cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of external concentration fluctuations on leukocyte chemotactic orientation.

The quantitative dependence of leukocyte chemotactic orientation on imprecision in the measurement of chemoattractant concentrations from thermal fluctuations is analyzed. First, a mathematical model relating orientation to differences in receptor occupancy across cell dimensions is developed. This is then coupled with an extension of Berg and Purcell's analysis (1) of the precision of attractant concentration measurements by means of receptor occupancy. Our results show that thermal fluctuations in external concentrations can limit the accuracy of orientation, unless the measurement noise is reduced by averaging the measurements over a period of time. Comparison of our model predictions to experimental orientation data suggests that leukocytes do overcome this limitation, and allows estimation of the time-averaging period necessary to do so. For the orientation observed in a visual bridge assay by Zigmond (2) using the attractant peptide FNLLP, we estimate that receptor occupancy measurements for spatial comparison across cell dimensions must be averaged for a few minutes. Otherwise, the fluctuations in the attractant concentration near the cell will be too great to allow the observed degree of orientation.
Cholinergic projections from the basal forebrain to the basolateral amygdaloid complex: A combined retrograde fluorescent and immunohistochemical study

We have examined the location of cholinergic and non-cholinergic neurons that project to the rat basolateral amygdaloid nucleus by using choline acetyltransferase (ChAT) immunohistochemistry in combination with retrograde fluorescent tracing on the same tissue section. Since many tracer-and ChAT-positive neurons were identified in basal forebrain areas, including the ventral pallidum, we also stained many of the sections for glutamate decarboxylase, a suitable marker for the delineation of pallidal areas. Cholinergic neurons projecting to the basolateral amygdaloid nucleus were observed in a continuous territory stretching from the dorsal part of ventral pallidum, through sublenticular substantia innominata to ventral parts of globus pallidus and peripallidal areas. Non-cholinergic neurons projecting to the basolateral amygdaloid nucleus were found intermixed within the same structures and constitute approximately 25% of the amygdalopetal projection neurons in these ventral forebrain structures. Since amygdalopetal cholinergic neurons were demonstrated in areas generally recognized as giving rise to cholinergic projections to cerebral cortex, several retrograde double-labeling experiments with two different fluorescent tracers were performed for the purpose of detecting the possible existence of collateral projections. The results obtained showed that the cholinergic basal forebrain neurons in general project to only one forebrain region, and, furthermore, that the cholinergic system consists of partially overlapping subsets of neurons that project to various neocortical and allocortical areas and to the amygdaloid body.
Thermogravimetric Analysis of Dentin

Four peaks were observed in the differential primary weight loss with temperatures up to 1,000 C. The first and second peaks correspond to the loss of water and the volatilization of protein. The third peak results from the carbonate. The fourth peak, which occurs at 700 to 800 C, probably is related to the transformation of hydroxyapatite to β-tricalcium phosphate. A zero order of reaction was assumed, and the activation energies in vacuum were determined to be 10.2 and 12.5 kcal/mol for loss of water and protein, respectively.
A Micromachined Platform for Three Dimensional Dielectrophoretic Assembly of Gold Nanoparticles for Nanodevices

This paper reports a novel technological approach for three-dimensional (3D) assembly of gold nanoparticles with an average diameter of 52 nm using dielectrophoresis (DEP). To realize the 3D assembly, the authors have designed and fabricated a versatile self-aligned micromachined platform which is applicable for assembling metallic nanoparticles and nanostructures. The assembly process is achieved at room temperature and is compatible with conventional semiconductor fabrication and large scale nanoassembly. The current-voltage curves obtained from the 3D gold nanoparticle bridges demonstrate that the assembly is functional with resistance values between -26 and 118 Ohms. This method has applications in making high density three-dimensional interconnects, vertically integrated nano sensors and for in-line testing of manufactured conductive nanoelements.
Testing Free Will

This article describes three experiments that would advance our understanding of the import of data already generated by scientific work on free will and related issues. All three can be conducted with existing technology. The first concerns how reliable a predictor of behavior a certain segment of type I and type II RPs is. The second focuses on the timing of conscious experiences in Libet-style studies. The third concerns the effectiveness of conscious implementation intentions. The discussion of first two experiments highlights some important problems with certain inferences made on the basis of existing data in scientific work on free will. The discussion of the third calls attention to powerful evidence that conscious intentions sometimes are among the causes of corresponding actions. This evidence has been largely ignored in the literature on free will.
Aging and Immune Function: Molecular Mechanisms to Interventions

Abstract The immune system of an organism is an essential component of the defense mechanism aimed at combating pathogenic stress. Age-associated immune dysfunction, also dubbed “immune senescence,” manifests as increased susceptibility to infections, increased onset and progression of autoimmune diseases, and onset of neoplasia. Over the years, extensive research has generated consensus in terms of the phenotypic and functional defects within the immune system in various organisms, including humans. Indeed, age-associated alterations such as thymic involution, T cell repertoire skewing, decreased ability to activate naive T cells and to generate robust memory responses, have been shown to have a causative role in immune decline. Further, understanding the molecular mechanisms underlying the generation of proteotoxic stress, DNA damage response, modulation of ubiquitin proteasome pathway, and regulation of transcription factor NFκB activation, in immune decline, have paved the way to delineating signaling...
Fusion reactor design studies.

This progress report will give a detailed breakdown of the work accomplished for ARIES-III during the contract period, November 1, 1990 to October 31, 1991. The areas of effort discussed are: Neutronics; First-Wall; Shield; Safety; Systems; Startup and Shutdown; Energy Conversion; Ripple Loss; and Fuel Resources.
Introducing CATs to STEM faculty through graduate students

The success of any instructional style in promoting meaningful learning, whether novel or traditional, active or passive, is critically dependent on the engagement of students in the course of instruction. Improving engagement, whether explicitly or implicitly, is a central goal of effective pedagogy. Social learning strategies, such as active or collaborative learning, are one way of improving engagement. A specific type of these is classroom assessment techniques (CATs) as described by Angelo & Cross. This project examines both the impact of including CATs in courses on student engagement as measured through a brief questionnaire and the experience of faculty implementing the methods in their courses. Faculty are supported in their implementation through condensed literature and one-on-one mentoring. Results show that measures of student affect related to the course increase post-intervention and that faculty will continue to implement CATs in their courses.
Ethnic Networks and Illegal Immigration

Illegal immigration through human smuggling originating from the Fujian Province, China, has become a global issue, affecting at least 30 countries. The empirical research on the financial element of illegal immigration suggests the important role of an underground banking system. This study examines the role of ethnic networks in sustaining the operation of Chinese-operated informal fund transfer systems in the United States. The primary source of data is from in-depth interviews with illegal immigrants in New York City and Philadelphia. The findings show that as opposed to lineage-based networks, the networks based on regional dialect allowed illegal Fujianese immigrants, as well as underground bank proprietors, to take advantage of social capital inherent in the expatriate ethnic community. The high levels of trust between underground bank proprietors and their clientele can be understood as resulting from ethnic solidarity and enforceable trust. These features are found to be troublesome at the commun...
Mechanisms of inhibition of Erwinia amylovora by Erw. herbicola in vitro and in vivo

The mechanisms by which Erwinia herbicola inhibits Erwinia amylovora, the fire blight pathogen, were investigated. The optimum pH for growth of Erw. amylovora strain Ea273 in nutrient-yeast extract-glucose broth (NYGB) was 7.0 and growth was markedly reduced at pH values below 6.0. In contrast, the growth rates of Erw. herbicola strains Eh141 and Eh112Y were only slightly reduced at pH levels as low as 4.5, relative to pH 6-8. When Ea273 was grown in NYGB in the presence of Eh141 or Eh112Y, the media became acidic and lower populations of Ea273 were recovered, compared with populations from buffered NYGB. Acidification of plant tissue as a consequence of growth of Erw. herbicola did not occur, however, and thus acid-based inhibition of growth in planta is unlikely. The growth rates of nine strains of Erw. herbicola and their abilities to reduce the pH of NYGB did not correlate with their different abilities to prevent development of fire blight incited by Ea273 in a research apple orchard. When grown in mixed culture, Eh114 and Eh112Y grew to higher populations than Ea273 due to depletion of a nitrogen source needed by Ea273. The ability of 12 strains of Erw. herbicola to produce antibiotics inhibitory to Ea273 on a glucose-asparagine medium correlated with the effectiveness of the strains in suppressing fire blight. A crude preparation of the Eh318 antibiotic delayed development of disease in immature pear fruits incited by Ea273 but not by strain Ea273R318, which is resistant in vitro to the Eh318 antibiotic. Cells of Eh318 protected immature pear fruits more effectively from infection by Ea273 than from the resistant strain Ea273R318.
Hematopoietic stem cells: Challenges to expectations

The past year provided a number of challenges to our expectations regarding hematopoietic stem cell (HSC) biology. Evidence has emerged that HSCs arise intraembryonically before they can be detected in the yolk sac. A number of genes that may regulate the formation, self-renewal, or differentiation of HSC have been identified. New markers for purifying HSCs have also been described. Although different groups have attributed different properties to HSCs, it now appears that the differences may be explained by variations in assay conditions rather than by differences in the HSCs themselves. Finally, insights have emerged into the complexity of the regulation of HSC proliferation and adhesion properties.
Site-directed, recombination-mediated mutagenesis of a complex gene locus

We have generated a site-specific 17 bp insertion within a 38 kb chick globin gene cluster by employing the recombination abilities of Saccharomyces cerevisiae. This gene cluster contains four beta-type globin genes which share a high degree of sequence homology. In this procedure, a small fragment of beta A-globin DNA containing a 17 bp insertion is subcloned into a URA3-based yeast integrating vector (YIp). This mutated globin subclone is introduced into cells that carry the 38 kb globin cluster clone on a single-copy, circular vector derived from a yeast artificial chromosome (YAC). Insertion of the 17 bp oligomer is achieved by targeted integration of the Ylp subclone. The recombinant contains the normal beta A-globin gene, the mutant gene and Ylp vector sequences between the two copies. Excision of the vector sequences and one copy of the duplicated globin sequences by homologous recombination is required for cell survival when exposed to the selective agent 5-fluoroorotic acid, which is toxic to ura+ yeast cells. Depending upon the point of the cross-over, a ura- yeast cell bearing either a wild-type globin gene or a 17 bp insertion mutation will result. By restriction mapping and in vitro transcription analysis, the beta A-globin gene containing the 17 bp insert has no nonspecific mutations generated during the recombination and selection procedures. Specific mutations of regulatory regions, including protein-DNA binding sites, can be accurately targeted within extensive DNA clones by this method.
A crown ether, template-driven, macrolide closure

Abstract Macrolide formation from reactive crown ether 1 is driven by the proximate binding of alkoxide and thioester functionalities.
Chemometrics with undergraduates

Abstract Kalivas, J., 1992. Chemometrics with undergraduates. Chemometrics and Intelligent Laboratory Systems, 15:127–135. This paper reviews John Kalivas' work as an evolving chemometrician. Discussion concentrates on his most recent investigations with the generalized simulated annealing (GSA) optimization algorithm and library searches of spectrochromatograms. Generalized simulated annealing represents an optimization procedure for determining global optima of multidimensional response surfaces. Studies described encompass GSA selection of regression variables and principal components for principal component regression. Results are also presented using condition index evolving profiles for library searching spectrochromatograms.
Sea Urchin Response to Foreign Substances

An assessment of the response of Strongylocentrotus purpuratus to substances injected into the coelom shows that (i) foreign molecules are cleared from the coelomic fluid more rapidly than native molecules, (ii) coelomocytes can respond selectively to albumins of human and bovine origin, and (iii) immunization attempts fail to elicit accelerated coelomocyte uptake or accelerated clear-with antigen.
Parameter-extraction of a two-compartment model for whole-cell data analysis.

Neuronal modeling of patch-clamp data is based on approximations which are valid under specific assumptions regarding cell properties and morphology. Certain cells, which show a biexponential capacitance transient decay, can be modeled with a two-compartment model. However, for parameter-extraction in such a model, approximations are required regarding the relative sizes of the various model parameters. These approximations apply to certain cell types or experimental conditions and are not valid in the general case. In this paper, we present a general method for the extraction of the parameters in a two-compartment model without assumptions regarding the relative size of the parameters. All the passive electrical parameters of the two-compartment model are derived in terms of the available experimental data. The experimental data is obtained from a DC measurement (where the command potential is a hyperpolarizing DC voltage) and an AC measurement (where the command potential is a sinusoidal stimulus on a hyperpolarized DC potential) performed on the cell under test. Computer simulations are performed with a circuit simulator, XSPICE, to observe the effects of varying the two-compartment model parameters on the capacitive transients of the current response. Our general solution for the parameter-estimation of a two-compartment model may be used to model any neuron, which has a biexponential capacitive current decay. In addition, our model avoids the need for simplifying and perhaps erroneous approximations. Our equations may be easily implemented in hardware/software compensation schemes to correct the recorded currents for any series resistance or capacitive transient errors. Our general solution reduces to the results of previous researchers under their approximations.
Specification of stored data structures and desired output results in DIAM II with FORAL

The primary goal for a specification language is to provide a means for accurate, succinct description of processing algorithms and their related data structures: in effect, a description with a minimum of extraneous detail. In general, progress toward this goal has been achieved by moving from assembly languages with their requirement for detailed knowledge of data processing structures to notations, such as the mathematical formalisms, which avoid the use of specific computer representations. In this sense, FORTRAN, ALGOL, and PL/I are early specification languages, while APL, the Vienna Definition Language, and SETL are more advanced forms.
High night temperatures delay flowering, produce abnormal flowers and retard stem growth of cut-flower chrysanthemums

Abstract The responses of chrysanthemum ( Dendranthema grandiflora Tzvelev) cultivars ‘Polaris’ and ‘White Marble’ to night temperatures of 32°C depended on the duration of exposure and the time of transfer to the high night temperature. Transfer for 7 nights at the start of short-day treatment (SD) delayed the onset of flower bud initiation, while transfer for longer, delayed the completion of flower bud formation. When transfer was made for 42 nights from the start of SD, no florets were initiated at the extreme tip of the receptacle in either cultivar throughout the period of transfer. Transfers that delayed flower bud initiation also delayed anthesis, though the effect was generally less. The greatest delay in anthesis occurred when the high night temperature was given at the onset of floret initiation, i.e. between 14 and 21 SD. Transfer at this time also caused the production of more disc florets in ‘Polaris’ and the formation of bracts among the disc florets of ‘White Marble’. Transfer to high night temperature at any stage induced foliar chlorosis and retarded stem extension, though final stem length was not significantly shortened. Attention is drawn to the need to reduce night temperature under black-out covers in summer, especially between 14 and 21 SD, and to some methods of achieving this.
Coping Processes Among Bereaved Spouses

The authors investigated if an intervention based on the dual process model (vs. traditional bereavement support) enhanced oscillation between loss- (LO) and restoration-oriented (RO) coping of recently bereaved (2-6 months) spouses/partners. Participants were followed over 12 months. The authors found an increased emphasis over time on RO coping, particularly for women and those who were younger; however, no treatment effect was detected. Although patterns in the data are consistent with the model, the authors conclude that it is difficult for interventions to modify LO, RO, and oscillation unless there is sufficient intervention dosage and tailored to those exclusively engaged in one process.
Out-of-Focus Photometry*

The paper presents a theoretical development of the optical characteristics of photometers employing lenses. Both in-focus and out-of-focus operation are analyzed in detail for three types of photometers: a photometer employing fixed apertures, a photometer employing a simple lens, and a photometer employing a combination of a simple lens and a fixed aperture. The range of satisfactory operation of such instruments is carefully defined, as well as the gross errors which may occur in special applications.
Intergenerational conflicts in gulls

Abstract Gulls (genus Larus) are known both to adopt and to attack and kill unrelated offspring wandering through their territories. The tendency of adult gulls to accept unrelated offspring appears to counter standard Darwinian natural selection, and has been interpreted as kin selection, altruism, or reproductive error. Another alternative, not generally advanced, is that there is an intergenerational conflict in which gull chicks receiving inadequate parental care seek parental care from unrelated adults, and the adults try to prevent this from happening. In this study, chicks that abandoned their natal territories were being fed at low rates or were growing slowly compared to siblings, or were the recipients of siblicidal aggression. Of the chicks that abandoned their parents, around 20–30% became successfully adopted, and a similar percentage were killed by conspecific adults. Selection should favour the chicks winning the conflict, since if they are not adopted they will perish, whereas the cost to an adult that adopts an unrelated chick will be measured in lost time and energy, which may have little or no effect on future reproductive potential. The concept of an intergenerational conflict in which adults care for unrelated offspring may be of general applicability to those species that have precocial offspring.
Straining towards trust: some constraints essay on studying trust in organizations

Trust is of great interest in organizational research and the social sciences. It is argued here that any theory of trust ought to treat a set of observed empirical regularities as constraints. A constraint on a theory is either an assumption made in constructing the theory (e.g., we assume people have a tendency to be fair in their dealings with others) or an explanandum (e.g., we must explain the tendency people have to be fair in their dealings with others) for which the theory must account. These constraints are best thought of in an evolutionary framework, with intellectual links to game theory, evolutionary biology and evolutionary psychology. In particular, (1) people are disposed towards fairness and reciprocity, they have (2) cognitive modules and (3) emotional dispositions which safeguard them against cheating and trust violation. Given these three constraints, any theory should consider the (4) evidence for cultural constraints on trust, trusting behavior and decisions. These constraints together point us towards an integrated ecology of trust where culture, individual dispositions and cognition jointly influence observed trusting behavior. Some work, particularly Gintis et al. (2002) on altruism, strong reciprocity and cooperation, suggests such an approach to studying trust. The purpose of this essay is to identify this work, organize it, and argue for its bearing on the study of trust and organizations. Copyright © 2003 John Wiley & Sons, Ltd.
Exploration of cyanine compounds as selective inhibitors of protein arginine methyltransferases: synthesis and biological evaluation.

Protein arginine methyltransferase 1 (PRMT1) is involved in many biological activities, such as gene transcription, signal transduction, and RNA processing. Overexpression of PRMT1 is related to cardiovascular diseases, kidney diseases, and cancers; therefore, selective PRMT1 inhibitors serve as chemical probes to investigate the biological function of PRMT1 and drug candidates for disease treatment. Our previous work found trimethine cyanine compounds that effectively inhibit PRMT1 activity. In our present study, we systematically investigated the structure–activity relationship of cyanine structures. A pentamethine compound, E-84 (compound 50), showed inhibition on PRMT1 at the micromolar level and 6- to 25-fold selectivity over CARM1, PRMT5, and PRMT8. The cellular activity suggests that compound 50 permeated the cellular membrane, inhibited cellular PRMT1 activity, and blocked leukemia cell proliferation. Additionally, our molecular docking study suggested compound 50 might act by occupying the cofact...
Behavioral Effectiveness of Warnings

A paradigm was developed to examine the effectiveness of warnings in a laboratory task. A task was presented to subjects as one examining how people perform a basic chemistry demonstration. Experiment 1 examined the effects of two locations of the warning (before and after instructions) and two different signal word presentations (WARNING and Note). An additional condition with no warning or signal word served as a control. No effects were found on time or accuracy. However, compliance (use of mask and gloves) was affected by the inclusion of the warning as well as by its location. Greatest compliance occurred when the warning was placed prior to the instructions. Experiment 2 replicated the effect of location. The addition of a printed statement placed before the instructions (with warning at the end) to read through the instructions before beginning produced intermediate compliance that was not significantly different from the warning beginning and end conditions. Observation revealed that when the warn...
Antibacterial efficacy of triclosan-incorporated polymers.

Abstract Triclosan (2, 4, 4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antimicrobial agent, routinely used in various personal care products. 1 It is also incorporated into polymers through melt-mixing, with the aim of providing persistent antibacterial action on the surface of the polymer. 2,3 Such triclosan-incorporated polymers can be promoted for hospital use as fabric seat covers, tables, chairs, and clothing. We assessed the antibacterial efficacy of triclosan-incorporated polymer disks against 2 bacteria cultured in liquids in contact with the polymer. In spite of the relatively high concentrations of triclosan in the polymer, only some initial slowing of the bacterial growth rates was observed, followed by the absence of an antibacterial effect over extended periods. The triclosan at the surface of the disks dissolves into the liquids, and the rest of the triclosan, immobilized in the disks, does not contribute to the antibacterial effectiveness of triclosan-incorporated polymer. In light of recent studies, which have shown that triclosan acts on a specific target within the bacterial lipid synthesis pathway, triclosan-incorporated polymers may provide the ideal setting for resistant strains of bacteria to grow and thus should be used selectively in hospital environments. (AJIC Am J Infect Control 2001;29:124-6)
25-OH Vitamin D: Is It the Universal Panacea for Metabolic Syndrome and Type 2 Diabetes?

Obesity has become a global epidemic. Consequently, thereareincreasingratesofobesity-relateddiseases such as diabetes, cardiovascular diseases, sleep disorders, andassociatedmorbidityandmortality.Althoughthereis growing debate on the etiopathogenesis of the global pandemic of obesity, there is no question that increasing calories, concomitant decreases in physical activity, and increasingsedentarylifestylearemajorcontributors.Typically, obesity is associated with insulin resistance/hyperinsulinemia, which has been implicated in the increased cardiovascular diseases, metabolic syndrome, and type 2 diabetes.Metabolically,obesityisassociatedwithreduced high-densitylipoproteincholesterolandhightriglycerides and increases in serum total cholesterol, low-density lipoprotein, and small, dense, low-density lipoprotein cholesterol particles. In addition, obesity is regarded as a proinflammatory state with increases in the oxidative stress burden, free oxygen radicals, and F2-isoprostanes. However,theassociationsofobesityandmetabolicderangements are very complex. Although there are direct causal relationships of some of these metabolic derangements with obesity, in some situations, the metabolic change can be a consequence of the obesity per se. Recently, several epidemiological studies have reported increasing prevalence of low serum 25-hydroxy vitamin D (25-OH vitamin D) levels in several communities around the globe. In contrast to old literature, where specific demographic populations such as elderly patients living in higherlatitudesandaltitudes,geographicalareaswithlow sun exposure, religious practices, etc. posed greater risk, there are alarming rates of low serum 25-OH vitamin D levels among seemingly healthy populations, especially in the elderly in the Western industrialized world. This has
Asymptotic inverse spectral problem for anharmonic oscillators

We study perturbationsL=A+B of the harmonic oscillatorA=1/2(−∂2+x2−1) on ℝ, when potentialB(x) has a prescribed asymptotics at ∞,B(x)∼|x|−αV(x) with a trigonometric even functionV(x)=Σamcosωmx. The eigenvalues ofL are shown to be λk=k+μk with small μk=O(k−γ), γ=1/2+1/4.
Genetic diversity, population structure, and resistance to Phytophthora capsici of a worldwide collection of eggplant germplasm

Eggplant (Solanum melongena L.) is an important solanaceous crop with high phenotypic diversity and moderate genotypic diversity. Ninety-nine genotypes of eggplant germplasm (species (S. melongena, S. incanum, S. linnaeanum and S. gilo), landraces and heirloom cultivars) from 32 countries and five continents were evaluated for genetic diversity, population structure, fruit shape, and disease resistance to Phytophthora fruit rot. Fruits from each line were measured for fruit shape and evaluated for resistance to two Phytophthora capsici isolates seven days post inoculation. Only one accession (PI 413784) was completely resistant to both isolates evaluated. Partial resistance to Phytophthora fruit rot was found in accessions from all four eggplant species evaluated in this study. Genetic diversity and population structure were assessed using 22 polymorphic simple sequence repeats (SSRs). The polymorphism information content (PIC) for the population was moderate (0.49) in the population. Genetic analyses using the program STRUCTURE indicated the existence of four genetic clusters within the eggplant collection. Population structure was detected when eggplant lines were grouped by species, continent of origin, country of origin, fruit shape and disease resistance.
Physical inactivity and working hour inflexibility: evidence from a U.S. sample of older men

Lack of time is the most frequently reported reason for lack of exercise. This study examines how restriction on the number of working hours affects individuals’ exercise decision. A structural model is constructed to describe the simultaneous decisions of employment and physical activity in the presence of working hour restriction. Using data from the 1992 Health and Retirement Study, this study finds that the working hour restriction is partly responsible for the physical inactivity among older American workers. When the working hour restriction is binding from below, an increase in the number of hours required on the job considerably reduces the probability of engaging in frequent exercise. The results imply that partial relaxation of working hour restrictions may be considered to promote frequent exercise.
Changes in Population Structure of Diamondback Terrapins (Malaclemys terrapin terrapin) in a Previously Surveyed Creek in Southern New Jersey

Abstract Population structure of Malaclemys terrapin terrapin in an unaltered creek in southern New Jersey was compared to data collected 12–13 years earlier. I found significantly lower average carapace size of terrapins and lower frequency of adult females compared to the earlier survey, and speculate that road mortality of nesting females may be responsible for these trends.
Methanol at the water–platinum interface studied by ab initio molecular dynamics

Abstract The adsorption and initial dehydrogenation of methanol on Pt(1 1 1) is examined using ab initio molecular dynamics. The simulations reveal that in solution the methanol molecule orientates with the CH 3 group towards the surface, in contrast to the vacuum adsorption geometry. Our calculations also show that in vacuum the initial dehydrogenation step of CH 3 OH → CH 2 OH + H has an energy barrier of only 0.45 eV, in good agreement with experimental results. We find a lowering and smearing of high-frequency hydrogen modes as a result of the methanol–surface interaction. The inclusion of hydration introduces additional effects and is necessary for a realistic treatment of the system.
Bovine interstitial retinol-binding protein (IRBP)—isolation and sequence analysis of cDNA clones, characterization and in vitro translation of mRNA

Three clones for b-IRBP were isolated by anti b-IRBP screening of two bovine retina libraries in the expression vector lambda gt11. The cDNA inserts were then used as hybridization probes to screen and isolate three more clones in a bovine retina library in the non-expression vector lambda gt10. The six overlapping clones generated a b-IRBP cDNA sequence of 3400 nucleotides. An open reading frame encoded the complete amino acid sequences of 8 of the 35 b-IRBP tryptic peptides purified in the present study. One tentative glycosylation site was identified. The coding region was followed by TAG translation terminating codon and an untranslated stretch of about 1700 nucleotides that ended in a sequence containing a presumptive AATAAA polyadenylation signal that was 18 nucleotides upstream from a 10 nucleotide oligo(A) tract. The coding region for b-IRBP would be expected to be 3300 bp long, but Northern blot hybridization experiments performed with bovine retina polyadenylated RNA and probes containing part of the coding region established that the mRNA for b-IRBP consisted of a major species of about 6300 bp, and a minor species of 5200 bp. In vitro translation of bovine retina polyadenylated RNA in a rabbit reticulocyte lysate system yielded an immunoreactive protein that was comparable in size with nonglycosylated, mature IRBP, showing that it is not synthesized from a large precursor, and supporting our finding that the mRNA contains an extensive non-coding region.
Test Release of Itoplectis quadricingulatus Against European Pine Shoot Moth in an Isolated Infestation

A total of 5365 female Itoplectis quodricingulatus (Provancher) was released on a 40-acre site over a 7-week period when pupae of the European pine shoot moth, Rhyacionia buoliana (Schiffermuller), were present. Activity and parasitizing ability of the parasites were estimated from weekly parasitization of wax moth pupae hung from tree branches. Effectiveness of the release against shoot moth was evaluated by comparing parasitization of shoot moth pupae in exposed and caged branches. About 50% of the wax moth pupae but only 30% of the shoot moth pupae were killed by I. quadricingulatus .
Response classification of simple polycrystalline microstructures

Abstract A new method for approximate solution of mechanics problems is presented that uses a classifier to identify regions in a random heterogeneous material where stress is likely to be highly concentrated under a prescribed set of boundary conditions. The example problem studied is an aggregate of hexagonal grains, each modeled as orthotropic and linear elastic, and subject to uniaxial extension. It is shown that the Sobol’ decomposition can be used to determine which surrounding grains mechanical properties play the largest role in determining the average effective stress in any particular grain. It is also shown that the constituent functions of the Sobol’ decomposition determine a unique material pattern that corresponds to maximum stress concentration. A reduced order representation of the microstructure is developed that is in essence a projection of the microstructure description onto the material pattern. Finally, a classifier is developed that operates on this reduced order representation to predict the level of stress concentration. This classifier is shown to be over 90% accurate, and, when implemented in a moving window algorithm, to provide very good predictions of the subregions in a large microstructure where large stress concentration is likely.
Carcinogen testing fact and fallacy

In the absence of human information on the carcinogenicity of chemical substances, one must rely primarily on information from long-term animal testing. Although far from perfect, animal studies seem to be reasonable predictors of the human experience, both qualitatively and quantitatively. Short-term tests for genotoxicity may be helpful for establishing priorities for chemical testing, but they are not as strong indicators of potential carcinogenicity as had been previously thought. New directions in toxicologic research hold the promise for scientists being able to perform more reasoned assessments of carcinogenic risk.
Excimer laser phototherapeutic keratectomy: long-term results and practical considerations.

Purpose Our purpose was to evaluate the safety and short- and long-term efficacy of excimer laser phototherapeutic keratectomy (PTK) to treat anterior corneal pathology. Methods Twenty-eight eyes of 24 patients underwent PTK for anterior corneal pathologic conditions with a VISX excimer laser. Preoperative indications included granular dystrophy (six eyes), superficial variant of granular dystrophy (six eyes), and Salzmann's nodular degeneration (five eyes). Three eyes had recurrent erosions, and two eyes had keratoconus nodules. Additional diagnoses included other corneal dystrophies and various corneal scars. Mean follow-up time was 22.5 months (range, 5-44). One eye underwent a repeated PTK for recurrent scarring 1 year after the initial procedure and is included in the results. Results The mean time to reepithelialization was 4.2 days (range, 2-11). Corneal smoothness and clarity improved in all patients. Uncorrected visual acuity improved a mean of 1.4 lines (range, -6 to +8 lines) and best corrected visual acuity improved a mean of 2.7 lines (range, -3 to +7 lines). Mean corneal flattening was 2.13 D (range, 7.75. D flatter to 6.5 D steeper). The preoperative goal was achieved in 22 (78.5%) of 28 eyes, with no significant change in five (18%) eyes and functional worsening in one (3.5%) eye. Five eyes developed moderate to significant recurrences of their pathology, including the retreated eye. Conclusion Excimer laser PTK is safe and effective for the treatment of anterior corneal pathology. Recurrence of pathology, especially corneal dystrophies, do occur with time.
Biochemical specificity in central pathways related to peripheral and intracerebral homeostatic functions

Abstract Immunohistochemical and horseradish peroxidase (HRP) studies suggest that oxytocin-stained fibers from the paraventricular nucleus of the hypothalamus (PVH) innervate the locus coeruleus (LC) and dorsal vagal complex (DVC) in the brainstem of the rat, and that adrenergic fibers from the LC and DVC in turn project to the PVH. It is hypothesized that these pathways are directly involved in the integration of neuroendocrine and autonomic responses in the periphery, as well as in the mediation of homeostatic-preserving responses within the CNS itself.
Fecal occult blood testing for colorectal cancer screening: use the finger.

Abstract OBJECTIVE: Fecal occult blood testing (FOBT) has been widely underused as a means of colorectal cancer screening. Less than 35% of Americans have had the recommended FOBT in the last 5 yr. Guidelines suggest FOBT of three spontaneously passed stools (SPS) on a prescribed diet. Testing stool obtained by digital rectal exam (DRE) is discouraged because its yield in colorectal cancer screening is unknown. The aim of this study is to compare the positive predictive value of FOBT for the detection of colorectal neoplasia done by SPS versus DRE in asymptomatic outpatients. METHODS: Medical records and endoscopic reports of all patients who underwent colonoscopy between 1984–1999 for a positive FOBT were reviewed. Only asymptomatic outpatients whose indication was colorectal cancer screening were included. The method of FOBT was confirmed as either SPS or DRE. χ2 was used to compare the yield of detecting colorectal neoplasia between SPS and DRE. RESULTS: A total of 165 patients with a mean age of 61 yr (range 33–85) were included (84 patients were women). Neoplasia was detected in 29 of 80 (36%) with SPS and 28 of 85 (33%) with DRE (p = 0.18). CONCLUSIONS: The positive predictive value of FOBT on DRE for detecting neoplasia is similar to that of SPS in asymptomatic outpatients undergoing colorectal cancer screening. Positive FOBT on DRE warrants colonoscopic evaluation. Hemoccult testing by DRE may be performed in the office to increase patient compliance with colorectal cancer screening. A negative FOBT on DRE should be followed up with FOBT of SPS.
Bridge Health Index for the City and County of Denver, Colorado. II: Denver Bridge Health Index

Current bridge health index (BHI) in Pontis bridge management system applied to assess the bridge health conditions for 615 bridges in the city and county of Denver (CCD) does not provide CCD engineers a valuable analysis of the health condition of its relatively small bridge network. Both the calculation results and the computing methodology of the current BHI reveal that it is subjective to a municipality’s often imprecise cost data. This paper focuses on developing an alternate BHI. In order to understand the principle and procedure of the BHI calculation, the element weighting point was developed as a new concept in the analysis. The study concluded that the weighting point should reflect the effect of element damage on bridge health and function instead of a percentage of element value. Based on this conclusion, the current BHI was modified. The Denver BHI, a new diagnostic tool, was developed. It has already been adopted in the Pontis bridge management system of the CCD public works department.
Atomization of coal-water slurry using twin-fluid jet atomizer

This paper presents both experimental and modelling results of airblast atomization of coal-water mixtures or slurries (CWMs) using a twin-fluid jet atomizer. Specifically, the mass median diameter (MMD) of atomized droplets is related to the slurry properties and atomization conditions through its power dependencies on the Weber number (We), the Ohnesorge number (Z) and liquid or fuel-to-air mass ratio (WFWA), namely, MMDDF = (A · We−x + B · Z2x) (1 + WFWA)y, where DF = the diameter of the fuel passage and A, B, x and y are constants determined by the least square method. The coal particle size and size distribution has substantial effects on both the droplet sizes and the exponents x and y. In addition, the presence of hydrophobic coal particles shifts the fundamental mechanisms of airblast atomization to the predominance of the fuel viscosity included in Z over the liquid surface tension included in We. Other factors such as particle packing efficiency also make significant contributions.
Kinetic energies of excited atoms ejected from ion-bombarded surfaces☆

Abstract The decay of photon yield from sputtered excited atoms as a function of the perpendicular distance from an ion-bombarded surface has been measured for four particular transitions using an intensified silicon intensifier target (ISIT) detector and an optical multichannel analyzer (OMA) with 512 channels. This experimental approach has resulted in greatly improved spatial resolution than previous attempts, making it possible to examine in detail the decay from departing atoms close to the target surface, thereby circumventing to some extent the long-lived cascade contribution. The kinetic energies derived are compared with previous measurements and their implication to the excitation process in sputtering is discussed.
Relative importance of photosynthetic physiology and biomass allocation for tree seedling growth across a broad light gradient

Studies of tree seedling physiology and growth under field conditions provide information on the mechanisms underlying inter- and intraspecific differences in growth and survival at a critical period during forest regeneration. I compared photosynthetic physiology, growth and biomass allocation in seedlings of three shade-tolerant tree species, Virola koschynii Warb., Dipteryx panamensis (Pittier) Record & Mell and Brosimum alicastrum Swartz., growing across a light gradient created by a forest-pasture edge (0.5 to 67% diffuse transmittance (%T)). Most growth and physiological traits showed nonlinear responses to light availability, with the greatest changes occurring between 0.5 and 20 %T. Specific leaf area (SLA) and nitrogen per unit leaf mass (N mass) decreased, maximum assimilation per unit leaf area (A area) and area-based leaf N concentration (N area) increased, and maximum assimilation per unit leaf mass (A mass) did not change with increasing irradiance. Plastic responses in SLA were important determinants of leaf N and A area across the gradient. Species differed in magnitude and plasticity of growth; B. alicastrum had the lowest relative growth rates (RGR) and low plasticity. Its final biomass varied only 10-fold across the light gradient. In contrast, the final biomass of D. panamensis and V. koschynii varied by 100- and 50-fold, respectively, and both had higher RGR than B. alicastrum. As light availability increased, all species decreased biomass allocation to leaf tissue (mass and area) and showed a trade-off between allocation to leaf area at a given plant mass (LAR) and net gain in mass per unit leaf area (net assimilation rate, NAR). This trade-off largely reflected declines in SLA with increasing light. Finally, A area was correlated with NAR and both were major determinants of intraspecific variation in RGR. These data indicate the importance of plasticity in photosynthetic physiology and allocation for variation in tree seedling growth among habitats that vary in light availability.
CO2-fixation Sites in Leaves of Maize and Oats

The primary site of photosynthetic carbon dioxide fixation was determined in the leaves of two monocot species by means of microautoradiographic techniques. Carbon fixation occurred primarily in the vascular-bundle sheath cells in maize whereas fixation in oat occurred uniformly throughout the leaf. The evidence presented suggests that the bundle sheath cells of maize fix carbon via the C-4 dicarboxylic acid pathway.
Origin and differentiation of the yolk sac and extraembryonic mesoderm in presomite human and rhesus monkey embryos

Reexamination of presomite human and rhesus monkey embryos in the Carnegie Collection provides no evidence to corroborate the hypothesis that the trophoblast is the source of all extraembryonic tissues in these embryos. Instead, the present study indicates that the developmental pattern of the yolk sac and extraembryonic mesoderm is homologous to that in other eutharian mammals. The primary yolk sac of 10- to 11-day human blastocysts is partially filled with a meshwork of extraembryonic endoderm, whereas such a meshwork is absent in the rhesus monkey. It is suggested that this endodermal meshwork develops as the result of interstitial implantation in the human embryo. A small secondary yolk sac develops in 12- to 13-day human and macaque embryos as the result of pinching off of a portion of the larger primary yolk sac. Development of a secondary yolk sac in higher primates appears to be related causally to differential rates of expansion of the blastocyst and primary yolk sac within the simplex uterus. The caudal margin of the primitive streak develops precociously in 12- to 14-day human and macaque embryos, and this appears to be the source of all the extraembryonic mesoderm of the chorion, chorionic villi, and body stalk. It is suggested that the peripheral spread of extraembryonic mesoderm plays in inductive role in the development of chorionic villi, similar to other types of epithelial-mesenchymal inductive interactions. In contrast to previous hypotheses, the human and macaque trophoblasts appear to give rise only to additional trophoblast.
Characterization of SnO 2 GIAR films

In an attempt to develop a monochromator of synchrotron radiation ((Delta) E approximately 10-6 eV) using grazing incidence antireflection (GIAR) principle, we made SnO2 GIAR films on Pd (buffer layer) / (alpha) -Al2O3 (substrate). Films are fabricated by magnetron sputtering technique and characterized film thickness and interface roughness by x-ray diffraction technique using the conventional and synchrotron radiation sources. We demonstrated the electronic scattering suppression of approximately 10-2 and that the present system is feasible to achieve the required goals for monochromatization of synchrotron radiation source for the energy range of 23.87 keV.