cssi/SciSciGPT-SciSciNet huggingface dataset:
The Method of Alternating Projections

In this chapter we will describe a theoretically powerful method for computing best approximations from a closed convex set K that is the intersection of a finite number of closed convex sets, K = ∩ 1 r K i . This method is an iterative algorithm that reduces the problem to finding best approximations from the individual sets K i . The efficacy of the method thus depends on whether the given set K can be represented as the intersection of a finite number of sets K i from which it is “easy” to compute best approximations. This will be the case, for example, when the K i are either half-spaces, hyperplanes, finite-dimensional subspaces, or certain cones. Several applications will be made to a variety of problems including solving linear equations, solving linear inequalities, computing the best isotone and best convex regression functions, and solving the general shape-preserving interpolation problem.
Role and Regulation of Proteases in Human Glioma

The invasive and destructive characteristics of malignant neoplasms in the central nervous system are of great clinical importance, as they contribute to a poor prognosis. Patients diagnosed with glioblastomas have a mean survival of only 8-12 months following surgery, chemotherapy or radiation therapy. The infiltrative growth pattern of gliomas contrasts with that of brain metastases, which most often grow with self-defined borders to the adjacent neural tissue. Whereas, the unregulated proliferation of primary brain tumor cells within the skull is a major factor in the prognosis of afflicted patients, the ability of neoplastic cells to migrate and invade surrounding normal brain tissue presents a major hurdle to successful therapeutic intervention. Brain tumor invasion is a complex phenomenon, which involves the interaction between tumor cells, normal stromal cells and the extracellular matrix (ECM). Proteolytic modification of the ECM leads to tumor cell migration into the surrounding tissue (Edwards et al 1998; Quaranta 2000; Werb et al 1999). The ECM degradation processes involve a highly organized interplay between proteases and their cellular binding sites as well as specific substrates and internalization receptors. Proteases have been known to be critically involved in a number of steps in tumor progression, such as tumor growth, invasion, migration and metastasis (Koblinski et al 2000). Members of the cysteine proteinase, serine proteinase and metalloproteinase superfamilies play functional roles in the degradation of ECM proteins (Rooprai et al 1997).
Stator Resistance Estimation Using Adaptive Estimation via a Bank of Kalman Filters

Accurate and efficient control of electric motors is dependent on knowledge of motor parameters such as the resistance and the inductance of the winding. However, these parameters are often unavailable to the control designer because they are dependent on the motor design and may change due to environmental effects such as temperature. An accurate real-time method to determine the values of these unknown parameters can improve motor performance over the entire operating range. In this work, a parameter estimation technique based on a bank of Kalman filters is used to adaptively estimate the motor winding resistance. Simulation results for a 3.5 horsepower interior permanent magnet (IPM) synchronous motor operating at rated torque demonstrate that this technique may be used for real-time estimation of motor parameters.
Multilingual Poetry Therapy

Poetry Therapy can have even greater clinical impact when used in the native language of the patient. Childhood emotions and early trauma, intellectualized when examined solely in nonnative English, can be vividly summoned through the childhood language. The use of bilingual editions of poems can evoke important emotional material while at the same time providing a structure through rhyme, rhythm and the use of metaphor. The rhyme and rhythm and phonetic associations, essential components of the full impact of the poem, are not fully reproducible in the English translation, but can be captured in bilingual versions. The tension between freedom of expression, raw emotions and highly organized structure, a basic characteristic of Poetry Therapy, is superbly exemplified through the use of bilingual poems.
A Monte Carlo direction biasing approach in the laboratory system for isotropic neutron center-of-mass scattering including hydrogen

This paper reports on a general direction biasing approach for Monte Carlo scattering simulation in a laboratory system, previously applied to neutron scattering for all elements except hydrogen for isotropic center-of-mass scattering, applied to hydrogen. (Neutron scattering with hydrogen represents a unique problem in direction biasing, in that only scattering at angles {lt}{pi}/2 are allowable.) The pertinent relationships are derived and sample results are given for problems of practical importance in neutron porosity well logging. The use of neutron hydrogen scattering direction biasing gives the same results in the problems treated as when it is not used, indicating that the treatment is valid. However, for the approach of fixing the direction biasing parameters throughout a neutron history, the addition of hydrogen direction biasing only slightly improved the Monte Carlo figure of merit, and then only when very moderate biasing is used.
Coastline extraction from repeat high resolution satellite imagery

Abstract This paper presents a new coastline extraction method that improves water classification accuracy by benefitting from an ever-increasing volume of repeated measurements from commercial satellite missions. The widely-used Normalized Difference Water Index (NDWI) method is tested on a sample of around 12,600 satellite images for statistical analysis. The core of the new water classification method is the use of a water probability algorithm based on the stacking of repeat measurements, which can mitigate the effects of translational offsets of images and the classification errors caused by clouds and cloud shadows. By integrating QuickBird, WorldView-2 and WorldView-3 multispectral images, the final data product provides a 2 m resolution coastline, as well as a 2 m water probability map and a repeat-count measurement map. Improvements on the existing coastline (GSHHS-the Global Self-consistent, Hierarchical, High-resolution Shoreline Database, 50 m–5000 m) in terms of resolution (2 m) is substantial, thanks to the combination of multiple data sources.
Bioassay for Determining the Concentrations of Caffeine and Individual Methylxanthines in Complex Samples.

ABSTRACT Caffeine and other methylxanthines are stimulant molecules found in formulated beverages, including sodas and energy drinks, and in brewed beverages, such as coffee and teas. Previously, we developed a bioassay for caffeine that involves monitoring the growth of a ΔguaB mutant of Escherichia coli defective in de novo guanine biosynthesis. When supplemented with a plasmid expressing the genes for an N-demethylation pathway from Pseudomonas putida CBB5, these bacteria demethylate caffeine (1,3,7-trimethylxanthine) and other methylxanthines into xanthine, which is then converted into guanine to support cell growth. A major limitation of this bioassay was that it could only measure the total concentration of all methylxanthines in a mixture. Therefore, it could not be used to measure the caffeine content of beverages like teas, which contain substantial quantities of multiple methylxanthines. To overcome this limitation, we created seven new plasmids containing all subsets of the three demethylase genes (ndmA, ndmB, and ndmC). We show that strains of ΔguaBE. coli containing each plasmid are able to demethylate specific subsets of methylxanthines and that they can be used to determine the concentrations of individual methylxanthines in complex mixtures containing multiple methylxanthines, including coffee doped with an additional methylxanthine. While validating this assay, we also discovered an unexpected demethylation event at the 1-methyl position when NdmB and NdmC were expressed in the absence of NdmA. The improved cell-based bioassay is inexpensive, is easy to use, and gives results comparable to standard high-performance liquid chromatography methods for measuring methylxanthine concentrations. IMPORTANCE Caffeine (1,3,7-trimethylxanthine) is the dominant neurostimulant found in coffee, teas, sodas, and energy drinks. Measuring the amount of caffeine and other methylxanthines in these beverages is important for quality assurance and safety in food science. Methylxanthines are also used in medicine and as performance-enhancing drugs, two contexts in which accurately determining their concentrations in bodily fluids is important. Liquid chromatography is the standard method for measuring methylxanthine concentrations in a sample, but it requires specialized equipment and expertise. We improved a previous bioassay that links E. coli growth to methylxanthine demethylation so that it can now be used to determine the amounts of individual methylxanthines in complex mixtures or beverages, such as coffee.
Dosage Compensation: How to Be Compensated…Or Not?

Summary Diverse dosage compensation mechanisms have evolved across species to equalize gene expression between sexes and between the sex chromosomes and autosomes. New results show that two opposite modes of dosage compensation can occur within one species, the monarch butterfly.
Developmental exposure of zebrafish to vitamin D receptor acting drugs and environmental toxicants disrupts behavioral function.

Abstract Vitamin D receptor (VDR) signaling is important for optimal neurobehavioral development. Disruption of VDR signaling by environmental toxicants during early development might contribute to the etiology of behavioral dysfunction. In the current set of studies, we examined ten compounds known to affect VDR function in vitro for neurobehavioral effects in vivo in zebrafish. Zebrafish embryos were exposed to concentrations of the compounds in their water during the first 5 days post-fertilization. On day 5, the embryos were tested in an alternating light-dark locomotor assay using a computerized video tracking system. We found that most of the compounds produced significant changes in locomotor behavior in exposed zebrafish larvae, although the direction of the effect (i.e., hypo- or hyperactivity) and the sensitivity of the effect to changes in illumination condition varied across the compounds. The nature of the behavioral effects generally corresponded to the effects these compounds have been shown to exert on VDR. These studies lay a foundation for further investigation to determine whether behavioral dysfunction persists into adulthood and if so which behavioral functions are affected. Zebrafish can be useful for screening compounds identified in high throughput in vitro assays to provide an initial test for how those compounds would affect construction and behavioral function of a complex nervous system, helping to bridge the gap between in vitro neurotoxicity assays and mammalian models for risk assessment in humans.
Display Characteristics and Their Impact on Digital Pathology: A Current Review of Pathologists' Future "Microscope"

Digital displays (monitors) are an indispensable component of a pathologists' daily workflow, from writing reports, viewing whole-slide images, or browsing the Internet. Due to a paucity of literature and experience surrounding display use and standardization in pathology, the Food and Drug Administration's (FDA) has currently restricted FDA-cleared whole-slide imaging systems to a specific model of display for each system, which at this time consists of only medical-grade (MG) displays. Further, given that a pathologists' display will essentially become their new surrogate "microscope," it becomes exceedingly important that all pathologists have a basic understanding of fundamental display properties and their functional consequences. This review seeks to: (a) define and summarize the current and emerging display technology, terminology, features, and regulation as they pertain to pathologists and review the current literature on the impact of different display types (e.g. MG vs. consumer off the shelf vs. professional grade) on pathologists' diagnostic performance and (b) discuss the impact of the recent digital pathology device componentization and the coronavirus disease 2019 public emergency on the pixel pathway and display use for remote digital pathology. Display technology has changed dramatically over the past 20 years and continues to change at a rapid rate. There is a paucity of published studies to date that investigate how display type affects pathologist performance, with more research necessary in order to develop standards and minimum specifications for displays in digital pathology. Given the complexity of modern displays, pathologists must become better informed regarding display technology if they wish to have more choice over their future "microscopes."
Neurocognitive and Neuropsychological Effects of OSA

Obstructive sleep apnea (OSA) is often associated with neuropsychological changes and cognitive impairment. While sleepiness and hypoxemia are both likely contributors to cognitive changes, the effects of OSA exceed what would be expected from these factors alone. Vascular changes related to hypertension and hyperlipidemia can play a role in the cognitive changes, as well as alterations in insulin, cortisol, leptin, and testosterone secretion or sensitivity. Finally, chronic inflammation is present in OSA, which is an additional risk factor for cognitive decline. As a result of these underlying derangements, patients with OSA show changes in attention and executive function, and the effect of OSA on mood is well documented. There are also data to suggest visuospatial impairments related to OSA. Data on learning and memory and on language functions are less conclusive. This chapter reviews the domains of cognition most commonly affected by OSA and the underlying mechanisms by which they occur. In addition, this chapter discusses the neuroimaging data used to analyze structural changes to the brain in OSA and the impacts of positive airway pressure therapy.
BYOB: How Bringing Your Own Shopping Bags Leads to Treating Yourself and the Environment

As concerns about pollution and climate change have become more central in public discourse, shopping with reusable grocery bags has been strongly promoted as environmentally and socially conscious. In parallel, firms have joined policy makers in using a variety of initiatives to reduce the use of plastic bags. However, little is known about how these initiatives might alter consumers’ in-store behavior. Using scanner panel data from a single California location of a major grocery chain, and completely controlling for consumer heterogeneity, we demonstrate that bringing your own bags simultaneously increases purchases of environmentally friendly as well as indulgent (hedonic) items. We use experimental methods to further demonstrate causality and to consider the effects of potential moderators. These findings have implications for decisions related to product pricing, placement and assortment, store layout, and the choice of strategies to increase the use of reusable bags.
Child Protective Services Guidelines for Substantiating Exposure to Domestic Violence as Maltreatment and Assigning Caregiver Responsibility: Policy Analysis and Recommendations:

The purpose of this study was to examine the range of policy approaches used by child welfare systems in the United States to guide workers in classifying and substantiating child exposure to domes...
Modified PRIEST score for identification of very low-risk COVID patients.

Abstract Background COVID-19 transmission remains high around the world, and severe local outbreaks continue to occur. Prognostic tools may be useful in crisis conditions as risk stratification can help determine resource allocation. One published tool, the Pandemic Respiratory Infection Emergency System Triage Severity Score, seems particularly promising because of its predictive ability and ease of application at the bedside. We sought to understand the performance of a modified version of this score (mPRIEST) in our institution for identifying patients with a greater than minimal risk for adverse outcome (death or organ support) at 30 days after index visit. Methods Consecutive visits at two northern Manhattan EDs with a new diagnosis of symptomatic COVID-19 were identified between November and December of 2020. Demographic variables and clinical characteristics were obtained from chart review. Outcomes were obtained from chart review and follow-up phone call. Results Outcomes were available on 306 patients. The incidence of death or mechanical ventilation at 30 days for patients in patients with mPRIEST above the threshold value was 43/181 (23.8%), and for patients below 1/125 (0.8%). The sensitivity of the score for adverse outcome was 97.7% (95% CI: 93.3% to 100%). Conclusions This data suggests the mPRIEST score, which can be calculated from clinical variables alone, has potential for use in EDs to identify patients at very low risk for adverse outcomes within 30 days of COVID diagnosis. This should be confirmed in larger formal validation studies in diverse settings.
Do We Need Support in Prepectoral Breast Reconstruction? Comparing Outcomes with and without ADM.

Background The majority of two-stage prepectoral breast reconstruction has been described utilizing acellular dermal matrix (ADM). Although reports of prepectoral breast reconstruction without ADM exist, there is a paucity of comparative studies. Methods A single-institution retrospective review was performed of consecutive patients undergoing immediate prepectoral two-stage breast reconstruction with tissue expanders from 2017 to 2019. Short-term reconstructive and aesthetic complications were compared between cases that utilized ADM for support and those that did not. Results In total, 76 cases (51 patients) were identified, of which 35 cases utilized ADM and 41 did not. Risk factors and demographics were similar between the two cohorts with the exception of body mass index, which was higher in the ADM cohort (29.3 versus 25.4, P = 0.011). Average follow-up length was also longer in patients who received ADM (20.3 versus 12.3 months, P < 0.001). Intraoperative expander fill was higher in patients who did not receive ADM (296.8 cm3 versus 151.4 cm3, P < 0.001) though final implant size was comparable in both cohorts (P = 0.584). There was no significant difference in the rate of any complication between the ADM and no ADM cohorts (25.7% versus 17.1%, respectively P = 0.357), including major mastectomy flap necrosis (P = 0.245), major infection (P = 1.000), seroma (P = 0.620), expander explantation (P = 1.000), capsular contracture (P = 1.000), implant dystopia (P = 1.000), and rippling (P = 0.362). Conclusions Immediate two-stage prepectoral breast reconstruction with tissue expanders has comparable rates of short-term complications with or without ADM support. Safety of prepectoral expander placement without ADM may warrant more selective ADM use in these cases.
Bringing hydrogel-based craniofacial therapies to the clinic.

Abstract This review explores the evolution of the use of hydrogels for craniofacial soft tissue engineering, ranging in complexity from acellular injectable fillers to fabricated, cell-laden constructs with complex compositions and architectures. Addressing both in situ and ex vivo approaches, tissue restoration secondary to trauma or tumor resection is discussed. Beginning with relatively simple epithelia of oral mucosa and gingiva, then moving to more functional units like vocal cords or soft tissues with multilayer branched structures, such as salivary glands, various approaches are presented toward the design of function-driven architectures, inspired by native tissue organization. Multiple tissue replacement paradigms are presented here, including the application of hydrogels as structural materials and as delivery platforms for cells and/or therapeutics. A practical hierarchy is proposed for hydrogel systems in craniofacial applications, based on their material and cellular complexity, spatial order, and biological cargo(s). This hierarchy reflects the regulatory complexity dictated by the Food and Drug Administration (FDA) in the United States prior to commercialization of these systems for use in humans. The wide array of available biofabrication methods, ranging from simple syringe extrusion of a biomaterial to light-based spatial patterning for complex architectures, is considered within the history of FDA-approved commercial therapies. Lastly, the review assesses the impact of these regulatory pathways on the translational potential of promising pre-clinical technologies for craniofacial applications. Statement of Significance While many commercially available hydrogel-based products are in use for the craniofacial region, most are simple formulations that either are applied topically or injected into tissue for aesthetic purposes. The academic literature previews many exciting applications that harness the versatility of hydrogels for craniofacial soft tissue engineering. One of the most exciting developments in the field is the emergence of advanced biofabrication methods to design complex hydrogels systems that can promote the functional or structural repair of tissues. To date, no clinically available hydrogel-based therapy takes full advantage of current pre-clinical advances. This review surveys the increasing complexity of the current landscape of available clinical therapies and presents a framework for future expanded use of hydrogels with an eye toward translatability and U.S. regulatory approval for craniofacial applications.
Coopting Workers under Dictatorship

What explains the variance in how authoritarian regimes treat labor? We advance a theory of why and how some dictatorships coopt workers using nominally democratic institutions, such as legislatures and political parties. When dictatorships need cooperation from society and face a potentially strong opposition, they attempt to coopt workers to reinforce their bases of support. As instruments of cooptation, legislatures and parties are useful in facilitating a political exchange between regimes and labor: dictatorships provide material benefits to workers in exchange for labor’s quiescence. As a result, institutionalized dictatorships provide more benefits to workers and experience lower levels of labor protest than their noninstitutionalized counterparts. We find empirical support for these hypotheses from a sample of all dictatorships from the 1946–96 period.
Biosurfactants: Evolution and Diversity in Bacteria

In summary, biosurfactants are an example of a class of microbial natural products that has coevolved among many genera. But whereas the biosurfactants produced in the bacterial and archaeal domains are convergent in function (suggesting that they are very important), they have developed in parallel with respect to genotype and phenotype (the surfactants are not related genetically or in terms of molecular structure). Because of this parallel evolution, currently available molecular screening techniques are of little use for the discovery of new biosurfactants. Development of such techniques will continue to be problematic because there is no relationship between the surfactants produced by different microbial genera and even species. Yet, the potential for application of biosurfactants and other natural products is great due to growing demand for biodegradable and environmentally friendly analogues for synthetic chemicals.
Negative feedback control of exocrine pancreatic secretion: Role of cholecystokinin and cholinergic pathway

Mediation of postprandial pancreatic enzyme secretion has been ascribed mainly to cholecystokinin and to vagovagal reflexes. Recent studies suggest that these pathways are subject to feedback regulation. Diversion of pancreatic juice from the duodenum stimulates cholecystokinin release and pancreatic enzyme secretion, and intraduodenal administration of trypsin or chymotrypsin inhibits cholecystokinin release and pancreatic secretion. The increased plasma cholecystokinin levels following diversion of pancreatic juice seems to be mediated by "cholecystokinin-releasing factor", a trypsin-sensitive substance secreted by the proximal small intestine. This factor may mediate pancreatic enzyme secretion in response to protein intake. Dietary protein in the intestine competes for the trypsin that would otherwise inactivate the factor. The resulting increase of this factor in the intestinal lumen releases cholecystokinin and stimulates pancreatic enzyme secretion. Enteropancreatic reflex can also be activated by distension or administration of hyperosmolar solutions in the duodenum eliciting pancreatic enzyme secretion without raising plasma cholecystokinin levels. This effect is inhibited by atropine, suggesting that it is cholinergically mediated. Pancreatic response to duodenal volume or osmolality is not suppressed by trypsin, indicating that the reflex is not affected by intraluminal proteases. Our studies also show that secretion of pancreatic polypeptide is under cholinergic control, and this peptide acts by interfering with cholinergic transmission, making it an ideal candidate to modulate pancreatic secretion stimulated by the vagal cholinergic pathway. Similar observations are made with somatostatin and calcitonin-gene related peptide which also acts preferentially to inhibit pancreatic secretion by the vagal cholinergic pathway.
Axillary lymph node failure in patients treated with accelerated partial breast irradiation

BACKGROUND: Data on the risk of axillary failure (AF) after accelerated partial breast irradiation (APBI) are limited. In this study, the authors determined the rate of AF and regional lymph node failure (RNF) in patients who received various forms of APBI and identified factors that were associated with its occurrence. METHODS: In total, 534 patients with early stage breast cancer were treated at William Beaumont Hospital with APBI, including 466 patients (87%) with invasive breast cancer and 68 patients (13%) with ductal carcinoma in situ. Clinical variables (patient age, tumor location), pathologic variables (tumor size, grade, estrogen receptor status, margin status, lymph node status), and treatment-related variables (receipt of hormone and systemic chemotherapy) were analyzed to determine which factors were associated with AF and RNF. The median length of follow-up was 63 months (range, 1-201 months). RESULTS: The 5-year actuarial AF rate was 0.19%. Three patients (0.56%) developed RNF (all patients initially had invasive breast cancer) with a 5-year actuarial rate of 0.37%. Two of the regional recurrences were in the supraclavicular fossa, and 1 was in the axilla. No variables were associated with AF. However, patient numbers were very small. The median survival after RNF was 0.8 years (range, 0.3-1.7 years), and 2 of the 3 patients died of disease. CONCLUSIONS: The rate of AF and RNF after APBI was low and appeared to be similar to the rate observed with whole-breast irradiation. No variables were associated with a higher rate of AF after APBI. Cancer 2012;. © 2011 American Cancer Society.
Influence of metering chamber volume and water level on the emitted dose of a suspension-based pMDI containing propellant 134a

Purpose. To determine the influence of metering chamber volume of a valve and water content of an aerosol formulation containing propellant 134a on dose delivery through the valve (DDV) and aerodynamic particle size distribution of the emitted dose.
Asymptotic stability of saddle points under the saddle-point dynamics

This paper considers continuously differentiable functions of two vector variables that have (possibly a continuum of) min-max saddle points. We study the asymptotic convergence properties of the associated saddle-point dynamics (gradient-descent in the first variable and gradient-ascent in the second one). We identify a suite of complementary conditions under which the set of saddle points is asymptotically stable under the saddle-point dynamics. Our first set of results is based on the convexity-concavity of the function defining the saddle-point dynamics to establish the convergence guarantees. For functions that do not enjoy this feature, our second set of results relies on properties of the linearization of the dynamics and the function along the proximal normals to the saddle set. We also provide global versions of the asymptotic convergence results. Various examples illustrate our discussion.
RESOLVING THE JUDICIAL PARADOX OF "EQUITABLE" RELIEF UNDER ERISA SECTION 502(A)(3)

The body of federal common law concerning the equitable remedies available under ERISA Section 502(a)(3) forms a virtual legal labyrinth. This article analyzes the types of claims that are possible under Section 502(a)(3). The article proposes that federal judges should look to ERISA’s underlying policy objectives when determining the, “appropriate,” equitable remedy for each type of claim that may be brought under Section 502(a)(3).
Which Fixation Device is Preferred for Surgical Treatment of Intertrochanteric Hip Fractures in the United States? A Survey of Orthopaedic Surgeons.

Background The best treatment for intertrochanteric hip fractures is controversial. The use of cephalomedullary nails has increased, whereas use of sliding hip screws has decreased despite the lack of evidence that cephalomedullary nails are more effective. As current orthopaedic trainees receive less exposure to sliding hip screws, this may continue to perpetuate the preferential use of cephalomedullary nails, with important implications for resident education, evidence-based best practices, and healthcare cost.
Detection of robustly collision-free trajectories in unpredictable environments in real-time

One of the ultimate goals in robotics is to make robots of high degrees of freedom (DOF) work autonomously in real world environments. However, real world environments are unpredictable, i.e., how the objects move are usually not known beforehand. Thus, whether a robot trajectory is collision-free or not has to be checked on-line based on sensing as the robot moves. Moreover, in order to guarantee safe motion, the motion uncertainty of the robot has to be taken into account. This paper introduces a general approach to detect if a high-DOF robot trajectory is continuously collision-free even in the presence of robot motion uncertainty in an unpredictable environment in real time. Our method is based on the novel concept of dynamic envelope, which takes advantage of progressive sensing over time without predicting motions of objects in an environment or assuming specific object motion patterns. The introduced approach can be used by general real-time motion planners to check if a candidate robot trajectory is continuously and robustly collision-free (i.e., in spite of uncertainty in the robot motion).
Modelling animal populations in changing landscapes

Models of Mobile Animal Populations (MAP models) simulate long-term land use changes, population trends and patterns of biological diversity on landscapes of 103-105 ha. MAP models can incorporate information about past land-use patterns and management practices and can project future patterns based on management plans. We illustrate this approach with an example of how implementation of a U.S. Forest Service management plan at the Savannah River Site in South Carolina, U.S.A., might influence population trends of Bachman's Sparrow Aimophila aestivalis, a relatively rare and declining species in southeastern pine forests. In this case, a management plan, largely designed to improve conditions for an endangered species, Red-cockaded Woodpecker Picoides borealis, may have a negative impact, at least in the short term, on another species of management concern, Bachman's Sparrow. In a parallel processing version of the MAP models, a single landscape that would ordinarily be too large or detailed to be simulated on a single computer is subdivided into a number of smaller landscapes, and each landscape is simulated in parallel, either on a single multi-tasking machine or on a group of networked machines. With this approach we are attempting to determine just how large a landscape must be before the dynamics of a population within it are more or less independent of factors beyond the landscape boundaries.
Remote control of ion channels and neurons through magnetic-field heating of nanoparticles

Recently, optical stimulation has begun to unravel the neuronal processing that controls certain animal behaviours. However, optical approaches are limited by the inability of visible light to penetrate deep into tissues. Here, we show an approach based on radio-frequency magnetic-field heating of nanoparticles to remotely activate temperature-sensitive cation channels in cells. Superparamagnetic ferrite nanoparticles were targeted to specific proteins on the plasma membrane of cells expressing TRPV1, and heated by a radio-frequency magnetic field. Using fluorophores as molecular thermometers, we show that the induced temperature increase is highly localized. Thermal activation of the channels triggers action potentials in cultured neurons without observable toxic effects. This approach can be adapted to stimulate other cell types and, moreover, may be used to remotely manipulate other cellular machinery for novel therapeutics.
Computer-based functional literacy: how digital literacy projects can transform the third-world workforce

Because of the cost-benefit of computer-based training (CBT), large multinational corporations now have the ability to train workers all over the world. Programs such as Tata Consultancy Services' computer-based functional literacy (CBFL) show that CBT is also an appropriate method for teaching literacy. In developing countries where American corporations are seeking to hire native workers, the governments and these corporations should combine their efforts to use CBT both to impart literacy -where needed - and to train the workforce. Technical writers can use CBFL concepts to make manuals or CBT more accessible to people in cultures where literacy does not predominate.
Structure and biochemical activities of Escherichia coli MgsA

Bacterial "maintenance of genome stability protein A" (MgsA) and related eukaryotic enzymes play important roles in cellular responses to stalled DNA replication processes. Sequence information identifies MgsA enzymes as members of the clamp loader clade of AAA+ proteins, but structural information defining the family has been limited. Here, the x-ray crystal structure of Escherichia coli MgsA is described, revealing a homotetrameric arrangement for the protein that distinguishes it from other clamp loader clade AAA+ proteins. Each MgsA protomer is composed of three elements as follows: ATP-binding and helical lid domains (conserved among AAA+ proteins) and a tetramerization domain. Although the tetramerization domains bury the greatest amount of surface area in the MgsA oligomer, each of the domains participates in oligomerization to form a highly intertwined quaternary structure. Phosphate is bound at each AAA+ ATP-binding site, but the active sites do not appear to be in a catalytically competent conformation due to displacement of Arg finger residues. E. coli MgsA is also shown to form a complex with the single-stranded DNA-binding protein through co-purification and biochemical studies. MgsA DNA-dependent ATPase activity is inhibited by single-stranded DNA-binding protein. Together, these structural and biochemical observations provide insights into the mechanisms of MgsA family AAA+ proteins.
Subcellular distribution of prolyl endopeptidase and cation-sensitive neutral endopeptidase in rabbit brain.

: The subcellular distribution of prolyl endopeptidase, and of cationsensitive neutral endopeptidase, two enzymes actively metabolizing many neuropeptides, was determined in homogenates of rabbit brain. The subcellular distribution of both enzymes was more similar to lactate dehydrogenase, a cytoplasmic enzyme marker, than to choline acetyltransferase, a synaptosomal marker. Only 35% of the activity of these two neutral endopeptidases was found in the crude mitochondrial fraction (P2), the bulk of the remaining activity being associated with the high-speed supernatant. Prolyl endopeptidase and cation-sensitive neutral endopeptidase thus can be regarded as mainly cytoplasmic enzymes in the rabbit brain.
Noninvasive early detection of brain edema in mice by near-infrared light scattering

Brain edema accounts for significant morbidity and mortality in many neurologic conditions such as head trauma, stroke, meningitis, and brain tumor. The water channel aquaporin-4 (AQP4) has been found to be an important determinant of brain water accumulation and clearance of excess brain water. We report the development of a noninvasive near-infrared (NIR) light-scattering method to compare the early kinetics of brain swelling in normal and AQP4-deficient mice. Brain tissue was illuminated through the intact skull with NIR light at 850 nm, and steady-state scattered light intensity was monitored at an angle of 90 degrees at a position on the skull approximately 10 mm from the illuminated site. NIR light scattering reversibly increased with brain swelling (DeltaI/Io approximately 25% per 1% increase in brain water content), but was insensitive to changes in cerebral blood flow, blood oxygenation, or blood flow-related changes in intracranial pressure (ICP). DeltaI/Io increased approximately linearly with brain water content as measured by wet-to-dry weight ratios. Acute water intoxication (intraperitoneal water, 20% body weight) produced a gradual increase in DeltaI/Io of 12 +/- 4% in wild-type mice at 5 min, much greater than that of 2 +/- 1% in AQP4-null mice. Correlation of the NIR signal with ICP showed that increased DeltaI/Io preceded measurable increases in ICP, indicating the ability of the NIR method to detect early brain edema before ICP elevation. NIR light scattering provides a simple noninvasive method to monitor brain edema in mice, with potential clinical applications.
Guidance and stable and unstable manifolds with input

The theory in this paper is motivated by the problem of aircraft guidance in automatic flight control, in which plant models are nonlinear. This leads us to consider the stable inversion problem, which in turn can be cast as the problem of finding a bounded solution of a time-varying nonlinear system subject to a bounded input. Under the appropriate assumptions there is a unique bounded (for all time) continuous solution to this time-varying nonlinear system in response to the bounded (for all time) input. We show that there is a (local) stable manifold containing all bounded continuous solutions for non-negative time, and that all such solutions converge to the aforementioned unique solution as time goes to infinity. Likewise there is a (local) unstable manifold containing all bounded solutions for non-positive time and these converge to the unique solution as time goes to minus infinity. In fact, the unique solution (cross the time axis) is the intersection of the stable and unstable manifolds. Copyright © 1999 John Wiley & Sons, Ltd.
Control procedures for slotted Aloha systems that achieve stability

A class of slotted ALOHA dynamic control strategies is considered. These strategies are simple to implement and can yield lossless and stable operation for arbitrarily large user populations with aggregate arrival rates below e-1 packets/slot. An ergodicity analysis is given that provides conditions on the system parameters, such that any specified set of control parameters that satisfies the given conditions is guaranteed to yield stable performance. The system state is modelled as a two-dimensional Markov chain that incorporates the backlog (the number of packets awaiting retransmission) and the estimate of the backlog. The geometrical concepts are illustrated by figures corresponding to an example case. Simulation results are presented that compare alternative control schemes.
Restenosis 1 to 24 months after clinically successful coronary balloon angioplasty: A necropsy study of 20 patients

Abstract This report describes clinical, morphologic and histologic findings at necropsy late (range 1.6 to 24.1 months [average 8.2 months]) after clinically successful coronary balloon angioplasty in 20 patients with coronary angioplasty restenosis. Clinical evidence of restenosis occurred in 14 patients (70%), including 6 patients with sudden coronary death. Of the 20 patients, 14 (70%) had a cardiac cause of death and 6 (30%) had a noncardiac cause of death. Two major subgroups of histologic findings were observed: 1) intimal proliferation (60%), and 2) atherosclerotic plaque only (40%). Of the eight sites with atherosclerotic plaque only, six were eccentric lesions and two were concentric lesions. No morphologic evidence of previous angioplasty injury (cracks, breaks, tears) was observed in the eight patients with atherosclerotic plaque only. Proposed mechanisms for the development of intimal proliferation involve the reaction of smooth muscle cells and platelets, whereas elastic recoil of overstretched eccentric or concentric atherosclerotic lesions represents the most likely explanation for the findings in the latter subgroup. On the basis of these morphologic findings at angioplasty restenosis sites, specific treatment strategies for restenosis after coronary artery balloon angioplasty are proposed.
Potentiometric iodide ion sensor based on a conducting poly(3-methylthiophene) polymer film electrode

Abstract A potentiometric iodide-selective electrode based on a poly(3-methylthiophene) (PMeT) films was developed. Graphite electrodes wer first coated with PMeT and then iodine was incorporated (doped) into the polymer film by electrochemical oxidation of iodide at +0.70 V. The effects of various electroactivation parameters such as doping potential, polymer film thickness, dopant concentration and doping period were examined in relation to the slope and linearity of calibration graphs. The performance of the electrode with respect to electrode reproducibility, response stability, appropriate pH range and response time was also examined. The polymer-based iodide-selective electrode was found to be suitable for the measurement of iodide concentrations down to 1 × 10 −6 M and its selectivity coefficients for most of the potential interferents were of the order of 1 × 10 −3 . However, certain species that deplete the iodine in the polymer matrix adversely affected the electrode response.
Magnetite surface area titration using nitric oxide

Abstract The adsorption of nitric oxide on unsupported Fe 3 O 4 has been investigated. Consistent with previous studies, the rate of adsorption follows Elovich kinetics, and the adsorption isotherm obeys the Freundlich equation over the range from 0.133 to 27 kPa at 273 K. However, the time of evacuation of the sample at 650 K prior to NO adsorption is shown to be critical for obtaining reproducible results. Specifically, if the evacuation is carried out for 1 hr, then consistent values of the NO uptake are subsequently obtained. Furthermore, this NO uptake normalized by the nitrogen BET monolayer capacity gives an estimate of the surface cation density that agrees with model calculations based on various low index faces of magnetite. On the other hand, long (ca. 25 hr) evacuation of the sample leads to a reduction of the surface oxidation state resulting in additional NO uptake and reduction of NO to primarily N 2 O.
E-provider evaluation: an exploratory study

Companies engaged in e-commerce (EC) activities are continually looking for more sophisticated and relevant capabilities and e-providers are beginning to respond with promised improvements and innovations. However it has been difficult, and sometimes almost impossible, to perform comparative evaluations of e-providers prior to the adoption of their products. It is evident that an identification of critical provider evaluation criteria and attendant quantification of benefits would aid both EC users and e-providers. This study collects and analyses data from 103 companies to identify and prioritise evaluation criteria and provider characteristics that are associated with goal performance in EC projects. A set of anticipations are developed about the effects of project spend on evaluation process attributes, and about evaluation criteria and their association with goal performance. Significant differences were found between small and large e-projects in their ranking of evaluation criteria, as well as in how provider characteristics are associated with project performance outcomes in different sized projects. The implications of these findings are discussed at length.
Particle Simulation Models for Low Frequency Microinstabilities in a Magnetic Field

Several numerical plasma simulation models using particles are described which are appropriate for low frequency electrostatic and electromagnetic microinstabilities in a strong magnetic field. The model makes use of the guiding center drift approximations for the electrons while the ions are represented either as particles obeying the equation of motion with the full Lorentz force or a fluid which includes finite-Larmor-radius effects. These models are particularly useful for studying low frequency microinstabilities (ω ≲ wpi, Ω i ) propagating nearly perpendicular to an external magnetic field (k⊥ >> k‖).
Effects of nicotine and mecamylamine-induced withdrawal on extracellular dopamine and acetylcholine in the rat nucleus accumbens.

Rationale: Prior research suggests that high levels of acetylcholine (ACh) in the nucleus accumbens (NAc) are associated with aversive states such as mor- phine withdrawal, but this has not been tested for nico- tine withdrawal. Objectives: The goal was to test the hy- pothesis that acute nicotine decreases extracellular ACh and increases extracellular dopamine (DA) in the NAc, while withdrawal from nicotine causes an opposite neu- rochemical imbalance with high extracellular ACh and low DA. Methods: Rats were prepared with a microdial- ysis probe in the NAc (primarily the shell region). They received one injection of nicotine (0.5 mg/kg, s.c.) or chronic nicotine (9 mg/kg per day via osmotic mini- pump). Results: Naive animals receiving acute nicotine showed a mild, significant increase in both ACh (122% of baseline) and DA (124%). After chronic nicotine ad- ministration for 7 days, the nicotinic antagonist meca- mylamine (1.0 mg/kg, s.c.) precipitated withdrawal with the appearance of somatic signs (teeth chattering and shakes/tremors) and a significant increase in extracellu- lar ACh to 125% of baseline, while extracellular DA de- creased to 65%. Control groups receiving saline in place of nicotine or mecamylamine did not show these effects. Conclusions: Earlier work suggests that the observed re- lease of accumbens ACh and DA in response to acute nicotine administration may be a factor in nicotine- induced suppression of appetite. ACh release during withdrawal, coupled with the decrease in extracellular DA may play a role in the aversive aspects of nicotine withdrawal that contribute to dependency.