cssi/SciSciGPT-SciSciNet huggingface dataset:
The Dark Side of Social Media: What Makes Some Users More Vulnerable Than Others?

Existing studies have not reached a consensus with regard to how social media may positively or negatively affect users' well-being. In this study, we endeavor to contribute towards HCI/CSCW knowledge on this open space and offer more empirical evidence. In doing so, we conducted 10 semi-structured in-depth interviews to explore the downsides of social media. We present four themes in social media use that adversely affect users' well-being emerging in participants' self-reports, namely, social comparison, fear of missing out, political discussions, and cyberbullying. Furthermore, we discuss two potential dynamics through which people consider their social media use negative to their well-being: 1) self-oriented internalization where users perceive the social media experience differently (negative or neutral) based on their personality traits; and 2) content-oriented internalization where users perceive the experience negative regardless of their personality traits. We argue that identifying these two dynamics of internalization helps understand the complex relationships between social media use and user well-being, which can then inform the future design of social media systems to remedy these adverse social and psychological impacts.
Introduction, in CRITICAL CONCEPTS IN INTELLECTUAL PROPERTY LAW: COPYRIGHT

The two-volume set entitled Critical Concepts in Intellectual Property Law: Copyright brings together a thought-provoking collection of landmark and recent scholarship on copyright. Section 1 of Volume I focuses on the history of copyright, with Tyler Ochoa and Mark Rose providing an example of the prevailing interpretation of the history and articles by Thomas Nachbar and by William Treanor and Paul Schwartz offering fresh takes on the early English and American experiences. Section 2 focuses on copyright’s philosophical foundations, framed by the work of Justin Hughes and followed by revisionist perspectives on Lockean and Hegelian theory offered by Seana Shiffrin and Jeanne Schroeder. Section 3 focuses on democratic theories, presented through the work of Neil Netanel and a critique of Netanel authored by Shyamkrishna Balganesh.Volume II examines the economics of copyright. Section 1 of Volume 2 covers public goods economics, monopoly theory, and price discrimination, introducing the concepts through the work of Terry Fisher before turning to Michael Meurer’s and Christopher Yoo’s critiques and extensions of the conventional wisdom. Section 2 focuses on transaction cost economics, beginning with Wendy Gordon’s classic article on fair use, followed by Robert Merges’s celebrated study of how holders of intellectual property rights can contract into liability rules, Abraham Bell and Gideon Parchomovsky’s analysis of the forces that can drive a legal regime from open access property to private property and vice versa, and Clarisa Long’s discussion of the way that intellectual property can minimize information costs. Section 3 explores the political economy of copyright, including Jessica Litman’s analysis of the political dynamics surrounding the Copyright Act of 1976, Thomas Nachbar’s review of Noah Webster’s campaign to establish copyright in the colonies and the early United States, and Robert Merges’s survey considering theories of political economy that go beyond simple rent seeking.
A Remedy Foreclosed? Mortgage Foreclosure and the Fair Debt Collection Practices Act

During the Global Financial Crisis, millions of homeowners received foreclosure notices. Many of these notices were sent by attorneys, and informed consumers of an impending mortgage foreclosure. Courts are split on whether foreclosures must conform with the Fair Debt Collection Practices Act (FDCPA). In order to be subject to the FDCPA, an entity must meet the statutory definition of “debt collector.” Courts struggle with whether foreclosure attorneys fall under this definition. This Note examines this conflict, and suggests a fact-sensitive framework for evaluating whether foreclosure attorneys are debt collectors.
Characteristics of proposed and enacted state tobacco control legislation in the United States, 2010-2015

This study documents all tobacco control proposals (bills) introduced in the United States into all 50 state legislatures from the start of 2010 through 2015 and assesses associations between tobacco-related strategies and tobacco product types with enactment of the bills into law. In total, members of state legislatures introduced 2801 tobacco control bills, and state legislatures enacted 17.4%. Bills most introduced addressed clean air (n = 696) and tax or price bills (n = 582), yet both had lower likelihood of enactment (each OR, 0.51; 95% CI 0.38–0.69) compared to bills on any other tobacco control strategy. Legislators introduced only 147 product manufacturing bills, but these had the highest odds of enactment (OR, 3.70, 95% CI 2.52–5.44) compared to any other intended strategy, followed by tax evasion (OR, 3.08; 95% CI 2.33–4.08) and retailer licensing or location (OR, 1.73; 95 CI 1.24–2.41). Compared to other products, bills regulating e-cigarettes had the highest enactment rate (21.2%). Despite introduction of many bills promoting traditional, evidence-based tobacco control strategies, these had less likelihood of enactment than others.
Interval-valued Markov Chain Abstraction of Stochastic Systems using Barrier Functions

This paper presents a stochastic barrier function-based abstraction technique for discrete-time stochastic systems. Recent works have shown the potential of Interval-valued Markov Chain abstractions for conducting efficient verification of continuous-state, discrete-time stochastic systems against complex objectives, as well as efficient synthesis for finite-mode switched stochastic systems. Such Markovian abstractions allow for a range of transition probabilities between its states. In this work, we address the problem of constructing Interval-valued Markov Chain abstractions for polynomial systems using stochastic barrier functions. Stochastic barrier functions serve as Lyapunov-like probabilistic certificates of forward set invariance. Specifically, given a finite partition of the system's domain, we show that bounds on the probability of transition between any two elements of the partition are found by generating stochastic barrier functions via optimization procedures in the form of Sum-of-Squares programs. We present an algorithm for solving these optimization problems whose implementation is demonstrated in a verification and a synthesis case study.
The association of neighborhood social vulnerability with surgical textbook outcomes among patients undergoing hepatopancreatic surgery

Abstract Background Previous studies have largely examined social determinants of health relative to individual surgery quality metrics. We sought to characterize possible differences in “textbook outcome,” a composite measure of quality, relative to social vulnerability index. Methods The Medicare Standard Analytical Files from 2013 to 2017 were used to identify beneficiaries who underwent hepatopancreatic surgery. Individuals were stratified into 3 groups dependent on their social vulnerability (low, average, high). Textbook outcome was defined as absence of postoperative surgical complications, prolonged length of stay, 90-day readmission, and 90-day mortality. Results Among 32,142 patients who underwent hepatopancreatic surgery, 18,841 (58.6%) patients underwent a pancreatectomy, whereas 13,301 (41.4%) underwent a hepatectomy. The overall incidence of textbook outcome after hepatopancreatic surgery was 51.2% (n = 16,445). Patients with a low social vulnerability index who underwent pancreatic resection more often achieved a textbook outcome versus patients who had an average or high social vulnerability index (low social vulnerability index: 48.3% vs average social vulnerability index: 46.5% vs high social vulnerability index: 44.9%; P = .004). The odds of obtaining a textbook outcome after pancreatic surgery was inversely associated with degree of vulnerability (low social vulnerability index, referent: average social vulnerability index: odds ratio 0.94, 95% confidence interval 0.87–1.00 vs high social vulnerability index: odds ratio 0.89, 95% confidence interval 0.82–0.97). Similarly, social vulnerability index was independently associated with textbook outcome after hepatic resection. Likewise, there were increased risks and incidence of various postoperative surgical outcomes, including 90-day mortality and complications as the social vulnerability index increased. Conclusion Only one-half (51.2%) of Medicare beneficiaries achieved the composite quality textbook outcome metric. Social vulnerability was associated with lower attainment of textbook outcome and an increased risk of adverse postoperative surgical outcomes after hepatopancreatic surgery.
The parable of the railway agent: stories of progress and winter legumes in the twentieth-century South

This essay examines the abbreviated fiction-writing career of an unlikely author, Central of Georgia Railway agricultural agent Jesse Frisbie Jackson. In the process, the essay explores the central...
Minimizing hydrogen vacancies to enable highly efficient hybrid perovskites

Defect-induced non-radiative losses are currently limiting the performance of hybrid perovskite devices. Experimental reports have indicated the existence of point defects that act as detrimental non-radiative recombination centres under iodine-poor synthesis conditions. However, the microscopic nature of these defects is still unknown. Here we demonstrate that hydrogen vacancies can be present in high densities under iodine-poor conditions in the prototypical hybrid perovskite MAPbI3 (MA = CH3NH3). They act as very efficient non-radiative recombination centres with an exceptionally high carrier capture coefficient of 10−4 cm3 s−1. By contrast, the hydrogen vacancies in FAPbI3 [FA = CH(NH2)2] are much more difficult to form and have a capture coefficient that is three orders of magnitude lower. Our study unveils the critical but overlooked role of hydrogen vacancies in hybrid perovskites and rationalizes why FA is essential for realizing high efficiency in hybrid perovskite solar cells. Minimizing the incorporation of hydrogen vacancies is key to enabling the best performance of hybrid perovskites. First-principles calculations reveal that hydrogen vacancies induce non-radiative losses in methylammonium lead iodide perovskites synthesized under iodine-poor conditions, whereas they are less detrimental in formamidinium-based hybrid perovskites.
Heme Binding to HupZ with a C-Terminal Tag from Group A Streptococcus

HupZ is an expected heme degrading enzyme in the heme acquisition and utilization pathway in Group A Streptococcus. The isolated HupZ protein containing a C-terminal V5-His6 tag exhibits a weak heme degradation activity. Here, we revisited and characterized the HupZ-V5-His6 protein via biochemical, mutagenesis, protein quaternary structure, UV-vis, EPR, and resonance Raman spectroscopies. The results show that the ferric heme-protein complex did not display an expected ferric EPR signal and that heme binding to HupZ triggered the formation of higher oligomeric states. We found that heme binding to HupZ was an O2-dependent process. The single histidine residue in the HupZ sequence, His111, did not bind to the ferric heme, nor was it involved with the weak heme-degradation activity. Our results do not favor the heme oxygenase assignment because of the slow binding of heme and the newly discovered association of the weak heme degradation activity with the His6-tag. Altogether, the data suggest that the protein binds heme by its His6-tag, resulting in a heme-induced higher-order oligomeric structure and heme stacking. This work emphasizes the importance of considering exogenous tags when interpreting experimental observations during the study of heme utilization proteins.
Calibrated Resampling for Imbalanced and Long-Tails in Deep Learning.

Long-tailed distributions and class imbalance are problems of significant importance in applied deep learning where trained models are exploited for decision support and decision automation in critical areas such as health and medicine, transportation and finance. The challenge of learning deep models from such data remains high, and the state-of-the-art solutions are typically data dependent and primarily focused on images. Important real-world problems, however, are much more diverse thus necessitating a general solution that can be applied to diverse data types. In this paper, we propose ReMix, a training technique that seamlessly leverages batch resampling, instance mixing and soft-labels to efficiently enable the induction of robust deep models from imbalanced and long-tailed datasets. Our results show that fully connected neural networks and Convolutional Neural Networks (CNNs) trained with ReMix generally outperform the alternatives according to the g-mean and are better calibrated according to the balanced Brier score.
Professionalism, Organizationalism and Sur-moralism: Three ethical systems for physicians.

Over the last 50 years, the term professionalism has undergone a widespread expansion in its use and a semantic shift in its meaning. As a result, it is at risk of losing its descriptive and analytical value and becoming instead simply an empty evaluative label, a fate described by C. S. Lewis as 'verbicide' (Lewis 1967). This article attempts to rescue professionalism from this fate by down-sizing its extension and reassigning some of its work to two other ethical domains, introduced as the neologisms organizationalism and sur-moralism. Professionalism is defined as a morality based in system of obligations that are assumed by physicians over the course of their professional training and which primarily refer to two groups: patients and colleagues, including trainees. Organizationalism is also a morality, but the obligations are owed to the employing organization and on different grounds. A third ethical domain, here called sur-moralism, comprises actions that are not based in obligations. They are discretionary and potentially meritorious; they cannot be required by the profession or organization. This article presents a conceptual model of the three ethical domains and the shifting borders between them. One practical benefit of this typology is that physicians can more accurately understand the nature and sources of obligations that they are asked to accept, and when necessary prioritize them. Another is that physicians will be able to describe the potential tension between the three domains and understand how and why the borders between them can move. Both should help physicians to be more ethically oriented to their work settings.
Switching behavior of solutions of ordinary differential equations with abs-factorable right-hand sides

Abstract We consider nonsmooth dynamic systems that are formulated as the unique solutions of ordinary differential equations (ODEs) with right-hand side functions that are finite compositions of analytic functions and absolute-value functions. Various non-Zenoness results are obtained for such solutions: in particular, any absolute-value function in the ODE right-hand side can only switch between its two linear pieces finitely many times on any finite duration, even when a discontinuous control input is included. These results are extended to obtain numerically verifiable necessary conditions for the emergence of “valley-tracing modes”, in which the argument of an absolute-value function is identically zero for a nonzero duration. Such valley-tracing modes can create theoretical and numerical complications during sensitivity analysis or optimization. We show that any valley-tracing mode must begin either at the initial time, or when another absolute-value function switches between its two linear pieces.
Review of Policies Toward the Acceleration of the Adoption of Renewable Energy Technologies

This chapter reviews energy policy supporting diffusion of renewable energy (RE) and describes different types of available RE. The increased level of carbon dioxide is the main cause of the “Global Warming Effect.” One suggested solution to global warming is to replace the current energy technologies with alternatives that have similar or even better performance, but do not emit greenhouse gases (GHGs). Beside environmental concerns, energy availability concerns and political pressure have prompted governments to look for alternative energy resources that can minimize the undesirable effects for current energy systems. Shifting away from the conventional fuel resources and increasing the percentage of generated electricity from renewable resources is an opportunity to guarantee lower (CO2) emissions and to create better economic opportunities for the United States. RE resources offer a good alternative for the current fossil fuel system with its minimal impact on the environment and unlimited availability. Even with the fact that a diversity of renewable energy resources available in the United States and the development of the technologies themselves are more mature, the use of such resources is still very limited in the United States, but as the fossil fuel system is deteriorating with price increase and supply scarcity the transition to a new era of renewable energy is inevitable (Energy Policy 31:353–367, 2003). Policy can play an important role in promoting the penetration of renewable energies (Energy Policy 39:4726–4741, 2011). This chapter discusses the available policies that can promote RE adoption and deployment as well as the available technologies and literature assessing that adoption.
Saturn's E Ring in the Red Spectral Region

Observations of the 1966 edge-on presentation of Saturn's E-ring in the red spectral region are presented. Techniques to suppress the glare from the planet are described. The E-ring profile does not exhibit a maximum near the orbit of Enceladus in 1966. Historical comments concerning the E-ring are included to illustrate that important planetary work can be done by ground-based observations.
A Review of Unsteady Turbulent Boundary-Layer Experiments

The essential results of a comprehensive review of existing unsteady turbulent boundary-layer experiments are presented. Different types of unsteady flow facilities are described, and the related unsteady turbulent boundary- layer experiments are cataloged and discussed. The measurements that have been obtained in the various experiments are described, and a complete list of experimental results is presented. All the experiments that measured instantaneous values of velocity, turbulence intensity, or turbulent shear stress are identified, and the availability of digital data is indicated. The results of the experiments are analyzed, and several significant trends are identified. An assessment of the available data is presented, delineating gaps in the existing data, and indicating where new or extended information is needed. Guidelines for future experiments are presented.
High-resolution spectroscopy of the 88Sr+ single ion optical frequency standard

The present decade has seen great advances in optical frequency standards following the development of femtosecond laser frequency combs. With this technology, combined with a stable and narrow probe laser source (50-100 Hz linewidth), we made a systematic study of the 5 s 2 S 1/2 -4 d 2 D 5/2 (S-D) transition frequency of the 88 Sr + ion as a function of the quantization axis in the trap. This study revealed the presence of systematic shifts caused by residual micromotion in our rf Paul trap and led to an evaluation of those shifts. Also, a method was developed based on the measurement of the Zeeman spectrum of the clock transition to cancel the electric quadrupole shift caused by patch potentials on the trap electrodes. From these results, we also determined the absolute frequency of the S-D clock transition frequency at 674 nm with a fractional frequency uncertainty of 3.4 × 10 -14 . We have since made improvements to our probe laser system and have observed 5 Hz Fourier transform limited linewidths on a Zeeman component of the S-D transition of the 88 Sr + ion. To observe such a narrow transition it is essential to have a known and well behaved drift of the laser frequency during the few minutes it takes to measure the ion resonance using the quantum jump signal. Our approach to minimize the drift rate and its sensitivity to temperature fluctuations has been to stabilize the cavity at the temperature where its coefficient of thermal expansion is zero. We will present an overview of our recent progress made on the frequency standard based on the laser-cooled and trapped single ion of 88 Sr + .
Protein supplements and exercise

Active persons ingest protein supplements primarily to promote muscle strength, function, and possibly size. Currently, it is not possible to form a consensus position regarding the benefit of protein or amino acid supplements in exercise training. Determination of whether supplements are beneficial has been hampered by the failure to select appropriate endpoints for evaluation of a positive effect. Furthermore, studies focused at a more basic level have failed to agree on the response of protein metabolism to exercise. An additional complication of dietary studies that is not often taken into account is amount of energy intake. Because of these and other complications, studies at the whole body level have not yielded a clear picture of the need for, or response to, dietary protein or amino acid supplements. Consequently, it is necessary to examine this issue at the tissue level. In untrained subjects, both muscle protein breakdown and synthesis are increased in response to exercise. Amino acid intake further stimulates muscle protein synthesis after exercise as a consequence of stimulating amino acid transport into the intramuscular compartment. The stimulatory effect of amino acids after exercise is greater than the effect of amino acids on muscle protein synthesis when given at rest. These data suggest that not only may the exact composition and amount of an amino acid supplement be important, but the timing of ingestion of the supplement in relation to the exercise must be considered in designing future studies to evaluate the efficacy of amino acid supplements.
Early Determinants of Non-Exclusive Breastfeeding among Guatemalan Infants

Ethnographic and observational studies suggest that during the perinatal period, physiological, psychosocial, and cultural factors influence initiation and maintenance of breastfeeding and patterns of feeding nonhuman milk substances (Perez-Escamilla et al. 1996, 1998; Scott & Binns 1999; Chapman & Perez-Escamilla 1999). Public health nutritionists need to understand the etiology of non-exclusive breastfeeding in the first 6 months of life because of the mismatch between actual and recommended breastfeeding practices (Lutter 2000; Seilen 2001). Studies have found that delayed lactogenesis stage II (LS-II) can be assessed by milk volume, human milk biomarkers, and maternal perception and recall of onset of lactation and if not resolved is a cause of actual and perceived difficulties with breastfeeding in the first days postpartum, persistent insufficient milk volume, early introduction of infant formula or other nonhuman milk substances, and reduced breastfeeding duration (Chapman & Perez-Escamilla 1999, 2000a; Dewey 2001). To date, few studies have examined the causes or effects of delayed LS-II in rural populations in developing countries.
Modified Coulomb interaction in a pseudo one-dimensional metal

Abstract In a pseudo one-dimensional metal we find that inter channel Coulomb interaction is almost always important. This leads to the result that the Fourier transform of the Coulomb interaction is approximately the same as in three dimensions, φ q ≈ 4πe 2 q 2 a 2 L , and quite unlike a strictly one-dimensional result. The interplay between one- and three-dimensional effects is further elucidated in a brief discussion of the dielectric function of a pseudo one-dimensional metal.
Avian Response to Frost-Damaged Aspen in Northern Utah

ABSTRACT . In early May 2007, northern Utah mountains experienced a period of prolonged warmer-than-normal temperatures, followed by a frost that killed or damaged much of the first-flush quaking aspen (Populus tremuloides) foliage. We assessed the effects of this transitory disturbance on the aspen bird species assemblage by comparing breeding bird survey data collected in the Bear River Mountain Range, Utah, USA, in 2005 and 2006 (predisturbance) to data from 2007 (postdisturbance). Whereas bird total abundance, species richness, and species diversity did not differ significantly among years, there were significant year-by—frost damage severity interactions, with plots with low levels of frost damage having significantly higher total abundance, richness, and diversity. Based on these results, we concluded that (1) at the landscape scale, the postdisturbance avian species assemblage was essentially identical to the predisturbance assemblage both in terms of number of individuals and species, and (2) ther...
Scientists and Swindlers: Consulting on Coal and Oil in America, 1820–1890

Pennsylvania has recently become engaged in unearthing the natural gas deposits long known to be lurking far beneath the surface in that state's Appalachian basin region known as the Marcellus shal...
Transient nature of rhizosphere carbon elucidated by supercritical freon-22 extraction and 13 C NMR analysis

Abstract The region immediately adjacent to established roots of mature trees has been termed the “reoccurring rhizosphere” and it has been hypothesized that organic matter input from fine root turnover, root exudates and sloughing may result in a build up of the soil carbon in this region. The “reoccurring rhizosphere” for first-, second- and third-order roots of select loblolly pines (Pinus taeda L.) were examined on sandy, loamy sand and sandy loam soils. A significant carbon build up next to the root orders was confirmed for the sandy and loamy sand soils. The carbon build up was substantial (55% increase) next to the first-order roots of the sandy soil. However, the sandy loam soil did not display a significant amount of carbon build up next to the root orders. Extraction of the soil samples with supercritical freon-22 showed that the additional carbon in the “reoccurring rhizosphere” was highly soluble. Approximately 60% of the total soil carbon was extracted from the sandy and loamy sand soils, while approximately 40% was extracted from the sandy loam soil. A qualitative comparison of the extracts by liquid state 13 C nuclear magnetic resonance showed that the “reoccurring rhizosphere” region had a higher relative proportion of labile materials (i.e. carbohydrates, proteins, etc.) than the bulk soil. This information coupled with the high solubility in supercritical freon-22 suggests that the carbon build up in the “reoccurring rhizosphere” region of loblolly pines may be transient in nature.
Urban and industrial air pollution in Houston, Texas —I. Hydrocarbons

Abstract During the Summer of 1973 and 1974, ambient air samples were collected at sites in downtown Houston and the near-by Pasadena and La Porte industrial complex to determine the hydrocarbon composition in relation to emission sources. Ground level samples were collected at one hour intervals and analyzed for C1–C6 hydrocarbons without delay in order to avoid any sample deterioration due to storage. In addition at selected times, helicopters were used to sample at 500 and 1000 ft elevation. Meteorological conditions were recorded and their effects on the hydrocarbon composition evaluated. As expected, the hydrocarbon spectrum of downtown Houston air resembled that of auto exhaust and showed a strong dependence on traffic density and local meteorology. The hydrocarbon composition at the industrial sites largely depended on the wind direction and magnitude, i.e. local point sources. This study has also indicated removal of some of the hydrocarbons by the photochemical reactions.
Newell and Simon's Logic Theorist: Historical Background and Impact on Cognitive Modeling

Fifty years ago, Newell and Simon (1956) invented a “thinking machine” called the Logic Theorist. The Logic Theorist was a computer program that could prove theorems in symbolic logic from Whitehea...
Annular pancreas in adults: imaging features in seven patients.

Background: Annular pancreas is a rare congenital abnormality that may be associated with variable degrees of duodenal obstruction. This diagnosis is often overlooked in adult patients who present with symptoms suggestive of duodenal obstruction. Imaging evaluation aids in establishing the diagnosis. We evaluated the imaging findings in seven adult patients with known annular pancreas. Methods: Seven adult patients with abdominal symptoms had evaluation with one or more of the following imaging studies: upper gastrointestinal (UGI) series, computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP). All patients underwent subsequent laparotomy as a part of routine care. Surgical and imaging findings were correlated in each patient. Results: UGI series is suitable for demonstrating different degrees of duodenal narrowing at the level of pancreatic annulus. Contrast-enhanced abdominal CT is useful in visualizing directly the complete or partial annular pancreatic tissue. ERCP is particularly useful in visualizing the annulus duct coursing around the duodenum. Conclusions: Imaging plays a pivotal role in the diagnosis of annular pancreas in adult patients avoiding surgery for confirmation with its associated cost and risks.
Ecclesiological reflections on Kathryn Tanner's: Jesus, humanity and the trinity

This review explores the incipient ecclesiology of Kathryn Tanner's brief systematic theology, Jesus, Humanity and the Trinity. Gift is the central concept around which Tanner's articulation of the divine life and the incarnation revolves. The lack of ecclesial definition in Jesus, Humanity and the Trinity creates tension between Tanner's theology of gift and her insistence elsewhere on the church as a ‘genuine community of argument’. Her brief appeal to a ‘community of mutual fulfillment’ needs more elaboration to head off worrisome interpretations of her vision of divine and human economies. An ecclesiological extrapolation from Tanner's Christology in Jesus, Humanity and the Trinity suggests that the church needs to be at once a community in which God's gifts are received and shared and a community of argument in which problems and shortcomings in the church's life can be faced and negotiated.
Representation of Mechanical Behavior in the Presence of Changing Internal Structure

The paper is concerned with the representation of the relationship that exists, for a given material and temperature and for small deformations, between histories of applied stress and the observed strain and the accompanying changes in internal structure of the material. Emphasis is given to creep damage in metals as a vehicle for illustration of the main ideas introduced in the paper. In particular, the role played by irreducible even rank tensors in the representation of internal structure is discussed and clarified. The restrictions placed by thermodynamics on constitutive equations are considered and the use of potentials in these equations is examined and criticized.
Linear feedback shift registers as vector quantisation codebooks

Linear feedback shift registers with fixed initial conditions can be used as codebooks for vector quantisation data compression methods, avoiding the need to store codebooks at the encoder and decoder. Suboptimal search procedures can be used to effectively search the codebook space with lower complexity, with only modest coding performance penalties.
Joint Segregation of Malate Dehydrogenase and Diaphorase Loci in Brown Trout (Salmo trutta)

Abstract Results of genetic analyses are described for the duplicated liver and neural malate dehydrogenase loci (MDH-1 and MDH-2), including a null allele at MDH-1. Analysis of diaphorase (DIA) variation supports a model of a single locus coding for monomeric DIA in brown trout. Random joint segregation was observed between MDH-1 and MDH-2 and between DIA and MDH-2 in testcross progeny of heterozygous males and females.
A generalization of a theorem of Ky Fan on simplicial maps

A combinatorial result is proved which generalizes a theorem of Ky Fan on simplicial maps from a pseudomanifold. A version of the Kronecker Theorem in Topology is also derived as a special case.
Differential effects of testosterone plus dihydrotestosterone on male courtship of castrated newts, Taricha granulosa

Abstract Sexually responsive Taricha granulosa males were castrated and implanted with testosterone (T), dihydrotestosterone (DHT), T plus DHT, or no steroid. The incidence of sexual behavior was highest in castrates implanted with T plus DHT. Newts implanted with T or DHT exhibited sexual behavior more frequently than did the untreated castrates, which exhibited none during the last 5 days of testing. A second experiment was conducted using sexually unresponsive males. The occurrence of sexual behavior remained low in castrates implanted with T plus DHT, untreated castrates, and intact control males. These results support the hypothesis that for this species of amphibian the presence of adequate levels of testicular androgen is a necessary, but not sufficient, condition for the manifestation of sexual behavior; the appearance of these behaviors requires, in addition, the presence of some nontesticular hormone.
Combination therapy of urogenital embryonal rhabdomyosarcoma in children

Twenty-seven children with embryonal rhabdomyosarcoma of the urogenital tract were treated between 1960-1971. A review of their courses reveals that early stage of the disease at the time of diagnosis and multidisciplinary therapy —surgery, radiotherapy, and multiple drug therapy—offer the best chance for prolonged survival and cure. Seventeen (63%) of the 27 children are living and have been free of the tumor for 18 months-10 years.
Oxygen as a factor in eukaryote evolution: some effects of low levels of oxygen on Saccharomyces cerevisiae.

A comparative study of the effects of varying levels of oxygen on some of the metabolic functions of the primitive eukaryote, Saccharomyces cerevisiae, has shown that these cells are responsive to very low levels of oxygen: the level of palmitoyl-Co A desaturase was greatly enhanced by only 0.03 vol % oxygen. Similarly, an acetyl-CoA synthetase associated predominantly with anaerobic growth was stimulated by as little as 0.1% oxygen, while an isoenzyme correlated with aerobic growth was maximally active at much higher oxygen levels (greater than 1%). Closely following this latter pattern were three mitochondrial enzymes that attained maximal activity only under atmospheric levels of oxygen.
Investigation of secondary science teachers' beliefs and practices after authentic inquiry‐based experiences

This study continues research previously conducted by a nine-university collaborative, the Salish I Research Project, by exploring science teachers' beliefs and practices with regard to inquiry-oriented instruction. In this study, we analyzed the relationship among secondary science teachers' preparation, their beliefs, and their classroom practices after completion of a course designed to provide authentic inquiry experiences. From Teacher Pedagogical Philosophy Interview data and Secondary Science Teacher Analysis Matrix observational data, we analyzed links between the teachers' conveyed beliefs and observed practice regarding the teachers' actions (TA) and students' actions (SA). Also presented is a listing of teachers' perceived influences from university preparation course work. Results indicated that 7 of the 8 teachers professed a belief in teacher-centered or conceptual style with regard to TA and SA. The observational results indicated that 7 of the 8 teachers displayed a teacher-centered or conceptual style with regard to TA and SA. Inconsistencies between interview and observational data were unexpected, as half of the teachers professed slightly greater teacher-centered styles with regard to TA than what they actually practiced in their classrooms. All teachers reported that an inquiry-based science course was valuable. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 938–962, 2006
Simultaneous clustering and embedding for multiple intimate mixtures

Classical unmixing algorithms focus primarily on scenarios with a single mixture. These techniques are easily extensible in the case of images with multiple discrete mixtures (i.e. no shared endmembers). Unmixing in scenarios with multiple mixtures with shared or common endmembers is significantly harder. Manifold clustering and embedding seem tailor-made for such a scenario, but generally these algorithms focus on intersecting manifolds (i.e. manifolds that pass through each other) rather than adjoining manifolds (i.e. manifolds that share a boundary) as is the case with mixtures. In this paper we propose a NNMF based technique for simultaneous manifold clustering and embedding of adjoining manifolds. The algorithm is based on including a clustering term in the objective for finding an appropriate reconstruction matrix. The performance of the new algorithm is tested on a toy dataset made of a couple of simulated manifolds which share a boundary and a simulated dataset made up of two ternary Hapke mixtures with two shared endmembers. The algorithm shows improvements on the state-of-the-art manifold clustering algorithms in terms of both clustering and embedding.
Linear Independence of Time-Frequency Translates in \mathbb {R}^d

We establish the linear independence of time-frequency translates for functions \(f\) on \(\mathbb {R}^d\) having one-sided decay \(\lim _{x \in H,\ |x|\rightarrow \infty } |f(x)| e^{c|x| \log |x|} = 0\) for all \(c>0\), which do not vanish on an affine half-space \(H \subset \mathbb {R}^d\).
X-ray metal film filters at cryogenic temperatures

Thin aluminum foil filters have been evaluated at cryogenic temperatures. The results of the test program, including cold cycling and vibration testing, indicate that these filters are fully successful at cryogenic temperatures and can provide the high x-ray transmittance and high background rejection required for the blocking filters which are being developed for the X-Ray Spectrometer, one of the focal plane instruments on the Advanced X-Ray Astrophysics Facility.
Strain bursts in pure copper subjected to various forms of static and cyclic loading at ambient temperature

Abstract The phenomenon of strain bursts has been discovered in pure polycrystalline copper subjected to cyclic or static creep, cyclic incremental tension and cyclic tension-compression. In cyclic creep, bursts appear over the stress range 0.5–0.8 of the ultimate tensile strength. The threshold stress for cyclic creep is much lower than this, however, and the lower limit for the appearance of bursts is believed to be dictated by the sensitivity of the apparatus used to detect them. Bursts can be produced in exaggerated form by slight increments of stress when the material has reached a saturated state. The bursts were usually observed to be more pronounced the higher the stress level. The mechanism of the strain bursts is discussed. They are shown not to be caused by dynamic strain aging (due to an impurity, say, such as oxygen). Their mechanism is also different in detail from that of the bursts observed by Neumann because the dislocation structures are different. We conclude that they are caused purely by dislocation locking and the subsequent sudden collapse of the locking mechanism.
The Pediatrician as Mot her

Sir .—I am a pediatrician. A brief 9 months ago I had an enlightening experience, which led to a "fellowship" in general pediatrics. I became a mother. This much-undervalued specialty can be as difficult, as stressful, and as utterly enjoyable as the neonatal intensive care unit, the emergency department, the office, or the ward. I do take a break from mothering two short afternoons a week when I "go to work" at a clinic and leave my little one with a housekeeper. I also work at home in the evening after he's asleep. My child eats well, sleeps well, and is growing well. My career is, at best, at a standstill, and our finances are in ruins. My colleagues are sure I've gone nuts because I decided to raise my child rather than hire someone (like a nanny) for the job. My female colleagues who don't have children sometimes say
Dynamic NMR Study of Ligand Exchange Reactions in U(VI)−Phosphonic Acid Systems

The rates of hydrogen ion exchange on phosphonic acid ligands and that of phosphonate ligand exchange on selected uranyl-phosphonate complexes have been investigated by dynamic NMR spectroscopy. The spin-spin relaxation time (ln(1/T{sub 2})) for H{sup +} exchange on the fee ligands exhibits a parabolic dependence on reciprocal temperature (1/T (K{sup {minus}1})). The empirical fit parameters are correlated with the activation parameters ({Delta}H{sup *}, {Delta}S{sup *}, {Delta}C{sub p}{sup *}) by adapting the statistical mechanical framework developed by Braibanti et al. to the Eyring activated complex theory. The correlation of the apparent activation enthalpy with temperature indicates that 6--11 water molecules participate in the transition from reactants to activated complex for ligand proton exchange reactions, depending on the ligand. Mechanistic details of ligand exchange reactions of phosphonic acid complexants onto the corresponding uranium(VI) complexes are not fully developed, but the negative values for {Delta}S{sup *} imply increased order in the transition to the activated complex. Though {Delta}H{sup *} for ligand exchange covers a range of 15 kJ/mol, the free energy of activation ({Delta}G{sup *}) is nearly constant for the series of ligands, implying substantial entropy compensation in the activation process. Application of the Marcus relationship defines a correlation between {Delta}G{sup *} andmore » the thermodynamic stability ({Delta}G{degree}) for the 1:2 uranyl complexes with methanediphosphonic acid and 1-hydroxyethane-1,1-diphosphonic acid.« less
The wave of the future

Since technology tends to move in unexpected directions, visions of the future are often more about today than tomorrow.
Quantitative explanation of strong multi-frequency intensity scintillation spectra using refractive scattering

Abstract Under evening equatorial conditions, strong intensity spectra observed simultaneously on transmissions through the ionospheric F-region at 40, 140 and 360 MHz from a stationary satellite are explained quantitatively in terms of refractive scattering using the approach of Booker and Majidiahi (1981). Use is made of an outer scale (wavelength/2gp) of 50 km, an inner scale of 5 m and an integrated mean square fluctuation of ionization density [ ∝ (ΔN) 2 dz ] of 1028 m−5. The spectral index required to fit the observations is 3, and no major departure from this value is permissible either way. This produces the correct spectral behavior at high fluctuation frequencies and the correct ratios of the upper roll-off frequencies at the three wave frequencies. The RMS fluctuation of phase is about 130 rad at 360 MHz, 340 rad at 140 MHz and 1200 rad at 40 MHz. At 40MHz the scale of the intensity fluctuation at ground level is about 10m, and this is caused by refractive scattering in the ionosphere at scales of the order of the outer scale; removal of practically all fluctuations in the ionosphere at scales below the Fresnel scale leaves the fine structure of the intensity spectrum at ground level virtually unaffected.
Analysis of power supply induced jitter in actively de-skewed multi-core systems

This paper studies multi-core clock distribution using active deskewing methods. We propose an efficient methodology that uses Verilog-A to model PLLs, clock trees and power supply variation in multi-core designs. Using the methodology, we compare four different de-skewing topologies (region-based, linear, ring, and a tree) for nominal performance and robustness to power supply variation. We conclude that under nominal conditions, the ring and line topologies are better with a large number of cores, but, when power supply is considered, the region topology is best.
Reducing capacity of terrestrial humic acids

The role of terrestrial humic substances as electron shuttles in bioreduction processes has gained broad acceptance as recognition has grown that the ability to transfer electrons to humic materials is distributed widely among microorganisms in nature. A fundamental property of humic substances pertinent to their mediation of reductive transformations is the maximum moles of electron charge they can transfer to an added oxidant, a parameter for which the name Reducing Capacity has been suggested. A number of different operational definitions of this important parameter have appeared in the literature recently, leading to conflicting terminology that has not heretofore been rationalized. In this paper, we present a consistent set of independent definitions of Reducing Capacity and develop laboratory methodologies for applying them, illustrating our concepts and methods with representative International Humic Substances Society (IHSS) humic acids that have been widely studied in connection with electron shuttling. Our principal results are: (1) non-negligible Reducing Capacity for humic acid (HA) maintained under oxic conditions, indicating that important reductant functional groups persist in humic substances, and (2) Reducing Capacity of chemically-reduced HA equal, within experimental precision, to that for microbially-reduced HA, indicating that chemical reduction can be used as a convenient laboratory method to assess the capacity of HA to be reduced by microorganisms. Our results also demonstrate that complexed Fe contributes negligibly to the Reducing Capacity of HA. We further illustrate our proposed definitions by applying them to interpret some published field data on the Reducing Capacity profile of HA measured in a freshwater lake sediment exhibiting a pronounced redox zonation.
Suggested role of the Golgi apparatus and endoplasmic reticulum for crucial sites of hepatitis C virus replication in human lymphoblastoid cells infected in vitro.

Iacovacci et al. [(1997a) Research in Virology 148:147-151] described that the euploid diploid cells, of the normal human bone marrow-derived lymphoblastoid B-cell line TO.FE., are susceptible to hepatitis C virus (HCV) infection and support long term virus production. Transmission electron microscopy described some steps of HCV replication cycle in this in vitro infected cellular system [Serafino et al. (1997) Research in Virology 148:153-159]. In the present study, in order to identify the intracellular sites involved in HCV replication, the ultrastructural changes associated with infection in TO.FE. cells were correlated with the subcellular localisation of structural and nonstructural viral proteins. Transmission electron microscopy and confocal microscopy data indicate that these viral proteins appeared located in the Golgi apparatus and endoplasmic reticulum, suggesting an active involvement of these compartments in viral assembly and morphogenesis. Furthermore, transmission and scanning electron microscopic observations on cultures infected chronically support the hypothesis that these cellular compartments may serve as starting sites of the morphological changes associated to viral infection and replication, leading to cell-cell fusion, syncytia formation, and finally lysis of infected cells and virus release.