cssi/SciSciGPT-SciSciNet huggingface dataset:
Surgical approach to functional tricuspid regurgitation: should we be more aggressive?

PURPOSE OF REVIEW Functional tricuspid regurgitation (FTR) is an important clinical entity that is encountered frequently during the operative management of left-sided heart valve disease, particularly in the setting of mitral regurgitation. Failure to recognize the importance of FTR during mitral valve surgery may result in inferior early and late outcomes because of the progression of tricuspid regurgitation and right heart failure. In this review, attention is focused on recent literature, which increasingly supports the use of corrective tricuspid valve annuloplasty, and the growing consensus that FTR or tricuspid annular dilation should be more aggressively addressed at the time of cardiac surgery. RECENT FINDINGS The European Society of Cardiology and the European Association for Cardiothoracic Surgery (ESC/EACTS) 2012 guidelines recommend a more proactive approach to tricuspid regurgitation correction and highlight the shifting consensus toward more aggressive surgical therapy. Rigid annuloplasty rings should be used in favor of flexible bands or DeVega-style repairs. Preoperative determinants of clinical outcomes now include echocardiographic parameters of tricuspid valve tenting area, and associated right ventricular size and function. SUMMARY Despite data demonstrating inferior outcomes in the presence of residual tricuspid regurgitation after cardiac surgery, surgical repair for FTR appears to be underutilized. Increased recognition and correction of tricuspid regurgitation at the time of surgery is increasingly supported by published guidelines, although randomized prospective data are needed to bolster current recommendations.
A novel activity from an old compound: Manzamine A reduces the metastatic potential of AsPC-1 pancreatic cancer cells and sensitizes them to TRAIL-induced apoptosis

Purpose: Pancreatic cancer is the fourth leading cause of cancer death in the United States, and new drugs to treat the disease are needed. Pancreatic cancer cells are highly metastatic and exhibit resistance to apoptosis. Small molecules that can restore sensitivity to apoptosis or reduce metastasis would have therapeutic potential against this disease. Manzamine A is an alkaloid isolated from marine sponges that was suspected to have inhibitory activity against the mitogen activated kinase kinase (MEK). Because of this, the effects of Manzamine A were studied in pancreatic cancer cells. Methods: AsPC-1 cells were treated for 48 h in the presence of various concentrations of Manzamine A and their phenotype, cytotoxicity, cell invasion and susceptibility to apoptosis were observed. Results: Manzamine A decreased single cell formation, abrogated cell migration and restored the susceptibility of the cells to TRAIL-induced apoptosis in AsPC-1 cells. Its mechanism of action remains unknown, as manzamine A does not inhibit MEK. Conclusions: Manzamine A appears to have a formerly unrecognized activity in blocking tumor cell invasion as well as in restoring cancer cell susceptibility to apoptosis in vitro and therefore has the potential to be used as an adjuvant to existing cancer therapies.
Beyond Transport: A More Holistic Approach to Building Optical Transport Networks

Learn how to evolve your transport network with innovative solutions to support the massive bandwidth growth and dramatically changing traffic patterns resulting from datacentre proliferation and an increased dependency on cloud based services.
A Consistent Algorithm for Quasigeostrophic Energy and Energy Flux Analysis

The energy flux vector is familiar to geophysical fluid dynamics, but only in the abstract. Equations for computing the energy balance and the energy flux vector (S) for a quasigeostrophic numerical ocean model are provided in both analytic and finite difference form. The multilayer model includes wind, lateral and bottom friction, and bathymetry. The finite difference approximation to the analytic energy balance is consistent with the finite difference approximation to the quasigeostrophic potential vorticity equation. An application of the algorithms to a simple steady ocean gyre illustrates their use. This choice of the flux vector (from an infinity of possibilities) has several advantages: it is computationally convenient; it is capable of field measurement; it has nice mathematical properties in the limit of small amplitude motion; and it facilitates intuition about the dynamics.
Impact of supercritical carbon dioxide metalworking fluids on tool life in turning of sintered steel and milling of compacted graphite iron

This paper investigates the influence of supercritical carbon dioxide (scCO2 ) metalworking fluids on tool wear in two automotive manufacturing processes. scCO2 is a low-cost minimum quantity lubrication (MQL) system with excellent cooling characteristics. In valve seat machining of sintered steel with cubic boron nitride (CBN) inserts, scCO2 reduced tool wear by up to 25% and cutting forces by 10% when compared with the benchmark water-based flood metalworking fluid currently used in production operations. In end milling of compacted graphite iron (CGI) with uncoated carbide inserts, scCO2 reduced tool wear by up to 50% when compared with the currently used metalworking fluid. These results are consistent with those from other applications that show scCO2-based metalworking fluids have the potential to reduce tool wear and cutting forces when compared with commonly used water-based metalworking fluids. At the same time scCO2 is environmentally benign, eliminates metalworking fluid maintenance and disposal, and removes the major health risks associated with today’s metalworking fluids.Copyright © 2009 by ASME
Effects of laboratory exposure to sediments contaminated with polycyclic aromatic hydrocarbons on the hemocytes of the American oyster Crassostrea virginica

Abstract We have previously shown that hemocytes of American oysters collected from polycyclic aromatic hydrocarbon (PAH)-contaminated areas in the Elizabeth River, Virginia, have a lower ability to phagocytose yeast particles and a decreased expression of concanavalin A-binding sites as compared to hemocytes of oysters collected from cleaner environments. In the present study, we exposed healthy oysters to PAH-contaminated sediments of the Elizabeth River under laboratory conditions for up to 11 weeks. The data obtained indicate that exposure to the contaminated sediments induced a significant suppression in the number of Con A-binding sites as early as four weeks post exposure, but had no significant effects on the phagocytosis. On the other hand, depuration of the Elizabeth River oysters was accompanied by a steady increase in the number of hemocytes expressing Con A and phagocytosis was slightly enhanced. The sum of our data indicates that phenotypic changes are probably more sensitive to PAH exposure than functional parameters.
CONTROL OF LOW-SPEED AIRFOIL AERODYNAMICS

Nomenclature CD = drag coefficient ( = 2D/pUlc) Cf = local skin-friction coefficient ( = 2rw/pUl) CL = lift coefficient ( = 2L/pU^c) Cq = suction coefficient ( = I vw I / UQ) c = airfoil's chord D = drag force per unit span L = lift force per unit span P = instantaneous hydrostatic pressure PO = pressure outside boundary layer P = mean pressure R = wall's radius of curvature /?6* = displacement thickness Reynolds number (= Uod*/v) RO = momentum thickness Reynolds number ( = U0de/v) Re = Reynolds number based on distance from leading edge (or chord) and freestream velocity T = instantaneous temperature T = mean temperature J7, = instantaneous velocity component Uj = mean velocity component U0 = velocity outside the boundary layer t/oo = freestream velocity HI = fluctuating velocity component u* = friction velocity ( = Vr^/p) vw = normal velocity of fluid injected or withdrawn through the wall X-, = Cartesian coordinates x = streamwise distance from leading edge y = normal distance from the wall y = normal distance in wall units ( = yu*/v) Z = spanwise coordinate a. = angle of attack 6 = boundary-layer thickness 60 = momentum thickness 6* = displacement thickness /x = dynamic coefficient of viscosity v = kinematic viscosity v/u * = viscous length scale (wall unit) p = density — p~uv = tangential Reynolds stress T.W = shear stress at the wall ( = pu *) [AJo = instantaneous spanwise vorticity at the wall _ [fijo = rnean spanwise vorticity at the wall (= — [dU/dy]Q)
A practical method for measuring the H matrix of digital x-ray and cone beam CT imaging systems

Digital clinical imaging systems designed for radiography or cone-beam computed-tomography are highly shift-variant. The x-ray cone angle of such systems varies between 0° and 15°, resulting in large variations of the focal spot projection across the image field. Additionally, the variable x-ray beam incidence across the detector field creates a location-dependent asymmetric detector response function. In this paper we propose a practical method for the measurement of the angle of incidence dependent two-dimensional presampled detector response function. We also present a method for the measurement of the source radiance at the center of the detector, and provide a geometric transformation for reprojecting given any location in object space. The measurement procedure involves standard, readily available tools such as a focal-spot/pinhole camera, and an edge. Using the measured data and a model based on smooth functions derived from Monte Carlo simulations we obtain the location-dependent detector response function. In this paper we ignore scatter, therefore the resulting location dependent system response is a function of the focal spot and detector response. The system matrix, a representation of the full deterministic point response of the system for all positions in object space, can then be calculated. The eigenvalues and eigenvectors of the system matrix are generated and interpreted.
Identification of Phosphate Binding Residues of Escherichia coli ATP Synthase

Four positively-charged residues, namely βLys-155, βArg-182, βArg-246, and αArg-376 have been identified as Pi binding residues in Escherichia coli ATP synthase. They form a triangular Pi binding site in catalytic site βE where substrate Pi initially binds for ATP synthesis in oxidative phosphorylation. Positive electrostatic charge in the vicinity of βArg-246 is shown to be one important component of Pi binding.
Empirical Bayes estimation in finite population sampling under functional measurement error models

Abstract The paper considers simultaneous estimation of finite population means for several strata. A model-based approach is taken, where the covariates in the super-population model are subject to measurement errors. Empirical Bayes (EB) estimators of the strata means are developed and an asymptotic expression for the MSE of the EB estimators is provided. It is shown that the proposed EB estimators are “first order optimal” in the sense of Robbins [1956. An empirical Bayes approach to statistics. In: Proceedings of the Third Berkeley Symposium on Mathematical Statistics and Probability, vol. 1, University of California Press, Berkeley, pp. 157–164], while the regular EB estimators which ignore the measurement error are not.
Occurrence of a winged perispore in a new world species of polypodium

Spores ofPolypodium chnoodes Spreng. were found to possess a large winged perispore surrounding the exospore. This character had hitherto been found only in the closely related families of the aspidioid-dennstaedtioid complex. Its presence in a species ofPolypodium is another example of the remarkable parallelisms which occur in ferns.
Reframing the debate over assisted colonization

Assisted colonization – also known as managed relocation or assisted migration – is one way of facilitating range shifts for species that are restricted in their ability to move in response to climate or other environmental changes. Over the past decade, a healthy debate has evolved in the scientific community over the costs and benefits of assisted colonization as a climate-adaptation strategy. This discussion has focused largely on the specific risks and benefits of intentionally moving species, and has led to the development of multiple frameworks and numerous recommendations for weighing and evaluating these factors. Here, we argue that this debate is, in part, misguided, and that a more productive discussion would result if the issue were reframed in light of (1) the goals of assisted colonization, (2) the realities of projected climate impacts, and (3) the use of complementary adaptation strategies, such as enhancing landscape connectivity.
High temperature solar thermochemical processing—hydrogen and sulfur from hydrogen sulfide

Abstract Sunlight, concentrated to high intensities, has a rarely recognized potential for adding process heat to reactors at high temperatures. Hydrogen sulfide is a by-product of the sweetening of fossil fuels. In this paper, we use, as an example, the production of hydrogen and sulfur from hydrogen sulfide as a device for showing how solar processing might be considered as a successor to a currently used industrial process, the Claus process. We conclude that this and other processes should be explored as means of using as well as storing solar energy.
Delineation of separate transport systems in rat kidney cortex for L-lysine and L-cystine by developmental patterns.

Abstract L-Cystine uptake by newborn rat kidney cortex in vitro is impaired and does not reach the normal adult level until fifteen days of age. L-lysine uptake by young cortex, on the other hand, is comparable to that observed in adults. Exchange diffusion of lysine in the newborn's cortex is also similar to adult tissue. Cystine uptake by newborn cortex is impaired further with sodium deprivation while that of lysine is markedly increased in the absence of sodium. These developmental differences argue against the concept of a common transport process for these two amino acids.
Asymptotic Crack-Tip Fields in Perfectly Plastic Solids Under Combined In-Plane and Out-of-Plane Shear Loading Conditions

In this paper, governing equations and solutions for asymptotic singular and non-singular crack-tip sectors in perfectly plastic materials are first summarized under combined in-plane and out-of-plane shear loading conditions. The crack-tip fields under mixed mode II/III loading conditions are then investigated. An assembly of crack-tip sectors is adopted with stress discontinuities along the border of the two constant stress sectors. The solutions of the crack-tip fields under pure mode II, mixed mode II/III, and nearly pure mode III loading conditions are presented. The trends of the angular variations of the mixed mode II/III crack-tip stresses agree with those of the available computational analysis and the asymptotic analysis for low strain hardening materials. The pure mode II crack-tip stresses are similar to those of Hutchinson and the nearly pure mode III stresses are similar to those of the pure mode III crack-tip field of Rice.Copyright © 2005 by ASME
Role of oncologists and primary care physicians in providing follow-up care to non-Hodgkin lymphoma survivors within 5 years of diagnosis: a population-based study

The growing population of non-Hodgkin lymphoma (NHL) survivors living longer with high physical and psychological treatment burden, in combination with the projected shortage of medical professionals, necessitates redesigning cancer follow-up care. This study examined follow-up care patterns, factors associated with follow-up care, and attitudes towards follow-up care among NHL survivors. We surveyed survivors of aggressive NHL 2 to 5 years post-diagnosis (N = 363) using a population-based sample from the Los Angeles County Surveillance Epidemiology and End Results registry. Most survivors (82 %) received cancer-related follow-up care in the past year from an oncologist. History of recurrence, more comorbidities, more symptoms, and a shorter survivor–oncologist relationship were associated with high-frequency care with the oncologist [(≥5 visits in the past year), p < 0.05]. Many survivors followed up by oncologists (71 %) also saw a primary care provider (PCP) and 47 % also saw both a PCP and other specialists. Factors associated with seeing a PCP in addition to an oncologist included more symptoms, more health information needs, no history of recurrence, perceived excellent quality of cancer follow-up care, and fewer visits with the oncologist (p < 0.05). Survivors generally reported high reassurance from, and low negative anticipation towards, follow-up care. The high proportion of NHL survivors receiving care from multiple physicians, and the sizable proportion (∼30 %) who have not recently seen a PCP, suggests that coordinating care across specialties is critical to ensure comprehensive, non-duplicative care. Understanding factors associated with cancer-related follow-up is a first step towards more effective, efficient, patient-centered care.
Beyond Risks and Rates in Obstetric Care

: Is there a pattern to past errors in perinatal care? Who is invested with the right to err? The errors most often made-the failure of regional perinatal care to accelerate the decline in infant mortality, and burgeoning technology to have much impact on mortality and morbidity-come from taking an overly narrow, technological view of pregnancy and childbirth. Yet the people we invest with the right to err are those whose focus is most narrow, technical, and medical. This focus has promoted viewing the fetus as separate from the mother and increasingly as her adversary. Past errors in perinatal care, such as the DES tragedy and reliance on x-rays, diuretics, and other short-lived fashions, might have been avoided if pregnancy and birth had been seen in a broader social context.
Hydrophobically modified acrylamide‐based polybetaines. II. Interaction with surfactants in aqueous solution

The interaction of hydrophobically modified (HM) polybetaines with selected small molecule surfactants in aqueous solution was investigated using rheological and surface tension analyses. The polymers included acrylamide-based, HM polybetaines containing N-butylphenylacrylamide (BPAM) and specified amounts of sulfobetaine, 3-(2-acrylamido-2-methylpropanedimethylammonio)-1-propanesulfonate (AMPDAPS), or carboxybetaine, 4-(2-acrylamido-2-methylpropyldimethylammonio)butanoate (AMPDAB); corresponding control (co)polymers lacking BPAM and/or betaine comonomer(s) were also examined for comparative purposes. Low charge density terpolymers exhibited greater viscosity enhancement with the addition of surfactant compared to the high charge density terpolymers. The addition of sodium dodecyl sulfate (SDS) produced the largest increase in solution viscosity, while N-dodecyl-N,N,N-trimethylammonium bromide (DTAB), N-dodecyl-N,N-dimethylammonio-1-propanesulfonate (SB3–12), and Triton X-100 enhanced polymer solution viscosity to a lesser degree. In most cases, the high charge density carboxybetaine terpolymer exhibited diminished solution viscosity upon surfactant addition. The polymers lacking hydrophobic modification showed no detectable viscosity enhancement in the presence of surfactants. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 658–671, 2004
Blunt Aortic Injury in a Patient With Prior Coronary Artery Bypass Surgery

Traumatic aortic rupture is a significant challenge, further complicated by prior coronary artery bypass graft surgery with a left internal mammary artery anastomosis. We present a patient with prior coronary artery bypass graft and valve replacement who sustained multiple injuries, including an aortic rupture, after a motor vehicle crash. This report describes successful treatment of a patient with a thoracic endograft and carotid subclavian bypass to preserve the left internal mammary artery inflow.
A Statistical-Dynamical Study of Empirically Determined Modes of Atmospheric Variability

The observed wintertime intraseasonal variability of the northern hemisphere midtropospheric circulation is analyzed within the framework of an equivalent barotropic model. The data set and the form of the eigenvalue/vector problem in the wave domain are described, and the statistical significance of the empirical orthogonal functions (EOFs) is discussed, and some selected modes are briefly described. The anomaly model and the transformation to the EOF domain are presented together with a discussion of the model coefficients and forcing term. The fitting procedure for the parameterized terms are described and the level of correspondence between the modelled and observed streamfunction tendencies as a function of the EOFs is examined. The stability of the time mean flow and other base states is investigated.
Second order nonlinear optics with long range surface plasmon polaritons

The long-range surface plasmon polaritons are shown to enable phase -matching in the three wave nonlinear optical interactions opening exiting possibilities for efficient on chip frequency conversion and parametric generation.
Orbital Self-Consistent-Field Theory. I. General Theory for Multiconfigurational Wave Functions

A general formulation of multiconfigurational self-consistent-field theory is given. The fundamental condition to be satisfied by the $M$ occupied orbitals ${\ensuremath{\psi}}_{\ensuremath{\mu}}$ of an $N(\ensuremath{\le}M)$-body system, in order that the total energy of one state be extremalized, is expressed in terms of the fundamental invariant $\mathbf{\ensuremath{\varrho}}=\ensuremath{\Sigma}{\ensuremath{\mu}=1}^{M}|{\ensuremath{\psi}}_{\ensuremath{\mu}}〉〈{\ensuremath{\psi}}_{\ensuremath{\mu}}|$. The condition placed on $\mathbf{\ensuremath{\varrho}}$ is of the same form as the condition on the fundamental invariant of the Hartree-Fock theory. Setting $M=N$, we derive the unrestricted Hartree-Fock equations from the condition on $\mathbf{\ensuremath{\varrho}}$. For $MgN$ there are three freedoms one may take with the fundamental condition on $\mathbf{\ensuremath{\varrho}}$. Exploiting any or all of these freedoms yields alternative forms of the fundamental condition. This enables us to derive an effective one-body Hamiltonian which is the sum of a Hartree-type Hamiltonian and a correlation and exchange operator. For finite $MgN$, the one-body Hamiltonian contains a nonlocal exchange and correlation operator. This operator is defined in terms of the one- and two-body density matrices. The connection between the orbitals of this theory and those of the Hartree-Fock theory is explored. The theory as outlined here is applicable to any system of $N$ identical particles, but our discussion is oriented towards electronic systems. The theory contains most self-consistent-field theories as special cases, and gives a basis for the self-consistent-field formulation of others.
There is no such thing as free support

Every campus department needs computer support, from ordering and setting up new computers to installing software and answering software questions. This is in addition to training classes, local area network support, access to centrally supported systems (such as email, calendaring, network services, and administrative systems), maintenance programs, and a variety of other computer-related issues. Who supports these departments? Large departments may be able to hire or contract a full-time support person, but what about smaller departments? What about continuity of services when a support staff member leaves for another job or a student employee graduates? Also, a single support person has expertise in particular areas but may not be well-versed in all campus-wide issues. The Iowa State University (ISU) Administrative Data Processing (ADP) Center provides support to both large and small departments on campus through a charge-back system. The charges are based on the number of computers and printers within a department, so a small department pays much less than a large department, but receives the same level of support and services. This paper is intended for directors, help center/desk professionals, managers, and system administrators. This paper lists the details of the current microcomputer support plan and describes the cost to departments. Services provided to the supported departments will be listed and discussed in-depth. Future goals of the ADP Center will also be discussed.
Simulation analysis of LER and dose tradeoffs for EUV resists with photo-decomposable quenchers

The SuMMIT stochastic simulator has been used to conduct a simulation study of photo-decomposable quencher (PDQ) based EUV resists and performance comparison between PDQ resists and conventional quencher (regQ) resists analyzed from the standpoint of dose and LER metrics. The dose and LER Tradeoffs have been analyzed as a function of base loading, base diffusion lengths and relative deprotection/quenching rates. About 3.5% LER improvements with PDQ has been predicted at a dose of 15 mJ/cm2 with base loaded at 20% of PAG loading, for 25 nm half-pitch line-space patterns. Dose savings of 2 mJ/cm2 and LER improvement of 0.1 nm between regQ and PDQ resists are predicted with a base diffusion length equal to the acid diffusion length of 10 nm, and base loaded at 30% of PAG loading. Dose improvements of 1 mJ/cm2 for equal regQ and PDQ LERs of 3.5 nm is possible at a deprotection rate that is half as fast as the acid/base quenching rate of 10 nm3/s. Improvement in the deprotection gradient is found to be the dominant factor behind lower PDQ LERs, while the difference in deprotection noise between conventional quenchers and PDQs is found to be marginal.
Piezoelectric slotted ring transducer

Analytical treatment of a slotted piezoelectric ceramic ring transducer vibrating in flexure is presented. The mode shape of the slotted ring vibration is determined, and parameters of the equivalent electromechanical circuit of the transducer are calculated. Possibilities to optimize the effective electromechanical coupling coefficient of the transducer by combining active and passive materials are considered. Acoustic loading for typical projectors made from slotted rings is estimated. Challenges in implementing the slotted ring transducers in terms of depth limitation and radiated power are discussed.
United Time-Frequency Spectroscopy for Dynamics and Global Structure

Ultrashort laser pulses have thus far been used in two distinct modes. In the time domain, the pulses have allowed probing and manipulation of dynamics on a subpicosecond time scale. More recently, phase stabilization has produced optical frequency combs with absolute frequency reference across a broad bandwidth. Here we combine these two applications in a spectroscopic study of rubidium atoms. A wide-bandwidth, phase-stabilized femtosecond laser is used to monitor the real-time dynamic evolution of population transfer. Coherent pulse accumulation and quantum interference effects are observed and well modeled by theory. At the same time, the narrow linewidth of individual comb lines permits a precise and efficient determination of the global energy-level structure, providing a direct connection among the optical, terahertz, and radio-frequency domains. The mechanical action of the optical frequency comb on the atomic sample is explored and controlled, leading to precision spectroscopy with an appreciable reduction in systematic errors.
Instruction scheduling based on energy and performance constraints

Reducing energy consumption has become an important issue in designing hardware and software systems in recent years. Although low power hardware components are critical for reducing energy consumption, the switching activity, which is the main source of dynamic power dissipation in electronic systems, is largely determined by the software running on these systems. In this paper we present and evaluate several instruction scheduling algorithms that reorder a given sequence of instructions taking into account the energy considerations. We first compare a performance-oriented scheduling technique with three energy-oriented instruction scheduling algorithms from both performance (execution cycles of the resulting schedules) and energy consumption points of view. Then, we propose three scheduling algorithms that consider energy and performance at the same time. The results obtained show that these techniques are quite successful in reducing energy consumption and their performance is comparable to that of a pure performance-oriented scheduling.
Audio Classification of Bird Species: A Statistical Manifold Approach

Our goal is to automatically identify which species of bird is present in an audio recording using supervised learning. Devising effective algorithms for bird species classification is a preliminary step toward extracting useful ecological data from recordings collected in the field. We propose a probabilistic model for audio features within a short interval of time, then derive its Bayes risk-minimizing classifier, and show that it is closely approximated by a nearest-neighbor classifier using Kullback-Leibler divergence to compare histograms of features. We note that feature histograms can be viewed as points on a statistical manifold, and KL divergence approximates geodesic distances defined by the Fisher information metric on such manifolds. Motivated by this fact, we propose the use of another approximation to the Fisher information metric, namely the Hellinger metric. The proposed classifiers achieve over 90% accuracy on a data set containing six species of bird, and outperform support vector machines.
Fluorosis risk from early exposure to fluoride toothpaste.

Abstract– Swallowed fluoride toothpaste in the early years of life has been postulated to be a risk factor for fluorosis, but the epidemiological evidence is weakened by the fact that most of the relevant studies were done in developed countries where an individual is exposed to multiple sources of fluoride. Objectives: To quantify the risk of fluorosis from fluoride toothpaste in a population whose only potential source of fluoride was fluoride toothpaste. Methods: Case-control analyses were conducted to test the hypothesis that fluoride toothpaste use before the age of 6 years increased an individual's risk of fluorosis. Data came from a cross-sectional clinical dental examination of schoolchildren and a self-administered questionnaire to their parents. The study was conducted in Goa, India. The study group consisted of 1189 seventh grade children with a mean age of 12.2 years. Results: The prevalence of fluorosis was 12.9% using the TF index. Results of the crude, stratified, and logistic regression analyses showed that use of fluoride toothpaste before the age of 6 years was a risk indicator for fluorosis (OR 1.83, 95% CI 1.05–3.15). Among children with fluorosis, beginning brushing before the age of 2 years increased the severity of fluorosis significantly (P < 0.001). Other factors associated with the use of fluoride toothpaste, such as eating or swallowing fluoride toothpaste and higher frequency of use, did not show a statistically significant increased risk for prevalence or severity of fluorosis. Conclusions: Fluoride toothpaste use before the age of 6 years is a risk indicator for fluorosis in this study population.
Vitamin D, folate, and potential early lifecycle environmental origin of significant adult phenotypes.

Background and objectives: Vitamin D and folate are highly UV sensitive, and critical for maintaining health throughout the lifecycle. This study examines whether solar irradiance during the first trimester of pregnancy influences vitamin D receptor (VDR) and nuclear folate gene variant occurrence, and whether affected genes influence late-life biochemical/clinical phenotypes. Methodology: 228 subjects were examined for periconceptional exposure to solar irradiance, variation in vitamin D/folate genes (polymerase chain reaction (PCR)), dietary intake (food frequency questionnaire (FFQ)) and important adult biochemical/clinical phenotypes. Results: Periconceptional solar irradiance was associated with VDR-BsmI (P = 0.0008wk7), TaqI (P = 0.0014wk7) and EcoRV (P = 0.0030wk6) variant occurrence between post-conceptional weeks 6–8, a period when ossification begins. Similar effects were detected for other VDR gene polymorphisms. Periconceptional solar irradiance was also associated with 19 bp del-DHFR (P = 0.0025wk6), and to a lesser extent C1420T-SHMT (P = 0.0249wk6), a folate-critical time during embryogenesis. These same genes were associated with several late-life phenotypes: VDR-BsmI, TaqI and ApaI determined the relationship between dietary vitamin D and both insulin (P < 0.0001/BB, 0.0007/tt and 0.0173/AA, respectively) and systolic blood pressure (P = 0.0290/Bb, 0.0299/Tt and 0.0412/AA, respectively), making them important early and late in the lifecycle. While these and other phenotype associations were found for the VDR variants, folate polymorphism associations in later-life were limited to C1420T-SHMT (P = 0.0037 and 0.0297 for fasting blood glucose and HbA1c levels, respectively). We additionally report nutrient–gene relationships with body mass index, thiol/folate metabolome, cognition, depression and hypertension. Furthermore, photoperiod at conception influenced occurrence of VDR-Tru9I and 2R3R-TS genotypes (P = 0.0120 and 0.0360, respectively). Conclusions and implications: Findings identify environmental and nutritional agents that may interact to modify gene–phenotype relationships across the lifecycle, offering new insight into human ecology. This includes factors related to both disease aetiology and the evolution of skin pigmentation.
The call-by-need lambda calculus

Plotkin (1975) showed that the lambda calculus is a good model of the evaluation process for call-by-name functional programs. Reducing programs to constants or lambda abstractions according to the leftmost-outermost strategy exactly mirrors execution on an abstract machine like Landin's SECD machine. The machine-based evaluator returns a constant or the token closure if and only if the standard reduction sequence starting at the same program will end in the same constant or in some lambda abstraction. However, the calculus does not capture the sharing of the evaluation of arguments that lazy implementations use to speed up the execution. More precisely, a lazy implementation evaluates procedure arguments only when needed and then only once. All other references to the formal procedure parameter re-use the value of the first argument evaluation. The mismatch between the operational semantics of the lambda calculus and the actual behavior of the prototypical implementation is a major obstacle for compiler writers. Unlike implementors of the leftmost-outermost strategy or of a call-by-value language, implementors of lazy systems cannot easily explain the behavior of their evaluator in terms of source level syntax. Hence, they often cannot explain why a certain syntactic transformation ‘works’ and why another doesn't. In this paper we develop an equational characterization of the most popular lazy implementation technique – traditionally called ‘call-by-need’ – and prove it correct with respect to the original lambda calculus. The theory is a strictly smaller theory than Plotkin's call-by-name lambda calculus. Immediate applications of the theory concern the correctness proofs of a number of implementation strategies, e.g. the call-by-need continuation passing transformation and the realization of sharing via assignments. Some of this material first appeared in a paper presented at the 1995 ACM Conference on the Principles of Programming Languages. The paper was a joint effort with Maraist, Odersky and Wadler, who had independently developed a different equational characterization of call-by-need. We contrast our work with that of Maraist et al. in the body of this paper where appropriate.
Amelioration of Bacterial Genomes: Rates of Change and Exchange

Although bacterial species display wide variation in their overall GC contents, the genes within a particular species' genome are relatively similar in base composition. As a result, sequences that are novel to a bacterial genome—i.e., DNA introduced through recent horizontal transfer—often bear unusual sequence characteristics and can be distinguished from ancestral DNA. At the time of introgression, horizontally transferred genes reflect the base composition of the donor genome; but, over time, these sequences will ameliorate to reflect the DNA composition of the new genome because the introgressed genes are subject to the same mutational processes affecting all genes in the recipient genome. This process of amelioration is evident in a large group of genes involved in host-cell invasion by enteric bacteria and can be modeled to predict the amount of time required after transfer for foreign DNA to resemble native DNA. Furthermore, models of amelioration can be used to estimate the time of introgression of foreign genes in a chromosome. Applying this approach to a 1.43-megabase continuous sequence, we have calculated that the entire Escherichia coli chromosome contains more than 600 kb of horizontally transferred, protein-coding DNA. Estimates of amelioration times indicate that this DNA has accumulated at a rate of 31 kb per million years, which is on the order of the amount of variant DNA introduced by point mutations. This rate predicts that the E. coli and Salmonella enterica lineages have each gained and lost more than 3 megabases of novel DNA since their divergence.
Correlating Stiffness, Ductility, and Morphology of Polymer:Fullerene Films for Solar Cell Applications

The development of flexible and physically robust organic solar cells requires detailed knowledge of the mechanical behavior of the heterogeneous material stack. However, in these devices there has been limited research on the mechanical properties of the active organic layer. Here, two critical mechanical properties, stiffness and ductility, of a widely studied organic solar cell active layer, a blend film composed of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) are reported. Processing conditions are varied to produce films with differing morphology and correlations are developed between the film morphology, mechanical properties and photovoltaic device performance. The morphology is characterized by fitting the absorption of the P3HT:PCBM films to a weakly interacting H-aggregate model. The elastic modulus is determined using a buckling metrology approach and the crack onset strain is determined by observing the film under tensile strain using optical microscopy. Both the elastic modulus and crack onset strain are found to vary significantly with processing conditions. Processing methods that result in improved device performance are shown to decrease both the compliance and ductility of the film.
Global CO2storage potential of self‐sealing marine sedimentary strata

[1] One potential way to geologically sequester captured CO2 emissions is to inject them below the seafloor into marine sedimentary strata where pressures and temperatures would trap the CO2through “self-sealing” gravitational and hydrate-formation mechanisms. Here we map out the worldwide distribution and thicknesses of such self-sealing strata using a comprehensive, global dataset of deep-sea sediment cores in combination with digital grids of ocean floor heat flow, bathymetry, and sediment thickness. Based on our mapping, we estimate that the total bulk sediment volume of self-sealing strata is 63 million cubic kilometers, 0.8–1.4 km3 (or ∼1.3–2.7%) of which are sands with intrinsic permeability suitable for storing CO2. This is enough storage capacity to hold between 1,260–28,500 gigatonnes of CO2, or about 40–1,000 y of total global CO2 emissions. However, the storage capacity is unevenly distributed where it lies within the Exclusive Economic Zones (EEZ) of the world's largest CO2 emitting economies. The United States and India respectively release 16% and 62% of their annual CO2emissions (or 1 Bt/y and 800 Mt/y) within 500 km of self-sealing sands located in their EEZs, while only 6% of the annual emissions from China and the European Union (or 330 Mt/y and 250 Mt/y, respectively) occur within this distance.
Periplasmic Nitrate Reductase (NapABC Enzyme) Supports Anaerobic Respiration by Escherichia coli K-12

Periplasmic nitrate reductase (NapABC enzyme) has been characterized from a variety of proteobacteria, especially Paracoccus pantotrophus. Whole-genome sequencing of Escherichia coli revealed the structural genes napFDAGHBC, which encode NapABC enzyme and associated electron transfer components. E. coli also expresses two membrane-bound proton-translocating nitrate reductases, encoded by the narGHJI and narZYWV operons. We measured reduced viologen-dependent nitrate reductase activity in a series of strains with combinations of nar and nap null alleles. The napF operon-encoded nitrate reductase activity was not sensitive to azide, as shown previously for the P. pantotrophus NapA enzyme. A strain carrying null alleles of narG and narZ grew exponentially on glycerol with nitrate as the respiratory oxidant (anaerobic respiration), whereas a strain also carrying a null allele of napA did not. By contrast, the presence of napA+ had no influence on the more rapid growth of narG+ strains. These results indicate that periplasmic nitrate reductase, like fumarate reductase, can function in anaerobic respiration but does not constitute a site for generating proton motive force. The time course of phi(napF-lacZ) expression during growth in batch culture displayed a complex pattern in response to the dynamic nitrate/nitrite ratio. Our results are consistent with the observation that phi(napF-lacZ) is expressed preferentially at relatively low nitrate concentrations in continuous cultures (H. Wang, C.-P. Tseng, and R. P. Gunsalus, J. Bacteriol. 181:5303-5308, 1999). This finding and other considerations support the hypothesis that NapABC enzyme may function in E. coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme.
Minority-carrier thermoelectric devices

Traditional Peltier coolers employ majority carriers within doped semiconductor regions to transport heat energy between metal contacts. An alternative approach to using such coolers in an external fashion to cool electronic devices is to optimize the thermoelectric performance of the electronic devices themselves. Recognizing that minority carriers play an important role in many electronic and optoelectronic devices, we have developed a general theory for thermoelectric effects in a p-n diode (a prototypical electronic and optoelectronic component) where diffusion of minority carriers is essential to the device's operation. Differences with the traditional Peltier effect are highlighted. It is also shown that the heat energy can be transported from the diode junction to the side contacts, producing temperature gradients within the device and internally cooling the junction. Analytic expressions for quantities such as the effective ZT are derived, as well as optimization conditions for doping, region width, and current density. Predicted heat gradients over micron-scale devices are approximately 7 degrees for InGaAs and 30 degrees for HgCdTe under optimal heat-sinking conditions. Other numerical results are given for several common material systems.
A Model of the Effect of Affect on Economic Decision Making

The standard economic model of decision making assumes a decision maker’s current emotional state has no impact on his or her decisions. Yet there is a large psychological literature that shows that current emotional state, in particular mild positive affect, has a significant effect on decision making, problem solving, and behavior. This paper offers a way to incorporate this insight from psychology into economic modelling. Moreover, this paper shows that this simple insight can parsimoniously explain a wide variety of behaviors.
Role of solute carriers in response to anticancer drugs

Membrane transporters play critical roles in moving a variety of anticancer drugs across cancer cell membrane, thereby determining chemotherapy efficacy and/or toxicity. The retention of anticancer drugs in cancer cells is the result of net function of efflux and influx transporters. The ATP-binding cassette (ABC) transporters are mainly the efflux transporters expressing at cancer cells, conferring the chemo-resistance in various malignant tumors, which has been well documented over the past decades. However, the function of influx transporters, in particular the solute carriers (SLC) in cancer cells, has only been recently well recognized to have significant impact on cancer therapy. The SLC transporters not only directly bring anticancer agents into cancer cells but also serve as the uptake mediators of essential nutrients for tumor growth and survival. In this review, we concentrate on the interaction of SLC transporters with anticancer drugs and nutrients, and their impact on chemo-sensitivity or -resistance of cancer cells. The differential expression patterns of SLC transporters between normal and tumor tissues may be well utilized to achieve specific delivery of chemotherapeutic agents.
Determination of lubricant film thickness on a particulate disk surface by atomic force microscopy

The ability of the atomic force microscope (AFM) to measure the lubricant film thickness on the surface of particulate disks is demonstrated, and experimental results are presented. AFM measure the thickness of the lubricant film at a particular location on the disk surface with a lateral resolution of the order of the AFM tip radius, approximately 1000 AA. For an unused disk, 50-70 AA of lubricant thickness is found. After the disk has been in use for several years, the lubricant thickness decreases to 35-55 AA. In both cases, the lubricant is uniformly distributed on the disk surface, although somewhat more uniformly on the used disk. For all types of disks studied, most of the lubricant resides below the disk surface, presumably in the medium's porosity, with only a molecular thin film of lubricant on the surface. >
Intraparticle phosphorus diffusion in a drinking water treatment residual at room temperature

Phosphorus (P) has been recognized as one of the major limiting nutrients that are responsible for eutrophication of surface waters, worldwide. Efforts have been concentrated on reducing P loads reaching water bodies, via surface runoff and/or leaching through a soil profile. Use of drinking water treatment residuals (WTRs) is an emerging cost-effective practice to reduce soluble P in poorly P-sorbing soils or systems high in P. Literature suggests that WTRs have huge P sorption capacities. We hypothesized that P sorption would be limited by diffusional constraints imposed by the WTR particles. Selected chemical and physical (specific surface area, particle size distribution) characteristics of an iron-based WTR were measured. Sorption P isotherms at room temperature were constructed, and sorption kinetics were monitored. An intraparticle diffusion model was utilized to fit the kinetic data. Results showed that the WTR dramatically reduced soluble P, showing nonequilibrium characteristics, even after 80 d of reaction. Specific surface area (SSA) measured with CO 2 gas was significantly greater than the traditional BET–N2 value (28 versus 3.5 m 2 g −1 ), suggesting that a large amount of internal surfaces might be present in the WTR. The intraparticle P diffusion model was modified to include the wide particle size distribution of the WTR. The intraparticle diffusion model fitted the data well (r 2 = 0.83). We calculated a maximum apparent P diffusion coefficient value of 4 × 10 −15 cm 2 s −1 ,w hich agrees with published values for intraparticle diffusion in microporous sorbents. This work may be useful for predicting long-term sorption characteristics of WTRs, since WTRs have been suggested as potential long-term immobilizers of sorbed P in P-sensitive ecosystems.