cssi/SciSciGPT-SciSciNet huggingface dataset:
The Effect of Early Feeding on the Development of Obesity

Early influences associated with adult obesity include overfeeding leading to fat cell hyperplasia, inactivity, and faulty mechanisms of control of food intake. The first year of life is critical for the intiation of these influences; thus we need to reevaluate some of the approaches to infant feeding. Excessive weight gains in infants must be taken seriously. This article reviews related literature and makes recommendations for preventing early obesity.
Visualization for knowledge discovery

Although the fields of data visualization and automated knowledge discovery (AKD) share many goals, workers in each field have been reluctant to adopt the tools and methods of the other field. Many AKD researchers discourage the use of visualization tools because they believe that dependence on human steering will impede the development of numerical or analytical descriptions of complex data. Many visualization researchers are concerned that their present platforms are being pushed to the limits of their performance by the most advanced visualization techniques and are therefore unwilling to incur the perceived overhead of having a database system mediate access to the data. We argue that these attitudes are somewhat short-sighted and that the techniques of these two communities are complementary. We discuss a specific visualization system that we have developed and describe the obstacles that must be overcome in integrating it into an AKD system. © 1992 John Wiley & Sons, Inc.
The effect of graded, single doses of busulfan on murine erythropoiesis.

SummaryThe effect of busulfan on murine erythropoiesis was studied following doses ranging from 10 to 100 mg/kg. The degree of depression of erythropoiesis was directly proportional to the dose of busulfan, as measured by hematocrit changes or by uptake of radioactive iron by spleen and marrow. The pattern of postbusulfan erythropoiesis was different from that seen after sublethal doses of whole body irradiation in some respects in that an abortive wave of erythropoiesis occurred in both marrow and spleen prior to onset of a more substantially sustained erythropoietic recovery. The pattern was like that following radiation in that the degree of reduction of erythropoiesis was directly related to dose as was the interval of time prior to onset of final recovery. In the spleen, this interval was 1 day per 20 mg/kg and in the marrow 0.5 days per 20 mg/kg.
Association of the serotonin transporter gene with sudden infant death syndrome: A haplotype analysis

Serotonergic receptor binding in the arcuate nucleus, n. raphe obscurus, and other medullary regions is decreased in sudden infant death syndrome (SIDS) cases. Further, an insertion/deletion polymorphism in the promoter region of the serotonin transporter protein (5-HTT) gene has recently been associated with risk of SIDS. This polymorphism differentially regulates 5-HTT expression, with the long allele (L), the SIDS-associated allele, being a more effective promoter than the short allele (S). To further elucidate the role of the 5-HTT gene in SIDS, we investigated the 5-HTT intron 2 polymorphism, which also differentially regulates 5-HTT expression with the 12 repeat allele being the more effective promoter. In a cohort of 90 SIDS cases (44 African-American and 46 Caucasian) and gender/ethnicity-matched controls, significant positive associations were found between SIDS and the intron 2 genotype distribution (P-value = 0.041) among African-American SIDS vs. African-American controls, specifically with the 12/12 genotype (P-value = 0.03), and with the 12 repeat allele (P-value=0.018). The frequency of the 12/12 genotype and 12-repeat allele was significantly different (P < 0.001) between the African-American and Caucasian SIDS cases. Furthermore, the promoter and intron 2 loci were in significant linkage disequilibrium, and the L-12 haplotype was significantly associated with SIDS in the African-American (P = 0.002) but not Caucasian (P = 0.117) subgroups. These results indicate a relationship between SIDS and the 12-repeat allele of the intron 2 variable number tandem repeat of the 5-HTT gene in African-Americans, and a significant role of the haplotype containing the 12-repeat allele and the promoter L-allele in defining SIDS risk in African-Americans. These data, if confirmed in larger studies, may begin to explain the differences in SIDS incidence by ethnicity, suggest a role for levels of 5-HTT expression in generation of SIDS susceptibility, and provide an important tool for identifying at-risk individuals and estimating the risk of recurrence. © 2003 Wiley-Liss, Inc.
Spontaneous regression of a hepatoma with ring calcification

The authors report a 74-year-old man with chronic hepatitis C-related cirrhosis and end-stage renal disease undergoing maintenance haemodialysis who was diagnosed with hepatoma. The hepatoma spontaneously regressed with significantly decreased serum alpha-fetoprotein level without any treatment during the subsequent 4-year follow-up period. However, recurrent hepatomas over bilateral hepatic lobes were evident thereafter, and the patient died later due to hepatic failure. Hepatoma with ring calcification is extremely rare and considered poor differentiation with high risk for recurrence. Spontaneous regression of hepatoma is also rare, while spontaneous regression occurring in a hepatoma with ring calcification is never reported. The definite mechanisms causing spontaneous regression of hepatomas remain unclear, but an immune response toward hepatoma induced by alpha-fetoprotein might play an important role.
Thermodynamic mechanism and consequences of the polyproline II (PII) structural bias in the denatured states of proteins.

A quantitative characterization of the structure and energy of the denatured states of proteins represents the cornerstone to a molecular-level understanding of both protein stability and fold specificity. Recent studies have revealed a significant bias in unstructured peptides toward the polyproline II (PII) conformation, even when no prolines are present in the sequence. This indicates that the PII conformation is a dominant component of the denatured states of proteins, although a quantitative description of the component enthalpy and entropy functions associated with this conformation (i.e., the thermodynamic mechanism) has thus far proven elusive. An experimental system has been designed that, when analyzed with high-precision isothermal titration calorimetry, provides direct access to the residue-specific thermodynamics of the PII structure formation in disordered proteins and peptides. Here, it is shown that the PII bias is driven by a favorable and significant enthalpy (Δh) of −1.7 kcal mol-1 resi...
Scientific discovery and topological transitions in collaboration networks

Abstract We analyze the advent and development of eight scientific fields from their inception to maturity and map the evolution of their networks of collaboration over time, measured in terms of co-authorship of scientific papers. We show that as a field develops it undergoes a topological transition in its collaboration structure between a small disconnected graph to a much larger network where a giant connected component of collaboration appears. As a result, the number of edges and nodes in the largest component undergoes a transition between a small fraction of the total to a majority of all occurrences. These results relate to many qualitative observations of the evolution of technology and discussions of the “structure of scientific revolutions”. We analyze this qualitative change in network topology in terms of several quantitative graph theoretical measures, such as density, diameter, and relative size of the network's largest component. To analyze examples of scientific discovery we built databases of scientific publications based on keyword and citation searches, for eight fields, spanning experimental and theoretical science, across areas as diverse as physics, biomedical sciences, and materials science. Each of the databases was vetted by field experts and is the result of a bibliometric search constructed to maximize coverage, while minimizing the occurrence of spurious records. In this way we built databases of publications and authors for superstring theory, cosmic strings and other topological defects, cosmological inflation, carbon nanotubes, quantum computing and computation, prions and scrapie, and H5N1 influenza. We also built a database for a classical example of “pathological” science, namely cold fusion. All these fields also vary in size and in their temporal patterns of development, with some showing explosive growth from an original identifiable discovery (e.g. carbon nanotubes) while others are characterized by a slow process of development (e.g. quantum computers and computation). We show that regardless of the detailed nature of their developmental paths, the process of scientific discovery and the rearrangement of the collaboration structure of emergent fields is characterized by a number of universal features, suggesting that the process of discovery and initial formation of a scientific field, characterized by the moments of discovery, invention and subsequent transition into “normal science” may be understood in general terms, as a process of cognitive and social unification out of many initially separate efforts. Pathological fields, seemingly, never undergo this transition, despite hundreds of publications and the involvement of many authors.
Coming to Terms with a Consensual Definition of Child Maltreatment

This study addresses the critical need to clarify current definitions of child maltreatment by identifying the extent to which consensus exists and highlighting those areas in which key decision makers disagree as to what affects an abuse determination. Participants (N = 323) were mental health, legal, and medical professionals; teachers; parents; and adult non-parents. Respondents agreed that actual physical or psychological harm to the child, whether the act is sexual in nature, seriousness and frequency of the act, and an intent to harm the child are key factors. The groups began to diverge on their evaluations of the degree to which intent should be factored into such a decision. Suggestions for future research aimed at developing more consistent legal and practice standards are presented.
Effect of Using Sugar or Starch in the Diet on Biological Responses in the Chick to Autoclaving Hexane Extracted Soybean Meal

Abstract INTRODUCTION NUMEROUS studies showing improvement of raw soybean meal by autoclaving have been reported and the relation of this improvement to protein utilization, trypsin inhibition and pancreatic secretion has been investigated. The influence of variations in composition of the basal diet, aside from protein and amino acid levels, on response to autoclaving raw soybean meal has not been thoroughly investigated. Bray (1964) reported that a diet with unheated soybean meal for laying hens gave egg production results considerably lower than the results reported by Saxena et al. (1963), who also used unheated soybean meal as the dietary protein. Aside from the soybean meal component of the diet, two other components were notably different: (1) starch was used by Bray (1964), whereas Saxena et al. (1963) used glucose; and (2) no supplementary methionine was used by Bray (1964) and 0.5% was added to the diet used by Saxena et al. (1963)… .
A semi-fragile watermarking system for MPEG video authentication

Video authentication is expected to prove the integrity of the content. Common authentication techniques do not allow any form of manipulation, thus making it impractical for some applications such as transcoding. In this paper, we shall propose an authentication scheme which can survive the bit-rate-conversion transcoding methods by using public, imperceptible semi-fragile watermark. Nowadays, videos are only available in compressed format in many applications. We will focus on the authentication of MPEG video. We will first provide a new classification of video tampering methods. Based on that, we shall propose our own authentication system. The proposed approach has a good locality corresponding to MPEG structure.
Implications de la thrombose in situ et de l’embolisation distale durant les interventions endoluminales sur l’artère fémorale superficielle

Introduction Le traitement endovasculaire des lesions occlusives de l’artere femorale superficielle (AFS) est commun, mais l’incidence et les consequences de la thrombose in situ (TIS) et de l’embolisation distale (ED) n’ont pas ete bien definis. L’objectif de cette etude etait d’examiner l’impact de la TIS et de l’ED sur les resultats a long terme des interventions sur l’AFS. Methode Une base de donnees sur les patients ayant beneficie d’un traitement endovasculaire au niveau de l’AFS a ete realise. Les patients ayant developpe soit une TIS traitee par agents lytiques pharmacomecaniques ou une ED ont ete selectionnes et compares aux patients n’ayant pas presente ce type de complication (groupe controle). Des analyses de survie selon Kaplan-Meier ont ete realisees pour analyser la survenue des evenements au cours du temps, avec une periode de suivi de deux ans. L’analyse des facteurs de risques a ete realisee a l’aide d’un modele de Cox pour les variables dependant du temps. Resultats 818 membres inferieurs ont beneficie d’un traitement endovasculaire pour une maladie occlusive symptomatique de l’AFS (59% pour claudication et 41% pour douleur au repos et perte tissulaire). Dans le groupe controle, 69% ont beneficie d’une angioplastie, 16% ont beneficie d’une stenting primaire, et 15% ont beneficie d’une therapie par laser/atherectomie directionnelle. Dans le groupe TIS, ces chiffres etaient de 41%, 28%, et 31% respectivement, alors que dans le groupe ED, ils etaient de 35%, 32%, et 33% respectivement. Au total, 3.5% des patients ont presente une TIS (tous traites par therapie lytique) et 3.8% une ED (68% traites de facon percutanee et le reste par embolectomie chirurgicale). Les femmes avaient plus de chance de presenter l’un ou l’autre des evenements. En comparaison au groupe controle, seulement un tiers des patients presentant une ED ont eu une angioplastie primaire, alors que les autres ont beneficie d’un stenting primaire ou un traitement par laser/atherectomie directionnelle. Il n’y avait pas de difference entre le groupe controle et le groupe ED en terme de permeabilites primaire, primaires assistees ou secondaire. L’ED etait associe a un taux de sauvetage de membre significativement plus bas (87 ± 2% vs. 68 ± 8%, pour les groupes controle vs. ED, p p p p p Conclusion La survenue d’une ED durant les interventions sur l’AFS est associee a une augmentation du taux de perte de membre, et ce independamment du lit d’aval preoperatoire et de l’intervention qui s’ensuit alors que l’utilisation d’une therapie lytique pharmacomecanique pour TIS est associee a une diminution du taux de permeabilite mais des taux inchanges de sauvetage de membre et de recidive des symptomes.
Nearest-Neighbor Mapping of Finite Element Graphs onto Processor Meshes

The processor allocation problem is addressed in the context of the parallelization of a finite element modeling program on a processor mesh. A heuristic two-step, graph-based mapping scheme with polynomial-time complexity is developed: 1) initial generation of a graph partition for nearest-neighbor mapping of the finite element graph onto the processor graph, and, 2) a heuristic boundary refinement procedure to incrementally alter the initial partition for improved load balancing among the processors. The effectiveness of the approach is gaged both by estimation using a model with empirically determined parameters, as well as implementation and experimental measurement on a 16 node hypercube parallel computer.
SU-E-T-41: Analysis of GI Dose Variability Due to Intrafraction Setup Variance.

Purpose: Proton SBRT (stereotactic body radiation therapy) can be an effective modality for treatment of gastrointestinal tumors, but limited in practice due to sensitivity with respect to variation in the RPL (radiological path length). Small, intrafractional shifts in patient anatomy can lead to significant changes in the dose distribution. This study describes a tool designed to visualize uncertainties in radiological depth in patient CT's and aid in treatment plan design. Methods: This project utilizes the Shadie toolkit, a GPU-based framework that allows for real-time interactive calculations for volume visualization. Current SBRT simulation practice consists of a serial CT acquisition for the assessment of inter- and intra-fractional motion utilizing patient specific immobilization systems. Shadie was used to visualize potential uncertainties, including RPL variance and changes in gastric content. Input for this procedure consisted of two patient CT sets, contours of the desired organ, and a pre-calculated dose. In this study, we performed rigid registrations between sets of 4DCT's obtained from a patient with varying setup conditions. Custom visualizations are written by the user in Shadie, permitting one to create color-coded displays derived from a calculation along each ray. Results: Serial CT data acquired on subsequent days was analyzed for variation inmore » RPB and gastric content. Specific shaders were created to visualize clinically relevant features, including RPL (radiological path length) integrated up to organs of interest. Using pre-calculated dose distributions and utilizing segmentation masks as additional input allowed us to further refine the display output from Shadie and create tools suitable for clinical usage. Conclusion: We have demonstrated a method to visualize potential uncertainty for intrafractional proton radiotherapy. We believe this software could prove a useful tool to guide those looking to design treatment plans least insensitive to motion for patients undergoing proton SBRT in the GI tract.« less
A Bayesian prediction of multiple-look identification performance from one-look data: The effect of unequal prior probabilities*

Bayes’s theorem had accurately predicted multiple-look visual identification performance from one-look data in two previous studies when the prior probabilities of the visual stimuli were equal. In this study, prior probabilities were manipulated to determine whether these values were important in determining agreement between man and statistical man. The prior probabilities of the stimuli, four gap orientations in Landolt rings, were .7, .1, .1, and .1 for four Ss and .3, .3, .3, and .1 for three Ss. One-look data were used to predict two-look and four-look performance. In the 7-1-1-1 condition, the empirical percent correct increased as a function of repeated observations for the rare stimuli, but not for the high-probability stimuli. In the 3-3-3-1 condition, Ss improved over repeated observations for both types of stimuli. Predictions of multiple-look performance under unequal prior probability conditions in this study were less accurate than those under equal prior probability conditions in previous studies. Three possible determinants of this difference were discussed.
An octave bandwidth electromagnetic band gap (EBG) structure

This paper presents a way in which a broadband EBG structure can be formed by stacking uniform EBG (electromagnetic band gap) structures. The design is validated by using it with a broadband monopole antenna. The paper shows the applications of stacked EBG structure. The performance of the antenna with the stacked EBG is compared with that of a uniform EBG.
Nasopharyngeal Radium Irradiation: The Washington County, Maryland, Study:

Abstract Although there have been many studies of cancer risk associated with a variety of x-ray treatments for benign conditions of the head and neck, little is known about the possible long-term health consequences of nasopharyngeal radium irradiation. This treatment results in minimal radiation exposure to the thyroid gland, which is the focus of much of the research regarding other head and neck irradiation. With nasopharyngeal radiation, on the other hand, exposure to the pituitary gland and the nasopharynx in the area immediately adjacent to the application site may have been substantial. In 1975 a follow-up study was undertaken in Washington County, Maryland, of 2925 persons who were treated at the Health Department's Clinic for the Prevention of Deafness in Children between 1943 and 1960. Of these, 904 persons had been treated with nasopharyngeal radium. After an average of 24 years of follow-up, an excess risk from brain cancer was suggested on the basis of three cases of cancer occurring in the treated group and none occurring in those who were not treated. This finding could have resulted by chance. Other results were consistent with a potential pituitary effect of radiation, but interpretation is limited by the absence of clinical and laboratory data. The history of the study is reported along with an overview of study methods and results.(Otolaryngol Head Neck Surg 1996;115:409-14.)>
Testing of Impact Limiters for Transportation Cask Design

‘Soft Impact Limiters’ such as polyurethane foams and aluminum honeycombs are being studied to assist the Sandia National Lbiatory's Transportation Base Technology Program. The aim of this research is to study the mechanical behavior of these materials, which are being used as impact absorbers in nuclear waste transportation containers. A series of tests were performed along various loading paths using an Instron, servo-controlled, multi-axial loading machine and Soiltest triaxial testing apparatus. Static tests included uniaxial tension, uniaxial compression, triaxial compression, hydrostatic compression and fracture toughness testing. The purpose of using different loading paths was to generate an extensive test data which is being used to develop constitutive models for these materials, under a separate research program. Dynamic tests were conducted at strain rates of 100 strains/sec., to generate experimental data relevant to accident situations. These tests were conducted on an instrumented Charpy impact testing apparatus. Results of these tests were subsequently used to conduct scale-model tests of transportation casks of different industrial designers. Different densities of Polyurethane foams, aluminum honeycombs, and corrugated aluminum honeycombs were tested in different orientations. The paper discusses the experimental program, instrumentation and test results for the nuclear waste transportation industry and other potential applications.
Liability Risks for After‐Hours Use of Public School Property to Reduce Obesity: A 50‐State Survey

BACKGROUND: One way to address childhood obesity is to create outlets for children to engage in physical activity. Schools are well equipped to provide an active environment. However, some school boards and administrators are concerned about liability risks. This study describes the legal rules applicable to potential claims against public schools during recreational use of school grounds and facilities. METHODS: Using traditional legal methods including the use of legal databases and treatises, the legal rules from 50 states were surveyed to determine what type of liability schools face when opening their grounds for after-school recreational use. RESULTS: Schools would, at most, be held to a reasonable standard of care, under which a person would be found liable if he did not act prudently in a given set of circumstances. This standard is no more onerous than that applied to most activities in the United States. Schools in many states, including California, also receive the benefit of governmental immunity. Furthermore, 21 states have recreational use statutes, which result in more lenient liability rules for injuries during recreational use of school facilities. CONCLUSIONS: Public schools in most states can be subject to liability in certain cases arising out of recreational use of their facilities. However, schools have important defenses. In combination with empirical research about liability in other contexts, this survey suggests that liability risks are unlikely to justify the denial of recreational access to children who are at risk of obesity. Language: en
The Andes: personal reflections on cultural change, 1977–2010

As my jet glided in for its landing in Lima, Peru, in the summer of 1977, I reviewed my papers and looked out of the window. Beneath the fog, the tan desert merged with numberless tan houses, and t...
Do higher gasoline taxes save lives

Abstract This study presents panel-based evidence on the overall traffic fatality consequences of recent changes in state gasoline taxes. Our results suggest that plausibly exogenous increases in state gasoline taxes are associated with fewer traffic fatalities.
Homophobia and Women's Sport: The Disempowerment of Athletes

Abstract One means to discredit women who engage in nontraditional gender role behavior, and thus challenge the prevailing patriarchal and heterosexist normative system, is to label them lesbian. This strategy is particularly effective given the homophobic attitudes so prevalent in society. Women athletes, in particular, are susceptible targets of lesbian labeling because of the historical linkage of masculinity with athleticism. The present study explores the dynamics of how this labeling of women athletes as lesbians and the accompanying homophobia fostering this label impact female intercollegiate athletes. Based on in-depth telephone interviews with 24 athletes, two major themes emerged: (1) a silence surrounding the issue of lesbianism in women's sport, and (2) athletes' internalization of societal stereotypes concerning lesbians and women athletes. These two processes disempower women athletes as they detract from the self-actualizing potential of sport participation. Paralleling other socially marg...
Dopaminergic modulation of corticosteroid responses to angiotensin II in man.

This study was designed to investigate dopaminergic mechanisms involved in the control of corticosteroid secretion in man. Plasma cortisol, corticosterone, 11-deoxycorticosterone, 18-hydroxycorticosterone (18-OHB), and aldosterone responses to graded doses of angiotensin II and ACTH were evaluated in six healthy male volunteers with and without treatment with the dopamine agonist bromocriptine (BEC). Angiotensin II infusion resulted in parallel responses of 18-OHB and aldosterone without affecting other precursors of the aldosterone biosynthetic pathway. BEC (2.5 mg tid for 6 days) markedly suppressed basal supine plasma 18-OHB levels without affecting basal levels of aldosterone. Basal supine plasma corticosterone levels were increased after BEC treatment. BEC treatment inhibited the 18-OHB and aldosterone responses to graded infusions of angiotensin II. Plasma 18-OHB responses to ACTH infusion were not altered by BEC treatment. Other factors known to affect aldosterone and 18-OHB secretion such as plasm...
Do Some Men Who Desire Sex Reassignment Have A Mental Disorder? Response to Lawrence (2011)

It is always an intellectual pleasure to be challenged by Anne Lawrence, because of her thorough scrutiny of logic and data in the course of scientific arguments. Yet, the title of Lawrence’s (2011) comment here, ‘‘Do Some Men Who Desire Sex Reassignment Have A Mental Disorder?’’, is misleading. Posed that way, the question yields trivial answers, because humans of almost any category include individuals with ‘‘a mental disorder,’’ provided the sample is large enough. As her comment shows,however, thequestionLawrencereallyaddresses isadifferent one, namely:‘‘Is the desire for sex reassignment in some men to be understood as a mental disorder in terms of a particular classification system of psychiatric conditions?’’ From a nosological perspective,‘‘sex reassignment’’is a treatment or management procedure, whereas psychiatric diagnosis classifies mental conditions; for the latter purpose, a procedural term is not appropriate nor is the term of a desire for such a procedure. Analogously, in somatic medicine, a malignant tumor is diagnosed as pathology whether or not the patient desires its surgical removal. Moreover, the nonhomosexual men who come to clinicians like myself with a stated desire for sex reassignment are very variable in their gender history and current psychological condition, especially in adolescence. By contrast, persons with gender identity variants (GIVs) of a degree that they meet DSM-IV criteriaforGender IdentityDisorder (GID)usually impressmeby the uniformity of their presentation relative to other conditions described in the DSM, and interclinican agreement tends to be high. (My use of the DSM-IV criteria here is merely for purposes of description and should not be taken as an indication that I have come to a definitive conclusion whether or not GIVs should be categorized as a mental disorder in DSM-5.) Thus, unlike Lawrence, I do not see the contemporary gender-identity construct as particularly‘‘abstract’’or‘‘impreciselydefined,’’and,basedonmy experience in developing a variety of psychological assessment instruments, I do not find its operationalization to be unusually difficult. For the main focus of this discussion, I will, therefore, assume that the section of the transgender spectrum, on which Lawrence focuses, comprises adult 46,XY persons with male-typical primary andsecondary somatic sex characteristicswho meetDSMIV criteria A, B, and C for GID, are sexually attracted to females, and desire hormonal and surgical sex reassignment from male to female (MtF). Note that this delineation is narrower than Lawrence’s,but ifweconsider includingamongthesementhosewho do not meet DSM-IV criteria for GID, Lawrences’s rationale becomes even more problematic. Now to Lawrence’s answer to the mental disorder question. The developmental sequence and related conclusions regarding psychopathology, as described by her for nonhomosexual MtF transsexuals, can be summarized as follows.
Purification and properties of rat liver adenine phosphoribosyltransferase.

Abstract The adenine phosphoribosyltransferase (AMP : pyrophosphate phosphoribosyltransferase, EC 2.4.2.7) of rat liver was purified to a specific activity of 1.1 μmol of AMP formed per min per mg. The enzyme activity is associated with an apparently homogeneous protein as shown by isoelectrofocusing, acrylamide gel electrophoresis, and N-terminal amino acid analysis (phenylalanine). The molecular weight of the enzyme was estimated to be approx. 20 000 by acrylamide gel electrophoresis in the presence of sodium dodecylsulfate and by sucrose density gradient zone sedimentation. The rat liver enzyme exhibited initial burst synthesis of AMP when 1-pyrophosphorylribose 5-phosphate was added. The 1-pyrophosphorylribose 5-phosphate initial-burst activity copurifies with the adenine phosphoribosyltransferase activity. A pH optimum of 10.0 was demonstrable for the adenine phosphoribosyltransferase. The initial-burst and steady-state phases of AMP synthesis catalyzed by highly purified rat liver adenine phosphoribosyltransferase have been partially characterized by the use of ligands which bind to sulfhydryl groups. Studies utilizing p -chloromercuribenzoate and HgCl 2 as inhibitors of AMP synthesis during the initial-burst and steady-state phases have revealed that sulfhydryl groups with different rates of ligand binding are present in the enzyme. The initial-burst phase was thereby delineated from the steady-state phase by use of these mercurial ligands. This delineation was also accomplished by titration with the Mg 2+ chelator, EDTA. The inhibitory effects of mercurials and EDTA were reversed by β-mercaptoethanol and excess Mg 2+ , respectively. Quantitative binding studies with 5,5′-dithiobis(2-nitrobenzoic acid) and p -chloromercuribenzoate yielded values of 3.65 and 3.6 mol of sulfhydryl per mol of enzyme, respectively. 3.3 mol of cysteic acid per mol of performic acid-oxidized enzyme were found by amino acid analysis.
In vivo phosphorylation of CFTR promotes formation of a nucleotide-binding domain heterodimer

The human ATP-binding cassette (ABC) protein CFTR (cystic fibrosis transmembrane conductance regulator) is a chloride channel, whose dysfunction causes cystic fibrosis. To gain structural insight into the dynamic interaction between CFTR's nucleotide-binding domains (NBDs) proposed to underlie channel gating, we introduced target cysteines into the NBDs, expressed the channels in Xenopus oocytes, and used in vivo sulfhydryl-specific crosslinking to directly examine the cysteines' proximity. We tested five cysteine pairs, each comprising one introduced cysteine in the NH2-terminal NBD1 and another in the COOH-terminal NBD2. Identification of crosslinked product was facilitated by co-expression of NH2-terminal and COOH-terminal CFTR half channels each containing one NBD. The COOH-terminal half channel lacked all native cysteines. None of CFTR's 18 native cysteines was found essential for wild type-like, phosphorylation- and ATP-dependent, channel gating. The observed crosslinks demonstrate that NBD1 and NBD2 interact in a head-to-tail configuration analogous to that in homodimeric crystal structures of nucleotide-bound prokaryotic NBDs. CFTR phosphorylation by PKA strongly promoted both crosslinking and opening of the split channels, firmly linking head-to-tail NBD1–NBD2 association to channel opening.
Surgical Treatment of Incyclotorsion After Macular Translocation

IntroductionThe purpose of this study was to review the incidence and management of strabismus after macular translocation surgery for severe age-related macular degeneration.MethodsPatients underg...
Functional implications of spontaneous sarcoplasmic reticulum Ca2+ release in the heart

The Cai oscillation generated by the sarcoplasmic reticulum in response to an action potential occurs relatively synchronously within and among cells. The sarcoplasmic reticulum can also generate spontaneous Cai oscillations (S-CaOs), ie, not triggered by sarcolemmal depolarisation. The local increase in Cai due to S-CaOs is equivalent to that induced by an action potential. Heterogeneity of diastolic Cai among cells within myocardial tissue caused by asynchronous S-CaOs leads to heterogeneous myofilament activation, the summation of which produces a Ca2+ dependent component to diastolic tone. The local increases in Cai due to S-CaOs also cause oscillatory sarcolemmal depolarisations due to Ca2+ modulation of the Na-Ca exchanger and of non-specific cation channels. When local S-CaOs within a myocardial cell is sufficiently synchronised the resultant depolarisation summates and can be sufficient to trigger a spontaneous action potential. Inhomogeneous levels of diastolic Cai among cells may lead to heterogeneity in cell coupling and thus may also affect the impulse conduction in myocardial tissue. The magnitude of the S-CaOs induced diastolic tonus and depolarisation varies with the extent to which S-CaOs are synchronised; partially synchronised S-CaOs following an action potential induced Ca2+ release produce an aftercontraction and afterdepolarisation. Inhomogeneity of diastolic sarcoplasmic reticulum Ca2+ loading and sarcomere lengths within individual cardiac cells due to S-CaOs leads to inhomogeneous systolic Cai levels and sarcomere inhomogeneities in response to a subsequent action potential, which compromise the systolic contraction amplitude. Heterogeneity of systolic Cai among cells due to diastolic S-CaOs also leads to heterogeneity of action potential repolarisation times, due to heterogeneous Cai modulation of the Na-Ca exchanger, the non-specific cation channel, the L type Ca2+ channel and, depending upon species, Ca2+ activated K+ channels. S-CaOs occurrence during a long action potential plateau may also modulate the removal of voltage inactivation of L type Ca2+ channels, and affects the likelihood of the occurrence of "early afterdepolarisations." Thus, as a single entity, S-CaOs may be implicated in diverse manifestation of heart failure--impaired systolic performance, increased diastolic tonus, and an increased probability for the occurrence of arrhythmias.
Quantitative risk assessment of microbial sampling effectiveness

Abstract Sampling as a means of assuring food safety can be analyzed by quantitative risk assessment. A computer simulation was performed in which liquid raw material with varying levels of contamination (−1 to −6 log CFU/ml) was converted into a food by a process that causes a mean log reduction of 5 log CFU/ml. Sampling before and after processing was simulated to determine if the food met the microbial quality standards of the product and to determine when sampling was more effective. Sampling the raw material was more useful than sampling the finished food product, because the levels of contamination were lower and harder to detect after processing. Sampling many batches of the product over time gave a clear idea of the contamination levels in the raw material. Sampling was least effective when contamination levels were moderate to low, though certain pathogens could still cause outbreaks of food-borne illness at these levels.
An adult case of canine neuronal ceroid-lipofuscinosis.

Intraneuronal accumulation of cytosomes with the fluorescent and tinctorial properties of ceroid-lipofuscin occurred in the C.N.S. of a fully matured dog with signs of slowly progressive cerebellar disease. Ultrastructural study revealed various membrane-bound inclusions in addition to typical lipofuscin granules. The clinicopathologic findings in this case were contrasted with those occurring in English Setters with juvenile neuronal ceroid-lipofuscinosis, and compared with those reported in Kufs' disease in man.
Novel algorithms reveal streptococcal transcriptomes and clues about undefined genes.

Bacteria–host interactions are dynamic processes, and understanding transcriptional responses that directly or indirectly regulate the expression of genes involved in initial infection stages would illuminate the molecular events that result in host colonization. We used oligonucleotide microarrays to monitor (in vitro) differential gene expression in group A streptococci during pharyngeal cell adherence, the first overt infection stage. We present neighbor clustering, a new computational method for further analyzing bacterial microarray data that combines two informative characteristics of bacterial genes that share common function or regulation: (1) similar gene expression profiles (i.e., co-expression); and (2) physical proximity of genes on the chromosome. This method identifies statistically significant clusters of co-expressed gene neighbors that potentially share common function or regulation by coupling statistically analyzed gene expression profiles with the chromosomal position of genes. We applied this method to our own data and to those of others, and we show that it identified a greater number of differentially expressed genes, facilitating the reconstruction of more multimeric proteins and complete metabolic pathways than would have been possible without its application. We assessed the biological significance of two identified genes by assaying deletion mutants for adherence in vitro and show that neighbor clustering indeed provides biologically relevant data. Neighbor clustering provides a more comprehensive view of the molecular responses of streptococci during pharyngeal cell adherence.
TH‐B‐T‐6E‐01: Monte Carlo Applications in Conformal, IMRT and 4D Clinical Treatment Planning: Pitfalls and Triumphs

Due to its ability to accurately model dose distributions for arbitrarily complex treatment delivery scenarios and patient geometries, it is highly probable that over the next few years the use of Monte Carlo in routine clinical planning will become substantially more widespread. Building on the discussion of the role of Monte Carlo in treatment head simulation (from the first course), this second Monte Carlo course will focus on patient planning applications. The goal of the course is to familiarize clinical medical physicists with the use of Monte Carlo in treatment planning, including advanced treatment techniques such as IMRT and motion compensated 4D treatment, and to discuss how Monte Carlo based planning differs from conventional algorithm based planning. We will demonstrate the utility of Monte Carlo with respect to improved dose calculation accuracy (versus conventional algorithms) in heterogeneous patient tissues, and illustrate how a properly benchmarked Monte Carlo system can play a unique role in the modeling of complex delivery procedures, such as IMRT. In particular, the ability to effectively model the dosimetric consequences of the detailed the multi‐leaf collimator(MLC) geometry with Monte Carlo will be demonstrated. Finally, we will show how Monte Carlo can be applied to compensate for organ motion in 4D treatment planning without an increase in computation time. In addition to illustrating the role of Monte Carlo in complex treatment planning, an important focus of this course will be to provide guidance to clinical physicists on practical issues associated with the implementation, verification and clinical use of Monte Carlo systems. Educational Objectives: 1. To familiarize clinical physicists with Monte Carlo applications for routine clinical treatment planning. 2. To understand the dosimetric influence of Monte Carlo in different anatomical sites and to become familiar with the potential clinical outcome benefits of Monte Carlo. 3. To understand some of the issues that clinical physicists face in the implementation and experimental verification of Monte Carlotreatment planning systems. 4. To understand the use, benefits and limitations of Monte Carlo for IMRT optimization and QA. 5. To become familiar with the role of Monte Carlo in motion compensated (4D) treatment planning.
On the behavior of separating equilibria of signaling games with a finite set of types as the set of types becomes dense in an interval

Abstract While signaling models with a continuum of types have well-determined (often unique) separating equilibria, models with a finite set of types do not. For signaling games, the following is proved: Suppose there is a sequence of finite sets of types, each set refining its predecessor and the limit set dense in an interval. Then every sequence of separating equilibrium paths has a convergent subsequence, the limit of any convergent sequence is a separating equilibrium path of the limit game, and the convergence is uniform. If the limit game has a unique equilibrium path then every sequence converges to it.
Extension of the method of complex basis functions to molecular resonances

We consider the extension of the complex-coordinate technique to the problem of locating molecular resonances. We suggest a method which uses complex normalizable functions and which becomes equivalent to the usual dilatation transformation asymptotically, but is different for small values of the electronic coordinates. The technique is illustrated by application to the bound states of ${\mathrm{H}}_{2}^{+}$ and to a model nonspherical resonance problem.
Simulation of Capacitance-Voltage characteristics of Ultra-thin Metal-Oxide-Semiconductor Structures with Embedded Nanocrystals

This paper presents an approach to model quantum mechanical effects in solid-state devices such as Metal Oxide Semiconductor (MOS) capacitor with and without nanocrystal in the oxide at the device simulation level. This quantum-mechanical model is developed to understand finite inversion layer width and threshold voltage shift. It allows a consistent determination of the physical oxide thickness based on an agreement between the measured and modeled C-V curves. However, as for thinner oxides finite inversion layer width effects become more severe, quantum-mechanical model predicts higher threshold voltage than the classical model. The inversion-layer charge density and MOS capacitance in multidimensional MOS structures are simulated with various substrate doping profiles and gate bias voltages. The effectiveness of the QM correct method for modeling quantum effects in ultrathin oxide MOS structures is also investigated. The CV characteristic is used as a tool to compare results of the QM correction with that of the Schrodinger–Poisson (SP) solution and Classical solution The variation of (different parameters) for various doping profiles at different gate voltages is investigated.
Idazoxan down-regulates β-adrenoceptors on C6 glioma cells in vitro

Incubation of the C6 cells with 10 microM idazoxan (an alpha 2-adrenoceptor antagonist and putative antidepressant) for 5 days in vitro resulted in a 23% reduction of beta-adrenoceptor number and a 37% decrease in isoproterenol-induced cyclic AMP accumulation. In contrast, post-receptor stimulated cyclic AMP accumulation (by the use of forskolin or cholera toxin) was unaffected. The desensitization of the beta-adrenoceptor was accompanied by an increase in the KL/KH ratio for this receptor. Chronic in vitro treatment of C6 glioma cells with idazoxan did not significantly affect cholera or pertussis toxin catalyzed ribosylation of Gs and Gi/Go in these cells. Similarly, idazoxan did not alter either the basal levels of protein kinase C (PKC) alpha, or its cytoplasm to membrane translocation. These results suggest that idazoxan may have direct postsynaptic effects, the site of which may be at the level of receptor/G protein interaction.
Likely near-term solar-thermal water splitting technologies

Abstract Thermodynamic and materials considerations were made for some two- and three-step thermochemical cycles to split water using solar-thermal processing. The direct thermolysis of water to produce H2 using solar-thermal processing is unlikely in the near term due to ultra-high-temperature requirements exceeding 3000 K and the need to separate H2 from O2 at these temperatures. However, several lower temperature ( K ) thermochemical cycles including ZnO/Zn, Mn2O3/MnO, substituted iron oxide, and the sulfur–iodine route (S–I) provide an opportunity for high-temperature solar-thermal development. Although zirconia-based materials are well suited for metal oxide routes in terms of chemical compatibility at these temperatures, thermal shock issues are a major concern for solar-thermal applications. Hence, efforts need to be directed towards methods for designing reactors to eliminate thermal shock (ZrO2 based) or that use graphite (very compatible in terms of temperature and thermal shock) with designs that prevent contact of chemical species with graphite materials at high temperatures. Fluid-wall reactor configurations where inert gases provide a blanket to protect the graphite wall appear promising in this regard, but their use will impact process efficiency. For the case of S–I up to 1800 K , silicon carbide appears to be a suitable material for the high-temperature H2SO4 dissociation. There is a need for a significant amount of work to be done in the area of high-temperature solar-thermal reactor engineering to develop thermochemical water splitting processes.