cssi/SciSciGPT-SciSciNet huggingface dataset:
Gonadotropin-releasing hormone-1 (GnRH-1) is involved in tooth maturation and biomineralization.

Gonadotropin releasing-hormone-1 (GnRH-1) is expressed in mouse incisors during development. In this report, we identify (1) cell type(s) that express GnRH-1 throughout tooth development, (2) the GnRH-1 receptor, and (3) the role of GnRH-1/GnRH-1 receptor signaling in tooth maturation. Results show that GnRH-1-positive cells in dental epithelium differentiate and populate multiple tooth structures including ameloblast and papillary layers that are involved in enamel formation and mineralization. The GnRH-1 receptor was present, and in vitro a GnRH-1 antagonist attenuated incisor GnRH-1 cell expression. In vivo, in mice lacking GnRH-1 (−/−), the incisors were discolored, longer, and more curved compared to wildtype. Elemental analysis of calcium, phosphorus, and iron revealed changes in −/− incisors consistent with GnRH-1 affecting movement of minerals into the dental matrix. In sum, in tooth development a signal transduction pathway exists for GnRH-1 via the GnRH-1 receptor and disruption of such signaling affects incisor growth and biomineralization. Developmental Dynamics 236:2980–2992, 2007. Published 2007 Wiley-Liss, Inc.
STRUCTURE AND DEVELOPMENT OF VIRUSES OBSERVED IN THE ELECTRON MICROSCOPE : IV. VIRUSES OF THE RI-APC GROUP

Representative viruses of the RI-APC group were observed with the electron microscope in thin sections of infected HeLa cells. The viral particles varied in density, were approximately 60 mmicro in diameter and had a center to center spacing when close packed of about 65 mmicro. Many of the less dense particles exhibited an internal body averaging 24 mmicro in diameter. It was suggested that within the nucleus the virus differentiated from dense granular and reticular material and formed crystals. Disintegration of the crystals and disruption of the nuclear membrane with release of virus into the cytoplasm appeared to occur at any stage. No evidence to suggest development of the virus in the cytoplasm was obtained. It was possible to deduce the structure of the viral crystal from the electron micrographs. The viral particles are packed in a cubic body-centered lattice. Correlative histochemical observations in the light microscope which are now in progress revealed that the crystals and non-crystalline aggregates of virus were strongly Feulgen-positive.
A ChemoSensory questionnaire for patients treated for cancer of the head and neck.

Objectives: To investigate primary chemosensory issues experienced by patients who undergo treatment for cancer of the head and neck and to develop and assess a ChemoSensory Questionnaire (CSQ). Design: Cross sectional survey for questionnaire development and testing. Methods: Literature, expert opinion, and focus group methodology were used to identify aspects of smell and taste affecting patients before, during, and after therapy for cancer of the head and neck. A draft instrument was compiled, reviewed, and revised. The revised instrument was administered along with a demographic and clinical form, the SF-12, the Performance Status Survey, and the University of Michigan Head and Neck Quality of Life Questionnaire (HRQOL) to a sample of patients. After item and scale analyses and reductions, a final instrument was assembled. Construct validity and test-retest reliability were assessed. Results: Two hundred six patients were included in the study. The final survey instrument consisted of eight items, four on smell and four on taste. Cronbach's alpha was 0.89 for the smell scale and 0.78 for the taste scale. Correlations with other HRQOL scales ranged from 0.20 to 0.64 for the taste scale and from 0.10 to 0.33 for the smell scale. Good construct validity of the CSQ scores was demonstrated. Conclusions: Treatment for head and neck cancer negatively impacts smell and taste. A survey instrument was developed to evaluate chemosensory function that is simple to administer and is brief. This instrument will be of value in identifying factors that contribute to chemosensory disturbance and may serve as a guide for planning treatment regimens that minimize such disturbance.
Proportional reasoning and the linguistic abilities required for hypothetico‐deductive reasoning

The hypothesis is advanced that a necessary, though not sufficient, condition for the acquisition of proportional reasoning during adolescence is the prior internalization of key linguistic elements of argumentation, essentially those used in hypothetico-deductive reasoning. This hypothesized internalization, which does not occur in all individuals, results in some who have acquired the ability to reflect upon the correctness of self-generated answers in a hypothetico-deductive manner, and others who have not. As an initial test of the hypothesis, 46 subjects (Ss) (mean age = 21.03 years) were classified into additive, transitional, or proportional reasoning categories based upon responses to a proportions task. Group differences were found in which proportional Ss performed better than transitional Ss who in turn performed better than additive Ss on a number of items testing Ss' abilities to identify, generate, and use the linguistic elements of argumentation. Further it was found that some Ss who were successful on the linguistic items failed the proportions task, but no Ss who were successful on the proportions task failed the linguistic items. This result supports the hypothesis that the internalization of linguistic elements of argumentation is a prerequisite for proportional reasoning and by inference other advanced reasoning schemata as well. Implications for science instruction are drawn.
Reprogramming the male gamete genome: a window to successful gene therapy.

Abstract Hematopoiesis and spermatogenesis both initiate from a stem cell capable of renewal and differentiation. Each pathway reflects the expression of unique combinations of facultative, i.e. tissue-specific and constitutive, i.e. housekeeping, genes in each cell type. In spermatogenesis, as in hematopoiesis, commitment is mediated by the mechanism of potentiation whereby specific chromatin domains are selectively opened along each chromosome. Within each open chromatin domain, a unique battery of gene(s) is availed to tissue-specific and ubiquitous transacting factors that are necessary to initiate transcription. In the absence of an open domain, trans-factor access is denied, and the initiation of transcription cannot proceed. Cell-fate is thus ultimately defined by the unique series of open-potentiated cell-specific chromatin domains. Defining the mechanism that opens chromatin domains is fundamental in understanding how differentiation from stem cells is controlled and whether cell-fate can be modified. A recent examination of the mammalian spermatogenic pathway [Kramer, J.A., McCarrey, J.M, Djakiew, D., Krawetz, S.A., 1998. Differentiation: the selective potentiation of chromatin domains. Development 125, 4749–4755] supports the view that cell fate is mediated by global changes in chromatin conformation. This stride underscores the possibility of moderating differentiation through chromatin conformation. It is likely that gene therapeutics capable of selectively potentiating individual genic domains in populations of differentiating and/or replicating cells that modify cellular phenotype will be developed in the next millennium.
Influence of metabolic conditions on light-induced absorbancy changes in chromatium D

Abstract 1. 1. Light-induced absorbancy changes attributable to cytochromes have been studied in Chromatium D cells whose physiological state has been defined in terms of viability and capacity to take up CO 2 and O 2 . 2. 2. In fresh cells, the changes correspond closely to those described by Olson and Chance . 3. 3. After starvation to reduce intracellular electron donors, only the 422 (highest intensity light-requiring) component ★★★ remains in the reduced state in the dark; addition of reducing substrates restores the pattern of dark-light and light-dark transitions to those seen in fresh cells. 4. 4. The influence of a number of inhibitors on the spectral changes in fresh and starved cells has been studied. Mercurials and antimycin A decrease the rate at which cytochromes are reduced after period of illumination, while uncoupling reagents and phenazine methosulfate increase the rate of dark reduction. o -Phenanthroline inhibits preferentially light-induced oxidation of the 422 and 423.5 components. 5. 5. By a variety of techniques the absorption spectra of three pigments oxidised in light have been obtained. 6. 6. The experimental findings show that the 422 and 426 components are able to react directly with activated bacteriochlorophyll; the 423.5 component may react directly, but the possibility of reaction via the 422 component has not been eliminated.
Molecular cloning and characterization of NFBP6, a putative floral homeotic gene, from tobacco

NFBP6 cloned from tobacco is most closely related to petunia FBP6, a putative C-function gene. Also, NFBP6 is expressed specifically in stamens and carpels. Thus, NFBP6 provides a useful tool for molecular characterization of flower development.
A high response MoS 2 -graphene hetero-junction photodetector with broad spectral range

In this paper, we demonstrate a novel MoS2-graphene hetero junction photodetector spanning a wide spectral response from visible to infrared with a photoconduction responsivity of 24.2 mA/W at 520 nm and 2.1 mA/W at 1.01 μm.
In Arms We Trust: the Economic and Strategic Factors Motivating China-Iran Relations

This article examines contemporary China-Iran relations, focusing on the economic and strategic ties that have helped solidify the relationship since 1979. We begin with an overview of the arms and technology transfers that mark the early years of the relationship, analyzing the benefits each side gained from these transactions. In addition to discussing the short-term financial benefits behind forging stronger ties, we examine how the regional ascent of both states has also presented several long term factors that helped motivate their cooperation. These developments shed light on the important role the U.S. has played, both in terms of where it has tried to intervene and what success it has had influencing the Sino-Iranian relationship.
Suppression of hepatic prostaglandin F2α in rats by dietary α-tocopherol acetate is independent of total hepatic α-tocopherol

Abstract Groups of eight weanling female F344/N rats were fed semipurified diets that supplied 0, 50, 500, 5000, or 15 000 mg α-tocopherol acetate/kg diet, with and without 0.05% phenobarbital (PB) for 9 weeks. Both plasma and hepatic α-tocopherol levels, measured by HPLC, strongly correlated with α-tocopherol intake (r>0.73, p 2α status, as determined by radioimmunoassay. PGF 2α was significantly greater (by 52%) in rats fed no α-tocopherol than in rats fed 15 000 mg α-tocopherol acetate/kg diet. Hepatic PGF 2α status was correlated inversely but weakly with dietary α-tocopherol (r = −0.24, p 2α status was not correlated with hepatic or plasma α-tocopherol status. This finding suggests either that there is a small depletion-resistant subcellular α-tocopherol pool which regulates PGF 2α production or that α-tocopherol alters PGF 2α production in vivo by an indirect mechanism.
Human factors in industrial systems: 40 years on.

OBJECTIVE: I evaluate the contribution of a pioneering Human Factors special issue on human factors in industrial systems. BACKGROUND: Papers on the content of the journal's first 10 years showed that industrial human factors/ergonomics (HF/E) in 1969 was quite a rarity in the journal and the society. METHOD: The 12 papers in the special issue are reviewed briefly and show a wide range of topics, including traditional industrial engineering, physical HF/E, and more mainstream applications of HF/E in this domain similar to those in military and aerospace domains. The evaluation is through citations, later journal content, society technical group membership, and specific influences of Harris's own paper in the issue. RESULTS: The expected direct citation influence of this special issue was not found: Citation counts were in line with all papers in Human Factors. However, other journals have been founded in North America that serve industrial HF/E and provide an outlet for more papers per year than Human Factors. In addition, the industrial domain is well represented in the Human Factors and Ergonomics Society. Finally, Harris's paper has been influential in the specific area of HF/E in inspection. CONCLUSIONS: Industrial HF/E is now more accepted within the HF/E community, although largely in the physical ergonomics subspecialty. APPLICATION: There is now evidence of use of HF/E techniques more broadly in industry, including service as well manufacturing enterprises. Language: en
The mosquito genome – a turning point?

Of the insects that serve as vectors for parasitic diseases, the genus Anopheles is the most important. Of the approximately 400 species, about twelve serve as vectors for human pathogens. Months have passed since the sequenced genomes of the malaria parasite, Plasmodium falciparum, and its vector, Anopheles gambiae, were published. Sequences were compared, gene and protein predictions were made, new research areas evolved and many ongoing projects gained new momentum. A general belief is that we are at a turning point: we are now in a position to tackle both the parasite and the vector from new angles and with new force, for example, by identifying new drug targets and obtaining a deeper insight into molecular mechanisms of the insect, the parasite and the interactions between them.
Medieval Muddles and Modern Models: A Reply to Stuard

Stuard's critique (AA 86:410-413, 1984) of my 1979 article (Dickemann 1979a) is a massive misreading, offering no new data or analyses bearing on my hypothesis. Her title notwithstanding, she attacks not only medieval matters but my whole European section, from the Carolingian through the Renaissance. Most readers, except those with particular relish for close rebuttal, will find the original 47 pages more entertaining than what must, of necessity, follow.
Comparative lipid biochemistry— III. Plasmalogens of cardiac muscle

Abstract 1. 1. Choline plasmalogen occurred in relatively low concentration in the ventricular muscle of a number of submammalian vertebrates and in embryonic specimens of man, cat, dog and chicken. 2. 2. Mitochondria isolated from cardiac muscle had the same phosphatide pattern as the parent tissue. 3. 3. Lyso-choline plasmalogen was regularly observed in post-natal human heart and absent or in very low concentration in all other specimens examined. 4. 4. Some possible post-mortem artifacts observed in the embryonic human specimens are briefly described.
A software requirements determinations strategy utilizing provisional solutions

Research is underway to develop an effective requirements determination strategy for cases of high uncertainty or complexity. The approach involves users reviewing selected scenarios or threads of hypothetical system behavior during the early stages of system conceptualization. The scenarios are generated from the specifications of provisional system solutions and represent sequences of events corresponding to specific uses of generic system capabilities. The strategy requires that system specifications be developed with requirements elicitation in parallel and includes sufficient operational information for the construction of useful scenarios. Software testing strategies have been adapted to aid in designing scenarios which adequately cover a system's behavior. A prototype requirements exploration environment is being developed which provides support for requirements, scenarios, and capturing the requirements history.
Temperature Dependent Thermal Properties in LEDs for Solid State Lighting

Over 20% of electricity in US is used by lighting. Solid state lighting (SSL) efficiency can surpass that of incandescent and fluorescent lighting techniques. Nonetheless SSL efficiency is greatly reduced at high temperatures that result from inadequate heat dissipation. SSL requires blue and green light emitting diodes (LEDs) made from Gallium Nitride (GaN) and Indium Gallium Nitride (InGaN) to eventually generate white light. Conduction within the LED is a major thermal resistance for heat dissipation, and motivates study of thermal properties of LED materials, including GaN and InGaN. Bulk thermal properties are poor estimates of thin film properties due to increased boundary and defect scattering of phonons in the films. By examining real nitride based LED architectures with the 3-omega technique, thin film thermal conductivities of nucleation, buffer, contact, and active regions were measured from 100–400K. We find that the AlN nucleation layer is a bottleneck to heat transfer, having a thermal conductivity (κ) two orders of magnitude less than bulk crystalline AlN. Further, the temperature dependent behavior is characteristic of an amorphous solid. TEM images of the AlN layer show a very high dislocation density (4×1010 cm−2). We hypothesize that scattering from these dislocations as well as the film boundaries, causes the observed behavior.Copyright © 2012 by ASME
Emergency workers' cognitive appraisal and coping with traumatic events

Police, fire, emergency medical and hospital personnel were surveyed following two disasters in the same county: An apartment building explosion followed 1 year later by a devastating tornado. They completed a symptom checklist, the Coping Inventory, and rated the extent of their support networks. Reported symptoms revealed clinically significant emotional effects postdisaster. More post-traumatic symptoms were reported following the tornado. Coping theory emphasizing cognitive appraisal was used as the conceptual framework for studying reported adjustment strategies. Workers' comments illustrated the cognitive processes intervening between the emergency events and reactions to them. The most frequently endorsed coping strategies following both events involved attempts to reach cognitive mastery over the event and to ascertain meaning. Strategies of altering activities and finding new interests were not frequently endorsed. A greater number of coping responses were endorsed following the tornado along with strategies which involved seeking support from others. Factor analysis of Coping Inventory responses revealed four factors: seeking of meaning, regaining mastery through individual action, regaining mastery through interpersonal action, and philosophical self-contemplation.
Optical time-domain mixer

We simulate an optical time-domain mixer that can be used to make a photonic analog-to-digital converter (ADC) or a digital demodulator for high-speed optical communications signals. In the basic mixer, a high frequency RF signal modulates a repetitively chirped optical carrier; this RF/optical waveform then is dispersed in one transverse dimension, and imaged onto a 2-dimensional transparency or spatial light modulator whose pixels are modulated with randomly chosen transmission or reflection coefficients (the optical mixing matrix). Following transmission through or reflection from the mixing matrix, the optical waveform from each row of the matrix is recombined and directed to a photodiode and electronics that integrate over the repetition period of the chirped source. Finally, each of these signals is digitized by an independent ADC sampling at a rate equal to the pulse repetition rate of the chirp source. A digital replica of the input RF signal can be recovered by digital signal processing from the digital output of the ADCs and the values of the transmission or reflection coefficients of the mixing matrix. The effective sampling rate is given by the number of pixels per row of the mixing matrix times the repetition rate of the chirp source while the effective resolution is controlled by the resolution of the electronic ADCs and the distortions introduced by the optical mixing process.
Optical response of magnetic fluorescent microspheres used for force spectroscopy in the evanescent field.

Force spectroscopy based on magnetic tweezers is a powerful technique to manipulate single biomolecules and study their interactions. The resolution in a magnetic probe displacement, however, needs to be commensurate with molecular sizes. To achieve the desirable sensitivity in tracking displacements of the magnetic probe, some recent approaches have combined magnetic tweezers with total internal reflection fluorescence microscopy. In this situation, a typical force probe is a polymer microsphere containing two types of optically active components – a pure absorber (magnetic nanoparticles for providing the pulling force) and a luminophore (semiconducting nanoparticles or organic dyes for fluorescent imaging). In order to fully assess the system’s capability for tracking the position of the force probe with sub-nanometer accuracy, we developed a body-of-revolution formulation of the method of auxiliary sources (BOR-MAS) to simulate absorption, scattering, and fluorescence of microscopic spheres in an evanescent electromagnetic field. The theoretical formulation uses the axial symmetry of the system to reduce the dimensionality of the modeling problem and produces excellent agreement with the reported experimental data on forward scattering intensity. Using the BOR-MAS numerical model, we investigated the probe detection sensitivity for a high numerical aperture objective. The analysis of both backscattering and fluorescence observation modes shows that the total intensity of the bead image decays exponentially with the distance from the surface (or the length of a biomolecule). Our investigations demonstrate that the decay lengths of observable optical power are smaller than the penetration depth of the unperturbed excitation evanescent wave. In addition, our numerical modeling results illustrate that the expected sensitivity for the decay length changes with the incident angle, tracking the theoretical penetration depth for a two-media model, and is sensitive to the bead size. The BOR-MAS methodology developed in this work for near field modeling of bead tracking experiments fully describes the fundamental photonic response of microscopic BOR probes at the sub-wavelength level and can be used for future improvements in the design of these probes or in the setup of bead tracking experiments.
Problem-solving behavior in a system model of the primate neocortex

Abstract We show how our previously described system model of the primate neocortex can be extended to allow the modeling of problem-solving behaviors. Specifically, we model different cognitive strategies that have been observed for human subjects solving the Tower of Hanoi problem. These strategies can be given a naturally distributed form on the primate neocortex. Further, the goal stacking used in some strategies can be achieved using an episodic memory module corresponding to the hippocampus. We can give explicit falsifiable predictions for the time sequence of activations of different brain areas for each strategy.
Metastatic lung cancer presenting as embolic renal infarction: Use of ultrasound in diagnosing acute renal artery occlusion

Sequelae of cardiac metastases rarely account for the initial clinical presentation of patients with malignancy. A patient presented with right renal embolic infarction diagnosed with Doppler ultrasonography. Further studies revealed bronchogenic carcinoma and a left atrial metastasis from which the embolus had originated. This case illustrates the value of supplementing gray-scale ultrasonography with Doppler in selected cases of acute renal and urinary tract disease.
The effects of hydrocarbons on the setting of the American oyster, Crassostrea virginica , in intertidal habitats in Southeastern North Carolina

Effects of petroleum covered substrate on intertidal oyster spat (Crassostrea virginica) set were measured at three intertidal elevations in a southeastern North Carolina estuary.Mercenaria mercenaria shells were coated with Bunker C crude oil or a 40∶1 mixture of gasoline: 2-cycle engine oil and placed intertidally for seven 13-d periods. Spat densities were significantly lower on oil treatments versus control and gas-treated shells in the high intertidal zone. This was principally attributed to an increased sediment coat on oiled shells. Maximum spat size was smaller on oil-treated shells at all elevations when compared to gas and control shells, indicating that setting may be delayed on oiled shell. For all experimental 13-d periods in the low intertidal zone and for three periods in the mid-tidal zone, barnacle densities (primarilyBalanus improvisus andB. eburneus) were significantly greater on oiled shells than on control shells.
The TFIIB Tip Domain Couples Transcription Initiation to Events Involved in RNA Processing

TFIIB is the only factor within the multimegadalton transcription complex that is obligatorily required to undergo dissociation and re-association with each round of mRNA transcription. Here we show that a six-amino acid human TFIIB tip region is needed for appropriate levels of serine 5 C-terminal domain phosphorylation and mRNA capping and for retention of the required elongation factor TFIIF. We suggest that the broad functions of this tiny region are used to suppress transcription noise by restricting functional RNA synthesis from non-promoter sites on the genome, which will not contain TFIIB.
The effect of substrate temperature and source flux on cubic ZnMgO UV sensors grown by plasma-enhanced molecular beam epitaxy

Abstract Cubic ZnMgO films were grown by plasma-enhanced molecular beam epitaxy on MgO substrates. Interdigitatal metal–semiconductor–metal contacts were fabricated with Ni/Mg/Au to investigate the effect of growth temperature and source flux ratio on UV sensor properties. Device spectral responsivity was found to decrease with increasing Mg content, while UV–visible rejection ratio correspondingly increased. Peak responsivities ranged from 236 nm to 260 nm, spanning from 10 mA/W in the single crystal, high Mg case to ∼500 A/W for phase segregated films. UV–visible rejection ratios increased with increasing Mg content to three orders of magnitude. Solar blind detectors were realized with single-crystal ZnMgO, while effective visible blind detectors were made with phase-segregated ZnMgO films.
Spectroscopic and electrochemical studies of oriented monolayers on electrode surfaces

Abstract A series of electrochemical and Raman studies were undertaken to investigate the effects of orientation of electroactive species on their electrochemical behavior. Raman, resonance Raman, surface-enhanced Raman scattering, and surface-enhanced resonance Raman scattering techniques provided information essential for determining species orientation on electrode surfaces. The paradigm compounds employed were a series of derivatized viologens. Synthesis of these compounds involved the incorporation of long alkyl chains, rendering them surface-active and capable of incorporation into various kinds of oriented systems at interfaces. Orientation control was effected by the use of three techniques which provided a hierarchy of progressively more stringently oriented systems. Viologens were incorporated into vesicles, spontaneously self-assembled systems, and Langmuir-Blodgett (LB) monolayer arrays. Whereas the ordering and orientation control was probably least effective in vesicles, a maximal ordering could be attained in LB systems. Analysis of the experimental findings indicates that the systems studied show varied behavior and a complex interaction of the important variables operative during electrochemical processes. The extent of orientation present in specific preparations, the electrochemical potentials, the presence of counterions, the density of monolayer packing, and the exact structures (relative contributions of alkyl chains and of the viologen moiety) were all found to influence the behavior observed.
Bells, electronic carillons, and chimes

Bells and chimes, unlike the more familiar string and wind instruments, produce tones in which the overtone structure cannot be expressed as a series of harmonics. The accuracy of tuning of the various overtones varies widely but the better cast bell carillons, electronic carillons, and tubular chimes do have very accurately tuned overtones. This paper describes the results of measurements on cast bells, electronic carillons, and tubular chimes. Data will be given on relative amplitude and decay rates of the various overtones. The reaction of "out-of-tuneness" will be discussed and explained. A new type of tone source for electronic carillons will be described. With this new tone source, a rod of carefully controlled rectangular cross section is used. This rod can give in a single unified structure essentially the same overtone array as that of an accurately tuned cast carillon bell.
Diphenylhydantoin-Induced hypogammaglobulinemia in a patient infected with Human immunodeficiency virus

A case is reported of reversible panhypogammaglobulinemia in a human immunodeficiency virus (HIV)-infected patient. Onset and resolution were temporally correlated with initiation and termination, respectively, of diphenylhydantoin therapy for a possible seizure. A rapid alteration in peripheral T-cell subpopulations was also noted in association with diphenylhydantoin administration. This case is compared with previous reports of diphenylhydantoin-associated hypogammaglobulinemia in non-HIV-infected patients. In addition, the case is discussed with regard to possible deleterious effects associated with the use of diphenylhydantoin as therapy for HIV-associated seizures or as an antiretroviral agent in HIV disease.
Contaminants of Emerging Concern in Fish from Western U.S. and Alaskan National Parks — Spatial Distribution and Health Thresholds

Remote national parks of the western U.S. and Alaska are not immune to contaminants of emerging concern. Semivolatile organic compounds (SOCs) such as pesticides and PCBs can selectively deposit from the atmosphere at higher rates in cold, high-elevation and high-latitude sites, potentially increasing risk to these ecosystems. In the environment, SOCs magnify up food chains and are known to increase health risks such as cancer and reproductive impairment. One hundred twenty-eight fish in 8 national parks in Alaska and the western U.S. were analyzed for contaminant concentrations, assessed by region, and compared to human and wildlife health thresholds. SOC concentrations from an additional 133 fish from a previous study were also included, for a total of 31 water bodies sampled. PCBs, endosulfan sulfate, and p,p′-DDE were among the most frequently detected contaminants. Concentrations of historic-use pesticides dieldrin, p,p′-DDE, and/or chlordanes in fish exceeded USEPA guidelines for human subsistence fish consumers and wildlife (kingfisher) health thresholds at 13 of 14 parks. Average concentrations in fish ranged from 0.6-280 ng/g lipid (0.02-7.3 μg/g ww). Contaminant loading was highest in fish from Alaskan and Sierra Nevada parks. Historic compounds were highest in Alaskan parks, while current-use pesticides were higher in the Rockies and Sierra Nevada. This study provides a rigorous analysis of CECs in fish from national parks and identifies regions at potential risk.
Representation of protein 3D structures in spherical (ρ, ϕ, θ) coordinates and two of its potential applications

Three-dimensional objects can be represented using cartesian, spherical or cylindrical coordinate systems, among many others. Currently all protein 3D structures in the PDB are in cartesian coordinates. We wanted to explore the possibility that protein 3D structures, especially the globular type (spheroproteins), when represented in spherical coordinates might find useful novel applications. A Fortran program was written to transform protein 3D structure files in cartesian coordinates (x,y,z) to spherical coordinates (ρ, ϕ, θ), with the centroid of the protein molecule as origin. We present here two applications, namely, (1) separation of the protein outer layer (OL) from the inner core (IC); and (2) identifying protrusions and invaginations on the protein surface. In the first application, ϕ and θ were partitioned into suitable intervals and the point with maximum ρ in each such 'ϕ-θ bin' was determined. A suitable cutoff value for ρ is adopted, and for each ϕ-θ bin, all points with ρ values less than the cutoff are considered part of the IC, and those with ρ values equal to or greater than the cutoff are considered part of the OL. We show that this separation procedure is successful as it gives rise to an OL that is significantly more enriched in hydrophilic amino acid residues, and an IC that is significantly more enriched in hydrophobic amino acid residues, as expected. In the second application, the point with maximum ρ in each ϕ-θ bin are sequestered and their frequency distribution constructed (i.e., maximum ρ's sorted from lowest to highest, collected into 1.50A-intervals, and the frequency in each interval plotted). We show in such plots that invaginations on the protein surface give rise to subpeaks or shoulders on the lagging side of the main peak, while protrusions give rise to similar subpeaks or shoulders, but on the leading side of the main peak. We used the dataset of Laskowski et al. (1996) to demonstrate both applications.
Impact of source collinearity in simulated PM2.5 data on the PMF receptor model solution

Abstract Positive Matrix Factorization (PMF) is a factor analytic model used to identify particle sources and to estimate their contributions to PM 2.5 concentrations observed at receptor sites. Collinearity in source contributions due to meteorological conditions introduces uncertainty in the PMF solution. We simulated datasets of speciated PM 2.5 concentrations associated with three ambient particle sources: “Motor Vehicle” (MV), “Sodium Chloride” (NaCl), and “Sulfur” (S), and we varied the correlation structure between their mass contributions to simulate collinearity. We analyzed the datasets in PMF using the ME-2 multilinear engine. The Pearson correlation coefficients between the simulated and PMF-predicted source contributions and profiles are denoted by “ G correlation” and “ F correlation”, respectively. In sensitivity analyses, we examined how the means or variances of the source contributions affected the stability of the PMF solution with collinearity. The % errors in predicting the average source contributions were 23, 80 and 23% for MV, NaCl, and S, respectively. On average, the NaCl contribution was overestimated, while MV and S contributions were underestimated. The ability of PMF to predict the contributions and profiles of the three sources deteriorated significantly as collinearity in their contributions increased. When the mean of NaCl or variance of NaCl and MV source contributions was increased, the deterioration in G correlation with increasing collinearity became less significant, and the ability of PMF to predict the NaCl and MV loading profiles improved. When the three factor profiles were simulated to share more elements, the decrease in G and F correlations became non-significant. Our findings agree with previous simulation studies reporting that correlated sources are predicted with higher error and bias. Consequently, the power to detect significant concentration-response estimates in health effect analyses weakens.
EFFECT OF LIGHT ON VERTICAL MIGRATION AND PHOTOSYNTHESIS OF EUGLENA PROXIMA (EUGLENOPHYTA)

During daytime low tides, sediment-inhabiting populations of Euglena proxima Dangeard migrate to the surface of intertidal sand flats to form large monospecific green patches near the Duke University Marine Laboratory in Beaufort, North Carolina. The effect of incident irradiance on the upward migration of E. proxima was studied by shading the sediment surface in the field with neutral density filters to 2, 20, 55, and 100% incident irradiance. The results of these in situ experiments revealed that E. proxima’s upward migration, as measured by population density or chl a concentration, was stimulated by decreasing incident irradiance: population densities and chl a concentrations on the sediment surface at 2% incident irradiance were greater statistically than at 100% full sunlight. In situ measurements of photosynthesis were performed by incubating 3-mL aliquots of a cell suspension in scintillation vials containing 14C inorganic carbon beneath neutral density filters. These experiments revealed that E. proxima exhibited photoinhibition at 100% full sunlight, but this depression in photosynthetic performance at high light was absent when the cells were incubated in vials containing acid-cleaned sediment. This amelioration of photoinhibition in vials containing sediment is most likely due to the downward migration of the population away from photoinhibitory light levels. These results cannot be interpreted as strictly photic effects because the temperature of the vials varied with the light treatment. The results of this study suggest that the vertical migration behavior of E. proxima and its photosynthetic physiology are intimately linked. Vertical migration provides a mechanism to deal with short-term changes in irradiance and avoid photoinhibitory light levels.
Protein translocation across mitochondrial membranes: What a long, strange trip it is

Hundreds of nuclear-encoded proteins are required for mitochondrial metabolism, growth, division, and partitioning to daughter cells, and virtually all of these proteins must be imported into the organelle. Many of these imported proteins must cross two membranes to reach their destination inside mitochondria. Complicating matters, the inner membrane (IM) must maintain a electrochemical potential to drive the synthesis of ATP. Over the past 10 years, researchers have identified at least 18 different proteins that orchestrate the targeting and translocation of precursor proteins across the outer membrane (OM) and IM (reviewed by Kubrich et al., 1995). The current focus of the field is to determine the mechanism of each step in the import pathway. In this minireview we will highlight recent information about the interaction of precursors with OM receptors, the composition and function of each membrane’s translocation machinery, and the cooperation of OM and IM import machines. Mitochondrial Stimulation Factor Is a Cytosolic Chaperone That Recognizes Import Signals Cytoplasmic chaperones, such as the Hsp70 family of heat shock proteins, are thought to maintain newly synthesized proteins in a translocation-competent conformation by preventing their premature or improper folding. Many mitochondrial precursor proteins, however, need a cytosolic factor other than the Hsp70s, suggesting the existence of additional import chaperones. In a major advance, Hachiya et al. (1994) purified a remarkable cytosolic factor, the mitochondrial stimulation factor (MSF). MSF differs from other chaperones in three important ways: it specifically recognizes mitochondrial import signals, it directly targets precursors to receptors on the mitochondrial surface, and it actively disperses protein aggregates. Minireview
HIV-1 Infection Does Not Impair Human Alveolar Macrophage Phagocytic Function Unless Combined With Cigarette Smoking

Objective Macrophages are an important reservoir for the HIV and contribute to innate lung defense by their ability to phagocytose, digest, and process invading pathogens. We hypothesized that HIV-1 infection may lead to a defect in the phagocytic activity of alveolar macrophages. Design In order to test this hypothesis, the phagocytic activity of alveolar macrophages from asymptomatic HIV-1 seropositive subjects was compared to healthy seronegative control subjects. Macrophages from one cohort were fed with Escherichia coli and from another cohort with opsonized sheep RBCs (SRBCs), and the phagocytic index was determined at different time intervals. Setting A tertiary-care, urban, university-based referral center. Participants Asymptomatic HIV-1 seropositive subjects and healthy seropositive control subjects recruited from local community. Results No differences were found in the phagocytic activity between alveolar macrophages from the first cohort of eight seropositive and nine seronegative subjects. Although not statistically significant, there was a trend toward a lower phagocytic activity of HIV-positive smokers compared to HIV-positive nonsmokers. Opsonized phagocytic capacity (using opsonized SRBCs) was further analyzed in a second set of five HIV-positive subjects and five healthy control subjects. Whereas HIV status did not affect opsonized SRBC uptake, a history of smoking was associated with a statistically significant depression in phagocytic index. Conclusions Although there is no significant impairment of phagocytic capacity in HIV-positive subjects compared to HIV-negative control subjects, cigarette smoking produces a significant depression in phagocytic activity that is amplified in HIV-positive smokers.
Diagnostic reliability of the Semi-structured Assessment for Drug Dependence and Alcoholism (SSADDA)

Abstract The Semi-structured Assessment for Drug Dependence and Alcoholism (SSADDA) is a diagnostic instrument developed for studies of the genetics of substance use and associated disorders. The SSADDA provides more detailed coverage of specific drug use disorders, particularly cocaine and opioid dependence, than existing psychiatric diagnostic instruments. A computerized version of the SSADDA was developed to permit direct entry of subject responses by the interviewer. This study examines the diagnostic reliability of the SSADDA for substance use disorders and for other DSM-IV disorders that are commonly associated with substance use disorders. Methods Two hundred and ninety-three subjects (mean age = 39 yr, 52.2% women) were interviewed twice over a 2-week period in two sub-studies examining the inter-rater ( n = 173) or test–retest reliability ( n = 120) of the SSADDA. The κ statistic and Yule's Y were used to measure reliability. Results The reliability of most substance dependence diagnoses was good to excellent, although the reliability of substance abuse diagnoses was substantially lower. The reliability of the associated psychiatric diagnoses varied from fair to excellent. Conclusions The SSADDA yields reliable diagnoses for a variety of psychiatric disorders, including alcohol and drug dependence. Although developed for use in genetic studies, its broad and detailed coverage of disorders and computer-assisted format will allow it to be used in a variety of applications requiring careful diagnostic assessment.
Model for Oxide Wearout Due to Charge Trapping

Scaling of MOS gate oxides below 200A can result in wearout of intrinsic oxides. This paper presents studies of thin gate oxides which show that the time dependent nature of oxide breakdown is due to charge trapping induced by leakage current. Failure occurs when the trapped charge increases the internal electric field in the oxide to a critical value of 11.2 MV/cm needed for avalanche breakdown. By measuring trapping parameters such as trap centroids and generation/recombination rates versus stress fields, a mathematical model for time dependent oxide wearout has been developed.
Estimating snow accumulation from InSAR correlation observations

Snow accumulation in remote regions, such as Greenland and Antarctica, is a key factor for estimating the Earth's ice mass balance. In situ data are sparse; hence, they are useful to derive snow accumulation from remote sensing observations, such as microwave thermal emission and radar brightness. These data are usually interpreted using electromagnetic models in which volume scattering is the dominant mechanism. The main limitation of this approach is that microwave brightness is not well related to backscatter if the ice sheet is layered. Because larger grain size and thicker annual layers both increase radar image brightness, with the first corresponding to lower accumulation rate and the second to higher accumulation rate, models of radar brightness alone cannot accurately reflect accumulation. Consideration of correlation measurements can also resolve this ambiguity. We introduce an interferometric ice scattering model that relates the interferometric synthetic aperture radar correlation and radar brightness to both ice grain size and hoar layer spacing in the dry-snow zone of Greenland. We use this model and the European Remote Sensing satellite radar observations to derive several parameters related to snow accumulation rates in a small area in the dry-snow zone. These parameters show agreement with four in situ core accumulation rate measurements in this area, whereas models using only radar brightness data do not match the observed variation in accumulation rates
Strategic analysis for the MER Cape Verde approach

The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, uncharacterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe.
Intelligent Electronic Navigational Aids: A New Approach

Intelligent devices, with smart clutter management capabilities, can enhance a user?s situational awareness under adverse conditions. Two approaches to assist a user with target detection and clutter analysis are presented, and suggestions on how these tools could be integrated with an electronic chart system are further detailed. The first tool, which can assist a user in finding a target partially obscured by display clutter, is a multiple-view generalization of AdaBoost. The second technique determines a meaningful measure of clutter in electronic displays by clustering features in both geospatial and color space. The clutter metric correlates with preliminary, subjective, clutter ratings. The user can be warned if display clutter is a potential hazard to performance. Synthetic and real data sets are used for performance evaluation of the proposed technique compared with recent classifier fusion strategies.
Shear stress increases nitric oxide production in thick ascending limbs

We showed that luminal flow stimulates nitric oxide (NO) production in thick ascending limbs. Ion delivery, stretch, pressure, and shear stress all increase when flow is enhanced. We hypothesized t...
Oscillatory flow past a circular cylinder in a rotating frame

Because of the importance of oscillatory components in the oncoming flow at certain oceanic topographic features, we investigate the oscillatory flow past a circular cylinder in an homogeneous rotating fluid. When the oncoming flow is non-reversing, and for relatively low-frequency oscillations, the modifications to the equivalent steady flow arise principally in the ‘quarter layer’ on the surface of the cylinder. An incipient-separation criterion is found as a limitation on the magnitude of the Rossby number, as in the steady-flow case. We present exact solutions for a number of asymptotic cases, at both large frequency and small nonlinearity. We also report numerical solutions of the nonlinear quarter-layer equation for a range of parameters, obtained by a temporal integration. Near the rear stagnation point of the cylinder, we find a generalized velocity ‘plateau’ similar to that of the steady-flow problem, in which all harmonics of the free-stream oscillation may be present. Further, we determine that, for certain initial conditions, the boundary-layer flow develops a finite-time singularity in the neighbourhood of the rear stagnation point.