cssi/SciSciGPT-SciSciNet huggingface dataset:
Dopamine D2 receptor mechanisms contribute to age-related cognitive decline: the effects of quinpirole on memory and motor performance in monkeys

The D2 dopamine (DA) receptor agonist, quinpirole, was characterized in young adult monkeys, young reserpine-treated monkeys and aged monkeys to assess the contribution of DA to age-related loss of prefrontal cortical (PFC) cognitive function. Monkeys were tested on a delayed response memory task that depends on the PFC, and a fine motor task that taps the functions of the motor cortex. In young adult monkeys, low quinpirole doses impaired performance of the PFC and fine motor tasks, while higher doses improved memory performance and induced dyskinesias and "hallucinatory-like" behaviors. The pattern of the quinpirole response in reserpine-treated monkeys suggested that the impairments in delayed response and fine motor performance resulted from drug actions at D2 autoreceptors, while the improvement in delayed response performance, dyskinesias and "hallucinatory-like" behaviors resulted from actions at postsynaptic receptors. In aged monkeys, low doses of quinpirole continued to impair fine motor performance, but lost their ability to impair delayed response performance. The magnitude of cognitive improvement and the incidence of "hallucinatory-like" behaviors were also reduced in the aged animals, suggesting some loss of postsynaptic D2 receptor function. The pattern of results is consistent with the greater loss of DA from the PFC than from motor areas in aged monkey brain (Goldman-Rakic and Brown, 1981; Wenk et al., 1989), and indicates that DA depletion contributes significantly to age-related cognitive decline.
Cigarette and alcohol consumption and the risk of colorectal cancer in Shanghai, China

The relation of cigarette smoking and alcohol drinking to colorectal cancer risk has been inconsistent in the epidemiological literature. In a population-based case-control study of colorectal cancer in Shanghai, China, where the incidence rates are rising sharply, we examined the association with tobacco and alcohol use. Cases were aged 30-74 years and newly diagnosed with cancers of the colon (N = 931) or rectum (N = 874) between 1990 and 1992. Controls (N = 1552) were randomly selected among Shanghai residents, frequency-matched to cases by gender and age. Information on lifetime consumption of tobacco and alcohol, as well as demographic and other risk factors, was obtained through in-person interviews. Associations with cigarette smoking and alcohol use were estimated by odds ratios (ORs) and 95% confidence intervals (CIs). Among women, the prevalence of smoking and alcohol drinking was low, and no significant association with colon or rectal cancer was observed. Although cigarette smoking among men was not related overall to colon or rectal cancer risk, there was a 50% excess risk of rectal cancer (OR 1.5, 95% CI 0.9-2.5) among those who smoked 55 or more pack-years. Among men, former alcohol drinkers had an increased risk of colon cancer (OR 2.3, 95% CI 1.4-3.7) but not rectal cancer, while current drinkers had a 30-50% excess risk of colon cancer only among those with long-term (30+ years) and heavy (>560 g ethanol/week) consumption. The excess risks were mainly associated with hard liquor consumption, with no material difference in risk between proximal and distal colon cancer. Although cigarette smoking and alcohol drinking in general were not risk factors for colorectal cancers in Shanghai, there were small excess risks for rectal cancer among heavy smokers and colon cancer among heavy drinkers.
A constrained mixture approach to mechano-sensing and force generation in contractile cells

Abstract Biological tissues are very particular types of materials that have the ability to change their structure, properties and chemistry in response to external cues. Contractile cells, i.e. fibroblasts, are key players of tissue adaptivity as they are capable of reorganizing their surrounding extra-cellular matrix (ECM) by contracting and generating mechanical forces. This contractile behavior is attributed to the development of a stress-fiber (SF) network within the cell’s cytoskeleton, a process that is known to be highly dependent of the nature of the mechanical environment (such as ECM stiffness or the presence of stress and strain). To describe these processes in a consistent manner, the present paper introduces a mutiphasic formulation (fluid/solid/solute mixture) that accounts for four major elements of cell contraction: cytoskeleton, cytosol, SF and actin monomers, as well as their interactions. The model represents the cross-talks between mechanics and chemistry through various means: (a) a mechano-sensitive formation and dissociation of an anisotropic SF network described by mass exchange between actin monomer and polymers, (b) a bio-mechanical model for SF contraction that captures the well-known length–tension and velocity–tension relation for muscles cells and (c) a convection/diffusion description for the transport of fluid and monomers within the cell. Numerical investigations show that the multiphasic model is able to capture the dependency of cell contraction on the stiffness of the mechanical environment and accurately describes the development of an oriented SF network observed in contracting fibroblasts.
Weight regain following sustained weight reduction is predicted by relative insulin sensitivity

Ten moderately obese women (body mass index 34.9 +/- 1.1 kg/m2, mean +/- SEM), had previously been through a 3-month weight loss program followed by 3 months of weight maintenance at the reduced weight. A euglycemic clamp for determination of insulin sensitivity was performed on each subject prior to weight loss, and another at the end of the weight maintenance phase. The mean weight loss for the group was 11.4 +/- 2.2 kg. The women were then seen for follow-up weights 12 months and 18 months after the conclusion of the weight maintenance period. All of the women except one had regained their weight by the time of the 12-month visit. It was found that the amount of weight regained both at 12 months and 18 months was correlated with the change in insulin sensitivity which occurred from the baseline study to after weight loss/maintenance. The data indicate that increased insulin sensitivity following sustained weight loss in obese women predicts weight regain.
On the mechanism for the platinum-catalyzed reduction of rhenium in PtReγ-Al2O3

Abstract The formation of mixed PtRe clusters and of separate clusters of Re and Pt has been studied by temperature-programmed reduction (TPR) for PtRe Al 2 O 3 catalysts of low metal loading. Mixed PtRe clusters are reliably detected by their specific catalytic selectivity for deep hydrogenolysis. Deuterium exchange of cyclopentane is not ensemble-specific and, therefore, useful to normalize the hydrogenolysis rates for extent of reduction and percentage metal exposed. It is concluded that formation of mixed clusters is highest if the Re precursor migrates over the support surface and becomes reduced in contact with a prereduced Pt particle. Hydrogen spillover appears to be limited to this direct contact of the reducible Re species with a Pt cluster. No catalytic effect of Pt on the reduction of Re is observed if the rhenium oxide is immobilized by the formation of a surface compound with γ-Al2O3. Upon hydrolysis of this surface compound, Re oxide regains its surface mobility and can, again, be reduced at significantly lower temperatures.
aflpdat: a collection of r functions for convenient handling of AFLP data

aflpdat is a collection of R functions that facilitates the handling of dominant genotypic data. It converts data from a standard tab-separated table to the input formats of the following programs: arlequin, structure, treecon, paup and hickory. In addition, it calculates the proportion of polymorphic markers in each population, and estimates gene diversity as the average proportion of pairwise differences between individuals with confidence intervals based on bootstrapping across markers. It also produces summary tables of marker frequencies and the presence or absence of markers in each population. aflpdat can be downloaded from http://www.nhm.uio.no/ncb/.
Polycrystalline In2O3 and In2O3/Y2O3 photoanodes

Single crystal In2O3 shows promise as a photoanode for the decomposition of water. Because of various difficulties in the preparation of the single crystal material, two simple techniques were developed for the preparation of polycrystalline In2O3 anodes. One method involves the thermal decomposition of the nitrate while the other utilizes the chemical vapour deposition technique. Voltammograms and photoresponse spectra of these anodes are compared to the single crystal material. Among other observations, it is noted that the quantum efficiencies of the thermally decomposed films are comparable to the single crystal material. It is also shown that the on-set potential can be shifted to more negative values by forming the mixed oxide In2O3/Y2O3.
Less conservative results of delay-dependent H∞ filtering for a class of time-delayed LPV systems

In this paper, we examine the problem of designing parameter-dependent filters for output estimation in an LPV plant that includes a constant state delay. The state-space data are assumed to depend on parameters that are measurable in real-time. We develop linear matrix inequality (LMI) based delay-dependent conditions to guarantee both asymptotic stability and gain performance, and we provide an explicit solution for the filters’ state-space matrices in terms of LMIs. By taking the estimation error into account in the criterion, the designed filters have the capability of tracking the outputs of the plant in the presence of external disturbances. Our technique reduces to delay-independent analysis conditions by relaxing some of the LMI decision variables, and results of previous works are shown to be particular cases of the present work. We examine both memoryless and state delayed filters that include delay terms to reduce conservatism in the design. Illustrative examples are used to demonstrate the pro...
Relative concentrations of molecular and metallic ions in midlatitude intermediate and sporadic‐E layers

[1] A NASA sounding rocket launched from Wallops Island, VA (37.84 N, 75.48 W) on 1 July 2003 at 2:50 EST made the first in situ measurement of the relative concentrations of Fe+, Mg+, O2+, and NO+ within a nighttime intermediate layer below 140 km altitude. Ion composition measurements were made from 80–220 km altitude and included observations of three separate regions having high concentrations of metallic ions: the intermediate layer at 118 km, a sporadic-E layer at 105 km, and a third layer above 160 km altitude. These observations demonstrate that metallic ions may be a significant source of ionization in the nighttime E and F region ionosphere at midlatitudes.
Effects of nitrogen and argon as carrier gases and annealing ambients on the physical properties of PECVD silicon nitride

Abstract Deposition of memory quality plasma-enhanced chemically vapor deposited silicon nitride and post-deposition modification by annealing using argon and nitrogen for carrier gases and annealing ambients have been studied. Although similar memory performance can be achieved, the deposition power and NH 3 /SiH 4 ratio required to do so are functions of the carrier gas used since nitrogen actively participates in the deposition process. Fourier transform infrared, ultraviolet and Auger data reveal that materials deposited with the two gases have similar physical properties although argon films are less dense and lose hydrogen at a higher rate when subjected to annealing. Post-deposition annealing can be used to enhance memory properties of the material provided that the anneal is accomplished at 475°C for 30 minutes. However, enhancement of memory performance by annealling occurs only if the nitride has been deposited using optimum deposition parameters. When annealing is performed in nitrogen. Auger data suggest that nitrogen can be supplied to, or removed from, the material depending on the anneal temperature.
Degree and Sequence of Success as Determinants of Self-Attribution of Ability

Summary Ss performance (N = 70 fourth-grade boys and girls) on a 24-item set of problems was experimentally manipulated to reflect one of four patterns: success on both halves of the set, failure on both halves, failure on the first half and success on the second, and success on the first half and failure on the second. Subsequently, Ss' self-attribution of ability regarding the problems and expectations for future success were assessed. As predicted, results showed a primacy effect: performance on the first half of the test determined attribution of ability and expectations for future performance, with later success or failure having negligible effect.
One Dynamic Pricing Strategy in Agent Economy Using Neural Network Based on Online Learning

This paper examines seller strategies for dynamic pricing in a market for which a seller has finite time horizon to sell its inventory. A dynamic pricing strategy is developed using neural network based on online learning (called SDNN strategy). The SDNN strategy takes in account the dynamics and resulting uncertainties of the market place. The experiments show that the SDNN strategy exhibits superior performance to the other candidate dynamic pricing strategies which of similar computational simplicity and lack of assumptions about the market place.
Patterns of gray matter atrophy in atypical parkinsonism syndromes: a VBM meta-analysis.

Background and Purpose Accurate diagnosis of Atypical Parkinsonian Syndromes (APS) is important due to differences in prognosis and management, but remains a challenge in the clinical setting. The purpose of our meta-analysis was to identify characteristic patterns of gray matter atrophy in Corticobasal Degeneration (CBD), Progressive Supranuclear Palsy (PSP), Multisystem-Atrophy Parkinsonian type (MSA-P), and Idiopathic Parkinson's Disease (IPD). Materials and Methods Whole-brain meta-analysis was performed on 39 published voxel-based morphometry (VBM) articles (consisting of 404 IPD, 87 MSA-P, 165 CBD, and 176 PSP subjects) using the modified Anatomic Likelihood Estimation method. Based on these results, contrast analyses were then utilized to determine areas of atrophy shared by as well as unique to each disorder. Results CBD was characterized by asymmetric gray matter atrophy in multiple cortical regions, while the thalamus-midbrain and insula were predominantly involved in PSP. The striatum and superior cerebellum were affected in MSA-P, while IPD demonstrated an anterior cerebral pattern. Although there was a mild overlap among PSP, CBD, and MSA-P, significant regions of atrophy unique to each disorder were identified, including (1) the superior parietal lobule in CBD (2) putamen in MSA-P (3) insula and medial dorsal nucleus in PSP. Conclusion Our results suggest that there are characteristic patterns of atrophy in APS. Guided by these findings, future studies on the individual subject level may lead to the development of robust imaging biomarkers.
Analytical Approximations in Models of Hysteresis

Decisions made under ongoing uncertainty and costly reversibility entail a range of the state variable where inaction is optimal, which in turn produces hysteresis-permanent effects of temporary shifts. The range is usually defined by non-linear equations that need numerical solutions. In this paper a technique of analytical approximations is developed and applied to two models-menu costs and investment. The resulting explicit solutions help clarify why hysteresis is important even for small irreversibility. In the menu cost model, hysteresis is two orders of magnitude larger than under the Akerlof-Yellen or Mankiw assumptions. When decisions that are costly to reverse are made under conditions of ongoing uncertainty, the optimum policy usually entails a range of inertia. The action should be taken only when the value of the underlying state variable becomes especially favourable, and reversed only when it becomes especially unfavourable. There is an intermediate range over which inaction is optimal. This in turn gives rise to hysteresis. Starting from a value in the range of inertia, if the state variable crosses the action trigger point and then returns to its original level, the action will be taken but not reversed. Thus a temporary change will leave a permanent effect. Numerical solutions for models of irreversible investment show that the range of inaction is remarkably large even when the cost of reversal is small; see Brennan and Schwartz (1985), Constantinides (1986) and Dixit (1989a, b) for examples of this. Unfortunately, the equations tlhat determine the optimum policy are highly non-linear. They do not have analytical solutions. Therefore we lack a clearer and more general understanding of why hysteresis is numerically so important. In this paper I derive analytical approximations for the solutions of more general problems of this kind when the costs of change are small. The idea that small costs of change induce large amounts of inertia has been popularized in the model of Akerlof and Yellen (1985), Mankiw (1985) and others. In these models, second-order small costs of making price changes yield price-stickiness in response to first-order changes in the money supply. This is a simple application of the envelope theorem. But these models are static, and their application to a dynamic reality must assume either permanent shocks or static expectations. When there is ongoing uncertainty, which is rationally expected by the decision-maker, the option value of the status quo enlarges the zone where inaction is optimal. Adding these features to the Mankiw-Akerlof-Yellen (MAY) model, I show that fourth-order small costs of change generate first-order inertia.
Students Say “Let ME Do It!”

Because we were a test site, we have been using the Cataloging Micro Enhancer software since September 1984. Our original goals were to test the software for OCLC and to look for ways to use our M300 Workstation to the best of its ability. Note that we have only one M300 Workstation, on a dedicated line.
Using ecological processes to advance artificial reef goals

The ecological study of natural reef communities has followed a progression from observational/descriptive studies to a more experimental and process-oriented approach. Ironically, most published studies of artificial reefs are observational despite the fact that their manipulative nature lends these reefs to an experimental approach, and despite the potential benefits of an experimental, process-oriented approach to fulfilling their objectives. Most applications of artificial reefs are underpinned by ecological processes ranging from trophic interactions and recruitment to individual physiology and biogeochemical cycling. Examples concerning three goals are discussed; enhancement of fisheries production, ecosystem restoration, and water quality enhancement. These examples illustrate (1) predictions that can be drawn from basic ecological studies of “natural” reef organisms and ecosystems regarding ecological structure, processes, and performance of artificial reefs, and (2) how an experimental ecological approach has been (or could be) utilized to elucidate ecological process and yield specific improvements in the application of artificial reefs to achieve management goals. In fact, answering the “why” and “how” questions addressed by experimental process studies is the only way to improve our success in achieving any sort of ecological engineering objectives. Copyright 2002 Published by Elsevier Science Ltd on behalf of the International Council for the Exploration of the Sea.
Phosphorylation of CD45 by Casein Kinase 2 MODULATION OF ACTIVITY AND MUTATIONAL ANALYSIS

CD45 is a receptor-type protein-tyrosine phosphatase (PTP) that is required for antigen-specific stimulation and proliferation in lymphocytes. This study was designed to determine the nature of specific kinases in lymphocytes that phosphorylate CD45 and to determine the effect of phosphorylation on CD45 PTP activity. A major cytoplasmic lymphocyte kinase that phosphorylated CD45 was identified as casein kinase 2 (CK2) by use of an in-gel kinase assay in combination with immunoprecipitation, immunodepletion, and specific inhibition. Mutational analysis of CK2 consensus sites showed that the target for CK2 was in an acidic insert of 19 amino acids in the D2 domain, and Ser to Ala mutations at amino acids 965, 968, 969, and 973 abrogated CK2 phosphorylation of CD45. CK2 phosphorylation increased CD45 activity 3-fold toward phosphorylated myelin basic protein, and this increase was reversible by PP2A treatment. Mutation of Ser to Glu at the CK2 sites had the same effect as phosphorylation and also tripled the Vmax of CD45. CD45 isolatedin vivo was highly phosphorylated and could not be phosphorylated by CK2 without prior dephosphorylation with phosphatase PP2A. We conclude that CK2 is a major lymphocyte kinase that is responsible for in vivo phosphorylation of CD45, and phosphorylation at specific CK2 sites regulates CD45 PTP activity.
Moving marks: Dynamic histone modifications in yeast

Posttranslational modifications of histones, both in the tails and in the globular cores, alter the functional landscape of chromatin by modulating DNA accessibility and chromatin stability, and by providing an enormous variety of alternative interaction surfaces for trans-acting factors. Complex patterns of acetylation, methylation, phosphorylation, ubiquitylation (and others) result in spatial domains of meaningful chromatin modifications, often referred to as the histone code. Whole genome studies have uncovered striking genome-wide patterns of specific modifications, and individual modifications have been linked to a variety of functional consequences for transcription, replication and repair. A key aspect of the role of histone modifications, however, is their dynamic nature—the precise timing of the addition and removal of specific marks is an essential part of the histone code. This review will highlight examples from budding yeast that illustrate the importance of these dynamic modifications in controlling transcription and repair.
High-resolution electronic spectroscopy of the Ne-OH and Ne·OD A ← X bands

The high-resolution laser-induced fluorescence spectra of the Ne·OH A˜(0,11,1)←X˜(0,00,0) and Ne·OD A˜(0,00,0)←X˜(0,00,0),A˜(0,00,1)←X˜(0,00,0),A˜(0,10,1)←X˜(0,00,0),A˜(0,11,1)←X˜(0,00,0) transitions were obtained. Analyses of these spectra determine precise bond lengths and reveal interesting spin–rotation and parity structure. In the A (0, 1K=0,1, 1) levels of Ne·OH and Ne·OD, the spin–rotation structure is described with the parameter γ, whose magnitude is larger than in the other observed levels of Ne·OH, Ne·OD, and Ar·OH, and Ar·OD. For the K = 1 level an additional term κ is introduced and is found to be an order of magnitude larger than γ. A model based on perturbation theory is proposed and successfully explains the peculiar spin–rotation structure in the A (0, 1K, 1) levels. In addition, a parity-splitting (P-type doubling) for the X˜(0,00,0) level of Ne·OD was determined to be a factor of 10 larger than that in Ar·OD. The parity splitting (K-type doubling) for the A (0, 11, 1) level of Ne·OH is also observed and measured.
NMR studies of an extrahelical cytosine in an A.T rich region of a deoxyribodecanucleotide.

One-dimensional and two-dimensional (2D) nmr experiments were carried out on an oligonucleotide duplex that contains an unpaired cytosine, d(GCGAACAAGCG)·d(CGCTTTTCGC), which will be referred to as the C-bulge decamer. Evidence from one-dimensional nuclear Overhauser effect (NOE) experiments on the exchangeable protons indicates that the unpaired cytosine is extrahelical. This conclusion is also supported by numerous cross-peaks in the 2D NOE spectroscopy (NOESY) spectrum of the nonexchangeable protons. The assignments for all of the resonances, with the exception of the H5′ and H5″ resonances, have been made through the use of 2D NOESY, correlated spectroscopy (COSY), and relayed COSY experiments. The temperature dependence of the C(H6) resonance chemical shifts indicates that the unpaired cytosine shows unusual behavior compared to other cytosines in the duplex. A comparison of chemical shifts for all, the assigned resonances of the duplexes with and without the unpaired cytosine suggests that the majority of the structural perturbation is localized in the A·T tract surrounding the unpaired base. The behavior of the imino resonances as a function of temperature also indicates that the perturbation to the duplex is localized and destabilizes the A·T base pairs adjacent to the unpaired base. © 1993 John Wiley & Sons, Inc.
Validating clustering of molecular dynamics simulations using polymer models

Molecular dynamics (MD) simulation is a powerful technique for sampling the meta-stable and transitional conformations of proteins and other biomolecules. Computational data clustering has emerged as a useful, automated technique for extracting conformational states from MD simulation data. Despite extensive application, relatively little work has been done to determine if the clustering algorithms are actually extracting useful information. A primary goal of this paper therefore is to provide such an understanding through a detailed analysis of data clustering applied to a series of increasingly complex biopolymer models. We develop a novel series of models using basic polymer theory that have intuitive, clearly-defined dynamics and exhibit the essential properties that we are seeking to identify in MD simulations of real biomolecules. We then apply spectral clustering, an algorithm particularly well-suited for clustering polymer structures, to our models and MD simulations of several intrinsically disordered proteins. Clustering results for the polymer models provide clear evidence that the meta-stable and transitional conformations are detected by the algorithm. The results for the polymer models also help guide the analysis of the disordered protein simulations by comparing and contrasting the statistical properties of the extracted clusters. We have developed a framework for validating the performance and utility of clustering algorithms for studying molecular biopolymer simulations that utilizes several analytic and dynamic polymer models which exhibit well-behaved dynamics including: meta-stable states, transition states, helical structures, and stochastic dynamics. We show that spectral clustering is robust to anomalies introduced by structural alignment and that different structural classes of intrinsically disordered proteins can be reliably discriminated from the clustering results. To our knowledge, our framework is the first to utilize model polymers to rigorously test the utility of clustering algorithms for studying biopolymers.
Fractionated feridex and positive contrast: In vivo MR imaging of atherosclerosis

Macrophages have been identified as a critical factor in the pathogenesis of atherosclerosis. Ultrasmall iron oxide particles (USPIOs) have been used to passively target intraplaque macrophages. For dextran-based USPIOs, uptake into macrophages may be modulated by particle size. The aim of the current study was to test the efficacy of fractionated Feridex with respect to macrophage uptake in atherosclerotic rabbits. Fractionation of Feridex resulted in a 15-nm USPIO that exhibited a blood half-life of 15.9 h and liver retention of 6.4%. Blood clearance and liver retention of Feridex was 0.46 h and 60%, following administration of 4.8 mg Fe/kg Feridex. Atherosclerotic rabbits were administered 0.5 or 4.8 mg Fe/kg dosages of either fractionated Feridex or Feridex. MRI was performed at 1.5T over a 24-h time period postinjection. Perls and RAM-11 staining was performed to identify iron deposition. MRI showed a dose-dependent signal loss using conventional gradient echo (GRE) sequences following administration of fractionated Feridex. Even at low dose, significant signal loss was observed that correlated with histology. No signal attenuation or iron deposition was observed in the vessel wall of rabbits administered Feridex. Results of this study suggest that it may be possible to optimize USPIOs for intraplaque macrophage detection.
Characterization of gypsum attenuators for radiotherapy dose modification

Gypsum has significant value as a compensator material for use with high energy x rays in radiation therapy. Compensator thickness may be calculated by using an effective attenuation coefficient (mu eff). Detailed measurements using narrow and broad beam geometry were collected to determine this effective attenuation coefficient as a function of energy (4-15 MV), field size, depth in tissue, and thickness of the compensator. An effective attenuation coefficient relation was defined using a least-square method. It was then determined that extrapolating the broad beam data to a 0 x 0 cm2 field size resulted in a good approximation to the measured narrow beam attenuation coefficient. The variations in surface dose produced by gypsum attenuators were compared to open beam results. For the energies studied, it was determined that the increase in surface dose was acceptable for clinical application.
Exosomes Biogenesis and Potentials in Disease Diagnosis and Drug Delivery

Exosomes were discovered more than 30 years ago. Only recently has their importance been recognized for intercellular communication. Exosomes, with their size ranging from 30 nm to 100 nm, are lipid bilayer nanoparticles and secreted by many different types of cells with versatile functions. Exosomes contain macromolecules and exist in various body fluids, including blood, urine, milk and ascites fluid. Due to their specific property, exosomes are very promising in the fields of disease diagnosis and therapy. Nanotechnology is a great tool that will be helpful in basic research and the application of exosomes. Here, we briefly review the function and potential use of exosomes in nanomedicine.
The digestive system of the lobster, Homarus americanus: III. Removal of foreign particles from the blood by fixed phagocytes of the digestive gland

The digestive gland (midgut gland, hepatopancreas) of the American lobster, Homarus americanus (Decapoda: Nephropidae), is permeated with terminal arterioles of the hepatic artery. Fixed phagocytes associated with the terminal hepatic arterioles removed two types of non-biogenic, foreign particles (carbon particles and latex beads) that were injected into the blood. These cells play an important role in the cell-mediated immunity of lobsters.
Effect of nuclear radiation on the thermal conductivity of polyethylene

Thermal conductivity curves for the 0°C to 170°C temperature region are presented for six irradiated low density polyethylene samples (radiation doses from 0 to 3100 megarads) and one irradiated high density sample (120 megarad dose). In agreement with data in the literature for unirradiated polyethylene, the thermal conductivity values for lightly irradiated polyethylene are found to decrease with increasing temperature in the elevated temperature region where the crystallites begin to melt. Beyond the crystalline melting point, test results for lightly irradiated and crosslinked samples indicate that the thermal conductivity is almost independent of temperature. Although radiation doses of less than 250 megarads produce only small changes in the thermal conductivity, higher radiation doses result in a significant lowering of the conductivity in the room temperature region and an increase of the conductivity at temperatures above the melting point. The decrease in conductivity at low temperatures is considered to be a result of disordering of the crystallites by the radiation, and the increase above the melting point is attributed primarily to radiation induced crosslinking.
A testing method for assessing solder joint reliability of FCBGA packages

Abstract A brittle solder joint at the interface between a solder ball and a substrate metal pad could result in an open joint failure after the solder ball is attached to a motherboard. Existing metrologies, such as ball shear, do not always detect the weak solder joint strength. A peel test for solder joint strength evaluation of substrate was developed. Several problems were observed during the initial stages of the development for this metrology. These included solder bridging and inconsistency of the test results. Solder bridging was reduced by changing the stencil design to have stencil openings that match the solder ball layout and using a jig to align the coupon and substrate while assembling the peel test samples. The paste printing and peeling methods were modified and the coupon quality was carefully monitored to make the sample preparation and testing more consistent. The impact of the physical aging and reflow on the solder joint strength was investigated. It showed that the peel strength did not decrease with physical aging, but did decrease with an increased number of reflows. The peel test results correlated with the performance of the substrates. The substrate with low peel strength had weak solder joints and failed under use conditions. The substrates with high peel strength demonstrated stronger solder joints and performed well under use conditions. The metrology provides a gross check about the presence of brittle solder joints on flip chip ball grid array substrates and is successfully used in monitoring the solder joint strength.
Effect of Succession and Habitat Area on Wandering Spider (Araneae) Abundance in an Experimental Landscape

Abstract Terrestrial communities are strongly affected by habitat area and successional stage. As generalist predators, spiders represent an important community component that may be particularly sensitive to these landscape features. We used pitfall traps to sample ground-dwelling, cursorial spider abundance at 2 successional stages on an experimentally fragmented old-field site in northeastern Kansas. The site, established in 1984, includes replicate habitat patches undergoing secondary succession separated by a matrix of low turf maintained by regular mowing. Spiders were collected from traps located in large (5000 m2) and small (32 m2) patches during 1988 and 1990 (early succession), and 2005 (mid-succession). Total numbers collected were about 20% lower in 2005 than in 1988 and 1990. However, in all 3 yr significantly more spiders were collected by traps in large patches than by traps in small patches. The positive density–area relationship did not differ among years (no significant patch-size by yea...
Understanding vision: students’ use of light and optics resources

We present a qualitative study designed to examine how students construct an understanding of the human eye and vision from their knowledge of light and optics. As would be expected, vast differences are shown to exist between pre- and post-instruction students in terms of not only resource use, but also willingness to transfer their existing knowledge. However, we have found that appropriate scaffolding can facilitate resource activation and guide students to construct an understanding of vision and vision defects.
Worst-case costs for dynamic data element security decisions

The major shortcomings of file security systems which control access decisions at source code translation time are enumerated. An experimental implementation of a system which uses modified operating system I/O routines to distinguish data dependent and independent accesses at execution time is then discussed. CPU overhead costs for different file access restrictions are examined. Preliminary results indicate that cost feasible methods of dynamic selective security may be possible under current operating systems.
Of Mice and Men: Equality and Animals

Can material Egalitarianism (requiring, for example, the significant promotion of fortune) include animals in the domain of the equality requirement? The problem can be illustrated as follows: If equality of wellbeing is what matters, and normal mice are included in this egalitarian requirement, then normal mice have a much stronger claim to resources than almost any human. This is because normal mice have a much stronger claim to resources than almost any human. This is because their wellbeing is much lower than that of normal humans. Thus, equality of wellbeing requires a massive shift of resources away from most humans to mice. This view, however, seems crazy. I explore this problem and propose a solution.
Sparse Encoding of Natural Scents

Natural scents are mixtures of tens to hundreds of individual chemical compounds. While previous studies have investigated how the olfactory bulb responds to simple odorants, how the nose and the brain respond to and interpret complex mixtures is less clear. In a paper in this issue of Neuron, Lin et al. combined gas chromatography and intrinsic signal imaging to examine the responses of individual olfactory bulb glomeruli in the mouse to natural odors and their component parts.
Temporal variations in the relationship between infant mortality and economic status.

Data from a metropolitan aggregate comprising three Ohio cities for the years 1959–61, 1969–71 and 1979–81 reveal some noteworthy variations over time in the nature and magnitude of the traditional inverse association between economic status and infant mortality. This brief paper describes these variations and offers an explanation for the observed temporal changes that relates the influence of medical and infant health care advances to the prevailing overall economic situation.
Adhesive avalanche in covalently bonded materials.

When two strongly interacting materials approach each other, a critical separation can be reached, perhaps several angstroms greater than the bulk separation, when they snap together. This process is known as adhesive avalanche, and is characterized by a structural phase transition from a system possessing two surfaces, to a state in tensile strain with no identifiable surfaces. In this paper, we use the self-consistent pseudopotential method to study the adhesive avalanche between two flat Si(111) surfaces. A detailed description of the evolution of charge densities, total energies, and relaxed structures for five initial separations of the Si(111) surfaces are given. The calculations show that the avalanche event in Si is due to the initiation of covalent-bond formation at a separation of about 2 \AA{} greater than the bulk interplanar spacing, and is driven by localized stresses in the first few surface planes.
Sexual selection and the Y chromosome.

In a very interesting article, Roldan and Gomendio1xRoldan, E.R.S. and Gomendio, M. Trends Ecol. Evol. 1999; 14: 59–62Abstract | Full Text | Full Text PDF | Scopus (48)See all References1 suggest that sexual selection could have favored genes on the mammalian Y chromosome, and that these would include genes on the Y with effects on embryonic growth and tooth size, as well as on spermatogenesis. There are other effects of the Y chromosome on brain and behavior in mice. These include effects of the Y on hippocampal morphology, whole-brain levels of serotonin, open field activity, copulation, aggression and learning2xMaxson, S.C. Behav. Genet. 1996; 26: 471–476Crossref | PubMed | Scopus (48)See all References2. There are sex differences in these brain and behavior traits that might be due to sexual selection3xMaxson, S.C. Biomed. Rev. 1997; 7: 85–90See all References3. Also, the Sry gene (sex determining region on the Y) is expressed in brains of adult mice and humans4xLahr, G. et al. Mol. Brain Res. 1995; 33: 179–182Crossref | PubMed | Scopus (79)See all References, 5xMayer, A. et al. Neurogenetics. 1998; 1: 281–288Crossref | PubMedSee all References; this gene may have effects on the above-mentioned brain and behavioral traits2xMaxson, S.C. Behav. Genet. 1996; 26: 471–476Crossref | PubMed | Scopus (48)See all References2.
Dynamic characterization of contact interactions of micro-robotic leg structures

Contact dynamics of microelectromechanical systems (MEMS) are typically complicated and it is consequently difficult to model all dynamic characteristics observed in time-domain responses involving impact. This issue becomes worse when a device, such as a mobile micro-robot, is not clamped to a substrate and has a complex mechanical structure. To characterize such a contact interaction situation, two walking micro-robot prototypes are tested having intentionally simple structures with different dimensions (21.2 mm × 16.3 mm × 0.75 mm and 32 mm × 25.4 mm × 4.1 mm) and weights (0.16 and 2.7 g). Contact interaction behaviors are characterized by analyzing experimental data under various excitation signals. A numerical approach was used to derive a novel contact model consisting of a coefficient of restitution matrix that uses modal vibration information. Experimental validation of the simulation model shows that it captures various dynamic features of the contact interaction when simulating leg behavior more accurately than previous contact models, such as single-point coefficient of restitution or compliant ground models. In addition, this paper shows that small-scale forces can be added to the simulation to improve model accuracy, resulting in average errors across driving conditions on the order of 2–6% for bounce frequency, maximum foot height, and average foot height, although there is substantial variation from case to case.
Using the Steers-Rhodes (1984) framework to identify correlates of employee lateness

Based on a sample of factory workers, this field study examined correlates of employee lateness. The framework provided by Steers and Rhodes (1984) was used to identify variables related to voluntary and involuntary lateness. Both motivation and ability to be on time were found to be important determinants of lateness as well as joint moderators in explaining lateness. The negative job satisfaction-lateness relationship suggested that a proportion of lateness behavior represented a response to an aversive work environment.
Ultraviolet-Induced Effects on Chloramine and Cyanogen Chloride Formation from Chlorination of Amino Acids

Ultraviolet (UV)-based treatment is commonly used to augment chlorination in swimming pools. However, the effects of combined application of UV254/chlorine on disinfection byproduct (DBP) formation are incompletely defined. To examine this issue, experiments were conducted with amino acids (l-arginine, l-histidine, and glycine) that are representative of those introduced to swimming pools via human body fluids. For each precursor, stepwise experiments were conducted with chlorination and UV254 exposure, with/without post-chlorination. Net formation and decomposition of chloramines and cyanogen chloride (CNCl) were measured for a range of chlorine/precursor (Cl/P) molar ratios and UV254 doses. Substantial production of NH2Cl from l-arginine and l-histidine was observed at Cl/P = 1.0 and 2.0 when post-chlorination was applied to UV254-irradiated samples. These results suggested a mechanism of rapid N-chlorination, followed by cleavage of NH3 by UV254 irradiation. CNCl formation was observed from UV254-irradiated samples of l-arginine and l-histidine when Cl/P = 2.0 and 3.0, as well as from glycine for Cl/P ≤ 1. Structurally related precursor compounds were examined for CNCl formation potential in chlorination/UV experiments. CNCl formation was promoted by UV254 exposure of chlorinated imidazole and guanidine compounds, which suggested that these groups contributed to CNCl formation. The results have implications with respect to the application of chlorine and UV for water treatment in swimming pools and other settings, such as water reuse and advanced oxidation processes.
Cuba's economic and management policy response to the changing global environment

Amongst the various countries in transition, Cuba is pursuing a path of adjustment in which it is striving to maintain the basic social achievements of its revolution. The article describes, first, Cuba's development in the period from 1960 to the mid 1980's; second, the impact of the changing international situation thereafter on the Cuban economy; and third, the way in which Cuba has responded to the latter, specifically its efforts to promote diversified foreign trade and investment and to create a new management culture supportive of the latter. Against this background, an assessment is made of ongoing institutional reforms in the exporting sector of Cuba's state enterprises and planning system. US embargo notwithstanding, Cuba is receiving significant international support for the latter, especially from the UN system. The article finally assesses the prospects for the Cuban economy, in a situation of increasing difficulty. Conclusions range over a number of issues that arise from Cuba's strategy for survival and renewed growth: (i) the emerging contradictions within its overall strategy, particularly the split between the centrally-planned and controlled domestic market and the much freer exporting and foreign exchange earning sectors; (ii) the ability of the population to tolerate the adjustment costs and deprivations in the short term; (iii) international competition with a number of other countries for foreign investment, particularly Pharmaceuticals; (iv) some of the strategic risks inherent in the selective and gradualist approach of Cuba and its ability to turn around the economy in time to enable it to survive; (v) the ability of the overall system to move quickly forward from basic management training to structural change in what might be the enabling policy and institutional environment. In confronting these challenges, the article also stresses (i) the adaptability of Cuban managers who have shown themselves highly retrainable to play new roles in the global economy; (ii) the considerable resource endowments of Cuba, including abundant human capital and investment in scientific and technological research and development, its location advantages and its stability and determination.
B.A.I.L.A. - a Latin dance randomized controlled trial for older Spanish-speaking Latinos: rationale, design, and methods.

Abstract Background Physical activity (PA) has documented health benefits, but older Latinos are less likely to engage in leisure time PA than older non-Latino whites. Dance holds a promise as a culturally appropriate form of PA that challenges individuals physically and cognitively. This paper describes a randomized controlled trial that will test the efficacy of BAILAMOS©, a 4-month Latin dance program followed by a 4-month maintenance program, for improving lifestyle PA and health outcomes. Methods Older adults (n = 332), aged 55+, Latino/Hispanic, Spanish speaking, with low PA levels, and at risk for disability will be randomized to one of two programs, a dance program or health education control group. BAILAMOS© is a 4-month program that meets two times per week for one 1 h per session. Dance sessions focus on instruction, including four styles of dance, and couples dancing. Bi-monthly ©Fiestas de Baile© (dance parties) are also included, in which participants dance and practice what they have learned. Monthly 1-hour discussion sessions utilize a Social Cognitive framework and focus on knowledge, social support, and self-efficacy to increase lifestyle PA. The health education control group will meet one time per week for two 2 h per session. Outcomes Primary outcomes including PA changes and secondary outcomes including self-efficacy, physical function, cognitive function, and disability will be assessed at baseline, 4, and 8 months. It is hypothesized that PA, self-efficacy, physical function, cognitive function, and functional limitations and disability scores will be significantly better in the BAILAMOS© group at 4 and 8 months compared to the control group.