cssi/SciSciGPT-SciSciNet huggingface dataset:
A quantitative genetic model of altruistic selection

A quantitative genetic model for evolution by altruistic selection based on family selection models used in agricultural genetics is presented. A quantitative genetic version of Hamilton's rule is derived which indicates that evolution will proceed in an altruistic direction whenever the ratic of between-to within-family (or group) heritability exceeds the absolute value of the within-to between-family selection differential ratio. This ratio of heritabilities is equal to a ratio which includes only the phenotypic and genetic intraclass correlation coefficients, thus no heritabilities actually need to be estimated in determining the possibility of altruistic evolution. The phenotypic intraclass correlation can be estimated with standard analysis of variance methods. The genetic intraclass correlation may be estimated by the average within-group coefficient of relationship using genealogical data, by Wright's F-statistics using allele frequency data, or by a theoretical model based on a knowledge of interaction and mating patterns. Selection differentials may be measured by the regression of relative fitness, or one of its major components, on the phenotype of interest. Selection can be considered altruistic only if within-and between-family selection differentials have opposite signs. Consideration of empirical data on genetic and phenotypic intraclass correlations indicates that evolution may proceed in an altruistic direction even if the within-family selection differential exceeds the one between families, especially in situations in which pertinent environmental factors are randomly distributed among families.
Electrowetting lenses for compensating phase and curvature distortion in arrayed laser systems

We have demonstrated a one-dimensional array of individually addressable electrowetting tunable liquid lenses that compensate for more than one wave of phase distortion across a wavefront. We report a scheme for piston control using tunable liquid lens arrays in volume-bound cavities that alter the optical path length without affecting the wavefront curvature. Liquid lens arrays with separately tunable focus or phase control hold promise for laser communication systems and adaptive optics.
Effects of Nitrogen on the Selective Dissolution of a Duplex Stainless Steel

Abstract Nitrogen (N) has been shown to exert a beneficial influence on localized corrosion resistance of austenitic stainless steels. With duplex stainless steels (SSs), N plays a dual role of controlling the austenite to ferrite ratio and increasing corrosion resistance. In addition, on rapid cooling from high temperatures, N can form deleterious precipitates in the ferrite reducing corrosion resistance. The corrosion resistance and corrosion modes are quite different in N and non-N duplex SSs. These differences are illustrated for a 25%Cr duplex SS.
Improving navigation and learning in hypertext environments with navigable concept maps

This article discusses the design of Concept Mapped Project-Based Activity Scaffolding System (CoMPASS) and the theoretical foundations that it is based on. CoMPASS is a hypertext system that presents students with external, graphical representations in the form of concept maps as well as textual representations both of which change dynamically as students traverse through the domain and make navigational decisions. In a study in which middle school students used CoMPASS, students' navigation paths, as well as their learning outcomes, were analyzed. A comparison class in which students used the system without the maps for navigation provided information about students' use of the maps for navigation and its effect on their learning. It was found that students who used the maps version of the system performed significantly better in a concept mapping test as well as an essay test, and their navigation was more focused. This article discusses the findings of the study and its implications for designing hypertext systems.
High-resolution mapping of Rsn1, a locus controlling sensitivity of rice to a necrosis-inducing phytotoxin from Rhizoctonia solani AG1-IA

Rhizoctonia solani is a necrotrophic fungal pathogen that causes disease on many crop-plant species. Anastomosis group 1-IA is the causal agent of sheath blight of rice (Oryza sativa L.), one of the most important rice diseases worldwide. R. solani AG1-IA produces a necrosis-inducing phytotoxin and rice cultivar’s sensitivity to the toxin correlates with disease susceptibility. Unlike genetic analyses of sheath blight resistance where resistance loci have been reported as quantitative trait loci, phytotoxin sensitivity is inherited as a Mendelian trait that permits high-resolution mapping of the sensitivity genes. An F2 mapping population derived from parent cultivars ‘Cypress’ (toxin sensitive) and ‘Jasmine 85’ (toxin insensitive) was used to map Rsn1, the necrosis-inducing locus. Initial mapping based on 176 F2 progeny and 69 simple sequence repeat (SSR) markers located Rsn1 on the long arm of chromosome 7, with tight linkage to SSR marker RM418. A high-resolution genetic map of the region was subsequently developed using a total of 1,043 F2 progeny, and Rsn1 was mapped to a 0.7 cM interval flanked by markers NM590 and RM418. Analysis of the corresponding 29 Kb genomic sequences from reference cultivars ‘Nipponbare’ and ‘93-11’ revealed the presence of four putative genes within the interval. Two are expressed cytokinin-O-glucosyltransferases, which fit an apoptotic pathway model of toxin activity, and are individually being investigated further as potential candidates for Rsn1.
Kinetics and Mechanism of the Dihydroxylation and Epoxidation of Conjugated Dienes with Hydrogen Peroxide Catalyzed by Methylrhenium Trioxide.

The title reactions occur readily. With acetonitrile chosen as the solvent, 17 of them were studied by kinetic methods. As is true for other MTO-catalyzed reactions, peroxorhenium complexes are the active species. Under the conditions of hydrogen peroxide present in large excess, usually employed here, CH3Re(O)(η2-O2)2(OH2) was the major reactive catalyst present. The rate constant between it and the dienes increase or decrease as substituents add or remove electron density from the CC bonds, suggesting a concerted mechanism in which the double bond attacks a peroxide oxygen. Many of the products are diols, some rearranged, except when the stability of carbocation intermediates for epoxide ring opening are so unstable as to prolong their lives. When urea−hydrogen peroxide was used instead, the monoepoxides were obtained.
Atrial natriuretic factor inhibits angiotensin-induced aldosterone secretion: Not through cGMP or interference with phospholipase C

Abstract ANF did not prevent the formation of [3H] inositol trisphosphate in response to All but inhibited aldosterone secretion in calf adrenal glomerulosa cells. 8-bromo cGMP did not affect either inositol phosphate formation or aldosterone secretion. Changes in cytosolic Ca++ concentration induced by All, as measured by Quin 2 fluorescence, were also unaffected by ANF. No difference in adrenal cell protein phosphorylation with All or All+ANF was observed. The results suggest that ANF may inhibit aldosterone secretion through a non-guanyl cyclase linked receptor system not involving the formation of phosphoinositide-derived second messengers. Interference with protein kinase C activity cannot be ruled out.
Cognitive recovery correlates with long-term increases of cerebral perfusion after head injury

Prospective measurements of cerebral blood flow (CBF) and Cognitive Capacity Screening Examination (CCSE) were obtained following head injury among 42 patients for a mean total follow-up interval of 10 years. Clinical data obtained at the time of injury and detailed neurological examinations at each follow-up visit were correlated with serial CBF and CCSE scores. Comparisons of the group of patients who cognitively improved (n = 32) were made with the group that did not (n = 10). Of the total group, 76% showed cognitive improvements for as long as 10 years after injury, with CBF increases toward normal. Predictors for long-term cognitive improvements include: higher initial Glasgow Coma Scales, earlier recovery from coma, absence of signs of brain stem injury, and improvements of cerebral perfusion and autoregulation. Failure to improve correlated with low initial Glasgow Coma Scales, signs of brain stem injury, and persistent impairments of cerebral perfusion.
Nemo-like kinase induces apoptosis and inhibits androgen receptor signaling in prostate cancer cells.

BACKGROUND The mitogen-activated protein kinases (MAPKs) regulate cell growth, differentiation, and stress responses, and many critical signaling pathways are subject to cross-regulation by MAPK signaling. Previous studies have yielded evidence of cross-talk between the MAPK pathways and androgen receptor (AR) signaling, which plays a critical role in growth control of both normal prostate and prostate cancer (PCa). Objective of this study was to evaluate the expression of MAPK-like protein nemo-like kinase (NLK) in PCa and its effects on AR-mediated transcription. METHODS Real-time PCR and IHC were used to evaluate levels of NLK in prostatic samples. Effects of over-expression of NLK on apoptosis and proliferation were determined using Western blot and flow cytometry. Effects on AR signaling were evaluated using over-expression and knockdown of NLK in PCa cells in combination with PCR, Western blotting and reporter assays. RESULTS Our results show that the expression of NLK is decreased in PCa metastases in comparison to normal prostate epithelium and primary PCa. Our results also show that over-expression of NLK resulted in induction of apoptosis, which was more pronounced in AR-expressing LNCaP versus AR-negative PC-3 cells. Higher levels of NLK decreased levels of AR mRNA and protein as well as inhibited AR-mediated transcription. CONCLUSIONS NLK expression is altered during PCa progression and it is involved in regulation of AR signaling in these cells. A deeper understanding of the roles of NLK in regulation of AR-mediated transcription and control of PCa progression may point the way to new modes of therapeutic intervention in this disease. Prostate 69: 1481–1492, 2009. © 2009 Wiley-Liss, Inc.
End-stacking of copper cationic porphyrins on parallel-stranded guanine quadruplexes.

Nucleic acids that contain multiple sequential guanines assemble into guanine quadruplexes (G-quadruplexes). Drugs that induce or stabilize G-quadruplexes are of interest because of their potential use as therapeutics. Previously, we reported on the interaction of the Cu2+ derivative of 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21H,23H-porphine (CuTMpyP4), with the parallel-stranded G-quadruplexes formed by d(T4G n T4) (n = 4 or 8) (Keating and Szalai in Biochemistry 43:15891–15900, 2004). Here we present further characterization of this system using a series of guanine-rich oligonucleotides: d(T4G n T4) (n = 5–10). Absorption titrations of CuTMpyP4 with all d(T4G n G4) quadruplexes produce approximately the same bathochromicity (8.3 ± 2 nm) and hypochromicity (46.2–48.6%) of the porphyrin Soret band. Induced emission spectra of CuTMpyP4 with d(T4G n T4)4 quadruplexes indicate that the porphyrin is protected from solvent. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry revealed a maximum porphyrin to quadruplex stoichiometry of 2:1 for the shortest (n = 4) and longest (n = 10) quadruplexes. Electron paramagnetic resonance spectroscopy shows that bound CuTMpyP4 occupies magnetically noninteracting sites on the quadruplexes. Consistent with our previous model for d(T4G4T4), we propose that two CuTMpyP4 molecules are externally stacked at each end of the run of guanines in all d(T4G n T4) (n = 4–10) quadruplexes.
Antigenicity, storage, and aging: physiologic autoantibodies to cell membrane and serum proteins and the senescent cell antigen

Normal human serum contains autoantibodies to a wide range of cellular and serum proteins. IgG autoantibodies to cell membrane proteins spectrin, syndein (Band 2.1), Band 3 degradation products, and the senescent cell antigen are among them. Physiologic autoantibodies to the senescent cell antigen, a ∼62 000 dalton glycopeptide derived from Band 3, initiate removal of senescent, damaged, and stored cells in vivo. The senescent cell antigen is one of the two Band 3 degradation products (Mr ∼ 66 000 and 62 000) observed in freshly prepared ghosts. Since the senescent cell antigen is observed on red cells aged in situ, data suggest that Band 3 undergoes proteolysis in situ. IgG eluted from blood stored for transfusion binds to the senescent cell antigen. The amount of IgG on red cells increases during storage suggesting accumulation of the senescent cell antigen. Autoantibodies to other cell and serum proteins are discussed as possible regulators of homeostasis. The effect of age on physiologic autoantibodies is reviewed.
Analysis of the optogalvanic effect in discharge plasmas using rate equations in a modified Schottky formalism

A rate analysis approach is used to evaluate an example of the recently observed optogalvanic effect in discharge plasmas. The coupling of level populations through radiative transitions and electron collisions is solved in a modified Schottky approximation for a glow discharge. The effects of radiation trapping, superelastic collisions, and buffer-gas pressures are treated in the analysis. The utilization of this effect for isotope separation is discussed.
Clinical index systems used to assess the efficacy of mouth‐rinses on plaque and gingivitis

The American Dental Association's Council on Dental Therapeutics has adopted Guidelines for acceptance of chemotherapeutic products for the control of supragingival dental plaque and gingivitis. The most widely used plaque indices are the plaque index (PI) and the Turesky index. Gingivitis has usually been assessed by the Loe and Silness method, although the modified gingival index of Lobene and a bleeding index reported by Caton and Polson have also been used. To date, 2 products have been accepted by the Council as being effective in helping control supragingival plaque and gingivitis. These products were evaluated using clinical indices described in this review. The indices were selected from the many in the literature as being valid, reliable, and easily learned. Suggestions are made for criteria to be used in comparability studies.
A Screening Methodology for VMIN Drift in SRAM Arrays with Application to Sub-65nm Nodes

SRAMs are an integral part of system on chip devices. With transistor and gate length scaling to 65nm/45nm nodes, SRAM stability across the product's lifetime has become a challenge. Negative bias temperature instability, defects, or other phenomena that may manifest itself as a transistor threshold voltage (VT) increase can result in VMIN drift of SRAM memory cells through burn-in and/or operation. A direct assessment at time-zero is difficult because the transistor VT has not yet shifted, and therefore no capability to screen VMIN shift at time zero can be developed. This work describes a methodology developed on 65nm low power and high performance process technologies at Texas Instruments for screening SRAM cells at time zero before they become reliability issues.
A shortened Child Behavior Checklist for delinquency studies.

This study examines the reduction of the number of items in the scales of the Child Behavior Checklist, while maintaining the reliability and predictability of its original scales. For that purpose, the original scales were replicated with data from the Pittsburgh Youth Study. New, abbreviated scales were constructed using the most potent items. This process yielded trimmed scales that were highly correlated with the full scales and that still reflect the original meanings of the scales. Further, there was no loss of reliability or predictability with the trimmed as opposed to the full scales. The results were replicated in an analysis with identical variables from the Rochester Youth Development Study. This replication produced equally high reliabilities with similar levels of prediction of delinquent behavior.
Bronchoscopy in tuberculosis; deformity of the major bronchi associated with high diaphragm rise in certain forms of non-surgical collapse therapy.

1) Collapse therapy to produce a diaphragm rise causes characteristic deformity of the main bronchi. Sharp dorsal angulation of the left main bronchus above the level of all lobe orifices on this side is especially significant. 2) The deformed left tree appears to favor the development of endobronchial disease. 3) Optimal diaphragm rise, rather than maximal rise, based on bronchoscopic observation of the individual case seems the more intelligent approach.
The Iterated Prisoner's Dilemma: early experiences with Learning Classifier System-based simple agents

Abstract Prior research on artificial agents/agencies involves entities using specifically tailored operational strategies (e.g., for information retrieval, purchase negotiation). In some situations, however, an agent must interact with others whose strategies are initially unknown and whose interests may counter its own. In such circumstances, pre-defining effective counter-strategies could become difficult or impractical. One solution, which may be viable in certain contexts, is to create agents that self-evolve increasingly effective strategies from rudimentary beginnings, during actual deployment. Using the Iterated Prisoner's Dilemma (IPD) problem as a generic agent-interaction setting, we use the Learning Classifier System (LCS) paradigm to construct autonomously adapting “simple” agents. A simple agent attempts to cope by maintaining an evolving but potentially perennially incomplete and imperfect knowledge base. These agents operate against specifically tailored (non-adaptive) agents. We present a preliminary suite of simulation experiments and results. The promise evidenced leads us to articulate several additional areas of interesting investigations that we are pursuing.
A leading index of drilling activity: Update and improvements

A five-component composite leading index of United States rotary rig drilling activity is updated. The index is presented for 1949 through April 1986 and is shown to consistently lead turning points in drilling activity. Seven new leading indices based on some new components are also presented. A forecast of drilling activity is made for the remainder of 1986 based on the leading index and the current economic condition of the petroleum industry. The methods used to prepare time series and construct indices are reviewed.
A numerical simulation of acrylic grout curing in a femoral implant

Abstract A numerical simulation of the thermal response of a femoral prosthesis-acrylic grout-bone composite during and after polymerization of the grout is presented. It is intended to model total hip replacement just after implantation of the prosthesis. The problem is formulated such that the governing energy equation depends only on the radial coordinate and time. The equations for the composite are solved numerically using finite differences. Time differencing is by the Crank-Nicolsen method. Results include thermal histories of the composite, emphasizing the grout-bone interface, as altered by various initial composite temperatures and the size and location of the grout. It is found that the grout-bone interface temperature can be dangerously large (50–90% above body temperature) and that this can be overcome by chilling of the metal prosthesis. Also, the amount of heat generated, thus the grout-bone interface temperature, is dependent on the volume of the grout and its location.
A contrast based image fusion technique in the DCT domain

Abstract This paper studies image fusion techniques in the discrete cosine transform (DCT) domain. A new image fusion technique based on a contrast measure defined in the DCT domain is presented. The performance of our contrast measure based technique is analyzed and compared with other image fusion techniques. Experimental results show that there is no difference in visual quality between the fused image obtained by our algorithm and that obtained by a wavelet transform based image fusion technique. But because our algorithm is carried out in the DCT domain, it is time-saving and simpler when the fused image needs to be saved or transmitted in JPEG format or when the images to be fused were saved in JPEG format.
Two-dimensional spectrally resolved position-sensitive proportional counter for plasma imaging

We describe a 160×100 mm two-dimensional position-sensitive proportional counter for use in high-temperature plasma spectroscopy. The detector employs a novel design based on a printed circuit board for the cathode plane and a single-wire switchback design for the anode plane. The spacial resolution for one dimension is 200 μm and for the other dimension is 2–5 mm. The integral nonlinearity is 0.08% for the first and 1% for the second dimension. We demonstrate the utility of the new detector with a spacially resolved measurement of the Lyman-α transitions in hydrogenic Ar17+.
Program analysis for compiler validation

Translation Validation is an approach of ensuring compilation correctness in which each compiler run is followed by a validation pass that proves that the target code produced by the compiler is a correct translation (implementation) of the source code. It has been previously shown that the problem of translation validation can be reduced to checking if a single system - the corss-product of the source and target, satisfies a specific property. In this paper, we show how to adapt the existing program analysis techniques in the setting of translation validation. In addition, we present a novel invariant generation algorithm which strengthens our analysis when the input programs contain dynamically allocated data structures. Finally, we report on the prototype tool that applies the developed methodology to verification of the LLVM compiler. The tool handles many of the classical intraprocedural compiler optimizations such as constant folding, reassociation, common subexpression elimination, code motion, dead code elimination, and others.
Light microscopic observations of alterations in staining of the zona pellucida of porcine follicular oocytes: Possible early indication of atresia

Serial sections of porcine ovaries were examined in an attempt to detect early signs of oocyte degeneration/atresia using special staining. Porcine ovaries were fixed in Bouin's fixative and embedded in paraffin using routine techniques. Serial sections (8 μm) were mounted on glass slides and stained with Shorr's S3 and hematoxylin stain. Several criteria were used for examining general histology of the antral follicles: condition of the granulosa layer, antral cavity, the oocyte and its surrounding zona pellucida, and the cumulus layers. A change in the staining characteristic of the zona pellucida was the single most striking observation in all ovaries examined. In presumably healthy follicles, the zona pellucida was uniformly stained green, the granulosa layer was intact with fewer than three pyknotic cells per section, and a uniform basement membrane (stained green) separated the intact theca layers from the remainder of the follicle. In those follicles showing some degree of degenerative changes in the follicular wall, the zona pellucida was stained a bright orange. In the last stages of degeneration, follicles exhibited many pyknotic nuclei throughout the granulosa layers, the layer of granulosa cells was in many cases separated from the basement membrane, and the antrum was infiltrated with lymphocytes. In these follicles, the zona pellucida was always stained orange. Frequently, the zona pellucida was partially stained orange before any detectable changes could be seen in other elements of the follicular wall. Additionally, many non-antral (primary) follicles exhibited oocytes with orange-stained zonae pellucidae. In terminal stages of follicular degeneration, collapsed follicles were infiltrated by connective tissue elements stained bright orange and green. These structures very often contained dying oocytes always with bright orange-stained zonae pellucidae. Scattered throughout the ovarian stroma were many orange-stained remnants of zonae pellucidae. It is thought that perhaps the characteristic staining of the zona pellucida with Shorr's S3 stain may give an early, previously undetectable indication of follicular atresia.
6-Hydroxymelatonin sulfate excretion in human puberty

We investigated the relationship of urinary excretion rate of 6-hydroxymelatonin sulfate (SM), the main metabolite of melatonin, with pubertal development and determined the day to day variability of SM excretion. Healthy subjects 4-31 years old completed one or multiple timed overnight urine collections. SM excretion rate per body size was significantly higher in 99 prepubertal subjects (35.5 +/- 2.3 ng/h/kg and 0.97 +/- 0.06 microgram/hr/m2) than in 86 pubertal subjects (18.1 +/- 1.1 ng/hr/kg and 0.61 +/- 0.03 microgram/hr/m2) or in 29 adults (15.0 +/- 1.5 ng/hr/kg and 0.59 +/- 0.06 microgram/hr/m2); no significant difference was present in pubertal stages 2 to 5. Among the prepubertal children, SM excretion rate in mid childhood was significantly higher than in late childhood. The variability of SM and creatinine excretion examined in 52 children, adolescents and adults with three or four collections was defined as the mean of the 52 coefficients of variation for the multiple measures in each subject. The variability of total nocturnal SM (25.9 +/- 2.6%) was similar to that of total creatinine (21.7 +/- 2.3%) and neither was significantly correlated with the variability in start time or duration of urine collection. The results suggest that, relative to body size, melatonin secretion rate is higher in mid childhood, decreases during late childhood, and remains stable from pubertal stage 2 to adulthood. The decline in melatonin secretion rate occurs during the developmental phase of disinhibition of the gonadotropin releasing hormone pulse generator. Hence, we infer that melatonin may be a suppressive factor of puberty during childhood. The substantial individual variability observed for SM excretion calls for caution in using single urine collections in longitudinal studies or in studies of drug responses.
TO THE BEAT OF A DIFFERENT DRUMMER- TIMING AND CONTEXTUAL DIFFERENCES OF MOBILE AND IMMOBILE MANAGERIAL CAREERS

This study used detailed career histories to explore the differences in career patterns between mobile and immobile managers. The timing of mobility events was examined along with movement direction and type. In addition, the study explored to what degree contextual factors associated with the career path, influenced such career patterns. Analysis showed unique differences in mobile and immobile career patterns and demonstrated that contextual factors play a significant role in shaping these patterns.
Immunohistologic analysis of gastrointestinal and pulmonary carcinoid tumors

Carcinoid tumors are potentially malignant neoplasms that arise in various body sites, including the lung and gastrointestinal tract. Those that appear cytologically atypical are more likely to behave aggressively than more typical carcinoid tumors. However, in the absence of cytological atypia or large tumor size, it is difficult to predict the biology of an individual tumor, because some lesions metastasize, whereas others do not. This study had four aims: (1) To study the expression pattern of p53, Ki-67, NCAM, and S-100 in carcinoid tumors and to relate these expression patterns to classical histopathologic features and to tumor location. (2) To identify nonhistological markers that might more accurately predict the early behavior of carcinoid tumors. (3) To determine whether sustentacular cells are present in carcinoid tumors arising in tissues derived from different embryological derivatives. (4) To determine the synaptophysin and chromogranin immunoreactivity in neuroendocrine tumors arising in various locations. The immunostaining reactions were quantitatively scored by three observers. Only 3 of the 39 tumors (all histologically atypical) were strongly positive for Ki-67; two of these were also strongly p53 immunoreactive. NCAM immunostaining differed according to the site of origin: 76.5% of foregut lesions, 58% of the midgut lesions, and 20% of hindgut lesions were positive. S-100 immunostaining ranged from 41% in foregut lesions to 50% in both the hindgut- and midgut-derived tumors. S-100-positive sustentacular cells were present in 20.5% of carcinoid tumors. All tumors stained with antibodies against synaptophysin. In contrast, 100% of midgut, 60% of hindgut, and 88% of foregut tumors were chromogranin positive. Carcinoid tumors tend to have low proliferative rates. p53 immunostaining tends to be strongly positive in tumors that are histologically atypical, but it is negative in typical carcinoid tumors arising in the gastrointestinal tract and lungs. Immunostaining reactions with antibodies to NCAM, S-100, and chromogranin differ depending on the site of origin. Synaptophysin stains 100% of carcinoid tumors regardless of their site of origin. In contrast, antibodies to chromogranin fail to stain 40% of hindgut tumors and 12% of foregut carcinoid tumors. S-100-positive sustentacular cells are present in foregut and midgut tumors but not in hindgut tumors.
Characterization of the Secondary Quinone (QB) Binding Pocket in Photosynthetic Reaction Centers Using Pulsed EPR Spectroscopy

3-pulse ESEEM and HYSCORE pulse sequences have been used to analyze the secondary electron acceptor semiquinone anion radical (QB-). Photosynthetic reaction centers from Rhodobacter sphaeroides have identical ubiquinone molecules functioning as primary and secondary electron acceptors. The primary quinone radical (QA-) has been extensively studied, and hydrogen bonds have been characterized at both carbonyls. The structure around QB- has received less attention. The O4 carbonyl has been suggested to be hydrogen bonded to the Nδ from a histidine at residue L190. The O1 carbonyl also possesses a hydrogen bond that is weaker than that at O4. OH from serine at L223 is important in the hydrogen bond structure at this carbonyl. However, contributions from surrounding peptide nitrogens are suggested by x-ray structures but have not yet been investigated by EPR methods. Pulsed EPR studies of the QB- radical confirm one strongly coupled nitrogen with NQI frequencies consistent with a histidine Nδ. 3-pulse ESEEM and HYSCORE spectra also contain peaks from a second nitrogen nucleus. A priori knowledge of the origins of these peaks is less clear, but could include contributions from a backbone nitrogen. Additionally, NQI modulation from 14N is sufficiently shallow to observe signals from 2 protons in HYSCORE measurements. These results suggest the possibility that an additional residue contributes to the stability of QB-. Supported by NSF grant MCB 08-18121.
Autonomous docking experiments using the SPHERES testbed inside the ISS

This paper presents recent results regarding the research on autonomous docking with tumbling targets performed by the MIT Space Systems Laboratory (SSL). The objective of this research is to develop a guidance, navigation and control (GN&C) architecture that enables safe and fuel efficient docking of a thruster-based spacecraft with a tumbling target in the presence of obstacles and contingencies. Over the calendar year 2006, experiments were performed inside the International Space Station (ISS) using the SPHERES nano-satellites to validate a GN&C architecture on hardware in microgravity. A series of attitude slews, an autonomous docking maneuver with a fixed beacon and a station-keeping maneuver were among the experiments carried out in May to validate subsets of the architecture with only a fraction of the SPHERES hardware. The second set of experiments occurred in August and involved two satellites and the remaining navigation hardware. The global estimator allowing the SPHERES to navigate within the US Laboratory was validated. Multiple successful docking maneuvers between two satellites were also accomplished. In November, more complex docking scenarios were experimented, leading to the first successful autonomous docking with a tumbling target ever performed in microgravity. Results collected during key ISS experiments are presented in this paper.
Transmissible drug resistance of Escherichia coli and Salmonella from humans, animals, and their rural environments.

Isolates of Escherichia coli and Salmonella species obtained from humans, animals, and their rural environments were tested for their ability to transfer multiple drug resistance to competent recipients. In all, 125 (52.9%) of 242 isolates of E.coli transferred all or part of their resistance to E.coli CSH-2, and 103 (44.4%) of 232 isolates of E.coli transferred all or part of their resistance to Salmonella choleraesuis var. kuzendorf 214. The data suggest that the multiple drug resistance of E.coli transferred all or part of their resistance to Salmonella choleraesuis var kuzendorf 214. The data suggest that the multiple drug resistance of E. coli in the gut of humans who work with livestock may be due to the transfer of resistance determinants from animal strains to the resident flora of the human gut. Such transfer could occur during transient passage through the digestive tract. Multiple drug-resistant Salmonella were isolated from all sources. In all, 48 (80%) of 60 isolates of Salmonella transferred all or part of their resistance to E. coli CSH-2, and isolates of Salmonella transferred all or part of their resistance to E.coli CSH-2, and 42 (82.4%) of 51 isolates of Salmonella transferred all or part of their resistance to S. choleraesuis var, kuzendorf 214. Fifty-three (46.9%) of 113 antibiotic-sensitive isolates of E.coli possessed resistance transfer factor, and six (23.1%) of 26 isolates with resistance transfer factor mobilized resistance determinants in isolates unable to transfer drug resistance during conjugation experiments.
International Diversification and the Nature of Value Creation: A Real Options Perspective

Firms pursue international diversification to create value. According to real options theory, firm value can be associated with assets-in-place or future growth opportunities. The markets that the firm selects play a critical role in determining the nature of firm value created from international expansion. We examine how the location of diversification influences the nature of firm value. Based on real options theory, we argue that for U.S. firms, international diversification into emerging economies will likely increase growth option value given the higher upside potential and associated higher endogenous and exogenous uncertainty. In contrast, expansion into advanced economies will likely be associated with assets-in-place value. Using a sample of 672 firms from the S&P 1,500 over a period of 9 years, we find support for these arguments. We also examine the focus of the firm’s diversification strategies within emerging and advanced economies on value creation. We find that greater within-economy divers...
Additive Protection of the Ischemic Heart Ex Vivo by Combined Treatment With δ-Protein Kinase C Inhibitor and ε-Protein Kinase C Activator

Background— Protein kinase C (PKC) plays a major role in cardioprotection from ischemia/reperfusion injury. Using an HIV-1 Tat protein–derived peptide to mediate rapid and efficient transmembrane delivery of peptide regulators of PKC translocation and function, we examined the cardioprotective effect of selective δ-PKC inhibitor (δV1-1) and e-PKC activator (ψeRACK) peptides for ischemia/reperfusion damage in isolated perfused rat hearts. Furthermore, we examined the protective effects of these PKC isozymes in isolated perfused hearts subjected to ischemia/reperfusion damage using transgenic mice expressing these peptides specifically in their cardiomyocytes. Methods and Results— In isolated perfused rat hearts, administration of δV1-1 but not ψeRACK during reperfusion improved cardiac function and decreased creatine phosphokinase release. In contrast, pretreatment with ψeRACK but not δV1-1, followed by a 10-minute washout before ischemia/reperfusion, also improved cardiac function and decreased creatine p...
Paleoceanographic implications of terrigenous deposits on the Maurice Ewing Bank, southwest Atlantic Ocean

Abstract Grain size distributions of sediment samples from the Maurice Ewing Bank (MEB) were utilized to identify styles of sediment transport and to estimate current speeds within the benthic boundary layer. These data allow for examination of the relationship between sedimentation on the bank and circumpolar currents. Causal relationships between glacial episodes, current intensification, and bottom current scour were previously postulated. The intent of this study was to test the validity of these suggested relationships. Modern sediment distribution on the MEB is controlled by water column winnowing, bottom currents, and variations in the flux of ice-rafted detritus and biogenic material, and is modified by mass-flow processes. Indirect determinations of current speeds, using well established curves relating current velocity to sediment transport, suggest uniform, near-bottom current speeds of approximately 6–15 cm s −1 over the bank. This velocity range is considered relative, not absolute. Nonetheless, these moderate velocities are supported by geostrophic velocity calculations. Grain size distributions of down-core samples from Plio-Pleistocene sandy units were examined in order to investigate the history of bottom current flow over the bank during this time. The lack of significant variability of grain size distributions down-core indicates that no major fluctuations in circumpolar current intensification have occurred since Plio-Pleistocene time, and, therefore, argue against a causal relationship between glacial conditions and deep-sea (geostrophic) current intensification. In addition, mass movement, mainly in the form of debris flows and turbidites, has resulted in interruptions in the sedimentary record, which in some cases could have been misinterpreted as unconformities. Our scenario for sedimentation over the bank differs from previous ones in that it calls for less dramatic variations in bottom current speeds during Pliocene—Holocene time.
High Density Plasma Neutralization of a Hall Thruster

In the attempt to fill the performance niche between the arcjet and Hall thruster, we propose the use of a helium arcjet to neutralize Hall thrusters. Since the arcjet is a high plasma density device, one arcjet can potentially neutralize a cluster of Hall thrusters. In this preliminary study, we used a surrogate planar anode in the place of a Hall thruster anode to determine the effects of drawing electron current from a low power arcjet plume on the operation and performance of the arcjet. In all tests we are able to draw currents to the surrogate anode that were greater than the arc current. It is found that biasing the surrogate anode does lead to a perturbation in the arcjet discharge voltage, in some cases resulting in a voltage decrease of up to 40%. The helium arcjet exhibits arc voltage instabilities in the same spectral range of the instabilities that are intrinsic in Hall thrusters. We find however, that these arcjet instabilities decreased in strength and in bandwidth when a bias is applied to the anode. The effect of biasing on the overall arcjet performance (e.g., thrust, specific impulse) is still under investigation. However, preliminary studies made using an impact pressure probe confirms that there is little compromise in the arcjet thrust during the current draw. The use of laser-induced fluorescence to measure the velocity of the arcjet plume flowfield during an applied bias was hindered by the finding that the lower energy state of the helium transition used for the LIF measurements was effectively depopulated by the biasing a result supported by optical emission measurements of the plume.
Microarray-based global differential expression profiling of P450 monooxygenases and regulatory proteins for signal transduction pathways in the white rot fungus Phanerochaete chrysosporium

Whole genome sequencing of the model white rot basidiomycete Phanerochaete chrysosporium has revealed the largest P450 contingent known to date in fungi, along with related phase I and phase II metabolic genes and signaling cascade genes. As a part of their functional characterization, genome-wide expression profiling under physiologically distinct conditions, nutrient-limited (ligninolytic) and nutrient-rich (non-ligninolytic), was investigated using a custom-designed 70-mer oligonucleotide microarray developed based on 190 target genes and 23 control genes. All 150 P450 genes were found to be expressible under the test conditions, with 27 genes showing differential expression based on a >twofold arbitrary cut-off limit. Of these, 23 P450 genes were upregulated (twofold to ninefold) in defined high-nitrogen cultures whereas four genes were upregulated (twofold to twentyfold) in defined low-nitrogen cultures. Furthermore, tandem P450 member genes in ten of the 16 P450 genomic clusters showed nonassortative regulation of expression reflecting their functional diversity. Full-length cDNAs for two of the high-nitrogen upregulated genes pc-hn1 (CYP5035A1) and pc-hn2 (CYP5036A1) and partial cDNA for a low-nitrogen upregulated gene pc-ln1 (CYP5037A1) were cloned and characterized. The study provided first molecular evidence for the presence of active components of the cAMP- and MAP kinase-signaling pathways in a white rot fungus; four of these components (cpka and ste-12 of cAMP pathway and two MAP kinases, mps1 and sps1) were significantly upregulated (fourfold to eightfold) under nutrient-limited conditions, implying their likely role in the regulation of gene expression involved in secondary metabolism and biodegradation processes under these conditions.
Cyclin A2 and its associated kinase activity are required for optimal induction of progesterone receptor target genes in breast cancer cells

A role for the cell cycle protein cyclin A2 in regulating progesterone receptor (PR) activity is emerging. This study investigates the role of cyclin A2 in regulating endogenous PR activity in T47D breast cancer cells by depleting cyclin A2 expression and measuring PR target genes using q-RT-PCR. Targets examined included genes induced by the PR-B isoform more strongly than PR-A (SGK1, FKBP5), a gene induced predominantly by PR-A (HEF1), genes induced via PR tethering to other transcription factors (p21, p27), a gene induced in part via extra-nuclear PR signaling mechanisms (cyclin D1) and PR-repressed genes (DST, IL1R1). Progestin induction of target genes was reduced following cyclin A2 depletion. However, cyclin A2 depletion did not diminish progestin target gene repression. Furthermore, inhibition of the associated Cdk2 kinase activity of cyclin A2 also reduced progestin induction of target genes, while Cdk2 enhanced the interaction between PR and cyclin A2. These results demonstrate that cyclin A2 and its associated kinase activity are important for progestin-induced activation of endogenous PR target genes in breast cancer cells.
Studies on the kinetics and mechanism of orthophosphate activation of bovine brain hexokinase.

Abstract The binding of glucose to bovine brain hexokinase, isozyme I, exhibited one binding site per 100,000 molecular weight. Glucose-6-P binding was examined in the absence and presence of ATP. ATP and glucose-6-P were shown to compete for the same binding site on the enzyme. A model was proposed to account for these findings and the previously reported data that glucose-6-P and Pi exhibit mutually exclusive, non-cooperative binding to the enzyme. The model shows that brain hexokinase exists in two rapidly interconvertible states, either with or without Pi and that glucose-6-P binding to the phosphate associated enzyme form is relatively very poor. This proposal has been tested kinetically and the data appear to support the suggested model.
Low-Level Jets, Orographic Effects, and Extreme Events in Nares Strait: A Model-Based Mesoscale Climatology

Abstract A mesoscale atmospheric model, nested in operational global numerical weather prediction fields, is used to estimate low-level winds and surface wind stress through Nares Strait, between Ellesmere Island and Greenland, during 2 yr from August 2003 to July 2005. During most of the year, the model low-level winds are dominated by intense, southward along-strait flow, with monthly-mean southward 10-m winds reaching 10 m s−1 in winter. Summertime flow is weak and distributions of hourly along-strait winds during the 2-yr period are strongly bimodal. The strong southward low-level winds are associated with ageostrophic, orographically channeled flow down the pressure gradient from the Lincoln Sea to Baffin Bay and are highly correlated with the pressure difference along Nares Strait. The 2-yr means and leading EOFs of monthly-mean 10-m winds and wind stress place the strongest winds and stress in the southern parts of Smith Sound and of Kennedy Channel, at the openings to Baffin Bay and Kane Basin, at...
Qualitative imaging of adeno-associated virus serotype 2-human aromatic L-amino acid decarboxylase gene therapy in a phase I study for the treatment of Parkinson disease.

Background Putaminal convection-enhanced delivery (CED) of an adeno-associated virus serotype 2 (AAV2) vector, containing the human aromatic L-amino acid decarboxylase (hAADC) gene for the treatment of Parkinson disease (PD), has completed a phase I clinical trial. Objective To retrospectively analyze magnetic resonance imaging (MRI) and positron emission tomography (PET) data from the phase I trial, correlate those data with similar nonhuman primate (NHP) data, and present how such information may improve future PD gene therapy trials in preparation for the initiation of the phase II trial. Methods Ten patients with PD had been treated with bilateral MRI-guided putaminal infusions of AAV2-hAADC. MRI and PET scans were obtained at baseline (before vector administration) and at various intervals after treatment. Three normal adult NHPs received similar infusions into the thalamus. Imaging studies for both groups are presented, as well as hAADC immunohistochemistry for the NHPs. Results Early post-CED MRI confirmed the stereotactic targeting accuracy and revealed T2 hyperintensity around the distal cannula tracts, best seen within 4 hours of surgery. Coregistration of post-CED MRI and PET scans revealed increased PET uptake at the sites of T2 hyperintensity. Similar T2 hyperintensities in NHP MRI correlated with hAADC immunohistochemistry. Conclusion Our analysis confirms the correct targeting of the CED cannula tracts within the target human putamen. Coregistration of MRI and PET confirms colocalization of T2 hyperintensities and increased PET uptake around the distal cannula tracts. Because PET uptake closely correlates with hAADC transgene expression and NHP data confirm this relationship between T2 hyperintensity and hAADC immunohistochemistry, we believe that T2-weighted MRI allows visualization of a significant part of the distribution volume of the hAADC gene therapy. Recommendations for future protocols based on these data are presented.