cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of Percutaneous Reduction and Pin Fixation in Chronic and Acute Pediatric Mallet Fractures

Introduction Although pediatric mallet fractures are more common than adult fractures, no techniques have focused on surgical fixation of pediatric mallet fractures. This study aims to describe the technique and results of percutaneous reduction and fixation in acute and chronic pediatric mallet fractures. Material and Methods This is a retrospective review of 59 pediatric mallet fractures treated with percutaneous wire fixation from 2007-2014; 43 were acute fractures and 16 were chronic (>4 weeks from injury). Surgical technique was identical for all fractures; …
Quantum dot to quantum dot Förster resonance energy transfer: engineering materials for visual color change sensing.

In this work, quantum dots (QDs) of various heterostructured compositions and shell thicknesses are used as Forster or fluorescence resonance energy transfer (FRET) donors and acceptors to optimize QD-QD FRET sensing through materials design. While several reports have highlighted the advantages of using QD-dye, rather than dye-dye, FRET in sensing applications, QD-QD FRET has lagged behind in development as a result of high background signal from direct acceptor excitation. However, in designing sensors for longitudinal studies, QD-dye sensors are limited by the photostability of the fluorescent dye. While fluorescence generally affords higher sensitivity than absorbance-based readouts, the instrumentation needed for detecting fluorescence can be expensive, motivating the development of sensors bright enough to be seen by eye or imaged with cheap consumer electronics. Harnessing the exceptional brightness of QDs, our study focuses on the development of QD-QD FRET pairs where color change is achieved for visual readout and instrument-free sensing. We demonstrate that bulk semiconductor material characteristics can be used to a priori predict and tailor the behavior of QD-QD FRET systems, and our findings show that it is possible to create QD donors that are brighter than their acceptors through concerted compositional and morphological choices in heterostructured QDs. This is significant for developing visual sensors, as we show that the most profound color change occurs when the direct acceptor emission is lower than that of the donor. Finally, the use of an optimal cadmium-free QD-QD FRET pair is presented in a pH sensor that shows a large range of pH-dependent color change with bright, instrument-free readout.
Deep learning model of somatic hypermutation reveals importance of sequence context beyond targeting of AID and Polη hotspots

B-cells undergo somatic hypermutation (SHM) of the Immunoglobulin (Ig) variable region to generate high-affinity antibodies. SHM relies on the activity of activation-induced deaminase (AID), which mutates C>U preferentially targeting WRC (W=A/T, R=A/G) hotspots. Downstream mutations at WA Polymerase {eta} hotspots contribute further mutations. Computational models of SHM can describe the probability of mutations essential for vaccine responses. Previous studies using short subsequences (k-mers) failed to explain divergent mutability for the same k-mer. We developed the DeepSHM (Deep learning on SHM) model using k-mers of size 5-21, improving accuracy over previous models. Interpretation of DeepSHM identified an extended DWRCT (D=A/G/T) motif with particularly high mutability. Increased mutability was further associated with lower surrounding G content. Our model also discovered a conserved AGYCTGGGGG (Y=C/T) motif within FW1 of IGHV3 family genes with unusually high T>G substitution rates. Thus, a wider sequence context increases predictive power and identifies novel features that drive mutational targeting.
Metabolism of Oxypurines In Man

Publisher Summary This chapter describes the synthesis of purine nucleotides and the transformation of these compounds to oxypurines. Purines are integral components of various fundamental biological entities. Their production and function are considered vital for life. Oxypurines are end products of purine metabolism. The enzymes that produce them are varied in location and nature. There are many pathological or physiologically abnormal conditions, which can lead to concomitant alterations in the metabolism of oxypurines. Oxypurines exhibit low solubility and their synthesis is not a necessary by-product of the vital biochemical reactions. Their production results in the ultimate loss from the body of purine moieties that are produced at great biochemical expense. The great bulk of the oxypurines released as a result of the action of hydrolytic enzymes normally, are ultimately oxidized to uric acid. The most common defect in oxypurine metabolism is manifested by hyperuricemia and hyperuricosuria.
A human challenge: discovering and understanding continental copepod habitats

Copepods have invaded an astonishing variety of aquatic and humid continental environments and microhabitats. The historical process of discovery and investigation of copepods in ephemeral, acid and thermal waters, subterranean waters and sediments, phytotelmata, humid soils, leaf litter, human-modified and artificial habitats, and other situations extends over about 130 years. The methods developed to collect in and study these habitats range from simple nets to elaborate pumping systems and diving techniques. Investigations of non-lacustrine continental environments have contributed greatly to the understanding of aspects of copepod biology such as reproduction, diapause and population dynamics. Questions regarding faunistics and biological diversity, biogeography, evolution, transport and introductions of alien species have also been informed by such studies. This article briefly reviews these topics, and provides detailed lists of records from some of the less well-known kinds of habitats.
The sounds of French: The International Phonetic Association

The following text is taken from the pamphlet entitled The Principles of the International Phonetic Association , published by the International Phonetics Association (1949 edition). A short history of the Association Phonetique Internationale The Association Phonetique Internationale (in English, International Phonetic Association , in German, Weltlautschriftverein ) was inaugurated in 1886, under the title of The Phonetic Teachers' Association , by a small group of language teachers in France who had found phonetic theory and phonetic transcription of value in connexion with their work, and who wished to popularise the methods that they had found so useful. A journal entitled Dhi Fonetik Titcer was started in May of that year, under the editorship of Paul Passy. It was a unique periodical, in that its contents were printed entirely in phonetic transcript. At first the Association concerned itself mainly with phonetics as applied to the teaching of English, but the membership was international from the very start. (Incidentally, Otto Jespersen became a member in June, 1886, Wilhelm Vietor in July, 1886, Henry Sweet and J. A. Lundell in September, 1886.) Soon a demand arose for phonetic texts in languages other than English, and for articles dealing with general phonetic problems.
Principles that Matter: Sustaining Software Innovation from the Client to the Web

Economic analysis often reviews the role of principles - such as respect for intellectual property rights - in driving innovation. Given the interdependent nature of innovation in information technology, three core principles have emerged that work together to ensure that complementary, interconnected products coexist and compete. These core principles are particularly important when applied to platforms, which have played a central role in enabling the development and distribution of the variety of applications and services that drive the popularity of software. The first principle focuses on enabling choice: firms should allow consumers and partners to have a real choice between complementary products and services from otherwise competing firms (e.g., a browser should enable a consumer to choose a home page provided by a competitor). The second principle focuses on opportunity: specifically, opportunity that is facilitated by giving developers platform access and the ability to innovate and build on platform technologies to create new products and services. The third principle focuses on interoperability: vendors should enable products to work together so customers can realize the full benefit of complementary products offered by competing vendors. Following this principle enables products to connect to each other in appropriately defined ways, and ensures that users can port their data between products securely and reliably. This paper reviews the rationale for these principles and examines their impact on competition in the cloud computing (“internet software”) environment.
Gene-Specific and Mitochondrial Repair of Oxidative DNA Damage

The Southern blot gene-specific DNA damage and repair assay is a robust and flexible method for quantifying many kinds of induced damage and repair with high reproducibility. Specific nicking and loss of a restricted DNA fragment at the site of induced damage is visualized by Southern blot and quantified against a control; since the blot is gene specific, only the damage of interest is measured. Here we show how the assay may be adapted to assess mitochondrial DNA (mtDNA) damage. In the mitochondrion, 8-oxoguanine is a significant oxidative lesion; in the laboratory, photoactivated methylene blue may be used to introduce this lesion into cells. Other lesions may also be studied by using different DNA damaging agents. We find that damage induction by methylene blue is consistently far greater in the mitochondrion than the nucleus. Thus advantageously, mitochondrial 8-oxoguanine repair may be studied without mtDNA isolation or preparation, which are processes known to induce DNA damage and skew measurements. This chapter gives detailed instructions for using methylene blue and the gene-specific repair assay to accurately measure mitochondrial oxidative damage and repair rates.
Public Choice and Environmental Policy: A Review of the Literature

This paper is a draft of a chapter for a forthcoming book, Research Handbook in Public Law and Public Choice, edited by Daniel Farber and Anne Joseph O'Connell, to be published by Elgar. It reviews the public choice literature on environmental policy making, first generally and then with respect to four fundamental environmental policy questions: (1) whether or not government action is warranted; (2) if it is, the scope and stringency of the government action, including the manner in which a bureaucracy will implement and enforce any statutory standards; (3) the level of government that assumes responsibility; and (4) the type of regulation, or regulatory instrument, that government employs. The review traces how public choice writing on these problems has been influenced by two evolutionary improvements in public choice thinking: (1) a shift from models that posit policy will always be dominated by concentrated economic interests to models that incorporate the possibility of broad-based citizen collective action under certain conditions; (2) a shift from models employing thick-rationality assumptions that take the preferences of actors to be defined exclusively in terms of their material self-interest, to models with thin-rationality assumptions that acknowledge the possibility that principled commitments, including to the general social welfare or to sound public policy, can form part of the preference set of many political actors. Empirical work has validated these theoretical and modeling improvements. The models that are emerging from these two shifts remain faithful to public choice's fundamental orientation toward envisioning a "politics without romance," and they persist in analyzing public decision making by understanding the individual motives for action. At the same time, they acknowledge a fuller range of possibilities from government action than the simpler but less accurate rent-seeking models do. The simpler models predict only grim results from government decision making, suggesting that government action routinely fails to address environmental problems constructively and does so primarily as a means of transferring wealth to powerful economic interests away from the rest of us. Under the improved models, government can be responsive to the public's interests and the general welfare when conditions are right. Public choice has always traced an intellectual lineage back to neoclassical market theory, which has made important contributions to environmental policy by developing a toolkit of environmental market-improving measures such as fees, pollution taxes, subsidies and cap-and-trade, along with analyzes of the pros and cons of each tool in light of the environmental problem to be addressed. Going forward, public choice research can make similar contributions to the study of how environmental policy is made if the newer public choice models are deployed to develop more systematic recommendations of feasible ways to improve the quality of governmental decision making.
On the degree of decomposition in linear programming

In the application of Dantzig-Wolfe decomposition to block-angular lin­ ear programming problems with R natural blocks. it is possible to have from 1 to R subproblems structurally while solving all R independent subproblems computationally. Early literature on the topic was inconclusive regarding the relative merits of such for­ mulations. This paper attempts clarification by characterizing the significance of the degree of decomposition as well as presenting extensive empirical results.
Nonlinear and fuzzy logic vibration control of flexible manipulators

Using nonlinear and fuzzy logic control techniques, we study vibration control of flexible manipulators. Nonlinear and fuzzy logic control laws are formulated to effectively damp vibrations of a flexible link using collocated piezoelectric actuators and sensors. Simulations show that each of the proposed controllers results in a fast and yet very well damped transient response superior to that achieved by a linear optimal controller.
The Cysteine Residue in the Carboxyl‐Terminal Domain of the m2 Muscarinic Acetylcholine Receptor Is Not Required for Receptor‐Mediated Inhibition of Adenylate Cyclase

Muscarinic acetylcholine receptors (mAChRs) share with many other receptors of the guanine nucleotide-binding protein-coupled receptor family a highly conserved cysteine residue in the putative cytoplasmic carboxyl-terminal region of the protein. Because elimination of this cysteine in the beta 2-adrenergic receptor has been reported to decrease functional responsiveness, we determined if this cysteine residue is essential for mAChR-effector coupling by replacing Cys457 of the m2 mAChR with glycine and expressing wild-type and mutant receptor in Chinese hamster ovary (CHO) cells. The mutant and wild-type receptors exhibited similar affinities for binding of muscarinic ligands. In addition, the mutation did not affect cell surface localization or receptor-mediated inhibition of adenylate cyclase. These results indicate that the cysteine residue in the carboxyl-terminal domain of the m2 mAChR is not required for ligand binding or mAChR-mediated inhibition of adenylate cyclase in CHO cells.
Conjunctions, Disjunctions and Lewisian Semantics for Counterfactuals

Consider the reasonable axioms of subjunctive conditionals (1) if p q 1 and p q 2 at some world, then p (q 1 & q 2) at that world, and (2) if p 1 q and p 2 q at some world, then (p 1 ∨ p 2) q at that world, where p q is the subjunctive conditional. I show that a Lewis-style semantics for subjunctive conditionals satisfies these axioms if and only if one makes a certain technical assumption about the closeness relation, an assumption that is probably false. I will then show how Lewisian semantics can be modified so as to assure (1) and (2) even when the technical assumption fails, and in fact in one sense the semantics actually becomes simpler then.
Dissecting glycoprotein quality control in the secretory pathway

In the early secretory pathway, asparagine-linked glycosylation facilitates the conformational maturation of diverse polypeptides by promoting their physical engagement with the glycoprotein-folding machinery. Misfolded glycoproteins are selectively eliminated from the endoplasmic reticulum by a stringent process of conformation-based quality control. Recent studies indicate that a small ensemble of oligosaccharide-processing enzymes and lectins use the asparagine-linked appendage to orchestrate the selective disposal of numerous transport-defective glycoproteins from the early secretory pathway. The glycan-based disposal system functions as an evolutionarily conserved terminal checkpoint in eukaryote genome expression. That the mechanisms by which glycoprotein substrates are recruited for degradation diverge at the level of signal recognition reflects a previously unappreciated component of cellular differentiation in higher eukaryotes.
Kinetic and spectroscopic studies of Tritrichomonas foetus low-molecular weight phosphotyrosyl phosphatase. Hydrogen bond networks and electrostatic effects.

Virtually all of the eukaryotic low-molecular weight protein tyrosine phosphatases (LMW PTPases) studied to date contain a conserved, high-pK a histidine residue that is hydrogen bonded to a conserved active site asparagine residue of the phosphate binding loop. However, in the putative enzyme encoded by the genome of the trichomonad parasite Tritrichomonas foetus, this otherwise highly conserved histidine is replaced with a glutamine residue. We have cloned the gene, expressed the enzyme, demonstrated its catalytic activity, and examined the structural and functional roles of the glutamine residue using site-directed mutagenesis, kinetic measurements, and NMR spectroscopy. Titration studies of the two native histidine residues in the T. foetus enzyme as monitored by 'H NMR revealed that H44 has a pK a of 6.4 and H143 has a pK a of 5.3. When a histidine residue was introduced in place of the native glutamine at position 67, a pK a of 8.2 was measured for this residue. Steady state kinetic methods were employed to study how mutation of the native glutamine to alanine, asparagine, and histidine affected the catalytic activity of the enzyme. Examination of k c a t /K m showed that Q67H exhibits a substrate selectivity comparable to that of the wild-type (WT) enzyme, while Q67N and Q67A show reduced activity. The effect of pH on the reaction rate was examined. Importantly, the pH-rate profile of the WT TPTP enzyme revealed a much more clearly defined acidic limb than that which can be observed for other wild-type LMW PTPases. The pH-rate curve of the Q67H mutant shows a shift to a lower pH optimum relative to that seen for the wild-type enzyme. The Q67N and Q67A mutants showed curves that were shifted to higher pH optima. Although the active site of this enzyme is likely to be similar to that of other LMW PTPases, the hydrogen bonding and electrostatic changes afford new insight into factors affecting the pH dependence and catalysis by this family of enzymes.
Designing mobile snack application for low socioeconomic status families

We developed four mobile phone prototype applications informed by theoretical models of behavior change to improve the snacking habits of low socioeconomic status (SES) families. Eight primary caregivers and 18 secondary caregivers from low SES backgrounds used the applications to evaluate their usability and usefulness. We found a schism between primary and secondary caregivers regarding whether the applications should be based on games, indicating a need to reconcile these differences to develop a system to support healthy family snacking. In addition, social context, understandable health abstractions, and sensitivity to health values are all important considerations when creating applications in a low SES context. This research contributes design implications for future applications intended to improve snacking habits in low SES families.
Recent applications of radio to the remote indication of meteorological elements

Lightweight radio transmitting equipment, carried aloft by balloons, is being used to obtain remote indications of meteorological elements, from the stratosphere. Such equipment also makes possible periodic observations from unattended stations in remote locations. In the past few years there has been increasing application of radio to the extension of the geographical boundaries within which routine weather observations may be made. Heretofore, weather observations were limited to those which could be obtained by human observers near the weather instruments. The use of special measuring devices which automatically translate the variations of the meteorological elements to be measured into corresponding radio signal variations has removed many of the practical limitations. Measurements may be obtained from any point where it is possible to locate the measuring and auxiliary equipment, and they may be recorded (automatically, if desired) at any convenient point within radio contact of the measuring point. Thus, upper-air observations may be obtained economically well into the stratosphere by sending aloft, attached to small balloons, meteorological instruments with associated miniature radio transmitting equipment. Also, periodic observations may be had from isolated locations such as mountain peaks, small islands, floating buoys, and the like, where unattended equipment may be serviced at infrequent intervals but where it would not be practicable to maintain an observation staff. The government's meteorological services are already making extensive use of the balloon-carried equipment (radio sondes), daily upper-air observations being obtained at a large number of land stations in continental United States, Alaska, and the Caribbean, and at shipboard stations in the Atlantic and Pacific. The use of automatic weather stations at remote isolated locations is just beginning, but already quite a number of installations are in project.
Small retailer strategies for battling the big boxes: a “Goliath” victory?

Purpose – The past 25 years have witnessed a dramatic rise in the dominance of big‐box retailers in the global retail sector and the decline of small retailers. The purpose of this paper is to explore how the intensity of competition with big box retailers moderates the relationship of strategy choice to expected growth.Design/methodology/approach – This study uses cross‐sectional survey data from a group of 199 small retailers in the USA. Hypotheses are tested using linear regression of expected growth on the use of three growth‐oriented strategies. These relationships are subjected to tests of the moderating effect of direct competition with big box retailers.Findings – This study shows that small retailers pursue strategies of offering previously unavailable goods or services, high quality, and better service to pursue future growth. The interaction effect of strategy with directness of competition with big box retailers, however, has a negative and significant effect on expected growth.Research limita...
“It's stuff that speaks to me”: Exploring the characteristics of digital possessions

Digital possessions are digital items that individuals distinguish from other digital items by specific qualities that individuals perceive the digital items to possess. Twenty-three participants were interviewed about their definitions of and relationships with digital possessions to identify the most salient characteristics of digital possessions and to inform preservation. Findings indicate that digital possessions are characterized as (a) providing evidence of the individual, (b) representing the individual's identity, (c) being recognized as having value, and (d) exhibiting a sense of bounded control. Furthermore, archival concepts of primary, secondary, and intrinsic values provide the frame for the defining characteristics. Although several findings from this study are consistent with former studies of material possessions and digital possessions, this study expands research in the area using the concept of digital possessions to inform preservation and by applying archival principles of value. Understanding the nature of the individual and digital item relationship provides potential to explore new areas of reference and outreach services in libraries and archives. As the nature of archival and library reference services evolves, some scholars have predicted that archives and libraries will play a part in helping individuals manage their personal collections An exploration of individuals' relationships with their digital possessions can serve as a starting point at which scholars can explore the potential of personal information management consulting as a new area of reference and information services, specifically for the preservation of personal digital material.
A roadmap for academic health centers to establish good laboratory practice-compliant infrastructure.

Prior to human clinical trials, nonclinical safety and toxicology studies are required to demonstrate that a new product appears safe for human testing; these nonclinical studies are governed by good laboratory practice (GLP) regulations. As academic health centers (AHCs) embrace the charge to increase the translation of basic science research into clinical discoveries, researchers at these institutions increasingly will be conducting GLP-regulated nonclinical studies. Because the consequences for noncompliance are severe and many AHC researchers are unfamiliar with Food and Drug Administration (FDA) regulations, the authors describe the regulatory requirements for conducting GLP research, including the strict documentation requirements, the necessary personnel training, the importance of study monitoring, and the critical role that compliance oversight plays in the process. They then explain the process that AHCs interested in conducting GLP studies should take prior to the start of their research program, including conducting a needs assessment and a gap analysis and selecting a model for GLP compliance. Finally, the authors identify and analyze several critical barriers to developing and implementing a GLP-compliant infrastructure at an AHC. Despite these challenges, the capacity to perform such research will help AHCs to build and maintain competitive research programs and to facilitate the successful translation of faculty-initiated research from nonclinical studies to first-in-human clinical trials.
401: Thrombin suppresses hCG production by human syncytiotrophoblast: A mechanism by which first trimester bleeding causes abortion

MECHANISM BY WHICH FIRST TRIMESTER BLEEDING CAUSES ABORTION VICTORIA SNEGOVSKIKH, ERIC HODGSON, ANNA SFAKIANAKI, EDMUND FUNAI, YUEHONG MA, SETH GULLER, MIZANUR RAHMAN, CATALIN BUHIMSCHI, IRINA BUHIMSCHI, ERROL NORWITZ, Yale University, New Haven, Connecticut OBJECTIVE: Bleeding in the first trimester is associated with spontaneous pregnancy loss, but whether this bleeding causes the abortion or is simply a sign of an already unsuccessful implantation is not clear. Adequate production of hCG by syncytiotrophoblast is critical to the maintenance of early pregnancy by sustaining progesterone production by the corpus luteum. We propose that bleeding may cause abortion by interfering with hCG-progesterone signalling. This study investigates the effect of thrombin on hCG production by syncytiotrophoblast in vitro. STUDY DESIGN: Term placentae were collected from elective cesarean deliveries and cytotrophoblast cells isolated by enzymatic digestion and purified using Percoll gradient. As previously described, cells were cultured in Basal Dulbecco’s medium containing 5% fetal calf serum for 3-4 days at which time syncytiotrophoblast formation was evident. Cells were cultured in fresh serum-free medium and stimulated with or without thrombin (2.5 IU/mL) for 24h. Levels of hCG in conditioned supernatant were measured by specific ELISA and corrected for protein content. Data were analyzed by ANOVA and Chi square tests. RESULTS: Thrombin significantly suppressed hCG levels in conditioned supernatant of cultured syncytiotrophoblast from 40.8 7.5 to 20.7 3.7 mIU/mg of protein per 24h (mean SEM; n 6; p 0.038) (Figure).
Classical and Partial Eta Square in Multifactor ANOVA Designs.

The computation of classical ?72 (reflecting SS(Total) in the denominator) as a measure of strength of association in ANOVA designs from published research reports is often impossible because of insufficient information. Cohen's formula for q2 based on the F-test and relevant degrees of freedom yields classical 7)2 only in one way designs. Use of Cohen's formula in more complex multifactor designs yields a measure of partial 7q2. This paper reviews the distinctions between classical and partial q and derives a formula for use in those complex ANOVA designs in which the investigator desires a measure of classical 7)2 and has access only to the F-tests and relevant degrees of freedom.
Another stride towards knowledge-based machine translation

Building on the well-established premise that reliable machine translation requires a significant degree of text comprehension, this paper presents a recent advance in multi-lingual knowledge-based machine translation (KBMT). Unlike previous approaches, the current method provides for separate syntactic and semantic knowledge sources that are integrated dynamically for parsing and generation. Such a separation enables the system to have syntactic grammars, language specific but domain general, and semantic knowledge bases, domain specific but language general. Subsequently, grammars and domain knowledge are precompiled automatically in any desired combination to produce very efficient and very thorough real-time parsers. A pilot implementation of our KBMT architecture using functional grammars and entity-oriented semantics demonstrates the feasibility of the new approach.1
Salt effects on the denaturation of DNA. V. Preferential interactions of native and denatured calf thymus DNA in Na2SO4 solutions of varying ionic strength.

Precision density measurements were performed at 25°C on Na-DNA-Na2SO4 mixtures in the presence of either 0.005 m cacodylic acid buffer (pH 6.8) or in the presence of 0.1 m NaOH (pH 12.3). From measurements executed under equilibrium dialysis conditions, the so-called “density increments” (∂ρ/∂c2)μ0 for native (pH 6.8), heat-denatured (pH 6.8), and alkali-denatured (pH 12.6) Na-DNA were evaluated as a function of Na2SO4 concentration. (∂ρ/∂c2)μ0 for native DNA was found to decrease almost linearly with ionic strength I1/2 of the supporting electrolyte. The density increment for Na-DNA at pH 12.6, on the other hand, increases in more or less linear fashion with I1/2. (∂ρ/∂c2)μ0 for heat-denatured DNA at pH 6.8 is not affected very much by increasing salt strength. From density measurements performed on the Na-DNA–Na2SO4 mixtures at fixed concentrations of diffusible components, the partial specific volumes ν2° of native (pH 6.8), heat-denatured (pH 6.8), and alkali-denatured (pH 12.6) Na-DNA were determined as a function of Na2SO4 concentration. All ν2° values, irrespective of the secondary structure of the DNA, increase with increasing salt concentration although the increase for heat denatured DNA (pH 6.8) is barely noticeable. ν2° of both native and heat-denatured DNA (pH 6.8) extrapolates to a value of 0.50o ml/g at vanishing salt concentration; ν2° of DNA in 0.1 m NaOH, on the other hand, assumes the value 0.2o ml/g. Distribution coefficients of diffusible components, expressed in terms of preferential water and salt interaction, were evaluated from the (∂ρ/∂c2)μ0 data, solvent densities, and partial specific volumes of all solution components. All interaction parameters depend strongly on salt concentration and on the conformation of DNA. From data collected and from information available in the literature it is concluded that Na2SO4, for instance, displaces water of hydration from native DNA much more readily with increasing salt concentration than does NaCl. The solvation properties of the denatured forms of Na-DNA are rather complex but appear to be in harmony with whatever information can be gathered from the literature.
Protection of B cells against the effect of alloxan.

Abstract Alloxan induces diabetes in laboratory animals through the destruction of the endocrine pancreatic B cells. The mechanism of alloxan toxicity is still obscure. This study was conducted to investigate the effects of Superoxide dismutase (SOD) or reduced nicotinamide adenine dinucleotide (NADPH) treatment on the B cells in isolated rat islets prior to alloxan treatment. Islets were treated with SOD (1000 U) or 0.1 mM NADPH for 10 min followed by alloxan treatment (0.18 mg) for 5 min. Insulin secretion was studied in samples incubated for 60 min in media supplemented with glucose (1.8 mg ml ). Morphological examinations were conducted on fixed samples after the alloxan treatment. SOD significantly protected the islets from the cytotoxic effect of alloxan. Although alloxan decreased insulin secretion to 35% of the control, SOD increased this level to 73% of the control values. NADPH did not provide any protection to the islets. Insulin secretion from islets treated with NADPH and alloxan was not different from that after alloxan treatment alone. Morphological changes were observed in the islets treated with alloxan alone or alloxan in the presence of NADPH. Islets exhibited multiple cellular necrosis, marked degranulation and extensive vesiculation of the endoplasmic reticulum and Golgi complex. Mitochondrial enlargement with disrupted cristae and mitochondrial ruptures were prominent. However, islets treated with SOD and alloxan were similar to the control except for the enlarged mitochondria. The increased insulin secretion from islets treated with SOD and alloxan reinforces the free radical hypothesis of alloxan toxicity. The markedly enlarged mitochondria was one of the targets through which alloxan destroyed the B cells.
Asymmetric Crime Cycles

Recent theoretical models based on dynamic human capital formation, or social influence, suggest an inverse relationship between criminal activity and economic opportunity and between criminal activity and deterrence, but predict an asymmetric response of crime. In this paper we use three different data sets and three different empirical methodologies to document this previously-unnoticed regularity. Using nonparametric methods we show that the behavior of property crime is asymmetric over time, where increases are sharper but decreases are gradual. Using aggregate time-series U.S. data as well as data from New York City we demonstrate that property crime reacts more (less) strongly to increases (decreases) in the unemployment rate, to decreases (increases) in per capita real GDP and to decreases (increases) in the police force. The same result is obtained between unemployment and property crime in annual state-level panel data. These results suggest that it may be cost effective to implement mechanisms to prevent crime commission rates from rising in the first place.
Open source software use in libraries

Purpose – In order to provide a general context for library implementations of open source software (OSS), the purpose of this paper is to discuss the existing presence of OSS in libraries, the functionality and variety of OSS products, and the need for further study into the application of OSS technologies in libraries.Design/methodology/approach – The paper is based on a literature review.Findings – This paper endeavors to provide a broad overview of the deepening relationship between libraries and OSS. Libraries are seeking alternatives to proprietary applications which may require specialized support and/or services. Moreover, OSS and proprietary products have a functional verisimilitude, and, as proprietary applications developers anticipate user needs, so too do OSS contributors.Practical implications – The degree of variance between proprietary and OSS applications, features, support, and compatibility is continually lessening, so libraries are increasingly making use of less costly alternatives to...
Quantum chemical reaction dynamics on a highly parallel supercomputer

In this paper we describe the solution of the quantum mechanical equation for the scattering of an atom by a diatomic molecule on a high-performance distributed-memory parallel supercomputer, using the method of symmetrized hyperspherical coordinates and local hyperspherical surface functions. We first cast the problem in a format whose inherent parallelism can be exploited effectively. We next discuss the practical implementation of the parallel programs that were used to solve the problem. The benchmark results and timing obtained from the Caltech/JPL Mark IIIfp hypercube are competitive with the CRAY X-MP, CRAY 2 and CRAY Y-MP supercomputers. These results demonstrate that such highly parallel architectures permit quantum scattering calculations with high efficiency in parallel fashion and should allow us to study larger, more complicated chemical systems. Future extensions to this approach are discussed.
Simulation of the Fertilization Ca2+ Wave in Xenopus laevis Eggs

Abstract In the preceding paper Fontanilla and Nuccitelli ( Biophysical Journal 75:2079–2087 (1998)) present detailed measurements of the shape and speed of the fertilization Ca 2+ wave in Xenopus laevis eggs. In order to help interpret their results, we develop here a computational technique based on the finite element method that allows us to carry out realistic simulations of the fertilization wave. Our simulations support the hypothesis that the physiological state of the mature egg is bistable , i.e., that its cytoplasm can accommodate two alternative physiological Ca 2+ concentrations: a low concentration characteristic of the prefertilization state and a greatly elevated concentration characteristic of the state following the passage of the wave. We explore this hypothesis by assuming that the bistability is due to the release and re-uptake properties of the endoplasmic reticulum (ER) as determined by inositol trisphosphate (IP 3 ) receptor/Ca 2+ channels and sarcoendoplasmic reticulum calcium ATPase (SERCA) pumps. When combined with buffered diffusion of Ca 2+ in the cytoplasm, our simulations show that inhomogeneities in the Ca 2+ release properties near the plasma membrane are required to explain the temporal and spatial dependences of the shape and speed of these waves. Our results are consistent with an elevated IP 3 concentration near the plasma membrane in the unfertilized egg that is augmented significantly near the site of fertilization. These gradients are essential in determining the concave shape of the Ca 2+ fertilization wave front.
Recent results on lithium ion conductors

Conductivity data for several new lithium ion conductors are presented. Li3N has a very open structure with intersecting tunnels in 2 dimensions. High ionic conductivity has been found at relatively low temperatures. Data indicate that the conductivity can be improved by suitable doping, as well as stoichiometric control. Solid solutions of Li4SiO4 and Li3PO4 have also been investigated. The unit cell of Li4SiO4 contains two SiO−44 tetrahedra linked by 8 Li ions, which are distributed over 18 possible sites. An improvement of the conductivity of about five orders of magnitude at 100 °C has been obtained at 40 mole % Li3PO4. Solid LiAlCl4 has relatively large values of conductivity in the range from room temperature to its melting point at about 146 °C. Upon melting, the ionic conductivity jumps to over 0.1Ω−1 cm−1. Another group of materials are based upon the anti-fluorite structure. Data are presented on Li2S and Li2O. The related compounds Li5AlO4, Li5GaO4, and Li6ZnO4 have a partially occupied cation sublattice. The ionic conductivity of these materials rises very rapidly at about 380°C, reaching very high values over 400°C. The large values of ionic conductivity found in some of these materials may lead to their practical use as solid electrolytes.
Effect of protein adsorption on the transport characteristics of asymmetric ultrafiltration membranes.

The effects of bovine serum albumin adsorption on the transport characteristics of asymmetric poly(ether sulfone) ultrafiltration membranes were determined using polydisperse dextrans with gel permeation chromatography. Actual dextran sieving coefficients were evaluated from observed sieving data for both the clean and preadsorbed membranes using a stagnant film model. The flux dependence of the actual dextran sieving coefficients was used to evaluate the intrinsic membrane hindrance factors for convective (i.e., sieving) and diffusive transport for the different molecular weight dextrans using classical membrane transport theory. Protein adsorption caused a reduction in both dextran sieving and diffusion, with the magnitude of the reduction a function of the dextran molecular weight and pore size. The effects of adsorption on the specific pore area and the membrane porosity were then determined using a recent model for solute transport through asymmetric ultrafiltration membranes. The data indicate that protein adsorption occurs preferentially in the larger membrane pores, causing a greater reduction in solute sieving compared to the membrane hydraulic permeability and porosity than would be predicted on the basis of either a simple pore blockage or pore constriction model.
Multiple effects of an RNA polymerase beta' mutation on in vitro transcription.

S. typhimurium strain BY324 is temperature sensitive due to a mutation (rpo C32) in the gene for the RNA polymerase β′ subunit. Transcription of T7 DNA by RNA polymerase purified from this strain is temperature sensitive in vitro. The enzyme is slightly defective in template binding and RNA chain initiation, but the major defect is in RNA chain elongation. The rate of RNA chain elongation is reduced 4–5 fold relative to wild-type. RNA chain termination does not appear to be affected by the β′ mutation. While the elongation defect is suppressed by glycerol or dimethylsulfoxide, the initiation defect is not. Possible roles for the β′ subunit in enzyme function are discussed in light of these results.
On the peculiarities of monopole and multipole focusing

Abstract Magnetic dipoles can be used to focus electrons and they have very simple focusing properties, both in first order approximation and also in third order, where they have been found to have very small aberrations. These properties have been studied by analytical and digital methods. In view of the simplicity and the fact that dipoles only represent one facet of the whole spectrum of multipoles we have now looked closely at the properties of monopoles on the one hand and quadrupoles on the other. Perhaps it is no surprise, but these two members of the multipole family also display great simplicity and could also be used for focusing electrons.
The influence of metal overlayers on electrochromic behavior of Wo3 films

Metallic overlayers have been deposited on vapor-deposited WO3 to control the kinetics of coloration and bleaching in a WO3-liquid electrolyte electrochromic cell. These over-layers, when porous, have been found to increase the rate of coloration/bleaching and the proton transfer rate at the WO3-electrolyte interface, when appropriate voltages were applied. This effect has been characterized with potentio-static and galvanostatic measurements and compared to the coloration and bleaching of WO3 (without metallic overlayers). Coloration of WO3 films is influenced at short times by resistance and electric field effects, in disagreement with the general assumption of high conductivity in vapor-deposited WO3. The rate of coloration was also influenced by mixed barriers at the WO3-electrolyte interface. The barriers consist of a Schottky barrier at the WO3 surface and a Helm-holtz double layer. The coloration and bleaching mechanisms for WO3 with overlayers have been discussed based upon dif-fusion of electrons through the WO3, WO3-overlayer interface, or the SnO2-WO3 interface, and proton diffusion at the WO3-electrolyte interface. Resistance effects in the WO3 were found to be reduced by the overlayer. Electron injection in WO3 occurred both at the SnO2 and the overlayer inter-faces, thus increasing the rate of proton transfer, and the rate of coloration/bleaching.
Impairments of Control and Compéténce in Epileptic Children and Their Families

Summary: Epilepsy can introduce disturbances within child, parent, and family systems. Epilepsy, as a medical disorder, disrupts the patient's and parents' sense of control and competence. This, in turn, affects the evolving negotiations (the family process) related to the establishment of the child's growing sense of autonomy and competence. Epilepsy's impact on these central family issues, as well as on the child's sense of self, can become the major long-term complication. The medical management of epilepsy must consider how to assist with these issues as part of the overall treatment plan. RESUME L'epilepsie peut etre a l'origine de perturbations dans les systemes relationnels de I'enfant a ses parents et a sa famille. En tant qu'affection medicale, elle rompt le sens du controle, et la competence du malade et de ses parents. Ceci, en retour, retentit sur les negociations en cours de developpement (le processus familial) liees a I'etablissement chez I'enfant du sentiment d'autonomie et de capacitye. L'impact de l'epilepsie sur ces evenements familiaux aussi bien que sur la connaissance de soi meme par I'enfant, peut devenir la complication essentielle a long terme. La conduite medicale face a l'epilepsie doit considerer ces faits et prevoir leur correction dans le cadre du plan therapeutique d'ensemble. RESUMEN La epilepsia puede introducir trastornos en el nino, los padres y los sistemas familiares. La epilepsia, como trastorno medico, altera el sentido de control y competencia del enfermo y de los padres. Esto, a su vez, modifica el proceso familiar que fomenta el es-tablecimiento de creciente sentido de autonomia y competencia del nino. El impacto de la epilepsia en estos asuntos familiares y en el concepto del Yo del nino, puede convertirse en la complicacion mas im-portante a largo plazo. El control medico de la epilepsyia debe considerar estos temas y ofrecer su cor-reccion dentro del plan terapeutico global. ZUSAMMENFASSUNG Die Epilepsie kann Storungen beim Kind hervorru-fen, bei den Eltern und der gesamten Familie. Die Epilepsie als medizinische Erkrankung unterbricht den Sinn fur Kontrolle und Kompetenz beim Patienten und seinen Eltern. Das wiederum beeinflust die Beschaftigung (den Familienprozess) im Hinblick auf die Ver-wirklichung des beim Kindes wachsenden Sinnes fur Autonomic und Kompetenz. Die Beeinflussung dieses zentralen familiaren Anliegens und des Kindes Selbstwertempfinden durch die Epilepsie konnen die hauptsachlichen Langzeitkomplikationon darstellen. Das medizinische Management der Epilepsie mus diese Anliegen bedenken und als Teil des allgemeinen Therapieplanes korrigieren.
Bibliocentrism, Cultural Warrant, and the Ethics of Resource Description: A Case Study

We have not properly studied the uses to which catalogs are put by their users, nor have we attempted until recently to consider empirical evidence in the construction of cataloging rules. The result is an oddly rationalized sort of pragmatism inherent in generations of rules for resource description. This lack of theoretical commitment in resource description has ethical implications for all of information organization because it leads to poorly served users of catalogs. One particularly egregious ethical issue is bibliocentrism. Beghtol challenges us to engage in applications research to affirm a theoretical basis, contrasting cultural warrant with ethical warrant. The importance of cultural warrant in the ethics of knowledge representation follows closely on Hj⊘rland's emphasis on activity-theoretic and domain-specificity. The present study asks whether schemas for resource description restrict access by constraining objectivity. The objective is to discover empirically, via case-study method, some of ...