cssi/SciSciGPT-SciSciNet huggingface dataset:
Mixed Polymer Brush-Grafted Particles: A New Class of Environmentally Responsive Nanostructured Materials

Mixed polymer brush-grafted particles, in which two distinct polymers are randomly or alternately immobilized by one end via a covalent bond on the surface of core particles with sufficiently high grafting densities, represent a new, intriguing class of environmentally responsive nanostructured hybrid materials. The two end-tethered polymers can undergo spontaneous chain reorganization in response to environmental variations, rendering particles adaptive surface properties and different colloidal behavior. This Perspective is intended to review recent exciting progress on the synthesis, responsive properties, self-assembled structures, and applications of mixed brush-grafted particles with a spherical core radius Rcore significantly larger than, comparable to, and smaller than the root-mean-square end-to-end distances (⟨Rrms⟩) of grafted polymers. The critical yet unsolved issues in the phase morphology of mixed homopolymer brushes and the hierarchical self-assembly of mixed brush-grafted particles are di...
Not-So-Pseudo a Substrate: Acm1-Mediated Inhibition of the APC

In a recent issue of Molecular Cell, Enquist-Newman et al. (2008) demonstrate that Acm1 is ubiquitinated by APCCdc20. By contrast, the high-affinity interaction between Acm1 and APCCdh1 renders it a poor substrate, but a specific inhibitor, of the APCCdh1 complex.
Explorative Assessment of Internet Hacking: An Agent-Based Modeling Approach

AbstractInternet hacking is fast becoming a significant threat not only to businesses, but government entities, online communities, and individual Internet users as well. We have built an agent-based model (ABM) to study the dynamics of Internet hacking. Several factors that impact the adoption of Internet hacking are evaluated. Through ABM simulations we explore the interactions of various types of Internet users along with their hacking propensity and the resulting hacking trends. The simulations point to several interesting outcomes. For instance, the hacking trend is greatly affected by the quantum of law enforcement and by the influence of hackers on normal users. On the other hand, the number of initial hackers and the degree of interaction do not appear to be significant factors. In addition, the results of the simulation illustrate the impact of the mass media and of “hacking websites” on Internet hacking trends.
An efficient, block-by-block algorithm for inverting a block tridiagonal, nearly block Toeplitz matrix

We present an algorithm for computing any block of the inverse of a block tridiagonal, nearly block Toeplitz matrix (defined as a block tridiagonal matrix with a small number of deviations from the purely block Toeplitz structure). By exploiting both the block tridiagonal and the nearly block Toeplitz structures, this method scales independently of the total number of blocks in the matrix and linearly with the number of deviations. Numerical studies demonstrate this scaling and the advantages of our method over alternatives.
Relationship of Hypoxia to Arrhythmia and Cardiac Conduction Hemorrhage

The relationship between hypoxia, arrhythmia, and hemorrhage of the conducting system was studied in the experimental laboratory by rendering several different groups of rats and dogs hypoxic, and by the histological examination of the area of the atrioventricular node and bundle of His in sections obtained from the hearts of these animals. Sixty-one per cent of rats aged two weeks or older developed arrhythmias and had hemorrhage. None of 10 baby rats presented changes when submitted to the same type of experiment. Hemorrhage was present in only 40 per cent of asphyxiated dogs and in 40 per cent of the dogs that were made hypoxic during cardiopulmonary bypass; 75 per cent of dogs which underwent total mitral valvular replacement and expired in acute pulmonary edema 3 to 10 days postoperatively presented a similar type of lesion. In most cases, the administration of oxygen sufficed to reverse the electrocardiographic changes back to normal. Hypoxia is suggested as the primary cause for these changes, on t...
Insulin-like Growth Factors Reverse or Arrest Diabetic Neuropathy: Effects on Hyperalgesia and Impaired Nerve Regeneration in Rats

Diabetic neuropathy is a debilitating disorder whose causation is poorly understood. A new theory proposes that neuropathy may arise as a consequence of loss of neurotrophic insulin-like growth factor (IGF) activity due to diabetes, superimposed on a slow continual loss due to aging. The prediction that IGF-I and IGF-II gene expression are reduced in diabetic nerves was recently tested and validated. Here we tested the prediction that IGF administration can prevent or reverse diabetic sensory neuropathy. Subcutaneous infusion of IGF-I or IGF-II, but not vehicle, halted (P < 0.01) the progression of hyperalgesia in streptozotocin-diabetic rats. Moreover, impaired sensory nerve regeneration was partially reversed within 2 weeks after treatment of diabetic rats with IGFs (P < 0.01). Impaired regeneration could also be prevented by daily subcutaneous IGF injections. The low replacement doses of IGFs were effective despite unabated hyperglycemia and weight loss. These results show that IGF replacement therapy can reverse or prevent diabetic sensory neuropathy independently of hyperglycemia or weight loss.
Dynamic compression of a zirconium-based bulk metallic glass confined by a stainless steel sleeve

Anvil-on-rod impact experiments were performed on zirconium-based bulk metallic glass rods with stainless steel confinement sleeves. High-speed photography and velocity interferometry were used to obtain qualitative and quantitative information about the transient deformation and failure response of the impacted specimens. Fracture surfaces of the recovered, impacted specimens were analyzed using scanning electron microscopy. Numerical simulations were also used to elucidate the deformation and failure response and better understand the effects of the altered stress states caused by the confinement sleeve.
Measurement of long-range forces on a single yeast cell using a gradient optical trap and evanescent wave light scattering

Abstract The long-range equilibrium and viscous interaction forces between a single Candida albicans cell and a flat surface have been measured using a gradient optical trap as a force transducer and evanescent wave light scattering (EWLS) to determine the separation distance. In this technique the trapped cell is probed against the surface by moving the focal point of the optical trap, the equilibrium force is determined by the deflection of the most probable cell position from the trap center, and the viscous forces are determined from the relaxation time of the Brownian fluctuations of the cell in the trap. At low electrolyte concentrations (0.5 mM NaCl) where double layer repulsion was anticipated to be the dominant interaction, equilibrium force–distance profiles for yeast cells and similarly sized polystyrene microspheres on glass surfaces both showed good agreement with predictions of DLVO theory. Also, viscous drag profiles at larger separation distances where interaction forces were small agreed well with Stokes flow predictions. These results appear to validate the technique for use with spherical yeast cells and other bioparticles of similar size. This force measurement methodology therefore provides a complementary alternative to atomic force microscopy for direct force measurement with much greater sensitivity for studying interaction between yeast and surfaces.
Gender, informal social support networks, and elderly urban African Americans

Abstract Using data derived from a semi-longitudinal interview study of 45 urban, community-living African Americans aged 65 and over, this paper explores gender differences in informal social support. Women were found to have significantly larger, more extended informal social support networks than men. Adult children, daughters in particular, were key figures in the networks, especially for women. Men, especially men married to women who were not the mothers of their children, have small and vulnerable networks. The size and composition of informal social support networks were stable over a six month period, despite some change in the health and physical functioning of respondents. Informal social support networks existed long before such networks needed to be mobilized for caregiving purposes, and such networks arose in response to socioeconomic and affiliative needs across the entire lifespan rather than just in response to health or physical function needs in late life. Societal marginalisation of Black men throughout their life has had profound effects on their access to informal social support in late life.
An improved method for obtaining thermal titration curves using micromolar quantities of protein

Abstract Two simple modifications of a commerclally available microcalorimeter allow rapid and accurate equilibration of sample with titrant and result in increased sensitivity. The modifications permit the rapid equilibration of the reaction vessel vapor space with solvent vapor and unambiguous determination of the temperature difference between the thermostat and the contents of the reaction vessel. A procedure is described for performing a thermal titration under conditions in which the system is undergoing a continuous thermal drift. The procedure is used to determine the standard enthalpy and free energy changes for the binding of ADP to bovine liver glutamate dehydrogenase. Only 0.3 μmol of protein sample was required. The observed values (Δ H ot = −13.0 ± 0.7 kcal mol −1 , Δ G ot = −7.4 kcal mol −1 ) agree within 5% of the values determined by S. Subramanian, D. C. Stickel, and H. F. Fisher (1975, J. Biol. Chem. 250 , 5885–5889).
Breast cancer screening by Asian-American women in a managed care environment

Abstract Context: Cross-sectional surveys show that Asian-American women are less likely to have had screening mammograms. Objective: To prospectively assess mammography screening by Asian-American women in a program with mailed recommendations and no out-of-pocket costs. Design: Two prospective cohort studies. Setting: A nonprofit health care system where women members ≥ 40 years old are surveyed for breast cancer risk factors and enrolled into a screening program on survey completion. Participants: Program enrollment—All Asian-American women identified through a compilation of Asian surnames (Chinese, Japanese, Vietnamese, and Korean) and a random sample of 2000 women with non-Asian surnames, who were mailed a survey from May 1988 to April 1995. Mammogram participation—All Asian-American women and a random sample of 3000 women with non-Asian surnames, enrolled in the screening program and were mailed a first recommendation for screening from May 1988 to April 1994. Main Outcome Measures: Odds of program enrollment and mammogram use within one year (participation) by Asian-American women compared to non-Asian controls. Results: Compared to controls, Asian-American women were less likely to enroll in Breast Cancer Screening Program (BCSP) (odds ratio 0.53; 95% CI 0.43, 0.64). In aggregate, Asian-American women had similar mammogram participation rates. Among older Chinese-American women participation was lower compared to controls (odds ratio 0.66; 95% CI 0.44, 0.97). Conclusion: Participation in mammography screening (program enrollment and participation) by Asian-American women was not necessarily enhanced by the removal of financial barriers. Variations of screening behavior among Asian-American women may be obscured when analyzed in aggregate.
Hybrid Simulation with Improved Operator-Splitting Integration Using Experimental Tangent Stiffness Matrix Estimation

Improved numerical integration procedures are essential for the extension of hybrid numerical and experimental simulation to large and complex structural systems. While implicit integration algorithms are widely used in pure numerical simulations for their superior stability and accuracy, their direct application to hybrid simulation has been partially limited by difficulties in estimating the tangent stiffness matrix of multi-degree-of-freedom experimental substructures. Current applications of hybrid simulation using integrators with improved stability have mostly resorted to methods that are noniterative or utilize the initial stiffness matrix for iterative corrections. To improve the accuracy of integration procedures for hybrid simulation, a new method for online estimation of experimental tangent stiffness is proposed. The stiffness estimation procedure is tailored for fast online applications by transforming the measurements into a coordinate system, which reduces the number of unknown stiffness coefficients that need to be updated during the simulation. The updated experimental stiffness matrix is used in a modified operator-splitting integration scheme to improve the accuracy of hybrid simulations with highly nonlinear experimental substructures. The application and effectiveness of the proposed approach is demonstrated through hybrid simulations with multi-degree-of-freedom experimental substructures.
Stress from re-immersion of partially dried gel

Abstract When liquid evaporates from a gel, capillary tensile pressure (suction) develops in the liquid and corresponding compressive forces are imposed on the solid network, leading to contraction. At any point up to the time when shrinkage stops, the pores remain full of liquid. If, during that stage, the gel is immersed into liquid, the capillary pressure is suddenly relieved at the surface of the body, so the compressive forces on the network are eliminated and the network tends to expand elastically. The expansion of the surface creates compressive stresses near the surface and tensile stresses inside the body. These stresses can be great enough to cause cracking. In this paper, the stresses caused by re-immersion of a partially dried cylinder of gel are analyzed. The stresses are shown to be greatest at the axis of the cylinder, where fracture is observed to originate. By reducing the pressure at the surface slowly (as by exposing the gel to a humid atmosphere), the stresses can be kept low, so that the partially dried gel can be safely re-immersed.
A Note on Loss Aversion and Futures Hedging

This note examines the effect of loss aversion on the futures trading behavior of a short hedger. Using a modified constant-absolute-risk-aversion utility function, I show that loss aversion has no effect in an unbiased futures market. It has different, predictable impacts when the futures market is in backwardation or contango. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21: 681–692, 2001
A versatile, bar-coded nuclear marker/reporter for live cell fluorescent and multiplexed high content imaging.

The screening of large numbers of compounds or siRNAs is a mainstay of both academic and pharmaceutical research. Most screens test those interventions against a single biochemical or cellular output whereas recording multiple complementary outputs may be more biologically relevant. High throughput, multi-channel fluorescence microscopy permits multiple outputs to be quantified in specific cellular subcompartments. However, the number of distinct fluorescent outputs available remains limited. Here, we describe a cellular bar-code technology in which multiple cell-based assays are combined in one well after which each assay is distinguished by fluorescence microscopy. The technology uses the unique fluorescent properties of assay-specific markers comprised of distinct combinations of different ‘red’ fluorescent proteins sandwiched around a nuclear localization signal. The bar-code markers are excited by a common wavelength of light but distinguished ratiometrically by their differing relative fluorescence in two emission channels. Targeting the bar-code to cell nuclei enables individual cells expressing distinguishable markers to be readily separated by standard image analysis programs. We validated the method by showing that the unique responses of different cell-based assays to specific drugs are retained when three assays are co-plated and separated by the bar-code. Based upon those studies, we discuss a roadmap in which even more assays may be combined in a well. The ability to analyze multiple assays simultaneously will enable screens that better identify, characterize and distinguish hits according to multiple biologically or clinically relevant criteria. These capabilities also enable the re-creation of complex mixtures of cell types that is emerging as a central area of interest in many fields.
Reevaluation of mortality risks from leukemia in the formaldehyde cohort study of the National Cancer Institute

Abstract Objective. To determine whether the National Cancer Institute’s (NCI) recent suggestion of a causal association between formaldehyde exposure and mortality from leukemia and myeloid leukemia (ML) is robust with respect to alternative characterizations and categorizations of formaldehyde exposure and to alternative methods of data analysis. Methods. The original authors provided the cohort data. We computed US and local county rate-based standardized mortality ratios (SMRs) and internal cohort rate-based relative risks (RR) by categories of four formaldehyde exposure metrics (highest peak, average intensity (AIE), cumulative, and duration), using both NCI categories and an alternative categorization based on tertiles of deaths from all leukemia among exposed subjects. For highest peak exposure, we computed RRs by the duration of time worked in the highest peak category and the time since highest peak exposure. For AIE, we computed RRs by the duration of exposure and the time since first exposure. Results. Our external comparisons revealed that the elevated leukemia and ML RRs and associated trends reported by NCI for highest peak and AIE occurred because null (or slight) to moderate mortality excesses were compared with statistically significant baseline category deficits in deaths. Our alternative categorization of AIE yielded leukemia and ML SMRs close to 1.0 in the highest exposure category, and revealed weaker evidence of a trend in RRs for leukemia and ML. We corroborated NCI’s finding of no association for cumulative and duration of formaldehyde exposure. We found no consistent evidence that leukemia or ML risks increased with increasing duration of time spent in a given highest peak exposure (or for AIE, duration of exposure in a given AIE category). We also found no consistent evidence that leukemia or ML risks were greater in the more relevant shorter (less than 20 years) versus longer (20+ years) periods of time from the first highest peak exposure (or for AIE, first exposure). Conclusions. Our reanalysis provided little evidence to support NCI’s suggestion of a causal association between formaldehyde exposure and mortality from leukemia and ML. NCI’s key findings for highest peak exposure and AIE do not adequately account for the inordinately large deficits in deaths in the categories used as the baselines for internal rate-based RRs. The NCI findings also do not adequately account for the duration of time subjects spent in the highest peak category (or for AIE, duration of exposure) or the time since their first peak exposure (or for AIE, time since first exposure). Our finding that NCI’s suggestion of a causal association is not robust with respect to alternative categorizations of formaldehyde exposure and methods of data analysis casts considerable additional uncertainty regarding the validity of this suggested association.
Binding of vanadium (IV) to the phosphatase calcineurin

X-band electron spin resonance spectroscopy was used to study the binding of vanadium (IV), or vanadyl, to the brain serine/threonine phosphatase-2B, calcineurin. Spectra were determined on frozen solutions of vanadyl and calcineurin at pH 7.4 in the presence of 20% (v/v) glycerol. The binding of vanadyl to the enzyme was established, and the data suggested the presence of two classes of sites, the higher affinity class of which contained two binding sites for vanadyl. The calcium-binding B subunit of the heterodimeric protein was also shown to bind vanadyl. The holoprotein appeared to be stabilized by vanadyl, and vanadyl enhanced enzymatic activity when assayed with or without calmodulin in the absence of calcium.
Efficient Loop-Level Parallelism in ADA

Parallelism in scientific applications can most often be found at the loop level. Although Ada supports parallelism via the task construct, its coarseness renders it unsuitable for this light-weight parallelism. In this work, we propose Ada constructs to achieve efficient loop-level parallelism in ANSI-Ada. This is accomplished in two steps. First, we present an idiom that allows the specification of light-weight tasks. Second, we give an efficient implementation of this idiom (for a variety of shared memory machines) that is considerably more efficient than a standard Ada task. In addition, we present an idiom that makes the fetchenspaceandenspaceadd synchronization primitive available at the Ada level. Our implementation of this idiom is more efficient in both time and space than previous results. In addition to providing universal synchronization, using fetchenspaceandenspaceadd simplifies program analysis (e.g. proving the absence of race conditions in the implementation of a parallel algorithm). Since all these idioms are written in standard Ada, they maintain the portability that is central to the mandated uses of the language.
The Effect of Smoking on Individuals With Minimal Periodontal Destruction

Recent studies have demonstrated that smoking is associated with periodontal destruction. The majority of these studies have focused on periodontal disease groups with moderate or severe periodontal destruction. Additionally, there have been few reports investigating the relationship between smoking and gingival recession. The goal of this report was to investigate the effect of smoking on periodontal destruction and recession in subjects with minimal or no interproximal attachment loss. This is a cross-sectional study of 142 non-smoking subjects and 51 smoking subjects. Subjects could have no more than one tooth with a site of interproximal attachment loss > or =2 mm. Subjects could, however, have attachment loss associated with recession. For three different methods of summarizing attachment loss measurements at a subject level, including average attachment loss, percentage of teeth with one site of 2 mm of attachment loss, and the percentage of teeth with one site of 5 mm of attachment loss, smoking subjects had approximately twice as much attachment loss than their non-smoking counterparts. Smoking subjects also had significantly greater recession (P < 0.05) [0.056+/-0.017 mm] than non-smoking subjects (0.025+/-0.005 mm). Recession sites occurred primarily on the facial surface of maxillary molars and bicuspids and mandibular central incisors and bicuspids. The results suggest a strong association between smoking and both attachment loss and recession in subjects who have minimal or no periodontal disease.
Transformation of catecholaminergic precursors into glucagon (A) cells in mouse embryonic pancreas.

Abstract In embryonic mice, the catecholamine biosynthetic enzyme tyrosine hydroxylase [L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2] can be visualized immunocytochemically in a population of cells in epithelial cords of the developing pancreas. These embryonic catecholamine cells, first seen by day 11, are large and vacuolated and have a folded nuclear membrane. One day later, at day 12, glucagon is first detected immunocytochemically in pancreatic cells similar in location and morphology to the embryonic catecholamine cells. By use of a method for detecting both antigens in the same cell, both the hydroxylase and glucagon can be visualized between day 12 and day 14 in 10-40% of stained cells. From day 14, the number of cells stained for hydroxylase decreases; they cannot be detected after day 18. In contrast, the cells containing glucagon increase during development and persist throughout life. Endocrine cells of the embryonic pancreas also contain dopa decarboxylase but not dopamine-beta-hydroxylase or phenylethanolamine-N-methyl transferase. In adult mice, small cells containing tyrosine hydroxylase but differing in location and morphology from the embryonic catecholaminergic cells are seen in pancreatic islets. The adult catecholaminergic cells never store glucagon. We suggest that adult glucagon (A)-containing cells arise from transformation in situ of cells that transiently express a catecholaminergic (probably dopaminergic) phenotype. These results suggest that one class of peptidergic cells may arise from transformation of an aminergic precursor.
Support Recovery for the Drift Coefficient of High-Dimensional Diffusions

Consider the problem of learning the drift coefficient of a $p$ -dimensional stochastic differential equation from a sample path of length $T$ . We assume that the drift is parametrized by a high-dimensional vector, and study the support recovery problem when both $p$ and $T$ can tend to infinity. In particular, we prove a general lower bound on the sample-complexity $T$ by using a characterization of mutual information as a time integral of conditional variance, due to Kadota, Zakai, and Ziv. For linear stochastic differential equations, the drift coefficient is parametrized by a $p\times p$ matrix that describes which degrees of freedom interact under the dynamics. In this case, we analyze a $\ell_{1}$ -regularized least squares estimator and prove an upper bound on $T$ that nearly matches the lower bound on specific classes of sparse matrices.
Developing Materials for a Digital Library Gallery

This essay explores how scholars working on “Pluralism and Adaptation in the Islamic Practice of Senegal and Ghana,” a National Endowment for the Humanities (NEH) Collaborative Research project, partnered with a digital humanities center to create freely available online digital collections to enhance research, teaching, and learning about West African Islam. By looking closely at the development of one of these online galleries, Professor David Robinson’s “Failed Islamic States in the Senegambia,” we examine how materials are prepared for this type of web presentation. Specifically, the essay reviews the efforts of subject experts in describing and cataloging multimedia collections so that users understand the context in which the primary source materials were created, as well as the overarching purpose of the digital collections. We also describe the technology and standards used for storing, retrieving, and displaying interviews, documents, and images in this collection. In short, this essay provides insight into the processes and challenges by which we transform field and archival research data into contextualized web resources useful for learning about and researching Africa and Islam.
Melatonin-induced suppression of gonadotropin titers in male golden hamsters: Effect on gonadal feedback mechanisms☆

Abstract Daily subcutaneous injections of melatonin cause testicular regression and a decline in circulating gonadotropin levels in male hamsters maintained on long photoperiods. We examine here if a reduction in gonadotropin levels also occurs in castrates administered melatonin and if melatonin-regressed hamsters respond to castration with an increased release of pituitary gonadotropins — a typical “castration response.” Groups of intact and castrated male hamsters maintained on a photoperiod of LD 14:10 received subcutaneous injections of 15 ug melatonin/day. Controls received vehicle only. After 7 weeks of injections the intact males were castrated. All animals were sacrificed a few days later and serum was assayed for gonadotropin titers. Melatonin injections caused a marked decline in serum gonadotropins in castrates and in intact males also caused testicular regression. In the latter, no “castration response” was observed upon removal of the testes. Thus, daily injections of melatonin depress serum gonadotropins in castrate and intact males and block the castration-associated rise in circulating gonadotropins in the latter.
Radioautography of multiple isotopes using color negative films.

Abstract An autoradiographic method using color negative films is described which permits differentiationof common radioisotopic decays ( 3 H, 14 C, 35 S, 32 P, and 125 I) according to the volor of the radiographic image produced. The method allows simultaneous quantitation of 3 H and any one of the other isotopes. By this means the need for multiple films or exposures, registration of images, and selective attenuation of the decay particles is eliminated.
Prostanoid Receptors of Murine NIH 3T3 and RAW 264.7 Cells STRUCTURE AND EXPRESSION OF THE MURINE PROSTAGLANDIN EP4 RECEPTOR GENE

Prostaglandin endoperoxide H synthase-1 (PGHS-1) is expressed constitutively in murine NIH 3T3 cells and RAW 264.7 cells. PGHS-2 is inducibly expressed in these cells following stimulation with serum or bacterial lipopolysaccharide (LPS), respectively. Reverse transcription-polymerase chain reaction (RT-PCR) analysis established that a variety of G protein-linked and peroxisomal proliferator-activated prostanoid receptors are expressed in both of these cell types. The levels of the EP2 and EP4 prostaglandin E2 (PGE2) receptors and the prostaglandin I2 receptor were changed in these cells by serum or LPS stimulation. Quantitative RT-PCR indicated that the mRNA for the murine EP4 receptor, the butaprost-insensitive PGE2 receptor that couples to Gs, increases 1.5-3-fold in response to serum (NIH 3T3) or LPS (RAW 264.7) with a time course approximating the induction of PGHS-2 expression. To study expression of the EP4 receptor we isolated the mouse EP4 receptor gene; the gene is 10 kilobase pairs (kb) in length and, like other known prostanoid receptor genes, contains three exons and two introns. The first intron is 0.5 kb and is located 16 base pairs (bp) downstream of the translational start site. This is a different location than that of the first introns of other prostanoid receptor genes. The second intron is located immediately following the sixth transmembrane domain at the same position as the second intron of the thromboxane A2 receptor, prostaglandin D2 receptor, prostaglandin I2 receptor, and one of the PGE2 (EP1) receptor genes. A major transcriptional start was detected at -142 bp upstream of the translational start. There are a variety of putative cis-acting elements within 1.5 kb upstream of the translational start site and within the first intron. Promoter analyses of the EP4 receptor gene promoter in RAW 264.7 cells indicated that there is a constitutive negative regulatory region between -992 and -928 bp, a constitutive positive region between -928 and -554 bp, and an LPS/serum-responsive region between -554 and -116 bp.
Differences between direct and remote plasma enhanced CVD

Abstract This paper distinguishes between two different approaches to PECVD: (a) DIRECT PECVD in which: (a) all of the gas phase reactants are simultaneously plasma excited; and (b) the substrate is immersed in the plasma; and (b) REMOTE PECVD in which (a) only one the reactant gases (and generally, a diluent) are plasma excited; and (b) the substrate is outside of the plasma.
Handwritten zip code recognition using an optical radial basis function classifier

We describe a new optical architecture for the realization of distance-based classifiers and in particular, radial basis function classifiers. This new system uses spatial multiplexing to improve computation speed while simple parallel postprocessing electronics are used to provide on-line learning in the optical neural network. This architecture is compared with a previous optical system which realized a radial basis function classifier in the solution of the
Quantitative evaluation of noise reduction strategies in dual-energy imaging

In this paper we describe a quantitative evaluation of the performance of three dual-energy noise reduction algorithms: Kalender's correlated noise reduction (KCNR), noise clipping (NOC), and edge-predictive adaptive smoothing (EPAS). These algorithms were compared to a simple smoothing filter approach, using the variance and noise power spectrum measurements of the residual noise in dual-energy images acquired with an a-Si TFT flat-panel x-ray detector. An estimate of the true noise was made through a new method with subpixel accuracy by subtracting an individual image from an ensemble average image. The results indicate that in the lung regions of the tissue image, all three algorithms reduced the noise by similar percentages at high spatial frequencies (KCNR=88%, NOC=88%, EPAS=84%, NOC/KCNR=88%) and somewhat less at low spatial frequencies (KCNR=45%, NOC=54%, EPAS=52%, NOC/KCNR=55%). At low frequencies, the presence of edge artifacts from KCNR made the performance worse, thus NOC or NOC combined with KCNR performed best. At high frequencies, KCNR performed best in the bone image, yet NOC performed best in the tissue image. Noise reduction strategies in dual-energy imaging can be effective and should focus on blending various algorithms depending on anatomical locations.
Perspectives on wildfire in the humid tropics

Over the last 30 years our understanding of the effects of wildfire on tropical forest environments has expanded enormously. To introduce readers to this topic, we asked Christopher Uhl to recount some of his experiences studying fire in the humid tropics. His account sets the stage for four short contributions that compose this installment of Issues in International Conservation.
Volatile composition of Gutierrezia sarothrae (Broom Snakeweed) as determined by steam distillation and solid phase microextraction

Abstract Volatiles of Gutierezia sarothrae (broom snakeweed, snakeweed) were isolated from ground, composite tissues by steam distillation and by solid phase microextraction (SPME), then separated and analyzed by gas chromatography with mass spectral and flame ionization detection. Compounds detected varied in quantity between isolation protocols. In the oil, cryptone (6.4%) and β-eudesmol (5.9%) were the only compounds comprising more than 5% of the chromatographic peak area. In samples prepared by solid-phase microextraction, limonene (10.4%), β-pinene (9.6%), β-eudesmol (8.0%), sabinene (7.8%), cryptone (6.5%), α-pinene (5.5%) and o-cymene (5.2%) accounted for 53% of the extracted volatiles. The results revealed a complex volatile composition from which unique compounds may still be identified.
Conformational changes in bacteriorhodopsin studied by infrared attenuated total reflection.

We report on a new method based on Fourier transform infrared (FTIR)-difference spectroscopy for studying the conformational changes occurring during the photocycle of bacteriorhodopsin. Previous studies have been made by measuring the absorbance of an infrared (IR) beam transmitted through a thin hydrated purple membrane film. In contrast, the present study utilizes the technique of attenuated total reflection (ATR). Purple membrane is fixed on the surface of a germanium internal reflection crystal and immersed in a buffer whose pH and ionic composition can be varied. Measurements of the amide I and II absorbance with light polarized parallel and at 45 degrees to the crystal surface reveals that the membrane is highly oriented. An ATR-FTIR-difference spectrum of the light to dark (bR570 to bR548) transition is similar but not identical to the transmittance FTIR-difference spectrum. This disagreement between the two methods is shown to be due in the ATR case to the absorption of transition moments oriented predominantly out of the membrane plane. Raising the pH of La3+ substituted purple membrane films from 6.8 to 8.0 slows the M-decay rate sufficiently so that a bR570 to M412 difference spectrum can be obtained with steady state illumination at room temperature. A comparison of this difference spectrum with that obtained at -23 degrees C using the transmittance method reveals several changes that cannot be attributed to out-of-plane transition moments.(ABSTRACT TRUNCATED AT 250 WORDS)
In the Light of Evolution IV: The Human Condition

The year 2009 marked the 200th anniversary of Charles Darwin’s birth and the 150th anniversary of his most influential publication. Darwin transformed the biological sciences in much the same way that Nicolaus Copernicus, Galileo Galilei, and Isaac Newton, centuries earlier, transformed the physical sciences—by demonstrating that the universe operates according to natural laws that fall within the purview of rational scientific inquiry. In 1543, Copernicus published De Revolutionibus Orbium Celestium (“ On the Revolutions of the Celestial Spheres ”) that challenged conventional wisdom that the Earth was the center of creation and instead promoted the idea that natural laws govern the motion of physical objects in the universe. In 1859, in On the Origin of Species (4), Darwin developed the equally revolutionary concept that a natural but nonrandom process—natural selection—yields biological adaptations that otherwise can give the superficial impression of direct intelligent craftsmanship. Actually, Darwin barely mentioned Homo sapiens in On the Origin of Species, cautiously stating only that “much light will be thrown on the origin of man and his history.” More than a decade later, however, Darwin addressed human evolution at considerable length in The Descent of Man and Selection in Relation to Sex (5) wherein can be found many thoughtful passages, such as, “Man may be excused for feeling some pride at having risen, though not through his own exertions, to the very summit of the organic scale; and the fact of his having thus risen, instead of having been aboriginally placed there, may give him hope for a still higher destiny in the distant future.” Of course, much has been learned about humanity’s evolutionary origins and biological conditions since Darwin’s time, not least from the evidence of paleontology, comparative vertebrate biology, and genomics. An emerging field known as “anthropogeny” (6) seeks to understand the evolutionary origins … [↵][1]1To whom correspondence should be addressed. E-mail: javise{at}uci.edu. [1]: #xref-corresp-1-1
Measurements of Local Skin Friction in a Microbubble Modified Turbulent Boundary Layer

Local skin-friction reductions have been measured using an array of flush-mounted hot-film probes in a microbubble-modified, zero-pressure-gradient, turbulent bounddary layer. The results of earlier integrated skin-friction measurements, that showed the reduction to be a function of plate orientation, gas-flow rate and free-stream velocity, have been confirmed both qualitatively and quantitatively. With the measurement plate oriented so that buoyancy keeps the bubbles in boundary layer, it is shown that skin friction is reduced monotonically for all air-flow rates at each of three free-stream velocities between 4 and 17 m/s. For the opposite plate orientation it is possible for increasing gas injection to lead to smaller local skin-friction reduction at the lowest speeds. Drag reduction appears to persist for as much as 60–70 boundary-layer thicknesses downstream of the injection region. It is further shown, using a probe flush-mounted just upstream of the injection section, that there is no apparent upstream interference due to the gas injection. Spectral measurements indicate that microbubbles can cause a reduction of high-frequency shear-stress fluctuations. This suggests a destruction of some of the turbulence in the near-wall region.
Automated microfluidic compact disc (CD) cultivation system of Caenorhabditis elegans

Microfabricated platforms for automated cultivation and behavioral observation of animals would be a valuable tool in physiological and genetic studies. We report an automated microfluidic compact disc (CD) system specialized for cultivating and monitoring Caenorhabditis elegans, proficient in automated feeding, waste removal and live-animal microscopy. The automated CD cultivation platform contains cultivation, nutrient, and waste chamber, channels connecting the chambers, and venting holes. The feeding and waste removal processes are achieved automatically using centrifugal force driven fluidics. Compared to other microfluidic technologies for moving small amounts of fluidic or suspended particles from site to site, this centrifuge-based system is well suited for functions such as flow sequencing, mixing, capillary measuring, and switching. Those functions can be implemented by exploiting centrifugal, coriolis and capillary forces combined with specific microfluidic network. Thus, the CD cultivating system has the capacity to incorporate diverse molecular, biochemical, and pharmacological assays for real-time physiological and behavioral tests of live-animals. This compact and fully automated microfabricated platform is designed to address the unique requirements of space biology due to the stringent limitations on power, size, weight, and crew intervention.
Current techniques used for the radiologic assessment of intracranial neoplasms.

Abstract Context.—Radiologic studies are obtained for diagnostic and treatment planning purposes in the evaluation of patients with intracranial neoplasms. These studies are discussed at radiology/pathology working conferences and are often beneficial in the analysis of pathologic specimens for tissue diagnosis. Therefore, clinical pathologists should be aware of the current and evolving imaging techniques that are used in the radiologic assessment of intracranial neoplasms. Objective.—To describe the imaging techniques used in the assessment of intracranial neoplasms and provide current references. Data Sources.—We searched PubMed for articles published between 1995 and 2006 and also reviewed several textbooks on intracranial neoplasms, to prepare a discussion of basic modalities such as computed tomography (CT) and magnetic resonance (MR) imaging as well as advanced imaging techniques such as CT and MR angiography and venography, CT and MR perfusion, MR spectroscopy, functional MR imaging, and positron ...
Breeding for Egg Quality 3. Genetic Differences in Shell Characteristics and Other Egg Quality Factors

Abstract INTRODUCTION AND LITERATURE REVIEW WHETHER efforts expended to improve egg quality traits in a breeding flock are entirely justified, is largely dependent on the hereditary nature of the egg quality factors and the amount the consumer is willing to pay for a higher quality egg. If heritability is high, improvement through selective breeding is relatively easy. If the heritability is low, improvement through breeding would be difficult and costly. With regard to the consumers there can be little doubt that they will exercise discrimination when confronted with undesirable things like meat spots, blood spots and bloody albumen. Baker and Goldman (1951) concluded from their survey in Iowa that interviewees had a much better knowledge of poor eggs than of good eggs as measured by U. S. Standards. This makes it especially difficult to estimate accurately just how much the consumer may be willing to pay for additional or unusually high …
Thin-film multielectrode arrays for potential gradient measurements in the heart

Cardiac needle (plunge) electrode arrays are constructed utilizing integrated-circuit fabrication techniques. These plunge electrodes can be made up to two orders of magnitude smaller in cross-sectional area compared to conventional handmade electrodes. A method has been developed to measure potential gradients from arrays of electrodes formed by bonding T-shaped probes back-to-back. The recording sites are situated on the vertical part of the T, and the larger bonding pads and connector wires are on the horizontal part. When inserted for recording, the horizontal portion of the probe is pulsed flush to the epicardial surface. Three sets of bipolar pairs are arranged along each vertical shift. The bipolar pairs are spaced 2.5 mm apart with a 1-mm intercontact spacing. by recording signals with both the array's initial placement and after a 90 degrees rotation of the back-to-back T arrangement, potential measurements are acquired in three mutually orthogonal directions yielding a three-dimensional configuration. Based on the differences in these potential measurements, more accurate potential gradient calculations can be obtained. >
Measuring and modeling computer virus prevalence

To understand the current extent of the computer virus problem and predict its future course, the authors have conducted a statistical analysis of computer virus incidents in a large, stable sample population of PCs and developed new epidemiological models of computer virus spread. Only a small fraction of all known viruses have appeared in real incidents, partly because many viruses are below the theoretical epidemic threshold. The observed sub-exponential rate of viral spread can be explained by models of localized software exchange. A surprisingly small fraction of machines in well-protected business environments are infected. This may be explained by a model in which, once a machine is found to be infected, neighboring machines are checked for viruses. This kill signal idea could be implemented in networks to greatly reduce the threat of viral spread. A similar principle has been incorporated into a cost-effective anti-virus policy for organizations which works quite well in practice. >
Determination of the Chromosomal Location of a Glutamate Oxaloacetate Transaminase Structural Gene Using Triticum-Agropyron Translocations

ABSTRACT The glutamate oxaloacetate transaminase (GOT) zymogram phenotypes of a series of 15 translocation lines, a chromosome addition line and a chromosome substitution line were determined. In each of the translocation lines a segment of the long arm of Triticum aestivum chromosome 3D has been replaced by a portion of an Agropyron elongatum homoeologue. Evidence was obtained that the products of the T. aestivum GOT-3 triplicate structural gene set randomly dimerize with the product of the homoeologous A. elongatum gene. Each translocation chromosome was found to carry either Got-D3 or Got-Ag3 . By correlating the zymogram phenotype expressed by each translocation line with the observed frequency of meiotic pairing of each 3D/3Ag translocation chromosome with telocentric-3DL, it was shown that Got-D3 is located in the proximal portion of 3DL, slightly more than 4.3 crossover units from the centromere. The results of this genetic study confirm and extend earlier conclusions derived from cytogenetic studies as to the physical nature of the various 3D/3Ag chromosomes.
Effects of Attention on Visuomotor Activity in the Premotor and Prefrontal Cortex of a Primate

We examined neuronal activity in the primate premotor (PM) and prefrontal (PF) areas during a demanding spatial matching task. On each behavioral trial, a rhesus monkey moved its forelimb when a visual stimulus, called the "prime stimulus," reappeared at a previously cued location. Because it triggered a movement, the part of space cued by the prime stimulus had to be either remembered or attended during the time between prime stimulus presentations. Between the first and second appearances of the prime stimulus, behaviorally irrelevant visual stimuli could appear at one or several locations other than that of the prime stimulus. We could thereby examine the activity that followed a stimulus when it was attended versus when it was irrelevant and presumably unattended. We found that visuospatial attention affected neuronal activity in both the motor and "nonmotor" parts of the frontal cortex. The magnitude of attention effects exceeded that previously reported--a finding that probably resulted from the intensive attentional demands of the present task.