cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of Tamulamides A and B: Polyethers Isolated from the Marine Dinoflagellate Karenia brevis

Florida red tides occur as the result of blooms of the marine dinoflagellate Karenia brevis. K. brevis is known to produce several families of fused polyether ladder compounds. The most notable compounds are the brevetoxins, potent neurotoxins that activate mammalian sodium channels. Additional fused polyether ladder compounds produced by K. brevis include brevenal, brevisin, and hemibrevetoxin B, all with varying affinities for the same binding site on voltage-sensitive sodium channels. The structure elucidation and biological activity of two additional fused polyether ladder compounds containing seven fused ether rings will be described in this paper. Tamulamide A (MW = 638.30) and tamulamide B (MW = 624.29) were isolated from K. brevis cultures, and their structures elucidated using a combination of NMR spectroscopy and high-resolution mass spectrometry. Tamulamides A and B were both found to compete with tritiated brevetoxin-3 ([(3)H]-PbTx-3) for its binding site on rat brain synaptosomes. However, unlike the brevetoxins, tamulamides A and B showed no toxicity to fish at doses up to 200 nM and did not cause significant bronchoconstriction in sheep pulmonary assays.
An unexpectedly high excision capacity for mispaired 5-hydroxymethyluracil in human cell extracts.

The oxidation of thymine in DNA can generate a base pair between 5-hydroxymethyluracil (HmU) and adenine, whereas the oxidation and deamination of 5-methylcytosine (5mC) in DNA can generate a base pair between HmU and guanine. Using synthetic oligonucleotides containing HmU at a defined site, HmU-DNA glycosylase activities in HeLa cell and human fibroblast cell extracts have been observed. An HmU-DNA glycosylase activity that removes HmU mispaired with guanine has been measured. Surprisingly, the HmU:G excision activity is 60 times greater than the corresponding HmU:A activity, even though the expected rate of formation of the HmU:A base pair exceeds that of the HmU:G base pair by a factor of 107. The HmU:G mispair would arise from the 5mC:G base pair, and, if unrepaired, would give rise to a transition mutation. The observation of an unexpectedly high HmU:G glycosylase activity suggests that human cells may encounter the HmU:G mispair much more frequently than expected. The conversion of 5mC to HmU must be considered as a potential pathway for the generation of 5mC to T transition mutations, which are often found in human tumors.
Polymer Solid Acid Composite Membranes for Fuel‐Cell Applications

A systematic study of the conductivity of polyvinylidene fluoride (PVDF) and CsHSO4 composites, containing 0 to 100% CsHSO4, has been carried out. The polymer, with its good mechanical properties, served as a supporting matrix for the high proton conductivity inorganic phase. The conductivity of composites exhibited a sharp increase with temperature at 142°C, characteristic of the superprotonic phase transition of CsHSO4. At high temperature (160°C), the dependence of conductivity on vol % CsHSO4 was monotonic and revealed a percolation threshold of ~10 vol %. At low temperature (100°C), a maximum in the conductivity at ~80 vol % CsHSO4 was observed. Results of preliminary fuel cell measurements are presented.
A simplified chemical model for estimating the nonequilibrium radiant emission of CN /violet/ in shock-heated mixtures of CO sub 2 and N sub 2.

Chemical model for CN nonequilibrium radiant emission intensity profiles in shock heated mixture of N and carbon dioxide
Microscopic modelling of bulk and quantum-well GaAs-based semiconductor lasers

The dynamical behaviour of Fabry-Perot type semiconductor lasers is modelled, including the relevant many-body Coulomb effects of the excited carriers. Conditions are given under which a parametrization of the full model is possible, allowing simple analytic relations for local gain, refractive index and linewidth enhancement factor. The parameters of the simplified model are uniquely determined by the microscopic theory and have to be optimized for the respective operating conditions. The theory is evaluated for bulk and quantum-well GaAs active material and a variety of laser structures, including strongly and weakly index-guided structures, as well as purely guided single-and twin-stripe lasers.
Folate in tropical sprue.

Summary. Persons who acquire tropical sprue lose their ability to absorb folate from the diet. This is due to inability to hydrolyse polyglutamate forms in most cases and additionally to absorb monoglutamate folate in instances of severe mucosal damage. Neither the specific site of impaired deconjugation nor the acutal defect in the transport process are known. Malabsorption of folate results in a sequence of events similar to that which occurs when folate is deleted from the diet: prompt fall in serum concentration followed by development of megaloblastic changes in the bone marrow and eventually anaemia. Reduced tissue stores, if present due to inadequate intake or increased requirement, increases the rapidity of folate depletion. Prompt but partial response of the mucosal abnormality to treatment with folic acid indicates that once acquired, folate deficiency acts in some unexplained manner to perpetuate the intestinal lesion.
Identifying and Testing Models of Managerial Compensation

This article analyses the identification and empirical content of the pure moral hazard (PMH) and the hybrid moral hazard (HMH) principal–agent models. The PMH model has hidden actions, while the HMH model has hidden information in addition to hidden actions. In both models, agents are risk averse and principals are risk neutral. The article derives the equilibrium restrictions from the optimal contract and uses the restrictions to show that the models have empirical content. For any given risk-aversion parameter, the models' other parameters are non-parametrically point identified. The risk-aversion parameter—and hence the model—are, however, only partially identified. Management's ability to manipulate accounting reports arises endogenously within HMH models, but not in all versions of PMH models. We use our framework to investigate whether shareholders contract with management recognizing that accounting reports are susceptible to manipulation and, therefore, endogenous to the incentives offered to management. The data reject all models in which accounting reports are verifiable. Furthermore, the version of the PMH in which accounting reports can be manipulated is rejected if expected compensation is restricted to be positive.
Correlation of dynamic friction and the dislocation etch pit density surrounding annealed scratches in (1 1 1) p-type silicon

The dynamic friction coefficient between a 90° pyramid diamond and a (1 1 1) p-type silicon single crystal has been measured for linear, unidirectional scratches made in the [1 1 0] direction in laboratory air, deionized water and ethanol. The friction coefficient for grooves formed in air increased from 0,6 to 0.7 as the number of scratches increased, reaching a steady state value after ten scratches. The friction coefficient for grooves formed in deionized water and ethanol decreased from 0.7 to 0.5 and also reached a steady state value after ten scratches. Scanning electron microscopy showed that the groove morphology depended on the fluid in contact with the surface during the scratch test. The grooves formed after ten scratches were annealed to 750° C for 3600 sec and etch pits were measured as a function of distance from the groove wall. The etch pit density and their distance from the groove wall was related to the type of fluid used in the scratch test: the density was highest and the distance from the groove wall largest for the groove formed in air and lowest for the groove formed in ethanol. These results imply that the deformation mode and the magnitude of the residual stresses surrounding the groove depend on the enviromental conditions during the scratch test. The friction coefficient was found to vary linearly with the average etch pit density.
Insects in confined swine operations carry a large antibiotic resistant and potentially virulent enterococcal community

Extensive use of antibiotics as growth promoters in the livestock industry constitutes strong selection pressure for evolution and selection of antibiotic resistant bacterial strains. Unfortunately, the microbial ecology and spread of these bacteria in the agricultural, urban, and suburban environments are poorly understood. Insects such as house flies (Musca domestica) and German cockroaches (Blattella germanica) can move freely between animal waste and food and may play a significant role in the dissemination of antibiotic resistant bacteria within and between animal production farms and from farms to residential settings. Enterococci from the digestive tract of house flies (n = 162), and feces of German cockroaches (n = 83) and pigs (n = 119), collected from two commercial swine farms were isolated, quantified, identified, and screened for antibiotic resistance and virulence. The majority of samples (93.7%) were positive for enterococci with concentrations 4.2 ± 0.7 × 104 CFU/house fly, 5.5 ± 1.1 × 106 CFU/g of cockroach feces, and 3.2 ± 0.8 × 105 CFU/g of pig feces. Among all the identified isolates (n = 639) Enterococcus faecalis was the most common (55.5%), followed by E. hirae (24.9%), E. faecium (12.8%), and E. casseliflavus (6.7%). E. faecalis was most prevalent in house flies and cockroaches, and E. hirae was most common in pig feces. Our data showed that multi-drug (mainly tetracycline and erythromycin) resistant enterococci were common from all three sources and frequently carried antibiotic resistance genes including tet(M) and erm(B) and Tn916/1545 transposon family. E. faecalis frequently harbored virulence factors gelE, esp, and asa1. PFGE analysis of selected E. faecalis and E. faecium isolates demonstrated that cockroaches and house flies shared some of the same enterococcal clones that were detected in the swine manure indicating that insects acquired enterococci from swine manure. This study shows that house flies and German cockroaches in the confined swine production environment likely serve as vectors and/or reservoirs of antibiotic resistant and potentially virulent enterococci and consequently may play an important role in animal and public health.
Non-operative management of a rare diagnosis of splenic torsion in a child with a history of giant omphalocele: a case report and literature review

Background Splenic torsion is rare and as a result the appropriate management is unclear. While there has been a shift towards splenectomy and laparoscopic splenopexy, we present a successful case of non-operative management of splenic torsion in a patient with a history of a giant omphalocele.
Belief-bias and labor unions: The effect of strong attitudes on reasoning

This study compared three types of reasoning bias associated with strong belief: Judgement of plausibility, contrast effects, and social attribution. Respectively, these relate to bias in the perceived validity and extremity of statements and bias in causal interpretations of actions. Technical college students (N = 153) in two highly unionized communities completed one scale for each form of bias and a section of the IRC Union Attitude Scale which measured their attitude toward unions. Belief–bias was indicated across all three measures although there were differences in their salience. Social attribution was the strongest type of bias manifested (r = 0.58, p ⩽ 0.001) and contrast effects (r = 0.33, p ⩽ 0.001) were a second and third. The implications of these results are explored and future research directions in this new line of study are suggested.
Further evidence that the ribosomal 30S proteins S3, S5, S9, S11, S12, and S18 possess specific 16S RNA binding sites.

E. coli ribosomal 16S RNA preparted by an acetic acid-urea extraction technique individually binds, in addition to the seven established proteins, 6 new 30S ribosomal proteins (S3, S5, S9, S12, S18 and S11) (Hochkeppel et al., 1976). In this communication we demonstrate the site specificity of these proteins. Binding curves of the individual proteins with acetic acid-urea 16S RNA show that the binding of all six proteins to the RNA reaches a plateau at 0.3–0.97 copies per 16S RNA molecule. No significant binding of these proteins to classical phenol extracted 16S RNA is observed, with the exception of S13 which binds 0.2 copies of protein per molecule of 16S RNA. Specificity of binding of these proteins is also demonstrated in “chase” experiments. The site specificity of individual [3H]-labeled 30S proteins bound to 16S RNA is tested by the addition of non-radioactive 30S total protein to the reaction mixture.
Demo: Kahawai: high-quality mobile gaming using GPU offload

This paper presents Kahawai1, a system that provides high-quality gaming on mobile devices, such as tablets and smartphones, by offloading a portion of the GPU computation to server-side infrastructure. In contrast with previous thin-client approaches that require a server-side GPU to render the entire content, Kahawai uses collaborative rendering to combine the output of a mobile GPU and a server-side GPU into the displayed output. Compared to a thin client, collaborative rendering requires significantly less network bandwidth between the mobile device and the server to achieve the same visual quality and, unlike a thin client, collaborative rendering supports disconnected operation, allowing a user to play offline - albeit with reduced visual quality. Kahawai implements two separate techniques for collaborative rendering: (1) a mobile device can render each frame with reduced detail while a server sends a stream of per-frame differences to transform each frame into a high detail version, or (2) a mobile device can render a subset of the frames while a server provides the missing frames. Both techniques are compatible with the hardware-accelerated H.264 video decoders found on most modern mobile devices. We implemented a Kahawai prototype and integrated it with the idTech 4 open-source game engine, an advanced engine used by many commercial games. In our evaluation, we show that Kahawai can deliver gameplay at an acceptable frame rate, and achieve high visual quality using as little as one-sixth of the bandwidth of the conventional thin-client approach. Furthermore, a 50-person user study with our prototype shows that Kahawai can deliver the same gaming experience as a thin client under excellent network conditions.
Quantitative sequence-function relationships in proteins based on gene ontology

The relationship between divergence of amino-acid sequence and divergence of function among homologous proteins is complex. The assumption that homologs share function – the basis of transfer of annotations in databases – must therefore be regarded with caution. Here, we present a quantitative study of sequence and function divergence, based on the Gene Ontology classification of function. We determined the relationship between sequence divergence and function divergence in 6828 protein families from the PFAM database. Within families there is a broad range of sequence similarity from very closely related proteins – for instance, orthologs in different mammals – to very distantly-related proteins at the limit of reliable recognition of homology. We correlated the divergence in sequences determined from pairwise alignments, and the divergence in function determined by path lengths in the Gene Ontology graph, taking into account the fact that many proteins have multiple functions. Our results show that, among homologous proteins, the proportion of divergent functions decreases dramatically above a threshold of sequence similarity at about 50% residue identity. For proteins with more than 50% residue identity, transfer of annotation between homologs will lead to an erroneous attribution with a totally dissimilar function in fewer than 6% of cases. This means that for very similar proteins (about 50 % identical residues) the chance of completely incorrect annotation is low; however, because of the phenomenon of recruitment, it is still non-zero. Our results describe general features of the evolution of protein function, and serve as a guide to the reliability of annotation transfer, based on the closeness of the relationship between a new protein and its nearest annotated relative.
Ground- and excited-state spectral and redox properties of cadmium(II) texaphyrin

Cadmium texaphyrin, [(TXP)Cd] + , a representative of a new family of expanded porphyrins, has an absorption maximum around 760 nm in acetonitrile solution. The first excited triplet state, which is formed with a quantum yield of 0.9, is quenched by O 2 , via an energy-transfer process, and by aromatic amines, via an electron-transfer reaction. This latter process produces [(TXP)Cd] o , the neutral radical, as characterized by flash photolysis methods, with an overall quantum efficiency of about 60%. The potential of the texaphyrin family as photosensitizers for photodynamic therapy is highlighted.
Tight Binding Electronic Structure Calculations and Tight Binding Molecular Dynamics with Localized Orbitals

We describe in detail and extend our recent algorithm for tight binding total energy calculations and tight binding molecular dynamics, which scales quadratically with the size of the system for small systems and linearly for big systems. It is intrinsically parallel and gives excellent performance on parallel computers. The central quantity in this algorithm are the localized orbitals. We show in the context of various examples, that our localized orbital algorithm is not only fast, but gives us a better physical undersatnding than conventional extended orbitals and more flexibility in treating complicated geometries. The algorithm can also efficiently handle metallic systems and does not lead to unphysical distortions of the electronic density of states around the Fermi level.
A taxonomy of multicast protocols for Internet applications

The continuous growth in applications that require communications among a group of hosts or simultaneous dissemination of data to multiple sites on the Internet has led to considerable interest in multicast communication. These applications have different quality of service requirements such as deadlines to response time and tolerance to data loss. Internet multicast protocols provide a spectrum of services to cater for the needs of a wide array of multicast applications. The design alternatives of a multicast protocol for a particular application may lead to different performance characteristics, for example higher utilization of network bandwidth vs lower protocol processing requirements. Therefore a framework is required to various design choices available to design multicast protocols and evaluate the performance tradeoffs associated with these alternatives. Motivated by such a need and by the evolution of multicast applications over the Internet, this article presents a taxonomy of multicast protocols and a common framework to evaluate their performance.
Reliability improvement of paper feeder by the integrated robust design and control approach

A methodology for system reliability improvement is presented based on the integration of reliability modeling, robust design, and on-line monitoring and control techniques. Such method has been successfully applied for the quality improvement of a paper handling system.
Role of simvastatin and methyl-β-cyclodextin on inhibition of poliovirus infection

Cells exposed to simvastatin or to methyl-β-cyclodextrin show reduced poliovirus infection, without alteration in virus binding or on the kinetics of genome entry, suggesting that the steps which are altered are those post uncoating and genome entry. Reduction of infection by cyclodextrin is reversed by increasing MOI whereas that produced by simvastatin treatment is not, suggesting that the effects on infection are not due to a reduction in cholesterol. The differences in the characteristics of inhibition can be explained by the differential effects of the compounds. Cyclodextrin inhibits the store-operated calcium channels, suggesting that reduction in infection is through translational inhibition. Simvastatin produces vesicles from internal membranes which cannot sustain viral RNA synthesis, reducing infection through reduced transcription. The results indicate that the impact on viral infection by the cholesterol-modifying agents is due to the cellular changes produced rather than due to disruption of the cholesterol-rich domains.
The Ca2+-activated K+ channel KCa3.1 compartmentalizes in the immunological synapse of human T lymphocytes

T cell receptor engagement results in the reorganization of intracellular and membrane proteins at the T cell-antigen presenting cell interface forming the immunological synapse (IS), an event requ...
Dibromomethane and carbon monoxide in the rat : comparison of the cardiovascular and metabolic effects

The goals of this study were to examine the cardiovascular and metabolic responses to a dihalogenated methane and to compare them to inhaled CO. One group of male Sprague-Dawley rats received an i.p. injection of either 3 or 6 mmol kg−1 dibromomethane (DBM) diluted 1:3 with sesame oil. Measurements of carboxyhemoglobin (COHb), rectal body temperature (BT), heart rate, systolic blood pressure (BP) and blood glucose and lactate concentrations were made at times 0, 30, 60, 120, 240, 360, 480, 600, 720, 840, 1020, 1440 and 1680 min. A second group of rats received only sesame oil and was tested in the same manner. A third group of rats breathed 225 ppm CO for 120 min before being tested. Peak COHb levels were 16% 8 h after 3 mmol kg−1 DBM, 18% 12h after 6 mmol kg−1 DBM and 17% in the CO-exposed group. The sesame oil controls exhibited no elevation in COHb. The BT dropped by ca. 1°C in both the DBM- and CO-exposed rats, while there was no BT change in the sesame oil controls. The BT dropped by 1.0°C and 1.2°C after 6h in the 3 and 6 mmol kg−1 DBM groups, respectively, and by 0.9°C after 120 min in the CO-exposed group. The CO-exposed rats displayed a 12 mmHg decrease in systolic BP, while both doses of DBM failed to produce any significant BP change. The BP in the sesame oil controls remained constant. There were no significant changes in heart rate or in blood glucose or lactate in any of the experimental groups. The lack of a BP response in the DBM rats may be due to DBM interferring with the rat's normal response to CO, or to the effects of dissolved CO vs. COHb. Dibromomethane uptake results in the development of significant and prolonged COHb saturation, at a level similar to that resulting from inhalation of 225 ppm CO. Although BT regulation is impaired, DBM appears not to have significant effects on BP, heart rate or blood glucose and lactate concentrations.
Cascade: a universal programmer-assisted type qualifier inference tool

Type qualifier inference tools usually operate in batch mode and assume that the program must not be changed except to add the type qualifiers. In practice, programs must be changed to make them type-correct, and programmers must understand them. Cascade is an interactive type qualifier inference tool that is easy to implement and universal (i.e., it can work for any type qualifier system for which a checker is implemented). It shows that qualifier inference can achieve better results by involving programmers rather than relying solely on automation.
Growth Response of Loblolly Pine (Pinus taeda L.) 3–5 Years After Plantation Establishment Using Different Management Intensities

The upward trend of intensive management in Southern pine forests is expected to continue, both in area and intensity level. Much of the Mississippi Lower Coastal Plain (LCP) is managed intensively using some combination of mechanical site preparation, chemical site preparation, and herbaceous weed control (HWC). We studied pine growth response and competition control on loblolly pine (Pinus taeda L.) plantations 3–5 years following establishment using five combinations of chemical site preparation, mechanical site preparation, and HWC. Treatments were designated a priori as 1 (least intensive) through 5 (most intensive) largely on the basis of anticipated impact on the vegetation community. We measured pine height and diameter at breast height (dbh); woody stem density; hardwood basal area (BA); coverage of herbaceous plants, understory woody plants, and pine trees; and estimated differences in pine response using age-shift calculations at age 5. Pine height and dbh were correlated with treatment intensi...
Making a Beast With Green Backs: The Legal Battle Over Money in American Elections

An examination of the legal battle over Citizens United and its consequences for our electoral system.
Parental criminality and low self‐control: an examination of delinquency

Researchers have shown that parenting practices are important in self‐control theory. The purpose of the present study was to examine the link between parental low self‐control, low self‐control, and delinquency. Using a national probability sample and structural equation modeling, the present study showed that parental low self‐control has a link with child low self‐control and that low self‐control does have a link with delinquency. Another structural equation model showed that self‐control mediated the link between parental low self‐control and delinquency. The theoretical implications are discussed.
The adolescent behavior checklist: Normative data and sensitivity and specificity of a screening tool for diagnosable psychiatric disorders in adolescents with mental retardation and other developmental disabilities

Individuals with mental retardation are almost twice as likely to demonstrate severe behavioral problems or symptoms of mental illness as are nonmentally retarded individuals. At present, however, the ability to diagnose a mental disorder in an individual with mental retardation is difficult, and instruments are needed to help facilitate this process. The Adolescent Behavior Checklist was developed with this purpose in mind. This self-report scale is used to assess the likelihood that an adolescent with mild mental retardation or borderline intelligence has a diagnosable mental illness. The 86-item yes/no self-report scale renders scores on eight subscales derived from DSM III-R. The checklist has been found to have good criterion and congruent validity and good test-retest reliability. Data regarding interrater reliability and the sensitivity and specificity of the scale are presented, as are implications for future research.
Two stage coprocessing of coal with model and commingled waste plastics mixtures

Coprocessing of coal with waste plastics in two separate stages was investigated in order to tailor the reaction conditions and catalysts used in each stage for the materials present. In the first stage reaction, waste plastics were liquefied at 440°C (713 K) for 1 h with an initial H2 pressure of 2.8 MPa and a catalyst, either the zeolite HZSM-5 or one of two cracking catalysts, Low Alumina or Super Nova-D, which was used to break selectively the hydrocarbon chains in the waste polymer. In the second stage, coal was added and the reaction conditions were selected to maximize the coal conversion and hydrotreatment of the dissolving coal molecules. The solvent used in the second stage was the hexane soluble fraction from the first stage reaction. Most of the second stage reactions were performed at 400°C (673 K) for 30 min, with an initial H2 pressure of 5.6 MPa and a slurry-phase hydrotreating catalyst, either Mo naphthenate, Fe naphthenate, or a combination of the two, plus excess sulfur. Two types of waste plastics, a model mixture composed of 50% high density polyethylene (HDPE), 30% polyethylene terephthalate (PET), and 20% polystyrene (PS), and an actual mixture, composed primarily of HDPE and polypropylene (PP), were used. The catalysts chosen for the first stage reaction were found to have a significant effect on the quality of the hexane soluble liquids produced, and, hence, also affected the second stage processing. The second stage catalyst affected the overall product and boiling point distributions. Separation of the two reactions into two stages afforded the opportunity for selecting reaction conditions and catalysts to obtain a higher conversion and production of materials in the desired boiling point range than that available using single stage processing.
Establishing Validity and Reliability of a Health Belief Model and Acculturation Scale for Measuring Safe-Sex and Sexual Communication Behaviors Among African Immigrants for Protecting Against HIV/AIDS

The objective of the study was to develop a valid and reliable scale for measuring safer sex and sexual communication behaviors among African immigrants. A 68-item instrument based on Health Belief Model (HBM) and acculturation was validated. The test-retest reliability (n = 30) and internal consistency (n = 412) were also tested. A confirmatory factor analysis (CFA) using structural equation modeling (SEM) was used for establishing the construct validity of the instrument (n = 412). The Cronbach's alphas and test-retest reliability coefficients for all the subscales were found to be over.70. The results for CFA yielded acceptable factor loadings (.30) for the subscales and overall the model was a good fit. This instrument has acceptable validity and reliability and can be used for survey and intervention research in African immigrants.
Cloning, Expression, and Biochemical Characterization of Streptomyces rubellomurinus Genes Required for Biosynthesis of Antimalarial Compound FR900098

The antibiotics fosmidomycin and FR900098 are members of a unique class of phosphonic acid natural products that inhibit the nonmevalonate pathway for isoprenoid biosynthesis. Both are potent antibacterial and antimalarial compounds, but despite their efficacy, little is known regarding their biosynthesis. Here we report the identification of the Streptomyces rubellomurinus genes required for the biosynthesis of FR900098. Expression of these genes in Streptomyces lividans results in production of FR900098, demonstrating their role in synthesis of the antibiotic. Analysis of the putative gene products suggests that FR900098 is synthesized by metabolic reactions analogous to portions of the tricarboxylic acid cycle. These data greatly expand our knowledge of phosphonate biosynthesis and enable efforts to overproduce this highly useful therapeutic agent.
An Analysis of U.S. Civil Society

Dans son ouvrage The Changing and Unchanging Face of U.S. Civil Society l'A. propose une analyse institutionnelle de la societe civile americaine. Cinq composantes de la societe civile sont degagees: les associations volontaires; la diversite d'association; l'impact des technologies de transport et de communication; l'autonomie locale; la mediation. Cet article reprend une breve presentation de cette analyse
Finite element methods for the displacement obstacle problem of clamped plates

We study finite element methods for the displacement obstacle problem of clamped Kirchhoff plates. A unified convergence analysis is provided for C1 finite element methods, classical nonconforming finite element methods and C0 interior penalty methods. Under the condition that the obstacles are sufficiently smooth and that they are separated from each other and the zero displacement boundary constraint, we prove that the convergence in the energy norm is O(h) for convex domains.
Mammalian sexual differentiation: lessons from the spotted hyena

Female spotted hyenas (Crocuta crocuta) are the only female mammals that lack an external vaginal opening. Mating and birth take place through a urogenital canal that exits at the tip of a hypertrophied clitoris. This ‘masculine’ phenotype spurred a search for an alternate source of fetal androgens. Although androstenedione from the maternal ovary is readily metabolized to testosterone by the hyena placenta, formation of the penile clitoris and scrotum appear to be largely androgen independent. However, secretions from the fetal testes underlie sex differences in the genitalia and central nervous system that are essential for male reproduction. Naturally circulating androgens, acting prenatally, reduce reproductive success in adult female spotted hyenas. Effects on aggression and dominance might offset these reproductive ‘costs’ of female androgenization in utero.
“Setting the clock back to zero” property of a family of life distributions

Abstract We define, what we have called the “setting the clock back to zero” or an invariance property of a family of life distributions. This property ensures that the conditional distribution of the additional time of survival of a living organism or an industrial item, given that it has survived x 0 units, remains in the family. This concept generalizes the lack of memory property of the exponential distribution, for which the conditional distribution of additional survival time is exactly the same as the original distribution. It is shown that Krane's (1963) family of life distributions possesses this property. This family includes the exponential and Kodlin classes. The Gompertz and Pareto families are also shown to have this property. The advantage of having such a property appears in many epidemiological, biomedical and engineering investigations.
A review of research on bullying and peer victimization in school: An ecological system analysis☆

Abstract Bullying and peer victimization in school are serious concerns for students, parents, teachers, and school officials in the U.S. and around the world. This article reviews risk factors associated with bullying and peer victimization in school within the context of Bronfenbrenner's ecological framework. This review integrates empirical findings on the risk factors associated with bullying and peer victimization within the context of micro - (parent–youth relationships, inter-parental violence, relations with peers, school connectedness, and school environment), meso - (teacher involvement), exo - (exposure to media violence, neighborhood environment), macro - (cultural norms and beliefs, religious affiliation), and chrono system (changes in family structure) levels. Theories that explain the relationships between the risk factors and bullying behavior are also included. We then discuss the efficacy of the current bullying prevention and intervention programs, which is followed by directions for future research.
Developing and Validating the Classroom Literacy Environmental Profile (CLEP): A Tool for Examining the “Print Richness” of Early Childhood and Elementary Classrooms.

In this report, the development, field testing, and validation of the Classroom Literacy Environment Profile (CLEP) are described. In the first phase, characteristics of print-rich classroom environments were identified, defined, and organized into categories through a review of the literature, classroom observations, and teacher focus groups. In the second phase of the project, categories and themes interpreted from phase one data were used to write and review the initial items of the instrument. In phase three, generalizability evidence for the CLEP instrument was examined using a G or generalizability study. Classrooms and items evidenced large variance components indicating that the degree of implementation of print-rich classroom environments was reliably discriminated using the CLEP. Following the G study, three D or decision studies were conducted in which the numbers of raters and the number of rating occasions were varied to determine acceptable levels of generalizability and error. It is well-established and nearly accepted as axiomatic that environment plays a central role in learning and behavior — especially among young children in preschool, kindergarten, and school classrooms. Many early childhood and elementary teachers evidence intuitive concern for the effect of the classroom environment on children’s learning and behavior when they provide access to, design, arrange, and display various objects, artifacts, furnishing, etc., in their classrooms. And yet, as Roskos and Neuman (2001) remind us, teachers and school administrators need to understand at deeper
Theoretical and Technical Aspects of the Design of Ultrasonic Hyperthermia Equipment

Parallel to research and development work in other countries (Lele 1983; Hynynen et al. 1982), in 1980 the German Ministry for Research and Technology (BMFT) initiated a research and development on study local hyperthermia with ultrasonics of superficial and deep-located tumors. The two main objectives of the first phase of the study were: 1. Identification and evaluation of the primary physiological and technical parameters essential for optimizing ultrasonic equipment and treatment procedures, including therapeutic risks 2. Construction and assessment of an optimized ultrasonic facility (engineering model) for later clinical application
Modeling a scalable high-speed interconnect with stochastic Petri nets

This paper presents an approach to using Stochastic Petri nets to model large-scale concurrent systems, in our case, a scalable computer interconnect. We show how Stochastic Petri net models can exploit the symmetry of the system to construct a tractable, but approximate, analytic model, and that they can yield results very close to those of a detailed simulation model, with much less computational effort.
Application of enriched deontic legal relations: Federal Rules of Civil Procedure Rule 7(a), pleadings

Deontic LEGAL RELATIONS are quantified OBLIGATION or PERMISSION statements in the Logic of LEGAL RELATIONS. Such LEGAL RELATIONS stem from Hohfeld's right-duty-privilege-no-right set of fundamental legal conceptions. The four Hohfeldian roots are enriched by more detailed specification in terms of quantifier, deontic, action and temporal logics. The 1600 enriched deontic LEGAL RELATIONS defined in the Logic of LEGAL RELATIONS are both more specific and more discriminating than their Hohfeldian predecessors. A brief summary is presented of the 800 active enriched deontic LEGAL RELATIONS along with other parts of the LEGAL RELATIONS Language involved in the analysis of the important Rule 7(a) of the Federal Rules of Civic Procedure dealing with pleadings.
Characterizing the interaction between uranyl ion and soil fulvic acid using parallel factor analysis and a two-site fluorescence quenching model

Abstract In this study, a two-site fluorescence quenching data treatment was developed based on the Ryan–Weber model to investigate natural organic matter complexation with uranyl ion. Parameters for each ligand site including stability constant (log K ), ligand site concentration ( C L ) and residual fluorescence intensity ( I res ) were determined using this approach. Parallel factor (PARAFAC) analysis was used to obtain quantitative data for peaks from fluorescence excitation emission matrix (EEM) spectra. This model was tested using a Cu 2 + titration with a mixed system of tyrosine and tryptophan to simulate two ligands. Relatively good agreements with literature values (within 3.29% for log K values) indicated the validity of the model. The model was further applied in the complexation study between soil fulvic acid (SFA) and UO 2 2 + since two components were predicted using core consistency diagnoses (CORCONDIA) for our SFA sample. Results for 20 mg/L SFA at pH 3.50 for the peak at λ ex = 330 nm, λ em = 450 nm were log K = 4.49, C L = 5.05 μmol/L, and I res = 15.1 and for the peak at λ ex = 240 nm, λ em = 450 nm were log K = 4.56, C L = 4.56 μmol/L, and I res = 1.2.
Enhancement of photosynthesis in Sorghum bicolor by ultraviolet radiation

We assessed the influence of ultraviolet radiation (UV) on net photosynthetic CO 2 assimilation rate (P n ) in Sorghum bicolor, with particular attention to examining whether UV can enhance P n via direct absorption of UV and absorption of UV-induced blue fluorescence by photosynthetic pigments. A polychromatic UV response spectrum of leaves was constructed by measuring P n under different UV supplements using filters that had sharp transmission cut-offs from 280 to 382 nm, against a background of non-saturating visible light. When the abaxial surface was irradiated, P n averaged 4.6% higher with the UV supplement that cut-off UV at 311 nm, compared to lower and higher UV wavelength supplements. This former supplement differed from higher wavelength supplements by primarily providing more UV between 320 and 350 nm. To assess the possibility of direct absorption of UV by photosynthetic pigments, we measured the absorbance of extracted chlorophylls. Chlorophyll a had absorbance peaks at 340 and 389 nm that were 49 and 72% of that at the soret peak. Chlorophyll b had absorbance peaks at 315 and 346 nm that were both 35% of that at the soret peak. Since the epidermis transmits some UV, the strong UV absorbance of chlorophyll implies a potential role for irradiance beyond the bounds of the conventionally defined photosynthetically active radiation waveband (400-700 nm). To assess the role of absorption of UV-induced blue fluorescence, we measured the UV-induced fluorescence excitation and emission spectra of leaves. Abaxial excitation peaked at 328 nm, while emission peaked at 446 nm. In this analysis, we used our abaxial fluorescence excitation spectrum and the UV photosynthetic inhibition spectrum of Caldwell et al. (1986) to weight the UV irradiance with each cut-off filter, thereby estimating the potential contribution of UV-induced blue fluorescence to photosynthesis and the inhibitory effects of UV irradiance on photosynthesis, respectively. With a non-saturating visible background, we estimate that the absorption of UV-induced blue fluorescence and the direct absorption of UV by photosynthetic pigments maximally enhanced photosynthesis by about 1% each with the UV supplement that cut-off UV at 311 nm. We suggest that a portion of the incident UV on the S. bicolor leaves was used to drive photosynthesis.
Bivariate Analysis of DNA Content and Expression of Cyclin Proteins

Cyclins are key components of the cell cycle machinery. This unit describes techniques associated with measurement of these transiently expressed molecules and focusses on the combination of cell cycle analysis and expression of proliferation-associated proteins via immunocytochemically attached antibodies. Keywords: flow cytometry; cyclins; DNA content; cell cycle; proliferation-associated proteins Cyclins are key components of the cell cycle machinery
Purification and Molecular Characterization of the Tungsten-Containing Formaldehyde Ferredoxin Oxidoreductase from the Hyperthermophilic Archaeon Pyrococcus furiosus: the Third of a Putative Five-Member Tungstoenzyme Family

Pyrococcus furiosus is a hyperthermophilic archaeon which grows optimally near 100 degreesC by fermenting peptides and sugars to produce organic acids, CO2, and H2. Its growth requires tungsten, and two different tungsten-containing enzymes, aldehyde ferredoxin oxidoreductase (AOR) and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR), have been previously purified from P. furiosus. These two enzymes are thought to function in the metabolism of peptides and carbohydrates, respectively. A third type of tungsten-containing enzyme, formaldehyde ferredoxin oxidoreductase (FOR), has now been characterized. FOR is a homotetramer with a mass of 280 kDa and contains approximately 1 W atom, 4 Fe atoms, and 1 Ca atom per subunit, together with a pterin cofactor. The low recovery of FOR activity during purification was attributed to loss of sulfide, since the purified enzyme was activated up to fivefold by treatment with sulfide (HS-) under reducing conditions. FOR uses P. furiosus ferredoxin as an electron acceptor (Km = 100 microM) and oxidizes a range of aldehydes. Formaldehyde (Km = 15 mM for the sulfide-activated enzyme) was used in routine assays, but the physiological substrate is thought to be an aliphatic C5 semi- or dialdehyde, e.g., glutaric dialdehyde (Km = 1 mM). Based on its amino-terminal sequence, the gene encoding FOR (for) was identified in the genomic database, together with those encoding AOR and GAPOR. The amino acid sequence of FOR corresponded to a mass of 68.7 kDa and is highly similar to those of the subunits of AOR (61% similarity and 40% identity) and GAPOR (50% similarity and 23% identity). The three genes are not linked on the P. furiosus chromosome. Two additional (and nonlinked) genes (termed wor4 and wor5) that encode putative tungstoenzymes with 57% (WOR4) and 56% (WOR5) sequence similarity to FOR were also identified. Based on sequence motif similarities with FOR, both WOR4 and WOR5 are also proposed to contain a tungstobispterin site and one [4Fe-4S] cluster per subunit.
Compressed Sensing Performance Bounds Under Poisson Noise

This paper describes performance bounds for compressed sensing (CS) where the underlying sparse or compressible (sparsely approximable) signal is a vector of nonnegative intensities whose measurements are corrupted by Poisson noise. In this setting, standard CS techniques cannot be applied directly for several reasons. First, the usual signal-independent and/or bounded noise models do not apply to Poisson noise, which is nonadditive and signal-dependent. Second, the CS matrices typically considered are not feasible in real optical systems because they do not adhere to important constraints, such as nonnegativity and photon flux preservation. Third, the typical l2 - l1 minimization leads to overfitting in the high-intensity regions and oversmoothing in the low-intensity areas. In this paper, we describe how a feasible positivity- and flux-preserving sensing matrix can be constructed, and then analyze the performance of a CS reconstruction approach for Poisson data that minimizes an objective function consisting of a negative Poisson log likelihood term and a penalty term which measures signal sparsity. We show that, as the overall intensity of the underlying signal increases, an upper bound on the reconstruction error decays at an appropriate rate (depending on the compressibility of the signal), but that for a fixed signal intensity, the error bound actually grows with the number of measurements or sensors. This surprising fact is both proved theoretically and justified based on physical intuition.
The role of serum phosphate level and acute ischemic bowel disease

The objectives of this study were to determine whether an elevated serum phosphate level is predictive of acute ischemic bowel disease and whether it serves as a prognostic indicator in patients with intestinal ischemia. A retrospective chart review was performed at an urban teaching hospital emergency department. Twenty-three patients with documented acute ischemic bowel disease from 1990 through 1994 were compared with 27 patients with acute abdominal disease entities unrelated to intestinal ischemia. The sensitivity, specificity, and positive and negative predictive values of serum phosphate were 26%, 85%, 60%, and 58% respectively. Levels of phosphate in patients with intestinal ischemia versus controls were 4.20 versus 3.41 mg/dL (P = .1338). The length of bowel necrosis in the experimental group with elevated phosphate versus normal phosphate level was 57.53 cm versus 99.00 cm (P = .4132). Although not statistically significant, linear regression revealed slightly positive correlations in those with elevated phosphate versus normal phosphate level (in the experimental group) with the length of bowel necrosis and duration of hospital stay as r= .155 (P = .4813) and r= .134 (P= .5418), respectively. Serum phosphate level independently has no diagnostic or prognostic value in acute ischemic bowel disease.