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Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical–geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical–geographical conditions and broader institutional networks of power and influence.

Silencing of transcription in Saccharomyces cerevisiae has several links to DNA replication, including a role for the origin recognition complex (ORC), the DNA replication initiator, in both processes. In addition, the establishment of silencing at the HML and HMR loci requires cells to pass through the S phase of the cell cycle. Passage through S phase was required for silencing of HMR even under conditions in which ORC itself was no longer required. The requirement for ORC in silencing of HMR could be bypassed by tethering the Sir1 protein to the HMR-E silencer. However, ORC had a Sir1-independent role in transcriptional silencing at telomeres. Thus, the role of ORC in silencing was separable from its role in initiation, and the role of S phase in silencing was independent of replication initiation at the silencers

The Sir1 protein plays a key role in establishing a silent chromatin structure at the cryptic mating-type loci HMR and HML in Saccharomyces cerevisiae by interacting with the bromo-adjacent homology (BAH) domain of the Orc1p subunit of the origin recognition complex (ORC). Here, we present the high-resolution crystal structures of the ORC interaction region (OIR) of Sir1p and that of the complex formed between the OIR and BAH domains. Amino acids within the OIR previously shown to be required for a Sir1p/ORC interaction are presented on a conserved, convex surface that forms a complementary interface with a concave region of the Orc1 BAH domain that is critical for transcriptional silencing. The OIR/BAH interaction surface comprises a network of hydrophobic and polar/ionic interactions between discrete structural modules in each protein and involves several residues that were not implicated in previous studies. These data provide important structural insights into a protein-protein interaction critical for the formation of a specialized chromatin domain within eukaryotic chromosomes.

Baculovirus-expressed recombinant Sir3p (rSir3p) has been purified to near homogeneity, and its binding to naked DNA, mononucleosomes, and nucleosomal arrays has been characterized in vitro. At stoichiometric levels rSir3p interacts with intact nucleosomal arrays, mononucleosomes, and naked DNA, as evidenced by formation of supershifted species on native agarose gels. Proteolytic removal of the core histone tail domains inhibits but does not completely abolish rSir3p binding to nucleosomal arrays. The linker DNA in the supershifted complexes remains freely accessible to restriction endonuclease digestion, suggesting that both the tail domains and nucleosomal DNA contribute to rSir3p-chromatin interactions. Together these data indicate that rSir3p cross-links individual nucleosomal arrays into supramolecular assemblies whose physical properties transcend those of typical 10-nm and 30-nm fibers. Based on these data we hypothesize that Sir3p functions, at least in part, by mediating reorganization of the canonical chromatin fiber into functionally specialized higher order chromosomal domains.

During the first ten years of a group started in February 1977 by the Avon Probation Service for the treatment of non-violent sex offenders, many of the offenders have shown a high degree of commitment to the group, and attendance levels have run consistently at over 70%. Of 63 men who came to the group during the ten-year study period, 33 completed their stay at the group, 11 left the group prematurely, and 11 never engaged satisfactorily. The remaining eight were still attending the group at the end of the study period. Of the 55 men whose contact with the group had ended, 36 (65%) had not been convicted of further sex offences by the end of the study period.

Partial streamflow diversion due to the siting of hydroelectric generating plants may increase the incidence and degree of water stress in riparian vegetation. This study, conducted on Bishop Creek in the eastern Sierra Nevada (California), compared the water relations of riparian vegetation on paired undiverted (natural flow) and diverted (low flow) reaches. Riparian plants on diverted reaches had reduced stomatal conductance and water potential compared to plants on undiverted reaches in a dry year, but not in a high—runoff year. Juvenile plants on diverted reaches had reduced stomatal conductance and lower midday water potentials relative to surrounding mature trees, a trend that was not observed on undiverted reaches. Predawn water potentials were uniformly high in all species and sites, but low midday water potentials (—1.2 to —1.5 MPa) were observed for most species on diverted reaches. Plants on diverted reaches possessed significantly smaller, thicker leaves and a reduced total leaf area relative to trees on streamside reaches. Reduced community leaf area and effective stomatal control of water loss may allow riparian corridors on diverted reaches to retain their canopies in low—runoff years. However, a long—term consequence of streamflow diversion may be selective mortality of juvenile plants because of the elimination of floods and high flows.

Objectives: To explore family factors that influence sexual behaviors among a group of Black and Hispanic adolescent males. Methods: One hundred seventy-eight subjects were selected from a convenience sample of 431 adolescents who participated in a 1996 Youth Survey conducted in San Bernardino County, California. Results: Having a sibling who was a teen parent was significantly associated with engaging in sexual intercourse among Hispanics. Among Blacks, having a father who was a teen dad was significantly associated with sexual intercourse. Conclusion: Findings showed relationships between family characteristics and sexual attitudes and behaviors among participants.

This paper empirically responds to the critiqued scarcity of studies on the interactional patterns of Anglophone Caribbean families. Using primary cross-sectional data from urban Guyana, a cultural and historic affiliate of the English-speaking Caribbean, the study examines the nature of discipline styles (punitive and non-punitive) and factors that predict their usage. The absence of specific and consistent ethnic and socioeconomic differences in discipline styles found in this study point to a more generalized cultural norm influencing the socialization of children in urban Guyana. The significant gender based discipline patterns observed, support previous arguments relative to the gender segmentation of the Caribbean society. The finding that perception of parental strain is a significant predictor of the variation of discipline styles points to the importance of the personal context of socialization behavior in urban Guyana. Cet article issu de recherches appliquées s'adresse à la critique portant sur le manque d'études des formes d'interaction au sein des familles Anglophone caraibéenes. Utilisant un échantillon pour mieux comprendre les échanges sociaux parmi les citadins de la Guyane; un prototype historique et culturel des Anglophones caraibéens, cette investigation porte sur les différentes formes disciplinaires (avec punition ou non), de même que les facteurs aidant a leur prédictibilité. Vu l'absence d'aucune donnée spécifique et consistente sur les différences ethniques et socio-économiques, on' a pu relever que des normes culturelles générales a influencer la socialisation des jeunes urbain guyanais. La forme de discipline observée est d'influence paternelle. Ceci confirme la vieille croyance suggérant que la société caraibéene est entièrement sous l'empire des hommes. Les résultats révèlent que la perception des soucis parentaux est un indice important touchant à la variété des méthodes disciplinaires, et soulignent la nécessite de placer ces données dans leur contexte pour mieux comprendre le comportement social dans le milieu urbain guyanais. Este ensayo busca compensar, desde una perspectiva empírica, la criticada falta de estudios sobre los modelos de interaccion dentro de las familias anglófonas caribeñas. Tomando como base datos primarios pertenecientes a diferentes sectores de la poblacion de la Guyana urbana—zona cultural e historicamente asociada al Caribe de habla inglesa--en esta investigacion se examinan la naturaleza de los estilos disciplinares y los factores que predicen su uso. La ausencia de diferencias Etnicas y socioeconómicas con carácter específico y consistente en los estilos disciplinares indican la existencia de una norma cultural generalizada como factor de influencia en la socializacion de los niños de la Guyana urbana. Los modelos disciplinares observados, con base en comportamientos de genero, confirman argumentos previos relacionados con la segmentacion por sexos de la sociedad caribeña. El descubrimiento de que la percepción de tensiones familiares actua como un instrumento de predicción significativo en la variación de los estilos disciplinares indica la importancia del contexto personal en el comportamiento de socialización en la Guyana urbana.

Forty patients with inoperable pancreatic cancer were included in a prospective, randomised, controlled trial of multiple chemotherapy. The survival of 19 untreated control patients was compared with that of 21 patients who received an initiation course of intravenous fluorouracil, cyclophosphamide, methotrexate, and vincristine given over five days followed by intravenous fluorouracil and mitomycin given over three or five days at six-week intervals thereafter. Median survival in treated patients was 44 weeks, which was significantly longer than the nine weeks seen in controls. In patients without metastases median survival was 48 weeks in the treated group and 12 weeks in controls. In patients with metastases it was 30 weeks in treated patients and seven weeks in controls. The treatment was well tolerated and seemed to confer a significant prolongation of survival, comparing favourably with previous reports of chemotherapy with or without radiotherapy. If the results are confirmed this regimen may be useful in district general hospital practice.