cssi/SciSciGPT-SciSciNet huggingface dataset:
Chinese tourism growth to U.S. national parks and gateway communities: a case study in West Yellowstone, Montana.

Chinese outbound tourism is one of the fastest growing industries worldwide, and with this growth, there has been a surge in international tourism to national parks. For example, 40% of Chinese travelers visited a national park during their U.S. travels (Office of Travel and Tourism Industries [OTTI], 2016). As one of the most popular national parks in the world, Yellowstone National Park (YELL) has swelled in Chinese visitation (Resource Systems Group [RSG], 2017). Despite positive economic aspects of increased tourism, parks and communities are faced with challenges that can impact management and the tourists’ experience. There is extremely limited research on Chinese tourism to U.S. national parks, and this study addresses these gaps through a case study in West Yellowstone, the most popular gateway community of YELL. Through over 50 interviews with Chinese tourists, tour operators, and local business owners, specifically, we aim to gain a greater understanding of: 1) Chinese travel trends and motivations for visiting national parks, 2) Chinese tourists’ perceptions of park resources, 3) Chinese tourists’ modes for communication and information exchange, and 4) perceptions and strategies implemented by businesses in gateway communities to adapt to Chinese tourism.Major findings of the study include that Chinese tourists at YELL primarily obtain their information from friends, family, and Chinese websites with limited tourists visiting or using the National Park Service (NPS) YELL website. Our findings suggest that national park and gateway community communications on social media apps such as WeChat are a major area for growth and opportunity. Finally, the gateway community of West Yellowstone is experiencing changes due to an influx of Chinese-owned businesses and tourists, and offer insight for how to adapt to change. This study addresses a largely understudied topic despite the growing trends of Chinese tourists to national parks and protected areas globally. The study’s findings will be of interest to other parks and protected areas around the world that are experiencing or are anticipating Chinese tourism growth, and offers implications for Chinese tourism communication and marketing outside the national park setting. Finally, our exploratory study presents an opportunity for researchers and practitioners to further study Chinese tourism to national parks and gateway communities in diverse settings, which can lead to comparability of findings and also support dialogue around tourism planning, marketing, communication for protected areas and their gateway communities. Subscribe to JPRA
Independent Pressure and Flow Rate Control Enabled by Hydraulic Free Piston Engine

Fluid power consumes a significant portion of energy annually with relatively low efficiency, especially for mobile applications. This is mainly due to the current architecture where an internal combustion engine (ICE) driven hydraulic pump is used to supply fluid to various driving and working circuits. This architecture as well as the response time limitation of the ICE and the hydraulic pump cause significant fluid throttling loss and low-efficiency engine operation at part load conditions. As a novel alternative, the hydraulic free piston engine (HFPE) eliminates the mechanical crankshaft and integrates the ICE and the hydraulic pump into one unit. Due to its ultimate freedom on the piston motion and reduced inertia, the HFPE has the potential to produce variable fluid power in an efficient manner with fast response time. In this paper, such potential is investigated. The working principle of a prototype HFPE is described and a comprehensive HFPE model is developed. A novel control method, namely the independent pressure and flow rate control (IPFC), is proposed to regulate the HFPE's output flow rate at any given load pressure and realize throttleless fluid control. The effectiveness of the method is demonstrated through simulations, which show the capability of the control method in providing different output flow rates at variable load pressures within tens of milliseconds. Additionally, a detailed analysis of the HFPE efficiency, in terms of thermal efficiency of the engine and mechanical efficiency of the pump, has been conducted under different working conditions. The results show that with the IPFC, the HFPE is an efficient and flexible mobile fluid power source.
Efficient Electrochemical Deprotection of Carboxylic and Amino Acids from Their 2-(Hydroxymethyl)-1,3-dithiane (Dim) Esters

Carboxylic acids and amino acids are electrochemically deprotected from their 2-(hydroxymethyl)-1,3-dithiane (Dim) esters.
A rat model for assessing the long-term safety and performance of peripheral nerve electrode arrays.

Abstract Background High-resolution peripheral nerve interfaces (PNIs) can provide amputees with intuitive motor control and sensory feedback. Current PNIs are limited by early device failure and suboptimal long-term stability. The present study aims to incorporate functional assessment into an in vivo test platform to assess the long-term safety and performance of PNIs for recording and stimulation. New methods Utah electrode arrays (EA) were implanted in the rat sciatic nerve along with electromyography wires in the gastrocnemius and tibialis anterior. Cranial EEG screws were implanted in the somatosensory cortex for 12 weeks. Spontaneous neural activity was recorded using the implanted EA and stimulation-induced activity was monitored throughout the experiment. The impedance of each electrode was measured, and nerve function tests were conducted throughout the EA lifetime. Post-hoc safety assessments included scanning electron microscopy (SEM) of the EA and nerve histomorphometric analysis. Results EA recordings were stable, and stimulation with EA elicited somatosensory evoked potentials and muscle contractions. Motor and sensory function tests indicated minimal deficits. Histomorphometric analysis indicated changes in nerve microstructure. SEM indicated EA-tip fracture, while lead wire breakage primarily caused device failure. Comparison with existing methods We improved our prior platform with the addition of functional assessments of sensory pathways, a robust EMG array design to increase device longevity, and quantitative analysis of nerve microstructure. Conclusion We present a test platform for long-term assessment of peripheral nerve interfaces for stimulation and recording. Using this platform, we demonstrate recording and stimulation with minimal impact on nerve function, while EA lead wire breakage and tip fracture could limit long-term device use.
Celebrating Reinforced Soil Structures

The first use of High Density Polyethylene (HDPE) polymeric geogrid reinforcement in civil engineering was to reinforce and construct a 2.5 m high temporary reinforced soil wall at Newmarket/Silkstone colliery in West Yorkshire, UK in 1980, just 2 years after the first polymeric geogrid was invented by Dr Mercer in 1978 in Blackburn, UK. HDPE geogrid Reinforced Soil Retaining Wall (RSRW) Systems have since been widely used around the world forming various geometries, reaching unprecedented retaining heights in excess of 60 m and serving various functions from supporting open air golf courses to airport runways.
Examining the Utility of a Novel Neurologic Test in Patients With Obstructive Sleep Apnea: A Pilot Study.

Purpose: To test the association between participant King-Devick Test (KDT) times and obstructive sleep apnea (OSA) severity and evaluate for improvement after continuous positive airway pressure (...
Interferon-beta (IFNb) Reprograms Pathogenic Lung Dendritic Cells in Human Chronic Lung Allograft Dysfunction (CLAD)

Purpose Dendritic cells (DC) are central to the induction and maintenance of T regulatory cells (T-regs) and lung allograft tolerance. We previously identified a TNFR2+ subset of CD11b+CD24+CD64- lung resident DC (TNFR2+DC) in mice. TNFR2+DC is responsible for the Th2 response and inflammation in mice. Interestingly, TNFR2+DC is plastic and intra-nasal administration of IFNβ reprograms TNFR2+DC to generate T-regs in the lung and reversed lung inflammation in mice. We hypothesize that a healthy human donor lung has a phenotypically similar tolerogenic TNFR2+DC, which becomes inflammatory in CLAD, and treatment with IFNβ reprogram TNFR2+DC to a tolerogenic phenotype. Methods Single-cell suspensions prepared from the healthy human donor lungs during the lobar transplantation, and CLAD tissue from patients undergoing re-transplantation at the University of Florida. Identification of TNFR2+DC populations and the response to IFNβ (200ng IFNβ, R&D systems INC) were investigated with fluorescent-dye-conjugated antibodies and flow cytometry analysis. Results We identified the TNFR2+DC population in both healthy donor lungs and CLAD lungs (n=4/group) (Figure 1A). The healthy lung TNFR2+DC constitutively express TGFβ1, IDO-1, and Arg-1, which are similar to tolerogenic DC in mouse lungs. Conversely, TNFR2+DC from CLAD patients had decreased TGFβ1, Arg-1, PD-L1, but increased IL-4 and IL-23 expression (Figure 1B). Lastly, treatment with IFNβ increased TGFβ1, Arg1, and decreased IL-4 expression in CLAD TNFR2+DC (n=2). Thus, similar to mice, treatment with IFNβ reprograms pathogenic TNFR2+DC in CLAD to phenotypically tolerogenic DC (Figure 1C). Conclusion This is the first report of TNFR2+DC, a subset of lung resident DC, in healthy human lung and CLAD tissue. TNFR2+DC is plastic, and IFNβ reprograms TNFR2+DC from a pathogenic to a tolerogenic phenotype. Further studies are required to assess the utility of TNFR2+DC plasticity for achieving lung allograft tolerance.
Virus infection associated acute encephalopathy

Virus infection associated acute encephalopathy is not rare, with high mortality and morbidity in serious cases.This article focused on the causes, pathological mechanism, risk factors and treatment of virus infection associated acute encephalopathy. Key words: Virus infection; Encephalopathy; Children,
Genitourinary manifestations of hereditary cancer predisposition syndromes in children

Several hereditary cancer predisposition syndromes are associated with genitourinary (GU) manifestations in children. The GU manifestation may be the first symptom of a more global syndrome to arise, which places the pediatric urologist in a unique position to impact the health of the child. Some GU manifestations are pathognomonic for a particular hereditary cancer predisposition syndrome, which can prompt genetic testing and enhanced surveillance for other features of the condition. In other cases, knowledge of an underlying hereditary cancer predisposition syndrome alters treatment decisions. This review focuses on hereditary cancer predisposition syndromes that impact the GU tract and are likely to be seen by a pediatric urologist.
Diagnosing Mechanisms of Ocean Carbon Export in a Satellite-Based Food Web Model

The net primary productivity (NPP) of marine phytoplankton is ~ 50 Pg C yr-1, and roughly 10-20% of this NPP is exported out of the surface ocean as sinking particulate organic carbon (POC). Numerous mechanisms are hypothesized to control POC export out of the surface ocean but the relative importance of the various mechanisms remains poorly quantified on global scales. Here, we use a previously published satellite-based mechanistic model of POC export to examine the effects on global POC export of size-specific physical aggregation, size-specific and temperature-dependent zooplankton fecal pellet production, and size-specific and temperature-dependent non-grazing phytoplankton mortality. We test these mechanisms in different model configurations to determine if these processes improve the ability of the model to match POC export observations, and to assess the role of each process in controlling global POC export. We find that all model configurations predict that over 60% of the global POC export is from small zooplankton fecal pellets. All model configurations predict similar total POC export, and we find only small differences in the magnitude, timing, and geographical variations of total POC export. However, the fraction of total POC export due to sinking phytoplankton aggregates, and that due to the fecal pellets of large zooplankton, vary by more than a factor of two across the different model configurations. The POC export in all models is most sensitive to parameters controlling zooplankton fecal fluxes and non-grazing phytoplankton mortality. We compared zooplankton grazing rates predicted by the models to results of experimental data, and found that some models match the experimental grazing rates better than others, although data uncertainties remain large. More field measurements of bulk ecosystem rates (i.e., phytoplankton aggregation and zooplankton grazing), as well as explicit determinations of of the proportion of fecal matter to phytoplankton aggregation, will help to better constrain mechanistic models of global POC export.
Plant-Based Meats, Human Health, and Climate Change

There is wide scale concern about the effects of red meat on human health and climate change. Plant-based meat alternatives, designed to mimic the sensory experience and nutritional value of red meat, have recently been introduced into consumer markets. Plant-based meats are marketed under the premise of environmental and human health benefits and are aimed to appeal a broad consumer base. Meat production is critiqued for its overuse of water supplies, landscape degradation, and greenhouse gas emissions—depending on production practices, environmental footprints may be lower with plant-based meat alternatives. Life-cycle analyses suggests that the novel plant-based meat alternatives have an environmental footprint that may be lower than beef finished in feedlots, but higher than beef raised on well-managed pastures. In this review, we discuss the nutritional and ecological impacts of eating plant-based meat alternatives versus animal meats. Most humans fall on a spectrum of omnivory: they satisfy some nutrient requirements better from plant foods, while needs for other nutrients are met more readily from animal foods. Animal foods also facilitate the uptake of several plant nutrients (zinc and iron), while plant nutrients can offer protection against potentially harmful compounds in cooked meat. Plant and animal foods operate in symbiotic ways to improve human health. The mimicking of animal foods using isolated plant proteins, fats, vitamins, and minerals likely underestimates the true nutritional complexity of whole foods in their natural state, which contain hundreds of nutrients that impact human health. Novel plant-based meat alternatives should arguably be treated as meat alternatives in terms of sensory experience, but perhaps not as true meat replacements in terms of nutrition. If consumers wish to replace some of their meat with plant-based alternatives in the diet (a “flexitarian approach”) this is unlikely to negatively impact their overall nutrient status, but this also depends on what other foods are in their diet and the life stage of the individual.
Magnetic transitions and structural characteristics of Mn-doped α-Fe2O3/silica nanocomposites

Hematite (α-Fe2O3) has become popular these days for their photocatalytic activities of water splitting. Metal-doped hematite materials are interesting as well for the bandgap engineering and for resolving fast charge–hole recombination. In this study, magnetism and ionic behaviors of rare manganese-doped α-Fe2O3/silica nanocomposites are investigated. These nanocomposites are prepared by the impregnation method with a mixture of metal halides, followed by rapid heating (30 °C/min) under air condition. When the molar ratio between FeCl3·6H2O and MnCl2·4H2O is 2.97, wasp-waisted hysteresis and ferromagnetism with the Curie temperatures of 56.1 and 58.0 K are observed for the nanocomposites annealed at 600 °C for the duration of 3 and 7 h, respectively, while dominant spin glass states are observed for the nanocomposites annealed at 500 °C. In x-ray diffraction patterns, mixed phases of α-Fe2O3 are identified, whereas crystalline metallic Mn or Mn oxides are hardly found. Electron energy-loss spectroscopy study indicates that Mn2+ is severely oxidized, and with this oxidation of Mn2+, Si becomes more metallic. When the molar ratio between Fe and Mn halides is 7.32, magnetism is affected by a small amount of γ-Fe2O3, and spin glass states and the competition between ferromagnetism and antiferromagnetism are observed in the long temperature range.
From single flies to many genes: Using Drosophila to explore the genetics of psychostimulant consumption.

In our everyday life, we are often exposed to addictive agents like pain killers, tobacco, alcohol, even food, sex, or video games. Although the majority of people will not develop an addiction upon contact with those agents, a part of the population will. What determines whether a person is going to develop a pathological pattern upon exposure to an addictive agent? Family studies reveal a genetic influence in drug responses and addiction, and addictions are actually one of the most hereditable psychiatric disorders (1). Despite this, it has been challenging to identify specific genes that make an individual more susceptible to becoming addicted in human studies. The reasons for this include the need for large sample sizes due to the polygenic nature of addiction, where many genes have small effects. Furthermore, addiction is influenced by many environmental factors, such as socioeconomic status, childhood trauma, the availability/prevalence of the drug itself, and the cost (in time and money) to perform such large studies in the first place. Many of these limitations can be avoided by the use of model organisms, especially ones that allow for high-throughput assays like Drosophila melanogaster . This is what a recent PNAS paper by Baker et al. (2) tackles by assaying 18,000 single flies for their consumption of sucrose with, or without, the addition of the psychostimulants cocaine and methamphetamine (Fig. 1). Fig. 1. Strategy used to identify SNPs involved in Drosophila cocaine and methamphetamine consumption. An advanced intercross population (AIP) containing 18,000 flies was subjected to single-fly feeding behavior of food containing only sucrose or sucrose supplemented with either cocaine or methamphetamine. From all the flies, the top 10% high consumers were selected and sequenced. The comparison of the top consumers sequence with that of a control population through extreme quantitative trait locus analysis (xQTL) allowed … [↵][1]1To whom correspondence may be addressed. Email: iris.titos{at}utah.edu or adrian.rothenfluh{at}hsc.utah.edu. [1]: #xref-corresp-1-1
Experimental evolution of insect resistance to two pesticide classes reveals mechanistic diversity and context-dependent fitness costs

Does rapid adaptation to stressors evolve through similar underlying mechanisms among diverse populations, or are there many roads to a similar phenotype? The experimental evolution of pesticide resistance in insects provides a powerful model to study the diverse evolutionary signatures of adaptation and their associated costs. Here, we selected for resistance to two pesticides (organophosphates and pyrethroids) in six field-derived populations of the red flour beetle (Tribolium castaneum). After several generations of selection, we performed transcriptomic analyses and measured survival, development, and fecundity in the presence and absence of pesticides to detect fitness costs of resistance evolution. All pesticide-selected populations exhibited significantly improved survival after pesticide exposure without substantial fitness costs, compared to control populations. Populations that evolved to resist organophosphates had distinct gene expression in the presence and absence of organophosphates, supporting different detoxification mechanisms and cuticular modifications among populations. In contrast, pyrethroid resistant populations demonstrated common differential expression of cytochrome P450 transcripts. Furthermore, some populations evolved similar mechanisms against both pesticides while others showed little overlap in their evolved responses, suggesting variation in potential cross-resistance phenotypes. Overall, between populations, we observed both parallel and divergent patterns in gene expression associated with acquired pesticide resistance, without ubiquitous fitness costs.
Effects of Climate on Performance of No-Tillage

Distribution and amount of rainfall and temperature have more direct effects upon performance of no-tillage row crops in dryland agriculture than any other climatic factors. As will be pointed out in Chapter 4, the distribution of rainfall during the growing season is very important to the maximum conservation of soil water due to no-tillage or a mulch. The more rainfall events which occur during the growing season, the greater the difference of soil water evaporation between no-tillage or a mulch and conventional tillage; therefore, the more soil water will be conserved from the no-tillage than from conventional tillage which is then available for transpiration through plants. In central Kentucky the ideal distribution and amount of rainfall to obtain near maximum conservation is about 2.5–3.0 cm of rain per week, a month prior to planting until the crop reaches full canopy, about mid-July (see Table 4-1). From Table 4-1, it can be seen that the average water use, soil water evaporation plus transpiration, by corn for the 1970, 1971, and 1972 and 1973 growing seasons (May through September) on the conventional tillage treatment were 35.5, 51.4, 35.5 and 50.6 cm, respectively. The grain yields were 6,136, 10,841, 10,841 and 8,795 for 1970, 1971, 1972 and 1973, respectively. The water use in 1970 and 1972 was the same, 35.5 cm, while grain yields were drastically different, 6,136 and 10,841 kg/ha.
Failing to find context-dependency in perceptual implicit memory: evidence against an episodic view?

As in Biederman's (1987) model of object recognition, identification of a word depends upon the parts of the word (letters/morphemes/phonemes) and their spatial location. Bower's (1986,1996) model has not been widely accepted among perceptual implicit memory researchers. The conclusion among researchers has been that views such as
Test and debug solutions for 3D-stacked integrated circuits

Three-dimensional (3D) stacking using through-silicon vias (TSVs) promises higher integration levels in a single package, keeping pace with Moore's law. Testing has been identified as a showstopper for volume manufacturing of 3D-stacked integrated circuits (3D ICs). This work provides solutions to new challenges related to 3D test content, test access, diagnosis and debug. We analyze the the impact of thermo-mechanical stress due to TSV fabrication process on test quality. We propose a test-generation flow that takes TSV-induced stress into account by using stress-aware circuit models. Pre-bond TSV test is a challenge due to limited accessibility of TSV at the pre-bond stage. We develop a non-invasive method for TSV test and diagnosis using ring oscillators, duty-cycle detectors, and a regression model based on artificial neural networks. In order to efficiently deliver test content, 3D design-for-test (DfT) architectures are needed. We propose an optimization approach that takes uncertainties in input parameters into account and provides a solution that is efficient in the presence of input-parameter variations and minimizes test time. Finally, post-silicon debug is a major challenge due to continuously increasing design complexity. We develop a low-cost debug architecture for massive signal tracing in 3D-stacked ICs with wide-I/O DRAM dies that significantly increases the observation window compared to traditional methods that use trace buffers.
Micromachined capacitive transducer arrays for intravascular ultrasound imaging

We designed, fabricated, and tested ring annular capacitive micromachined ultrasonic transducer (CMUT) arrays for forward looking intravascular ultrasound (IVUS) imaging in the 10-20MHz range. Our fabrication process uses low stress plasma enhanced chemical vapor deposition (PECVD) to form the silicon nitride membrane and provides localized vacuum sealing. The CMUT fabrication requires a maximum process temperature of 250/spl deg/C enabling post-CMOS CMUT fabrication for electronics integration. Electrical and acoustic characterization results show that the process is repeatable and the response of 40 /spl times/ 120/spl mu/m CMUT elements of a lmm diameter array are suitable for IVUS imaging around 16MHz. We also present initial volumetric imaging experiments on different targets using a 32 element CMUT-based forward looking IVUS array and synthetic aperture image reconstruction techniques.
NEW EJECTION CHAIN AND ALTERNATING PATH METHODS FOR TRAVELING SALESMAN PROBLEMS

ABSTRACT This paper introduces new ejection chain heuristics designed to generate compound move neighborhoods with attractive properties for traveling salesman problems. These procedures are based on the principle of creating a reference structure that coordinates the options for linking components of the moves generated. We illustrate the ability of a reference structure derived from a stem-and-cycle construction to produce tour transformations that correspond to (nonstandard) classes of alternating paths. Theorems are given demonstrating the existence of trajectories by these transformations that link arbitrary tours, hence making an optimal tour potentially accessible at each iteration. We also provide additional reference structures and results making it possible to generate a collection of alternating paths that precisely expresses the symmetric difference between two tours. The basic ideas underlying these approaches are given in this paper, and the more advanced formulations and methods are provided in an expanded sequel.
The complex genetic and molecular basis of a model quantitative trait

Quantitative traits are often influenced by many loci with small effects. Identifying most of these loci and resolving them to specific genes or genetic variants is challenging. Yet, achieving such a detailed understanding of quantitative traits is important, as it can improve our knowledge of the genetic and molecular basis of heritable phenotypic variation. In this study, we use a genetic mapping strategy that involves recurrent backcrossing with phenotypic selection to obtain new insights into an ecologically, industrially, and medically relevant quantitative trait-tolerance of oxidative stress, as measured based on resistance to hydrogen peroxide. We examine the genetic basis of hydrogen peroxide resistance in three related yeast crosses and detect 64 distinct genomic loci that likely influence the trait. By precisely resolving or cloning a number of these loci, we demonstrate that a broad spectrum of cellular processes contribute to hydrogen peroxide resistance, including DNA repair, scavenging of reactive oxygen species, stress-induced MAPK signaling, translation, and water transport. Consistent with the complex genetic and molecular basis of hydrogen peroxide resistance, we show two examples where multiple distinct causal genetic variants underlie what appears to be a single locus. Our results improve understanding of the genetic and molecular basis of a highly complex, model quantitative trait.
Comparative Inhibition of β-Lactamases by Novel β-Lactam Compounds

The beta-lactamase-inhibiting activity of CP-45,899, 3,3-dimethyl-7-oxo-4-thia-1-azabicylo(3,2,0)heptane-2-carboxylic acid, 4,4-dioxide [2S-(2alpha,5alpha)], was investigated and compared with the beta-lactamase-inhibiting activity of clavulanic acid and dicloxacillin. CP-45,899 was an effective inhibitor of Staphylococcus aureus beta-lactamase and of those beta-lactamases of gram-negative bacteria which are primarily active against penicillins or equally active against penicillins and cephalosporins. The reaction of CP-45,899 with beta-lactamases was a concentration- and time-dependent event. CP-45,899 acted as a competitive inhibitor of plasmid-mediated S. aureus, Escherichia coli, and Shigella sonnei beta-lactamases and inducible Klebsiella beta-lactamase. CP-45,899 was a poor inhibitor of inducible or constitutive chromosomally mediated beta-lactamases of indole-positive Proteus, Citrobacter, and Enterobacter. CP-45,899 had lower kinetic constants for inhibition of hydrolysis than did clavulanic acid against many of the beta-lactamases which both inhibited.
Early access to a neurologist reduces the rate of missed diagnosis in young strokes

Background We hypothesized that the presence of an in-house neurologist or a neurology or emergency medicine (EM) residency is associated with a lower rate of missed stroke diagnosis and a greater use of thrombolytic therapy. Methods The outpatient Young Stroke registry from our academic medical center was reviewed. Patients 16 to 50 years of age who presented with ischemic stroke were included. Information on presentation, acute therapy, and missed diagnosis was obtained. The presence of an EM or neurology residency at the presenting hospital was recorded. We also assessed whether hospital teaching status in these fields affected missed diagnosis rates, the use of thrombolysis, or stroke intervention. Results Ninety-three patients were included. Thirteen patients were misdiagnosed. In hospitals with and without a neurology residency, the missed diagnosis rate was 6.3% versus 18.0%, respectively ( P = .21). Two patients were misdiagnosed in hospitals with a neurology residency, but neither had neurology consultations in the emergency department. If these cases are removed from our analysis, the rate of missed diagnosis with and without a neurology residency is 0% versus 20.6%, respectively ( P = .008). Acute stroke therapy was administered in 17.9% of patients seen with an EM residency, compared to 2.7% without an EM residency ( P = .046). With and without a neurology residency, acute stroke therapy was administered in 25% versus 8.2% of cases, respectively ( P = .055). Conclusions Young adults with ischemic stroke seen at hospitals with a neurology residency had a lower missed diagnosis rate. The presence of an EM resident or a neurology teaching program was associated with a greater use of acute stroke therapies. These results support initiatives to triage young adults with suspected acute stroke to hospitals with access to neurologic expertise in the emergency department.
Stochastic networks and the extreme value distribution

Abstract This paper extends the extreme value theory to the problem of approximating the probability distribution of the duration of the longest path in stochastic networks and its parameters. It is demonstrated that the distribution function of the longest path can be more adequately represented by an extreme value distribution rather than by the normal distribution in most cases of interest. In particular, extreme value theory is used to derive estimates for the mean and the variance of the distribution. These estimates are compared with the simulated mean and variance as well as with estimates obtained by other estimating procedures. The new estimates are shown to be closer to the simulated mean and variance. Conditions that help determine which theory, normal or extreme value, is more applicable for a certain network are also provided.
Getting to Compliance in Forced Exercise in Rodents: A Critical Standard to Evaluate Exercise Impact in Aging-related Disorders and Disease

There is a major increase in the awareness of the positive impact of exercise on improving several disease states with neurobiological basis; these include improving cognitive function and physical performance. As a result, there is an increase in the number of animal studies employing exercise. It is argued that one intrinsic value of forced exercise is that the investigator has control over the factors that can influence the impact of exercise on behavioral outcomes, notably exercise frequency, duration, and intensity of the exercise regimen. However, compliance in forced exercise regimens may be an issue, particularly if potential confounds of employing foot-shock are to be avoided. It is also important to consider that since most cognitive and locomotor impairments strike in the aged individual, determining impact of exercise on these impairments should consider using aged rodents with a highest possible level of compliance to ensure minimal need for test subjects. Here, the pertinent steps and considerations necessary to achieve nearly 100% compliance to treadmill exercise in an aged rodent model will be presented and discussed. Notwithstanding the particular exercise regimen being employed by the investigator, our protocol should be of use to investigators that are particularly interested in the potential impact of forced exercise on aging-related impairments, including aging-related Parkinsonism and Parkinson’s disease.
Layer-by-layer self-assembly of polyelectrolyte multilayers on cross-section surfaces of multilayer polymer films: A step toward nano-patterning flexible substrates

Polyelectrolyte multilayers (PEMs) of poly(acrylic acid) (PAA)/poly(allylamine hydrochloride) (PAH) were successfully deposited onto novel nano-striped surfaces, which were generated using the cross-section surfaces of multilayer polymer films made from poly(ethylene-co-acrylic acid) (EAA) and linear low-density polyethylene (LLDPE). The procedure of PEM patterning consisted of three steps: nano-striped pattern formation, PEM deposition, and chemical crosslinking. It was observed that the PEMs were selectively deposited on the EAA layers and linked through covalent bonds, but those on LLDPE layers were washed off during sonication in water and methanol. In addition, the reactive moieties introduced by PEMs were successfully used to bond covalently with other important molecules, such as amine-terminated fluorescein. This kind of nano-striped surface with alternating wettability could serve as a template for many applications, including biomedical, separations, and electronics.
Genomic Fossils Calibrate the Long-Term Evolution of Hepadnaviruses

Because most extant viruses mutate rapidly and lack a true fossil record, their deep evolution and long-term substitution rates remain poorly understood. In addition to retroviruses, which rely on chromosomal integration for their replication, many other viruses replicate in the nucleus of their host’s cells and are therefore prone to endogenization, a process that involves integration of viral DNA into the host’s germline genome followed by long-term vertical inheritance. Such endogenous viruses are highly valuable as they provide a molecular fossil record of past viral invasions, which may be used to decipher the origins and long-term evolutionary characteristics of modern pathogenic viruses. Hepadnaviruses (Hepadnaviridae) are a family of small, partially double-stranded DNA viruses that include hepatitis B viruses. Here we report the discovery of endogenous hepadnaviruses in the genome of the zebra finch. We used a combination of cross-species analysis of orthologous insertions, molecular dating, and phylogenetic analyses to demonstrate that hepadnaviruses infiltrated repeatedly the germline genome of passerine birds. We provide evidence that some of the avian hepadnavirus integration events are at least 19 My old, which reveals a much deeper ancestry of Hepadnaviridae than could be inferred based on the coalescence times of modern hepadnaviruses. Furthermore, the remarkable sequence similarity between endogenous and extant avian hepadnaviruses (up to 75% identity) suggests that long-term substitution rates for these viruses are on the order of 10 28 substitutions per site per year, which is a 1,000-fold slower than short-term rates estimated based on the sequences of circulating hepadnaviruses. Together, these results imply a drastic shift in our understanding of the time scale of hepadnavirus evolution, and suggest that the rapid evolutionary dynamics characterizing modern avian hepadnaviruses do not reflect their mode of evolution on a deep time scale.
Nutrients, competition and plant zonation in a New England salt marsh

1 We examined the effects of nutrient availability on the competitive interactions of the New England salt marsh perennials that occupy discrete vegetational zones parallel to the shoreline. 2 Fertilized and unfertilized plots of pair-wise mixtures and monocultures of Spartina alterniflora, S. patens and Juncus gerardi were compared in order to assess the effects of nutrient addition on the competitive dynamics of these species in the field. In addition, we examined competition between some of these species and Distichlis spicata, a species common to disturbed marsh habitats. 3 After two growing seasons, changes in above-ground biomass of the species indicated that in fertilized plots, S. alterniflora outcompeted S. patens, S. patens outcompeted J. gerardi, and D. spicata outcompeted both J. gerardi and S. patens. This was the reverse of the interactions seen under ambient marsh conditions, and suggested that, under conditions of nutrient limitation, competitive dominance may result from efficient competition for nutrients. 4 Using a conceptual model of salt marsh zonation as a function of competition, physical stress and nutrient limitation, we hypothesize that a nutrient-induced reversal in the competitive dynamics among salt marsh perennials may result in modification of the pattern of plant zonation in this and similar marshes.
Group Treatment of Chronic Tension Headaches A Comparative Treatment Study

A study was conducted in a group format utilizing: (1) a behavioral package,(2) traditional psychotherapy, and (3) self-monitoring to compare the relative effects of these treatments on a chronic muscle-contraction (tension) headache population. Subjects were recruited through newspaper articles, radio announcements, and physician referrals. A total of 15 subjects were selected for participation. Subjects monitored their level of relaxation, frequency of headaches, severity and duration of headaches, type and amount of medication taken, and the degree to which the pain had disabled them. Significant improvement occurred across all these measures within the behavioral group; neither of the other two groups showed significant improvement. Subjects also monitored latency from pain onset to medication consumption and their ability to predict headaches. No significant change was found on these measures in any group.
Adjusted or unadjusted outcomes.

Abstract Background Surgeons have long maintained an interest in assessing the outcomes of their therapeutic efforts. Previously, such goals were supported by mortality and morbidity conferences or surgical audits. The latter typically focus on unadjusted rates of adverse events. While comparisons of these outcome metrics between individuals or institutions are held to portray quality of surgical care, such comparisons are compromised by the divergent risk profiles associated with the patient population in question, underscoring the import of adequate and validated risk adjustment measures. Numerous risk adjustment strategies have been developed, based either on more readily available, and thus less expensive, administrative claims data or on more reliable and robust, but more expensive, clinical data. The National Surgical Quality Improvement Program (NSQIP), which is requires abstraction of clinical data, stands as the “gold standard” for assessment of surgical quality. Data sources While risk adjustment seems essential to truly assess surgical quality, alternatives to use of clinical data continue to be explored. Some alternatives from previous works published by the author and others are briefly reviewed in this presentation. Conclusions When assessing the quality of surgical outcomes, risk adjustment seems superior. Ongoing research is needed to help achieve balance between the benefit of clinically based models and less expensive alternatives based on administrative data.
Proteases of the nematode Caenorhabditis elegans.

Abstract Crude homogenates of the soil nematode Caenorhabditis elegans exhibit strong proteolytic activity at acid pH. Several kinds of enzyme account for much of this activity: cathepsin D, a carboxyl protease which is inhibited by pepstatin and optimally active toward hemoglobin at pH 3; at least two isoelectrically distinct thiol proteases (cathepsins Cel and Ce2) which are inhibited by leupeptin and optimally active toward Z-Phe-Arg-7-amino-4-methylcoumarin amide at pH 5; and a thiol-independent leupeptin-insensitive protease (cathepsin Ce3) with optimal activity toward casein at pH 5.5. Cathepsin D is quantitatively most significant for digestion of macromolecular substrates in vitro , since proteolysis is inhibited >95% by pepstatin. Cathepsin D and the leupeptin-sensitive proteases act synergistically, but the relative contribution of the leupeptin-sensitive proteases depends upon the protein substrate.
The influence of western hemlock and western redcedar on microbial numbers, nitrogen mineralization, and nitrification

Microbial numbers in the forest floor and mineral soil (Al horizon) under large individual western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) trees were compared. The lower pH and base saturation of hemlock samples was associated with higher fungal spore counts while cedar samples had higher total microbial counts and populations of ammonium oxidizing bacteria. Nitrogen mineralization rates were greater in laboratory incubations of hemlock soil but nitrification was only observed in incubations of cedar soil. These differences in nitrogen mineralization and nitrification are aspects of species-specific nutrient cycling regimes.
The N-terminal domain of Escherichia coli ClpB enhances chaperone function.

ClpB/Hsp104 collaborates with the Hsp70 system to promote the solubilization and reactivation of proteins that misfold and aggregate following heat shock. In Escherichia coli and other eubacteria, two ClpB isoforms (ClpB95 and ClpB80) that differ by the presence or absence of a highly mobile 149-residues long N-terminus domain are synthesized from the same transcript. Whether and how the N-domain contributes to ClpB chaperone activity remains controversial. Here, we show that, whereas fusion of a 20-residues long hexahistidine extension to the N-terminus of ClpB95 interferes with its in vivo and in vitro activity, the same tag has no detectable effect on ClpB80 function. In addition, ClpB95 is more effective than ClpB80 at restoring the folding of the model protein preS2-β-galactosidase as stress severity increases, and is superior to ClpB80 in improving the high temperature growth and low temperature recovery of dnaK756 ΔclpB cells. Our results are consistent with a model in which the N-domain of ClpB95 maximizes substrate processing under conditions where the cellular supply of free DnaK–DnaJ is limiting.
An empirical investigation of interstate AFDC benefit competition

Claims that states which offer generous welfare benefits attract the poor and that some states pay low benefits intending to drive the poor away are neither uncommon nor entirely un- founded. This paper employs a two player (state) generalized game to model states' choice of a benefit level in the Aid to Families with Dependent Children (AFDC) program. Migration by the poor in response to interstate differentials in earnings and welfare opportunities, and the subse- quent changes in AFDC caseloads, drive this game. Estimation of the model (using 1979 data) suggests that states within approximately 750 miles of each other do engage in a benefit-setting game. The rival's initial number of poor and preference for non-AFDC consumption appear to be the more influential rival characteristics. These findings, while derived from a different methodological approach, are consistent with previous studies which indicate that welfare recipients tend to move toward higher benefit states. Such migration may impede the efficient spatial allocation of labor. The results also indicate that states will tend to offer lower benefits given recipient migration than would be the case otherwise. State jurisdiction over benefits consequently leads to underprovision of AFDC. Federalization of the AFDC program would improve efficiency in terms of the spatial allocation of labor and the provision of AFDC.
A comparison of OPO pulsatile machine preservation practices and results

Context—Kidney preservation has been performed by either ice (static) or machine pulsatile perfusion. Ice storage is simple, with only 1 methodology. Machine perfusion, on the other hand, is accomplished using multiple methodologies. This article delineates the different methodologies of pumping centers throughout the country.Objective—Pulsatile machine perfusion is again being viewed as the preservation method of choice for kidneys from non-heart-beating cadaver donors and cadaver kidneys from marginal donors. To develop indices to predict the viability of cadaver kidneys for transplant, a review of the organ procurement organizations, specific perfusion techniques, and a comparison of the delayed graft function and graft survival rates were considered.Methods—A survey, asking for specifics on perfusion parameters, pulsatile machine perfusion experience, and criteria for perfusion implementation and graft survival results, was mailed to all organ procurement organizations in the United States.Results—Of ...
Differentiation Versus Low Cost or Differentiation and Low Cost: A Contingency Framework

In the policy literature there is an assumption that the generic business-level strategies of differentiation and overall cost leadership are generally inconsistent. Contrary to this view, this article presents a contingency framework in which differentiation can be a means for firms to establish an overall low-cost position and discusses that a combination of differentiation and low cost may be necessary for firms to establish a sustainable competitive advantage.
Rapid maneuvering of multi-body dynamic systems with optimal motion compensation

Abstract Rapid maneuvering of multi-body dynamical systems is an important, yet challenging, problem in many applications. Even in the case of rigid bodies, it can be difficult to maintain precise control over nominally stationary links if it is required to move some of the other links quickly because of the various nonlinearities and coupled interactions that occur between the bodies. Typical control concepts treat the multi-body motion control problem in two-stages. First, the nonlinear and coupling terms are treated as disturbances and a trajectory tracking control law is designed in order to attenuate their effects. Next, motion profiles are designed, based on kinematics parameterizations, and these are used as inputs to the closed loop system to move the links. This paper describes an approach for rapid maneuvering of multi-body systems that uses optimal control theory to account for dynamic nonlinearities and coupling as part of the motion trajectory design. Incorporating appropriate operational constraints automatically compensates for these multi-body effects so that motion time can be reduced while simultaneously achieving other objectives such as reducing the excitation of selected links. Since the compensatory effect is embedded within the optimal motion trajectories, the performance improvement can be obtained even when using simple closed-loop architectures for maneuver implementation. Simulation results for minimum time control of a two-axis gimbal system and for rapid maneuvering of a TDRS single-access antenna, wherein it is desired to limit the excitation of the satellite body to which the antenna is attached, are presented to illustrate the concepts.
Genetics of polyploidy

In general, then, genetic evidence from polyploids harmonizes surprisingly well with concepts based on the modern gene-chromosome law of heredity. This is true for both the individual hereditary characters and the organism as a whole. With the former, it is evident that character inheritance follows the particular gene distribution even when the cytological mechanism is disturbed by the addition of chromosomes.