Entropy, Dynamics and Instantaneous Normal Modes in a Random Energy Model

It is shown that the fraction f of imaginary frequency instantaneous normal modes (INM) may be defined and calculated in a random energy model(REM) of liquids. The configurational entropy S and the averaged hopping rate among the states R are also obtained and related to f, with the results R~f and S=a+b*ln(f). The proportionality between R and f is the basis of existing INM theories of diffusion, so the REM further confirms their validity. A link to S opens new avenues for introducing INM into dynamical theories. Liquid 'states' are usually defined by assigning a configuration to the minimum to which it will drain, but the REM naturally treats saddle-barriers on the same footing as minima, which may be a better mapping of the continuum of configurations to discrete states. Requirements of a detailed REM description of liquids are discussed

Phenotypic and molecular assessment of seven patients with 6p25 deletion syndrome: Relevance to ocular dysgenesis and hearing impairment

BACKGROUND: Thirty-nine patients have been described with deletions involving chromosome 6p25. However, relatively few of these deletions have had molecular characterization. Common phenotypes of 6p25 deletion syndrome patients include hydrocephalus, hearing loss, and ocular, craniofacial, skeletal, cardiac, and renal malformations. Molecular characterization of deletions can identify genes that are responsible for these phenotypes. METHODS: We report the clinical phenotype of seven patients with terminal deletions of chromosome 6p25 and compare them to previously reported patients. Molecular characterization of the deletions was performed using polymorphic marker analysis to determine the extents of the deletions in these seven 6p25 deletion syndrome patients. RESULTS: Our results, and previous data, show that ocular dysgenesis and hearing impairment are the two most highly penetrant phenotypes of the 6p25 deletion syndrome. While deletion of the forkhead box C1 gene (FOXC1) probably underlies the ocular dysgenesis, no gene in this region is known to be involved in hearing impairment. CONCLUSIONS: Ocular dysgenesis and hearing impairment are the two most common phenotypes of 6p25 deletion syndrome. We conclude that a locus for dominant hearing loss is present at 6p25 and that this locus is restricted to a region distal to D6S1617. Molecular characterization of more 6p25 deletion patients will aid in refinement of this locus and the identification of a gene involved in dominant hearing loss

Assessing Coral Reef Fish Population and Community Changes in Response to Marine Reserves in the Dry Tortugas, Florida, USA

The efficacy of no-take marine reserves (NTMRs) to enhance and sustain regional coral reef fisheries was assessed in Dry Tortugas, Florida, through 9 annual fishery-independent research surveys spanning 2 years before and 10 years after NTMR implementation. A probabilistic sampling design produced precise estimates of population metrics of more than 250 exploited and non-target reef fishes. During the survey period more than 8100 research dives utilizing SCUBA Nitrox were optimally allocated using stratified random sampling. The survey domain covered 326 km2, comprised of eight reef habitats in four management areas that offered different levels of resource protection: the Tortugas North Ecological Reserve (a NTMR), Dry Tortugas National Park (recreational angling only), Dry Tortugas National Park Research Natural Area (a NTMR), and southern Tortugas Bank (open to all types of fishing). Surveys detected significant changes in population occupancy, density, and abundance within management zones for a suite of exploited and non-target species. Increases in size, adult abundance, and occupancy rates were detected for many principal exploited species in protected areas, which harbored a disproportionately greater number of adult spawning fishes. In contrast, density and occupancy rates for aquaria and non-target reef fishes fluctuated above and below baseline levels in each management zone. Observed decreases in density of exploited species below baseline levels only occurred at the Tortugas Bank area open to all fishing. Our findings indicate that these NTMRs, in conjunction with traditional fishery management control strategies, are helping to build sustainable fisheries while protecting the fundamental ecological dynamics of the Florida Keys coral-reef ecosystem

Mean-atom-trajectory model for the velocity autocorrelation function of monatomic liquids

We present a model for the motion of an average atom in a liquid or supercooled liquid state and apply it to calculations of the velocity autocorrelation function $Z(t)$ and diffusion coefficient $D$. The model trajectory consists of oscillations at a distribution of frequencies characteristic of the normal modes of a single potential valley, interspersed with position- and velocity-conserving transits to similar adjacent valleys. The resulting predictions for $Z(t)$ and $D$ agree remarkably well with MD simulations of Na at up to almost three times its melting temperature. Two independent processes in the model relax velocity autocorrelations: (a) dephasing due to the presence of many frequency components, which operates at all temperatures but which produces no diffusion, and (b) the transit process, which increases with increasing temperature and which produces diffusion. Because the model provides a single-atom trajectory in real space and time, including transits, it may be used to calculate all single-atom correlation functions.Comment: LaTeX, 8 figs. This is an updated version of cond-mat/0002057 and cond-mat/0002058 combined Minor changes made to coincide with published versio

Quantum transport using the Ford-Kac-Mazur formalism

The Ford-Kac-Mazur formalism is used to study quantum transport in (1) electronic and (2) harmonic oscillator systems connected to general reservoirs. It is shown that for non-interacting systems the method is easy to implement and is used to obtain many exact results on electrical and thermal transport in one-dimensional disordered wires. Some of these have earlier been obtained using nonequilibrium Green function methods. We examine the role that reservoirs and contacts can have on determining the transport properties of a wire and find several interesting effects.Comment: 10 pages, 4 figure

Fragmented in space: the oral history narrative of an Arab Christian from Antioch, Turkey

This study uses the case of Can Kılçıksız, an Arab Christian refugee youth from Antioch, Turkey, to argue that globalization may result in fragmented families and subjectivities and can also accelerate processes initiated by modernity and the construction of national identities. Can Kılçıksız and his siblings now live in Turkey, Germany, France and Finland. His life story suggests that males of Arab Christian origin from Antioch who had access to schooling are more likely to be involved in politics whereas females tend to be drawn to evangelical Christian organizations. The case also suggests that sibling ties might prove more durable in the course of transnational migration than conjugal ties. The case of Can Kılçıksız shows that the time/space linked to childhood through memory can play an important role in identity construction of subjects circulating in transnational space

Multiple Dimensions of the Moral Majority Platform: Shifting Interest Group Coalitions

The issues raised by the New Political Right and the Moral Majority have overlapped in recent political history. Researchers have assumed that a single additive scale across conservative issues can identify the base of support for the Moral Majority as an organization. We examine general support for the Moral Majority separately from support for six specific issues: teaching creationism, voluntary public school prayer, military defense spending, gun control, pornography and abortion. Data are from a 1982 random sample of adult respondents from Nebraska (N = 1907). Overall, support for the Moral Majority organization is low. Discriminant analysis identifies fundamentalist and evangelical religious affiliation and Biblical literalism as independent predictors of support for the Moral Majority per se. Education increases knowledge of the organization, but does not influence support for it. Respondents with high income levels are more likely to support the Moral Majority organization. These findings contradict theories of both status politics and cultural fundamentalism. Support for the six specific platform items also varies considerably and is affected by religious conservatism and, independently, by other attitudinal and demographic indicators including age, sex, income, rural residence, education and perception of declining economic conditions. These patterns do not entirely fit the predictions of status politics or cultural fundamentalism theories. Rather, they provide evidence that distinct coalitions form on specific issues. Our conclusion is that a simple additive index of support for the Moral Majority masks these differences and oversimplifies complex patterns of coalitions in the religio-political arena

Mutational Analyses of the Influenza A Virus Polymerase Subunit PA Reveal Distinct Functions Related and Unrelated to RNA Polymerase Activity

Influenza A viral polymerase is a heterotrimeric complex that consists of PA, PB1, and PB2 subunits. We previously reported that a di-codon substitution mutation (G507A-R508A), denoted J10, in the C-terminal half of PA had no apparent effect on viral RNA synthesis but prevented infectious virus production, indicating that PA may have a novel role independent of its polymerase activity. To further examine the roles of PA in the viral life cycle, we have now generated and characterized additional mutations in regions flanking the J10 site from residues 497 to 518. All tested di-codon mutations completely abolished or significantly reduced viral infectivity, but they did so through disparate mechanisms. Several showed effects resembling those of J10, in that the mutant polymerase supported normal levels of viral RNA synthesis but nonetheless failed to generate infectious viral particles. Others eliminated polymerase activity, in most cases by perturbing the normal nuclear localization of PA protein in cells. We also engineered single-codon mutations that were predicted to pack near the J10 site in the crystal structure of PA, and found that altering residues K378 or D478 each produced a J10-like phenotype. In further studies of J10 itself, we found that this mutation does not affect the formation and release of virion-like particles per se, but instead impairs the ability of those particles to incorporate each of the eight essential RNA segments (vRNAs) that make up the viral genome. Taken together, our analysis identifies mutations in the C-terminal region of PA that differentially affect at least three distinct activities: protein nuclear localization, viral RNA synthesis, and a trans-acting function that is required for efficient packaging of all eight vRNAs

Assessing road effects on bats: the role of landscape, road features, and bat activity on road-kills

Recent studies suggest that roads can significantly impact bat populations. Though bats are one of the most threatened groups of European vertebrates, studies aiming to quantify bat mortality and determine the main factors driving it remain scarce. Between March 16 and October 31 of 2009, we surveyed road-killed bats daily along a 51-km-long transect that incorporates different types of roads in southern Portugal. We found 154 road-killed bats of 11 species. The two most common species in the study area, Pipistrellus kuhlii and P. pygmaeus, were also the most commonly identified road-kill, representing 72 % of the total specimens collected. About two-thirds of the total mortality occurred between mid July and late September, peaking in the second half of August. We also recorded casualties of threatened and rare species, including Miniopterus schreibersii, Rhinolophus ferrumequinum, R. hipposideros, Barbastella barbastellus, and Nyctalus leisleri. These species were found mostly in early autumn, corresponding to the mating and swarming periods. Landscape features were the most important variable subset for explaining bat casualties. Road stretches crossing or in the vicinity of high-quality habitats for bats—including dense Mediterranean woodland (‘‘montado’’) areas, water courses with riparian gallery, and water reservoirs—yielded a significantly higher number of casualties. Additionally, more roadkilled bats were recorded on high-traffic road stretches with viaducts, in areas of higher bat activity and near known roosts

Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?

Major roads can reduce bat abundance and diversity over considerable distances. To mitigate against these effects and comply with environmental law, many European countries install bridges, gantries or underpasses to make roads permeable and safer to cross. However, through lack of appropriate monitoring, there is little evidence to support their effectiveness. Three underpasses and four bat gantries were investigated in northern England. Echolocation call recordings and observations were used to determine the number of bats using underpasses in preference to crossing the road above, and the height at which bats crossed. At gantries, proximity to the gantry and height of crossing bats were measured. Data were compared to those from adjacent, severed commuting routes that had no crossing structure. At one underpass 96% of bats flew through it in preference to crossing the road. This underpass was located on a pre-construction commuting route that allowed bats to pass without changing flight height or direction. At two underpasses attempts to divert bats from their original commuting routes were unsuccessful and bats crossed the road at the height of passing vehicles. Underpasses have the potential to allow bats to cross roads safely if built on pre-construction commuting routes. Bat gantries were ineffective and used by a very small proportion of bats, even up to nine years after construction. Most bats near gantries crossed roads along severed, pre-construction commuting routes at heights that put them in the path of vehicles. Crossing height was strongly correlated with verge height, suggesting that elevated verges may have some value in mitigation, but increased flight height may be at the cost of reduced permeability. Green bridges should be explored as an alternative form of mitigation. Robust monitoring is essential to assess objectively the case for mitigation and to ensure effective mitigation