cssi/SciSciGPT-SciSciNet huggingface dataset:
Restoration of spontaneously broken continuous symmetries in de Sitter spacetime.

We formulate a functional approach to scalar quantum field theory in (n+1)-dimensional de Sitter spacetime and solve the functional Schr\"odinger equation for the conformally and minimally coupled scalar fields in both the k=0 and k=1 gauges. We show that there is a natural initial condition, the requirement that the field energy remain finite as the scale factor a becomes small, which specifies a unique, time-dependent, de Sitter vacuum state. This initial condition is closely related to Hawking's prescription of including in the functional integral only those field configurations which are regular on the Euclidean section. The Green's functions constructed using this initial condition are explicitly shown to be the analytic continuation of those derived using the Euclidean path-integral formalism and the regularity (boundary) condition. These Green's functions are used to study the Hawking effect and the restoration of continuous symmetries. In particular we study the restoration of a broken O(2) symmetry of a ${\ensuremath{\Phi}}^{4}$ theory. We argue that spontaneously broken continuous symmetries are always dynamically restored in de Sitter spacetime.
Clonal Evolution in Cancer: A Tale of Twisted Twines

Intra-tumor heterogeneity of cancer cells hampers the design of effective therapies and yet it is poorly reproduced in experimental models. A recent report by Eirew at al. provides an in-depth analysis of genetic heterogeneity of breast tumor xenografts and shows that changes in clonal diversity might not be stochastic.
A radix-4 on-line division algorithm

We present an on-line algorithm for radix-4 floating point division. The divisor is first transformed in to a range such that the quotient digits are computed as a function of the scaled partial remainder only.
The role of interactive videodiscs in computer aided instruction

Abstract The use of interactive videodiscs in education and training is well documented. This computer-based technology has been applied over a wide range of educational situations. This paper discusses the differences between using microcomputer-based interactive videodiscs and “traditional” computer-aided instruction. The advantages and the disadvantages of this new technology are presented. Included is a description of development concepts in the design of interactive videodiscs. Performance results evaluating the effectiveness of this educational medium are discussed.
Discrimination training, partial reinforcement, and increases in intertrial interval all reduce response speed in a continuously reinforced key-pecking task.

Pigeons were trained in a discrete-trial task in which a response to the center key obtained illumination of a side key and a single response to the side key terminated a trial with either reinforcement or nonreinforcement. Center-key speeds (i.e., reciprocals of latencies) declined with increases in intertrial interval, and it is argued that this effect is related to a decreased likelihood as intertrial interval increases that birds will be near the key at trial onset. Side-key speeds on trials with reinforcement decreased both with increases in intertrial interval and with shifts from continuous reinforcement to either a discrimination or a partial-reinforcement condition. The effects on side-key speeds are compared with effects observed in alley-running tasks using rats, and an interpretation in terms of frustration theory is offered for the results obtained in both types of task.
Identity effects in multiple-scattering theories

The investigation of Takeda and Watson concerning the effects of the Pauli principle on the scattering of high-energy nucleons by nuclei is reconsidered and extended. Multiple-scattering and opticalmodel formalisms are found which include all identity effects in such a way so as to permit a systematic evaluation of the so-called target-exchange corrections. Although no assumptions are made concerning the number of target nucleons, the formalism is expected to be useful primarily for light nuclei.
Transportation and Regional Development in Agriculture

TRANSPORTATION has long been recognized as a strategic factor in economic growth and social change. Readily available, low-cost transportation makes it possible to bring raw materials from the mines, fields, and forests to the factory to be transformed into desired products. Likewise, dependable transportation makes it possible for these factories to supply finished products to their customers where and when they are needed and in the form and quantities desired. Without an efficient, well-managed transport system, the growth and development of an economy and/or region is adversely affected. The purpose of this paper is to discuss in general how transportation and agricultural development are interrelated in both the factor and product markets. By examining the recent innovations in rates and equipment among the various modes of transportation, an effort will be made to explain the interrelationship of these changes with the shifts in regional agricultural production patterns. Attention will also be focused on transportation changes and how they may be expected to alter the efficiency, output, and competitive structure of the agricultural industry in the future.
Intraischemic but Not Postischemic Brain Hypothermia Protects Chronically following Global Forebrain Ischemia in Rats

We investigated whether postischemic brain hypothermia (30 degrees C) would permanently protect the hippocampus following global forebrain ischemia. Global ischemia was produced in anesthetized rats by bilateral carotid artery occlusion plus hypotension (50 mm Hg). In the postischemic hypothermic group, brain temperature was maintained at 37 degrees C during the 10-min ischemic insult but reduced to 30 degrees C starting 3 min into the recirculation period and maintained at 30 degrees C for 3 h. In normothermic animals, intra- and postischemic brain temperature was maintained at 37 degrees C. After recovery for 3 days, 7 days, or 2 months, the extent of CA1 hippocampal histologic injury was quantitated. At 3 days after ischemia, postischemic hypothermia significantly protected the hippocampal CA1 sector compared with normothermic animals. For example, within the medial, middle, and lateral CA1 subsectors, the numbers of normal neurons were increased 20-, 13-, and 9-fold by postischemic hypothermia (p < 0.01). At 7 days after the ischemic insult, however, the degree of postischemic hypothermic protection was significantly reduced. In this case, the numbers of normal neurons were increased an average of only threefold compared with normothermia. Ultrastructural analysis of 7-day postischemic hypothermic rats demonstrated CA1 pyramidal neurons showing variable degrees of injury surrounded by reactive astrocytes and microglial cells. At 2 months after the ischemic insult, no trend for protection was demonstrated. In contrast to postischemic hypothermia, significant protection was seen at 2 months following intraischemic hypothermia. These data indicate that intraischemic, but not postischemic, brain hypothermia provides chronic protection to the hippocampus after transient brain ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Use of percutaneous electrical nerve stimulation (PENS) in the short-term management of headache.

Objective.–To evaluate the short-term effects of percutaneous electrical nerve stimulation (PENS) in the management of three types of chronic headache. Background.–Traditional electroanalgesic therapies have been reported to be effective in the management of acute headache symptoms. However, no controlled studies have been performed in patients with chronic headache. Methods.–Thirty patients with either tension headache, migraine, or posttraumatic headache symptoms of at least 6 months' duration were randomized to receive PENS (needles with electricity) or “needles alone” according to a crossover study design. All treatments were administered for 30 minutes, three times a week for 2 consecutive weeks with 1 week off between the two different treatments. For the PENS treatments, an alternating electrical stimulation frequency of 15 and 30 Hz was used. Pain, activity, and sleep scores were assessed using a 10-cm visual analog scale, with 0 corresponding to the best and 10 to the worst, during the 48-hour period prior to the beginning of the two treatments, immediately before and after each treatment session, and 48 hours after completing each treatment modality. Results.–Compared with the needles alone, PENS therapy was significantly more effective in decreasing the overall VAS pain scores for tension-type headache, migraine and posttraumatic headache (58%, 59%, and 52% versus 20%, 15%, and 20%, respectively). Similarly, PENS therapy produced greater improvement in the patients' physical activity (41% to 58% for PENS versus 11% to 21% for needles only) and quality of sleep (41% to 48% for PENS versus 12% to 20% for needles only). However, there were no differences in the pattern of the response to PENS therapy among the three headache groups. Conclusions.–Percutaneous electrical nerve stimulation appears to be a useful complementary therapy to analgesic and antimigraine drugs for the short-term management of headache. Interestingly, the analgesic response to PENS therapy appears to be independent of the origin of the headache symptoms.
Ligand-assisted elution chromatography for separation of lanthanides.

Abstract Lanthanides (Ln's) are the major components of rare earth elements, which are critical components of many high-value products. The ions of adjacent Ln's have the same valence and very similar ionic radii. They cannot be separated using conventional adsorption or ion exchange processes. Current production of high-purity Ln's is based on multiple sequential and parallel solvent extraction processes, which require large amounts of toxic solvents and result in serious negative impact on the environment. In this study, a ligand-assisted elution chromatography process for the separation of Ln's was developed for the first time for titania, which is a robust and inexpensive inorganic sorbent. A selective ligand for Ln's, ethylenediaminetetraacetic acid (EDTA), was found to adsorb on the sorbent. The adsorbed EDTA became strong adsorption sites for the Ln's. Desorption of Ln's was driven by reversible reactions of Ln's with EDTA in the mobile phase. The overall sorbent selectivity for the reaction and adsorption process was approximately equal to the ratio of the sorbent selectivity to the ligand selectivity. The separation mechanisms were tested and verified using rate model simulations and experimental data for the separation of praseodymium (Pr), neodymium (Nd), and samarium (Sm). Simulations based on the model were used to design efficient linear gradient elution and stepwise elution processes. The purity and yield of all three Ln's were found to be above 95% in the designed processes. Stepwise elution can be implemented in a continuous process for increasing sorbent productivity and reducing costs for large-scale separation. Ligand assisted elution processes are much simpler and more environmentally friendly than the conventional solvent extraction processes.
Magnetic cloud distortion resulting from propagation through a structured solar wind: Models and observations

[1] Numerical simulations of magnetic clouds (MCs) propagating through a structured solar wind suggest that MC-associated magnetic flux ropes are highly distorted by inhomogeneities in the ambient medium. In particular, a solar wind configuration of fast wind from high latitudes and slow wind at low latitudes, common at periods close to solar minimum, should distort the cross section of magnetic clouds into concave-outward structures. This phenomenon has been reported in observations of shock front orientations, but not in the body of magnetic clouds. In this study an analytical magnetic cloud model based upon a kinematically distorted flux rope is modified to simulate propagation through a structured medium. This new model is then used to identify specific time series signatures of the resulting concave-outward flux ropes. In situ observations of three well studied magnetic clouds are examined with comparison to the model, but the expected concave-outward signatures are not present. Indeed, the observations are better described by the convex-outward flux rope model. This may be due to a sharp latitudinal transition from fast to slow wind, resulting in a globally concave-outward flux rope, but with convex-outward signatures on a local scale.
Inhibitory effects of dorsal horn and excitant effects of ventral horn intraspinal microinjections of norepinephrine and serotonin in the cat

Abstract Norepinephrine and serotonin microinjections (10 μg) into the dorsal spinal gray matter depressed C-fiber reflexes induced by electrical stimulation of the superficial peroneal nerve or radiant heat stimulation of the footpad. Microinjection of norepinephrine or serotonin into the ventral gray matter facilitated C-fiber reflexes. These studies lend support to the suggestion that dorsal horn projections of neuronal systems which utilized norepinephrine or serotonin as neurotransmitters inhibit nociceptive spinal reflexes, and ventral horn projections facilitate spinal reflexes.
Release of Carbon Dioxide from Frozen Soil to the Arctic Atmosphere

DELINEATION of sources and sinks of CO2 is fundamental to understanding carbon cycling in an Arctic ecosystem. Kelley et al.1 observed a large, variable increase in CO2 concentration at the tundra surface over ambient air CO2 beginning a few days after the first snowfall. This increase continued into December, at which time CO2 declined to relatively stable concentrations approaching ambient air levels. CO2 at the surface increased from early May to late June until the snow disappeared. Bashenina2 also observed CO2 concentrations under the snow higher than atmospheric values. The present investigation was undertaken to explain the source of the subnivean CO2.
Enterobius vermicularis infestation of a hysterectomy specimen in a patient with a colonic reservoir

A 43-year-old woman (gravida 2, para 1011) with a history of uterine leiomyomata and a Barnett colonic reservoir underwent a supracervical hysterectomy. Final pathology revealed Enterobius vermicularis within the myometrium and adnexal vasculature. Infection may have occurred through a modified mode given the presence of a Barnett colonic reservoir and absence of an anus.
ANATOMICAL DISTRIBUTION OF T AND B LYMPHOCYTES IN THE RAT : DEVELOPMENT OF LYMPHOCYTE-SPECIFIC ANTISERA

A method is described whereby antisera raised in rabbits to rat thoracic duct lymphocytes were made specific for the plasma membrane antigens of T and B lymphocytes. These lymphocyte-specific antisera were used in immunofluorescence assays to study the distribution of B and T cells in lymphocyte containing tissues and body fluids of the rat. Rabbit antirat B-cell serum (ALSB) reacted selectively with the surfaces of lymphocytes in the lymphoid follicles of lymph node cortex and in the follicles and marginal zones of splenic white pulp, but not with the surfaces of germinal center cells or plasma cells. An identical pattern of fluorescent staining was obtained with rabbit antirat Ig serum. It was shown by blocking, absorption, and immunoprecipitation studies that ALSB was composed in large part of antibodies to rat Ig, but that it contained antibodies to other B-cell antigens as well. Rabbit antirat T-cell serum (ALST) reacted selectively with the surfaces of lymphocytes in the paracortex of lymph node and in the periarteriolar sheath of spleen, and with thymocytes. ALST did not display anti-Ig activity. ALST reacted with approximately 100% thymocytes and with 90% thoracic duct, 80% lymph node, 60% blood, 50% spleen, and 10% bone marrow lymphocytes in suspensions of cells from these sources. ALSB reacted with the remainder of the lymphocytes in the suspensions, except for bone marrow in which only 59% of lymphocytes had detectable B- or T-cell surface antigens. The population of T lymphocytes in rat bone marrow was depleted by drainage of lymphocytes from a thoracic duct fistula, thereby establishing their membership in the pool of recirculating T cells. Approximately 14% of lymphocytes issuing from the thoracic duct of TxBM donors reacted with ALST. The presence in these animals of a small number of T cells, calculated to be approximately 2% of the normal value, may account for the limited capacity of TxBM rats to respond to antigens that induce a cell-mediated immune response.
Regenerative energy management for pulse-loads in dual DC-AC micro-grids

The concept of regenerative energy management for pulse-loads in dual DC-AC micro-grids is investigated in this paper. Although this study is presented herein for electric ship power systems, the findings can also be applied for dual DC-AC micro-grids with flywheel (FW) energy storage systems. The mitigation of pulse-load effects is achieved via both the proposed system configuration and time-coordination between the occurrence of pulse-loads and kinetic energy-releases. In this paper, it is demonstrated that the kinetic energies of FW and prime-movers in an electric ship can be used to regulate the voltage of a DC distribution system in the presence of pulse-loads. This improves the stability of the overall system. The findings of this investigation are experimentally verified using a laboratory-scale micro-grid, and the test results are presented in this paper.
Conceptual and Measurement Issues in Early Parenting Practices Research: An Epidemiologic Perspective

Early parenting practices are significant to public health because of their linkages to child health outcomes. This paper focuses on the current state of the science regarding conceptual frameworks that incorporate early parenting practices in epidemiologic research and evidence supporting reliability and validity of self-report measures of such practices. Guided by a provisional definition of early parenting practices, literature searches were conducted using PubMed and Sociological Abstracts. Twenty-five published studies that included parent-report measures of early parenting practices met inclusion criteria. Findings on conceptual frameworks were analyzed qualitatively, whereas evidence of reliability and validity were organized into four domains (safety, feeding and oral health, development promotion, and discipline) and summarized in tabular form. Quantitative estimates of measures of reliability and validity were extracted, where available. We found two frameworks incorporating early parenting: one a program theory and the other a predictive model. We found no reported evidence of the reliability or validity of parent-report measures of safety or feeding and oral health practices. Evidence for reliability and validity were reported with greater frequency for development promotion and discipline practices, but report of the most pertinent type of reliability estimation, test–retest reliability, was rare. Failure to examine associations of early parenting practices with any child outcomes within most studies resulted in missed opportunities to indirectly estimate validity of parenting practice measures. Stronger evidence concerning specific measurement properties of early parenting practices is important to advancing maternal-child research, surveillance, and practice.
A finite-element/finite-difference simulation of the injection-molding filling process

Abstract A detailed formulation is presented for simulating the injection-molding filling of thin cavities of arbitrary planar geometry. The modelling is in terms of generalized Hele-Shaw flow for an inelastic, non-Newtonian fluid under non-isothermal conditions. A hybrid numerical scheme is employed in which the planar coordinates are described in terms of finite elements and the gapwise and time derivatives are expressed in terms of finite differences. The simulation is applied to the filling of a two-gated plate mold having an intentionally unbalanced runner system. Good agreement is obtained with experimental results in terms of short-shot sequences, weldline formation and pressure traces at prescribed points in the cavity.
In vivo rechargeable glucose biosensors

Abstract The development stages and evaluation of an implantable, rechargeable, glucose sensor for continuous in vivo monitoring of glucose concentration are overviewed. The present approach makes it possible to extend the sensor's lifetime by in situ sensor refilling-replacing spent immobilized enzyme with fresh enzyme. In the rechargeable biosensor the enzyme, glucose oxidase, is immobilized on dispersed carbon powder which is then held in a liquid suspension. The construction of the biosensor is such that the spent immobilized enzyme can be removed from the sensor body and fresh enzyme suspension is simultaneously injected via septa, without sensor disassembly or surgical access. The rechargeable sensor body is resistant to all of the standard procedures for sterilization including auto-claving. The sensor can be refilled with fresh enzyme material after sterilization. Rechargeable sensors based on both hydrogen peroxide and oxygen measuring principles have been under development. This biosensor, with a miniature potentiostat and signal transmitter is integrated into a small independently functioning device suitable for canine or other large animal implantation. Evaluation of the sensors and their recharging protocols in vitro and in vivo are discussed.
Autonomic Control and Mucociliary Functions

he conducting airways are innervated by the autonomic nervous system, and at least in the normal airway, mucociliary function appears to be under autonomic control. The clearance of surface liquid from the normal tracheobronchial tree is governed by the interaction among the beating cilia, the rate at which secretions are elaborated by mucus cells, the net direction and rate of transepithelial water fluxes, and the rheologic features of the fluid layer covering the epithelial surface. Several important questions arise with respect to the role of the autonomic nervous system in the control of mucociliary interaction. For example, is baseline mucociliary clearance influenced by the autonomic nervous system? Does physiologic or injurious stimulation of the airway influence mucociliary clearance by an autonomic reflex? Do all three components of the autonomic nervous system thus far identified in the airway, ie, the cholinergic, adrenergic and noncholinergic, nonadrenergic (peptidergic) system have an effect on the secretory and ciliary function of the airway mucosa? A brief review of the literature provides at least partial answers to these questions.
The effect of lesions in the centromedian nucleus of the thalamus on the monkey's performance in delayed alternation and object reversal tasks.

There is considerable anatomical and electrophysiological evidence that the centromedian nucleus is an integral part of a prefrontal system including the prefrontal cortex and the basal ganglia. It was hypothesized, therefore, that ablation of the centromedian nucleus would impair the monkey's performance on spatial delayed alternation and object discrimination reversal tasks, while leaving visual pattern discrimination undisturbed. Contrary to predictions, results indicated no impairments on any of the tasks. The implications of these findings were discussed.
Ecthyma gangrenosum in a kidney transplant recipient with pseudomonas septicemia

This report describes a renal transplant recipient in whom Pseudomonas septicemia and ecthyma gangrenosum developed within days of renal transplantation. Microscopic skin sections showed perivascular bacillary invasion. Pseudomonas organisms were cultured and microscopically visualized in sections from the transplanted kidney. Although cultures from the donor kidney preservation perfusate fluid showed no growth, Pseudomonas aeruginosa was found in the recipient's urine, blood, and peritoneal fluid. The recipient's course was complicated by septic shock, cardiopulmonary arrest, coma, and extensive skin lesions; but his condition improved with appropriate antibiotic therapy, wound debridement, and an aggressive rehabilitative program. He is now a candidate for retransplantation. This is the first known case of ecthyma gangrenosum in a renal transplant recipient.
Towards Hilbert's 24th Problem: Combinatorial Proof Invariants

Proofs Without Syntax [Hughes, D.J.D. Proofs Without Syntax. Annals of Mathematics 2006 (to appear), http://arxiv.org/abs/math/0408282 (v3). August 2004 submitted version also available: [35]] introduced polynomial-time checkable combinatorial proofs for classical propositional logic. This sequel approaches Hilbert's 24^t^hProblem with combinatorial proofs as abstract invariants for sequent calculus proofs, analogous to homotopy groups as abstract invariants for topological spaces. The paper lifts a simple, strongly normalising cut elimination from combinatorial proofs to sequent calculus, factorising away the mechanical commutations of structural rules which litter traditional syntactic cut elimination. Sequent calculus fails to be surjective onto combinatorial proofs: the paper extracts a semantically motivated closure of sequent calculus from which there is a surjection, pointing towards an abstract combinatorial refinement of Herbrand's theorem.
NEW CONCEPTS IN FEMINIZING GENITOPLASTY—IS THE FORTUNOFF FLAP OBSOLETE?

ABSTRACTPurpose: We retrospectively evaluated the results of an original technique that combines mobilization of the urogenital sinus with the creation of urogenital flaps to enlarge the vaginal introitus for 1-stage feminizing genitoplasty in children with urogenital sinus anomalies, thus, avoiding the use of posteriorly based perineal flaps.Materials and Methods: A total of 11 patients with urogenital sinus anomalies have undergone a modified Fortunoff technique combining total urogenital mobilization with the creation of urogenital sinus flaps by a single surgeon (RG) since 1998. Patient age at surgery ranged from 3 months to 13 years (mean 3.8 years). Diagnoses included congenital adrenal hyperplasia in 7 patients, cloacal malformation in 2 and urogenital sinus malformation in 2. Eight patients underwent a perineal approach and 3 underwent a posterior sagittal approach.Results: Followup ranged from 3 months to 5 years (mean 2.5 years). The cosmetic appearance was considered superior to that achieved w...
Tests of association of immunoglobulin allotype genes and viral oncogenesis in chickens

Chickens from Regional Poultry Research Laboratory (RPRL) inbred line 6(3) are resistant to virally-induced Marek's disease (MD) and lymphoid leukosis (LL) and are relatively strong regressors of virally-induced Rous sarcomas. In contrast, RPRL line 100 chickens are highly susceptible to MD and LL and are weaker regressors of Rous sarcomas than line 6(3). RPRL lines 100 and 6(3) differ for alleles at the IgG-1 (G-1) allotype locus, but have identical IgM-1 (M-1) allotype alleles. To test the possible association of the G-1 locus with variations in resistance to virally-induced tumors, homozygous and heterozygous genotypes among F3 crosses were infected. F3 chickens with different G-1 types were comparable in their resistance to MD tumors following inoculation with the JM strain of the MD virus, and for their ability to regress Rous sarcoma tumors induced by the Rous sarcoma virus (RSV) RAV-1. However, following RAV-1 virus infection a smaller proportion of G-1a/G-1aF3 or F4 birds developed LL tumors than G-1a/G-1e and G-1e/G-1e birds. Genes determining immunoglobulin heavy chains were therefore associated with a recessive resistance to B-cell lymphomagenesis in chickens.
Strongly connective degree sets II: perfect derived subgroups

When G is a finite nonabelian group, we associate the common-divisor graph with G by letting nontrivial degrees in cd(G) = {χ(1) | χ∈Irr(G)} be the vertices and making distinct vertices adjacent if they have a common nontrivial divisor. A set $${\user1{\mathcal{C}}}$$ of vertices for this graph is said to be strongly connective for cd(G) if there is some prime which divides every member of $${\user1{\mathcal{C}}}$$ , and every vertex outside of $${\user1{\mathcal{C}}}$$ is adjacent to some member of $${\user1{\mathcal{C}}}$$ . When G is nonsolvable, we provide sufficiency conditions for cd(G) to have a strongly connective subset. We also extend a previously known result about groups with nonabelian solvable quotients, and prove for arbitrary groups G that if the associated graph is connected and has a diameter bounded by 2, then indeed cd(G) has a strongly connective subset. The major focus is on when the derived subgroup G′ is perfect.
Quasi-static and dynamic fracture of graphite/epoxy composites: An optical study of loading-rate effects

Strain-rate effects on fracture behavior of unidirectional composite materials are studied. Single-edge notched multi-layered unidirectional graphite composites (T800/3900-2) are investigated to examine fracture responses under static and dynamic loading conditions using a digital speckle correlation method. The fracture parameters for growing cracks are extracted as a function of fiber orientation. A 2D digital image correlation (DIC) method is used to obtain time-resolved full-field in-plane surface displacements when specimens are subjected to quasi-static and impact loading. Stress intensity factor and crack extension histories for pure mode-I and mixed mode cases are extracted from the full-field displacements. When compared to the dynamic stress intensity factors at crack initiation, the static values are found to be consistently lower. The stress intensity factor histories exhibit a monotonic reduction under dynamic loading conditions whereas an increasing trend is seen after crack initiation under quasi-static loading cases. This is potentially due to dominant crack face fiber bridging effects in the latter cases.
Tree leaf chemical characters: selective pressures by folivorous primates and invertebrates

Plants have evolved a variety of chemical means to deter herbivory. Several studies have documented that secondary compounds are strong deterrents to certain herbivores, while others have demonstrated that some herbivores ingest large quantities of these compounds without exhibiting deleterious effects. This inconsistent response suggests that plants have evolved compounds to deter specific herbivores. Based on a study in Kibale National Park, Uganda, we explored how two major groups of herbivores, invertebrates and colobus monkeys, respond to chemical characteristics of leaves: protein, attractive from a nutritional perspective, and alkaloids, saponins and cyanogenic glycosides, which are all plant defences, detering herbivory. The intensity that colobus monkeys fed on leaves of different tree species was determined by observations (1300 h), and invertebrate herbivory was indexed by collecting leaves from 20 species and digitizing tracings to quantifying invertebrate damage. Invertebrate damage to leaves varied among species (1.5‐22.5%), but showed no relationship with saponin or protein content, or the presence or absence of alkaloids. Colobine foraging effort did not relate to the saponin and protein of leaf species, nor to the presence or absence of alkaloids. Prunus africana, the only species to test positive for cyanogenic glycosides, was fed on by colobus monkeys for 8.1% of their foraging time, but, as it occurred at low densities, it was the most preferred species. These results can be interpreted in different ways. First, it is possible that inactive compounds are retained because they increase the probability of producing new active compounds. Secondly, the indices used to evaluate compound effects may be inappropriate. For example, monkeys may only be able to tolerate a toxin to a specific threshold in a single feeding session, but our index of foraging effort was averaged over the year. Thirdly, it may be that these compounds play an active role with organisms not considered (e.g. prevent fungal attack). Finally, these compounds may serve some unknown function and selection may operate for that purpose.
Lesions of pontine and medullary reticular formation and prestimulus inhibition of the acoustic startle reaction in rats.

Abstract The effects of lesions placed within the pontine and medullary reticular formation of the rat on the inhibition of the acoustic startle reaction by auditory and visual prestimuli were examined. No lesion induced changes in the inhibitory effectiveness of either prestimulus were noted, indicating that prestimulus inhibition of startle is not effected through these regions. Observations of general home cage activity and control measures of startle response amplitude indicated a postoperative decline in reactivity following more caudally placed lesions (particularly in nucleus reticularis pontis caudalis), providing evidence against the attribution of a behavioral inhibitory function to these areas in the rat.
Analog design retargeting by design knowledge reuse and circuit synthesis

In this paper, we present an empirical method for efficient analog design retargeting by combining design knowledge reuse and circuit synthesis. The method first decomposes the source system into circuit blocks and extracts the performance parameter specifications of each circuit block. Then, it scales each circuit block and defines a design space in the target technology. Subsequently, each circuit block is synthesized. Our assumption is that if the synthesized circuit blocks retain the same set of performance specifications, then the overall system after retargeting would have the same performance specification as the source system. We experiment the method on a fourth order continuous-time Delta-Sigma modulator.
Relationships between Radar Properties at High Elevations and Surface Rain Rate: Potential Use for Spaceborne Rainfall Measurements

Abstract Ground-based radar data have been used to investigate the relationship between reflectivity at high elevations and surface rain rates. Such relations are useful for rainfall measurements by spaceborne radars at attenuating wavelength such as the 2.2-cm Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TRMM) satellite. In addition to attenuation, these relations are complicated by partial beamfilling, hail, and windshear sorting of particles, among others that affect the corresponding ground-based radar reflectivity–surface rain-rate relationships. TRMM-PR observations were simulated based on radar data from Darwin, Australia. The three-dimensional simulated data were classified by rain type according to several radar properties at high altitudes that are not seriously affected by attenuation. These properties are physical parameters relevant to the variations in the desired relationships. The resulting relationships are robust and permit the classification of near-surface...
Auctioning Patronage in Northeast Brazil: The Political Value of Money in a Ritual Market

ABSTRACT Fundraising auctions help people in a small rural town in Northeast Brazil reckon with the effects that currency stabilization and democratization have had on municipal politics. These simultaneous processes have made politics confusing for the people of Passerinho by creating multiple modalities of electoral reciprocity. In this article, I argue that the ritual procedures of the auctions commensurate these modalities of reciprocity through a semiotic procedure in which money signifies both exchange value and more personal forms of value. I consider the auction's impact on municipal politics by looking at its effect on the narrative of democratic progress and on the prestige of grassroots politicians, traditional elites, and voluntary associations.
Salt Loading Induces Redistribution of the Plasmalemmal Na/K-ATPase in Proximal Tubule Cells

Salt loading induces redistribution of the plasmalemmal Na/K- ATPase in proximal tubule cells. Background. We have reported that digitalis-like substances (cardiotonic steroids), including marinobufagenin (MBG), in- duce endocytosis of the plasmalemmal Na/K-ATPase in LLC- PK1 cells. The current report addresses the potential relevance of plasmalemmal Na/K-ATPase redistribution to in vivo salt handling. Methods. Male Sprague-Dawley rats were given 1 week of a high salt (4.0% NaCl) or normal salt (0.4% NaCl) diet. Urinary sodium excretion, as well as MBG excretion, was monitored, and proximal tubules were isolated using a Percoll gradient method. Tubular 86 Rb uptake, Na/K-ATPase enzymatic activity, and Na/K-ATPase a1 subunit density were determined. Results. The high salt diet increased urinary sodium (17.8 ± 1.8 vs. 2.5 ± 0.3 mEq/day, P < 0.01) and MBG excretion (104 ± 12 vs. 26 ± 4 pmol/day), and decreased proximal tubular 86 Rb uptake (0.44 ± 0.07 vs. 1.00 ± 0.10, P < 0.01) and Na/K- ATPase enzymatic activity (5.1 ± 1.1 vs. 9.9 ± 1.6 lmol/mg pr/hr, P < 0.01) relative to the normal diet. Proximal tubular Na/K- ATPase a1 protein density was decreased in the plasmalemma fraction but increased in both early and late endosomes fol- lowing the high salt diet. In rats fed a high salt diet, anti-MBG antibody caused a 60% reduction in urinary sodium excretion, substantial increases in proximal tubule 86 Rb uptake, and Na/K- ATPase enzymatic activity, as well as significant decreases in the early and late endosomal Na/K-ATPase a1 protein content. Conclusion. These data suggest that redistribution of the proximal tubule Na/K-ATPase in response to endogenous car- diotonic steroids plays an important role in renal adaptation to salt loading.
Gesture recognition using the Perseus architecture

Communication involves more than simply spoken information. Typical interactions use gestures to accurately and efficiently convey ideas that are more easily expressed with actions than words. A more intuitive interface with machines should involve not only speech recognition, but gesture recognition as well. One of the most frequently used and expressively powerful gestures is pointing. It is far easier and more accurate to point to an object than give a verbal description of its location. To produce a more efficient, accurate, and natural human-machine interface we use the Perseus architecture to interpret the pointing gesture. Perseus uses a variety of techniques to reliably solve this complex visual problem in non-engineered worlds. Knowledge about the task and environment is used at all stages of processing to best interpret the scene for the current situation. Once the visual operators are chosen, contextual knowledge is used to tune them for maximal performance. Redundant interpretation of the scene provides robustness to errors in interpretation. Fusion of independent types of information results in increased tolerance when assumptions about the environment fail. Windows of attention are used to improve speed and remove distractions from the scene. Furthermore, reuse is a major issue in the design of Perseus. Information about the environment and task is explicitly represented so it can easily be re-used in tasks other than pointing. A clean interface to Perseus is provided for symbolic higher level systems like the RAP reactive execution system. In this paper we describe Perseus in detail and show how it is used to locate objects pointed to by people.
Comparison of patient-reported visual outcome methods to quantify the perceptual effects of defocus

Abstract Purpose Patient-reported subjective responses have become increasingly popular in describing contact lens visual performance and discriminating between designs. The purpose of the current study is to evaluate the ability of patient-reported measures of vision to quantify the perceptual effects of defocus. Methods Ten young (18–35 years) subjects rated their subjective visual performance monocularly on 3 scales following wear of their optimal monocular distance correction and nine different blurring lenses (−0.50 to +1.50 in 0.25D steps) in a trial frame. The three scales used were a 0–100 numeric rating scale (NRS), a 100mm visual analog scale (VAS), and a 5 point ("Poor", "Fair", "Average", "Good", "Excellent") categorical rating scale (CRS). Results Mixed linear modeling results found no significant effects either for eye or trial number, but did find a significant effect due to blurring lens power ( p Conclusions The NRS and VAS yield virtually identical rating responses, but both differing slightly, however from the CRS. Each scale successfully discriminated levels of blur smaller than 0.25D with only a single measurement.
Improved minimax estimation of a normal precision matrix

Let Sp × p have a Wishart distribution with parameter matrix Σ and n degrees of freedom. We consider here the problem of estimating the precision matrix Σ−1 under the loss functions L1(σ) tr (σ) - log |σ| and L2(σ) = tr (σ). James-Stein-type estimators have been derived for an arbitrary p. We also obtain an orthogonal invariant and a diagonal invariant minimax estimator under both loss functions. A Monte-Carlo simulation study indicates that the risk improvement of the orthogonal invariant estimators over the James-Stein type estimators, the Haff (1979) estimator, and the “testimator” given by Sinha and Ghosh (1987) is substantial. Soit Sp × p une matrice aleatoire suivant une loi de Wishart avec n degres de liberte et matrice des parametres Σ. On etudie le probleme de l'estimation de Σ−1 lorsqu'un utilise les fonctions de perte: L1(σ) tr (σ) - log |σ| et L2(σ) = tr (σ). Des estimateurs de type James-Stein sont definis pour n'importe quelle valeur de p. Relativement aux deux fonctions de perte considereaes, on obtient des estimateurs minimax qui sont invariants sous les transformations orthogonales ou celles dont la matrice est triangulaire (infearieure). Une eatude de simulation Monte-Carlo indique qu'on obtient une diminution importante du risque en utilisant les estimateurs invariants sous les transformations orthogonales plutot que les estimateurs de type James-Stein, ou de Haff (1979), ou le “test-estimateur” propose par Sinha et Ghosh (1987).
Functional correlates of children's responsiveness to intervention.

Functional imaging research has yielded evidence of changes in poor readers after instructional intervention. Although it is well established that within the group of children with poor reading there are differences in behavioral response to intervention, little is know about the functional correlates of responsiveness. Therefore, we acquired functional magnetic resonance imaging (MRI) data from children identified as “at risk for reading disability” who responded differently to a reading intervention (5 responders; 5 nonresponders; 4 controls). Groups differed in activation level of the left hemisphere posterior superior temporal and the middle temporal gyri, suggesting that future imaging studies should consider responders and nonresponders separately.
Simulation of Real-Time Systems: An Object-Oriented Approach Supported by a Virtual Reality- Based Tool

This article intends to demonstrate the applicability and usefulness of virtual reality (VR) technology to support real-time systems (RTS) simulations, as a form to evaluate the correctness of such systems. The virtual reality simulation (VR-SIM), a tool which incorporates VR modeling resources, is presented. This tool offers support to simulate the behavior of RTS, checking the scheduling of processes and timing constraints. The main concepts of RTS, simulation and VR are presented, the VR-SIM architecture and functionality are described and a RTS example from the industrial area is specified and simulated. Aspects of design and implementation of the tool, following an object-oriented approach, are discussed.
Bayesian two source modeling for separation of N sources from stereo signals

We consider an enhancement to the DUET sound source separation system (Yilmaz, O. and Rickard, S., IEEE Trans. Sig. Process., 2002), which allowed for the separation of N localized sparse sources given stereo mixture signals. Specifically, we expand the system and the related delay and scale subtraction scoring (DASSS) (Master, A.S., "Sound source separation of n sources from stereo signals via fitting to n models each lacking one source", Tech. Rep., CCRMA, Stanford University, 2003) to consider cases when two sources, rather than one, are active at the same point in STFT time-frequency space. We begin with a review of the DUET system and its sparsity and independence assumptions. We then consider how the DUET system and DASSS respond when faced with two active sources, and use this information in a Bayesian context to score the probability that two particular sources are active. We conclude with a musical example illustrating the benefit of our approach.
A Tutorial of the Poisson Random Field Model in Population Genetics

Population genetics is the study of allele frequency changes driven by various evolutionary forces such as mutation, natural selection, and random genetic drift. Although natural selection is widely recognized as a bona-fide phenomenon, the extent to which it drives evolution continues to remain unclear and controversial. Various qualitative techniques, or so-called “tests of neutrality”, have been introduced to detect signatures of natural selection. A decade and a half ago, Stanley Sawyer and Daniel Hartl provided a mathematical framework, referred to as the Poisson random field (PRF), with which to determine quantitatively the intensity of selection on a particular gene or genomic region. The recent availability of large-scale genetic polymorphism data has sparked widespread interest in genome-wide investigations of natural selection. To that end, the original PRF model is of particular interest for geneticists and evolutionary genomicists. In this article, we will provide a tutorial of the mathematical derivation of the original Sawyer and Hartl PRF model.
Reaction of centrifugal nerves in perforated peripheral retina

Massive cytoid body formation of interrupted centrifugal fibers in the nerve fiber layer was observed histologically with routine methods four days after perforating trauma at the proximal aspect of a whole-thickness rupture of peripheral retina. This observation was evidence for the presence and gave an impression of the great number of centrifugal elements in the peripheral nerve fiber layer of the human retina.
Managing software reliability and support costs

There are probably 30 to 50 defects per 1000 lines of source code injected into the code at creation. The bulk of the software development process is aimed at removing these defects. The average 1-3 defects that reach the field are orders of magnitude more expensive to repair than they would have been had they been removed early in the development. A major key to managing life-cycle cost comes from reducing these latent defects that escape development initiatives and are shipped to the field. The major cause of these field-detected defects is failure to capture all the requirements correctly. Several initiatives described in this paper will aid in assuring early in the program that the requirements are correct. They are the design of experiments, failure mode and effect analysis, defect prevention process and change management. >