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Although academic research has yielded mixed results, candidates and consultants are rational people whose experience persuades them that 'going negative' can be an effective campaign strategy under the right circumstances. And they are almost certainly right, even if their evidence is more anecdotal than systematic. This article considers whether the impact of negative ads is moderated by perceptions of issue ownership, a factor that is known to affect the candidate preferences of some voters. Focusing on the attitudes of those who identify with the party of the targeted candidate, we examine the changes in support and favorability induced by four policy-based attacks against a hypothetical congressional incumbent seeking reelection. Results from an Internet survey experiment suggest that attacks are somewhat more effective among target co-partisans who do not believe that their party is more competent to handle the issue in question, especially when that issue is salient to the individual. Keywords: Political Communications, Negative Campaigning, Issue Ownership, Media and Politics, Election Campaigns, Candidate Preferences, Voting Behavior, Political Ads, Candidate Competence, Partisan Voting, Party Politics, The United States. A pesar de que la investigacion academica haya dado resultados mixtos, los candidatos y los consultores son personas racionales cuya experiencia los convence que la 'publicidad negativa' puede ser una estrategia de campana efectiva bajo las circunstancias adecuadas. Y en general tienen mucha razon, inclusive si su evidencia es mas anecdotica que sistematica. Este articulo considera si el impacto de la publicidad negativa es moderado por percepciones de atribucion de los temas, un factor que tiene la reputacion de afectar las preferencias de candidato de algunos electores. Enfocandose en las actitudes de los que se identifican con el partido del candidato al que se dirige la publicidad, examinamos los cambios en apoyo y favorabilidad que inducen cuatro ataques basados en la politica contra un candidato titular hipotetico que busca la reeleccion. Los resultados de una encuesta experimental por internet sugieren que los ataques son un poco mas efectivos en las personas del mismo partido que no piensan que su partido es mas competente para resolver el problema en cuestion, especialmente cuando ese problema es importante para el individuo. Palabras clave: Comunicaciones politicas, campanas negativas, atribucion de los temas, medios y politica, campanas electorales, preferencias de candidato, comportamiento electoral, publicidad politica, competencia de los candidatos, titulares en el congreso, Estados Unidos. [Please note: Some non-Latin characters were omitted from this article] [Please note: Some non-Latin characters were omitted from this article], Most Americans of a certain age will recall the infamous 1988 campaign video of Michael Dukakis, Democratic presidential nominee, riding around in a tank and wearing a silly looking helmet [...]

Transition state structures are central to the rates and outcomes of chemical reactions, but their fleeting existence often leaves their properties to be inferred rather than observed. By treating polybutadiene with a difluorocarbene source, we embedded gem-difluorocyclopropanes (gDFCs) along the polymer backbone. We report that mechanochemical activation of the polymer under tension opens the gDFCs and traps a 1,3-diradical that is formally a transition state in their stress-free electrocyclic isomerization. The trapped diradical lives long enough that we can observe its noncanonical participation in bimolecular addition reactions. Furthermore, the application of a transient tensile force induces a net isomerization of the trans-gDFC into its less-stable cis isomer, leading to the counterintuitive result that the gDFC contracts in response to a transient force of extension. 10.1126/science.1193412

The aim of this study was to characterize the 24-h and diurnal variability of urinary protein excretion and identify the prevalence of orthostatic proteinuria (OP) in healthy children. Upright, supine, and 24-h total urinary protein (UrTP) and creatinine clearance (CrCl) were measured in 91 healthy children ages 6-19 years. Urinary protein and creatinine excretions were calculated and examined by gender, age, Tanner stage, and body mass index (BMI). Orthostatic proteinuria (OP) was defined as a 24-h UrTP >100 mg/m2 with a normal supine UrTP (10 years and BMI >85%. In children with OP, a first morning UPcr shows a value in the normal range, whereas a random daytime UPcr is elevated. There exists a diurnal variability in urinary protein excretion that is exaggerated in participants with OP. UPcr reliably estimates 24-h UrTP. Using current pediatric criteria, OP is very common, particularly in boys. A normal first morning UPcr ratio indicates that a child with elevated random urinary protein has OP. Keywords Orthostatic proteinuria * Creatinine clearance * Body mass index * Protein/creatinine ratio, Introduction Whether a urinalysis is performed as part of routine screening or because of suspicion of renal disease, proteinuria is a common finding in children. Although the cost effectiveness of [...]

Summary This article discusses the visual acuity required by drivers in the UK to comply with the law, and sets out how these requirements will change over the next four [...]

Evidence suggests that mistrust of government contributes directly to a lack of support for social welfare programs. An alternative explanation, however, is that many citizens are ambivalent concerning government and [...]

Elections are sometimes seen as legitimizing institutions, promoting system-level support among citizens by allowing them to have input into the political process. However, prior research has found that this is less true among supporters of losing candidates, who often exhibit lower levels of political trust and satisfaction with democracy. We analyze NES survey data from 1964 to 2004, as well as surveys from Florida and the nation following the controversial presidential election of 2000, and find that (1) losers exhibit lower levels of political trust, satisfaction with democracy, confidence that government is responsive to citizens, and in early 2001 were less inclined to extend legitimacy to the newly elected president; (2) losers also are more likely to endorse 'rationalizations' as explanations of the election outcome, to be less satisfied with the choice of candidates offered in the election, and to perceive the electoral process as unfair; and (3) voter interpretations of the election mediate the relationships between winning/losing on the one hand, and trust, responsiveness, and satisfaction with democracy on the other. These findings suggest that the so-called legitimizing function of elections is far from a universal phenomenon.

Dynamic light scattering is used as a sesitive probe of hybridization on DNA-functionalized colloidal gold nanoparticles. The pronounced deviation from Langmuir adsorption behavior is greater for longer duplexes, and it is therefore, consistent with electrostatic repulsion between densely packed oligonucleotides.

Recent research has recognized that many people simultaneously hold positive and negative attitudes about important political issues. In this article, we review the concept of attitudinal ambivalence and propose a survey-based measure of ambivalence adapted from the experimental literature. Extending our earlier work on abortion, analysis of a statewide telephone survey of Florida residents reveals that (1) many people have ambivalent attitudes about issues related to gay and lesbian rights; (2) the amount of ambivalence varies according to the specific rights in question (military service, gay marriage and adoption, membership in youth organizations such as Boy Scouts, and others); (3) ambivalence on gay rights is to some extent a function of conflict among citizens' underlying core values; and (4) under certain circumstances, ambivalence appears to mediate the relationship between a person's issue preferences with regard to gay rights and his or her evaluation of political leaders and institutions.

Autocatalysis and chemical amplification are characteristic properties of living systems, and they give rise to behaviors such as increased sensitivity, responsiveness, and self-replication. Here we report a synthetic system in which a unique form of compartmentalization leads to nonlinear, autocatalytic behavior. The compartment is a reversibly formed capsule in which a reagent is sequestered. Reaction products displace the reagent from the capsule into solution and the reaction rate is accelerated. The resulting self-regulation is sensitive to the highly selective molecular recognition properties of the capsule.

A new study uses fluorescence resonance energy transfer to investigate the thermodynamics and kinetics of multicomponent assembly in organic solution.

Gas phase SN2 was examined for translational energy dependence and potential energy, along with addition-elimination reactions.

Encapsulation complexes are reversibly formed assemblies in which small molecule guests are completely surrounded by large molecule hosts. The assemblies are held together by weak intermolecular forces and are dynamic: they form and dissipate on time scales ranging from milliseconds to days - long enough for many interactions, even reactions, to take place within them. Little information is available on the exchange process, how guests get in and out of these complexes. Here we report that these events can be slow enough for conventional kinetic studies, and reactive intermediates can be detected. Guest exchange has much in common with familiar chemical substitution reactions, but differs in some respects: no covalent bonds are made or broken, the substrate is an assembly rather than a single molecule, and at least four molecules are involved in multiple rate-determining steps.

The acids adsorbed in chromatographic silica gel have enhanced catalytic activity and are substantially used in heterogeneous acid-catalyzed isomerization of allene and dimerization of the corresponding 1,3-diene; Friedel-Crafts cyclodehydration of alcohols; cyclization of (R)-citronellal, the related diester and the 1,5-cyclooctadiene and Rupe rearrangement of alkynol. The treatment of alumina with different types of acids except HCl show no improved acidic character.

60 women and 60 men between the ages of 18 and 45 years (M=30.5, SD = 9.6) were categorized by sex, age, and birth order (only child, firstborn, last-born) to assess the differences among the adult only-child, the youngest child, and the oldest child in autonomous characteristics and cohesiveness in family interaction. Analysis of the responses on a biographical data sheet, the California Psychological Inventory, and the Family Adaptability Cohesion Scales III showed that main effects for birth order and sex are significant in the process of separation-individuation and that the only child is less autonomous than the oldest child.

The application of prepared silica gel and alumina facilitated the rapid hydrohalogenation of different alkenes using acidic chlorine, bromine and iodine. The syn stereoselective surface-mediated addition prevented the occurrence of competing radical addition during hydrobromination. Moreover, the concurrent use of organic and inorganic halides of the form HX allowed the in situ preparation of hydrogen halides.

Political efficacy has been studied extensively since the 1950s, but analysts have never been fully satisfied with its measurement. After considerable testing, four new questions tapping internal political efficacy were added to the 1988 National Election Study. Our investigation shows that inter-item correlations among these questions indicate high internal consistency, that by both exploratory and confirmatory factor analysis the items measure a single concept distinct from external efficacy and political trust, that the measurement model is robust across major subgroups, and that the overall scale is externally valid and provides a good distribution of efficacy scores across the population. Further, the results of an order experiment in the survey suggest that responses are unaffected by mode of presentation. In short, the four new questions constitute the most satisfactory measure of internal political efficacy to date.

Rates of [S.sub.N]2 reactions of chloride ion with methyl- and tert-butyl-substituted chloroacetonitrile were measured by using Fourier transform-ion cyclotron resonance spectrometry to follow the isotopic exchange reaction. Barrier heights for these reactions indicate that steric effects in the gas phase are diminished relative to apparent steric effects in solution. We attribute the increased barrier in solution to a solvation effect. Monte Carlo simulations done using statistical perturbation theory confirm that steric hindrance to solvation contributes to [S.sub.N]2 barriers in solution., In the [S.sub.N]2 nucleophilic displacement reaction, a nucleophile, Z (often negatively charged), reacts with a saturated carbon and displaces a leaving group, Y (Scheme 1). Increasing the size of the [...]

The relative translational energy of one set of reactants in the gas-phase equilibrium between chloride ion and chloroacetonitrile [.sup.35Cl.sup.-] + [.sup.37ClCH.sub.2]CN ?? [.sup.37Cl.sup.-] + [.sup.35ClCH.sub.2]CN is varied without affecting the energy distribution of the other set. The steady-state ratio of ionic isotopes changes so that there is an increase in the concentration of energized reactants. The ratio provides a measure of the translational energy dependence of the rate constant for the bimolecular nucleophilic substitution ([S.sub.N]2) reaction. The observed energy dependence is indistinguishable from that predicted by Rice-Ramsperger-Kassel-Marcus theory, suggesting that the increased translational energy redistributes statistically in the collision complex., We report here two interesting results obtained in a study of the translational energy dependence of the gas-phase, chloride-exchange reaction of chloroacetonitrile [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] where [k.sub.f] [...]

Single-molecule force spectroscopy is used for observing the irreversible extension of a gem-dibromocyclopropane (gDBC)-functionalized polybutadiene under tension, a process similar to polymer necking at a single-molecule level. The rearrangement has represented a new mechanism for localized stress relief in polymers and polymers networks under load, and the quantification of the force dependency has provided a benchmark value for studying mechanically triggered chemistry in bulk polymers.

Several NMR titrations are conducted to determine the bidning affinities of the numerous short and flexible aryl triazole oligomers. The donor ability of the solvent is shown to act as the major determinant of the strength of the binding interaction.

The reactions of chloride ion with a series of alkyl chloronitriles were analyzed to explore the contribution of solvation to the overall steric effects of [S.sub.N]2 reactions observed in solution. The weak size dependence in the system which is in sharp contrast with other ionic system is found to result from the compensation between a direct shielding effect of the substituent and an indirect ionic solvation effect, which arises from the geometric perturbations introduced by the substitution.

Irradiation of dimethylbenzil within a cylindrical capsule has given bright green phosphorescence, while irradiation of benzil and dimethoxybenzil in the same capsule has resulted in high energy blue fluorescence. The difference is because of the geometric restrictions imposed by the capsule's space on its excited guests, forcing a trans-planar conformation in some cases and cis-skewed in others.

The ring opening utrasonification of gem-dichlorocyclopropane (gDCC) copolymers derived from polybutadiene to form 2,3-dichloroalkenes is reported. The ability to specifically and significantly alter the structure of the polymer backbone through a coupled restoring force suggested a new pathway to postsynthetic polymer modification and motivated the design of easily scalable mechanophores for applications in stress-responsive polymers.

The effect of media coverage on psyche of voters was assessed by different study panels. It included the amount of time the campaign advertisements were aired and the number of times the advertisements appeared in the newspapers.

Results from a study based on the data from a three-wave telephone panel survey conducted during the 1998 governor election in Florida, are shown. The results show that a considerable amount of issue-related learning, like candidate's policy stand, group endorsement took place during the course of electoral contest, and learning was especially likely to occur among voters who were more knowledgeable about political affairs and TV news did not make any impact on the issue-based learning among the voters.

Without the constraint of using an enzyme, which is tethered to an Atomic Force Microscope (AFM), a proof-of-principle of an enzyme-catalyzed reaction on an immobilized substrate, a self-assembled monolayer, that present a terminal oligonucleotide, is presented.

Synthetic self-assembled systems combine responsiveness and reversibility with the ability to perform chemical tasks such as molecular recognition and catalysis. An unmet challenge is the construction of polymeric materials that, like nature's tubulin, are simultaneously reversible and capable of useful physical tasks. We report here a class of reversibly formed polymers that show covalent-polymer mechanical integrity in solution and in the solid state. Non-Newtonian, polymeric behavior is observed despite the low molecular weight of the individual subunits and the seemingly weak forces holding the assemblies together. These polymers assemble through self-complementary hydrogen bonding and by physical encapsulation of small molecules; accordingly, the emergent macroscopic structure and function can be controlled by appropriate chemical signals.

Chemists tend to think about the ways in which molecules behave--the shapes they are most likely to adopt, the molecular partners with which they are most likely to bind, or [...]

The application of single-molecule force spectroscopy of bimolecular reactions might reveal the stochastic contributions of individual constituents of a canonical ensemble. The mechanical activation of a leaving group accelerates nucleophilic substitution of dimethyl sulfoxide (DMSO) for substituted pyridines at square-planar pincer Pd(II) metal centers is reported.

Reports state that bridges formed by the self-assembly of multiple molecular components create short-to long-range interactions reminiscent of covalent polymers. The conclusion states that the DNA-based reversible assemblies form bridges between surfaces.

Reports state that bridges formed by the self-assembly of multiple molecular components create short-to long-range interactions reminiscent of covalent polymers. The conclusion states that the DNA-based reversible assemblies form bridges between surfaces.

A study shows that DNA-base reversible assemblies form bridges between surfaces. The forces associated with rupture of these assemblies are independent of polymer bridge length, and they resemble those expected for the isolated associations defining the plover bridges.

Two homologous reversible polymers in which the equilibrium structures are nearly identical but the dissociation dynamics along the main chain differ by ca. 2 orders of magnitude are reported. Steric effect in a ligand exchange process provides a simple but effective mechanism for probing the dynamic properties of reversible polymers and supramolecular systems.

The study states that the dynamic character of noncovalent, reversible molecular assemblies are directly responsible for their unique properties, and the facile exchange of constituents resulted in host structure and guest selectively which were thermodynamically, rather than kinetically, determined. The report revealed a mechanistic continuum for exchange that depends on the structure of the guest(super 10) but does not involve complete dissociation of the capsule or the creation of empty volumes.

Author(s): Jian Chen [1]; Steffi Körner [1]; Stephen L. Craig [2]; Dmitry M. Rudkevich [3]; Julius Rebek, Jr [1] Autocatalysis and chemical amplification are properties of living systems that can [...]

We assessed the relation between conceptual system functioning and expectations about counseling and extend earlier research in 2 ways: (a) Client expectations are linked to a stable personality dimension, and (b) the conceptual system, rather than the conceptual level, model provided the theoretical rationale. Implications of these extensions are discussed. Measures of client conceptual stage and their expectations were taken immediately prior to initial meetings with counselors. Multivariate analysis of variance and discriminant analysis of data from 60 clients revealed theoretically consistent separation between the 4 stages of conceptual functioning on 2 dimensions of expectations about counselor characteristics, attitudes and behaviors. The need to consider the influence of conceptual functioning in counseling process research is supported.

The deposition of large amounts of vibrational energy in the gas-phase SN2 reaction is shown to result in a nonstatistical rise in observed efficiency. An intermediate A was generated from the carbonyl displacement reaction of CH(sub3)O- + CF(sub3)COC1. The nonstatistical behaviour is thought to be due to the fast SN2 reaction relative to the rate of energy redistribution. Studies of reactive intermediates with subnanosecond lifetimes will continue to provide insights into the dynamics of SN2.

Stephen C. Craig, University of Florida Following the Republican sweep in the 1994 midterm, as Bill Clinton was awkwardly proclaiming his continued 'relevance' to the process of national policymaking, few [...]

Distant substituents on an alkyl chain are shown capable of stabilizing the transition state of SN2 reactions. The rate constant for gamma-substitution is very close to that for alpha-substitution despite limited contributions via induction. Previous theoretical findings have argued that resonance is not a contributing factor in accelerating the chlorine exchange reaction of chloroacetonitrile. Findings confirm that a cyano substituent can provide the degree of transition-state stabilization without a significant contribution from resonance.

A study on microsolvated reactions was conducted to extend previous research on certain intramolecularly solvated reactions, where all of the substrates used feature the structure X(CH2)nCl (n being the number of methylene groups separating the chloride leaving group from the solvating substituent X). reactivity strongly correlates with the dipole moment of the solvating group and it is concluded that ion-solvent interactions are secondary in determining reactivity though they are important in determining the stability of the intermediate complex.