cssi/SciSciGPT-SciSciNet huggingface dataset:
Probability Theory and Multiexponential Signals, How Accurately Can the Parameters be Determined?

Estimating the amplitudes and decay rate constants of exponentially decaying signals is an important problem in science. Understanding how the uncertainty in the parameter estimates depends on the experimental parameters is important as an aid in understanding how to improve the reliability of the parameter estimates. In this paper, probability theory has been applied to this problem with the intent of understanding the relevant experimental parameters. In the case of a single exponential, the uncertainty in the estimated decay rate depends directly on the three halves power of the true decay rate constant, inversely on the signal-to-noise ratio, and inversely on the square root of the number of data values. The uncertainty in the amplitude estimate depends directly on the square root of the true decay rate constant, directly on the noise level, and inversely on the square root of the number of data values. The case of two exponentials has also been analyzed with similar results. However, here the presence of the second signal introduces interference effects which make the estimate more uncertain.
Variable ultraviolet absorption in the spectrum of MR 2251-178

We present an ultraviolet spectrum of MR 2251-178 taken with Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) with the G230L grating. The observation is part of a snapshot program of quasars (QSOs) that systematically searches for intrinsic absorption lines through variability. The sample consists of all QSOs observed with the HST/Faint Object Spectrograph (FOS) that showed associated narrow absorption lines. The FOS spectrum of MR 2251-178, taken in 1996, showed an associated C IV doublet with a λ1548 equivalent width of 1.09 ± 0.09 A. It is not detected in the STIS spectrum taken 4 years later, down to a 3 σ threshold of 0.19 A. In addition to its other accolades, these observations make MR 2251-178 the very first QSO at low redshift in which the associated absorption is shown to be truly intrinsic. We discuss the implications of this and suggest courses for future study.
The partial weight-bearing rat model using a pelvic harness does not impact stress or hindlimb blood flow

Abstract Aim Future space missions will send humans to the Moon and Mars, where gravity is greatly reduced compared to Earth. The recent development of a rat partial weight-bearing (PWB) model allowed for a better understanding of the changes induced by reduced loading. Method We exposed animals to 28 days of PWB including: normal loading without apparatus (PWB100 N), normal loading with full apparatus (PWB100 FH), 70%, 40%, and 20% of normal loading (PWB70, PWB40, and PWB20, respectively). We assessed physiological parameters weekly (i.e.: tail blood pressure, hindlimb oxygen saturation, plasma corticosterone) to measure the impact of the apparatus during normal loading, and to determine if PWB resulted in a dose-dependent modification of stress and/or hindlimb blood pressure. In addition, we sought to determine if forelimb muscle atrophy could be detected. Results The use of the full apparatus did not impact any parameters compared to the control group during normal loading, except for a reduced weight gain. PWB did not lead to significant modifications of animals’ blood pressure, blood oxygenation, or stress markers. Indeed, after 28 days of PWB, plasmatic corticosterone levels were of 39.8 ± 12.0, 47.0 ± 16.9, 69.5 ± 14.4 and 55.9 ± 17.7 ng/mL in animals exposed to PWB100, PWB70, PWB40 and PWB20, respectively (p = 0.7577). Conclusion These results support our hypothesis that our rat PWB system using a pelvic harness is well tolerated by the animals and does not initiate a chronic-stress state that could mask other physiological alterations.
An Ephemerally Self-Exciting Point Process

Across a wide variety of applications, the self-exciting Hawkes process has been used to model phenomena in which the history of events influences future occurrences. However, there may be many situations in which the past events only influence the future as long as they remain active. For example, a person spreads a contagious disease only as long as they are contagious. In this paper, we define a novel generalization of the Hawkes process that we call the ephemerally self-exciting process. In this new stochastic process, the excitement from one arrival lasts for a randomly drawn activity duration, hence the ephemerality. Our study includes exploration of the process itself as well as connections to well-known stochastic models such as branching processes, random walks, epidemics, preferential attachment, and Bayesian mixture models. Furthermore, we prove a batch scaling construction of general, marked Hawkes processes from a general ephemerally self-exciting model, and this novel limit theorem both provides insight into the Hawkes process and motivates the model contained herein as an attractive self-exciting process in its own right.
Chapter 10 – Synthesis of Organometallic Compounds

Organometallic chemistry is an important field that combines organic ligands with inorganic metal centers. These complexes are diverse as are the techniques employed to make them. This chapter will cover the general reactions used to synthesize organometallic complexes such as substitution and insertion reactions. Next, an overview will be given on the preparation of different classes of organometallic complexes such as carbonyls, hydrides, alkyls, carbenes, carbynes, and paramagnetic complexes. Lastly, some air-sensitive techniques are covered since many of these complexes react readily with air and water and must be handled in an inert environment.
An experimental investigation of thermally induced flow instabilities in a convective boiling upflow system

The two-phase flow instabilities in a single channel, forced convection, open loop, up-flow system have been investigated experimentally using R-11 as the working fluid. The effects of mass flow rate, heat input, inlet liquid temperature and upstream compressible volume on two-phase flow instabilities have been investigated. Two heater surfaces were tested at five different heat inputs with constant inlet temperature, and four different inlet temperatures with constant heat input. For each case, the mass flow rate was varied over a wide range covering the entire scope for boiling two-phase flows. Experiments were also conducted at different compressible volumes, with constant heat input, inlet fluid temperature, and average mass flow rate. The oscillations of inlet mass flow rate, heater inlet pressure, and heater wall temperature were recorded. The effects of mass flow rate, inlet liquid temperature and heat input on the amplitudes and periods of inlet pressure and thermal oscillations are presented in tabular and graphical forms.
Understanding practice variation with a clinical pathways system: Differences by physician and practice factors, and changes in practice over time.

2079Background: Clinical oncology pathways aim to support clinical decision-making and reduce unwarranted practice variation across an enterprise. The Dana-Farber Cancer Institute (DFCI) implemente...
Damage effect of helium ion on solid sample during observation through HIM

In the usage of the field of observation using field ion microscope, researches are mainly focusing on the performance of the scope. Although ion beams can be also used as beam cutters in the industry [1], not many works address the question of whether the field ion microscope can how much damage an observation object. In this paper, we are using a certified accurate model in an ion shooting simulation software SRIM to verified various damage events created by helium ion beams with a certain level of energy, which will be set to the normal working load on an existing helium ion microscope, shooting on a coated material. [2] By analyzing the damage events brought by the high energy workload helium ion beam, we expect that we can approach a main trends that show how much damage an observation object would have under a normal helium ion microscope.
Single-cell analysis of ductal differentiation.

A microwell chip facilitates the differentiation of aggregates of human induced pluripotent stem cells into pancreatic-duct-like organoids and the characterization of the differentiation process at the single-cell level.
Neural Operator: Learning Maps Between Function Spaces.

The classical development of neural networks has primarily focused on learning mappings between finite dimensional Euclidean spaces or finite sets. We propose a generalization of neural networks tailored to learn operators mapping between infinite dimensional function spaces. We formulate the approximation of operators by composition of a class of linear integral operators and nonlinear activation functions, so that the composed operator can approximate complex nonlinear operators. We prove a universal approximation theorem for our construction. Furthermore, we introduce four classes of operator parameterizations: graph-based operators, low-rank operators, multipole graph-based operators, and Fourier operators and describe efficient algorithms for computing with each one. The proposed neural operators are resolution-invariant: they share the same network parameters between different discretizations of the underlying function spaces and can be used for zero-shot super-resolutions. Numerically, the proposed models show superior performance compared to existing machine learning based methodologies on Burgers' equation, Darcy flow, and the Navier-Stokes equation, while being several order of magnitude faster compared to conventional PDE solvers.
A Comprehensive Analysis of Complications of Free Flaps for Oromandibular Reconstruction.

OBJECTIVES/HYPOTHESIS To determine the frequency and management of short- and long-term complications related to oromandibular free flap reconstruction and identify potentially predictive factors of hardware complications. STUDY DESIGN Retrospective chart review. METHODS A retrospective database from chart review was formed consisting of 266 oromandibular free flap reconstructions performed at a single institution over a 15-year period. Data were collected on demographics, surgical treatment, complications, and management of complications. Subgroup univariate and multivariate analyses were performed to compare patients with hardware complications and those without. RESULTS Eighty-one of 266 patients (30.5%) that underwent oromandibular reconstruction had an early complication ( 4 weeks after surgery) and the most common complication was plate exposure (26.7%). Univariate and multivariate analyses showed no association between whether there was hardware extrusion and fibula versus scapula, smoking history, virtual surgical planning (VSP), and dental implantation (P > .05). Only early complications (OR, 3.59, 95% CI, 1.83-7.05, P < .01) and patients undergoing oromandibular reconstruction for osteoradionecrosis (OR, 2.26, 95% CI, 1.10-4.64, P = .03) were strongly and independently associated with subsequent hardware extrusion on univariate analysis. CONCLUSIONS Both short- and long-term complications are common after oromandibular reconstruction. The most important predictive factor for a late complication is an early complication and prior radiation. There was no difference of plate complications among the various free flap types. Dental implantation and use of VSP were not associated with hardware complications. LEVEL OF EVIDENCE 4 Laryngoscope, 131:1997-2005, 2021.
Architecture and assembly mechanism of native glycine receptors.

Glycine receptors (GlyRs) are pentameric, ‘Cys-loop’ receptors that form chloride-permeable channels and mediate fast inhibitory signaling throughout the central nervous system1,2. In the spinal cord and brainstem, GlyRs regulate locomotion and cause movement disorders when mutated2,3. However, the stoichiometry of native GlyRs and the mechanism by which they are assembled remain unclear, despite extensive investigation4–8. Here we report near-atomic resolution structures of native GlyRs from porcine spinal cord and brainstem, revealing the first structural insight into heteromeric receptors and their predominant stoichiometry of 4 α subunits:1 β subunit. Within the heteromeric pentamer, the β(+)/α(-) interface adopts a structure that is distinct from the α(+)/α(-) and α(+)/β(-) interfaces. Furthermore, the β subunit harbors a unique phenylalanine residue that resides within the pore and disrupts the canonical picrotoxin site. These results explain why inclusion of the β subunit breaks receptor symmetry and alters ion channel pharmacology. We also find incomplete receptor complexes and, by elucidating their structures, reveal the architectures of partially assembled α trimers and α tetramers for the first time.
Colorectal Cancer Screening in the Era of the Affordable Care Act.

The Affordable Care Act (ACA) eliminated cost-sharing for evidence-based preventive services in an effort to encourage use. To evaluate use of colorectal cancer (CRC) screening in a national population-based sample before and after implementation of the ACA. Repeated cross-sectional analysis of the Medical Expenditure Panel Survey (MEPS) between 2009 and 2012 comparing CRC screening rates before and after implementation of the ACA. Adults 50–64 with private health insurance and adults 65–75 with Medicare. Self-reported receipt of screening colonoscopy, sigmoidoscopy, or fecal occult blood test (FOBT) within the past year among those eligible for screening. Our study included 8617 adults aged 50–64 and 3761 adults aged 65–75. MEPS response rates ranged from 58 to 63%. Among adults aged 50–64, 18.9–20.9% received a colonoscopy in the survey year, 0.59–2.1% received a sigmoidoscopy, and 7.9–10.4% received an FOBT. For adults aged 65–75, 23.6–27.7% received a colonoscopy, 1.3–3.2% a sigmoidoscopy, and 13.5–16.4% an FOBT. In adjusted analyses, among participants aged 50–64, there was no increase in yearly rates of colonoscopy (−0.28 percentage points, 95% CI −2.3 to 1.7, p = 0.78), sigmoidoscopy (−1.1%, 95% CI −1.7 to −0.46, p = <0.001), or FOBT (−1.6%, 95% CI −3.2 to −0.03, p = 0.046) post-ACA. For those aged 65–75, rates of colonoscopy (+2.3%, 95% CI −1.4 to 6.0, p = 0.22), sigmoidoscopy (+0.34%, 95% CI 0.88 to 1.6, p = 0.58) and FOBT (−0.65, 95% CI −4.1 to 2.8, p = 0.72) did not increase. Among those aged 65–75 with Medicare and no additional insurance, the use of colonoscopy rose by 12.0% (95% CI 3.3 to 20.8, p = 0.007). Among participants with Medicare living in poverty, colonoscopy use also increased (+5.7%, 95% CI 0.18 to 11.3, p = 0.043). Eliminating cost-sharing for CRC screening has not resulted in changes in the use of CRC screening services for many Americans, although use may have increased in the post-ACA period among some Medicare beneficiaries.
Von Beta zu wilden Enten

Sie haben vielleicht schon mitbekommen, dass ich ein Buch geschrieben habe. Dafur sind Sie eigentlich mitverantwortlich. Das sollen Sie hiermit wissen.
Critical Frequencies in the Stagnation Region of a Shock Layer

To FACILITATE the estimating of stagnation-re gion plasma and electron, neutral-particle collision frequencies, a plot of alti­ tude versus velocity- with equilibrium plasma and collision fre­ quencies indicated parametrically was developed. Since the gas in the stagnation region is relatively dense and only weakly ionized, a so-called critical frequency is introduced to account for the influence of these elastic collisions. Alteration of the plasma frequency, when collisions are considered, is indicated on the above-mentioned plot. The term "plasma," as used here, refers to an electrically neutral, ionized gas consisting of equal populations of electrons and ions, and neutral particles also. The assumption of elec­ trical neutrality implies that the effects of space-charge forces, namely internally generated electric fields, are not important at distances comparable to the shortest length of interest. In the case of electromagnet ic radiation, this length is the wavelength of the radiation considered. It is well known that a character­ istic frequencj^, called the plasma frequency, co2„ is associated with each plasma, namely,
Born-International SMEs: BI-Level Impacts of Resources and Intentions

The Katz and Gartner (1988) model describes four central properties of emerging organizations: resources, intention, exchange, and boundary. While designed as a general model for organizations, the approach has the potential to explain the early lives of "born-international" firms. In this study, boundary is used to define the central sampling frame. Two other properties, resources and intention, are evaluated in terms of their impact on the fourth property: exchange, measured as a firm's export growth and intensity. Given the inherent presence of two levels of analysis in emerging organizations, intention and resources are evaluated at both the individual and the organizational level. A sample (N = 47) of young "born-international" firms in the Indian software industry was studied, using a questionnaire. Results of the analysis are mixed for resources at both the individual and firm level variables. Intention is significant at the individual level but not the firm level. Contrary to other studies, these findings suggest that during the early stages of firm development, owner, not firm, characteristics play a pivotal role in performance, especially exports. The speculation is that this occurs because, in early stages, firms are relatively disorganized relative to the owner.
Connections Through a Matrix

Proofs and Confirmations The Story of the Alternating Sign Matrix Conjecture. David M. Bressoud. Cambridge University Press, New York, and Mathematical Association of America, Washington, DC, 1999. 290 pp. $74.95. ISBN 0-521-66170-6. Paper, $29.95. ISBN 0-521-66646-5. Bressoud offers an account of the search for a proof of an early 1980s conjecture on objects that generalize permutation matrices. Although this recent development in algebraic combinatorics can seem quite impenetrable, he succeeds in making it clear and provides an informative illustration of how mathematical research progresses.
What Has Financed Government Debt

Dynamic rational expectations models imply that the real value of debt in the hands of the public must be equal to the expected present-value of surpluses. We impose this equilibrium condition on an identified VAR and characterize the way in which the present-value support of debt varies across various types of fiscal policy shocks and between fiscal and non-fiscal shocks. The role of expected primary surpluses in supporting innovations to debt depends on the nature of the shock. For some fiscal policy shocks, debt is supported almost entirely by changes in the present-value of surpluses, however, in the case of other fiscal policy shocks, surpluses fail to adjust and instead leave a large role for expected changes in discount rates. Horizons over which debt innovations are financed are long - on the order of fifty years - while present-values calculated up to any finite horizon up to then fluctuate wildly, particularly following government spending and transfer shocks.
Quasar Absorption Lines and High Redshift Galaxies

If metal-line systems occur only where the line of sight to a QSO intercepts a galaxy, we already have information on many hundreds of galaxies at redshifts greater than unity. Here we review research on the connection between galaxies and absorption line systems seen in QSO spectra. Most information about absorption due to galaxies is confined to low-ionization species because strong high-ionization transitions are limited to the vacuum UV. Conversely, the bulk of information about QSO metal-line systems comes from redshifts where galaxies are difficult to observe and may be, due to evolution, very different from present day galaxies. Studies underway to bridge this gap include comparisons of the velocity structure of individual absorbers and galaxies and their clustering, both spatial and in velocity, as well as the galaxian environment of QSO absorbers, and the composition and ionization state of the gas in QSO absorption systems versus galactic coronal clouds. These tend to indicate differences between the properties of high-z QSO absorbers and low-z galaxies, suggesting recent evolution in the population causing the absorption.
Evaluation of Alternative Alphanumeric Keying Logics

Four keying logics for the entry of alphanumeric characters were evaluated. Selection of the logics was based on their compatibility with current keyboard designs used in the pilot-aircraft interface, which involves communications, navigation, and other aircraft subsystems. subjects in each of four groups learned one of the logics and their performance was recorded on an alphanumeric keying task. Performance measures were keying speed and keying accuracy for alphabetic characters, numeric characters, character strings, and total list. Keying time for a keying logic that used 36 individual keys for each alphabetic and numeric character was significantly superior to other logics that used push-button telephone-type keyboards. Subjects were equally accurate on all logics.
Responsibility and Planning

We are planning agents and we are, or so we suppose, responsible agents. How are these two distinctive aspects of our agency related? In his "Freedom and Resentment" Peter Strawson understands responsible agency in terms of "reactive attitudes" like resentment and gratitude, attitudes which are normally embedded in "ordinary inter-personal relationships." I draw on Strawson's account to sketch an answer to my question about responsibility and planning. First, the fact that an action is plan-embedded can influence the agent's degree of culpability for that action; for such embeddings can constitute or indicate important facts about the quality of the agent's will. Second, general planning incapacities can to some extent exempt an agent from normal judgments of responsibility. My argument for this second claim appeals to the normal roles of planning in "ordinary inter-personal relationships."
Lunar Gravity from Orbiter Tracking Data

A procedure for extracting gravity information from lunar orbiter tracking data is described with particular attention to the photographic orbiter to be launched shortly by the United States.
The perceptual consequences of binaural hearing

Binaural processing in normal hearing activities is based on the ability of listeners to use the information provided by the differences between the signals at the two ears. The most prominent differences are the interaural time difference and the interaural level difference, both of which depend on frequency. This paper describes the stages by which these differences are estimated by the physiological structures of the auditory system, summarizes the sensitivity of the human listener to these differences, and reviews the nature of the interaural differences in realistic environments.
Prenatal mercury exposure, autism, and developmental delay, using pharmacokinetic combination of newborn blood concentrations and questionnaire data: a case control study

Methylmercury (MeHg), known for well over a century as a neurotoxin in adults, has more recently been studied for potential detrimental effects during early brain development. While several studies have estimated mercury exposure, they usually rely on either a single biomarker or questionnaire data, each of which has limitations. The goal of this paper was to develop a toxicokinetic model that incorporates both biomarker and questionnaire data to estimate the cumulative exposure to MeHg through seafood consumption using data collected from the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. We utilized a previously described discrete-time model that estimates blood MeHg concentration given a piecewise-constant ingestion rate and single-compartment pharmacokinetics. We measured newborn bloodspot Hg concentrations and obtained information pertaining to maternal fish consumption using a questionnaire. Using MeHg concentration estimates from the toxicokinetic model, cumulative MeHg exposure was estimated in children with autism, children with developmental delay, and typically developing children. Median estimated cumulative MeHg was compared among diagnostic groups using the Kruskal-Wallis Test. Multinomial logistic regression models were constructed to assess the association between cumulative MeHg concentration and the risk of autism and developmental delay (vs. typical development). The estimated average MeHg concentration of for all fish species consumed by mothers was 42 ppb. Median cumulative MeHg over gestation was similar across diagnostic groups (p-values raged from 0.91 to 0.98). After adjusting for potential confounding, we found no association between cumulative MeHg exposure and the risk of autism (OR = 0.95, 95 % CI: 0.95, 1.12) or developmental delay (OR = 1.00, 95 % CI: 0.89, 1.13). The toxicokinetic model described in this paper yielded fish MeHg concentration estimates that are consistent with fish species containing lower levels of MeHg. Overall, cumulative MeHg exposure does not appear to detectably elevate the risk of autism or developmental delay. Based on the regression standard error for the association between ASD and TD, we would have reported statistical significance for an adjusted odds ratio of 1.09 or larger. This method can easily be extended to other epidemiologic studies in which there is a biomarker measurement and questionnaire data regarding exposure.
YOUNG PEOPLE'S EXPERIENCES IN YOUTH-LED PARTICIPATORY ACTION RESEARCH FOR HIV/AIDS PREVENTION

As part of a project in the UNICEF-initiated “What every adolescent has a right to know” (RTK) program, qualitative interviews were conducted with youth (13 to 21 years of age) who were reached through a youth-led participatory action research (PAR) project. The interviews were conducted with both urban and rural participants in a Caribbean country where potential exposure to HIV/AIDS represents a significant threat to young people’s health. The purpose of the study was to examine how a truly youth organized PAR effort was perceived by the adolescents who were reached through the project. The results suggest that the central role played by youth researchers (the PAR community leaders) created a mode of participation that facilitated the collaboration of at-risk and marginalized youth. The type of engagement created was distinct from modes of participation fostered when adults alone worked with youth.
Exposure to violence and aggression: protective roles of social support among urban African American youth

This cross-sectional study examined the impact of social support on the relation between exposure to violence and aggressive behavior, as reported by self, peers, and teachers. The main-effects and stress-buffering models of social support were tested for parents, teachers, classmates, and close friends among 127 urban, African American youth. The results demonstrate the negative impact of violence exposure on aggressive behavior and the complex roles of social support in these relations. Specifically, more perceived support from parents, teachers, and close friends was associated with lower teacher-reported aggressive behavior, whereas classmate support buffered the impact of violence on peer-reported aggressive behavior. These findings, multiple reporter differences, and implications for preventive interventions are discussed. © 2008 Wiley Periodicals, Inc.
The spectrum of pediatric fibroblastic and myofibroblastic tumors.

Fibroblastic and myofibroblastic tumors in neonates, infants, and children provide a diagnostic dilemma in surgical pathology due to their relative rarity and similarity in appearances. These tumors may be congenital or occur early during the first years of life or later during the first and second decades of life. The morphologic, immunocytochemical, ultrastructural, cytogenetic, and molecular features of the more “common” pediatric fibroblastic and myofibroblastic tumors are reviewed. In addition, the importance of a multimodal approach to tumor diagnosis is emphasized, with correlation with treatment and outcome differences among these unique fibroblastic and myofibroblastic tumors. The importance of providing an accurate diagnosis with pediatric fibroblastic and myofibroblastic tumors cannot be overstated, because treatment, prognosis, follow-up, and outcome are based on the initial assessment of these fascinating, but oftentimes, perplexing tumors.
The diplomatic career of Mircea Eliade: A response to Adriana Berger

Adriana Berger has attacked Mircea Eliade's connection with the Romanian right-wing movement, the Iron Guard, or Legion of the Archangel Michael. Her article ‘Fascism and religion in Romania’, makes much of certain British Foreign Office documents which I have inspected in detail. Not only do these documents fail to corroborate Berger's conclusions but they cast real doubt on Berger's critical detachment. Her claim that Eliade was detained in England because of his political activities on behalf of the Iron Guard, and also of Nazi Germany, is without foundation. Other insinuations which she has made about Eliade's political motivations are subject to alternative interpretations. Eliade undoubtedly was vehemently nationalist in his youth and gave some support to the Legion of the Archangel Michael. However, we must constantly guard against permitting our pre-existent judgements of nationalism and fascism to dictate our reading of historical event. Even if justified, prejudice is still prejudice and is not ...
MASS AND SHADING EFFECTS ON MASCULINE-FEMININE JUDGMENTS ON THE RORSCHACH.

Summary College students were used to test the hypotheses that judgment of an achromatic Rorschach Inkblot as ‘masculine’ is a function of largeness of mass, and darkness of shading, and judgment of one as ‘feminine’ is a function of smallness of mass and lightness of shading. It was also predicted that the sex of the judge does not influence these judgments. The standard inkblots and mass and shading control blots were used with the semantic differential and a masculine-feminine sort technique. The results generally supported the hypotheses tested with the ‘shading hypotheses’ receiving the strongest support. The results were related, with reservation, to the “father” and “mother” hypotheses of cards IV and VII.
Role of androgens in the growth of endometrial carcinoma: An in vivo animal model

OBJECTIVE: We sought to create an animal model for the development of endometrial cancer in women with androgen excess. We examined the effects of estradiol and androgen, both alone and as precursors to estrogen biosynthesis on human endometrial cancers transplanted into a nude mouse model. STUDY DESIGN: We transplanted an estrogen-responsive, well-differentiated, established human endometrial carcinoma, EnCa-101, subcutaneously into athymic male nude mice. We established, first, that aromatase was expressed in this cell line, inducible by estrogen. We measured the growth of the tumor in the various groups weekly with Vernier calipers. We examined the effects of estradiol and androgens, both aromatizable and nonaromatizable, on tumor growth. RESULTS: Estrogen-supplemented tumors showed the greatest rate of growth and were significantly greater than the growth rate in castrate mice. Androgen-supplemented tumors showed a growth rate similar to that of tumors without significant hormonal exposure (castrate mice). Dihydrotestosterone had no effect on tumor growth in comparison with an agonadal state. CONCLUSIONS: Aromatizable and nonaromatizable androgens have little growth-promoting effect on a well-differentiated endometrial carcinoma. Estradiol is the most potent growth stimulus in our model.
Do sitting-atop metalloporphyrin complexes exist? Observation of N-H- - -π bonding in arene solvates of a diprotonated porphyrin dication

The existence of sitting-atop metalloporphyrin complexes, the proposed intermediates in the metalation of free-base porphyrins, has been explored via the microscopic reverse reaction, i.e., protonation of metalloporphyrins with a strong acid. The reaction of M(Tp-TP) (M = Zn, Cu, Ni; Tp-TP = dianion of tetra-p-tolylporphyrin) with mesitylenium carborane salts produced only the demetalated porphyrin in its diprotonated form, [H4Tp-TP][carborane]2 (carborane = CHB11H5Cl6-, CHB11H5Br6-, CHB11Cl11-). In arene solvents, the H4Tp-TP2+ dication shows an unusually upfield shifted 1H NMR resonance at ca. -6 ppm, which X-ray crystallography reveals to arise from N-H- - -pi hydrogen bonding of the acidic protons to arene solvent molecules.
The Culture of the Classroom: Socialization in An Urban Bilingual Classroom

This article reports on an ethnographic study of a fourth-grade bilingual classroom. The focus of the article is on the culture that is created in this classroom and how children are socialized to it. Three themes are explored: socialization around being engaged learners, socialization to participate in a community of learners, and socialization to be second-language learners. I argue that the culture of the classroom for students who typically do poorly in school and who have negative experiences in school, such as the poor, urban Latino students in this study, must be one that has different roles, values, beliefs, and expectations than what exists in the cultures outside the classroom. In this way, the children experience school in positive ways which can lead to school success.
Anion chelation by amido acid functionalized fused quartz/water interfaces studied by nonlinear optics.

We report resonantly enhanced surface second harmonic generation (SHG) measurements to track the interaction of the EPA priority toxic metal pollutant chromium(VI) with fused quartz/water interfaces containing tailor-made amino acids that serve as model systems for environmental and biological interfaces. χ(3) measurements of amido acid functionalized fused quartz/water interfaces are consistent with two acid−base equilibria, suggesting the formation of a laterally hydrogen-bonded environment similar to what is observed for aliphatic carboxylic acids. Chromate adsorption isotherms recorded at pH 7 are suggestive of an intramolecular chelation mechanism that becomes important when four or more hydrogen-bonding moieties are displayed toward the incoming chromate. The strong binding affinities of the amido acid functionalized fused quartz/water interfaces toward chromate are consistent with nearly 50% slower transport rates with respect to free-flowing groundwater, indicating that, in the absence of redox pr...
Insulin and Interleukin-4 Induce Desensitization to the Mitogenic Effects of Insulin-like Growth Factor-I PIVOTAL ROLE FOR INSULIN RECEPTOR SUBSTRATE-2

Abstract Insulin-induced desensitization to insulin-like growth factor-I (IGF-I) stimulated mitogenesis in bovine fibroblasts involves steps distal to IGF-I binding to its tyrosine kinase receptor. When quiescent cultures of bovine fibroblasts were stimulated with 10 nm IGF-I and total cell lysates immunoblotted with anti-phosphotyrosine antibody, we observed a band at ∼97 kDa, representing the β-subunit of the IGF-I receptor, and a predominant tyrosyl-phosphorylated species migrating as a broad band between 170 and 190 kDa. The majority of proteins in this latter band were immunoprecipitated by antibodies against insulin receptor substrate (IRS)-2 and not by antibodies against IRS-1. Pretreatment of bovine fibroblasts with 10 nm insulin for 48 h blocked subsequent IGF-I-stimulated DNA synthesis and the IGF-I-induced increase in tyrosyl-phosphorylated IRS-2. Insulin pretreatment did not alter IRS-1 or IRS-2 expression by these cells, as assessed by metabolic labeling and direct immunoblotting with IRS antibodies. The interleukin-4 (IL-4) cytokine receptor also has IRS-2 as its major substrate for tyrosine phosphorylation. Although 10 nm IL-4 was as effective as 10 nm IGF-I in stimulating IRS-2 phosphorylation, 10 nm IL-4 did not have comparable mitogenic power in these cells. Nonetheless, pretreatment of bovine fibroblasts with IL-4 inhibited IGF-I-stimulated DNA synthesis by 50–60%, concomitant with a decrease in IGF-I-induced IRS-2 phosphorylation. Insulin-induced desensitization could be prevented if a specific inhibitor of phosphatidylinositol 3-kinase (LY294002), but not an inhibitor of mitogen-activated protein kinase (PD98059), was present during the preincubation period. LY294002 also prevented the shift in IRS-2 molecular mass in response to prolonged incubation of cells with insulin. These data indicate that, in a nontransformed cell system, IRS-2 plays a key role in cellular desensitization to IGF-I-stimulated mitogenesis most likely through a feedback mechanism in the phosphatidylinositol 3-kinase pathway. Furthermore, they suggest that signaling through IRS-2 may provide an important point of integration for hormone, growth factor, and cytokine receptor systems that regulate critical cellular growth responses.
Deformation and fracture of adhesive layers constrained by plastically-deforming adherends

The use of an embedded-process zone (EPZ) model to investigate the mode I cohesive parameters for plastically-deforming, adhesively-bonded joints is demonstrated in this paper. It is shown that for the particular systems investigated, the cohesive parameters are consistent with an adhesive layer deforming in accordance with its bulk constitutive properties (as constrained by the adherends). In other words, these systems provide examples where the cohesive tractions exerted by an adhesive layer can be calculated simply from considerations of the constrained deformation of the adhesive. Consistent with such calculations, the peak stress in the adhesive layer decreases as the level of the constraint decreases (either with an increase in the thickness of the adhesive layer or with a decrease in the thickness of the adherends). It is also shown that owing to a compensating effect in which the critical displacement for failure varies with the constraint, the energy absorbed by the adhesive layer (the 'intrinsic...
Design and power management of a solar‐powered “Cool Robot” for polar instrument networks

The Cool Robot is a four-wheel-drive, solar-powered, autonomous robot designed to support summertime science campaigns in Antarctica and Greenland over distances exceeding 500 km. This paper provides an overview of key features of the robot, including design for good mobility, high efficiency, and long-term deployment under solar power in harsh polar environments. The Cool Robot's solar panel box, comprising panels on four sides and a top panel, encounters insolation variations with a bandwidth of up to 1 Hz due to sastrugi. The paper details a unique photovoltaic control algorithm to accommodate these variations. We deployed the robot at Summit Camp, Greenland to validate its mobility and power budget and to assess the photovoltaic control system. The 61 kg robot drove continuously at 0.78 m/s on soft snow, its 160 W average power demand met by solar power alone under clear skies above 16° sun elevation. The power-control system reliably matched input with demand as insolation varied during testing. A simple GPS waypoint-following algorithm provides low-bandwidth path planning and course correction and demonstrated reliable autonomous navigation during testing over periods of 5–8 h. Field data validate the Cool Robot design models and indicate that it will exceed its design goal of carrying a 15 kg payload 500 km across Antarctica in 2 weeks. A brief description of instrument payloads and scientific studies aided by networks of such autonomous solar robots is provided. © 2007 Wiley Periodicals, Inc.
Going with the Flow: Can Christian Faith Communities in the UK Flourish in Non-Institutional Civil Society?

AbstractThe aim of this article is to reflect theologically on recent research into the changing nature of civil society with a view to exploring the implications of these changes for the way churches and other faith communities might contribute to civil society in the future. The article looks at the mismatch between government rhetoric concerning the role of churches and faith communities in building up civil society, and the actual experience of faith communities becoming engaged in formal civil society activities such as regeneration and social cohesion which has often felt disempowering and awkward. The article then looks at the growth of non-institutional society (i.e. broad-based organizations and direct action campaigns) which tends to lie outside government control and raises the theological and strategic question as to whether more liquid and flexible forms of political participation have something to offer churches seeking to become more appropriately engaged in postmodern flows of society and ...
Forming transmembrane channels using end-functionalized nanotubes

Using dissipative particle dynamics (DPD) simulations, we examine the interaction between amphiphilic nanotubes and lipid bilayer membranes. The nanotubes are represented by a hydrophobic shaft that is end-functionalized with hydrophilic groups. Nanotubes that are capped by a monolayer of hydrophilic beads or also encompass hydrophilic “hairs” on just one end of the shaft are found to spontaneously penetrate and assume a transmembrane position; the process, however, depends critically on the membrane tension. On the other hand, nanotubes that include hydrophilic hairs at both ends of the hydrophobic shaft are not observed to spontaneously self-organize into the bilayer. When the membrane is stretched to form a pore, the nanotubes with two hairy ends adsorb on the edge of the pore and become localized in the membrane, thus forming a transmembrane channel. The findings from these studies provide guidelines for creating biomimetic nanotube channels that are capable of selectively transporting molecules through the membrane in response to changes in the local environment.
Positive country images, trust and public support for European integration

In this paper I contribute to the scholarship on public support for European integration by arguing that member-states’ positive images influence individuals’ support decisions. An attribute of this positive image is trust, which individuals utilize given the complexity of the integration process, the salient impact it has on their lives and the low levels of information individuals possess. The use of a member-state's image is therefore a short-cut to evaluate integration's impact on individuals. As the development of integration is strongly influenced by the relatively more economically powerful member-state, trust in Germany increases the level of support, more so than trusting the remaining members.
Diffusion of sediment on the lee of dune‐like bedforms: theoretical and numerical analysis

Theoretical and empirical analyses of flow structure, sediment transport, and sediment size characteristics at the crest of dune-like bedforms indicate that it is possible to describe, at least semi-quantitatively, the diffusion and deposition of sediment on the leeside of such structures. A numerical program based on this analysis simulates the grain-size distribution and deposition rate on the leeside of dunes for specified flow conditions and bed material. Evaluation of flow and sediment variables through the numerical simulation program shows that flow velocity, flow depth and sediment size have a strong influence on the deposition rate and texture of leeside sediment before avalanching. Sorting of the bed material, in particular, appears to exert a strong control on both the grain-size and the deposition-rate gradients.
The heart in hypothyroidism.

Abstract An attempt has been made to review, from the large body of pertinent data, certain aspects of cardiovascular structure and function in hypothyroidism. Although significant alterations have been defined, the preponderance of the data indicates that myocardial decompensation is only rarely, if ever, a consequence of hypothyroidism. Furthermore, the widely assumed causative role of the hypothyroid state per se in the pathogenesis of atherosclerosis is questioned and the need for a critical re-evaluation defined, particularly in the less severe cases and in patients without attendant complicating factors such as age, hypertension, diabetes, etc. The important role of pericardial effusion in the genesis of certain signs and symptoms is underlined. The meagerness of data relating to significant biochemical effects of hypothyroidism at a cellular or subcellular level is noted. The lack of significant effects of hypothyroidism on the related pulmonary and renal functions is delineated. The induction of hypothyroidism for the therapy of severe angina pectoris or congestive heart failure is reviewed ; the need is underscored for further study of (1) the mechanism of action of lowered thyroid function on these cardiac conditions, (2) the abnormalities of thyroid hormone binding, tissue uptake and turnover in certain euthyroid patients with supraventricular tachycardias, and (3) the therapy of this condition by antithyroid measures.
Network capacity of UWB-based sensor networks

Ultra-wideband (UWB) has great potential for wireless communications in emerging applications such as sensor networks. This paper studies the following fundamental problems for UWB-based sensor networks: For a given network instance, what is the maximum data rate (network capacity) that can be received at the base-station (i.e., sink node)? What is the network capacity bound among arbitrary network instances? We show that these problems can be cast into a cross-layer formulation with joint consideration of routing, scheduling, power control, and rate assignment. For a given network instance, we find a closed-form network capacity as well as corresponding optimal routing, scheduling, power control, and rate assignment. We also find a network capacity bound among arbitrary network instances.
SUPERIORITY OF CORONARY SINUS CARDIAC BIOMARKER SAMPLING OVER PERIPHERAL VENOUS BLOOD FOR PROGNOSTICATION IN CARDIAC RESYNCHRONIZATION THERAPY: THE BIOCRT STUDY

Coronary sinus (CS) blood is obtainable during implantation of cardiac resynchronization therapy (CRT). We aimed to determine whether CS or peripheral venous (PV) biomarkers are predictive of CRT response and major adverse cardiovascular events (MACE) using single and multi-marker strategies. In 73
Lamina Cribrosa Depth in Different Stages of Glaucoma

PURPOSE To compare lamina cribrosa (LC) depth between normal eyes and eyes with different stages of treated glaucoma. METHODS Serial enhanced depth imaging (EDI) optical coherence tomography (OCT) B-scans of the optic nerve head were obtained. To generate the mean LC depth for each eye, LC depths were measured in 11 equally spaced horizontal B-scans and averaged. The mean LC depth was compared among normal, preperimetric, mild-to-moderate, and severe glaucoma groups. Among patients with visual field (VF) loss, correlation analysis was performed (1) between mean LC depth and VF mean deviation (MD), and (2) between mean LC depth and retinal nerve fiber layer (RNFL) thickness. RESULTS Eighty-six normal eyes (age, 56 ± 14 years), 47 preperimetric glaucoma eyes (age, 60 ± 16 years), 55 mild-to-moderate glaucoma eyes (age, 59 ± 16 years; VF MD, -6.0 ± 3.2 dB), and 60 severe glaucoma eyes (age, 59 ± 17 years; VF MD, -19.7 ± 6.1 dB) were included. Mean LC depth was significantly greater in preperimetric glaucoma than in normal eyes (390 vs. 344 μm, P = 0.004) and in mild-to-moderate than in preperimetric glaucoma eyes (448 vs. 390 μm, P = 0.001). However, no significant difference was observed between mild-to-moderate and severe glaucoma eyes (448 vs. 437 μm, P = 0.52). No correlation was observed between LC depth and VF MD (P = 0.56) or RNFL thickness (P = 0.90) in glaucomatous eyes with VF loss. CONCLUSIONS In treated glaucoma, posterior LC displacement occurs mostly in the preperimetric and mild-to-moderate glaucoma stages. This warrants further investigation of LC depth as a parameter to monitor glaucoma progression in the early stages.