cssi/SciSciGPT-SciSciNet huggingface dataset:
8-Chloro-cAMP Serves as a Prodrug for the RNA Directed Nucleoside Analog, 8-Chloro-Adenosine

Previous preclinical and clinical work with 8chloro-cAMP (8-Cl-cAMP) has raised questions whether it works as a cAMP analog or as a nucleoside analog, 8-Cl-Adenosine (Ado). Although degradation of 8-Cl-cAMP to 8-ClAdo in culture medium or plasma has been shown, cellular pharmacology is missing. Additionally, conversion of 8-Cl-Ado to 8-ClcAMP in the cell and its effects via a Protein Kinase A (PKA) dependent pathway is possible. However, there was no measurable increase in PKA activity by 8-Cl-Ado. The phorbol ester PMA, which blocks both glucocorticoid and cAMP mediated cell death, was not able to block 8-Cl-Ado mediated apoptosis. These data suggested that the mechanism of action of 8-Cl-Ado is via a separate pathway than either glucocorticoid or PKA signaling. In multiple myeloma (MM) and leukemia cells, both 8-Cl-cAMP and 8-Cl-Ado incubation resulted in the accumulation of 8Cl-Ado mono-, di-, and tri-phosphate (8-ClATP). Accumulation of 8-Cl-ATP was dependent on both the exogenous concentration of 8-Cl-Ado and incubation time. At the 10 μM level of 8-Cl-Ado, more than 400 pM 8-ClATP accumulated in MM cells after 12 hours. Similar incubation with 8-Cl-cAMP also resulted in accumulation of 8-Cl-ATP, albeit at a lower level. The formation of 8-Cl-ATP from 8-Cl-cAMP was inhibited by more that 80% in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine in the medium, suggesting extracellular conversion of 8-Cl-cAMP to 8-Cl-Ado. Parallel to accumulation of 8-Cl-ATP, there was a decline in the endogenous level of cellular ATP pool. This was associated with inhibition of RNA synthesis but did not affect DNA synthesis. Among the RNA species, there was maximum inhibition of mRNA, which was consistent with highest incorporation of 8-Cl-Ado resi­dues. Taken together, these data demonstrate that 8-Cl-cAMP serves as a prodrug for 8-Cl­Ado. Because 8-Cl-Ado induces apoptosis in MM and leukemia cells resistant to traditio­nal chemotherapeutic drugs, this analog may be a potential new agent for these diseases.
A Mentorship Program for Academic Obstetrician Gynecologists that Improved Publication and Overall Confidence for Success.

This article aims to evaluate the impact of a mentorship program to enhance the training of clinical and research scientists in obstetrics and gynecology (OBGYN). A departmental course was developed for junior faculty and fellows based on their areas of interest. The research was IRB-approved. The curriculum consisted of monthly interactive workshops for an interdisciplinary group of trainees in OBGYN. Themes included research, education, and leadership in academic OBGYN. There was a strong emphasis on participatory exercises. Examples of curriculum topics included manuscript publication and review, grant writing, working with an IRB, promotion, and time management. Pre- and post-course questionnaires assessed participants' confidence in skills related to the course topics. Generalized linear models were used to assess changes in post-course response, using each question as the dependent variable and an indicator for post-course as the predictor variable. The control group was composed of junior faculty and fellows before the course was initiated. Outcome measures included the number and impact factor of published manuscripts. A Wilcoxon rank-sum test was used to assess outcome measures. Of the 118 attendees, 26 (22.0%) were junior faculty, 35 (29.66%) were clinical fellows, and 28 (23.7%) were research fellows, other research staff, or students. For each 3-year course series, an average of 20 participants completed the post-course surveys, of which 72% were clinical fellows, 22% were assistant professors, and 5% were instructors. The data revealed a statistically significant change in the participant's overall confidence in skills related to research, education, and leadership when comparing the cumulative results from the pre-to-post course surveys (p < 0.001). Specifically, participants noted improved confidence in their skills related to clinical and translation research (p < 0.001) and leadership and academic career advancement (p = 0.001). Additionally, junior faculty and clinical fellows who attended the course had a higher number of publications during the course period compared with controls (p = 0.003 and p = 0.008, respectively). This subspecialty-tailored, departmental training program was effective in increasing junior faculty and clinical fellows' confidence in skills related to career advancement and research and in the number of peer-reviewed publications.
A Continuum of Pedagogies for Preparing Teachers to Use High-Leverage Practices:

This article provides a framework and description of pedagogies that may be used in teacher preparation across a range of settings from college classrooms to P-12 settings to support teacher candid...
Measles immunity in the China-Myanmar border region, Lincang city, Yunnan province, 2017

A recent measles importation-related outbreak in the China-Myanmar border region required outbreak response immunization to stop the outbreak, raising the question of measles immunity in the area. ...
Cyclic di-GMP in Burkholderia spp.

Burkholderia spp. survive in diverse ecological niches in association with soil, plants, and animals. In these environments, some members of the Burkholderia spp. participate in beneficial interactions that promote plant growth, nutrient cycling, and bioremediation; however, some Burkholderia spp. are also pathogens of plants, fungi, amoebae, insects, animals, and humans. In order to transition between niches and compete with other microbes, Burkholderia spp. have evolved sophisticated sensory systems to detect and respond to a variety of cues and signals from external stimuli that allow rapid response to changing environmental conditions. Cyclic di-GMP is a nearly universal bacterial second messenger and a key signaling molecule in Burkholderia spp. that regulates a variety of bacterial behaviors including virulence, motility, and biofilm formation. This chapter will review the progress toward understanding the sensory components and associated regulatory components that respond to environmental cues and correspondingly alter the intracellular levels of cyclic di-GMP. Recent reports indicate that various members of the Burkholderia spp. respond to alterations in temperature, nutrient availability, and population density (via Burkholderia diffusible signal factor) to control bacterial behaviors associated with pathogenesis, dissemination, and survival in the niches that Burkholderia spp. inhabit.
Mammary stem cells and their niche during aging

Abstract The mammary gland is unique in that its development is primarily completed during puberty making the postnatal mammary stem cells responsible for both development and homeostasis, as well as reproductive functions in the adult mammal. In order to respond to these demands, an association between the mammary stem cells and their microenvironment within the breast tissue, referred to as the stem cell niche, is thought to occur in a dynamic and highly regulated state. Hormone, paracrine, autocrine, and mechanosensation are all factors governing the physiology of the mammary gland. Aging on the other hand, is known to cause a decline in the function of tissues and its effect on the mammary gland is also remarkable. How aging effects the mammary stem cells and their niche will be discussed in several topics including quiescence, senescence, and gene expression in potential mammary stem cells, their affiliated epithelial populations, stroma, and other elements of the mammary stem cell niche.
Gerotranscendence and Alaska Native Successful Aging in the Aleutian Pribilof Islands, Alaska.

The population of the United States is aging and by 2045 it is projected that approximately 1 in every 6 Alaskans will be 65+. Delivering healthcare and meeting the needs of older Alaskans in their community is critical to supporting healthy aging and community sustainability. Alaska Native (AN) Elders are underserved with very few studies providing an emic perspective on their experience aging. This research opens the door and allows us a glimpse of the AN Elder experience of aging: the values, beliefs, and behaviors that allow them to age well. This study highlights the characteristics and activities of AN Elders in the Aleutian and Pribilof Islands to further develop the model of AN successful aging. There are many theories of aging and this study explores a cross-cultural understanding of gerotranscendence - the personal and interpersonal changes that result from successful aging or achieving Eldership. This study interviewed Elders in two communities of the Aleutian and Pribilof Islands region. Using 22 standardized questions based on the explanatory model, researchers facilitated discussion of what it means to be an Elder and age successfully. Employing thematic analysis, interview transcripts were analyzed for themes to organize the data. Themes were organized into 5 core elements of successful aging with specific emphasis on values, beliefs, and behaviors that were protective and helped them adapt to aging-related changes. Interview content, meaning, and themes support the four elements of the AN model of successful aging developed by Lewis (The Gerontologist, 51(4), 540-549, 2011): Mental and Emotional Wellbeing, Spirituality, Purposefulness and Engagement, and Physical Health. Elders’ stories highlight the importance of reflection, personal growth, and psychosocial development. Elders who more strongly identified with their role in the community described how their perspective had changed and they shared stories that emphasized culture, connection to the land, and enjoyment of daily activities that resulted in increased life satisfaction. Elders provided clear evidence that they experienced aspects of gerotranscendence, which Tornstam (Journal of Aging Studies, 11(2), 143-154, 1997) categorized as the cosmic dimension, the self, and social and personal relationships. Elders adapting to aging-related changes and embracing their role as an Elder provided the greatest evidence of gerotranscendence - they developed new perspectives on life, took on new roles within the community, and experienced a shift in mindset that reinforced the importance of culture, tradition, and the Native Way of Life. This research allowed AN Elders to share their experiences, define successful aging, and expand the concept of Eldership to include changes in mindset, values, and relationships with themselves and others. The study is a framework to help us better understand the experiences of AN Elders aging successfully and the wisdom they wish to impart to others to help them learn to live healthy and meaningful lives.
Pulse Arrival Time Is Associated With Hemorrhagic Volume in a Porcine Model: A Pilot Study.

BACKGROUND Hemorrhage is a major cause of preventable death worldwide, and early identification can be lifesaving. Pulse wave contour analysis has previously been used to infer hemodynamic variables in a variety of settings. We hypothesized that pulse arrival time (PAT), a form of pulse wave contour analysis which is assessed via electrocardiography (ECG) and photoplethysmography (PPG), is associated with hemorrhage volume. METHODS Yorkshire-Cross swine were randomized to hemorrhage (30 mL/kg over 20 minutes) vs. control. Continuous ECG and PPG waveforms were recorded with a novel monitoring device, and algorithms were developed to calculate PAT and PAT variability throughout the respiratory cycle, termed "PAT index" or "PAT_I." Mixed effects models were used to determine associations between blood loss and PAT and between blood loss and PAT_I to account for clustering within subjects and investigate inter-subject variability in these relationships. RESULTS PAT and PAT_I data were determined for ∼150 distinct intervals from five subjects. PAT and PAT_I were strongly associated with blood loss. Mixed effects modeling with PAT alone was substantially better than PAT_I alone (R2 0.93 vs. 0.57 and Akaike information criterion (AIC) 421.1 vs. 475.5, respectively). Modeling blood loss with PAT and PAT_I together resulted in slightly improved fit compared to PAT alone (R2 0.96, AIC 419.1). Mixed effects models demonstrated significant inter-subject variability in the relationships between blood loss and PAT. CONCLUSIONS Findings from this pilot study suggest that PAT and PAT_I may be used to detect blood loss. Because of the simple design of a single-lead ECG and PPG, the technology could be packaged into a very small form factor device for use in austere or resource-constrained environments. Significant inter-subject variability in the relationship between blood loss and PAT highlights the importance of individualized hemodynamic monitoring.
Where Does QKD Fit in a Post-quantum Secure World?

Quantum Key Distribution or QKD is the much-heralded first fruit of the upcoming quantum revolution, which promises more accurate timing, more secure communications, more sensitive imaging and sensing, and of course more power computing. QKD has the potential to offer ultra-secure communications, but there are several other, more cost-effective options. The talk will assess the landscape pragmatically, presenting recent customer trials of both QKD and post-quantum crypto solutions. The major QKD use cases being explored in the AIRQKD collaborative project will be described and innovative Physically Unclonable Function (PUF) technology will be applied where relevant to supplement QKD in access environments.
Effects of novel brain‐penetrating oxime acetylcholinesterase reactivators on sarin surrogate‐induced changes in rat brain gene expression

Past assassinations and terrorist attacks demonstrate the need for a more effective antidote against nerve agents and other organophosphates (OP) that cause brain damage through inhibition of acetylcholinesterase (AChE). Our lab has invented a platform of phenoxyalkyl pyridinium oximes (US patent 9,277,937) that demonstrate the ability to cross the blood-brain barrier in in vivo rat tests with a sarin surrogate nitrophenyl isopropyl methylphosphonate (NIMP) and provide evidence of brain penetration by reducing cessation time of seizure-like behaviors, accumulation of glial fibrillary acidic protein (GFAP), and hippocampal neuropathology, as opposed to the currently approved oxime, 2-pyridine aldoxime methyl chloride (2-PAM). Using two of the novel oximes (Oximes 1 and 20), this project examined whether gene expression changes might help explain this protection. Expression changes in the piriform cortex were examined using polymerase chain reaction arrays for inflammatory cytokines and receptors. The hippocampus was examined via quantitative polymerase chain reaction for the expression of immediate-early genes involved in brain repair (Bdnf), increasing neurotoxicity (Fos), and apoptosis control (Jdp2, Bcl2l1, Bcl2l11). In the piriform cortex, NIMP significantly stimulated expression for the macrophage inflammatory proteins CCL4, IL-1A, and IL-1B. Oxime 20 by itself elicited the most changes. When it was given therapeutically post-NIMP, the largest change occurred: a 310-fold repression of the inflammatory cytokine, CCL12. In the hippocampus, NIMP increased the expression of the neurotoxicity marker Fos and decreased the expression of neuroprotective Bdnf and antiapoptotic Bcl2l1. Compared with 2-PAM, Oxime 20 stimulated Bcl2l1 expression more and returned expression closer to the vehicle control values.
Revenue and Distributional Effects of the Individual Income and Estate Tax Provisions of Senator Thompson's Plan for Tax Relief and Economic Growth

Republican Presidential Candidate Fred Thompson has announced a tax plan that combines tax cut extensions, additional tax cuts, and an election to pay tax under a new alternative tax system that would substitute a larger standard deduction for all current deductions and credits and have two rates of 10 and 25 percent. Thompson's plan would reduce federal revenues by $6-7 trillion over ten years, amounting to a reduction of almost 20 percent below current projections, and would be highly regressive. This article describes the proposed changes in the individual income and estate tax and examines their implications for revenue and the distribution of tax burdens.
Synthesis of a Glycosylphosphatidylinositol (GPI) fragment as a potential substrate for mannoprotein transglycosidases

A glycophosphatidylinositol tetrasaccharide fragment was synthesized to mimic the core features of primary model, that of Saccharomyces cerevisiae. The salient feature of this approach is centered on the quick access to various α-1,2- and α-1,6-mannosyl and α-1,4-glycosyl linkages by using simple glycosylation and protective-group techniques. 1D and 2D-J-resolved NMR spectroscopy was used to verify the α-configuration of the new linkages. The tetrasaccharides obtained in this work are useful for examining fungal cell-wall glycoprotein cross-linking by transglycosidase enzymes for antifungal drug development.
A backpropagation filtering algorithm for cone beam tomography

A backprojection filtering algorithm is presented for cone beam tomography with circle-and-line orbit. The algorithm first converts the 2-D cone beam projections into plane integrals, which are approximated by the line integrals on the 2-D cone beam detector plane. The plane integrals are rebinned into the Radon space. The multiply measured data are properly normalized by a weighting function in the Radon domain. The frequency-domain Radon inversion formula is used to reconstruct the image. This algorithm corrects the major drawback of a previous algorithm which discarded the multiply sampled data. This algorithm uses all the untruncated plane integrals. In addition, it is flexible and can be easily tailored to any orbit. >
A Burden Too Heavy: Berghuis v. Smith and the Fading Right to a Jury From a Fair Cross-Section of the Community

In November of 1993, Diapolis Smith was convicted of second degree murder by an all-white jury in Kent County, Michigan. On appeal, Smith challenged the constitutionality of Kent County’s jury-selection procedure, claiming he had not been afforded his Sixth Amendment right to a jury drawn from a fair cross-section of the community. This Comment examines Smith’s claim and argues that the Supreme Court ultimately erred in ruling that Smith failed to make a prima facie case for a Sixth Amendment claim. First, this Comment argues that Smith presented sufficient evidence for the Court to draw a reasonable inference, under Duren v. Missouri, that Kent County’s jury-selection procedures systematically excluded African Americans. Second, in the face of extensive academic research that demonstrates the nexus between socioeconomic disparity and minority underrepresentation on juries, this Comment argues that the Supreme Court should be more amenable to claims that hinge on the presence of socioeconomic factors. Finally, this Comment addresses the consequences of the Berghuis v. Smith decision and the solutions to minority underrepresentation in jury venires.
Arrayed liquid rotor electret power generator systems

We report our work on liquid rotor electret power generators (LEPG). LEPG devices are essentially fixed-charged, Teflon-electret capacitors with air-filled gaps and liquid droplets that move by vibration. As the liquid moves into and out of the gaps, a net voltage is generated across the capacitor as image charges on the electrodes redistribute according to the position of the droplets. In this work, we also study serial and parallel arrays of LEPG power generators to increase power output. Power output from parallel arrays scales linearly with number of devices, as expected, to produce power output up to about 10 /spl mu/W. Our initial results show that series arrays need to be studied more because they involve more complicated impedance matching issues.
Using Google Data to Predict Who Will Vote

This paper argues that Google searches prior to an election can be used to predict turnout in different parts of the United States. For the 2008 and 2010 election, October search rates for "vote/voting," compared to four years earlier, explained 20-40 percent of state-level change in turnout rates. Out-of-sample predictions made prior to the 2012 election were strong. The data might prove useful in predicting candidate performance in midterm elections. If turnout is predicted to be high, the Democratic candidate can be expected to do better than the polls suggest. For presidential elections, the data can be useful in estimating the composition of the electorate, by comparing media market search rates to media market demographics. In the 2008 election, the Google data would have correctly predicted substantially increased African-American turnout. The out-of-sample 2012 demographics predictions using Google data were largely correct. It correctly forecast elevated Mormon turnout. It correctly forecast, contrary to some pollsters’ predictions, that African-American, Hispanic, and youth turnout rates would remain at 2008, rather than 2004, levels.
An image-based computational method for characterizing whole-cell scale spatiotemporal dynamics of intracellular transport

Intracellular transport is the process of distributing and collecting materials, often packaged in different forms of cargoes, to fulfill changing structural and functional needs within the cell. Although the molecular machinery for intracellular transport has largely been identified, how this process is regulated globally in space and time remains unclear. In a step towards answering this question, we developed an image-based computational method for characterizing spatiotemporal dynamics of intracellular transport at the whole-cell scale to separate signals of moving and stationary cargoes. Specifically, we extended an algorithm that we developed previously for removing background fluorescence of static images. This separation allows us to extract from time-lapse images the global pattern of cargo movement without single particle tracking of individual cargoes. Based on this separation, we characterized the spatiotemporal dynamics of intracellular transport in terms of the spatial localization of stationary cargoes and the spatiotemporal patterns of cargo movement, respectively. We first tested and validated our methods using synthetic images. We then used our methods to analyze time-lapse images of Lamp1 transport and found different global patterns of transport behavior.
Little's law flow analysis of observation unit impact and sizing.

Expanding hospital capacity by developing an observation unit may be an important strategy in congested hospitals. Understanding the principles for evaluating the potential impact and appropriate sizing of an observation unit is important. The objective of this paper is to contrast two approaches to determining observation unit sizing and profitability, real options, and a flow analysis based on Little’s Law. Both methods have validity and use similar data sets. The Little’s Law approach has the advantage of providing an estimate of appropriate size for the unit and a natural internal consistency check on data. The benefits of an observation unit can depend critically on assumptions regarding backfill patients, and minor changes in data or assumptions can translate into significant changes in annual financial consequences. Using both the real options and the Little’s Law approaches provides some internal consistency checks on data and assumptions. Both are sufficiently simple to be easily mastered and conducted. Using these two simple and accessible methods in parallel for computing the size and financial consequences for an observation unit is recommended. ACADEMIC EMERGENCY MEDICINE 2011; 18:183–189 a 2011 by the Society for Academic Emergency Medicine
Reliability studies of photovoltaic module insulation systems

Three major PV (photovoltaic) module reliability issues are reviewed: (1) susceptibility to voltage breakdown, (2) hermeticity/water ingress, and (3) moisture-induced corrosion. Based upon research findings, a simple production-line qualification test was developed that determines whether or not the electrical insulation system is consistent with safety, electrochemical corrosion, and PV system ground-fault sensing requirements under wet operating conditions. The test combines elements of an electrochemical corrosion test and a wet hi-pot test into a single, simple procedure for field, production-line, or laboratory use. >
A cross-continental look at the patterns of avian species diversity and composition across an urbanisation gradient

Context As humans become increasingly urban, the need for conservation of nature in cities increases and requires an understanding of the patterns and processes of urban ecosystems. In particular, because humans are the most dominant species in urban areas, understanding the role humans play in these ecosystems (direct and indirect) will be of primary importance. Aims We examine the diversity and composition of bird species across an urbanisation gradient in two cities (Berlin, Germany, and Seattle, Washington, USA). We determine the degrees of species urban tolerance and examine how certain biological traits of species, namely, diet, whether or not species use bird feeders, nest sites and innovation rate, characterise species urban tolerance. Finally, we determine whether human provisioning (bird feeders and nest boxes) influences what types of species persist across the urbanisation gradient. Methods We surveyed bird abundance and species richness using point counts and surveyed human provisioning by conducting door-to-door interviews of residents across an urbanisation gradient in Berlin and Seattle. Key results We found that patterns of species richness were similar in both cities, but that species composition in Berlin changed less across the urbanisation gradient than it did in Seattle. The majority of birds in Berlin were urban tolerant, whereas in Seattle, they were moderately urban tolerant and intolerant. A cluster analysis revealed that, in general, in Berlin, omnivorous, open-nesting birds that use bird feeders and have relatively high innovation rates tended to be urban tolerant. In Seattle, birds that were mostly omnivorous, nested in open cups, and used bird feeders tended to be moderately urban tolerant and they were influenced by provisioning of food by humans. Conclusion Urbanisation and human interactions with birds can act as ecological filters, favouring certain bird species that can lead to varying species compositions across an urban gradient. These differences in species composition across the gradient may be more noticeable in younger cities than in older cities where the filtering process has been occurring for longer time. Implications By providing a variety of habitats and supplementing natural foods and nesting places, urban planners and residents can help conserve bird diversity in urban areas.
Effects of pH and phosphate on CeO2 nanoparticle dissolution.

As the result of rapidly grown nanotechnology industries, release of engineered nanoparticles (ENPs) to environment has increased, posing in a serious risk to environmental and human health. To better understand the chemical fate of ENPs in aquatic environments, solubility of CeO2 NPs was investigated using batch dissolution experiments as a function of pH (1.65–12.5), [phosphate] and particle size (33 and 78 nm). It was found that CeO2 dissolution was only significant at pH < 5 and inversely proportional to surface area. After 120 h, the release of Ce was 3 times greater in large NPs than that in small NPs that is likely contributed by the difference in exchangeable Ce(III) impurity (small: 0.3 mM kg 1
Static Measure of Foot Loading

Static and dynamic loading of the foot are important characteristics for understanding human walking in both health and disease. The goal of this investigation was to determine whether an objective measure of normal midstance loading of the foot could reliably be recorded using readily available disposable qualitative recording devices. Ten randomly selected normal volunteers were trained to step on Harris mat and Pressure Stat recording devices during normal walking. Each of the recordings was divided into 5 weight-bearing regions by 2 separate examiners. After outlining each foot, the recordings were digitized and compared. Interobserver reliability ranged from 0.81 to 0.96 for the Harris mat technique and 0.94 to 0.97 for the Pressure Stat technique. Data from a linear regression plot indicate high precision of calculations of the foot masks between the 2 examiners based on an R(2) value of 0.966 using the Pressure Stat method. These data plus a linear regression plot suggest that both qualitative recording devices, when digitized using a standardized format, appear to obtain a reliable objective measure of midstance loading during normal gait. The Pressure Stat device may be slightly more reliable. It is planned to use this standardized experimental model to compare objectively patterns of midstance loading in patients with injury or disease that is capable of altering normal walking.
Structure of slope-critical configurations

In 1970, P. R. Scott conjectured, and recently P. Ungar proved, that n noncollinear points in the plane determine at least n−1 directions. The goal here is to obtain information on the structure of the critical sets where the minimum of n−1 is attained. Such a set is distributed in a rather regular way onto ‘spokes’ radiating out from a ‘centrex’ point. If the number of spoke-pairs is even, the set must be centrally symmetric. Moreover, some bounds on the number of points per spoke are obtained. These results lead to the characterization, for small n, of certain types of slope-critical configurations.
Public Policy Model of Delays in a Large Network of Major Airports

As more airports in the United States and in Europe become congested, it is increasingly common for delays at one or more airports to spread to other parts of the network. This paper describes an analytical model developed to study this complex phenomenon. The Approximate Network Delays (AND) model computes the delays from local congestion at individual airports and captures the "ripple effect" that leads to the propagation of these delays to other airports. AND can be used to explore at a macroscopic level the implications of a large number of policy alternatives and future scenarios on systemwide delays and associated costs. It has been fully implemented for a network consisting of the 34 busiest airports in the continental United States and for a network of the 19 busiest airports in Europe. An analysis is presented of the estimation of ground slack in the scheduled turnaround times and its strong relation with the spreading of delays. Furthermore, AND shows the effect of delay propagation in an airpor...
Focusing a beam of light with left-handed metamaterials

We present a theoretical study of a new metamaterial with a gradient negative index of refraction which can focus a collimated beam of light coming from a distant object. Using the Fermat principle for minimum time propagation of a light beam passing an optically inhomogeneous medium we derive a gradient of the negative index of refraction for a slab of the negative refractive metamaterial. A thin metal film pierced with equidistantly spaced circular holes having specific profile of their diameters was used to model a metamaterial with a gradient of the negative index of refraction. Based on the effective medium approximation for the real effective dielectric permittivity of the patterned metal film pierced with round or square holes, we design a profile of the structured film for a given focal length. FDTD calculations confirm the focusing of a plane electromagnetic wave passing through a system of equidistantly spaced holes in a metal slab with decreasing diameters towards the edges of the slab.
Visual direction depends on the operation of spatial constancy mechanisms: the oculobrachial illusion

Abstract Subjects fixating a target light attached to their stationary hand saw it move when illusory motion of their arm was induced by muscle vibration. During the experienced visual motion and change in visual direction of the target light, their eyes maintained steady fixation. The existence of an ‘oculobrachial ilusion’ provides evidence that visual direction depends on the operation of a spatial constancy mechanism interrelating sensory information about the external environment and the moment-to-moment postural configuration of the body.
Thiamine and Oxidants Interact to Modify Cellular Calcium Stores

Diminished thiamine (vitamin B1) dependent processes and oxidative stress accompany Alzheimer's disease (AD). Thiamine deficiency in animals leads to oxidative stress. These observations suggest that thiamin may act as an antioxidant. The current experiments first tested directly whether thiamin could act as an antioxidant, and then examined the physiological relevance of the antioxidant properties on oxidant sensitive, calcium dependent processes that are altered in AD. The first group of experiments examined whether thiamin could diminish reactive oxygen species (ROS) or reactive nitrogen species (RNS) produced by two very divergent paradigms. Dose response curves determined the concentrations of t-butyl-hydroperoxide (t-BHP) (ROS production) or 3-morpholinosydnonimine ((SIN-1) (RNS production) to induce oxidative stress within cells. Concentrations of thiamine that reduced the RNS in cells did not diminish the ROS. The second group of experiments tested whether thiamine alters oxidant sensitive aspects of calcium regulation including endoplasmic reticulum (ER) calcium stores and capacitative calcium entry (CCE). Thiamin diminished ER calcium considerably, but did not alter CCE. Thiamine did not alter the actions of ROS on ER calcium or CCE. On the other hand, thiamine diminished the effect of RNS on CCE. These data are consistent with thiamine diminishing the actions of the RNS, but not ROS, on physiological targets. Thus, both experimental approaches suggest that thiamine selectively alters RNS. Additional experiments are required to determine whether diminished thiamine availability promotes oxidative stress in AD or whether the oxidative stress in AD brain diminishes thiamine availability to thiamine dependent processes.
A characterization of a java-based commercial workload on a high-end enterprise server

While past studies with simple Java benchmarks like SPECjvm98 and SPECjbb2000 have been integral in advancing the industry, this paper illustrates some of the characteristics of a more complex and realistic 3-Tier J2EE (Java 2 Enterprise Edition) commercial workload, SPECjAppServer2004.In the course of this study, we both validate and disprove certain assumptions commonly made by researchers about Java workloads. For instance, on a tuned system having a heap of the appropriate size, the fraction of CPU time spent on garbage collection (GC) for this complex workload is small (
K(+)- and temperature-evoked taurine efflux from hypothalamic astrocytes.

Abstract Hypothalamic astrocytes in culture released taurine, a suspected inhibitory amino acid neurotransmitter/neuromodulator/osmoregulator, in response to isoosmotically increasing extracellular K + in a dose-dependent fashion. In the absence of added Ca 2+ , basal release levels rose to approach those obtained after exposure to 60 mM K + in the presence of 2.5 mM Ca 2+ , and were only partially lowered by the addition of 10 mM Mg 2+ . Stimulation with K + (60 mM) did not further increase taurine efflux above the high basal levels seen in the absence of Ca 2+ . Under standard conditions complete replacement of Na + with choline Cl had little effect on basal taurine release, but reduced K + -evoked (60 mM) efflux by 60%. The temperature dependence of the basal levels of taurine released from hypothalamic astrocytes was similar to that seen for cultured cerebellar astrocytes and neurons over the range 5–50°C. Taurine release increased from 5 to 15°C, remained constant between 15 and 33°C, decreased between 33 and 37°C and increased thereafter. The infection point of increased basal taurine release seen around 37°C (most prominent in astrocytes), may be of physiological significance. Results presented also show that the ion (Na + , Ca 2+ and K + ) sensitivities of taurine efflux for cultured hypothalamic astrocytes are similar to those previously reported for cultured astrocytes from the cerebellum.
The vaporization enthalpies of some crown and polyethers by correlation gas chromatography

Abstract Podands and crown ethers are an important class of solvents and metal complexing agents. The vaporization enthalpies of a series of ethers that include 18-crown-6 (87.3±2.3), dibenzo-18-crown-6 (137±7.4), dicyclohexano-18-crown-6 (mixture of diastereomers 124.2±4.0), 1,2-bis-(2-methoxyethoxy)ethane (63.7±3.3), 2,5-dimethoxy-2,5-dihydrofuran ( cis / trans mixture: 44.2±0.3) and 1,3,5-trimethoxybenzene (68.2±2.0) kJ mol −1 are evaluated by the technique of correlation gas chromatography. This technique utilizes gas chromatographic retention times measured as a function of temperature and the known vaporization enthalpies of a series of standards. Vaporization enthalpies are obtained for both liquids and solids. Sublimation enthalpies for benzo-12-crown-4 (104.3±2.6), 18-crown-6 (119.1±6.7), benzo-15-crown-5 (128.1±10.8), and dibenzo-18-crown-6 (178.8±6.9) kJ mol −1 are calculated by adding experimental fusion enthalpies to vaporization enthalpies and adjusting for temperature. Uncertainties represent two standard deviations. The results are compared to estimated values. Despite the fact that crown ethers are excellent complexing agents their thermodynamic properties associated with phase changes appear quite similar to their acyclic counterparts and similar to analogous hydrocarbons.
‘Albumin-receptor’ uptake kinetics do not require an intact lobular architecture and are not specific for albumin

When freshly isolated well-stirred single cell suspensions of rat hepatocytes were incubated with 5-600 microM [3H]oleate or [35S]sulfobromophthalein (BSP) in the presence of 150 microM bovine serum albumin (BSA), uptake of both ligands increased as a linear function of the total ligand concentration in the medium. By contrast, when the same ligand concentrations were incubated as 1:1 complexes with BSA, apparent saturation of ligand uptake was observed. Analogous results were obtained in incubations employing beta-lactoglobulin instead of BSA. In none of these studies did ligand uptake velocity correlate in simple fashion with the concentration of unbound ligand in the incubation medium. These studies establish that the basis for the kinetic observations termed the 'albumin receptor phenomenon' does not require an intact hepatic lobular architecture or space of Disse, and is not specific for albumin.
Type I error rates, power, and sample sizes for two-stage solutions to the Behrens-Fisher problem when population distributions are non-normal

Abstract Two-stage sampling procedures for comparing two population means developed by Chapman (1950) and Ghosh (1975) are compared in terms of Type I errors, power, and sample size requirements when populations are non-normal. The Ghosh procedure is shown to be less sensitive to non-normal distributions but can have actual Type I error rates greater than the nominal when sampling from distributions that are skewed and the initial sample size is small. Moderate to large sample sizes at the first sampling stage can reduce the overall total sample size needed and can minimize the inflated Type I error rate. Average sample sizes needed remain constant across distribution shapes but greater variability is found with heavy-tailed distributions. Total sample sizes needed for the Ghosh procedure were estimated for a variety of effect sizes and are compared with the Student t-test when all parametric assumptions, including equal population variances, are met. Only small differences in the sample sizes are found when the initial sample size is at least moderate.
Predictors of refusal during a multi-step recruitment process for a randomized controlled trial of arthritis education.

Objective: Randomized controlled trials in patient education often have difficulty enrolling vulnerable populations—specifically, older, poorer, and less educated individuals. We undertook a randomized controlled trial (RCT) of an educational intervention for arthritis management, which included strategies to remove literacy-related barriers to participation. This paper reports on the multi-stage recruitment process and assesses whether refusal to participate was related to education, age, gender, working status, or insurance status. Methods: The recruitment protocol was designed to eliminate literacy-related barriers to participation. Patients were never asked to read or fill out forms. Interactions were oral, using everyday terms and short, clear sentences. Patients who declined during a screening call were considered Stage 1 Refusers. Patients who initially expressed interest but neither completed a baseline questionnaire nor provided consent were considered Stage 2 Refusers. Patients who consented were considered Enrollees. Age, gender, and insurance status were compared between Stage 1 Refusers and Enrollees. A second analysis compared these variables, plus educational attainment and working status, between Stage 2 Refusers, and Enrollees. Results: Of 408 eligible patients, there were 193 (47.3%) Stage 1 Refusers, 81 (19.9%) Stage 2 Refusers and 134 (32.8%) Enrollees. A higher proportion of Stage 1 Refusers than Enrollees were 65 years old (58% vs. 37%, p = .0003). Multivariate analysis, adjusting for gender and insurance status, confirmed the effect of older age on refusal (OR = 2.3 (1.4, 3.6)). There were no significant differences between Stage 2 Refusers and Enrollees. Conclusion: We found no evidence of refusal to participate due to educational attainment, working status, insurance status, or gender. Older patients were more likely to refuse participation at the first stage of recruitment. Practice implications: Researchers should continue efforts to increase participation among older patients, particularly when studies are designed to be generalized to an elderly population as is the case with arthritis research. Strategies used in this recruitment protocol designed to remove literacy-related barriers to recruitment may be responsible for the observation that subjects with lower education did not have a higher rate of refusal. Such strategies deserve further study.
Microscopic theory for cross-linked macromolecules. I. Broken symmetry, rigidity, and topology

This paper is concerned with the onset of rigidity in randomly cross-linked macromolecules. We discuss in detail the possible partitionings of configuration space, which may accompany the spontaneous breaking of translational invariance, treating separately the cases of crystals, amorphous solids, and cross-linked macromolecules. We describe the order parameters for these systems, drawing the distinction between solids with discrete translational symmetry and solids with macroscopic translational invariance, such as randomly cross-linked macromolecular solids. We show that the latter may be described by a sequence of probability distributions for the overlaps of equilibrium states. In a cross-linked system of impenetrable linear chains, the configuration space of the solid state is partitioned into two categories of equilibrium states: those related by translational and rotational symmetry, and those unrelated by these symmetries. The latter are a consequence of the distinct topologies of the network, which are consistent with a given set of cross links. We show how the overlap-probability distributions may be calculated.
A pulse sequence for suppressing solvent lines in 13C NMR spectra

On montre comment une sequence peut etre utilisee pour supprimer selectivement des raies de 13 C de solvants non deuteries
Seasonality of selected surface water constituents in the Indian River Lagoon, Florida.

Seasonality is often the major exogenous effect that must be compensated for or removed to discern trends in water quality. Our objective was to provide a methodological example of trend analysis using water quality data with seasonality. Selected water quality constituents from 1979 to 2004 at three monitoring stations in southern Florida were evaluated for seasonality. The seasonal patterns of flow-weighted and log-transformed concentrations were identified by applying side-by-side boxplots and the Wilcoxon signed-rank test (p < 0.05). Seasonal and annual trends were determined by trend analysis (Seasonal Kendall or Tobit procedure) using the U.S. Geological Survey (USGS) Estimate TREND (ESTREND) program. Major water quality indicators (specific conductivity, turbidity, color, and chloride), except for turbidity at Station C24S49, exhibited significant seasonal patterns. Almost all nutrient species (NO 2 -N, NH 4 -N, total Kjeldahl N, PO 4 -P, and total P) had an identical seasonal pattern of concentrations significantly greater in the wet than in the dry season. Some water quality constituents were observed to exhibit significant annual or seasonal trends. In some cases, the overall annual trend was insignificant while opposing trends were present in different seasons. By evaluating seasonal trends separately from all data, constituents can be assessed providing a more accurate interpretation of water quality trends.
A dopaquinone model that mimics the water addition step of cofactor biogenesis in copper amine oxidases.

The consensus mechanism for biogenesis of the 2,4,5-trihydroxyphenylalanine quinone (TPQ) cofactor in copper amine oxidases involves a key water addition to the dopaquinone intermediate. Although hydration of o-quinones seems straightforward and was implicated previously in aqueous autoxidation of catechols to give ultimately hydroxyquinones, a recent study (Mandal, S.; Lee, Y.; Purdy, M. M.; Sayre, L. M. J. Am. Chem. Soc. 2000, 122, 3574−3584) showed that the observed hydroxyquinones arise not from hydration, but from addition to the o-quinones of H2O2 generated during autoxidation of the catechols. In the enzyme case, hydration of dopaquinone is proposed to be mediated by the active site Cu(II). To establish precedent for this mechanism, we engineered a catechol tethered to a Cu(II)-coordinating unit, such that the corresponding o-quinone could be generated in situ by oxidation with periodate (to avoid generation of H2O2). Thus, coordination of 4-((2-(bis(2-pyridylmethyl)amino)ethylamino)methyl)-1,2-ben...
Lymphoid Enhancer Factor-1 and β-Catenin Inhibit Runx2-dependent Transcriptional Activation of the Osteocalcin Promoter

Functional control of the transcription factor Runx2 is crucial for normal bone formation. Runx2 is detectable throughout osteoblast development and maturation and temporally regulates several bone-specific genes. In this study, we identified a novel post-translational mechanism regulating Runx2-dependent activation of the osteocalcin promoter. A functional binding site for the high mobility group protein lymphoid enhancer-binding factor 1 (LEF1) was found adjacent to the proximal Runx2-binding site in the osteocalcin promoter. In transcription assays, LEF1 repressed Runx2-induced activation of the mouse osteocalcin 2 promoter in several osteoblast lineage cell lines. Mutations in the LEF1-binding site increased the basal activity of the osteocalcin promoter; however, the LEF1 recognition site in the osteocalcin promoter was surprisingly not required for LEF1 repression. A novel interaction between the DNA-binding domains of Runx2 and LEF1 was identified and found crucial for LEF1-mediated repression of Runx2. LEF1 is a nuclear effector of the Wnt/LRP5/beta-catenin signaling pathway, which is also essential for osteoblast proliferation and normal skeletal development. A constitutively active beta-catenin enhanced LEF1-dependent repression of Runx2. These data identify a novel mechanism of regulating Runx2 activity in osteoblasts and link Runx2 transcriptional activity to beta-catenin signaling.