting or atypical way. Two of the men had body dysmorphia, which may have contributed to symptoms. All three decreased their cannabis consumption after the Koro experience. Conclusions. Koro, particularly cannabis-induced Koro, is not limited to Eastern cultures. Several factors may interact to create symptoms. These include previous knowledge of cannabis-induced Koro, the use of marijuana in a way that might heighten a panic reaction, and poor body image. In addition, these cases confirm previous work that shows that negative reactions to drugs can attenuate their use.
Contribution of the Adrenal Cortex to Renal and Renoprival Hypertension

Association of the adrenal cortex with renal hypertension lead to the conclusion that several mechanisms are operating. First, hypertension is not, or is poorly sustained in true adrenal failure, and mild failure seems to impair vascular responsiveness. This indicates a permissive function of the adrenal in renal hypertension. Furthermore, degrees of renal injury or of hypercorticoidism which are not of themselves very pressor may cause severe hypertension when they are added together. This additive aspect is probably closely related to the sensitizing effect of adrenal steroids on renal pressor activity and underlies the so-called renin-DCA syndrome. It may involve not only an enhanced pressor responsiveness but also a weakening of vessel walls. Lastly, the effects of renin and renal hypertension on the zona glomerulosa suggest that the renal pressor system has a direct effect on the adrenal cortex which would tend to add cortical pressor to existing renal pressor activity and thus sustain renal hypertension.
Neuropathy target esterase in hens after sarin and soman

To estimate the potential of small doses of sarin (types I and II) and soman to cause delayed neuropathic effects, 400, 200, 61, and 0 micrograms/kg of sarin-I, 280, 140, 70, and 0 micrograms/kg of sarin-II, and 14.2, 7.1, 3.5, and 0 micrograms/kg of soman by gavage were compared with 510 mg/kg tri-o-cresyl phosphate (TOCP) in 14- to 18-month-old SPF white leghorn hens (4/dose) protected with atropine (100 mg/kg). The neuropathy target esterase (NTE) activity 24 hr after dosing was determined in brain, spinal cord, and lymphocytes and in plasma and brain for cholinesterase and carboxylesterase. None of the compounds showed statistically significant NTE decreases. Sarin-II showed a dose-related trend in the lymphocyte NTE (to 33% of control at 280 micrograms/kg), suggesting that longer exposure to lower doses might cause a cumulative neurotoxic insult. All of the agents decreased the activity of plasma and brain cholinesterase and carboxylesterase. Using more than 70% inhibition of brain NTE as a biochemical predictor of delayed neuropathy, sarin and soman appear unable to cause delayed neuropathy at nonlethal doses within this protocol.
Properties of an adiabatic shear-band process zone

Abstract The formation of adiabatie shear bands is examined with an approximate analytic model. The shear band is viewed as a propagating feature with a well-defined front. The shear band is further partitioned into a shear-band process zone within which most of the adiabatic heating and shear stress relaxation occurs, followed by a quasi-steady zone within which little dissipation occurs. Although a one-dimensional analysis of the shear-band dynamics is initially pursued, the analysis is then used to calculate properties of the inherently two-dimensional shear-band process zone. The length and width of the process zone are calculated along with the shear displacement. The model is further used to calculate the energy dissipation within the shear-band process zone and the concept of a shear-band toughness is introduced. The flow field within the vicinity of the process zone is also examined. Calculated properties of the shear-band process zone compared well with available experimental data.
Cell mechanics: Forced to branch out

Migrating cells are capable of actively opposing external forces. A study of the polymers that mediate cell motility indicates that they effect this response by branching where bent under force.
The Beginnings of Quantum Nonlinear Optics and of Optical Phase Conjugation; Answers to Communication Challenges

The advent of quantum mechanics led early in the 20th century to a rigorous quantitative description of the phenomenon of spontaneous emission from excited atomic states. The fields of nonlinear electronics and Nonlinear Optics have gone through a conceptually similar process. The quantum formulation of the optical parametric amplifier and oscillator led to the prediction and soon afterwards to the demonstration of parametric spontaneous fluorescence (PSF).
Laminar and areal differences in the origin of the subcortical projection neurons of the rat somatosensory cortex.

Fluorescent retrograde tracing techniques were employed in a double-labelling paradigm to determine the distribution of corticospinal, corticotectal, and corticotrigeminal projection neurons in layer Vb of the adult and neonatal rat somatosensory cortex. The double-labelling paradigm allowed a direct comparison of the cortical distribution of neurons projecting to each target and identification of neurons projecting to more than one target. In the adult rat, each population of projection neurons was found to have a unique laminar and/or areal distribution. Corticospinal projection neurons were located throughout the width of layer Vb in the medial granular portion of somatosensory cortex, while corticotrigeminal projection neurons were distributed throughout the width of layer Vb in the more laterally located dysgranular portion of somatosensory cortex. Corticotectal projection neurons were located more superficially in layer Vb than either corticospinal or corticotrigeminal projection neurons and found scattered throughout both dysgranular and granular somatosensory cortex. Each combination of subcortical injections also resulted in double labelling a small percentage of uniquely distributed neurons. These distribution differences coupled with measurements of cell size allowed us to identify the parent population of the dual projection neurons. Subpopulations of corticotectal neurons also project to the brainstem trigeminal complex and to the spinal cord. Subpopulations of corticotrigeminal neurons also project to the spinal cord, and a proportion of corticotrigeminal neurons projects to at least two targets within the brainstem trigeminal complex (nucleus principalis and subnucleus interpolaris). In the adult rat, corticospinal neurons (as defined by either laminar position or somal size) did not appear to give off collaterals to either the superior colliculus or brainstem trigeminal complex. In the neonatal rat, double-labelled neurons which project to both the spinal cord and the tectum are distributed throughout the full width of layer Vb, rather than restricted to the superficial portion of the layer as in the adult rat. Further, it appears as if the ontogenetic change in the laminar distribution of corticospinal and tectal projection neurons is achieved by mechanisms of selective process elimination rather than cell death. These results are discussed in terms of both the developmental factors which may contribute to the discrete distribution of cortical projection neurons found in the adult and the functional significance of bifurcating projection neurons.
Addressing the needs of patients and their family: conclusion.

Four steps, which have been clearly described in the previous texts, can be used to help families of patients with Dravet syndrome. The first is the right diagnosis. The article by I. Scheffer reviewed the clinical presentation of Dravet syndrome. Diagnosis at the onset is sometimes difficult. In doubtful cases, when convulsive seizures are repeated and prolonged, I advocate early treatment under the presumption that it may be Dravet syndrome, so that complications such as status epilepticus or inappropriate use of antiepileptic drugs may be avoided. The occurrence of photosensitivity is difficult to quantify because it is variable and is dependent on the inclusion or exclusion of pattern-sensitivity and eye closure effect. Differences may exist between countries, but in our experience it is much more frequent than 10% of cases. The second step is use of the appropriate treatment. As shown by R. Nabbout, the development of stiripentol provided great progress in treatment, since it is the only drug that has demonstrated efficacy in double-blind clinical studies. I hope ongoing studies will lead to its wider use in more patients and that other new drugs will be developed. The third step is addressing the burden of the disease on the families. P. Camfield, in his presentation of family problems, has considered this aspect in a realistic way. In the most severe patients, the placement of an indwelling catheter is undoubtedly a means of preventing status epilepticus. The designation of one parent to be “on call” for the affected child and the other for the siblings is another good suggestion. The fourth step is understanding the factors responsible for the cognitive decline, which were explained by R. Guerrini, and providing the families with all possible assistance in order to decrease this risk. The distribution of cognitive levels depends on the time when patients were evaluated. Update data tend to indicate that those recently diagnosed appear to have less severe decline than those diagnosed long ago, perhaps as a result of better patient management.
Seeds of engagement: design conversations for educational change

Change models revolve around communication between designers and adopters, but the processes involved are far less often the focus of our scholarship. We present design conversation as an inclusive, participatory avenue to designing educational changes and as a legitimate focus of design scholarship. Design conversation sits apart from other forms of communication, such as dialectic conversation and discussions, in which opinions are staked out and defended. Design conversation is a group endeavour where a group searches for common meaning and designs a new entity. Design conversation is linked here to the need for a systems approach to educational change. We discuss this need; describe the nature of design conversation, its theoretical foundation in systems thinking and its use for educational systems design. The direction and nature of communication in selected change models is then compared to design conversation and, finally, its implications for educational systems design are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Stereospecific Displacement of Sulfur from Chiral Centers. Activation via Thiaphosphonium Salts.

Abstract The first general method for direct displacement of sulfur from chiral carbon centers has been developed. Chiral mercaptans are readily converted to the corresponding thiaphosphonium salts by treatment with t-butyl hypochlorite and hexamethylphosphorous triamide. Metathesis with ammonium hexafluorophosphate provides stable, isolable, crystalline salts which undergo clean nucleophilic diplacement with a variety of heteroatom and carbon based nucleophiles, affording products in which the stereochemistry has been inverted.
Renal Cation Excretion in the Hypocalcemic Premature Human Neonate

We describe the interrelationship of the urinary excretion of sodium, calcium, magnesium, and phosphorus in 22 hypocalcemic premature neonates whose mean gestational age was 31.7 wk. Strong relationships between sodium excretion and calcium excretion (r = 0.85), sodium excretion and magnesium excretion (r = 0.76), sodium excretion and phosphorus excretion (r = 0.94) were demonstrated. Sodium intake during the 84-hr study period ranged from 2.9 to 34.5 mEq/kg and calcium intake during the same period ranged from 0 to 152.3 mg of elemental calcium per kg. The intakes of the other cations were negligible. All variables but phosphorus excretion (r = -0.55) were independent of calcium intake whereas sodium excretion (r = 0.76), calcium excretion (r = 0.72) magnesium excretion (r = 0.62), and phosphorus excretion (r = 0.53) were all correlated with sodium intake. Serum calcium concentration at the end of the study was unrelated to total calcium intake during the 84-hr study period, whereas it was negatively related to total sodium intake (r = -0.71).
Interaction of nitromethane with reduced hepatic microsomal cytochrome P-450.

Abstract Nitromethane interacts with sodium dithionite reduced rabbit liver microsomes to generate a difference spectrum characterized by maxima at 388, 423, 454 and 520 nm and minima at 405, 436, 480 and 550 nm. Spectral binding constants (Ks) of 0.306 ± 0.082 mM (Amax = 0.032 ± 0.004), 0.178 ± 0.029 mM (Amax = 0.040 ± 0.002), and 1.168 ± 0.250 mM (Amax = 0.035 ± 0.006) were calculated for the 388, 423 and 454 nm peaks respectively. These difference spectra are qualitatively different from those previously reported for aromatic nitro compounds [L. A. Sternson and R. E. Gammans, Drug Metab. Dispos.3, 266 (1975)]. Interaction of nitromethane with microsomes from rabbits pretreated with phenobarbital produced absorbance maxima and minima within 2 nm of the controls. Interaction of nitromethane with reduced microsomes from 3-methyl-cholanthrene (3-MC)-pretreated animals produced ferrohemochromes in which maximal absorbance changes were shifted to maxima at 384, 422, 451 and 514 nm and minima at 407, 433, 473 and 552nm. Peak-height ratios derived from difference spectra generated by the addition of 1 mM nitromethane to the sample cuvette were considerably different depending on whether the microsomes were obtained from control, phenobarbital- or 3-MC-pretreated rabbits and may indicate that phenobarbital, like 3-MC, induces qualitative changes in cytochrome P-450. Nitromethane apparently competes with carbon monoxide for a common binding site. Addition of nitromethane to CO-saturated microsomes reduced the magnitude of the 450 nm peak with a concomitant increase in the 423 nm peak of nitromethane. Similarly, addition of CO to reduced microsomes containing nitromethane caused reduction of the 423 nm peak of nitromethane with a corresponding increase of the 450 nm peak of CO. Nitromethane does not generate difference spectra with oxidized microsomes nor does it alter the Ks or Amax of aminopyrine, hexobarbital, aniline or zoxazolamine binding spectra. Nitromethane does inhibit the binding of the type II compound, nicotinamide. Addition of nitromethane to incubation flasks enhanced the metabolism of aniline while tending to inhibit the oxidative demethylation of ethylmorphine.