cssi/SciSciGPT-SciSciNet huggingface dataset:
The performance of different lookback periods and sources of information for Charlson comorbidity adjustment in Medicare claims.

Background The Charlson Score is a particularly popular form of comorbidity adjustment in claims data analysis. However, the effects of certain implementation decisions have not been empirically examined. Objective To determine the effects of alternative data sources and lookback periods on the performance of Charlson scores in the prediction of mortality following hospitalization. Subjects A representative sample of 1,387 elderly patients hospitalized in 1993, drawn from the Medicare Current Beneficiary Survey (MCBS). Three years of linked Medicare claims and survey instruments were available for all patients, as was 2-year mortality follow-up. Statistical methods Nested Cox regression and comparisons of areas under the Receiver Operating Characteristic (ROC) curve were used to evaluate ability to predict mortality. Results Compared with a 1-year lookback involving solely inpatient claims, statistically and empirically significant improvements in the prediction of mortality are obtained by incorporating alternative sources of data (particularly 2 years of inpatient data and 1 year of outpatient and auxiliary claims), but only if indices derived from distinct sources of data are entered into the regression distinctly. The area under the ROC curve for 1-year mortality predication increases from 0.702 to 0.741 (P = 0.002). Furthermore, these improvements in explanatory power obtained whether one also controls for Charlson scores based on self-reported health history and/or secondary diagnoses from the claim for the index hospitalization itself. Finally, claims-based comorbidity adjustment performs comparably to survey-derived adjustment, with areas under the ROC curve of 0.702 and 0.704, respectively. Conclusions The widespread practice of comorbidity adjustment in pre-existing administrative data sources can be improved by taking more complete advantage of existing administrative data sources.
Mechanistic study of the samarium diiodide—N,N-dimethyl-2-aminoethanol reducing system

Abstract The impact of N,N -dimethyl-2-aminoethanol (DMAE) on the reactivity of SmI 2 is presented. The SmI 2 –DMAE reagent system is capable of reducing a range of substrates including alkyl halides, ketones, lactones, and arenes. Mechanistic studies on anthracene reduction are consistent with a system that proceeds through a highly ordered, early transition state requiring 2 equiv of DMAE and 1 equiv of anthracene and Sm(II).
A comparative cost analysis of biodiesel, compressed natural gas, methanol, and diesel for transit bus systems

Abstract A comparison of operating costs for buses used in a transit system are investigated considering four alternative fuels: biodiesel, compressed natural gas, methanol, and diesel. Rust's `nested fixed point' maximum likelihood estimation algorithm is used in this comparison. The algorithm considers both tangible costs such as fuel, maintenance, and infrastructure, and intangible costs associated with different levels of bus engine operating reliability under alternative fuels. Using data on actual monthly mileage and time of engine rebuilds under the four alternative fuels, the Rust algorithm is employed assuming that an optimal maintenance strategy is adopted for each alternative fuel type. Results indicate that although biodiesel and biodiesel blends have higher total costs than diesel fuel, they have the potential of competing with CNG and methanol as fuels for urban transit buses.
Calculation of thermodynamic and transport properties of intrinsic point defects in silicon

A systematic analysis is presented for the calculation of thermodynamic and transport properties of intrinsic point defects in silicon based on atomistic simulations using the Stillinger-Weber interatomic potential [F. H. Stillinger and T. A. Weber, Phys. Rev. B 31, 5262 (1985)]. Results are computed from a robust combination of lattice statics and Monte Carlo simulations, the quasiharmonic approximation for calculation of reference-state free energies, and the cumulant analysis of the enthalpy distribution function. Results are presented for formation properties and thermal equilibrium concentrations of vacancies and self-interstitials and for transport properties of vacancies in silicon. The calculated formation properties and thermal equilibrium concentrations of both intrinsic point defects and the migration enthalpy of the vacancy are in reasonable quantitative agreement with experimental data and analyses of dopant diffusion data. The calculations support the extended interstitial model and provide an internally consistent data base for constitutive and numerical modeling of substitutional species transport in silicon.
Untangling the Relationship Between Mental Health and Homelessness Among a Sample of Arrestees

Past research has focused on the intertwined relationship between homelessness, mental illness, and criminal justice. Although a well-established correlation between mental illness and homelessness has emerged, a better understanding of how this may be mediated by other prominent risk factors such as substance use or victimization is warranted. The current study uses data obtained from 3,673 recently booked arrestees to examine these relationships. Using structural equation modeling with measured variables, the analyses indicate the relationship between mental health and homelessness to be almost entirely mediated by alcohol use, drug use, and violent victimization. Policy implications are discussed.
Conifer seed predation in harvested and burned dry Douglas-fir forests in southern British Columbia

Consumption of seeds of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) was measured in dry Douglas-fir forest at the Opax Mountain Silvicultural Systems site and a nearby burned area as one component of understanding limited natural regeneration in these sites. Seeds were placed in plots surrounded by a physical barrier to invertebrates, enclosed in mesh impermeable to small mammals, covered by litter, or unprotected in clear-cut, partially harvested, uncut, and burned areas and monitored for three several-day sessions in 2 years. Daily survival rates of unprotected seeds of both species were equally low: 0.63 in uncut forest, 0.45 in partially harvested and clear-cut sites, and 0.03 in the burned area. Experimental reductions of coarse woody debris reduced seed predation moderately in patch cuts but not in uncut forest. Litter cover or selective exclosure of ground-dwelling invertebrates reduced seed losses only slightly, whereas small mamm...
Telehealth research and evaluation: implications for decision makers

Society must answer questions about health information technology applications or telehealth that lead to the best allocation of resources for maintaining and improving the health status of our population. These questions deal with the adoption and deployment of telehealth for improving the health and well-being of the members of society, compared with alternative means. From the less than overwhelming response to the "build it and they will come" approach, we clearly have insufficient evidence of the medical effectiveness, cost effectiveness, and patient and provider satisfaction with telehealth solutions. The Agency for Health Care Policy and Research (AHCPR) is a federal research agency in the US that supports research to find out what is effective in improving the quality of and access to health services in the community, what is the impact on patient outcomes, and what is the cost of obtaining those outcomes. Telehealth decision makers need studies of telehealth technologies that focus on specific clinical conditions in narrowly concentrated applications and that use scientific methods to compare outcomes and treatment costs for patients and physicians who do and those who do not receive telehealth services under controlled circumstances. AHCPR-funded studies are presented as examples of methods of scientific investigation into the use and acceptance of computerized decision support and telehealth services.
Do not assume symptoms indicate failure of anti-tumor necrosis factor therapy in Crohn's disease.

It is a challenge to monitor patients with Crohn's disease who remain symptomatic despite anti–tumor necrosis factor therapy. Clinicians must use a systematic approach for each patient and obtain objective evidence about disease activity and response to therapy. Alternate etiologies for symptoms should be sought and treated, if found. Active Crohn's disease despite therapy requires reassessment and adjustments to management plans.
The role of C5a and antibody in the release of heparan sulfate from endothelial cells

The activation of endothelial cells is thought to contribute to the host response to infection and to the pathogenesis of autoimmune disease. It was recently shown that antibody and complement can activate endothelial cells leading to cleavage and release of heparan sulfate from the cells. We show here that release of heparan sulfate from endothelial cells is mediated by antibody and the complement fragment C5a and that assembly of the membrane attack complex and lysis of endothelial cells is not necessarily involved. These data suggest that the generation of C5a in conditions such as autoimmunity and infection in which anti-endothelial cell antibodies may also be present, might amplify tissue injury by a novel mechanism involving endothelial cell activation and loss of heparan sulfate mediated by antibody and C5a.
Residential Load Control: Distributed Scheduling and Convergence With Lost AMI Messages

This paper deals with load control in a multiple-residence setup. The utility company adopts a cost function representing the cost of providing energy to end-users. Each residential end-user has a base load, two types of adjustable loads, and possibly a storage device. The first load type must consume a specified amount of energy over the scheduling horizon, but the consumption can be adjusted across different slots. The second type does not entail a total energy requirement, but operation away from a user-specified level results in user dissatisfaction. The research issue amounts to minimizing the electricity provider cost plus the total user dissatisfaction, subject to the individual constraints of the loads. The problem can be solved by a distributed subgradient method. The utility company and the end-users exchange information through the Advanced Metering Infrastructure (AMI)-a two-way communication network-in order to converge to the optimal amount of electricity production and the optimal power consumption schedule. The algorithm finds near-optimal schedules even when AMI messages are lost, which can happen in the presence of malfunctions or noise in the communications network. The algorithm amounts to a subgradient iteration with outdated Lagrange multipliers, for which convergence results of wide scope are established.
Bibliography of Editions and Translations in Progress

In this issue, as in previous issues of the bibliography, onjy first entries carry the complete information on a project. All subsequent entries carry a cross-reference to the original entry together with the latest estimated date of completion. Projects for which directors fail to provide current information are labeled "no information available." When this failure occurs two years in succession, then entries carry the notation "second and final notice: no information available," and entries are eliminated from the bibliography. Readers wishing to order offprints of the bibliography may do so by sending one dollar to the Medieval Text Association, Baruch College of the City University of New York, 17 Lexington Avenue, New York, N.Y. 10010. And those wishing to list an entry may write for a questionnaire to the same address.
Exogenous Glucagon-Like Peptide-1 for Hyperglycemia in Critically Ill Patients

OBJECTIVE:To review literature evaluating the safety and efficacy of exogenous glucagon-like peptide-1 (GLP-1) for hyperglycemia in critically ill patients.DATA SOURCES:PubMed was queried (inception to September 3, 2011), using the search term glucagon-like peptide-1. The search was limited to studies published in English and conducted in humans. Regular and late-breaking abstracts from the American Diabetes Association Scientific Sessions in 2009 and 2010 were also searched using the same search term.STUDY SELECTION AND DATA EXTRACTION:All abstracts were screened for eligibility, which consisted of studies reporting the effects of intravenous GLP-1 administration on glycemic control in critically ill patients. Data extracted from eligible trials included study and population characteristics, measures of glycemic efficacy, and safety.DATA SYNTHESIS:Our search resulted in the identification of 2105 potentially relevant articles; of those, 7 were reviewed. All included publications evaluated the use of intr...
Progression of Glomerular and Tubular Disease in Pediatrics

Chronic kidney disease may be stimulated by many different etiologies, but its progression involves a common, yet complex, series of events that lead to the replacement of normal tissue with scar. These events include altered physiology within the kidney leading to abnormal hemodynamics, chronic hypoxia, inflammation, cellular dysfunction, and activation of fibrogenic biochemical pathways. The end result is the replacement of normal structures with extracellular matrix. Treatments presently are focused on delaying or preventing such progression, and are largely nonspecific. In pediatrics, such therapy is complicated further by pathophysiological issues that render children a unique population.
Short consensus repeat-3 domain of recombinant decay-accelerating factor is recognized by Escherichia coli recombinant Dr adhesin in a model of a cell-cell interaction

A bacterial pathogen that is important in both urinary tract and intestinal infections is Escherichia coli which expresses Dr or related adhesins. In this report, we present a model for testing cell-cell interaction, using both molecularly characterized laboratory cells that express recombinant molecules of human decay-accelerating factor (DAF), and recombinant bacterial Dr colonization factors. Dr adhesin ligand was identified as DAF (CD55), a membrane protein that protects autologous tissues from damage due to the complement system. Structure-function studies mapped the adhesin-binding site on the DAF molecule. A single-point substitution in the third short consensus repeat domain, Ser165 to Leu, corresponding to the Dra to Drb allelic polymorphism, caused complete abolition of adhesin binding to DAF.
Damped torsional oscillator model for polymer molecules

Abstract : An alternative model to the Rouse-Bueche (RB) theory of viscoelasticity is presented, in which the segments are torsional oscillators consisting of two or three backbone links, and the damping is due to hindered internal rotation (DTO model). The mathematical treatment of these two models is essentially identical, but the physical interpretation of the constants used is very different. The DTO model has previously been applied by one of us to the interpretation of viscoelastic data. It is applied to the interpretation of dielectric loss data. It is shown that dielectric measurements in dilute solution should very readily discriminate between the two approaches. Finally it is shown that the relaxation time computed from the DTO model is in very close agreement with published NMR data on poly(propylene) oxide 2025, whereas the RB relaxation time is 1000 times shorter than the experimental result. The postulates of the DTO model appear to be confirmed for this low molecular weight polymer. (Author)
Multiphysics model of a rat ventricular myocyte: A voltage-clamp study

The objective of this study is to develop a comprehensive model of the electromechanical behavior of the rat ventricular myocyte to investigate the various factors influencing its contractile response. Here, we couple a model of C a2 + dynamics described in our previous work, with a well-known model of contractile mechanics developed by Rice, Wang, Bers and de Tombe to develop a composite multiphysics model of excitation-contraction coupling. This comprehensive cell model is studied under voltage clamp (VC) conditions, since it allows to focus our study on the elaborate C a2 + signaling system that controls the contractile mechanism. We examine the role of various factors influencing cellular contractile response. In particular, direct factors such as the amount of activator C a2 + available to trigger contraction and the type of mechanical load applied (resulting in isosarcometric, isometric or unloaded contraction) are investigated. We also study the impact of temperature (22 to 38°C) on myofilament contractile response. The critical role of myofilament C a2 + sensitivity in modulating developed force is likewise studied, as is the indirect coupling of intracellular contractile mechanism with the plasma membrane via the N a+ /C a2 + exchanger (NCX). Finally, we demonstrate a key linear relationship between the rate of contraction and relaxation, which is shown here to be intrinsically coupled over the full range of physiological perturbations. Extensive testing of the composite model elucidates the importance of various direct and indirect modulatory influences on cellular twitch response with wide agreement with measured data on all accounts. Thus, the model provides mechanistic insights into whole-cell responses to a wide variety of testing approaches used in studies of cardiac myofilament contractility that have appeared in the literature over the past several decades.
Convergence of bladder and colon sensory innervation occurs at the primary afferent level

Abstract Dichotomizing afferents are individual dorsal root ganglion (DRG) neurons that innervate two distinct structures thereby providing a form of afferent convergence that may be involved in pelvic organ cross-sensitization. To determine the distribution of dichotomizing afferents supplying the distal colon and bladder of the Sprague–Dawley rat and the C57Bl/6 mouse, we performed concurrent retrograde labeling of urinary bladder and distal colon afferents using cholera toxin subunit B (CTB) fluorescent conjugates. Animals were perfused 4–5 days after sub-serosal organ injections, and the T10-S2 DRG were removed, sectioned, and analyzed using confocal microscopy. In the rat, CTB-positive afferents retrogradely labeled from the bladder were nearly three times more numerous than those labeled from the distal colon, while in the mouse, each organ was equally represented. In both species, the majority of colon and bladder afferents projected from lumbosacral (LS) ganglia and secondarily from thoracolumbar (TL) ganglia. In the rat, 17% of the total CTB-positive neurons were retrogradely labeled from both organs with 11% localized in TL, 6% in LS, and 0.8% in thoracic (TH) ganglia. In the mouse, 21% of the total CTB-positive neurons were dually-labeled with 12% localized in LS, 4% in TH, and 4% in TL ganglia. These findings support the existence of dichotomizing pelvic afferents, which provide a pre-existing neuronal substrate for possible immediate and maintained pelvic organ cross-sensitization and ultimately may play a role in the overlap of pelvic pain disorders.
Physiological and pharmacological properties of GABA-ergic gain modulation of canine ventral respiratory group (VRG) neurons

In vivo local application of the selective GABAA receptor antagonist bicuculline methochloride (BIC) to respiratory neurons in the caudal VRG of dogs produces a profound increase in their discharge frequency (Fn) pattern. The resulting Fn pattern is an amplified replica on the underlying control Fn pattern even when the pattern is reflexly altered, for example by lung inflation, or enhanced by changes in chemodrive [1]. These results suggested the presence of a tonic GABAergic gain modulation (GM) that normally attenuates the pattern to typically less than 50% of the Fn unblocked pattern. This multiplicative process can be modeled as: Fout = (1-α)*Fin, where Fout and Fin are the instantaneous Fns in the presence and absence of GABAergic inhibition, respectively, and α is the relative magnitude of tonic inhibition. The pharmacology of this mechanism is unusual in that picrotoxin, a noncompetitive GABAA receptor antagonist, does not produce GM, but is able to block the silent phase inhibition [2]. Also, recent in vitro studies have shown that the methyl derivatives of bicuculline block spike afterhyperpolarizations (AHPs) mediated by small conductance Ca2+ activated K+ channels (SK) [3]. The main objective of this study was to compare the in vivo effects of BIC with those of the SK channel blocker apamin on endogenously- (spontaneous) and exogenously-induced neuronal activities to discern the mechanism for BIC effects. Multibarrel micropipettes were used to record single unit activity from cVRG neurons in decerebrate dogs before and during picoejection of agonists and antagonists. Cycle-triggered histograms were used to quantify the Fn patterns and to determine the drug-induced changes in the gain and offset of the spontaneous Fn patterns. For the exogenous aspect of the study, the net increase in Fn due to repeated short duration picoejections of the glutamate receptor agonist, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), was quantified before and during locally induced antagonism of 1) GABAA receptors by BIC or 2) SK channels by apamin. BICm and apamin produced similar marked increases in gain, but different offsets. During maximum SK channel block with apamin, BICm produced an additional 112 ± 22% increase in peak Fn. Conversely, apamin produced an additional 176 ± 74% increase in peak Fn during the maximum BICm-induced response. The net AMPA-induced increases in Fn were not significantly altered by BIC, but were amplified in accordance with the gain increase produced by apamin block of AHPs. These results suggest that the BIC-sensitive GM of canine cVRG neurons is not due to a nonspecific block of AHPs, but is due to a GABAergic mechanism that modulates endogenously-, but not exogenously-induced activity. GABAergic GM, acting possibly via a shunting inhibition, may be functionally isolated from the soma/spike initiation zone to allow multiple nonrespiratory behaviors to be expressed by the same neurons, while providing adaptive respiratory gain control.
A mathematical model to determine viscoelastic behavior of in vivo primate brain

Determination of mechanical properties of the constituents of the head is very essential for the construction of various theoretical and experimental head injury models. This paper represents a mathematical mode1 for the evaluation of viscoelastic behavior of in viva primate brain. From a theoretical mechanics point of view, the problem being considered is that of the steady state response characteristics of a solid sphere of linear viscoelastic material whose mating surface with the rigid container is free from shear stresses. The external load is taken to be a local radial harmonic excitation. First. the response of the elastic material is determined; later the elastic response solution is converted to viscoelastic response solution through the use of the correspondence principle applicable to steady state oscillations. The paper is concluded with a discussion ot a method which enables the determination of the complex dynamic shear modulus of in uiuo primate brain. VULNERABILITY of the human head and the resulting fatalities from various injuries to the head is a well-established fact. The gravity of the situation has attracted many investigators from both experimental and theoretical fields of physical sciences. Previous research to give a proper description of the head injury has been either on determination of mechanical properties of the constituents of the head or on analyses of various theoretical head injury models. While investigations on these two categories are numerous, only a few representative ones will be mentioned here.
Endogenous production of lipoic acid is essential for mouse development.

α-Lipoic acid (LA) is a cofactor for mitochondrial α-ketoacid dehydrogenase complexes and is one of the most potent, natural antioxidants. Reduction of oxidative stress by LA supplementation has been demonstrated in patients with diabetic neuropathy and in animal models. To determine how normal development or pathological conditions are affected by genetic alterations in the ability of mammalian cells to synthesize LA and whether dietary LA can circumvent its endogenous absence, we have generated mice deficient in lipoic acid synthase (Lias). Mice heterozygous for disruption of the Lias gene develop normally, and their plasma levels of thiobarbituric acid-reactive substances do not differ from those of wild-type mice. However, the heterozygotes have significantly reduced erythrocyte glutathione levels, indicating that their endogenous antioxidant capacity is lower than those of wild-type mice. Homozygous embryos lacking Lias appear healthy at the blastocyst stage, but their development is retarded globally by 7.5 days postcoitum (dpc), and all the null embryos die before 9.5 dpc. Supplementing the diet of heterozygous mothers with LA (1.65 g/kg of body weight) during pregnancy fails to prevent the prenatal deaths of homozygous embryos. Thus, endogenous LA synthesis is essential for developmental survival and cannot be replaced by LA in maternal tissues and blood.
Issues in Genetic Testing

“Issues in Genetic Testing” was the theme for the Eighth Clinical Chemistry Forum of the American Association for Clinical Chemistry. The 2-day meeting was held in Arlington, Virginia, on November 3 and 4, 1998, and was jointly sponsored on this occasion by the Association for Molecular Pathology. Manuscripts of five of the meeting presentations have already been published in their entirety (1)(2)(3)(4)(5). The following is a summary of the remaining papers presented at the meeting. The opening presentation by Bradley W. Popovich , PhD, Director, DNA Diagnostic Laboratory, and Director, Clinical Genetic Services Laboratory, Oregon Health Sciences University, set the background for the conference by describing the evolution of DNA diagnostic testing. DNA tests generally are extremely accurate, minimally invasive, and cost-effective. Many hundreds of genetic conditions are already diagnosed through DNA testing. The number and variety of genetic tests will expand rapidly as an outgrowth of the Human Genome Project. ### differences between genetic and traditional laboratory tests Those who provide genetic counseling need to understand that DNA tests often require biological specimens from both the patient and other biological relatives, which clearly differentiates genetic testing from other tests. The information gained from DNA testing will not only be used by the physician to manage the patient’s treatment or care, but also has implications for other family members. Genetic tests can detect a predisposition to a disease, a condition that may or may not occur. Other genetic tests detect presymptomatic disease, a condition that is already present but whose symptoms have not yet developed. Three methods predominate genetic testing: Southern blot analysis, PCR, and DNA sequencing. Southern blot analysis has been used since the early 1980s, but it is extremely labor-intensive and the turnaround time is ∼1 to 2 weeks. The cost is between $250 and $500 per test. …
A Silicon, Carbon and Deuterium NMR Investigation of Molecular Templating in Amorphous Silicas

The precise pore sizes defined by crystalline zeolite lattices have led to intensive research on zeolite membranes. Unfortunately zeolites have proven to be extremely difficult to prepare in a defect-free thin film form needed for membrane flux and selectivity. We introduce tetrapropylammonium TPA (a structure directing agent for zeolite ZSM-5) into a silica sol and exploit the development of high solvation stresses to create templated amorphous silicas with pore apertures comparable in size to those of ZSM-5. {sup 29}Si and {sup 2}H NMR experiments were performed to evaluate the efficacy of our templating approach. The {sup 29}Si NMR spectrum of the silica matrix was observed by an intermolecular cross-polarization experiment between the {sup 1}H nuclei of TPA and the {sup 29}Si nuclei in the silica matrix. The efficiency of the cross-polarization interaction was used to investigate the degree to which the matrix formed a tight cage surrounding the template molecule. Normally prepared xerogel materials exhibited only weak interactions between the two sets of nuclei. Drying under reduced pressure, where solvation stresses are maximized, resulted in significantly increased interactions. Analogous materials were prepared using fully deuterated TPA. The {sup 2}H NMR wideline spectra consisted of a partially narrowed resonance, corresponding to template molecules which were undergoing restricted rotational motion, and an isotropically narrowed resonance, corresponding to molecules which were undergoing rapid rotational motion. The number of isotropically rotating template molecules decreased for specimens dried under reduced pressure, consistent with improved templating of amorphous silica by TPA.
Nationwide survey of US integrated 6-year cardiothoracic surgical residents.

Objective Integrated 6-year cardiothoracic surgical residency programs have recently been implemented in the United States. We report the results of the first published nationwide survey assessing the motivations, satisfaction, and ambitions of integrated 6-year residents. Methods A 63-question web-based survey was distributed to 83 residents enrolled in 21 Accreditation Council for Graduate Medical Education–accredited integrated 6-year programs in November 2013. There was an outstanding 69% response rate. Results The median age of integrated 6-year residents was 29 years with women comprising 24%. A clear majority had faculty mentorship (95%) and significant clinical exposure in medical school. Focused (100%) and abbreviated (74%) training curricula were identified as the top advantages of integrated 6-year programs; the format itself was a significant factor (46%) in career choice. Most integrated 6-year residents (95%) were satisfied with their program; 80.7% were satisfied with their operative experience thus far. Career plans skewed toward adult cardiac surgery (67%), followed by pediatric cardiac (24%) and general thoracic (9%) surgery; 49% were not particularly concerned about future employment, with 65% foreseeing an increase in opportunities. Specialized training (eg, aortic, heart failure, minimally invasive, congenital) was anticipated by 77%. Most integrated 6-year residents envision an academic career (94.7%). Conclusions This survey takes an important snapshot of the nascent integrated 6-year format. Mentorship and intense clinical exposure are critical in attracting applicants. Purported advantages of the format are holding true among integrated 6-year residents, with the majority satisfied with their programs. These early data indicate that this format holds significant promise in attracting and retaining highly qualified trainees to academic cardiothoracic surgery.
Optimal beamforming in ultrasound using the ideal observer

Beamforming of received pulse-echo data generally involves the compression of signals from multiple channels within an aperture. This compression is irreversible, and therefore allows the possibility that information relevant for performing a diagnostic task is irretrievably lost. The purpose of this study was to evaluate information transfer in beamforming using a previously developed ideal observer model to quantify diagnostic information relevant to performing a task. We describe an elaborated statistical model of image formation for fixed-focus transmission and single-channel reception within a moving aperture, and we use this model on a panel of tasks related to breast sonography to evaluate receive-beamforming approaches that optimize the transfer of information. Under the assumption that acquisition noise is well described as an additive wide-band Gaussian white-noise process, we show that signal compression across receive-aperture channels after a 2-D matched-filtering operation results in no loss of diagnostic information. Across tasks, the matched-filter beamformer results in more information than standard delay-and-sum beamforming in the subsequent radio-frequency signal by a factor of two. We also show that for this matched filter, 68% of the information gain can be attributed to the phase of the matched-filter and 21% can be attributed to the amplitude. A 1-D matched filtering along axial lines shows no advantage over delay-andsum, suggesting an important role for incorporating correlations across different aperture windows in beamforming. We also show that a post-compression processing before the computation of an envelope is necessary to pass the diagnostic information in the beamformed radio-frequency signal to the final envelope image.
Covalent Attachment and Derivatization of Poly(l-lysine) Monolayers on Gold Surfaces As Characterized by Polarization−Modulation FT-IR Spectroscopy

A monolayer of poly(l-lysine) (PL) is attached covalently via amide bonds to an alkanethiol self-assembled monolayer (SAM) on a gold surface. The amide bond is formed in two steps: the terminal carboxylic acid groups of an 11-mercaptoundecanoic acid (MUA) SAM are first activated to the N-hydroxysulfosuccinimide (NHSS) ester, followed by reaction of this MUA-NHSS ester monolayer with the amino groups of PL to create multiple amide bond linkages to the surface. The reactivity and packing density of the MUA-NHSS esters are investigated in detail by reacting these intermediates with ammonia (NH3). In the NH3 experiments, approximately 50% of the carboxylic acids in the MUA monolayer are converted to amides during the first cycle of this two-step surface reaction. This reaction yield of 50% is limited by the steric packing of the NHSS ester intermediate. However, after three cycles of MUA activation to the NHSS ester and reaction with NH3, nearly all of the MUA molecules (∼80%) are converted to amides. Polari...
Hepatitis A in Internationally Adopted Children: Screening for Acute and Previous Infections

OBJECTIVE The goal was to determine the prevalence of acute hepatitis A virus (HAV) infection and immunity among internationally adopted children. METHODS Children seen at the International Adoption Center between September 25, 2006, and September 30, 2008, and were screened for HAV within 4 months after their arrival in the United States were eligible for the study. The age- and country-specific prevalence of acute HAV infection and immunity were determined. RESULTS Overall, 288 children underwent HAV serological testing. Of the 279 with total HAV serological results, 29% had positive findings. Immunity varied according to region and country. The prevalence was lowest among children born in Asia/Pacific Rim region (17%) and highest among children born in Africa (72%). Only 13% of children <2 years of age were immune, compared with 80% of children 12 to 17 years of age (P = .002). Increasing age and birth region were associated independently with immunity. Positive HAV immunoglobulin M test results were found for 3 (1%) of 270 children; all were without symptoms. Their ages were 18, 27, and 41 months, and they were born in Kazakhstan, Russia, and the Latin America/Caribbean region, respectively. The father of 1 child developed HAV infection after arriving home. CONCLUSIONS HAV immunity among internationally adopted children varied according to age and country of origin; 1% had acute infections. HAV screening is useful for determination of the need for HAV immunization and for prevention of transmission to family members and close contacts.
Pseudo-obstruction in children: transplant or wait?

See article on page 570 With advances in immunosuppression intestinal transplantation has emerged as a viable option for patients with chronic intestinal failure and life threatening complications. With a one year graft survival rate of around 60% over the past few years, the current situation compares favourably with the pre-1990 results when 30% survival rates were achieved (data from the Intestinal Transplant Registry: www.lhsc.on.ca/itr). At the 7th Meeting of the European Intestinal Transplantation Study Group (Brussels, 1998), one year survival rates up to 80–90% were reported by some very experienced centres. In children, chronic intestinal pseudo-obstruction is often a primary disorder, either congenital or acquired. Secondary pseudo-obstruction is related to various systemic diseases and is more common in older patients. According to the pathological findings, the primary disease is classified as neuropathic, myopathic, or idiopathic if no specific pattern is recognised. The disease always involves the small bowel and may occur in any other (or all) regions of the digestive tract. …
Evaluation of cefoxitin disk diffusion breakpoint for detection of methicillin resistance in Staphylococcus pseudintermedius isolates from dogs

Cefoxitin disk diffusion susceptibility testing is a recommended screening method for the detection of methicillin resistance in human isolates of Staphylococcus aureus and coagulase-negative staphylococci. A retrospective analysis of 1,146 clinical isolates of Staphylococcus pseudintermedius from dogs was conducted to determine if screening by the cefoxitin disk method can be similarly useful with S. pseudintermedius. The distribution of cefoxitin growth inhibition zone diameters within this collection was bimodal and correlated well with the results of methicillin resistance gene (mecA) detection by polymerase chain reaction. Of the isolates, 5% had discordant results and, when retested, 84% of these were in agreement. While a greater diversity of isolates and interlaboratory comparisons must be tested, the current study suggests that an epidemiological breakpoint (of approximately ≤30 mm = resistant; ≥31 = susceptible) can be established to predict methicillin resistance in S. pseudintermedius.
End-Stage Renal Disease and Its Treatment in Latin America in the Twenty-First Century

The Latin American Society of Nephrology and Arterial Hypertension's Dialysis and Transplant Registry was chartered in 1991. It collects information on ESRD and its treatment in 20 countries of the region. The prevalence of patients on renal replacement therapy (RRT) increased from 129 pmp in 1992 to 447 pmp in 2004; in 2004, 56% of the patients were on hemodialysis, 23% on peritoneal dialysis, and 21% had a functioning kidney graft. The highest rates of prevalence were reported in Puerto Rico (1027 pmp), Chile (686 pmp), and Uruguay (683 pmp). Hemodialysis was widely used, except in El Salvador, Mexico, Guatemala, Nicaragua, and the Dominican Republic, where peritoneal dialysis predominated. Incidence rate increased from 27.8 pmp to 147 pmp in the same period of observation; the lowest rate was reported in Guatemala (11.4 pmp) and the highest in Puerto Rico (337.4 pmp). Diabetes mellitus was the leading cause of renal failure in incident patients; the highest rates were reported in Puerto Rico (62.2%) and Mexico (60%). Forty-four percent of the incident population were older than 65 years. Access to renal replacement therapy was universal in Argentina, Brazil, Chile, Cuba, Puerto Rico, Uruguay, and Venezuela, while was restricted in other countries. Main causes of death in dialysis were cardiovascular (44%) and infectious disease (26%). The rate of renal transplantation increased from 3.7 pmp in 1987 to 14.5 in 2004; fifty-three percent of the organs came from cadavers. Overall, donation rate was 5.9 pmp. In conclusion, the prevalence and incidence rates have increased over the years, and diabetes mellitus has emerged as the leading cause of kidney disease in the region. Although the rate of kidney transplantation has increased, the number remains insufficient to match the growing demand. The implementation of renal health programs in the region is urgently needed.
On completeness of feature spaces in blind steganalysis

Blind steganalyzers can be used for many diverse applications in steganography that go well beyond a mere detection of stego content. A blind steganalyzer can also be used for constructing targeted attacks or as an oracle for designing steganographic methods. The feature space itself provides a low-dimensional model of covers useful for benchmarking. These applications require the feature space to be complete in the sense that the features fully characterize the space of covers. Incomplete feature sets may skew benchmarking scores and lead to poor steganalysis. As a simple test of completeness, we propose a general approach for constructing steganographic methods that approximately preserve the whole feature vector and thus become practically undetectable by any steganalyzer that uses the same feature set. We demonstrate the plausibility of this approach, which we call the Feature Correction Method (FCM) by constructing the FCM for a 274-dimensional feature set from a state-of-the-art blind steganalyzer for JPEG images.
Three-dimensional model of cardiac electromechanics: cell to organ

We describe a new computational model that integrates the cellular biophysics of ventricular myocytes into structurally detailed three-dimensional models of the ventricular walls during the whole cardiac cycle. The new model is suitable for investigating hypotheses regarding excitation-contraction coupling in the intact heart.
Raising the Bar for Nonobviousness: An Empirical Study of Federal Circuit Case Law Following KSR

In KSR International Co. v. Teleflex Inc., the Supreme Court rejected the “rigid” application of the Federal Circuit’s “teaching, suggestion, motivation” test for obviousness. Despite the readily-apparent importance of this decision, it was hard to gauge the extent to which it would affect outcomes of obviousness decisions at the Federal Circuit. This paper reports an empirical study of all Federal Circuit decisions on obviousness in the two and a half years following KSR that documents a remarkable shift in the Federal Circuit’s willingness to uphold findings of obvious below. The Federal Circuit is now much less likely to reverse a lower-tribunal finding that a patent is obvious than a finding that a patent is nonobvious. During the two and a half year post-KSR period studied, the Federal Circuit did not reverse a single lower-tribunal determination of obvious. Further, obvious findings below were affirmed in 81.08% of all decisions. Nonobvious findings below, by contrast, were affirmed just 52.50% of the time. These and other findings are reported in detail, and are compared to the results of empirical studies of obviousness cases at the Federal Circuit reported prior to the KSR decision.
Reconstruction for stochastic 3-D signals with symmetric statistics in noise: Electron microscopy of virus particles

Cryo electron microscopy leads to 3-D image reconstruction problems. The data is one projection of each of many different instances of the object. When the object has symmetry and is also heterogeneous, it is natural to describe the object as stochastic with symmetrical statistics. This paper describes methods for incorporating the symmetry into expectation-maximization algorithms for the maximum likelihood solution of the reconstruction problem.
Determination of 10 elements in canned luncheon meat by microwave digestion-ICP-MS

Objective Inductively coupled plasma mass spectrometry technology was used to establish a method for determination of 10 elements in canned luncheon meat. Methods The samples were soaked in the mixture of nitric acid and hydrogen peroxide,and treated eith microwave digestion,the 10 elements,Pb,Cd,Hg,Cr,Cu,Zn,As,Se,Be,Tl,in the canned luncheon meat were simultaneously determined by inductively coupled plasma mass spectrometry. By using6 Li,72Ge,115 In,209Bi as the internal standard elements to eliminate matrix interference,to optimize instrumental parameters,and to select the best isotope to eliminate the interference of mass spectrometry. Results The correlation coefficient of standard curve of each element was above 0. 999 0,the detection limit was between 0. 000 4 mg / kg and 0. 004 8 mg / kg,the precision of this method was0. 58%- 7. 09%,and the standard addition rate was 93. 3%- 104. 6%. Standard substance test results of scallop and shell,GBW 10024( GBS- 15),was correspond to the reference values. To detect 10 different brands of canned luncheon meat,the results were satisfactory. Conclusion The method has advantages of good precision and accuracy,simpleness and rapidness,high sensitivity,and low detection limit,is a good method for the simultaneous determination of elements in the same food.
Research on Maximum Benefit Problem in a MapReduce Cluster

MapReduce is one of the most popular parallel systems for big-data analysis.Many companies have built their MapReduce clusters to provide computing services to users.Users can submit their deadline-constraint MapReduce jobs to the cluster.If the jobs are finished before their deadlines,the company can get some benefits.For this application scenario,the maximum benefit problem in a MapReduce cluster is firstly presented in this paper.To solve this problem effectively,a sequence-based task scheduling strategy(SEQ strategy for short)is proposed,and we prove the advantages of SEQ strategy for the deadline-constraint job processing.Based on SEQ strategy,a novel Algorithm for Maximum Benefit,AMB,is proposed.AMB can efficiently determine the acceptable jobs and provide the effective execution strategy which can maximize the benefit.Besides,for the exceptions(e.g.node failure)in practical applications,a timeouthandling method is proposed,which can further improve the practicality of the algorithm.At last,the effectiveness of the proposed algorithm is verified through plenty of experiments.
Fate of the autograft and homograft following Ross aortic valve replacement: reoperative frequency, outcome, and management.

BACKGROUND AND AIM OF THE STUDY The optimal hemodynamic performance and potential for growth of the pulmonary autograft has led to expanded indications for the Ross aortic valve replacement (AVR) procedure in some centers. The authors' institutional mid-term experience was reviewed to assess autograft and homograft hemodynamics, growth profile of the autograft, and reoperative frequency following Ross AVR. METHODS Between June 1993 and June 2005, 167 consecutive patients (mean age 24.9 +/- 15.5 years; range: 1 month to 61 years) underwent Ross AVR: 48% of patients were aged < 19 years. Additional procedures (n = 78) were performed in 55 patients (33%) at the time of the Ross procedure. In total, 151 patients had isolated aortic valve disease and 16 pediatric patients had more complex, multi-level left ventricular outflow tract obstruction. RESULTS There were two early deaths (1.2%) and one late death (0.6%) over a mean follow up of 5.1 +/- 3.0 years (range: 1 month to 11 years). Actuarial survival at 10 years was 98%. In pediatric patients with Konno procedure (n = 16), the pulmonary autograft mean annulus diameter increased from 10.2 to 19.9 mm. Twelve patients underwent 12 reoperations without mortality for autograft insufficiency or an ascending aortic aneurysm at a median interval of 5 years (range: 2 to 8 years): aortic annuloplasty and ascending aorta replacement (n = 4), composite aortic root replacement (n = 7), and repair of left ventricular pseudoaneurysm (n = 1). Freedom from replacement of the pulmonary autograft was 96% at 10 years. Five of the 164 surviving patients (3%) developed significant obstruction of the pulmonary homograft and required conduit replacement at a median of four years. CONCLUSION The Ross AVR can be performed with good mid-term results, including the pediatric age group. The potential for development of significant autograft insufficiency and homograft stenosis warrants annual follow up through the intermediate and late terms.