cssi/SciSciGPT-SciSciNet huggingface dataset:
Mexican psychology the past 50 years and opportunities for the future

La colaboracion y el intercambio entre psicologos mexicanos y los de la Universidad de Texas empezaron con el Tercer Congreso Interamericano de Psicologia, que se llevo a cabo en Austin, Texas, en 1955 y han continuado hasta el presente bajo el liderazgo del Dr. Rogelio Diaz Guerrero. Desde 1959 y hasta 1975, mas de 400 estudiantes avanzados de psicologia mexicanos participaron en una serie de seminarios en la Universidad de Texas y se familiarizaron con la psicologia estadounidense moderna. Muchos de ellos posteriormente se convirtieron en profesores de varias universidades mexicanas, lo cual resulto en el rapido crecimiento de la psicologia en Mexico. Mientras que la psicologia academica en Mexico se encuentra hoy dia entre las mejores de las Americas, la practica profesional de la psicologia en Mexico aun tiene un largo camino por recorrer para estar a la par con la psicologia profesional en los Estados Unidos, Canada y Europa. Es importante que los miembros de la Sociedad Mexicana de Psicologia ejerzan su liderazgo para el avance de la psicologia como una profesion, en colaboracion con las agencias gubernamentales apropiadas
Preventing developmental delays: is developmental screening sufficient?

Developmental screening, a secondary form of prevention, is designed to facilitate early identification and treatment of children in whom a developmental problem has been diagnosed. Ideally, this is accomplished through the administration of a quick, simple, economical procedure that is designed to identify children having a high probability of being delayed. Unfortunately, no single, brief developmental screening test exists that has equal accuracy in identifying the wide gamut of developmental problems in areas such as cognition, language, speech, motor, and social development. In addition, the child9s changing development over time limits the predictive accuracy of any such test. Despite these limitations, developmental screening, like a growth measurement, has value as an aide in developmental surveillance, because it enables its user to combine its results with those of parent concerns, child observations, immunizations, and anticipatory guidance to promote the child9s development. This process, rather than waiting for the child to be deviant, is a primary prevention approach that aims to assure that every child receiving such surveillance develops to his or her maximum potential. The DENVER II is designed to assist in this program.
The Status Quo Bias and Contract Default Rules

The rich law and economics literature on contract default rules - that is, terms that govern relationships between contracting parties only if those parties do not explicitly agree to other terms - presumes that the legal system's choice of default rules will not affect individual negotiators' underlying preferences for contract terms. Judgment and decision making literature on the "status quo bias" suggests that if bargainers perceive default terms as part of the status quo they will prefer the substantive content of those terms more than they would if other terms were the legal defaults. This paper presents a study designed to test this hypothesis. 151 law students were asked to provide advice to a client in a number of hypothetical contract negotiation scenarios with the content of the default terms manipulated between experimental groups. The results suggest that the choice of legal default terms affects not only what terms contracting parties will agree upon but also what terms they actually prefer. The paper presents the experimental results, considers various theoretical explanations for the results, and suggests how the results should impact legal scholars' analysis of what contract default rules are optimally efficient.
Antenna subset selection in distributed multiple-radar architectures: A knapsack problem formulation

In this paper, a performance driven resource allocation scheme for target localization in multiple radar systems is proposed and evaluated. An optimal subset of active antennas of predetermined size, K, is selected such that the localization mean-square error (MSE) is minimized. The problem is formulated in a combinatorial optimization framework as a knapsack problem (KP). The Cramer-Rao bound (CRB) is used as a performance metric. Cost parameters, representing operational cost or any other utilization constraints, are associated with each of the antennas. These are incorporated into the KP formulation, integrating decision making factors in the selection process. Antenna subset selection is implemented through an approximation algorithm, by successively selecting antennas so as to maximize the temporal Fisher information matrix (FIM) for a given subset size. The proposed approximation algorithm offers considerable reduction in computational complexity when compared with exhaustive search, supporting distributive processing and low performance loss.
Safe Feature Elimination for the LASSO and Sparse Supervised Learning Problems

We describe a fast method to eliminate features (variables) in l1 -penalized least-square regression (or LASSO) problems. The elimination of features leads to a potentially substantial reduction in running time, specially for large values of the penalty parameter. Our method is not heuristic: it only eliminates features that are guaranteed to be absent after solving the LASSO problem. The feature elimination step is easy to parallelize and can test each feature for elimination independently. Moreover, the computational effort of our method is negligible compared to that of solving the LASSO problem - roughly it is the same as single gradient step. Our method extends the scope of existing LASSO algorithms to treat larger data sets, previously out of their reach. We show how our method can be extended to general l1 -penalized convex problems and present preliminary results for the Sparse Support Vector Machine and Logistic Regression problems.
The role of vdW interactions in coverage dependent adsorption energies of atomic adsorbates on Pt(111) and Pd(111)

Abstract Adsorption, a fundamental process in heterogeneous catalysis is known to be dependent on the adsorbate–adsorbate and surface–adsorbate bonds. van der Waals (vdW) interactions are one of the types of interactions that have not been examined thoroughly as a function of adsorbate coverage. In this work we quantify the vdW interactions for atomic adsorbates on late transition metal surfaces, and determine how these long range forces affect the coverage dependent adsorption energies. We calculate the adsorption energies of carbon, nitrogen, oxygen, sulfur, fluorine, bromine and chlorine species on Pt(111) and Pd(111) at coverages ranging from 1 4 to 1 ML using the BEEF-vdW functional. We observe that adsorption energies remain coverage dependent, and this coverage dependence is shown to be statistically significant. vdW interactions are found to be coverage dependent, but more significantly, they are found to be dependent on molecular properties such as adsorbate size, and consequently, correlate with the adsorbate effective nuclear charge. We observe that these interactions account for a reduction in the binding energy of the system, due to the destabilizing attractive interactions between the adsorbates which weaken its bond with the surface.
The vibrational relaxation of I2 by H2 in a supersonic jet

Abstract The vibrational relaxation of I2 by H2 has been studied in a supersonic free jet. It was observed that the addition of 5% H2 to the helium carrier gas greatly reduces the concentration of X 1Σ+g(ν″ = 1) I2 in the jet as compared to the concentration in a pure helium carrier. From this observation we have determined that the average vibrational relaxation cross sections of H2 is 7.1 times as large as that of helium. Since the average vibrational relaxation cross section of deuterium is at least as large as that of hydrogen, the mechanism responsible for this phenomenon appears not to be dominated by mass effects.
Impact of the Diagnostic-Related Group Prospective Payment Systexn on the Outcome and Quality of Care of Elderly Patients Hospitalized with Pneumonia

In order to determine whether the institution of the Medicare prospective payment system has led to poorer outcome and quality of care for patients hos pitalized with pneumonia at the Hershey Medical Center, a critical review of elderly pneumonia pa tients was performed for two time periods. The first time period was July 1981 through June 1982 (pre- diagnostic-related group era). The second time period was July 1984 through June 1985 (diagnostic-re lated group era). There were no significant differ ences between these two groups in terms of age, se verity of illness, and mean length of stay. The number of deaths was virtually identical for each group (ap proximately 27% mortality overall). We were unable to show any differences in the quality of care by a structured process of care review. Thus, we conclude that the prospective payment system has not had a negative impact on outcome or quality of patient care in patients hospitalized with pneumonia at this uni versity hospital.
Functions of Antibodies

Antibodies can impact pathogens in the presence or in the absence of effector cells or effector molecules such as complement, and experiments can often sort out with precision the mechanisms by which an antibody inhibits a pathogen in vitro. In addition, in vivo models, particularly those engineered to knock in or knock out effector cells or effector molecules, are excellent tools for understanding antibody functions. However, it is highly likely that multiple antibody functions occur simultaneously or sequentially in the presence of an infecting organism in vivo. The most critical incentive for measuring antibody functions is to provide a basis for vaccine development and for the development of therapeutic antibodies. In this respect, some functions, such as virus neutralization, serve to inhibit the acquisition of a pathogen or limit its pathogenesis. However, antibodies can also enhance replication or contribute to pathogenesis. This review emphasizes those antibody functions that are potentially beneficial to the host. In addition, this review will focus on the effects of antibodies on organisms themselves, rather than on the toxins the organisms may produce.
Non-genomic actions of thyroid hormone in brain development

Thyroid hormone (TH) is essential for neuronal migration and synaptogenesis in the developing brain. Assembly of neuronal circuits depends on guidance cues provided by the extracellular matrix. These cues are interpreted by the migrating neuron and its growing neurites through transmembrane signaling proteins anchored in place by the actin cytoskeleton. One of the best examples of a non-genomic action of thyroid hormone is its dynamic regulation of the number and quantity of actin fibers in astrocytes. Thyroxine (T4) and its transcriptionally inactive metabolite, 3',5',3-triiodothyronine (reverse T3) are responsible for modulating microfilament organization, while the transcriptional activator, 3',3,5-triiodothyronine (T3) is inert. The biological consequence of the loss of the actin filaments in astrocytes is the inability of the cell to anchor laminin, to its cell surface, and the loss of this key guidance molecule interrupts neurite pathfinding and neuronal migration. These data provide the essentials to construct a physiological pathway where TH-dependent regulation of the polymerization state of actin in the astrocyte and the developing neuron modulates the production and recognition of guidance cues--cues that if disrupted lead to abnormal neuronal migration and neuronal process formation--and lead to the morphological deficits observed in the cretinous brain.
Critical skills assessment for the treatment of geriatric patients: Geriatric Dentistry

Summary This paper reports the results of a needs assessment survey conducted to identify education objectives for the dentist geriatric fellowship program initiated by the Veterans Administration in 1982. A cascading sample design was used to identify 82 persons recognized as experts in geriatric dentistry. Each was asked to list five knowledge, skill, and attitudinal objectives considered most crucial for comptence of the geriatric dentist. The 30 major critical competencies cited and their relative frequencies are presented as a kind of definition of the competent geriatric dentist and a guide to planning and evaluation of geriatric dentistry programs
On the developmental regulation of acetylcholine receptor mobility in the Xenopus embryonic muscle membrane.

We have investigated the possible mechanisms underlying a developmental decrease in acetylcholine (ACh) receptor mobility in the membrane of cultured, spherical, mononucleate Xenopus embryonic muscle cells (myoballs) utilizing the method of in situ electrophoresis. We observed that between 1 and 4 days in culture, a substantial redistribution of ACh receptors can be induced by the externally applied electric field which resulted in highly asymmetrical ACh sensitivities at the cathode- and anode-facing poles of the cell. Between 5 and 8 days in culture, the extent of ACh receptor redistribution induced by the field declined to a lower level. Pretreatment with cytoskeletal disrupting agents or with a disulfide bond reducing agent before in situ electrophoresis had no effect on 2-day-old cultures but enhanced receptor mobility in 6-day-old cultures. Pretreatment with Ca2+-Mg2+-free saline (CMF), which releases cell coat material in other systems, substantially increased receptor mobility when tested on days 2, 6, and 8. On day 6, pretreatment with CMF containing cytochalasin B (CB) and colchicine produced an even greater increase in receptor mobility as compared to treatment with CB and colchicine alone. Our findings suggest that the developmental decrease in ACh receptor mobility is accounted for by at least two different mechanisms: (1) An early-developing, CMF-sensitive restriction possibly mediated by the cell coat; (2) a later-developing restriction possibly dependent on cytoskeletal elements and disulfide linkages. The recovery of high ACh receptor mobility in the older cultures following some of the pretreatments indicates that factors determining ACh receptor mobility can arise from molecular interactions external to the lipid bilayer.
Anaerobic Metabolism of Biodiesel and Its Impact on Metal Corrosion

Biodiesels have gained widespread acceptance because they are domestically produced carbon-neutral fuels that ultimately decrease greenhouse gas emissions and reduce dependence on fossil imports. While they are chemically and physically stable fuels, their susceptibility to biological degradation in the absence of oxygen is underexplored. We incubated five anaerobic inocula with biodiesel. The microorganisms originated from fresh and marine environments with differing histories of exposure to hydrocarbons, biodiesel, and oxygen. All inocula were able to biodegrade biodiesel within 1 month. Biodiesel metabolism accelerated the rate of both sulfate reduction and methanogenesis above biodiesel-unamended controls. Metabolite profiling indicated that the methyl esters of biodiesel were readily hydrolyzed to the corresponding suite of fatty acids, and the latter were also metabolized. Electrochemical/corrosion experiments showed that the anaerobic microbial metabolism of biodiesel in coastal seawater samples accelerated the rate of pitting corrosion in carbon steel. The susceptibility of biodiesel to anaerobic biodegradation and its propensity to stimulate biocorrosion suggest caution when integrating this alternate fuel with the existing infrastructure.
Increases in activities of aminoacyl-tRNA synthetases during cold-treatment of dormant pear embryo

Summary Aminoacyl-tRNA synthetases from a pH 5 enzyme fraction from dormant or non-dormant pear embryos were studied by the pyrophosphate exchange assay. Synthetases from dry embryos exchanged 18.6 n mol/min/mg protein. This value was slightly increased by the moist treatment, however a greater increase was obtained by cold-treatment. The activity of individual synthetases was generally higher after cold-treatment. The rate of pyrophosphate exchange was enhanced by kinetin or gibberellic acid treatment of dormant embryos and additional enhancement was observed when both hormones were used in combination. Abscisic acid inhibited synthetase activity in non-dormant embryos. The presence of 6-methylpurine during a 5 day cold-treatment resulted in a 50% decrease in enzyme activity compared to the control.
Post-integration in the recall of grammatical and ungrammatical word sequences

This experiment investigated the possibility of a post-integration mechanism in recall, i.e., whether later occurring items could organize or influence the recall of prior items. Assuming that the noun (in the final position) is the major organizing element in a noun phrase, it was predicted that prior modifiers would be better recalled if the phrase ended with a noun than if the noun was replaced by an adjective, in one condition, or a preposition or conjunction, in another condition. The over-all results supported the hypothesis. Further, no significant difference was found between the latter two conditions. The results were considered favorable to a post-integration interpretation.
Chromatographic alteration of a nonionic surfactant mixture during transport in dense nonaqueous phase liquid contaminated sediment

Chromatographic alteration of a nonionic surfactant mixture during transport through DNAPL-contaminated aquifer sediment may occur due to differential loss of oligomers to sediment and to dense nonaqueous phase liquid (DNAPL). These losses may significantly alter the solubilizing properties of the mixture, which is a concern when the surfactant mixture is applied for the purpose of DNAPL solubilization. This study examined a nonionic surfactant mixture, which was characterized in terms of oligomer distribution within the mixture and the ability of the mixture to solubilize residual DNAPL. Three sediment-packed columns were connected in series to represent upgradient, residual, and down-gradient zones, respectively, of a DNAPL-contaminated site. In the up-gradient column, greater retardation of high ethoxylate (EO) content oligomers was observed relative to low EO content oligomers, due to preferential sorption of high EO content oligomers by the sediment. In the residual-zone column, much greater retardation of low EO content oligomers relative to high EO content oligomers occurred, due to preferential sorption of low EO content oligomers to residual DNAPL. In the down-gradient column, retardation of only the high EO content oligomers was observed, due to lack of sorption of low EO content oligomers to sediment. Surfactant losses to sediment and DNAPL delayedmore » the solubilization of DNAPL due to reduction of surfactant concentration and overall increased polarity of the surfactant mixture. Increased solution flow rate decreased surfactant sorption but resulted in an overall decrease in the mass of DNAPL solubilized due to kinetic limitations in DNAPL solubilization.« less
Uses of theory in the design of sliding electrical contacts

The broadly based use of theory for understanding, and hence improving, electrical contacts is considered. The author discusses such uses in four areas: (i) studies of monolithic metal-graphite brushes for determining their operating limits; (ii) development of high-performance metal fiber brushes based on theoretical considerations; (iii) developing a computer program for calculating contact spot temperatures, being the principal determinant of top brush performance; and (iv) studies of microscopic processes at a-spots including adsorbed layers, with the aim of optimizing the operating conditions of sliding contacts. >
Biological control of aquatic vegetation using grass carp: simulation of alternative strategies

We describe the development and use of a simulation model to evaluate alternative aquatic vegetation management strategies that involve both stocking and harvesting of grass carp (Ctenopharyngodon idella Val.) under a variety of environmental conditions characteristic of the southern United States. The model consists of three submodels representing (1) biomass dynamics of the vegetation, (2) grass carp bioenergetics and growth, and (3) management operations. The model accurately simulated biomass dynamics of aquatic vegetation under various intensities of grass carp grazing in Texas ponds, and also simulated grass carp growth rates comparable to those reported in the literature. Simulation of alternative management strategies suggested that a major disadvantage of using grass carp as a biological control agent, i.e. the complete elimination of aquatic vegetation and concurrent destruction of habitat for sport fishes, can be avoided through sequential harvesting and restocking.
Identification of a C-Terminal Regulatory Motif in Hepatitis C Virus RNA-Dependent RNA Polymerase: Structural and Biochemical Analysis

The NS5B RNA-dependent RNA polymerase encoded by the hepatitis C virus (HCV) is a key component of the viral replicase. Reported here is the three-dimensional structure of HCV NS5B polymerase, with the highlight on its C-terminal folding, determined by X-ray crystallography at 2.1-A resolution. Structural analysis revealed that a stretch of C-terminal residues of HCV NS5B inserted into the putative RNA binding cleft, where they formed a hydrophobic pocket and interacted with several important structural elements. This region was found to be conserved and unique to the RNA polymerases encoded by HCV and related viruses. Through biochemical analyses, we confirmed that this region interfered with the binding of HCV NS5B to RNA. Deletion of this fragment from HCV NS5B enhanced the RNA synthesis rate up to ∼50-fold. These results provide not only direct experimental insights into the role of the C-terminal tail of HCV NS5B polymerase but also a working model for the RNA synthesis mechanism employed by HCV and related viruses.
Using a strained flame model to collapse dynamic mode data in a swirl-stabilized syngas combustor

Abstract The combustion dynamics of carbon monoxide–hydrogen mixtures (syngas) are investigated in an atmospheric pressure swirl-stabilized combustor. Numerical simulations of strained laminar flames are used to determine the consumption speed of syngas mixtures as a function of fuel composition, equivalence ratio and strain rate. Pressure measurements and high-speed video from the experiments are used to identify several distinct operating modes. Across the range of fuel mixtures and equivalence ratios tested, three distinct dynamic regimes are observed. Near the lean blowout limit, stable helical flames anchored within the central recirculation zone are observed. In this regime, the flame appears to wrap around a precessing vortex core. At intermediate equivalence ratios, low-frequency, weakly oscillating quasi-stable flames anchored at the swirler centerbody are observed. At higher equivalence ratios, the flame becomes unstable and oscillates at higher frequencies coupled with the combustor acoustics. The flame under these conditions is impacted by vortex formation in the outer recirculation zone. Higher hydrogen concentration in the fuel reduces the equivalence ratios at which the transitions between regimes are observed. We demonstrate that the numerical results can be used to collapse the gain curves describing the transitions among the three dynamic modes into a function of strained flame speed alone, rather than a function dependent on both equivalence ratio and fuel composition.
Second site reversion of a mutation near the amino terminus of the HIV-1 capsid protein.

During HIV-1 morphogenesis, the precursor Gag protein is processed to release capsid (CA) proteins that form the mature virus core. In this process, the CA proteins assemble a lattice in which N-terminal domain (NTD) helices 1–3 are critical for multimer formation. Mature core assembly requires refolding of the N-terminus of CA into a β-hairpin, but the precise contribution of the hairpin core morphogenesis is unclear. We found that mutations at isoleucine 15 (I15), between the β-hairpin and NTD helix 1 are incompatible with proper mature core assembly. However, a compensatory mutation of histidine 12 in the β-hairpin to a tyrosine was selected by long term passage of an I15 mutant virus in T cells. The tyrosine does not interact directly with residue 15, but with NTD helix 3, supporting a model in which β-hairpin folding serves to align helix 3 for mature NTD multimerization.
An Approximate Analytical Model for the Separation of a Sphere From a Flat in the Presence of a Liquid

An approximate analytical model is proposed to describe the process of separating a sphere from a flat in the presence of a Newtonian liquid, under conditions of constant force. The model is based on consideration of the effects of sphere inertia in characterizing the critical point of separation-namely, that there is a sudden onset of significant sphere acceleration. Good agreement is found between the predictions of the analytical model with those of a full numerical simulation.
Efficacy and quality of ibuprofen and acetaminophen plus codeine analgesia1

Ibuprofen, 400 mg, was compared with 300 mg acetaminophen plus 30 mg of codeine and placebo in 120 post-orthopedic surgery patients with moderate to severe pain. The study was designed as a double-blind, single-dose, parallel-group analgesic efficacy assay. Estimates of analgesia were obtained up to 6 h using categorical and visual analog measures of pain intensity and pain relief. Estimates of selected elements of mood and of sensory and affective components of pain were obtained at 0 and 2 h using contrasting mood word/phrase pairs and a portion of the McGill Pain Questionnaire, respectively. Drugs were distinguishable from placebo in total analgesic effect, and ibuprofen was more effective than acetaminophen plus codeine, especially in terms of duration. While peak effects were comparable, they occurred 1 h later following ibuprofen. Differences among treatments were more discernible using visual analog measures. Side effects were minimal. Ibuprofen provided greater improvement in selected elements of mood than acetaminophen plus codeine at comparable levels of pain relief. While decreases in the sensory component of pain were most highly associated with pain relief provided by ibuprofen, decreases in the affective component were most highly associated with pain relief following acetaminophen plus codeine. These latter results indicate that mood assessment and the discrimination between sensory and affective components of pain could be particularly useful within analgesic drug assays, especially when comparing analgesics of differing pharmacologic class and when comparing the results of such assays in pain syndromes characterized by differing pain quality.
Stability of Prednisolone in an Organic Vehicle

Prednisolone (0.7042 Gm.) was dissolved in 35 ml. of a vehicle (CMP) composed of 50 percent camphor, 25 percent m -cresyl acetate, and 25 percent p -chlorophenol, a mixture used in dentistry as a pulp-capping agent to reduce sensitivity in dental restorations. This preparation was assayed by the blue tetrazolium reaction and compared with an identically treated sample of USP reference standard prednisolone. The prednisolone–CMP mixture was then incubated at 60° with aliquots collected for assay at intervals of 24 hr., 5 days, 1 week, 2 weeks, and 6 weeks. At the end of 2 weeks of incubation, 99.3 percent of the prednisolone still remained; after 6 weeks' incubation, the prednisolone concentration had dropped to 72.4 percent of the preincubation concentration. Compared to literature values on the thermal stability of aqueous preparations of prednisolone, these results indicate that prednisolone in CMP is quite stable.
Serum glycoprotein synthesis by the fetal rat

Abstract 1. 1. The 16–21-day gestation fetal rat was shown to be capable of synthesizing the carbohydrate portion of its serum glycoproteins. 2. 2. The pattern of carbohydrate labeling of fetal rat serum glycoproteins following the injection of radioactivity labeled glucosamine is similar to that of the normal adult rat. Approx. 80% of the maternal protein-bound radioactivity and 90% of the fetal protein-bound radioactivity is recovered as glucosamine and the remainder as sialic acid.
Iron bioavailability from super enriched breads in weanling mice

Bread made from starch, unenriched, enriched, super-enriched and whole wheat flour was fed to male weanling mice for 21 days to explore the effect on iron utilization using liver, blood iron status and iron balance as parameters of evaluation. The results indicated that iron retentions, blood hemoglobin and hematocrit levels, and liver iron concentration numerically tended to be greater in mice fed super enriched bread than in mice fed the enriched bread but, for most parameters, these differences were not found to be statistically significant. Iron absorption from whole wheat bread was significantly poorer than the super enriched or enriched white wheat bread rations.
Lack of effect of choline and narcotic antagonists upon apomorphine discrimination

Rats were trained to discriminate between the stimulus properties of intraperitoneal 0.16 mg/kg apomorphine and saline in a two-lever, food-motivated operant task. Subjects were then injected with either 79 mg choline chloride, 0.02 mg/kg haloperidol, 10 mg/kg naloxone or 10 mg/kg naltrexone prior to apomorphine or saline discriminative testing. Only haloperidol pretreatment was observed to significantly alter the rats' ability to discriminate apomorphine. The results are discussed in relation to the possible mechanism(s) of action of narcotic antagonist and cholinomimetic drug effects upon dopaminergically mediated behaviors.
Short-term effects of pine straw raking on plant species richness and composition of longleaf pine communities

Abstract Pine straw is commonly used as landscaping material throughout the southeastern USA, but little is known regarding the effects of raking and removal of straw in natural longleaf pine ( Pinus palustris ) communities. In a 2–year experiment, we tested the effects of community type (scrub oak, dry savanna, and mesic savanna) and number of mechanized rakings (0–4 times over a 2-year period) on species richness and floristic composition of vascular plants at spatial scales of 1 and 100 m 2 . Multiple rakings caused richness to decline in the scrub oak community (1 m 2 ) and to increase in the more heavily-vegetated mesic savanna (1 and 100 m 2 ). Changes in richness were not proportional to the number of rakings, perhaps because (1) vegetation injury was minimal, (2) regrowth was possible owing to a largely perennial flora, and (3) the first litter removal removed the greatest amount of vegetation. In the mesic savanna, the only significant decline in richness, relative to initial values, occurred immediately after the first raking. Some seasonal variations were observed in species richness and in the quantity of vegetation removed by raking. Although raking may selectively injure shrubs and wiregrass, raking did not allow the introduction of non-native plants and generally had little effect on floristic composition.
Maturation-Induced Cloaking of Neutralization Epitopes on HIV-1 Particles

To become infectious, HIV-1 particles undergo a maturation process involving proteolytic cleavage of the Gag and Gag-Pol polyproteins. Immature particles contain a highly stable spherical Gag lattice and are impaired for fusion with target cells. The fusion impairment is relieved by truncation of the gp41 cytoplasmic tail (CT), indicating that an interaction between the immature viral core and gp41 within the particle represses HIV-1 fusion by an unknown mechanism. We hypothesized that the conformation of Env on the viral surface is regulated allosterically by interactions with the HIV-1 core during particle maturation. To test this, we quantified the binding of a panel of monoclonal antibodies to mature and immature HIV-1 particles by immunofluorescence imaging. Surprisingly, immature particles exhibited markedly enhanced binding of several gp41-specific antibodies, including two that recognize the membrane proximal external region (MPER) and neutralize diverse HIV-1 strains. Several of the differences in epitope exposure on mature and immature particles were abolished by truncation of the gp41 CT, thus linking the immature HIV-1 fusion defect with altered Env conformation. Our results suggest that perturbation of fusion-dependent Env conformational changes contributes to the impaired fusion of immature particles. Masking of neutralization-sensitive epitopes during particle maturation may contribute to HIV-1 immune evasion and has practical implications for vaccine strategies targeting the gp41 MPER.
Alterations of membrane integrity and cellular constituents by arachidonic acid in neuroblastoma and glioma cells

Abstract Effects of arachidonic acid on cellular metabolism, cation content, lipid peroxidation, sodium pump activities and release of labeled arachidonic acid were studied in C-6 glioma cells and N18TG2 neuroblastoma cells. Arachidonic acid caused a significant increase in intracellular sodium levels concomitant with a decrease in intracellular potassium in both cell lines. Both (Na+ + K+)- ATPase and ϱ-nitrophenyl phosphatase of glioma cells were inhibited by arachidonic acid whereas only the ϱ-nitrophenyl phosphatase of neuroblastoma cell was inactivated. Low concentrations of arachidonic acid stimulated lactic acid release whereas high concentrations had an opposite effect. In addition, the lipid peroxide content of glioma cells was increased abruptly by 50 μM arachidonic acid whereas only a slight increase of malondialdehyde was observed in neuroblastoma cells. When the cultured cells of both cell lines were incubated with exogenous labeled arachidonic acid, 78–95% of the label was incorporated into membrane phospholipids. Only a very small fraction of prostaglandin E2 and prostaglandin F2α was synthesized. Exogenous arachidonic acid and free radicals generated with xanthine-xanthine oxidase caused a significant release of endogenous labeled arachidonic acid from cellular membrane phospholipids. These data further support our hypothesis that the arachidonic acid and its oxygen radical metabolites induce pathological alterations in membrane permeability and cellular volume.
Consistent estimators of the variance-covariance matrix of the gmanova model with missing data

A common problem in multivariate general linear models is partially missing response data. The simplest method of analysis in the presence of missing data has been to delete all observations on any individual with any missing data(listwise deletion) and utilize a traditional complete data approach. However: this can result in a great loss of information: and perhaps inconsistencies in the estimation of the variance-covariance matrix. In the generalized multivariate analysis of variance(GMANOVA) model with missing data: Kleinbaum(1973) proposed an estimated generalized least squares approach. In order to apply this: however: a consistent estimate of the variance-covariance matrix is needed. Kleinbaum proposed an estimator which is unbiased and consistent: but it does not take advantage of the fact that the underlying model is GMANOVA and not MANOVA. Using the fact that the underlying model is GMANOVA we have constructed four other con¬sistent estimators. A Monte Carlo simulation experiment is conducted tto...
Globalization and Corporate Ethics

Ethical standards for corporations are today acknowledged and ratified by several international declarations. These standards are closely linked to the new world-wide stress on corruption free governments. The ultimate source of both Business Ethics and honesty in government lies in the now internationally accepted Universal Declaration of Human Rights.
Multi-analyte immunoassay using cleavable tags and microchip micellular electrokinetic chromatography

A new multi-analyte immunoassay designed to screen for several biomarkers using cleavable tag chemistry and micellular electrokinetic chromatography was evaluated.
High-fidelity Aeroelastic Analysis of Very Flexible Aircraft

This paper describes the development and capabilities of a high-fidelity aeroelastic simulation tool for very flexible aircraft (HiFi-VFA) within a Multi-Disciplinary Computing Environment (MDICE). The code loosely couples a geometrically nonlinear, quasi-3D structural solver with an Euler/Navier-Stokes flow solver capable of arbitrary, large, mesh deformation. Verification of the static aeroelastic solver is presented for a hypothetical high aspect ratio wing discussed in the literature. Time domain aeroelastic simulations using the new code generally agree well with the response of an in‐house aeroelastic simulation toolbox, but the high‐fidelity results suggest the presence of higher aerodynamic damping than predicted by the finite state aerodynamics. With these results, flutter boundaries are sought using two flutter prediction methods (ARMA and FMDS) and the advantages/disadvantages of these prediction methods in computational aeroelasticity are assessed.
A revision of Thyrsodium (Anacardiaceae)

Recent research for floristic treatments of the Anacardiaceae led to the discovery of three new species ofThyrsodium:T. rondonianum, T. bolivianum, andT. puberulum. Historically, the genus was confused with the burseraceous genusGaruga. Study of these genera has helped to refine our understanding of the relationships between the Anacardiaceae and Burseraceae. A revised description ofThyrsodium, a key to the species in the genus, descriptions, distribution maps, and notes on the distribution and ecology of all the species are provided.
Polynomial Weyl Representations

For the canonical commutation relations in infinite dimensions, we offer an explicit direct construction of Weyl representations generated from the Fock representation by polynomial transformations of arbitrary degree, solving a problem posed by Proksch, Reents and Summers. Our solution employs new approaches to Hilbert-Schmi dt polynomials and their Wick ordering.
The lifetime of conditioned Brownian motion in planar domains of infinite area

In this paper, it is shown that all expected lifetimes ofh-processes inD are finite if and only if the area ofD is finite ifD={(x,y):o_(x)>y<o+(x), − ∞<x<∞}, where o_(x)<o+ are two Lipschitz functions. We show that if Ω is a bounded convex region in the plane, there is anh-process in Ω with expected lifetime at leastc area (Ω). We also give an example of a planar domainD of infinite area such that the expected lifetime of eachh-process inD is finite.
Use of Low-cost Remote Sensing for Infrastructure Management

Many owner organizations use manual, visual methods for evaluating the condition of infrastructure. However, manual, visual evaluation is labor intensive, time consuming, and potentially dangerous. Advances in remote sensing technology, such as high-resolution, multispectral digital aerial photography and high-resolution airborne laser radar (LiDAR) provide new methods for collecting condition information on infrastructure assets that can be used for infrastructure management. To evaluate the potential for using remote sensing technology for infrastructure management, the authors compared data extracted from aerial photos and LiDAR with reference data on pavement surface conditions that were collected manually. The statistics of the spectral response of the bands within the digital aerial photographs and the elevation within the airborne LiDAR were extracted and correlated to the reference data using stepwise linear regression models. The results show that the spectral response in digital aerial photographs of 0.1524-m (6-in.) resolution and 1-m resolution with an infrared band closely match the reference data. The results also show that the elevation response in airborne LiDAR of 1-m resolution closely match the reference data. These results open the way for the future use of digital aerial photographs and LiDAR to assess the infrastructure system conditions remotely.
Connected to Birds but Not Bees: Valence Moderates Implicit Associations With Nature

The article discusses three experiments that replicated and extended prior research on implicit connections with built and natural environments. In Experiment I, participants classify “nature” (e.g., trees) and “self (e.g., me) items faster than “built” (e.g., factory) and “other” (e.g., them) items. This effect may attribute to words that elicit stronger positive associations to nature and stronger negative associations to built categories. In Experiment 2, participants rated nature and self items more positively than built and other items. This finding suggests a propensity to view oneself and the natural environment more favorably in comparison to others and the built environment This positive association to nature, however, was reversed in Experiment 3: Participants classify built and self items faster than nature and self items. Results indicate that stimulus valence moderates implicit associations to built and natural environments. Implications regarding the role of affective processing on implicit ...
Triple benzylic dehydrogenation by osmium in an amide ligand environment

The three benzylic methyl hydrogens of p-isopropyltoluene (cymene) are cleaved by ligating N(SiMe2CH2PtBu2)2- to [(cymene)OsCl2]2, to give a carbyne complex; its chemical reactivity with H2, with CO, and with HC⋮CH are described.
Histiotypic organization and cell differentiation in rat retinal reaggregate cultures

Abstract Reaggregate cultures have been formed from cell suspensions of enonatal rat retinas. Histological sections of the reaggregates showed evidence of lamination with central rosettes formed around a lumen, a clear neuropil layer and an outer cellular layer. Each of the major retinal cell types, except ganglion cells, could be positively identified using cell type-specific antibodies to label cryostat sections. Many of these were found to occupy positions within the reaggregates similar to those found in the intact retina. Electron microscopic observations showed abundant immature and mature synaptic endings within the neuropil layer, including a number of ribbon synapses. Examination of the rosettes showed an arrangement of Muller glia and photoreceptors that closely resembled that of the intact retina. Within the lumen of rosettes, photoreceptors were found to contain stacks of disc-like membranes bounded by a plasma membrane, analogous to immature outer segments. The photoreceptors within rosettes also underwent molecular differentiation and expressed an outer segment specific marker. The findings suggest that retinal cells have intrinsic properties that allow them to organize themselves into a correctly laminated structure and that particular cell interactions are necessary for continued differentiation of at least rod photoreceptors and Muller cells.
Disproportionately increased proinsulin levels are associated with the insulin resistance syndrome

Recent data suggest that proinsulin may be associated with increased cardiovascular risk factors in both diabetic and nondiabetic subjects. We examined the relation of insulin, proinsulin, and the fasting proinsulin/insulin ratio to a number of metabolic disorders believed to be related to the insulin resistance syndrome (low high density lipoprotein cholesterol and high triglyceride levels, hypertension, and impaired glucose tolerance). Proinsulin was measured by a RIA, and insulin was measured by a Linco RIA that does not cross-react with proinsulin. The increased fasting proinsulin/insulin ratio was significantly associated with hypertension, low high density lipoprotein cholesterol and high triglyceride levels, and impaired glucose tolerance in 423 nondiabetic subjects. The fasting proinsulin/insulin ratio increased significantly with the number of metabolic disorders (zero, 0.060; one, 0.086; two, 0.098; three, 0.177; four, 0.182; P < 0.001). The increased proinsulin/insulin ratio was also associated with a greater number of metabolic disorders in diabetic subjects. Our results show that particularly nondiabetic individuals with the insulin resistance syndrome not only have hyperinsulinemia as a marker of insulin resistance, but also show an increase in proinsulin relative to insulin, which may reflect relative beta-cell failure or malfunction.
The central limit problem for mixing sequences of random variables

In this paper the central limit problem is solved for sums of random variables having bounded variances and satisfying certain mixing conditions. In case of a stochastic process these mixing conditions essentially say that as time passes events concerning the “future” of the process are almost independent from the events in the “past”. It turns out that the class of limit laws for sums of mixing random variables is exactly the same as for the bounded variances case of independent random variables. We also shall give criteria for convergence to any specified law of this class of possible limit laws. Finally we shall derive the central limit theorem involving a kind of Lindeberg-Feller condition and as a corollary thereof a kind of Ljapounov theorem.
Mutagenesis of essential functional residues in acetylcholinesterase.

Abstract The cholinesterases are serine hydrolases that show no global similarities in sequence with either the trypsin or the subtilisin family of serine proteases. The cholinesterase superfamily includes several esterases with distinct functions and other proteins devoid of the catalytic serine and known esterase activity. To identify the residues involved in catalysis and conferring specificity on the enzyme, we have expressed wild-type Torpedo acetylcholinesterase (EC 3.1.1.7) and several site-directed mutants in a heterologous system. Mutation of serine-200 to cysteine results in diminished activity, while its mutation to valine abolishes detectable activity. Two conserved histidines can be identified at positions 425 and 440 in the cholinesterase family; glutamine replacement at position 440 eliminates activity whereas the mutation at 425 reduces activity only slightly. The assignment of the catalytic histidine to position 440 defines a rank ordering of catalytic residues in cholinesterases distinct from trypsin and subtilisin and suggests a convergence of a catalytic triad to form a third, distinct family of serine hydrolases. Mutation of glutamate-199 to glutamine yields an enzyme with a higher Km and without the substrate-inhibition behavior characteristic of acetylcholinesterase. Hence, modification of the acidic amino acid adjacent to the serine influences substrate association and the capacity of a second substrate molecule to affect catalysis.
Immunodominant, protective response to the parasite Toxoplasma gondii requires antigen processing in the endoplasmic reticulum

The Toxoplasma gondii peptides recognized by protective CD8+ T cells remain uncharacterized. Shastri and colleagues identify an immunodominant T. gondii peptide generated by a mechanism dependent on the endoplasmic reticulum aminopeptidase ERAAP. The parasite Toxoplasma gondii replicates in a specialized intracellular vacuole and causes disease in many species. Protection from toxoplasmosis is mediated by CD8+ T cells, but the T. gondii antigens and host genes required for eliciting protective immunity are poorly defined. Here we identified GRA6, a polymorphic protein secreted in the parasitophorous vacuole, as the source of the immunodominant and protective decapeptide HF10 presented by the H-2Ld major histocompatibility complex class I molecule. Presentation of the HF10–H-2Ld ligand required proteolysis by ERAAP, the endoplasmic reticulum aminopeptidase associated with antigen processing. Consequently, expansion of protective CD8+ T cell populations was impaired in T. gondii–infected ERAAP-deficient mice, which were more susceptible to toxoplasmosis. Thus, endoplasmic reticulum proteolysis is critical for eliciting protective immunity to a vacuolar parasite.