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Bacterial persistence is a potential cause of antibiotic therapy failure. Antibiotic-tolerant persisters originate from phenotypic differentiation within a susceptible population, occurring with a frequency that can be altered by mutations. Recent studies have proven that persistence is a highly evolvable trait and, consequently, an important evolutionary strategy of bacterial populations to adapt to high-dose antibiotic therapy. Yet, the factors that govern the evolutionary dynamics of persistence are currently poorly understood. Theoretical studies predict far-reaching effects of bottlenecking on the evolutionary adaption of bacterial populations, but these effects have never been investigated in the context of persistence. Bottlenecking events are frequently encountered by infecting pathogens during host-to-host transmission and antibiotic treatment. In this study, we used a combination of experimental evolution and barcoded knockout libraries to examine how population bottlenecking affects the evolutionary dynamics of persistence. In accordance with existing hypotheses, small bottlenecks were found to restrict the adaptive potential of populations and result in more heterogeneous evolutionary outcomes. Evolutionary trajectories followed in small-bottlenecking regimes additionally suggest that the fitness landscape associated with persistence has a rugged topography, with distinct trajectories toward increased persistence that are accessible to evolving populations. Furthermore, sequencing data of evolved populations and knockout libraries after selection reveal various genes that are potentially involved in persistence, including previously known as well as novel targets. Together, our results do not only provide experimental evidence for evolutionary theories, but also contribute to a better understanding of the environmental and genetic factors that guide bacterial adaptation to antibiotic treatment. [ABSTRACT FROM AUTHOR]

A cornerstone of conservation is the designation and management of protected areas ( PAs): locations often under conservation management containing species of conservation concern, where some development and other detrimental influences are prevented or mitigated. However, the value of PAs for conserving biodiversity in the long term has been questioned given that species are changing their distributions in response to climatic change. There is a concern that PAs may become climatically unsuitable for those species that they were designated to protect, and may not be located appropriately to receive newly-colonizing species for which the climate is improving. In the present study, we analyze fine-scale distribution data from detailed resurveys of seven butterfly and 11 bird species in Great Britain aiming to examine any effect of PA designation in preventing extinctions and promoting colonizations. We found a positive effect of PA designation on species' persistence at trailing-edge warm range margins, although with a decreased magnitude at higher latitudes and altitudes. In addition, colonizations by range expanding species were more likely to occur on PAs even after altitude and latitude were taken into account. PAs will therefore remain an important strategy for conservation. The potential for PA management to mitigate the effects of climatic change for retracting species deserves further investigation. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●●, ●●-●●. [ABSTRACT FROM AUTHOR]

Many species are extending their leading-edge (cool) range margins polewards in response to recent climate change. In the present study, we investigated range margin changes at the northern (cool) range margins of 1573 southerly-distributed species from 21 animal groups in Great Britain over the past four decades of climate change, updating previous work. Depending on data availability, range margin changes were examined over two time intervals during the past four decades. For four groups (birds, butterflies, macromoths, and dragonflies and damselflies), there were sufficient data available to examine range margin changes over both time intervals. We found that most taxa shifted their northern range margins polewards and this finding was not greatly influenced by changes in recorder effort. The mean northwards range margin change in the first time interval was 23 km per decade ( N = 13 taxonomic groups) and, in the second interval, was 18 km per decade ( N = 16 taxonomic groups) during periods when the British climate warmed by 0.21 and 0.28 °C per decade, respectively. For the four taxa examined over both intervals, there was evidence for higher rate of range margin change in the more recent time interval in the two Lepidoptera groups. Our analyses confirm a continued range margin shift polewards in a wide range of taxonomic groups. [ABSTRACT FROM AUTHOR]

The publication of the scientific name Monjurosuchus splendens in 1940 documented the first tetrapod fossil of the later world-renowned Jehol Biota. For more than half a century since this discovery, however, Monjurosuchus has remained as a monotypic genus of the family Monjurosuchidae, and the relationships of the family with choristoderes have not been correctly recognized until quite recently. In this paper, a new monjurosuchid is named and described based on a nearly complete skull and postcranial skeleton from the Early Cretaceous Chiufotang Formation exposed near Chaoyang, western Liaoning Province, China. This new material documents the first occurrence of monjurosuchid choristoderes outside the type Lingyuan area, and extends the geological range of the family from the Yixian Formation to the younger Chiufotang Formation. Cladistic analyses were conducted with inclusion of monjurosuchids, and the results support the placement of the family Monjurosuchidae as a primitive clade outside the Neochoristodera. A new classification scheme is proposed for choristoderes on the basis of the recovered phylogenetic framework of the group. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 145, 427–444. [ABSTRACT FROM AUTHOR]

Discusses issues concerning the practice of plagiarism by students. Reasons behind acts of plagiarism by students; Information on the debate over the originality of the book "With Malice Toward None," a biography written by Stephen Oates; Advice on teaching students the proper way of writing research papers.

This article reports the results of a meta-analysis of experimental studies which have examined ten different factors felt to influence response rates to mail surveys. The form of meta-analysis used clearly defines the individual impact of each of the factors examined. Results indicate that prenotification and follow-ups increase the response rate, as does the type of outgoing postage used. Furthermore, studies sponsored by a university receive greater returns. Increases in the size of the monetary incentive used appear to have decreasing marginal gains. Finally, some evidence exists to suggest that the color of the questionnaire influences response rate. [ABSTRACT FROM AUTHOR]

The actin myosin system and the redox state have been implicated in a number of cellular functions and in many pathological conditions. To study the predictions of a new redox theory of actin-myosin interaction we examined the relationship between the redox state and vasoconstriction of rat aorta and dog basilar artery by adrenaline and serotonin. The results show that the contraction induced by these physiological agents can be inhibited and reversed by reducing agents. [ABSTRACT FROM PUBLISHER]

The article focuses on a popular religion in American culture, "speak of the devil." Everyone knows that Christianity has been an elemental force in American culture since the seventeenth century, but many do not know how potent it remains even after almost two centuries of liberalization and modernization. Statistics of the religious beliefs of the people are included and article author views that of course statistics of this sort beg the question whether belief in God or public worship mean the same thing in the late twentieth century that they did in the eighteenth or early nineteenth.

Suggests several improvements regarding issues of public culture and synthesis of the U.S. history in the article "Wholes and Parts: The Need for Synthesis in American History," by Thomas Bender. Definition of public culture; Ways of understanding public culture according to the book "Worlds Apart," by Jean-Christophe Agnew; Significance of the perspective of Agnew to nineteenth- and twentieth-century U.S. history; Obstacles facing historical synthesis.

Introduces a series of essays originally written for the opening night panel of the 1989 Organization of American Historians convention in Saint Louis, Missouri to commemorate the fiftieth anniversary of World War II.

Although exploring the political participation of the poor is of paramount significance in the current social policy and welfare environment, the dearth of quantitative, in-depth analysis speaks to the difficulty of conducting research revolving around the political participation of impoverished citizens. In an attempt to gain a fuller understanding of political participation among the urban poor, we investigated variations in economic hardship, political attitudes, and interactions with government agents of a sample of 462 low-income men and women in one of the poorest congressional districts in the country. By working from a theoretical perspective that allowed us to understand better how urban poverty affects the willingness to participate in the political system, we uncovered important nuances and differences in factors that affected political behavior among citizens living in poverty. Our data revealed two central findings: First, material resources and the demographic attributes usually associated with a propensity to participate politically drove political activism even among urban poor respondents. Second, and more importantly, severe economic hardship, as well as formative contact with government agents whom citizens living in urban poverty routinely face, served as significant experiences that bolstered the willingness to participate in the political system. Ultimately, we conclude that the decision to participate in the political system cannot be divorced from the very specific manner in which citizens encounter government. [ABSTRACT FROM AUTHOR]