cssi/SciSciGPT-SciSciNet huggingface dataset:
Cellular traffic offloading via opportunistic networking with reinforcement learning

The widespread diffusion of mobile phones is triggering an exponential growth of mobile data traffic that is likely to cause, in the near future, considerable traffic overload issues even in last-generation cellular networks. Offloading part of the traffic to other networks is considered a very promising approach and, in particular, in this paper we consider offloading through opportunistic networks of users' devices. However, the performance of this solution strongly depends on the pattern of encounters between mobile nodes, which should therefore be taken into account when designing offloading control algorithms. In this paper we propose an adaptive offloading solution based on the Reinforcement Learning framework and we evaluate and compare the performance of two well known learning algorithms: Actor-Critic and Q-Learning. More precisely, in our solution the controller of the dissemination process, once trained, is able to select a proper number of content replicas to be injected in the opportunistic network to guarantee the timely delivery of contents to all interested users. We show that our system based on Reinforcement Learning is able to automatically learn a very efficient strategy to reduce the traffic on the cellular network, without relying on any additional context information about the opportunistic network. Our solution achieves higher level of offloading with respect to other state-of-the-art approaches, in a range of different mobility settings. Moreover, we show that a more refined learning solution, based on the Actor-Critic algorithm, is significantly more efficient than a simpler solution based on Q-Learning.
Are the two physiological races of Pollicipes polymerus (Cirripedia) genetically divided along the California coast

. Genetic work on numerous species with planktonically dispersing larvae has demonstrated gene flow throughout populations along the California coast, despite steep environmental gradients around Point Conception. Previous ecological work on a planktonically dispersing intertidal barnacle, Pollicipes polymerus, demonstrated that this species is divided into two physiological races near Point Conception, at Point Latigo. The northern race broods when water temperature either warms or cools to 14°C and the southern race broods as water warms to 20°C. I examined 8 polymorphic allozyme loci from five populations between Santa Cruz and San Diego to test if the two physiological races are genetically divided. No genetic differences were found over this geographic range, supporting a previous molecular study. These results suggest that reproductive differences between the two races of this stalked barnacle may result from plasticity in brooding activity.
Systematic Regional Variations in the Loss of Cortical Cholinergic Fibers in Alzheimer's Disease

The loss of cortical cholinergic fibers in Alzheimer's disease was investigated using choline acetyltransferase immunohistochemistry and acetylcholinesterase histochemistry. Within both the normal and Alzheimer's cerebral cortex, the two methods revealed an identical pattern of fiber staining. In the normal brain, cholinergic fiber density was highest in limbic and paralimbic cortical zones, intermediate in most sensory-motor and association zones, and lowest within the primary visual and visual association areas of the occipital lobe. In general, supragranular cortical layers contained a higher density of cholinergic fibers, and most of these were oriented vertically. In Alzheimer's disease, an overall 55% loss of cortical cholinergic fibers was detected. There was, however, marked regional variations in the extent of this loss in different cortical areas. Cortical areas within the temporal lobe, particularly the temporal association areas, displayed a dramatic loss of cholinergic fibers. By contrast, the anterior cingulate cortex, primary visual, primary somatosensory, and primary motor cortex displayed a relative preservation of cholinergic fibers. As a whole, greater loss of cholinergic fibers was detected in supragranular layers and in fibers oriented vertical to the cortical surface. These results indicate that cholinomimetic therapies are likely to have different effects on cholinergic transmission in various cortical areas. The precise mechanisms that lead to the regional variations in cortical cholinergic denervation in Alzheimer's disease remain to be elucidated.
Specific reactivity of lipid vesicles conjugated with oriented anti-lactose antibody fragments.

Abstract The method previously described (Sinha, D. and Karush, F. (1979) Biochem. Biophys. Res. Commun. 90, 554–560) for the oriented attachment of immunoglobulins to lipid vesicles has been used to confer specific reactivity on liposomes by their conjugation with anti-lactose Fab′ fragments derived from rabbit IgG antibody. It is estimated that one-third of the Fab′ fragments was irreversibly attached to liposomal membrane, resulting in a membrane concentration of 2 mmol of Fab′ per mol of total lipid. The specific reactivity of the modified liposomes was demonstrated by agglutination with a multivalent, lactose-containing diheteroglycan. The availability of virtually all of the binding sites of the attached antibody for reaction with ligand was established by a fluorescence quenching titration with N-(N ϵ - Dnp - l - lysyl )-p- aminophenyl -β- lactoside . An intrinsic association constant of 8.9 · 10 6 M −1 was found for the attached Fab′ compared to a value of 2.8 · 10 6 M −1 for free anti-lactose Fab′. In addition the maximum values for the quenching by bound ligand of the fluorescence of free and attached antibody were the same. It can be concluded that the chemical procedures used to effect attachment of the antibody to the lipid vesicles allow retention of the original structure of the antibody site and its accessibility to external components.
Culturally Competent Treatment of Posttraumatic Stress Disorder in Clinical Practice: An Ideographic, Transcultural Approach

Cultural context is a relevant factor in understanding the development, maintenance, and treatment of posttraumatic stress disorder (PTSD). Evidence suggests that the reexperiencing and arousal symptoms of PTSD represent a universal response to trauma observable across many ethnocultural groups. Variation in the expression of this response may be related to the influence of culture on the avoidance and numbing reactions to trauma. Thus, a central challenge for culturally competent treatment of PTSD does not appear to be whether to utilize empirically supported treatments for PTSD, but rather how to effectively engage individuals of various cultures in these interventions and how to address ethnocultural sources of avoidance in the maintenance of PTSD. The enormity of cultural diversity, however, presents a challenge to the task of adapting and empirically testing empirically supported treatments. An ideographic transcultural approach to cultural competency is proposed.
Revisiting the seed and soil in cancer metastasis

Metastasis remains the overwhelming cause of death for cancer patients. During metastasis, cancer cells will leave the primary tumor, intravasate into the bloodstream, arrest at a distant organ, and eventually develop into gross lesions at the secondary sites. This intricate process is influenced by innumerable factors and complex cellular interactions described in 1889 by Stephen Paget as the seed and soil hypothesis. In this review, we revisit this seed and soil hypothesis with an emerging understanding of the cancer cell (i.e. seed) and its microenvironment (i.e. soil). We will provide background to suggest that a critical outcome of the seed-soil interaction is resistance of the stresses that would otherwise impede metastasis.
Immunosuppressive effects of factor IX products: an in vitro study

The effects of a recombinant factor IX product (BeneFix), and of five plasma-derived factor IX products, AlphaNine, Immunine, Konyne, Mononine and Replinine on in vitro peripheral blood mononuclear cell (PBMC) immune function were compared in a blinded study. We assessed the effects of these products on Con-A-induced lymphocyte proliferation and interleukin-2 and interleukin-10 secretion, expression of lymphocyte activation markers, and nitric oxide secretion by stimulated mouse peritoneal macrophages. At 1 mL-1 for 48 h, Konyne reduced Con-A-induced mitogenesis by 50% (P < 0.05); AlphaNine, Mononine and BeneFix had no effect. At 10 IU mL-1, Con-A-induced mi- togenesis was at control levels with Mononine and BeneFix, but was reduced to <15% (P < 0.05) with each of the other products. IL-2 and IL-10 secretion by Con-A-stimulated lymphocytes was also markedly depressed by all the products tested except Mononine and BeneFix. Dialysis of these products did not substantially affect these results. Flow cytometric analysis of lymphocyte activation markers following Con-A stimulation showed that Konyne also decreased IL-2 receptor alpha and beta chain (CD25 and CD122) induction on PBMC. Konyne also inhibited nitric oxide secretion to levels <18% of controls. These results indicate that certain factor IX products, including some of purported higher purity, substantially depress in vitro immune function. The importance of these findings to in vivo immune function in haemophilia B patients remains to be established.
Feature Selection for Reduction of Tabular Knowledge-Based Systems

Tabular knowledge-based systems are known to be extremely versatile for verification and validation of knowledge bases. However, a major disadvantage of these systems is the combinatorial explosion that accompanies addition of new attributes or condition entries in the table. One of the means of alleviating this problem in tabular knowledge-based systems is through modularization, which is the process of breaking a big comprehensive table into smaller tables that are easy to deal with. In this study, we propose and illustrate another means to deal with this problem through use of feature selection methodology. The proposed method can be used synergistically with modularization to alleviate problems associated with combinatorial explosion in tabular knowledge bases.
The in vivo expression of pseudo ribosomal RNA genes in Drosophila melanogaster.

Electron microscopic examination of chromatin has indicated that there are two major classes of ribosomal transcription units (rTUs) in Drosophila melanogaster. (a) a standard class which is about 8 kb in length and (b) a longer class (up to 15 kb) which has been hypothesized as having an intron in the 28S region of the gene. On rare occassions, we have observed a third class of TUs, which we term pseudo rTUs (or pseudo ribosomal RNA genes), distributed among the standard rTUs. Pseudo rTUs are composed of short fiber arrays with clear gradients in their RNP fiber lengths. The pseudo rTUs observed in egg chambers and blastoderm embryos are 4.1±0.58 kb in length and are found in tandem with non-transcribed spacer regions. The lengths of the non-transcribed spacer regions are found in 2 classes: one at 4.94±1.78 kb and the other at 19.28±2.11 kb. The present information suggests that these pseudo rTU fiber arrays are ribosomal in origin as their RNP fibers crossreact with antibodies raised agains Drosophila ribosomal proteins. The pattern of distribution of D. melanogaster ribosomal protein L4 on RNP fibers in standard rTUs is compared with that in pseudo rTUs. This was determined by a novel approach involving the use of electron microscopic spreads of rTUs to which had been added IgGs labelled with polymethacrylate spheres. Pseudo ribosomal RNA genes are present in both the X (6%) and in the Y (6%) ribosomal chromatin as is indicated by their existence in nurse cells of both Oregon-R females, and females of the genotype sc4sc8/sc4sc8/y+Y.
A novel method for treatment of lumbar spinal stenosis in high-risk surgical candidates: pilot study experience with percutaneous remodeling of ligamentum flavum and lamina

Object Treatment of lumbar spinal stenosis (LSS) in chronically ill or debilitated patients is challenging. The percutaneous remodeling of ligamentum flavum and lamina (PRLL) technique is a novel method for decompression of the hypertrophic ligamentum flavum component of LSS that is performed using a fluoroscopically guided percutaneous approach, local anesthesia, and minimal sedation. Methods Fourteen patients deemed to be at high risk for complications related to open spine surgery and general anesthesia were treated using the PRLL technique. Prospectively collected visual analog scale (VAS) and Oswestry Disability Index (ODI) data were analyzed at the most recent follow-up. The average follow-up duration was 23.5 weeks. Results A statistically significant improvement in VAS scores was observed, with a reduction in pain of 53% compared with preoperative levels. In contrast, the ODI scores failed to improve. Conclusions This pilot series points to a potential new therapeutic option for LSS in high-risk s...
Regulation and the vertically integrated firm: The case of RBOC entry into interlata long distance

Congress is considering telecommunications reform legislation that would allow the Regional Bell Operating Companies (RBOCs) to enter the interLATA long-distance market. A concern is that a vertically-integrated RBOC would be able to discriminate against its rivals. A proposed remedy would require the RBOCs to reduce their access market share as a precondition to interLATA entry. We show formally that such a precondition likely contributes to higher long-distance prices and enhances the risk of discrimination. Furthermore, the lower the share of access profits retained by an RBOC, the weaker are its incentives to lower long-distance prices.
Cognitive functioning as a predictor of functional disability in later life.

Objective The contribution of cognitive functioning on multiple levels of functional disability and mortality over two years as well as individual activities of daily living (ADLs) and instrumental activities of daily living (IADLs) tasks, in a sample of older U.S. adults was examined. Methods A total of 4,077 U.S. adults (1,493 males and 2,584 females) aged ≥70 years (mean = 76.35 years) from the Second Longitudinal Study of Aging (1997/1998–1999/2000) were examined using an adapted Telephone Interview of Cognitive Status (TICS), ADLs, and IADLs. Results Multivariate logistic regression investigated cognition as a predictor of five mutually exclusive levels of functional disability. People with the lowest level of cognition had greater odds of mortality at follow-up (adjusted odds ratio [AOR] = 2.86, 95% confidence interval [CI] = 1.94–4.20), ADL and IADL disability (AOR = 1.58, 95% CI=1.15–2.16), ADL disability (AOR = 1.83, 95% CI=1.27–2.64), or IADL disability (AOR = 1.22, 95% CI=0.86–1.71) than those who were disability-free. Cognitive functioning was not predictive of individual ADL tasks but was predictive of the IADL tasks of preparing meals, shopping for groceries, managing money, telephone use, light housework, and medications but not heavy housework. Conclusion Persons with lower levels of cognitive functioning were more likely to die or become disabled than those with higher levels of cognition. Changes in cognitive functioning might serve as an early indicator of neurologic and medical factors.
Revisiting the Warburg effect in cancer cells with proteomics. The emergence of new approaches to diagnosis, prognosis and therapy

Most cancer cells exhibit elevated levels of glycolysis and this metabolic pathway seems to be related to a greater glucose uptake. This phenomenon, known as the Warburg effect, is considered one of the most fundamental metabolic alterations during malignant transformation. Originally, Warburg hypothesised that the aerobic glycolysis of cancer cells could be just an aspect of a more complex metabolic adaptation. However, this intriguing discovery was partially misinterpreted and disregarded over time. In recent years, the peculiarities of cancer cell metabolism have been re-evaluated in light of new metabolic data that seem to confirm and to widen the original concept of the Warburg effect. In fact, biochemical, molecular, and, above all, proteomic studies on the multifaceted roles of glycolytic enzymes in cancer cells in general, and in cancer stem cells in particular, seem to suggest more complex functional adaptations. These adaptations result in significantly altered protein expression patterns, and they have fundamental implications for diagnosis, prognosis and therapy. Revisiting the Warburg effect in cancer cells with a proteomic approach could deepen our knowledge of cancer cell metabolism and of cancer cell biology in general. Moreover, by identifying useful diagnostic, prognostic and therapeutic targets, it could significantly impact clinical practice.
A Bayesian Model to Predict Saturation and Logistic Growth

This paper formulates a Bayesian model to predict growth and eventual market saturation of a recently introduced (and possibly expensive) consumer-durable product. The mathematical model assumes that each new buyer buys only one item of the product, that the number of new buyers of the product in the next period of time is influenced by the current number of non-buyers and that the probability an individual will buy is the result of a diffusion of news among satisfied buyers. The solution of the prediction problem includes a two-stage Bayesian updating formula which first revises the prior distribution of market saturation based on the most recent number of new buyers and then, conditional on the saturation level, computes the predictive distribution of new buyers in future time-periods.
The Untouchables of India

The Untouchables of India. Robert Deliege. Oxford: Berg, 1999. vii. 299 pp., bibliography, index.
MoGroFunGen: A numerical model for reconstructing intra-annual growth rates of bivalve molluscs

Abstract Bivalve mollusc shells contain valuable archives of biological and environmental information. For example, periodic microgrowth increments record intra-annual growth rates that vary, in large part, as a function of temperature. Unfortunately, these increments are often not preserved, or were deposited at equivocal intervals, especially in fossils or shells with obscure increments. Here we present a new numerical model that reconstructs intra-annual growth rates by relating linear growth and time using oxygen isotopes from shell carbonate. The model involves converting observed oxygen isotope values from shell carbonate (δ18Ocarb) to temperatures, which requires knowledge of the oxygen isotope composition of water (δ18Owater). Then calculated temperatures are converted to dates using temporally calibrated temperature records. Next, dates are plotted versus sample distance (measured from sampled shells), fit with a monotonic cubic spline, and finally the first derivative of this function is evaluated yielding the growth function. The variance of this function is estimated through resampling by incorporating the uncertainty associated with δ18O measurement (e.g., ± 0.08‰). This numerical model produces a distribution of growth functions, from which we calculate the average growth function. Modeled growth functions agree well with independently derived growth functions, which suggests our modeling procedure produces reliable estimates of intra-annual growth rates. These data can, in turn, provide valuable ecological information, such as the timing of highest intra-annual growth rates, growth-limiting temperatures, and optimal growth temperatures. This final parameter is particularly important because optimal growth temperatures can now be estimated without any a priori knowledge of growth rates.
Uncovering Formula One driver performances from 1950 to 2013 by adjusting for team and competition effects

Subjective ratings of the best drivers in the history of Formula One are common, but objective analyses are hampered by the difficulties involved in comparing drivers who raced for different teams and in different eras. Here, we present a new method for comparing performances within and between eras. Using a statistical model, we estimate driver and team contributions to performance, as well as the effects of competition with other drivers. By adjusting for team and competition effects, underlying driver performances are revealed. Using this method, we compute adjusted scoring rates for 1950–2013. Driver performances are then compared using: (i) peak performances for 1-year, 3-year, and 5-year intervals; and (ii) number of championships. Overall, these comparisons rank Clark, Stewart, Fangio, Alonso, and Schumacher as the five greatest drivers. We confirm the model’s accuracy by comparing its performance predictions to 2010–2013 lap-time data. The results of the analysis are generally in good agreement with expert opinions regarding driver performances. However, the model also identifies several undervalued and overvalued driver performances, which are discussed. This is the first objective method for comparing Formula One drivers that has yielded sensible results. The model adds a valuable perspective to previous subjective analyses.
Operant behavior in dwarf hamsters (Phodopus campbelli): Effects of rate of reinforcement and reinforcer flavor variety.

Abstract We investigated operant behavior in a novel species, the dwarf hamster ( Phodopus campbelli ). In two experiments, hamsters were trained to lever-press for food reinforcement. In Experiment 1, rate of reinforcement was manipulated across conditions using four variable-interval schedules of reinforcement (delivering one to eight reinforcers per min). As predicted, within-session decreases in responding were steepest on the richest schedule. In Experiment 2, lever-pressing was reinforced by either a constant or a variety of flavored food pellets. Within-session decreases in responding were steeper when the reinforcer flavor remained constant than when it was varied within the session. In both experiments, subjects hoarded most reinforcers in their cheek pouches rather than consuming them in the operant chambers. These results are incompatible with post-ingestive satiety variables as explanations for within-session decreases in operant responding and suggest that habituation to repeatedly presented reinforcers best accounts for subjects’ response patterns. Additionally, a mathematical model that describes behavior undergoing habituation also described the present results, thus strengthening the conclusion that habituation mediates the reinforcing efficacy of food.
A tale of two internet service providers

Most ISP supervisors are aware they possess legal rights to monitor employees' Internet use. Laws such as the federal Electronic Communications Protection Act generally allow employer's great leeway to monitor employees' computer use. Yet few ISP supervisors are aware that some courts are in the process of creating a legal duty for employers to monitor their workers. Two cases in the past two years, Doe v. XYC Co. in New Jersey and Delfino v. Agilent Technologies, Inc. in California, demonstrate the increasing importance of properly managing workers' use of the Internet. This article will discuss the facts of these two cases and the relevant legal doctrines. In the first case, XYC Co. made serious mistakes and exacerbated its legal exposure, while in the second case, Aligent's prompt action allowed it to resolve its problems. Both cases provide important lessons in how to manage this imminent legal risk.
Retention of glucocorticoid by isolated mammary tissue may complicate interpretation of results from invitro experiments

When mammary gland explants from mid-pregnant rats were incubated with insulin (5 μg/ml) and [3H]cortisol (5 μg/ml) for one day, the tissue accumulated 1.69 μg cortisol/g wet tissue. During a second incubation with insulin and prolactin (5 μg/ml), only 20% of the steroid was lost per day. Such retention of glucocorticoid had an important biological consequence: the tissue exposed for one day to insulin and cortisol showed a transient stimulation of casein synthesis during a subsequent, five-day incubation with insulin and prolactin. No casein synthesis was detected, if the first culture medium contained only insulin. In conclusion, mammary gland explants from mid-pregnant rats require a glucocorticoid for casein synthesis, but this requirement may be obscured if the explants are initially incubated in medium containing cortisol, since they are capable of accumulating and retaining this steroid. Similar interpretative difficulties may arise in studies on other steroid-tissue relationships.
Subset selection in multiple linear regression: a new mathematical programming approach

A new mathematical programming model is proposed to address the subset selection problem in multiple linear regression where the objective is to select a minimal subset of predictor variables without sacrificing any explanatory power. A parametric solution of this model yields a number of efficient subsets. To obtain this solution, an optimal or one of two heuristic algorithms is repeatedly used. The subsets generated are compared to ones generated by several standard procedures. The results suggest that the new approach finds subsets that compare favorably against the standard procedures in terms of the generally accepted measure: adjusted R^2.
Production and Toxicity of the Marine Biotoxin Domoic Acid and Its Effects on Wildlife: A Review

ABSTRACT Domoic acid (DA), produced by marine diatom species in the genus Pseudo-nitzschia, is a potent excitotoxin linked since the late 1990s to massive marine mammal and seabird mortalities along the California coast. These and a previous incident involving human intoxication and deaths prompted many studies, some of which have unveiled the trophic transfer of DA from benthic invertebrates and planktivorous fish to top predators, demonstrating serious health risk to marine wildlife and humans. Top predator populations that may be more adversely affected by DA include those with narrow geographical distribution or those that are already in decline as a result of other environmental stressors or natural cyclic fluctuations. However, to date no studies have attempted to assess the population effects of recurrent exposures to DA on any of the affected wildlife species. Ecological risk assessment can help to identify DA effects on wildlife, but meaningful assessments require the integration of many types of...
DNA topology and a minimal set of basal factors for transcription by RNA polymerase II.

Abstract Immunoglobulin heavy chain (IgH) gene transcription in vitro can be reconstituted with a minimal reaction containing only TATA-binding protein (TBP), TFIIB, and RNA polymerase II (pol II) when the template is negatively supercoiled. Transcription from linear DNA templates containing either the IgH or the adenovirus major late promoters (MLPs) requires in addition TFIIF, TFIIE, TFIIH, and a fraction containing TFIIA and TFIIJ. Promoters vary in their activities in the minimal reaction. Initiation at the adenovirus MLP site was not observed in this reaction, even with templates containing negative superhelical density. When only TBP, TFIIB, and pol II were present in the reaction, the more negatively supercolled the IgH template DNA was, the more active the transcription. It is suggested that the free energy of supercolling promotes the formation of an open complex for Initiation of transcription by the minimal set of transcription factors.
Multiple reoperative coronary artery bypass grafting

Abstract Initial reoperative coronary artery bypass grafting is being performed commonly, and an increasing number of patients are being referred for subsequent reoperative coronary artery bypass grafting. From January 1980 through June 1990, 53 patients (52 male, 1 female) underwent a third or fourth coronary artery bypass operation and were retrospectively reviewed. This represented 0.3% ( 53 / 17 ,102) of the coronary artery bypass procedures done during that time period. The mean age was 59 ± 8 years. The number of grafts placed ranged from one to four with an average of 2.6 per patient. Internal mammary artery grafts were used in 30 patients (57%). The mean left ventricular ejection fraction was 0.52 ± 0.13. Intraaortic balloon pump support was necessary in 10 patients postoperatively. There were no intraoperative deaths, although 4 patients died in the postoperative hospitalization period. Perioperative myocardial infarctions were diagnosed in 6 patients, 13 patients had perioperative dysrhythmias, and 2 patients sustained a stroke. Superficial wound infections occurred in 5 patients. Late follow-up in 49 patients revealed that 2 other patients have since died, and no further myocardial infarctions have been reported in the survivors. Postoperative 3-year survival is 85%, whereas 3-year myocardial infarction-free survival is 70%. Although there is increased risk of operative complications and early death after multiple reoperative coronary artery bypass grafting, both in-hospital and long-term results suggest that it is an appropriate therapeutic strategy.
Downy Mildew Caused by Peronospora valerianellae on Corn-Salad (Valerianella locusta) in California

Corn-salad or lamb's lettuce (Valerianella locusta) is a specialty leafy green, annual vegetable grown commercially in California as a fresh market commodity used in salads. In the spring (February through April) of 2008, fields in coastal California (Monterey County) showed symptoms and signs of a downy mildew. Initial symptoms consisted of irregularly shaped, light green patches observed on adaxial leaf surfaces; these lesions later turned yellow. As disease progressed, patches became brown and necrotic. The abaxial sides of affected leaves were heavily colonized by an extensive, purplish growth characteristic of a downy mildew pathogen. Symptomatic leaves were unmarketable and diseased portions of plantings were not harvested. Crop loss was estimated to be between 1 and 15% for any one particular planting. The purple growth consisted of hyaline, branched conidiophores that emerged from stomata and had branches ending in slender, curved branchlets that did not have swollen tips. Conidia were slightly brown, ovoid, mostly nonpapillate, and measured 23.7 to 29.4 μm long × 15.9 to 22.2 μm wide. When necrotic leaf tissue was examined microscopically, thick-walled, yellow brown oospores were abundant within leaf tissues. Oospores measured 33.2 to 36.9 μm in diameter. On the basis of disease symptoms and morphology of the organism, the pathogen was identified as Peronospora valerianellae (1,3). To prove pathogenicity on corn-salad, 24 3-week-old seedlings were sprayed until runoff, using a hand-held spray bottle, with a conidial suspension (1.0 × 104 sporangia/ml), incubated for 24 h in a dew chamber (18 to 20°C), and then maintained in a greenhouse (22 to 24°C). Inoculum was obtained from one section of an affected commercial field. After 10 to 12 days, symptoms and signs of downy mildew occurred on inoculated plants, and the pathogen morphology matched that of the pathogen originally observed. Twelve untreated control plants did not develop downy mildew. To test for seedborne inoculum, 10 g of seed of each of two corn-salad cultivars were added to 100 ml of a dilute (0.05%) Tween 20 solution. The suspension was agitated for 3 h, filtered through cheesecloth to remove seed, and centrifuged. The resulting pellet was examined microscopically and found to contain low numbers of oospores that were similar in morphology to those observed in necrotic leaf lesions. To my knowledge, this is the first report of downy mildew caused by P. valerianellae on corn-salad in California and the United States. The pathogen has been reported on corn-salad in England, France, Germany, Scotland, and the Ukraine (1-3). Seedborne oospores of downy mildew have been reported on corn-salad seed tested in France (1). References: (1) R. Champion and H. Mecheneau. Seed Sci. Technol. 7:259, 1979. (2) D. F. Farr et al. Fungal Databases. Systematic Mycology and Microbiology. Online publication. ARS, USDA, 2008. (3) G. Pietrek and V. Zinkernagel. Advances in Downy Mildew Research. Kluwer Academic Publishers, Dordrecht, the Netherlands, 2002.
Beyond Slideware: How a Free-form Presentation Medium Stimulates Free-form Thinking in the Classroom

We investigate how presentation in a free-form medium stimulates free-form thinking and discussion in the classroom. Most classroom presentations utilize slideware (e.g. PowerPoint). Yet, slides add intrusive segregations that obstruct the flow of information. In contrast, in a free-form medium of presentation, content is not separated into rigid slide compartments. Instead, it is visually arranged and transformed in a continuous space.We develop a case study that investigates student experiences authoring, presenting, viewing, and discussing free-form presentations in a graduate seminar class. We analyze interviews, present a sampling of student presentations, and develop findings: free-form presentation stimulates free-form thinking, spontaneous discussion, and emergent ideation.
A Dynamic Model of Fusion Pores in Lipid Bilayers

Biological membranes remodel and change shape in processes like endocytosis, exocytosis, hemifusion, and the expansion of fusion pores. Since the length scale of these processes is generally quite small, computational models are needed to resolve the time course of the membrane. Over the past few decades, physicists and mathematicians have developed variational methods for studying time dependent changes in materials like lipid membranes. Building on a model of a single lipidic pore in a vesicle membrane, we direct the variational approach to the study of fusion pores. A fusion pore is a toroidal structure which connects two planar bilayers. The variational approach calculates the time dependent shape of the fusion pore--the precise shape of the pore that minimizes the membrane energy can be calculated using the variational method. The shape of the fusion pore is a solution to the equations of motion which include the surface forces induced by the classical Helfrich energy of the membrane. The energetics involved in the fusion pore expansion are determined as a function of the lipid composition and initial conditions. The model is based on a diffusive interface and director field approach which determines the position and energy of the membrane. The diffusive interface specifies the material properties of lipid and water, accounts for the lipid movements, and is the basis for deriving the equations of motion.
Algebraic structures in linear systems theory

A new algebraic structure, the R monoid, is associated with a discrete-time, time-invariant linear dynamical system over acommutative ring R, and its properties are investigated.
Evolved Massive Stars in the Local Group. I. Identification of Red Supergiants in NGC 6822, M31, and M33

Knowledge of the red supergiant (RSG) population of nearby galaxies allows us to probe massive star evolution as a function of metallicity; however, contamination by foreground Galactic dwarfs dominates surveys for red stars in Local Group galaxies beyond the Magellanic Clouds. Model atmospheres predict that low-gravity supergiants will have B-V values that are redder by several tenths of a magnitude than foreground dwarfs at a given V-R color, a result that is largely independent of reddening. We conduct a BVR survey of several fields in the Local Group galaxies NGC 6822, M33, and M31 as well as neighboring control fields and identify RSG candidates from CCD photometry. The survey is complete to V = 20.5, corresponding to MV = -4.5 or an Mbol of -6.3 for the reddest stars. Follow-up spectroscopy at the Ca II triplet of 130 stars is used to demonstrate that our photometric criterion for identifying RSGs is highly successful (96% for stars brighter than V = 19.5; 82% for V = 19.5-20.5). Classification spectra are also obtained for a number of stars in order to calibrate color with spectral type empirically. We find that there is a marked progression in the average (B-V)0 and (V-R)0 colors of RSGs in these three galaxies, with the higher metallicity systems having a later average spectral type, which is consistent with previous findings by Elias, Frogel, & Humphreys for the Milky Way and Magellanic Clouds. More significantly, we find that there is a clear progression with metallicity in the relative number of the highest luminosity RSGs, a trend that is apparent both in absolute visual magnitude and in bolometric luminosity. Thus any use of RSGs as distance indicators requires correction for the metallicity of the parent galaxy. Our findings are in accord with the predictions of the "Conti scenario" in which higher metallicities result in higher mass-loss rates, resulting in a star of a given luminosity spending an increasing fraction of its He-burning lifetime as a Wolf-Rayet (WR) star rather than as an RSG with increasing metallicity. The fact that the distribution of luminosities have extended tails extending to higher luminosity (with the possible exception of the M31 sample, which contains only one high-luminosity RSG) suggests that many WRs may pass through an RSG phase, albeit for a short period. We find that over the factor of 5 difference in metallicity from NGC 6822 to M31, the masses of the most luminous RSGs change by about a factor of 2, with the highest mass RSGs having masses of 25-30 M☉ in NGC 6822, 18 M☉ in M33, and 13-15 M☉ in M31. These masses are lower than the usually assumed limits for evolution to the WR stage but are not necessarily in conflict with the number of unevolved O and B stars if the time spent as a He-burning object is split between the RSG and WR phases over a large mass range.
Photonics enabled millimeter wave systems

We discuss the potential advantages of millimeter wave systems for mobile platforms and how photonic implementations will help realize these advantages in the near-future as well as identify developments required for future systems.
Beyond catastroika: Prospects for market transition in the commonwealth of independent states

The analysis of Soviet economic potential has long been marred by unstated judgments about the merits of collective ownership, price controls, egalitarianism, and administrative-command planning, to say nothing of political advocacy and commercial self-interest. The present is no exception. By and large commentators want to believe that the CIS can be swiftly refashioned into some acceptable form of market socialism that suits its purposes and those of the developed West [Kovalev, 1991; Lipton and Sach, 1991; Ozherel'ev, 1991].
An algebra for commitment protocols

Protocols enable unambiguous, smooth interactions among agents. Commitments among agents are a powerful means of developing protocols. Commitments enable flexible execution of protocols and help agents reason about protocols and plan their actions accordingly, while at the same time providing a basis for compliance checking. Multiagent systems based on commitments can conveniently and effectively model business interactions because the autonomy and heterogeneity of agents mirrors real-world businesses. Such modeling, however, requires multiagent systems to host a rich variety of protocols that can capture the needs of different applications. We show how a commitment-based semantics provides a basis for refining and aggregating protocols. We propose an approach for designing commitment protocols wherein traditional software engineering notions such as refinement and aggregation are extended to apply to protocols. We present an algebra of protocols that can be used to compose protocols by refining and merging existing ones, and does this at a level of abstraction high enough to be useful for real-world applications.
High fluid shear stress and spatial shear stress gradients affect endothelial proliferation, survival, and alignment.

Cerebral aneurysms develop near bifurcation apices, where complex hemodynamics occur: Flow impinges on the apex, accelerates into branches, then slows again distally, creating high wall shear stress (WSS) and positive and negative spatial gradients in WSS (WSSG). Endothelial responses to these kinds of high WSS hemodynamic environments are not well characterized. We examined endothelial cells (ECs) under elevated WSS and positive and negative WSSG using a flow chamber with constant-height channels to create regions of uniform WSS and converging and diverging channels to create positive and negative WSSG, respectively. Cultured bovine aortic ECs were subjected to 3.5 and 28.4 Pa with and without WSSG for 24 and 36 h. High WSS inhibited EC alignment to flow, increased EC proliferation assessed by bromodeoxyuridine incorporation, and increased apoptosis determined by terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling. These responses to high WSS were either accentuated or ameliorated by WSSG: Positive WSSG (+980 Pa/m) inhibited alignment and stimulated proliferation and apoptosis, whereas negative WSSG (−1120 Pa/m) promoted alignment and suppressed proliferation and apoptosis. These results demonstrate that ECs discriminate between positive and negative WSSG under high WSS conditions. EC responses to positive WSSG may contribute to pathogenic remodeling that occurs at bifurcations preceding aneurysm formation.
Urine from Sexually Mature Intact Male Mice Contributes to Increased Cardiovascular Responses during Free-Roaming and Restrained Conditions

Pheromones in the urine regulate aggression of male mice and castrated males produce less of these pheromones. We tested the hypothesis that pheromones in the urine of sexually mature-intact (SMI) males placed in the cage bedding of an individually housed male mouse or in a mouse restrainer would contribute to a significant increase in mean arterial pressure (MAP), heart rate (HR), and activity. Sexually mature male C57BL/6 mice were implanted with a biotelemetry transmitter to measure MAP, HR, and activity. Urine (200 μL) from SMI mice placed in the cages of singularly housed male mice caused significant changes above baseline values for MAP (21±4 mmHg), HR (145±25 bpm), and activity (9±2 counts) when compared to urine from castrated mice-induced MAP (11±3 mmHg), HR (70±15 bpm), and activity (5±1 counts). Pretreatment with terazosin significantly reduced the change in MAP (9±3 mmHg), heart rate (90±15 bpm), and activity (4±2 counts) responses to urine from SMI males. Saline did not significantly increase MAP, HR, or activity in any group. During restraint, urine from SMI mice caused a significant change in MAP (5±0.4 mmHg) and HR (17±1 bpm); urine from castrated mice did not cause a significant increase in MAP and HR. Our results demonstrate that a significant increase in MAP, HR, and activity occurs when male mice are exposed to urine pheromones from SMI males. In summary, pheromones in the urine of SMI male excreted in the cage bedding and mouse restrainers contribute to a significant increase in cardiovascular responses in the absence of direct physical contact with a different male mouse or animal handler.
Energy regulation and aging : Recent findings and their implications

Old age is a time of vulnerability to unintentional weight loss, a factor that is associated with increased morbidity and premature death. Many possible causes of weight loss in old age have been suggested. The so-called anorexia of aging may play a particular role, by either reducing food intake directly or reducing food intake in response to such adverse factors as age-associated reductions in taste and smell, poor dentition, use of multiple prescription medicines, and depression. Recent studies also raise the question of whether a reduction in dietary variety may be important. These findings emphasize the need for regular monitoring of body weight to detect unintentional weight loss in older individuals and suggest testable ways to minimize the impact of the anorexia of aging on body weight through improved dietary management.
Manufacturing-aware design methodologies for mixed-signal communication circuits

Mixed-signal communication circuits are becoming a very common component of systems-on-a-chip as part of modern communication systems. The implementation of DFM and DFT methodologies is critical to enhance communication across the tape-out barrier critical for these circuits. We present a manufacturing-aware design methodology specifically targeting integrated communication circuits in systems-on-a-chip (SoC). The key principle behind the methodology is that flexible design methods which can effectively adjust a design’s power consumption and functionality to its application can also provide critical reductions in manufacturing-induced design risk. The methodology is based on the following four techniques: goal-based design that directly relates top level goals with low level manufacturing-dependent parameters; semi-custom voltage-island physical design techniques; adaptive architecture design; and intelligent on-line at-speed monitoring and problem determination techniques. We describe these four methodology features, and illustrate them on a multi-protocol CMOS 3.2 Gbits/second low-power serial communications core. The presented data shows how this methodology results in better and more cost-effective adaptability of the design to manufacturing and post-manufacturing conditions, thereby improving turnaround time, yield, and overall profit.
The treatment paradigm shifts again on prostate cancer.

Prostate cancer has frustrated and challenged clinicians for >100 yr. Although infrequently recognized until 1890, when Von Recklinghausen reported that bone metastases often originated from the prostate, advanced prostate cancer has historically been viewed as carrying a poor prognosis. Although Hugh Hampton Young is credited with developing the radical perineal prostatectomy during the early 1900 s, he performed the surgery infrequently. The perineal approach to the prostate was much more widely used to implant radium pellets to shrink locally advanced disease. Bowel complications limited the dose that could be applied. Barringer, a prominent New York urologist, recognized that most men presented with advanced disease, and he advocated screening with regular digital rectal examinations so that the disease could be treated much earlier. This paradigm changed following Huggins’ report