246 research outputs found

    A Contribution to the Dissociation and Association of Salicylic Acid

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    The dissociation and the possible association of saolicylic acid was investigated by spectrophotometric measurements and potentiometric titrations of the 2.26 X 10-4 M and 4 X 10-3 M acid. A discrepancy between the experimental colorimetric titration curve and the calculated one between pH 3 and pH 4 was stated. This phenomenon is explained by the assumption that some association reactions might occur. The calculation of the association constants was attempted by means of the least squares method using the titration data obtained

    Metodologia para a avaliação da vulnerabilidade sísmica do património religioso: caso de estudo - Faial e Pico, Açores

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    Os sismos representam uma das grandes causas de danos graves e perda do património histórico e arquitectónico. Qualquer intervenção de reabilitação destes edifícios deve partir de uma cuidada avaliação e análise da sua vulnerabilidade sísmica, de modo a desenvolver, se necessário, estratégias de reforço sísmico adequadas. O principal objectivo do presente artigo é estudar a vulnerabilidade sísmica do património religioso das ilhas do Faial e do Pico, nos Açores. Para tal, numa primeira parte deste trabalho, é proposta uma metodologia para o diagnóstico e registo do grau de dano em igrejas após a ocorrência de um sismo, assim como para a avaliação da vulnerabilidade associada a estas. A partir da análise dos danos observados em dezasseis igrejas afectadas pelo sismo de 9 de Julho de 1998 nos Açores, é elaborada uma base de dados que, para além de reunir as características de cada igreja estudada, apoia o cálculo simplificado do índice de dano, vulnerabilidade e coeficiente de segurança global. O campanário das torres sineiras é um elemento particularmente vulnerável aos sismos, devido à sua geometria típica. Por um lado, a existência de grandes aberturas a certos níveis produz tipicamente elementos verticais muito esbeltos. Por outro lado, a elevada concentração de massa no topo das torres também contribui para esta vulnerabilidade. Assim, na segunda parte deste trabalho, é aplicada a metodologia italiana, proposta na Linee Guida per la Valutazione e Reduzione del Rischio Sísmico del Patrimônio Culturale, aos campanários de duas igrejas localizadas na ilha do Pico, com base num modelo mecânico simplificado para a avaliação da vulnerabilidade deste tipo de estruturas. Com o trabalho desenvolvido, pretende-se contribuir para uma sistematização de processos de inspecção e registo de informação relativa a igrejas, com vista a apoiar estratégias de intervenção quer em situações de pós-sismo, quer na mitigação do risco sísmico destas estruturas

    Report on the Organizational Climates of Congress

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    The aim of this study is to gain a better understanding of Congress by attending to how the people who serve in the institution perceive Congress’ procedures, norms and expectations for their behavior. What are the “unwritten rules” that members and staff come to understand as they experience the institution? What types of behaviors are rewarded and encouraged inside Congress? How do these shared organizational perceptions and practices, in turn, shape how members of Congress work with other members, both within and between the two major parties? We took an interdisciplinary approach to understanding the climate and culture of Congress. We conducted 60 interviews with either former Members of Congress or House staff members. We found that the reward structure inside congressional parties is oriented around relationships. Results: The Structure of Intraparty Rewards Members advance in influence via their success in cultivating the esteem of their colleagues. This entails developing a reputation for expertise and integrity. But it also means building a social network by doing favors for others, especially fundraising. Members are seen as not considerate of others or unwilling to be “team players” have difficulty rising in influence. Individual members generally advance their standing in the party by building consensus rather than winning conflicts. But coalitions of members can gain greater weight within their party by being seen as winning conflicts. The central importance of relationships in Congress is consistent with patterns prevailing in fluid organizations more generally. The Climate of Intraparty Conflict and Cooperation Nearly all respondents described themselves as feeling free to speak up when they disagreed with their party leaders, though certain norms govern and restrain such behavior. In particular, disagreements with leaders should be raised in private or in party caucus but not in public or the press, though there was also recognition that not all members adhered to this norm. Similarly, verbal disagreement with party leaders is accepted, but active resistance of the party is frowned upon and subject to sanction. Tolerance of intraparty dissent is reasonably high, but members do at times experience pressure to go along with leaders, particularly on highly salient issues central to the party’s program. The Climate of Interparty Conflict and Cooperation Our findings paint a somewhat mixed picture of the state of cooperation across the aisle in Congress, where elements of collaborative and dominating culture are evident. Our interviews also reveal that on issues that are less visible and less important to the parties, working across the aisle to achieve “win-win” outcomes is considered possible and common even in today’s Congress. Many legislators and staff members are interested in working with colleagues across the aisle and have experience doing so. Moreover, clear paths lead to interpersonal cooperation, namely serving together on a committee, personal friendships, and common district interests.1. William and Flora Hewlett Foundation 2. The Democracy Fun

    Cytoplasmic Intron Sequence-Retaining Transcripts Can Be Dendritically Targeted via ID Element Retrotransposons

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    SummaryRNA precursors give rise to mRNA after splicing of intronic sequences traditionally thought to occur in the nucleus. Here, we show that intron sequences are retained in a number of dendritically-targeted mRNAs, by using microarray and Illumina sequencing of isolated dendritic mRNA as well as in situ hybridization. Many of the retained introns contain ID elements, a class of SINE retrotransposon. A portion of these SINEs confers dendritic targeting to exogenous and endogenous transcripts showing the necessity of ID-mediated mechanisms for the targeting of different transcripts to dendrites. ID elements are capable of selectively altering the distribution of endogenous proteins, providing a link between intronic SINEs and protein function. As such, the ID element represents a common dendritic targeting element found across multiple RNAs. Retention of intronic sequence is a more general phenomenon than previously thought and plays a functional role in the biology of the neuron, partly mediated by co-opted repetitive sequences

    Evidence of acaricide resistance in different life stages of Amblyomma mixtum and Rhipicephalus microplus (Acari: Ixodidae) collected from the same farm in the state of Veracruz, Mexico.

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    The objectives of this study were to evaluate the resistance of Amblyomma mixtum and Rhipicephalus microplus ticks from co-infested bovines from the Veracruz region in Mexico to different acaricide families and to demonstrate the viability of the packet test on different A. mixtum instars. The following acaricide families were used: a combination (cypermethrin 15 g+chlorpyrifos 25 g+citronella 1 g+butoxide piperonyl 15 g), amidine (formamidine 12.5 g), pyrethroid (cypermethrin 15 g), and organophosphate (dichlorvos 60 g+chlorpyrifos 20 g). Regarding the packet test in both species, resistance was found for the pyrethroid and amidine families in A. mixtum and R. microplus, as efficacy did not surpass 40 %, including in immature instars; regarding the adult immersion test in R. microplus, the efficacy was 93.3 % for the amidine family and 26.2 % for the pyrethroid family. The proposed methodology is an alternative technique to optimize resistance detection in immature ticks with a heteroxenous life cycle

    Bond-disordered Anderson model on a two dimensional square lattice - chiral symmetry and restoration of one-parameter scaling

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    Bond-disordered Anderson model in two dimensions on a square lattice is studied numerically near the band center by calculating density of states (DoS), multifractal properties of eigenstates and the localization length. DoS divergence at the band center is studied and compared with Gade's result [Nucl. Phys. B 398, 499 (1993)] and the powerlaw. Although Gade's form describes accurately DoS of finite size systems near the band-center, it fails to describe the calculated part of DoS of the infinite system, and a new expression is proposed. Study of the level spacing distributions reveals that the state closest to the band center and the next one have different level spacing distribution than the pairs of states away from the band center. Multifractal properties of finite systems furthermore show that scaling of eigenstates changes discontinuously near the band center. This unusual behavior suggests the existence of a new divergent length scale, whose existence is explained as the finite size manifestation of the band center critical point of the infinite system, and the critical exponent of the correlation length is calculated by a finite size scaling. Furthermore, study of scaling of Lyapunov exponents of transfer matrices of long stripes indicates that for a long stripe of any width there is an energy region around band center within which the Lyapunov exponents cannot be described by one-parameter scaling. This region, however, vanishes in the limit of the infinite square lattice when one-parameter scaling is restored, and the scaling exponent calculated, in agreement with the result of the finite size scaling analysis.Comment: 23 pages, 11 figures. RevTe

    The level of air pollution in the impact zone of coal-fired power plant (Karaganda City) using the data of geochemical snow survey (Republic of Kazakhstan)

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    Coal-fired power plants emissions impact the air quality and human health. Of great significance is assessment of solid airborne particles emissions from those plants and distance of their transportation. The article presents the results of air pollution assessment in the zone of coal-fired power plant (Karaganda City) using snow survey. Based on the mass of solid airborne particles deposited in snow, time of their deposition on snow at the distance from 0.5 to 4.5 km a value of dust load has been determined. It is stated that very high level of pollution is observed at the distance from 0.5 to 1 km. there is a trend in decrease of dust burden value with the distance from the stacks of coal-fired power plant that may be conditioned by the particle size and washing out smaller ash particles by ice pellets forming at freezing water vapour in stacks of the coal-fired power plant. Study in composition of solid airborne particles deposited in snow has shown that they mainly contain particulates of underburnt coal, Al-Si- rich spheres, Fe-rich spheres, and coal dust. The content of the particles in samples decreases with the distance from the stacks of the coal-fired power plant

    Water velocity limits the temporal extent of herbivore effects on aquatic plants in a lowland river

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    The role of herbivores in regulating aquatic plant dynamics has received growing recognition from researchers and managers. However, the evidence for herbivore impacts on aquatic plants is largely based on short-term exclosure studies conducted within a single plant growing season. Thus, it is unclear how long herbivore impacts on aquatic plant abundance can persist for. We addressed this knowledge gap by testing whether mute swan (Cygnus olor) grazing on lowland river macrophytes could be detected in the following growing season. Furthermore, we investigated the role of seasonal changes in water current speed in limiting the temporal extent of grazing. We found no relationship between swan biomass density in 1 year and aquatic plant cover or biomass in the following spring. No such carry-over effects were detected despite observing high swan biomass densities in the previous year from which we inferred grazing impacts on macrophytes. Seasonal increases in water velocity were associated with reduced grazing pressure as swans abandoned river habitat. Furthermore, our study highlights the role of seasonal changes in water velocity in determining the length of the mute swan grazing season in shallow lowland rivers and thus in limiting the temporal extent of herbivore impacts on aquatic plant abundance
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