cssi/SciSciGPT-SciSciNet huggingface dataset:
Adaptive Surrogate Modeling for Efficient Coupling of Musculoskeletal Control and Tissue Deformation Models

Finite element (FE) modeling and multibody dynamics have traditionally been applied separately to the domains of tissue mechanics and musculoskeletal movements, respectively. Simultaneous simulation of both domains is needed when interactions between tissue and movement are of interest, but this has remained largely impractical due to the high computational cost. Here we present a method for the concurrent simulation of tissue and movement, in which state of the art methods are used in each domain, and communication occurs via a surrogate modeling system based on locally weighted regression. The surrogate model only performs FE simulations when regression from previous results is not within a user-specified tolerance. For proof of concept and to illustrate feasibility, the methods were demonstrated on an optimization of jumping movement using a planar musculoskeletal model coupled to a FE model of the foot. To test the relative accuracy of the surrogate model outputs against those of the FE model, a single forward dynamics simulation was performed with FE calls at every integration step and compared with a corresponding simulation with the surrogate model included. Neural excitations obtained from the jump height optimization were used for this purpose and root mean square (RMS) difference between surrogate and FE model outputs (ankle force and moment, peak contact pressure and peak von Mises stress) were calculated. Optimization of the jump height required 1800 iterations of the movement simulation, each requiring thousands of time steps. The surrogate modeling system only used the FE model in 5% of time steps, i.e., a 95% reduction in computation time. Errors introduced by the surrogate model were less than 1 mm in jump height and RMS errors of less than 2 N in ground reaction force, 0.25 Nm in ankle moment, and 10 kPa in peak tissue stress. Adaptive surrogate modeling based on local regression allows efficient concurrent simulations of tissue mechanics and musculoskeletal movement.
Are pharmacokinetic approaches feasible for treatment of cocaine addiction and overdose

“… we discuss the main challenges for developing therapeutic treatment of cocaine addiction and explain why pharmacokinetic approaches, particularly those based on our recently developed efficient cocaine-metabolizing enzymes, are feasible for treatment of cocaine addiction and overdose.”
Trends in Workplace Changes: Follow-Up of Job Analyses

Ergonomic job analysis is considered to be a primary step in preventing work disability related to musculoskeletal problems. There has been little work examining what ergonomic changes are actually occurring after an ergonomic job analysis. This paper looks at what types of workplace changes are being implemented and what if any trends exist in these changes. It was found that in the manufacturing setting, workers were more likely to change jobs and workplace changes occurred with line changes rather than as an accommodation for a particular employee. In the office setting, ad hoc individualized changes to workstations were used in an effort to accommodate workers in their current jobs.
Genetic and environmental underpinnings to age-related ocular diseases

Age-related macular degeneration (AMD), cataract, glaucoma and diabetic retinopathy are common causes of visual loss. Both environmental and genetic factors contribute to the development of these diseases. The modifiable factors related to some of these age-related and visually threatening diseases are smoking, obesity, and dietary factors, and a cardiovascular risk profile. Many common and a few rare genetic factors are associated with AMD. The role of genetic variants for the other diseases are less clear. Interactions between environmental, therapeutic, and genetic factors are being explored. Knowledge of genetic risk and environmental factors, especially for AMD, has grown markedly over the past 2.5 decades and has led to some sight-saving approaches in preventive management.
A versatile, low-cost approach to dynamic light scattering

We describe a method for constructing a fiber-optic-based dynamic light scattering (DLS) instrument from commonly available components, without a need for custom-made parts. Details are provided that allow for academic researchers from diverse backgrounds to build this DLS instrument with minimal effort and at a low cost. This approach, while providing good sensitivity and high accuracy (e.g., measuring the size of latex standards to within 1% relative standard deviation), possesses several advantages not found, in their entirety, in existing DLS instrumentation. It was observed that, even though an arbitrary scattering angle could be selected, aligning this instrument to obtain optimal detection efficiency can be completed in as little as a few minutes. Also, complications associated with light refraction at the sample cell interface are avoided. Small volumes (<10 µL) can be measured, for example, by hanging a solution droplet from the fiber optic probe tips. In addition, use of fiber optic probes allows the beam path length to be as short as 1.6 mm while measuring at 90°, which reduces the likelihood of multiple scattering. With minimal customization, compact submersible probes and a portable battery-operated DLS instrument were made as examples of potential implementation. Finally, this approach is versatile, and can be incorporated into a wide variety of reactors, for in situ characterization, and other instrumentation for hybrid measurements. This type of in situ measurement was conducted after mounting the DLS probes inside a standard three-neck flask. This allowed for direct monitoring of the growth of silica nanoparticles prepared via Stober synthesis.
Variable radix multistable integrated circuits

By means of multistable states in semiconductor junction devices treated in this paper, it is demonstrated both theoretically and experimentally that it is feasible to fabricate discrete and integrated circuits with a variable number of stable states. With negative resistance interactions, additional stable states may be realized, leading to integrated circuits with radices higher than binary. Several independent physical phenomena in unipolar and bipolar semiconductor pn junction devices and integrated structures lead to voltage and current-controlled negative resistance without the use of external feedback. These include avalanche breakdown, quantum mechanical tunneling, and minority carrier storage. Two complementary types of negative resistances may be utilized as a basis for generating multistable energy levels.
General Revenue Sharing

Enacted in 1972, general revenue sharing added a new dimension to the intergovernmental grant system in the United States of America. Unlike traditional categorical grant programs predicated on an externality or some other efficiency-based rationale, revenue sharing addressed issues of vertical and horizontal fiscal imbalances as well as political concerns about the growing influence of the federal bureaucracy in the fiscal affairs of states and localities. Scheduled to terminate at the end of fiscal year 1986, revenue sharing nevertheless remains a viable concept in reckoning the makeup of a well-ordered intergovernmental grant system. It is with an eye toward future deliberations about such a program that this paper is written. The findings from six years of research at the Brookings Institution are drawn upon, and a review is given of the lessons learned about the role of such a program and how the design of any future revenue sharing program might be enhanced, with specific emphasis on greater equity ...
Niemann-Pick-like liver disease and reduced cholesterol esterification in fibroblasts of two male infants

Niemann-Pick disease type C (NPC) presents in about half of the cases in the newborn period with jaundice, hepato-splenomegaly, and a clinical pattern similar to neonatal hepatitis. The definitive diagnosis can in most instances be made by the appropriate biochemical testing of lipoprotein stimulated cholesteryl ester synthesis and cholesterol accumulation in cultured patient fibroblasts. We report two infants who by liver biopsy had classical findings of NPC and a cholesteryl ester synthesis level about 50% of the normal lower limit. On the other hand neither of these patients' fibroblasts showed any evidence of low density lipoprotein-induced cholesterol accumulation, precluding the possibility of a definitive diagnosis. These cases demonstrate the importance of the appropriate biochemical testing before final counseling is carried out. The possibility of our patients representing allelic or nonallelic variants of NPC are discussed.
Potential adverse effects of amphetamine treatment on brain and behavior: a review

Amphetamine stimulants have been used medically since early in the twentieth century, but they have a high abuse potential and can be neurotoxic. Although they have long been used effectively to treat attention deficit hyperactivity disorder (ADHD) in children and adolescents, amphetamines are now being prescribed increasingly as maintenance therapy for ADHD and narcolepsy in adults, considerably extending the period of potential exposure. Effects of prolonged stimulant treatment have not been fully explored, and understanding such effects is a research priority. Because the pharmacokinetics of amphetamines differ between children and adults, reevaluation of the potential for adverse effects of chronic treatment of adults is essential. Despite information on the effects of stimulants in laboratory animals, profound species differences in susceptibility to stimulant-induced neurotoxicity underscore the need for systematic studies of prolonged human exposure. Early amphetamine treatment has been linked to slowing in height and weight growth in some children. Because the number of prescriptions for amphetamines has increased several fold over the past decade, an amphetamine-containing formulation is the most commonly prescribed stimulant in North America, and it is noteworthy that amphetamines are also the most abused prescription medications. Although early treatment does not increase risk for substance abuse, few studies have tracked the compliance and usage profiles of individuals who began amphetamine treatment as adults. Overall, there is concern about risk for slowed growth in young patients who are dosed continuously, and for substance abuse in patients first medicated in late adolescence or adulthood. Although most adult patients also use amphetamines effectively and safely, occasional case reports indicate that prescription use can produce marked psychological adverse events, including stimulant-induced psychosis. Assessments of central toxicity and adverse psychological effects during late adulthood and senescence of adults who receive prolonged courses of amphetamine treatment are warranted. Finally, identification of the biological factors that confer risk and those that offer protection is also needed to better specify the parameters of safe, long-term, therapeutic administration of amphetamines to adults.
Denitrification: Enzyme content and activity in desert soils

Abstract The content of denitrifying enzymes in upland desert soil was strongly associated with indices of N and C availability. Combinations of several predictors could explain 71% of the variance in enzyme content in Chihuahuan desert soils and 87% of the variance in soils from various deserts in the southwestern U.S.A. A significant fraction of the enzyme content in wet desert soil is derived from a persistent pool of enzymes capable of tolerating extended periods of desiccation. The synthesis of new denitrifying enzymes appears to involve a complex interaction between available C, N, and soil moisture. The activity of denitrifying enzymes in desert soil was optimal at a pH of 7.0 and a temperature of 40°C. The Q10 for denitrification was 1.74, and the activation energy was about 41 kJ mol−1. In addition, enzyme activity in freshly wet soil was not limited by NO−3 availability, and only slightly limited by the availability of C. Thus, wet desert soil appears to provide optimal conditions for several variables that can influence denitrification.
The Lunar Gravity Ranging System for the Gravity Recovery and Interior Laboratory (GRAIL) Mission

The Lunar Gravity Ranging System (LGRS) flying on NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission measures fluctuations in the separation between the two GRAIL orbiters with sensitivity below 0.6 microns/Hz1/2. GRAIL adapts the mission design and instrumentation from the Gravity Recovery and Climate Experiment (GRACE) to a make a precise gravitational map of Earth’s Moon. Phase measurements of Ka-band carrier signals transmitted between spacecraft with line-of-sight separations between 50 km to 225 km provide the primary observable. Measurements of time offsets between the orbiters, frequency calibrations, and precise orbit determination provided by the Global Positioning System on GRACE are replaced by an S-band time-transfer cross link and Deep Space Network Doppler tracking of an X-band radioscience beacon and the spacecraft telecommunications link. Lack of an atmosphere at the Moon allows use of a single-frequency link and elimination of the accelerometer compared to the GRACE instrumentation. This paper describes the implementation, testing and performance of the instrument complement flown on the two GRAIL orbiters.
Pattern formation in imaginal discs of Drosophila melanogaster after irradiation of embryos and young larvae.

Abstract Embryos and first instar larvae of Drosophila melanogaster were X-irradiated in order to study pattern formation in discs damaged at early stages. After treatment, appendages were found in which some pattern elements were duplicated and others were absent. In some strains legs were preferentially duplicated, and in others, antennae were preferentially duplicated. Duplicated appendages were mirror images and resulted most frequently when animals were irradiated during late embryonic or early larval stages. Appendages varied from those which showed complete duplication of only the distal parts (claws or aristae), to those which showed duplication of almost the entire appendage. Examination of the cuticular patterns in duplicated mesothoracic legs showed that in legs with complete duplication solely in distal regions, only extreme lateral leg parts were duplicated, and medial leg parts were absent. In legs with duplication extending into proximal regions, much of the lateral side was duplicated, and only extreme medial parts were missing. The situation for partially duplicated antennae was similar. Prothoracic legs were found fused in some X-rayed flies. The cuticular patterns were almost perfect mirror images, although the amount of fusion varied widely between different individuals. Apparently the pattern forming processes in the right and left first leg discs are coordinated in X-rayed animals. The results were consistent with a model embracing a gradient of developmental capacity in the early disc similar to that postulated to exist in the late third instar leg disc. This model is also consistent with results of various surgical experiments reported in the literature. Several predictions of the model are explained including the possible mode of action of a specific class of mutants which may affect pattern formation by altering a morphogenetic gradient.
The effect of country of origin on purchase behaviour: an intercept study

In the present study, consumers were intercepted and surveyed at point of purchase to measure the influence of country of origin on apparel purchase behaviour. In addition, actual consumer awareness of the country of origin of the garment purchased was measured. The findings offer an indication of the relationship between consumer attitudes and purchase behaviour with regard to country of origin. This information may prove useful to retailers involved in or considering involvement in ‘American made’ promotions. Results also offer the residual benefit of gauging the impact of the Crafted With Pride ‘Made in the U.S.A.’ campaign 6 months after the introduction of intense promotion.
Perception of visual speed while moving

During self-motion, the world normally appears stationary. In part, this may be due to reductions in visual motion signals during self-motion. In 8 experiments, the authors used magnitude estimation to characterize changes in visual speed perception as a result of biomechanical self-motion alone (treadmill walking), physical translation alone (passive transport), and both biomechanical self-motion and physical translation together (walking). Their results show that each factor alone produces subtractive reductions in visual speed but that subtraction is greatest with both factors together, approximating the sum of the 2 separately. The similarity of results for biomechanical and passive self-motion support H. B. Barlow's (1990) inhibition theory of sensory correlation as a mechanism for implementing H. Wallach's (1987) compensation for self-motion.
Mapping the receptor-recognition site of human transforming growth factor-α

The receptor-recognition site human transforming growth factor-alpha (TGF alpha), a 50-residue tricyclic peptide with three disulfide bonds, was mapped by a set of 46 peptide analogs consisting of linear, monocyclic, bicyclic, and tricyclic structures representing individual and overlapping subdomains of human TGF alpha. Linear overlapping fragments ranging from 7 to 18 residues and spanning the entire length of TGF alpha as well as monocyclic analogs with one disulfide linkage were found to be inactive in both receptor-binding and mitogenic assays. Bicyclic analogs with two disulfide linkage and representing either the amino or carboxyl two-thirds of TGF alpha showed low activity at 0.1-0.9 mM concentrations. Tricyclic analogs containing all three disulfide linkages but lacking either the amino or carboxyl terminal heptapeptide was, respectively, 3% and 0.1% as active as TGF alpha. These results show that determinants for the receptor binding cannot be represented by a short continuous fragment or a single subdomain, but are located on a discontinuous surface on a folded structure with disulfide restraints. Furthermore, these results when combined with our previous results which shows that the middle subdomain (second disulfide loop) is not involved in the receptor binding suggest that the receptor-binding residues are constituted of three fragments located at the first and third subdomains as well as the external carboxyl peptide.
Readings books and rankings of macromonetary articles, authors and journals

Abstract Articles republished in commercial readings books prove to be a feasible way to rank macromonetary articles, authors, and journals. Rankings are tested by discriminate analysis and by comparison to alternate rankings. Authors' fame is derived from their articles and from the journals in which their articles are published.
Aggravating conditions: cynical hostility and neighborhood ambient stressors.

This study is the first to investigate neighborhood clustering of a personality trait – cynical hostility (a sense of mistrust of others amplified by suspicious antagonism.) Cynical hostility increases physiological reactivity by influencing appraisal and coping when stressful events occur and that has been well established as a predictor of cardiovascular disease, inflammation, and all-cause mortality. The analysis examines the associations of a variety of neighborhood physical and social conditions (especially ambient stressors) with individual cynical hostility, controlling for individual sociodemographics. Data are from the Chicago Community Adult Health Survey, a clustered population-based study of 3105 adults. Variation by neighborhood in cynical hostility is larger than variation of other selected health outcomes, which are commonly studied using ecological methods or for other personality measures. Controlling for neighborhood context reduces the black/white cynical hostility disparity by one-third. A measure of neighborhood ambient stressors (notably noise) significantly predicts cynical hostility, even after individual characteristics are controlled, and the effect size is larger than for other contextual predictors. Health-related psychosocial and personality traits may both cluster in and be influenced by contemporaneous neighborhoods rather than mere exogenous results of genes or early life conditions. Health-relevant psychosocial characteristics may also mediate effects of neighborhood deleterious physical conditions, thereby influencing downstream health outcomes and social disparities therein. Because residential location and neighborhood physical conditions are both modifiable, research on how ambient stressors influence health psychology may be particularly fruitful for health policy and practice.
Religious coping, health, and health service use among bereaved adults.

Objective:This report examined associations between religious coping, health, and health service use among a sample of 265 recently bereaved adults.Method:Participants were interviewed an average o...
Observations on rat kidney multiple cation-activated adenosine triphosphatase fractionated on CM Sephadex C 50☆

Abstract Partial fractionation of Mg ++ + Na + + K + -activated from Mg ++ -activated ATPase activity in deoxycholate extracts of rat kidney subcellular particulate (i.e., the fraction sedimenting between 10,000 and 105,000g) has been accomplished on CM Sephadex C 50 columns. The preparative procedure is reproducible and preparations having activity ratios of 1.44 are strikingly similar to those reported by Skou [ Biochim. Biophys. Acta 58 , 314 (1962)]. In vitro inhibitory effects of aminonucleoside on the partially purified Mg ++ + Na + + K + -activated preparation appear to be completely ascribable to inhibition of the Mg ++ -activated ATPase activity, constituting a major portion of the enzymic activity.
Plants of the northeastern United States that produce cyanogenic compounds

We have surveyed the distribution of plants in the northeastern United States that contain cyanogenic compounds. Approximately 200 species of plants from 45 families are known to contain compounds capable of liberating hydrogen cyanide upon hydrolysis. These are primarily found in the Gramineae, Ranunculaceae and the Rosaceae. The chemical structures compounds of the cyanogens have been studied in only a small number of the species included, and investigation of the biology and chemistry of these plants should prove especially profitable.
Image quality improvement through fusion of hybrid bone- and soft-tissue- texture filtering for 3D cone beam CT extremity imaging system

A flat-panel, detector-based cone beam CT system can provide advantages over a fan beam CT system in terms of 3D isotropic spatial resolution. However, as a result of increased X-ray coverage along the rotation axis, there is also an increase in scatter. This can lead to a decrease in low-contrast resolution as well as the appearance of non-uniform artifacts across the reconstructed image. These effects can be minimized with the use of an anti-scatter grid; however, further software corrections are often desirable. Software scatter correction is generally achieved through the subtraction of an estimate of the scatter distribution from the corresponding original projection data in the linear space. While the non-uniform artifacts effect is generally improved, a side effect of this subtractive process can be an undesirable amplification of the apparent noise, which makes the image quality, in terms of contrast-to-noise ratio (CNR), much worse than the images produced by fan beam CT systems. In this work, a novel modified imaging chain has been proposed to apply separate, non-linear noise-reduction algorithms on bone and soft tissues to improve the CNR for soft tissue as well as to maintain a high spatial resolution for the display of boney structures.
Laser two-photon ionization spectroscopy of molecules in liquids

Abstract A two-photon lonization technique has been developed and applied to determine the photoionization threshold of a molecule in liquid solution. The photoionization of pyrene in n -pentane was studied by monitoring the photocurrent of an≈ 10 −6 M solution as a function of the laser wavelength in the region 360–530 nm, corresponding to two-photon, transition in the region 180–265 nm. The photoionization threshold thus determined is 4.80 ± 0.02 eV. Resonances were observed in the two-photon ionization spectrum which are tentatively ascribed to preionization of one-photon forbidden transitions to states energetically degenerate with the continuum, reached via two-photon absorption.
Water jet cutting of experimental rock discontinuities

Abstract Feasibility of water jet cutting of experimental discontinuities in real, intact rock with reproducible roughness was investigated. Some 60 planar surfaces and undulations were cut in a fine grained sandstone to develop a procedure to control roughness. The final undulating surfaces were natched to form discontinuities with wavelengths of 38 mm with surface roughness similar to No. 100 (sieve size of grains) sandpaper. Cutting of the final surface involves an optimum distance between successive passes of the jet, secondary low pressure washing and an inclined nozzle.
For the public good? The pursuit of private goals through private foundations

This paper illuminates the complex relationships between family and philanthropy within organizational grantmaking, in the process challenging the assumption that nonprofit organizations are primarily motivated by the goal of producing some public good. I propose a theoretically-driven typological classification system that analyzes the extent of a foundation’s professional and family involvement to illuminate the organization’s operative goals (Perrow, 1961). Drawing on five years of participant observation at two large private foundations, as well as interviews with over twenty additional family-funded foundations, I present illustrations of four ideal-type foundations: the tax shelter, the legacy, the family unit, and the professional philanthropist. By highlighting the range of goals driving private foundations, and the multiple structures through which they are organized, I question whether the philanthropic sector is becoming uniformly more professional and isomorphic, as has been argued by others, ...
Mechanisms of accumulation of tyramine, metaraminol, and isoproterenol in isolated chromaffin granules and ghosts.

Abstract The effects of the transmembrane pH gradient (ΔpH) and the transmembrane potential gradient (ΔΨ) on the uptake of several sympathomimetic amines were investigated, using bovine adrenal chromaffin granules isolated in isotonic sucrose. As previously described [R. Johnson and A. Scarpa, J. biol. Chem. 254 , 3750 (1979)], freshly isolated chromaffin granules maintain an intragranular pH of 5.5 as measured by [ 14 C]methylamine distribution and, in the presence of ATP, generate a ΔΨ of 80 mV, positive inside, as measured by [ 14 C]thiocyanate distribution. When tryamine, metaraminol, and isoproterenol (1–50 mM) were added to well-buffered suspensions of granules at pH 7.0, a dose-related alkalinization of the granule interior was observed. Study of the time-resolved influx of the same amines labeled radiochemically (5–21 μM) revealed that all the amines were accumulated against an apparent concentration gradient. However, while accumulation of [ 14 C]serotonin and [ 3 H]isoproterenol was totally inhibited by reserpine, [ 14 C]tryramine accumulation was inhibited by only 60% and [ 14 C]metaraminol uptake was unaffected. The ATP-dependent generation of a ΔΨ produced a stimulation of amine uptake in the order: serotonin > isoproterenol > tyramine; metaraminol accumulation was not enhanced by ATP addition. The relationship between the electrochemical proton gradient (Δ \ gm H + ) and the electrochemical gradient for each of the sympathomimetic amines (Δ \ gm A ) was investigated utilizing chromaffin ghosts devoid of endogenous matrix gradients or components. All amines were accumulated in the presence of ΔpH alone. In the presence of ΔΨ alone, [ 14 serotonin, [ 14 C]tyramine, and [ 3 H]isoproterenol were accumulated, but no [ 3 H]metaraminol uptake was demonstrable. The results indicate that serotonin and isoproterenol accumulated in isolated chromaffin granules and ghosts via a reserpine-sensitive mechanism, driven by the magnitude of the electrochemical proton gradient. Conversely, metaraminol permeated the membrane of the chromaffin granule through the apolar lipid phase and distributed according to the ΔpH alone. Tyramine uptake proceeded by both mechanisms. The implications of the mechanism of accumulation of these potent physiologic and pharmacologie agents for their in vivo action are discussed.
Development of a rapid ribotyping method for Corynebacterium diphtheriae by using PCR single-strand conformation polymorphism: comparison with standard ribotyping

Abstract A rapid and simple ribotyping method for Corynebacterium diphtheriae was developed, based on 16S–23S rRNA spacer region analysis, by using polymerase chain reaction (PCR)–single strand conformation polymorphism (SSCP). All 123 strains tested were PCR positive with primer set rG1 and rL1, and each reaction resulted in only one amplicon of approximately 440 bp in size. When 19 ribotyping type strains and 26 previously ribotyped strains were analyzed by this method, 29 distinct SSCP patterns were identified. Seventeen of 19 established ribotypes could easily be differentiated, and in some cases SSCP ribotyping provided even better resolution than traditional ribotyping. This method provides a rapid, reliable, and reproducible alternative for the traditional ribotyping, which can significantly aid in epidemiological studies, especially where large numbers of strains need to be rapidly analyzed.
Cell biology: mitochondria shape up.

Mitochondria are central to the process of programmed cell death that kills damaged or superfluous cells. Surprisingly, components of the death machinery turn out to be essential for keeping these organelles in shape. How Bcl-2 family members act to regulate programmed cell death (apoptosis) is the subject of intensive research. Karbowski et al. report the discovery of a new and unexpected role for two Bcl-2 family members. Bax and Bak are required in normal cells for the fusion of mitochondria into elongated tubules. This has implications for Bax/Bak function during apoptosis, when they co-localize with mitochondrial fusion mediators Mfn2 and Drp1.
Half-Life of Learning Curves for Information Technology Project Management

Learning curves are used extensively in business, science, technology, engineering, and industry to predict system performance over time. Although most of the early development and applications were in the area of production engineering, contemporary applications can be found in all areas of applications. Information technology project management, in particular, offers a fertile area for the application of learning curves. This paper applies the concept of half-life of learning curves to information technology project management. This is useful for predictive measures of information technology system performance. Half-life is the amount of time it takes for a quantity to diminish to half of its original size through natural processes. The approach of half-life computation provides an additional decision tool for researchers and practitioners in information technology management. Derivation of the half-life equations of learning curves can reveal more about the properties of the various curves with respect to the unique life-cycle property of information technology.
Anthropogenic heat island at Barrow, Alaska, during winter: 2001–2005

[1] The village of Barrow (71°N latitude) is the largest native community in the Arctic, with a population of approximately 4500 people. Situated on the coast of the Arctic Ocean in northernmost Alaska, the area is entirely underlain by permafrost. Although most supplies must be imported, Barrow relies on local natural gas fields to meet all energy requirements for building heat and electrical power generation. This energy eventually dissipates into the atmosphere, and can be detected as a pronounced urban heat island (UHI) in winter. Since 2001, a 150 km 2 area in and around Barrow has been monitored using ∼70 data loggers recording air temperature at hourly intervals. The mean daily temperature of the urban and rural areas is calculated using a representative sample of core sites, and the UHI magnitude (MUHI) is calculated as the difference in the group averages. The MUHI is most pronounced in winter months (December-March), with temperatures in the urban area averaging 2°C warmer than in the surrounding tundra and occasionally exceeding 6°C. The MUHI is maximized under cold and calm conditions, and decreases with wind speed and warmer temperatures. It is strongly and directly correlated to natural gas utilization on a monthly basis. Integrated over the home heating season, there is an 8% reduction in freezing degree days in the village. It is unlikely that anthropogenic heat contributes to the forward shift in the snow meltout date that has been observed near Barrow over the past 60 years.
What lessons need to be learnt from the outbreak of Ash Dieback Disease, Chalara fraxinea in the United Kingdom?

The finding of Ash Dieback (Chalara fraxinea) in the British Isles during 2012 led to an unprecedented level of political and media interest in a tree disease. The background of the disease and actions taken since its discovery is described from scientific, legal, political, administrative, media and industry perspectives. The outcome of the resulting independent expert taskforce is outlined and the lessons already learnt described. Weaknesses in the resulting situation for controlling the spread and impact of plant diseases are explored further in terms of lessons that need to be learnt.
Probing the stability of native and activated forms of α2-macroglobulin

alpha2-Macroglobulin (alpha2M) is a 718 kDa homotetrameric proteinase inhibitor which undergoes a large conformational change upon activation. This conformational change can occur either by proteolytic attack on an approximately 40 amino acid stretch, the bait region, which results in the rupture of the four thioester bonds in alpha2M, or by direct nucleophilic attack on these thioesters by primary amines. Amine activation circumvents both bait region cleavage and protein incorporation, which occurs by proteolytic activation. These different activation methods allow for examination of the roles bait region cleavage and thioester rupture play in alpha2M stability. Differential scanning calorimetry and urea gel electrophoresis demonstrate that both bait region cleavage and covalent incorporation of protein ligands in the thioester pocket play critical roles in the stability of alpha2M complexes.
Protest Reconsidered: Identifying Democratic and Civic Engagement Learning Outcomes

Using a case study approach, the authors examine the democratic and civic engagement learning outcomes of a campus protest. The conceptual framework is built on the ideas outlined in Learning Reconsidered (Keeling 2004) and modeled in its pragmatic follow-up, Learning Reconsidered 2 (Keeling 2006). Results suggest student and campus administrator actions during a campus protest support democratic aims, student development, and digital age democracy. Recommendations for campus educators are included. This study extends previous discussion on activism’s journey from detrimental to developmental (Astin 1999; Chambers & Phelps 1993; Hamrick 1998; Hunter 1988) by mapping the learning environment through the interaction of protestor and university and by incorporating new forms of activism.
Shock Wave Lithotripsy is Not Predictive of Hypertension Among Community Stone Formers at Long-Term Followup

Purpose: Concern exists over the subsequent development of hypertension after shock wave lithotripsy for the treatment of symptomatic urolithiasis. Referral bias and lack of long-term followup have been limitations of prior studies.Materials and Methods: We identified all Olmsted County, Minnesota residents with a diagnosis of urolithiasis from 1985 to 2008. The charts were electronically queried for hypertension and obesity by diagnostic codes, and use of shock wave lithotripsy by surgical codes. All patients first diagnosed with hypertension before or up to 90 days after the first documented kidney stone were considered to have prevalent hypertension and were excluded from analysis. Cox proportional hazards models were used to assess the association of shock wave lithotripsy with a subsequent diagnosis of hypertension.Results: We identified 6,077 patients with incident urolithiasis with more than 90 days of followup. We excluded 1,295 (21.3%) members of the population for prevalent hypertension leaving ...
Synthesis and characterization of solution-processable core-cyanated perylene-3,4;9,10-bis(dicarboximide) derivatives.

Core-cyanated perylene-3,4;9,10-bis(carboxyimide) derivatives N-functionalized with tethered anthracenes (PDI3A-CN2, PDI4A-CN2) and the corresponding solution-processable cycloadduct precursors (PD...
Relations between acoustic cavitation and skin resistance during intermediate- and high-frequency sonophoresis.

Abstract Enhanced skin permeability is known to be achieved during sonophoresis due to ultrasound-induced cavitation. However, the mechanistic role of cavitation during sonophoresis has been extensively investigated only for low-frequency (LFS, 1 MHz). The electrical resistance of skin, a surrogate measure of the permeability of skin to a variety of compounds, was measured to quantify the reduction and subsequent recovery of the skin barrier during and after exposure to pulsed (1 second pulse, 20% duty cycle) 0.41 and 2.0 MHz ultrasound over a range of acoustic powers (0–21.7 W) for 30 min. During IFS, significant skin resistance reductions and acoustic emissions from cavitation were measured exclusively when cavitation was isolated outside of the skin. Time-dependent skin resistance reductions measured during IFS correlated significantly with subharmonic and broadband emission levels. During HFS, significant skin resistance reductions were accompanied by significant acoustic emissions from cavitation measured during trials that isolated cavitation activity either outside of skin or within skin. Time-dependent skin resistance reductions measured during HFS correlated significantly greater with subharmonic than with broadband emission levels. The reduction of the skin barrier due to sonophoresis was reversible in all trials; however, effects incurred during IFS recovered more slowly and persisted over a longer period of time than HFS. These results quantitatively demonstrate the significance of cavitation during sonophoresis and suggest that the mechanisms and post-treatment longevity of permeability enhancement due to IFS and HFS treatments are different.
Compass and Straightedge in the Poincaré Disk

(2001). Compass and Straightedge in the Poincare Disk. The American Mathematical Monthly: Vol. 108, No. 1, pp. 38-49.
Evidence for the involvement of catecholamines in the 2-DG-induced immunomodulatory effects in spleen.

The role of catecholamines in immune changes associated with the metabolic stress of 2-deoxy-D-glucose (2-DG) was examined in this study. Male Lewis rats were pretreated with the nonselective beta-adrenergic receptor antagonist nadolol (0-0.5 mg/kg) and then received either a saline or 2-DG (500 mg/kg) injection. Nadolol attenuated the 2-DG-induced suppression of splenic T-cell mitogenic response and interferon-gamma production and increased nitric oxide production by macrophages in a dose-dependent manner. Conversely, nadolol did not attenuate the 2-DG-induced changes in immune parameters in peripheral blood leukocytes. These results suggest that the peripheral release of catecholamines is responsible for 2-DG-induced splenic immune alterations, whereas the peripheral release of catecholamine is not responsible for 2-DG-induced blood immune alterations. Furthermore, the neuroendocrine mechanisms responsible for splenic immune changes induced by the metabolic stress of 2-DG administration were the same as those involved in immune changes induced by physical and psychological stress. Thus, this study suggests that common neuroendocrine pathways exist for several types of stress-induced immunomodulations.
Stimulation of Food Species Growth by Limpet Mucus

The trails of mucus secreted by certain species of intertidal limpets serve as adhesive traps for the microalgae that are their primary food resource. In addition, the mucus trails of two solitary homing limpets, Lottia gigantea and Collisella scabra, stimulate growth of the microalgae that the limpets consume. In contrast, the trails of an aggregating limpet, Collisella digitalis, do not stimulate microalgal growth. These results and their possible ecological significance are interpreted in light of the differences in the behavioral repertoires of the three limpet species.
Mixtec Migrants in Mexico City: A Case Study of Urbanization

This article examines the formation of a village association among a group of Mixtec migrants from the village of San Bartolo Soyaltepec living in Mexico City. Five aspects are considered in some detail: (1) the formation of the village association in the urban environment; (2) the degree to which the village association resembles the system of government in the rural village; (3) the nature of the interaction between the village association and the government in the village; (4) the impact of the village association on the social organization of the community; and finally, (5) the role which the village association performs as a cultural institution mediating the process of urbanization for both the migrants and the society of Soyaltepec. It was found that the formation of the village association is of critical importance in the adaptation to urbanization which ultimately involves changes in the social organization of the rural community as well.
Eocene–Oligocene global climate and sea-level changes: St. Stephens Quarry, Alabama

We integrate upper Eocene–lower Oligocene lithostratigraphic, magnetostratigraphic, biostratigraphic, stable isotopic, benthic foraminiferal faunal, downhole log, and sequence stratigraphic studies from the Alabama St. Stephens Quarry (SSQ) core hole, linking global ice volume, sea level, and temperature changes through the greenhouse to icehouse transition of the Cenozoic. We show that the SSQ succession is dissected by hiatuses associated with sequence boundaries. Three previously reported sequence boundaries are well dated here: North Twistwood Creek–Cocoa (35.4–35.9 Ma), Mint Spring– Red Bluff (33.0 Ma), and Bucatunna-Chickasawhay (the mid-Oligocene fall, ca. 30.2 Ma). In addition, we document three previously undetected or controversial sequences: midPachuta (33.9–35.0 Ma), Shubuta-Bumpnose (lowermost Oligocene, ca. 33.6 Ma), and Byram-Glendon (30.5–31.7 Ma). An ~0.9‰ δ 18 O increase in the SSQ core hole is correlated to the global earliest Oligocene (Oi1) event using magnetobiostratigraphy; this increase is associated with the ShubutaBumpnose contact, an erosional surface, and a biofacies shift in the core hole, providing a fi rst-order correlation between ice growth and a sequence boundary that indicates a sea-level fall. The δ 18 O increase is associated with a eustatic fall of ~55 m, indicating that ~0.4‰ of the increase at Oi1 time was due to temperature. Maximum δ 18 O values of Oi1 occur above the sequence boundary, requiring that deposition resumed during the lowest eustatic lowstand. A precursor δ 18 O increase of 0.5‰ (33.8 Ma, mid-chron C13r) at SSQ correlates with a 0.5‰ increase in the deep Pacifi c Ocean; the lack of evidence for a sea-level change with the precursor suggests that this was primarily a cooling event, not an ice-volume event. Eocene–Oligocene shelf water temperatures of ~17–19 °C at SSQ are similar to modern values for 100 m water depth in this region. Our study establishes the relationships among ice volume, δ 18 O, and sequences: a latest Eocene cooling event was followed by an earliest Oligocene ice volume and cooling event that lowered sea level and formed a sequence boundary during the early stages of eustatic fall.
The occurrence of peripheral deposits of lipid in atheromatous plaques of arteries

Abstract Localized collections of fat-laden phagocytes occur with sufficient frequency at the edges of old intimal plaques to indicate that these areas are particularly susceptible to new lipid deposits. It is suggested that the fibrous replacement of such peripherally situated masses of lipid is the chief method by which old plaques may continue to undergo progressive enlargement. Analysis of the main characteristics of the marginal lipid deposits favors the view that their accumulation depends upon the anchoring and immobilizing effects of the previously formed fibrous plaque rather than upon any special, localized increase of permeability to lipid. It is further hypothesized that these zones of lipid are formed by a gradual movement and collection of diffusely dispersed lipid displaced from the intimal tissue adjoining the plaques under the impetus of arterial pulsations and that such periatheromatous masses, by reason of their bulk and relatively protected situation, are more resistant to resorption than scattered streaks and patches of lipid.
Commentary: Memristor and memristive switch mechanism

Many nanostructures exhibit electrically stimulated change of resistance and have been proposed as the basis for non-volatile random access memories (NVRAM), but progress toward implementation has been delayed by difﬁculties in understanding and controlling the resistive switching phenomena [1]. To design a device that can be reliably used for information processing, one needs (i) a mathematically consistent theory for modeling the circuit component, and (ii) knowledge of the underlying operating principles so that one might improve a device by ﬁne tuning parameters such as doping and geometrical proﬁle. Recent breakthrough occurred at Hewlett-Packard Laboratories has been receiving increasing attention in both fundamental researches and commercial applications. In May 2008, HP scientists announced the discovery of the missing circuit element memristor, acronym for memory resistor. The memristor concept gives a simple explanation for many puzzling voltage-current characteristics in nanoscale electronics [2]. Researchers also clariﬁed coupled electron-ion dynamics responsible for memristive switch [3]. With the reported advance, HP is promising prototypes of ultradense memory chips in 2009.
Finding Optimal Refueling Policies in Transportation Networks

We study the combinatorial properties of optimal refueling policies, which specify the transportation paths and the refueling operations along the paths to minimize the total transportation costs between vertices. The insight into the structure of optimal refueling policies leads to an elegant reduction of the problem of finding optimal refueling policies into the classical shortest path problem, which ends in simple and more efficient algorithms for finding optimal refueling policies.