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Dimeric indole alkaloids are structurally diverse natural products that have attracted significant attention from the synthetic and biosynthetic communities. Here we describe the characterization of a P450 monooxygenase CnsC from Penicillium that catalyzes the heterodimeric coupling between two different indole moieties, tryptamine and aurantioclavine, to construct vicinal quaternary stereocenters and yield the heptacyclic communesin scaffold. We show, using biochemical characterization, substrate analogs, and computational methods, that CnsC not only catalyzes the C3-C3 carbon-carbon bond formation, but also controls the regioselectivities of the pair of subsequent aminal bond formations to yield the communesin core. The use of ω-N-methyltryptamine and tryptophol in place to tryptamine led to the enzymatic synthesis of isocommunesin compounds, which have not been isolated to date.

We introduce the notion of a strong L-space, a closed, oriented rational homology 3-sphere whose Heegaard Floer homology can be determined at the chain level. We prove that the fundamental group of a strong L-space is not left-orderable. Examples of strong L-spaces include the double branched covers of alternating links in S^3.

The transition states of aldol reactions catalyzed by vicinal diamines are characterized with density functional calculations. It was found that a cyclic transition state involving a nine-membered hydrogen-bonded ring is preferred. The crown (chair–chair) conformations of the transition state account for the observed stereoselectivity of these reactions.

A well-known conjecture states that for any $l$-component link $L$ in $S^3$, the rank of the knot Floer homology of $L$ (over any field) is less than or equal to $2^{l-1}$ times the rank of the reduced Khovanov homology of $L$. In this paper, we describe a framework that might be used to prove this conjecture. We construct a modified version of Khovanov homology for links with multiple basepoints and show that it mimics the behavior of knot Floer homology. We also introduce a new spectral sequence converging to knot Floer homology whose $E_1$ page is conjecturally isomorphic to our new version of Khovanov homology; this would prove that the conjecture stated above holds over the field $\mathbb{Z}_2$., Published version. 46 pages, 5 figures

We investigate constraints on embeddings of a non-orientable surface in a $4$-manifold with the homology of $M \times I$, where $M$ is a rational homology $3$-sphere. The constraints take the form of inequalities involving the genus and normal Euler class of the surface, and either the Ozsv\'ath--Sazb\'o $d$-invariants or Atiyah--Singer $\rho$-invariants of $M$. One consequence is that the minimal genus of a smoothly embedded surface in $L(2p,q) \times I$ is the same as the minimal genus of a surface in $L(2p,q)$. We also consider embeddings of non-orientable surfaces in closed $4$-manifolds., Comment: Primary article by Adam Levine, Daniel Ruberman and Saso Strle, with an appendix by Ira Gessel. 54 pages, 6 figures

The present study examined possible parallels between the structure of human visuospatial abilities and the organization of the neural systems. Forty-eight participants were tested on seven speeded visuospatial tasks. Three of these tasks were constructed so as to rely primarily on known ventral stream functions and four were constructed so as to rely primarily on known dorsal stream functions. Both sets of tasks spanned approximately the same range of difficulty as indexed by both the speed and accuracy of decision making. Factor analysis of response times on the seven tasks revealed only two significant factors. The putative ventral stream tasks all loaded heavily on one factor (mean loading=0.843) but only weakly on the other factor (mean loading=0.222); the putative dorsal stream tasks showed the opposite pattern in that they all loaded heavily on the second factor (mean loading=0.828) but only weakly on the first factor (mean loading=0.229). These findings are consistent with the hypothesis that human visuospatial abilities can be classified using categories based on the specializations of underlying neural structures and systems.

Crime is central to the public debate about the state of American society. Citizens consistently express great concern about the issue and are increasingly calling for punitive policies, such as “three strikes” and the death penalty. In response, politicians and policymakers have allocated larger and larger shares of their budgets to crime control. This is ironic given that the population-adjusted crime rate has declined in recent years. This article addresses the paradox by focusing on the role of television news. A content analysis of local television news in a major media market demonstrates that coverage of crime features two important cues: Crime is violent, and criminals are nonwhite. We translate these media biases into an experimental design that manipulates the level of violence and the race of the perpetrator to test the relevance of these cues to public thinking about crime. The results indicate that race works independently and in conjunction with racial stereotypes to influence people's concern about crime and their willingness to attribute criminal behavior to breakdowns in the African-American community. We conclude by discussing the implications of our findings for race relations, the practice of journalism, and public policy.

can do quite well in seeking policy benefits. In the case of the Contract With America, conservative business interests joined forces with Republican legislators and communications consultants to promote a legislative program with clear beneficiaries. Those who are organized and have big financial interests can gain disproportionate government benefits. All of this suggests that Schattschneider's (1960) fears about the interest group chorus singing with an upper-class bias are coming true.

We show that the integer homology sphere obtained by splicing two nontrivial knot complements in integer homology sphere L-spaces has Heegaard Floer homology rank strictly greater than one. In particular, splicing the complements of nontrivial knots in the 3-sphere never produces an L-space. The proof uses bordered Floer homology., 25 pages. Revised version, to appear in Crelle's Journal. Errors from the original version have been corrected

J/47Te address the effects of negative campaign advertising on turnout. Using a unique jfjJ \ experimental design in which advertising tone is manipulated within the identical X V t audiovisual context, we find that exposure to negative advertisements dropped intentions to vote by 5%. We then replicate this result through an aggregate-level analysis of turnout and campaign tone in the 1992 Senate elections. Finally, we show that the demobilizing effects of negative campaigns are accompanied by a weakened sense of political efficacy. Voters who watch negative advertisements become more cynical about the responsiveness of public officials and the electoral process. It is generally taken for granted that political campaigns boost citizens' involvement-their interest in the election, awareness of and information about current issues, and sense that individual opinions matter. Since Lazarsfeld's pioneering work (Berelson, Lazarsfeld, and McPhee 1954; Lazarsfeld, Berelson, and Gaudet 1948), it has been thought that campaign activity in connection with recurring elections enables parties and candidates to mobilize their likely constituents and "recharge" their partisan sentiments. Voter turnout is thus considered to increase directly with "the level of political stimulation to which the electorate is subjected" (Campbell et al. 1966, 42; Patterson and Caldeira 1983). The argument that campaigns are inherently "stimulating" experiences can be questioned on a variety of grounds. American campaigns have changed dra

We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the field of rational functions over $\mathbb{Z}/2\mathbb{Z}$. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The $(E_2,d_2)$ page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology., 58 pages, 18 figures. Published version, with updated references

This article documents three types of media effects that operated on public opinion during the Persian Gulf crisis and war. First, the level of network news coverage matched the proportion of Gallup poll respondents naming the Gulf crisis as the nation's most important problem (agenda-setting ). Second, use of data from the 1988, 1990, and 1991 National Election Studies (NES) shows that the weight respondents accorded foreign policy performance when evaluating George Bush significantly increased (priming ) in the aftermath of the Gulf crisis. Third, content data (showing that network news coverage was preoccupied with military affairs and highly event oriented) and survey data are coupled to show that respondents reporting higher rates of exposure to television news expressed greater support for a military as opposed to a diplomatic response to the crisis (framing ). In conclusion, it is suggested that these effects, in combination with the nature of the media's information sources, were conducive to legitimizing the administration's perspective on the crisis.

We show that if K is any knot whose Ozsvath-Szabo concordance invariant tau(K) is positive, the all-positive Whitehead double of any iterated Bing double of K is topologically but not smoothly slice. We also show that the all-positive Whitehead double of any iterated Bing double of the Hopf link (e.g., the all-positive Whitehead double of the Borromean rings) is not smoothly slice; it is not known whether these links are topologically slice., 16 pages, 10 figures. v2: This is a substantial revision of v1. We eliminated Section 4 of v1 because it is superceded by arXiv:1008.3349. v3: corrected references

We use the Heegaard Floer obstructions defined by Grigsby, Ruberman, and Strle to show that forty-six of the sixty-seven knots through eleven crossings whose concordance orders were previously unknown have infinite concordance order., 5 pages, 3 tables

We review recent empirical evidence that shows political campaigns are more potent than widely believed, focusing on the conceptual and methodological advances that have produced these findings. Conceptually, a broader definition of effects—that includes learning and agenda-control, as well as vote choice—characterizes contemporary research. This research also features two kinds of interactive models that are more complex than the traditional hypodermic (message-based) approach. The resonance model considers the relationship between message content and receivers’ predispositions, while the strategic model highlights the interactions between competing messages. Finally, we attribute the emergence of stronger evidence in favor of campaign effects to the use of new methodologies including experimentation and content analysis, as well as the more sophisticated use of sample surveys.

Seitdem im Jahre 1947 die ersten Qumrânschriften aufgefunden wurden und nacher Beduinen und wissenschaftliche Forscher weitere wichtige Dokumente entdeckten, hat sich die Literatur zu den Handschriften von Qumrân bis zu einem 'mer a boire' angehauft. Vor allem uber die Funde, den Inhalt der einzelnen Schriften und deren chronologische Ansetzung ist in den verschiedensten Zeitschriften soviel geschrieben, dass es nicht der Muhe lohnen wurde, an dieser Stelle die Fundgeschichte aufs neue zu erzahlen oder auch die bis jetzt veroffentlichten Manuskripte nochmals ihrem Inhalt nach zu beschreiben. ... Zie: Einleitung.

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