cssi/SciSciGPT-SciSciNet huggingface dataset:
In vitro characterization of scaffold-free three-dimensional mesenchymal stem cell aggregates

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation along multiple cell lineages and have potential applications in a wide range of therapies. These cells are commonly cultured as monolayers on tissue culture plastic but possibly lose their cell-specific properties with time in vitro. There is growing interest in culturing adherent cells via three-dimensional (3D) techniques in order to recapitulate 3D in vivo conditions. We describe a novel method for generating and culturing rabbit MSCs as scaffold-free 3D cell aggregates by using micropatterned wells via a forced aggregation technique. The viability and proliferative capability of MSC aggregates were assessed via Live/Dead staining and 5-ethynyl-2’-deoxyuridine (EdU) incorporation. Enzyme-linked immunosorbent assay and antibody-based multiplex protein assays were used to quantify released growth factors and chemokines. The gene expression profile of MSCs as 3D aggregates relative to MSCs grown as monolayers was evaluated via quantitative real-time polymerase chain reaction. The rabbit MSCs were able to form compact cell aggregates and remained viable in 3D culture for up to 7 days. We also demonstrated enhanced gene and protein expression related to angiogenesis and wound healing in MSCs cultured under 3D conditions. In vitro tube formation and scratch assay revealed superior neovessel formation and greater cell recovery and migration in response to 3D conditioned media after wounding. Our data further suggest that adipose-derived stem cell aggregates have greater potential than dermal fibroblasts or bone-marrow-derived MSCs in accelerating wound healing and reducing scarring.
Optical properties of a two-dimensional electron gas: Evolution of spectra from excitons to Fermi-edge singularities.

The evolution of the absorption and emission spectrum from an exciton to a Fermi-edge singularity as a function of a quasi-two-dimensional electron-gas density is examined. Band-gap renormalization, screening, shake up of the Fermi sea, and the effect of the finite hole mass are included. The real-time response of the Fermi sea to the creation and annihilation of the hole in the valence band is treated nonperturbatively. The time evolution of the self-energy and vertex corrections is shown to be governed by a set of nonlinear differential equations, which allows for a very efficient numerical solution. The effect of the finite hole mass is to wash out the Fermi-edge singularity in absorption.
Time since Introduction, Seed Mass, and Genome Size Predict Successful Invaders among the Cultivated Vascular Plants of Hawaii

Extensive economic and environmental damage has been caused by invasive exotic plant species in many ecosystems worldwide. Many comparative studies have therefore attempted to predict, from biological traits, which species among the pool of naturalized non-natives become invasive. However, few studies have investigated which species establish and/or become pests from the larger pool of introduced species and controlled for time since introduction. Here we present results from a study aimed at quantifying predicting three classes of invasive species cultivated in Hawaii. Of 7,866 ornamental species cultivated in Hawaii between 1840 and 1999, 420 (5.3%) species naturalized, 141 (1.8%) have been classified as weeds, and 39 (0.5%) were listed by the state of Hawaii as noxious. Of the 815 species introduced >80 years ago, 253 (31%) have naturalized, 90 (11%) are classed as weeds, and 22 (3%) as noxious by the state of Hawaii. Using boosted regression trees we classified each group with nearly 90% accuracy, despite incompleteness of data and the low proportion of naturalized or pest species. Key biological predictors were seed mass and highest chromosome number standardized by genus which, when data on residence time was removed, were able to predict all three groups with 76–82% accuracy. We conclude that, when focused on a single region, screening for potential weeds or noxious plants based on a small set of biological traits can be achieved with sufficient accuracy for policy and management purposes.
Radiosensitizing and anti-proliferative effects of resveratrol in two human cervical tumor cell lines.

Abstract Resveratrol is a polyphenol isolated from the skins of grapes that has been shown to significantly alter the cellular physiology of tumor cells, as well as block the process of initiation and progression. At least one mechanism for the intracellular actions of resveratrol involves the suppression of prostaglandin (PG) biosynthesis. The involvement of PGs and other eicosanoids in the development of human cancer is well established. PGs are synthesized from arachidonic acid via the cyclooxygenase pathway and have multiple physiological and pathological functions. In addition, evidence has arisen suggesting that PGs may be implicated in the cytotoxic and/or cytoprotective response of tumor cells to ionizing radiation (IR). As such, we hypothesized that tumor cells may exhibit changes in the cellular response to IR following exposure to resveratrol, a naturally occuring compound that inhibits cyclooxygenase-1 (COX-1) activity. Thus, clonogenic cell survival assays were performed using irradiated HeLa and SiHa cells pretreated with resveratrol prior to IR exposure, and resulted in enhanced tumor cell killing by IR in a dose-dependent manner. Further analysis of COX-1 inhibition indicated that resveratrol pretreatment: (1), inhibited cell division as assayed by growth curves; and (2), induced an early S phase cell cycle checkpoint arrest, as demonstrated by fluorescence-activated cell sorting, as well as bromodeoxyuridine pulse-chase analysis. These results suggest that resveratrol alters both cell cycle progression and the cytotoxic response to IR in two cervical tumor cell lines.
Does Rotation Alone Determine Whether an A-type Star’s Spectrum is Abnormal or Normal?

The principal abnormalities among A-type stars are the metallic-line (Am) and peculiar A (Ap) stars. In these, diffusion (Michaud 1980) occurring in stars rotating at less than about 120km 8 -1 allows certain elements to sink and others to rise into the atmosphere. Observationally, all Am and Ap stars are observed to have rotational velocities less than that limit and most of the normal stars have higher rotational velocities. But a large study (Abt&Morrell 1995) showed that 15-20% of the normal stars had lower rotational velocities. Could it be that rotation alone does not determine whether a slow rotator has an abnormal or normal spectrum?
Automating the analysis of EEG recordings from prematurely-born infants: A Bayesian approach

Objective To implement an automated analysis of EEG recordings from prematurely-born infants and thus provide objective, reproducible results. Methods Bayesian probability theory is employed to compute the posterior probability for developmental features of interest in EEG recordings. Currently, these features include smooth delta waves (0.5–1.5 Hz, >100 μV), delta brushes (delta portion: 0.5–1.5 Hz, >100 μV; “brush” portion: 8–22 Hz, Results When compared with experienced electroencephalographers, the algorithm had a true positive rate between 72% and 79% for the identification of delta waves (smooth or “brush”) and interburst intervals, which is comparable to the inter-rater reliability. When distinguishing between smooth delta waves and delta brushes, the algorithm’s true positive rate was between 53% and 88%, which is slightly less than the inter-rater reliability. Conclusion Bayesian probability theory can be employed to consistently identify features of EEG recordings from premature infants. Significance The identification of features in EEG recordings provides a first step towards the automated analysis of EEG recordings from premature infants.
Formation of TiN whiskers from oxide-containing cyanide melts

It has been found that the formation of TiN whiskers by reaction of molten alkali metal (sodium, potassium) cyanide with TiN powder or with TiO2 is effected by the presence of alkali metal oxides. This has led to the successful use of reactions of molten cyanide with several sodium and potassium titanates for the formation of TiN whiskers.
A national study of AIDS and residency training: experiences, concerns, and consequences.

Objective: To examine residents' experiences in the care of patients with the acquired immunodeficiency syndrome (AIDS), and to examine factors that may influence their attitudes about such care. D...
The technology assessment and practice guidelines forum. A modified group judgment method.

This article describes a new group-judgment process, modified from the consensus development approach of the U.S. National Institutes of Health. It is called the "forum" method, a shorthand term for "technology assessment and practice guidelines forum." This approach is aimed at (a) describing the current state of knowledge of the technology under study; (b) developing practice guidelines for the use of the technology; and (c) providing information for insurers, consumers, policymakers, and others. A pilot study was conducted focusing on total parenteral nutrition. The validity of the process and of the recommendations and their acceptability were evaluated in a survey of participants and a selected group of nonparticipants. Based on the survey results, the forum method appears to be a valuable method for assessing technologies, defining their clinical role, and developing practice guidelines.
The Cardiac Denial of Impact Scale: A brief, self-report research measure

Abstract Denial is an important aspect of recovery from cardiac trauma. It has been associated with reduced anxiety, better initial physical and psychological outcomes, decreased retention of information about the illness, and decreased treatment compliance. Although interview methods for assessing denial have been available for some time, they present both psychometric and methodological difficulties that a self-report measure could alleviate. This study provides the initial psychometric evaluation of the self- report Cardiac Denial of Impact Scale. It demonstrated adequate internal consistency as well as good criterion and discriminant validity. The availability of a self-report measure of denial can simplify its assessment in both research and treatment applications.
Operationalizing diagnostic criteria for Alzheimer’s disease and other age-related cognitive impairment—Part 2

Abstract This article focuses on the effects of operational differences in case ascertainment on estimates of prevalence and incidence of cognitive impairment and/or dementia of the Alzheimer type. Experience and insights are discussed by investigators from the Framingham Heart Study, the East Boston Senior Health Project, the Chicago Health and Aging Project, the Mayo Clinic Study of Aging, the Baltimore Longitudinal Study of Aging, and the Aging, Demographics, and Memory Study. There is a general consensus that the single most important factor determining prevalence estimates of Alzheimer's disease (AD) is the severity of cognitive impairment used as a threshold to define cases. Studies that require a level of cognitive impairment in which persons are unable to provide self-care will have much lower estimates than the studies aimed at identifying persons in the earliest stages of AD. There are limited autopsy data from the aforementioned epidemiological studies to address accuracy in the diagnosis of etiological subtype, namely the specification of AD alone or in combination with other types of pathology. However, other community-based cohort studies show that many persons with mild cognitive impairment and also some persons without dementia or mild cognitive impairment meet pathological criteria for AD, thereby suggesting that the number of persons who would benefit from an effective secondary prevention intervention is probably higher than the published prevalence estimates. Improved accuracy in the clinical diagnosis of AD is anticipated with the addition of molecular and structural biomarkers in the next generation of epidemiological studies.
Oligodendroglial glycerophospholipid synthesis: Incorporation of radioactive precursors into ethanolamine glycerophospholipids by calf oligodendroglia prepared by a Percoll procedure and maintained in suspension culture

Oligodendroglia prepared from minced calf cerebral white matter by trypsinization at pH 7.4, screening, and isosmotic Percoll (polyvinylpyrolidone-coated silica gel) density gradient centrifugation survived in culture on polylysine-coated glass, extending processes and maintaining phenotypic characteristics of oligodendroglia. In the present study, ethanolamine glycerophospholipid (EGP) metabolism of the freshly isolated cells was examined during short-term suspension culture by dual label time course and substrate concentration dependence experiments with [2-3H]glycerol and either [1,2-14C]ethanolamine or L-[U-14C]serine. Rates of incorporation of 3H from the glycerol and of 14C from the ethanolamine into EGP were constant for 14 h. In medium containing 3 mM-[1,2-14C]ethanolamine and 4.8 mM-[2-3H]glycerol, rates of incorporation of 14C and 3H into diacyl glycerophosphoethanolamine (diacyl GPE) were similar. Under the same conditions, 3H specific activities of alkylacyl GPE and alkenylacyl GPE were much lower than 14C specific activities, likely as a result of the loss of tritium during synthesis of these forms of EGP via dihydroxyacetone phosphate. L-[U-14C]serine was incorporated into serine glycerophospholipid (SGP) by base exchange rather than de novo synthesis. 14C from L-[U-14C]serine also appeared in EGP after an initial lag period of several hours. Methylation of oligodendroglial EGP to choline glycerophospholipid (CGP) was not detected.
On the chemical nature of graphene edges: origin of stability and potential for magnetism in carbon materials.

Heretofore disconnected experimental observations are combined with a theoretical study to develop a model of the chemical composition of the edges of graphene sheets in both flat and curved sp2-hybridized carbon materials. It is proposed that under ambient conditions a significant fraction of the oxygen-free edge sites are neither H-terminated nor unadulterated σ free radicals, as universally assumed. The zigzag sites are carbene-like, with the triplet ground state being most common. The armchair sites are carbyne-like, with the singlet ground state being most common. This proposal is not only consistent with the key electronic properties and surface (re)activity behavior of carbons, but it can also explain the recently documented and heretofore puzzling ferromagnetic properties of some impurity-free carbon materials.
Continuous inferior mesenteric ganglion block for the control of abdominal pain.

Abstract Background and Objectives. A 71-year-old woman was referred for control of intrac-table left-sided abdominal pain and constipation caused by stage 2B rectosigmoid colon cancer. She was treated with an intravenous morphine sulfate infusion at 4 mg/h which made her drowsy and lethargic. Because the distal colon is innervated by the inferior mesenteric sympathetic ganglion, it was hypothesized that a continuous block of this ganglion would provide both pain control and increased intestinal motility. Methods. The patient was placed in a prone position, and a Tuohy needle was placed at an entry site 7 cm lateral to the L3 spinous process. The needle was advanced 2 cm anterior to the L3 vertebral body with fluoroscopic guidance. An 18-gauge indwelling catheter was placed through the needle and a continuous infusion with 0.1% bupivacaine was maintained for 4 days. Results. The patient obtained immediate pain relief and bowel motility. She remained awake and comfortable throughout the duration of therapy. She was discharged home 3 days after stopping the infusion and required a minimal amount of opioids. Conclusion. Continuous inferior mesenteric ganglion block may be an option in providing relief for pain caused by distal colon pathology.
The Primary Stone Event: A New Hypothesis Involving a Vascular Etiology

ABSTRACTPurpose: We detail a new hypothesis regarding a vascular phenomenon as the primary event in the formation of urolithiasis.Materials and Methods: A complete MEDLINE search was performed to examine the existing literature regarding the etiology of nephrolithiasis. In addition, urinary calculi were retrieved from 11 patients undergoing percutaneous nephrolithotomy and analyzed for total and esterified cholesterol content.Results: A review of the literature on stone disease revealed many factors inconsistent with the current paradigm of the initiation of nephrolithiasis. These arguments can be based and classified on epidemiological, clinical, physiological, anatomical, and molecular data. In our stone analysis free and esterified cholesterol were found in varying quantities between 0.058 and 2.258 μg/mg stone and 0.012 and 0.777 μg/mg stone, respectively. Esterified cholesterol was found to comprise 75% of total serum cholesterol. In urinary stones esterified cholesterol accounted for 14% to 16% of t...
Data development for international research—Phase I: International conflict and national characteristics

In 1986 developers and users of quantitative data in international and comparative politics organized to maintain, extend, and develop major datasets and to provide a stronger basis for coordinating data‐related activities. National Science Foundation funding established for a three‐year period Data Development for International Research. Its first phase (DDIR‐I) focused on improving datasets on both national capabilities and international conflict; and generating renewed efforts to better the data collections on internation events and international political economy. DDIR‐I's work, now virtually complete, augmented the quantity and quality of this national data resource and set the stage for another NSF‐funded project on internation event data (DDIR‐II). A final report on DDIR‐II is forthcoming in summer 1994.
Predictors of Early Engagement in Home Visitation

Predictors of engagement in mothers receiving home visitation in the first year of service was examined. Early engagement was studied in three ways: (1) length of time active in the program during the first year of service (duration), (2) number of visits received (quantity), and (3) gaps in service between visits (consistency). Examined visits received in 515 first-time mothers in a Healthy Families America (HFA) program. Parameters of engagement were investigated, and predictors of engagement were identified using demographics and the Kempe Family Stress Inventory. Inclusive of the Assessment Visit, 31.8% of mothers disengaged prior to the first month of service. Remaining active in the program was associated with being Caucasian, and increased parenting risk (mental health/substance abuse history, low social support, increased stress). Most mothers had fewer home visits than prescribed. Gaps in prescribed service were common, with 89.4% of mothers experiencing gaps between visits of 1 month, and dropping to 16.4% having gaps of 2 months. In contrast to findings from clinic-based interventions, early engagement in home visitation is associated with lower levels of functioning and acute needs. These findings add to a growing body of literature suggesting that increased adversity promotes engagement in prevention programs in general, and home visitation programs in particular. To the extent that mothers who are actively engaged in home visitation are likely to have increased psychosocial needs, curricula may require modification and augmentation to address these needs and optimize program effectiveness.
Acceptable Radiological Environmental Monitoring Programs: Nuclear Regulatory Commission Staff Rationale and Perspective

A task group of members of the US Nuclear Regulatory Commission (NRC) staff has reviewed the ration ale for radiological environmental monitoring required by NRC. The group was unable to develop a tightly knit rationale for all the elements of such a program. Two major factors led to this: (1) the large number of possible nuclide pathway combinations threatened to result in specifying lower limits of detection (LLD's) much more restrictive than considered practicable; and (2) a significant number of public reassurance-type measurement requirements always remained which did not fit a dose rationale. Therefore, the topics discussed are a mixture of requirements related to dose rationale and public reassurance. The task group concluded that radiological environmental monitoring requires a blend of two types of measurements: one type based on strict dose-related considerations and another type related to a need to make measurements which have a reassurance function. Further, whether environmental measurement data are used to directly assess the dose, to complement radioactivity release measurements, or to confirm a negative impact on the environment, there is a need for adequate quality in the data obtained to demonstrate either a correlation or lack of a correlation between facility operation and measured radioactivitymore » levels in the environment as compared with an environmental radiation dose criterion such as 25 mrem/year.« less
The simultaneous occurrence of martensitic transformation and reversion of martensite

Abstract We use a 3D elastoplastic phase-field model to study the simultaneous occurrence of martensitic transformation as well as the reversion of martensite in steels under uni-axial tension. Our results show that although martensite nucleates and grows as a single lath (variant), it reverts and splits into two independent martensite laths, due to “unfavorable” local stresses.
Protein kinase C alpha and epsilon differentially modulate hepatocyte growth factor-induced epithelial proliferation and migration.

Abstract Protein kinase C (PKC) isoenzymes require membrane translocation for physiological activation. We have recently shown that the growth factors such as epidermal growth factor and hepatocyte growth factor (HGF), but not keratinocyte growth factor (KGF), regulate PKCα activation to promote epithelial wound healing [Sharma, G.D., Ottino, P., Bazan, H.E.P., 2005. Epidermal and hepatocyte growth factors, but not keratinocyte growth factor, modulate protein kinase C alpha translocation to the plasma membrane through 15( S )-hydroxyeicosatetraenoic acid synthesis. J. Biol. Chem. 280, 7917—7924]. Protein kinase C alpha (PKCα) and protein kinase C epsilon (PKCɛ) are two differentially regulated isoenzymes. While PKCα requires Ca 2+ for its activation, PKEɛ is Ca 2+ independent. However, growth factor-induced activation of these enzymes and their specific regulation of epithelial migration and proliferation have not been explored. In the present study, we overexpressed PKCɛ fused to green fluorescent protein to examine its translocation in real-time to the plasma membrane in living human corneal epithelial cells. Stimulation with HGF and KGF demonstrated translocation of PKCɛ to the plasma membrane. Because HGF activates both PKCs, this growth factor was used to stimulate wound healing. PKCα or PKCɛ-genes were knocked down individually without affecting the basal expression of the other PKC isoforms. Gene knockdown of PKCα significantly inhibited HGF-stimulated proliferation of human corneal epithelial cells. In contrast, PKCɛ-gene-silencing severely impaired the HGF-stimulated migratory ability of human corneal epithelial cells. When migrating epithelial cells in the cornea wound bed after injury were transfected with specific PKCα- or PKCɛ-siRNA, there was a significant delay in wound healing. Corneal wound healing stimulated with HGF in similar conditions was also inhibited. On the other hand, overexpression of PKCα or PKCɛ-genes fused with green fluorescent protein in migrating corneal epithelium accelerated repair of the epithelial defect. Our findings demonstrate that PKCα and PKCɛ modulate different stages of wound healing stimulated by HGF and contribute to epithelial repair by playing selective regulatory roles in epithelial proliferation and migration, both crucial to corneal wound healing.
An investigation of electromagnetic control for formation flight applications

The use of propellant to maintain the relative orientation of multiple spacecraft in a sparse aperture telescope such as NASA's Terrestrial Planet Finder (TPF) poses several issues. These include fuel depletion, optical contamination, plume impingement, thermal emission, and vibration excitation. An alternative is to eliminate the need for propellant, except for orbit transfer, and replace it with electromagnetic control. Relative separation, relative attitude, and inertial rotation of the array can all be controlled by creating electromagnetic dipoles on each spacecraft and varying their strengths and orientations. This paper addresses some of the control issues that arise when using electromagnets to control formation geometry.
Acute cytomegalovirus hepatitis in an immunocompetent host

A 52-year-old woman presented with a 1-week history of recurrent fevers and joint pains accompanied by abdominal and low back discomfort. She has a history of hypoparathyroidism and is on calcium supplements. Physical examination revealed fever and tachycardia. The rest of the examination was normal. Laboratory tests showed newly increased transaminase activity. Serum bilirubin and prothrombin time were normal. She was admitted for evaluation of acute hepatitis. Serology for hepatitis A, B, C and HIV were negative. Her serum acetaminophen and alcohol were undetected. Abdominal imaging was normal. Cultures were sterile. Additional tests for uncommon viral hepatitis included herpes simplex virus, cytomegalovirus and Epstein-Barr virus. Liver biopsy revealed non-specific inflammation. Subsequently, cytomegalovirus serology showed an IgM positive and negative IgG titre. Cytomegalovirus DNA qualitative PCR was also positive. No antiviral medication was given. She continued to have intermittent daily fever but reported no associated symptoms. She was discharged 9 days after admission in stable condition per her request with the advice to follow-up in the clinic in 1 week. Her serum hepatic profile returned to normal and she reported no more episodes of fever. Repeated titres of cytomegalovirus serology showed seroconversion.
Hormonal Therapy for Epilepsy

In 2011, there are greater than 20 antiepileptic medications available. These medications work by modulating neuronal excitability. Reproductive hormones have been found to have a role in the pathogenesis and treatment of seizures by also altering neuronal excitability, especially in women with catamenial epilepsy. The female reproductive hormones have in general opposing effects on neuronal excitability; estrogens generally impart a proconvulsant neurophysiologic tone, whereas the progestogens have anticonvulsant effects. It follows then that fluctuations in the levels of serum progesterone and estrogen throughout a normal reproductive cycle bring about an increased or decreased risk of seizure occurrence based upon the serum estradiol/progesterone ratio. Therefore, using progesterone, its metabolite allopregnanolone, or other hormonal therapies have been explored in the treatment of patients with epilepsy.
Solubilization in Nonpolar Solvents: Influence of the Chain Length of Solvent on the Solubilization of Water by Dioctyl Sodium Sulfosuccinate

The water solubilizing capacities of the solutions of dioctyl sodium sulfosuccinate (Aerosol OT, AOT) in normal aliphatic hydrocarbon solvents from n-heptane to n-octadecane were determined as functions of the AOT concentration and temperature. The method involved adding water to the AOT solutions up to the turbidity point. The solubilizing capacity was found to be strongly dependent on the solvent chain length, increasing with decreasing chain length. For example, in octane solutions at 30° about 50 moles of water per mole AOT can be solubilized while only 5 moles can be solubilized in hexadecane solutions. The thermodynamic activity of the solubilized water was determined by a modified isopiestic method. These data indicated that the binding of water in all systems studied was essentially the same. A tentative theory based on the solvation of the micelle exterior is proposed to explain the two sets of data.
Thermal dissipative structures: Limit-cycle oscillations in high temperature fluids

Abstract Thermochemical analogues of the dissipative structures studied by Prigogine are realized in fluids that feature certain simple reaction schemes at high temperatures.
The complexity of matrix completion

Given a matrix whose entries are a mixture of numeric values and symbolic variables, the matrix completion problem is to assign values to the variables so as to maximize the resulting matrix rank. This problem has deep connections to computational complexity and numerous important algorithmic applications. Determining the complexity of this problem is a fundamental open question in computational complexity. Under different settings of parameters, the problem is variously in P, in RP, or NP-hard. We shed new light on this landscape by demonstrating a new region of NP-hard scenarios. As a special case, we obtain the first known hardness result for matrices in which each variable appears only twice.Another particular scenario that we consider is the simultaneous matrix completion problem, where one must simultaneously maximize the rank for several matrices that share variables. This problem has important applications in the field of network coding. Recent work has given a simple, greedy, deterministic algorithm for this problem, assuming that the algorithm works over a sufficiently large field. We show an exact threshold for the field size required to find a simultaneous completion efficiently. This result implies that, surprisingly, the simple greedy algorithm is optimal: finding a simultaneous completion over any smaller field is NP-hard.
Speaking out of turn: a role for silent synapses in pain.

Severe tissue or nerve injury can result in a chronic and inappropriate sensation of pain, mediated in part by the sensitization of spinal dorsal horn neurons to input from primary afferent fibers. Synaptic transmission at primary afferent synapses is mainly glutamatergic. Although a functioning excitatory synapse contains both alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors in the postsynaptic membrane, recent evidence suggests that dorsal horn neurons contain some "silent" synapses, which exhibit purely NMDA receptor-mediated evoked postsynaptic currents and do not conduct signals at resting membrane potential. Serotonin, which is released onto dorsal horn neurons by descending fibers from the rostroventral medulla, potentiates sensory transmission by activating silent synapses on those neurons, i.e., by recruiting functional AMPA receptors to the postsynaptic membrane. This phenomenon may contribute to the hyperexcitability of dorsal horn neurons seen in chronic pain conditions.
Agonistic behavior in a transplanted troop of Japanese macaques: Arashiyama west

Arashiyama A troop was transplanted from Japan to Texas, U.S.A. in February 1972 and released into a large outdoor enclosure (42 ha) in a semi-free ranging condition. Agonistic behavior was quantified during the first six months after the release. Agonistic interactions occurred at about one incident per 100 monkeys every 2 to 9 minutes. In general, peaks in frequency of agonistic interactions coincided with peaks in feeding activity. 97.5% of all incidents were of a “mild” type, and 85.7% were simple one-to-one, unidirectional interactions. “Severe” forms of agonistic behavior occurred only during the first month and then only rarely. Adult females and juveniles were initiators in about 93% of all cases. In general, the more severe the form of attack, the more pronounced was the form of submission.
Response decrement as a function of extinction or shift in reinforcement schedule

A two-phase experiment in which albino rats were trained in a straight alley provided support for viewing traditional resistance-to-extinction tests of conditioning as transfer of training paradigms.
Review of classification rules represents an opportunity, even for medicine.

The US system of classifying national security information is bloated and dysfunctional, shielding the government from the scrutiny it needs to avoid error and abusive practices. In the medical field, this secrecy has, in rare cases, enabled unethical, state-sponsored research to proceed without public knowledge. The Fundamental Classification Guidance Review that is now underway could make a difference—if it's done right.
Albuminuria reduction: the holy grail for kidney protection.

Increased urinary excretion of albumin or total protein has become firmly established as a risk predictor for progression of chronic kidney disease. Observational analyses have raised a strong hypothesis that albuminuria reduction should be a clinical treatment target. Bakris et al. report further exploration of albuminuria-lowering capabilities of intensified renin–angiotensin system inhibition in a randomized clinical trial that included patients at high cardiovascular risk, most of whom appeared to have diabetic kidney disease.
Interaction of polyvinylpyrrolidone and iodine

A nonsolvent preparation of the polyvinylpyrrolidone (PVP) complex provides new insight into the nature of the polymer-iodine interaction. The preparation is obtained by simply mixing PVP with crystalline iodine and is of interest because it provides a system in which no interfering ions are present and only one type of iodine is initially present. The iodine is shown to undergo hydrolysis with moisture in the polymer to give iodide and hypoiodite. The ionic forms of iodine appear to associate with the molecular iodine, resulting in the final stable PVP-iodine complex.
Effect of Local Flange Damage on the Stability of Steel Columns

The stability of steel columns that have suffered localized damage is investigated through analytical and computational means. An analytical model based on the Rayleigh-Ritz technique is used in conjunction with detailed finite element models to study the effect of damage extent and location on column load carrying capacity. Analytical and simulation results show a severe reduction in column axial resistance in the presence of localized flange loss.
The Work Costs of Earning Food as a Determinant of Patch Leaving

Foraging theorists have long emphasized the role of the energy (work) costs of food items on foraging behavior. However, few experiments have measured this variable or demonstrated that animals are indeed sensitive to work costs. Experiment 1 assessed whether rats (LongEvans) can use the work costs of food to determine whether a food patch is exhausted. Rats performed a fixed amount of work for each food item (fixed-work [FW] schedule), but food was withheld unpredictably to simulate sudden patch depletion. It was found that rats left patches only when the work costs of unsuccessful searches (giving-up work) exceeded the prevailing work costs of food. The time and response costs of unsuccessful food searches (giving-up time and giving-up responses) were not predictive of patch leaving. Experiment 2 showed how rats regulated work in this paradigm by examining the role of exteroceptive stimuli connected with fulfilling the FW schedule. For the majority of predators, food resources are not uniformly distributed within the environment but occur in patches (e.g., a clump of berries for a bird or a zebra carcass for a lion). As predators feed, patches usually deplete. Patch depletion may be gradual, for example, when successive food items become increasingly more costly to obtain; or, it may be sudden, for instance, when the final food item in the patch is consumed. Thus, one problem faced by predators is when to leave the current patch to travel to a new patch. In an environment in which patch depletion occurs gradually, and in a sense predictably, patch leaving should be based on the instantaneous rate of increase in food cost relative to the cost of food elsewhere in the environment. This idea has been formalized in the marginal value theorem (Chamov, 1976). However, in an environment in which patch depletion occurs suddenly, it is reasonable to expect that predators will abandon the patch as soon as the depletion can be identified. Thus, the problem faced by foragers in this type of foraging environment is how to discriminate depletion from nondepletion. It has been argued that predators use the costs of searches
Reverse hydrophobic effects relieved by amino-acid substitutions at a protein surface

It is rare for amino-acid substitutions on the surface of proteins to have large stabilizing or destabilizing effects. Nevertheless, one substitution of this type, the Tyr 26----Cys mutation in lambda Cro, increases the melting temperature of the protein by 11 degrees C and the stability by 2.2 kcal mol-1. Here we show that the stability of Cro can be increased by many different amino-acid substitutions at position 26, with increasing stability showing a good correlation with decreasing side-chain hydrophobicity. As Tyr 26 is hyper-exposed to solvent in the Cro crystal structure, we suggest that wild-type and variant proteins with other hydrophobic side chains at position 26 are destabilized as a result of a reverse hydrophobic effect caused by the side chain being more exposed to solvent in the native than in the denatured state.
Chemical weathering and Rb-Sr whole rock ages

Abstract Weathered whole rock samples of five lithic units from Maine, Virginia, North Carolina and South Carolina were analyzed to evaluate the effect of chemical weathering on the Rb-Sr ages of the original rocks. Major element and turbidity analyses, as well as standard X-ray diffraction and petrographic studies were made on selected samples. All weathered granitic rocks are friable; several are almost saprolites. Volcanic rocks are powdery or are pitted as a result of the weathering of plagioclase phenocrysts. The weathering profiles studied all are young relative to the age of the unaltered rock. Considering the extent of weathering, however, ages of the weathered samples are remarkably close to the published ages for unaltered samples of the same units. Weathered samples have ages ranging from essentially the same as fresh samples to no more than 20% younger than the age obtained from the fresh samples. In one profile, we have attempted to quantify the extent of weathering: there is a positive correlation between our measure of the degree of weathering and per cent ‘lowering’ of the age. Weathering of plagioclase apparently has little effect on whole rock ages; ages are lowered significantly only where biotite and K-feldspar have undergone considerable alteration.
Caregivers' Knowledge and Perceptions of Preventing Childhood Lead Poisoning

Philadelphia is considered a high-risk area for lead poisoning. The Philadelphia Department of Public Health conducts education and outreach to screen children and promote prevention. Prior to this study there were no systematic data on the community's knowledge and perceptions of lead poisoning prevention. A 32-item questionnaire was developed to assess knowledge and perceptions of family caregivers of children younger than age 8. The survey was interviewer administered in pediatric clinics in two geographic areas of the city with documented severe and moderate lead poisoning rates. Eighty family caregivers were interviewed while waiting to see the pediatrician. Caregivers in the sample were connected to a health care system and resided in areas where lead community outreach was concentrated. Nevertheless, results suggest that even caregivers of children in high-risk areas do not mention lead poisoning as a health concern. About 61% of the sample identified eating paint chips as a cause of lead poisoning, whereas only 15% identified lead paint dust as a source of lead poisoning. Approximately 49% of the caregivers reported that they "never" or only "sometimes" perform recommended prevention activities. The Philadelphia Department of Public Health used these findings to review and modify education and outreach to prevent lead poisoning.
Mixed layer transformation for the North Atlantic for 1990–2000

[1] The buoyancy balance between two outcropping isopycnals leads to diagnostics for quantifying water mass formation rates between them due to air-sea buoyancy fluxes [Walin, 1982]. The surface air-sea transformation gets modified by mixed layer processes so that the net formation rate below the winter mixed layer depth is different from that given by surface air-sea fluxes alone. Here we estimate the role of time dependence and mixed layer deepening to quantify the water mass transformation due to mixed layer entrainment fluxes. We focus on the mixed layer transformation in the North Atlantic for 1990–2000 during the World Ocean Circulation Experiment period, using both entrainment parameters and isopycnal geometry. The water mass transformation due to mixed layer entrainment is calculated using a large number of gridded one-dimensional mixed layer models forced by National Centers for Environmental Prediction (NCEP) reanalysis air-sea fluxes (daily/6 hourly) to calculate the local entrainment parameters; Reynolds sea surface temperature and Levitus monthly salinity data determine the isopycnal geometry. To get a closed annual cycle in the mixed layer depth, any net annual heat flux is ascribed to advective processes. These are included in the annual mean, leaving any synoptic forcing in the NCEP forcing unperturbed. In general, the mixed layer transformation opposes air-sea interaction, with amplitudes of (1.3 Sv) in the equatorial region (without equatorial upwelling contribution) and (0.5 Sv) in the overflow region. Mean cross-isopycnal volume fluxes are O(1 Sv), with considerable interannual variability. These estimates of water mass formation due to mixed layer processes are sensitive to synoptic frequencies, but not to climatological mean air-sea fluxes, and are within the imposed noise levels for inverse box models of the North Atlantic.
Higgs Boson Production via $Z$, $W$ Bosons and Toponium in the $E(6)$ Superstring Model

We examine the production of light Higgs bosons associated with electroweak symmetry-breaking in an E6 superstring model in Z→HZ* decays, in e+e− annihilation and in toponium decays. We find that the couplings of the lightest scalar Higgs boson in these models are very similar to those of the standard Higgs boson unless the pseudoscalar P0 in the model has mass ≤Mz. Possible new modes for Higgs boson production not found in the standard model include or and or (H+H−), where is the second lightest scalar. We give simple analytic expressions for the Higgs boson masses and mixing angles in the limit that the extra Z′ gauge boson is heavy which clearly shows the production mechanisms that are favored for a given set of model parameters. The lower bound on the mass of the charged Higgs boson associated with the electroweak symmetry breaking is 53 GeV, independent of the Z′ boson mass or mixing; this bound is realized only for very small and P0 masses. Toponium decays to and H+H− may exist at up to the per cent level for some model parameters. The dominant decay mode for could be , if kinematically allowed, while the principal decays for could be or .
Uranium Content of Some Stone Meteorites and their Pu–Xe Decay Interval

Kuroda and Reynolds have recently discussed whether or not the Pu–Xe and I–Xe decay intervals of stone meteorites are concordant, and the implications of this question to models of galactic nucleosynthesis. Kuroda states1,2 that they are concordant, while Reynolds3,4 believes the question is still open. Kuroda notes that the 136fXe/U ratios are excessively high in two eucrites, Petersburg and Moore County, indicating Pu–Xe decay intervals for these two meteorites which are not concordant with their I–Xe decay intervals beyond his acceptable limits of error (± 30 per cent). Using his average eucrite uranium abundance of 130 p.p.b. for these two meteorites, instead of their measured abundances of 100 and 40 p.p.b. respectively, he brings the decay intervals to near concordancy, arguing that the measured uranium abundances may well be wrong because of tellurium interferences with the neutron activation analysis. It therefore becomes a critical test of Kuroda's model to measure the uranium in either of these meteorites by a different technique. In particular, the difference between the measured and predicted U abundances in Moore County is significant.
A Note on the Reliability of Ranked Items

Instruments may be designed to use either Likert-type items (ratings) or ranks to obtain priority rankings of items. Models commonly used in generalizability theory (GT) provide a basis for assessing the reliability of item measurements based on ratings. However, these commonly used models do not apply when respondents are required to rank a set of items. Unlike ratings, ranks force subject effects to zero. Furthermore, ranks violate independence assumptions, and the dependence between ranks assigned to different items affects the standard error of item mean differences and, consequently, the reliability of the item comparisons. A GT analysis for ranked items is presented and used to derive standard errors for differences between item means as well as an item measurement reliability coefficient. This analysis uses a linear model that is not typically used in GT analyses but that models those features unique to ranks.
A Disturbance Index for Karst Environments

Karst environments, unique from other environments, require their own disturbance index. Karst resources are increasingly disturbed by a variety of processes related to social, physical, and economic factors. Recent studies have begun to qualify and quantify these disturbances, yet their focus has been limited to one or two factors such as biotic, geomorphic, or economic impacts. A more holistic approach, addressing economic, scientific, and cultural factors, is needed, to effectively assess the threats to karst areas. Currently, there is no efficient method to measure, compare, and contrast the disturbance of karst environments. We propose a hierarchal and standardized environmental disturbance index as a tool to measure regional impacts and highlight the areas of the karst system that require more protection or study. Addressed categories of disturbance include cultural, biotic, atmospheric, hydrological, and geomorphologic impacts.
Optical time-domain analog pattern correlator for high-speed real-time image recognition

The speed of image processing is limited by image acquisition circuitry. While optical pattern recognition techniques can reduce the computational burden on digital image processing, their image correlation rates are typically low due to the use of spatial optical elements. Here we report a method that overcomes this limitation and enables fast real-time analog image recognition at a record correlation rate of 36.7 MHz—1000 times higher rates than conventional methods. This technique seamlessly performs image acquisition, correlation, and signal integration all optically in the time domain before analog-to-digital conversion by virtue of optical space-to-time mapping.
Space Weather and Satellite Engineering: An Interview With Michael Bodeau

Michael Bodeau is a technical fellow at Northrop Grumman. Over his career, which has included positions at TRW, Hughes, and Boeing, he has designed telecommunications and scientific satellites for government and commercial operators and has studied the effects of space weather on satellites. In this interview, Bodeau describes how satellite engineers create “building codes” to help them design satellites that can withstand space weather events.