Does Micro-CT scanning damage DNA in museum specimens?

X-ray micro-computed tomography and DNA sequencing are useful and increasingly common tools in taxonomy and collections research. Whilst the benefits of each method are continually evaluated and debated individually, how the methods impact each other requires more attention. We compared DNA fragment length and the barcode sequence CO1 in samples throughout a CT-scanning protocol, for a range of X-ray exposures and energies. We found no evidence of DNA damage, but advise caution when using precious or archival material, highlighting the need for further investigations and considering potential areas for research.NatSCA supports open access publication as part of its mission is to promote and support natural science collections. NatSCA uses the Creative Commons Attribution License (CCAL) http://creativecommons.org/licenses/by/2.5/ for all works we publish. Under CCAL authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, and/or copy articles in NatSCA publications, so long as the original authors and source are cited. The attached file is the published version of the article

Kertesz on Fat Graphs?

The identification of phase transition points, beta_c, with the percolation thresholds of suitably defined clusters of spins has proved immensely fruitful in many areas of statistical mechanics. Some time ago Kertesz suggested that such percolation thresholds for models defined in field might also have measurable physical consequences for regions of the phase diagram below beta_c, giving rise to a ``Kertesz line'' running between beta_c and the bond percolation threshold, beta_p, in the M, beta plane. Although no thermodynamic singularities were associated with this line it could still be divined by looking for a change in the behaviour of high-field series for quantities such as the free energy or magnetisation. Adler and Stauffer did precisely this with some pre-existing series for the regular square lattice and simple cubic lattice Ising models and did, indeed, find evidence for such a change in high-field series around beta_p. Since there is a general dearth of high-field series there has been no other work along these lines. In this paper we use the solution of the Ising model in field on planar random graphs by Boulatov and Kazakov to carry out a similar exercise for the Ising model on random graphs (i.e. coupled to 2D quantum gravity). We generate a high-field series for the Ising model on $\Phi^4$ random graphs and examine its behaviour for evidence of a Kertesz line

Studies in the Interaction of Heavy Charged Particles With Matter.

In recent years the technology of thin film preparation and the fabrication of gold surface barrier detectors and their associated electronics have become highly developed. This has enabled improved energy loss measurements to be made more conveniently for a large range of absorbers and charged particles. The basic interaction processes of heavy charged particles with matter have been investigated by analysing the energy spectra of charged particles before and after passing through absorbers. Results concerning the variation in energy loss, stopping power and energy straggling are given for alpha particles and fission fragments in various absorbers. Experimental studies of energy straggling have been carried out for Am-241 alpha particles using surface barrier detectors to observe the energy dispersion following transmission through solid absorbers. Energy straggling of the emitted alpha particles increased with increasing absorber thickness in accordance with theory, until the energy spectra of the helium ions entered the capture and loss region, when the trend is reversed and straggling began to decrease with increasing absorber thickness. An explanation of the phenomenon is given by reference to the stopping power of alpha particles as a function of their energy. Similarly measurements have been made of the energy straggling of Cf-252 fission fragments through air and solid films using a heavy ion surface barrier detector. Analysis of the energy spectra of the heavy and light fragments show a decreasing energy straggling with increasing absorber thickness. Again this and other spectra parameters are explained by reference to stopping power data for fission fragments

Evaluation of the efficacy and safety of high dose short duration enrofloxacin treatment regimen for uncomplicated urinary tract infections in dogs.

BackgroundUncomplicated urinary tract infections (UTI) in dogs usually are treated with antimicrobial drugs for 10-14 days. Shorter duration antimicrobial regimens have been evaluated in human patients.HypothesisA high dose short duration (HDSD) enrofloxacin protocol administered to dogs with uncomplicated UTI will not be inferior to a 14-day treatment regimen with amoxicillin-clavulanic acid.AnimalsClient-owned adult, otherwise healthy dogs with aerobic bacterial urine culture yielding ≥ 10(3) CFU/mL of bacteria after cystocentesis.MethodsProspective, multicenter, controlled, randomized blinded clinical trial. Enrolled dogs were randomized to group 1 (enrofloxacin 18-20 mg/kg PO q24h for 3 days) or group 2 (amoxicillin-clavulanic acid 13.75-25 mg/kg PO q12h for 14 days). Urine cultures were obtained at days 0, 10, and 21. Microbiologic and clinical cure rates were evaluated 7 days after antimicrobial treatment was discontinued. Lower urinary tract signs and adverse events also were recorded.ResultsThere were 35 dogs in group 1 and 33 in group 2. The microbiologic cure rate was 77.1 and 81.2% for groups 1 and 2, respectively. The clinical cure rate was 88.6 and 87.9% for groups 1 and 2, respectively. Cure rates between groups did not differ according to the selected margin of noninferiority.Conclusions and clinical importanceHDSD enrofloxacin treatment was not inferior to a conventional amoxicillin-clavulanic acid protocol for the treatment of uncomplicated bacterial UTI in dogs. Further research is warranted to determine if this protocol will positively impact owner compliance and decrease the emergence of antimicrobial resistance

Excitation spectrum of bosons in a finite one-dimensional circular waveguide via the Bethe ansatz

The exactly solvable Lieb-Liniger model of interacting bosons in one-dimension has attracted renewed interest as current experiments with ultra-cold atoms begin to probe this regime. Here we numerically solve the equations arising from the Bethe ansatz solution for the exact many-body wave function in a finite-size system of up to twenty particles for attractive interactions. We discuss the novel features of the solutions, and how they deviate from the well-known string solutions [H. B. Thacker, Rev. Mod. Phys.\ \textbf{53}, 253 (1981)] at finite densities. We present excited state string solutions in the limit of strong interactions and discuss their physical interpretation, as well as the characteristics of the quantum phase transition that occurs as a function of interaction strength in the mean-field limit. Finally we compare our results to those of exact diagonalization of the many-body Hamiltonian in a truncated basis. We also present excited state solutions and the excitation spectrum for the repulsive 1D Bose gas on a ring.Comment: 13 pages, 12 figure

StudySnap

In today’s modern education world, there have been several emerging technologies that were created to expand the learning experience beyond the traditional pencil and paper. Such items include online planners and numerous online student resource websites, but some students may find that there are sometimes too many resources. With so many resources available to them, students may find it overwhelming and may not even know where to start when it comes time to study. StudySnap aims to solve the unorganized and cluttered nature of study time by combining a clean resource organization tool with a smart and automatic resource search engine that provides students with resources created by their peers that are specifically tailored to their needs. Using various cloud computing services, natural language processing techniques, and Optical Character Recognition (OCR), students will be able to access a variety of notes about various topics. The system will analyze the user’s interests or needs, and help find resources posted by other students that are specifically related to those needs. The user will then be able to select which notes they like, and view and rate the notes as needed. The goal is that by providing an all-in-one study system, students can remove some of the clutter that traditionally comes with studying and help get them the marks they are looking for

Complex-Temperature Singularities in the d=2d=2 Ising Model. III. Honeycomb Lattice

We study complex-temperature properties of the uniform and staggered susceptibilities $\chi$ and $\chi^{(a)}$ of the Ising model on the honeycomb lattice. From an analysis of low-temperature series expansions, we find evidence that $\chi$ and $\chi^{(a)}$ both have divergent singularities at the point $z=-1 \equiv z_{\ell}$ (where $z=e^{-2K}$), with exponents $\gamma_{\ell}'= \gamma_{\ell,a}'=5/2$. The critical amplitudes at this singularity are calculated. Using exact results, we extract the behaviour of the magnetisation $M$ and specific heat $C$ at complex-temperature singularities. We find that, in addition to its zero at the physical critical point, $M$ diverges at $z=-1$ with exponent $\beta_{\ell}=-1/4$, vanishes continuously at $z=\pm i$ with exponent $\beta_s=3/8$, and vanishes discontinuously elsewhere along the boundary of the complex-temperature ferromagnetic phase. $C$ diverges at $z=-1$ with exponent $\alpha_{\ell}'=2$ and at $v=\pm i/\sqrt{3}$ (where $v = \tanh K$) with exponent $\alpha_e=1$, and diverges logarithmically at $z=\pm i$. We find that the exponent relation $\alpha'+2\beta+\gamma'=2$ is violated at $z=-1$; the right-hand side is 4 rather than 2. The connections of these results with complex-temperature properties of the Ising model on the triangular lattice are discussed.Comment: 22 pages, latex, figures appended after the end of the text as a compressed, uuencoded postscript fil

Fair game: exploring the dynamics, perception and environmental impact of ‘surplus’ wild foods in England 10kya-present

This paper brings together zooarchaeological data from Neolithic to Post-medieval sites in England to explore the plasticity of cultural attitudes to the consumption of wild animals. It shows how, through time, game has been considered variously as ‘tabooed’ and ‘edible’, each having implications for patterns of biodiversity and wildlife management. The essential points being made are that deeper-time studies can reveal how human perceptions of ‘surplus foods’ have the potential to both create and remedy problems of environmental sustainability and food security. Perhaps more significantly, this paper argues that understanding the bio-cultural past of edible wild animal species has the potential to transform human attitudes to game in the present. This is important at a time when food security and the production of surplus are pressing national and global concerns

Doing public health differently: How can public health departments engage with local communities through social media interventions?

Objectives This paper evaluates a collaborative intervention between public health professionals and local social media administrators, in which the social media site Facebook was used with a view to strengthening engagement with and, dissemination of, core messages and building trust and resilience within local communities during the COVID-19 pandemic. Study design A qualitative design was used, exploring the research question: how does collaboration between public health professionals and local social network group administrators create community engagement during a global crisis? Methods Fourteen semi-structured interviews were conducted with public health staff and online group administrators. Data was analysed using framework analysis. Results Collaboration between public health professionals and local group administrators created both opportunities and challenges. Local group administrators had wide reach and trust within the local community, but message credibility was enhanced through local authority involvement. Such collaborations contain inherent tensions due to perceived risks to social capital and independence but can be successful if receiving strong risk-tolerant support from the local authority. Findings are discussed in the context of Bourdieu's theory of social capital to examine how public health information can be delivered by trusted social media actors in communication tailored to the local community. Conclusions Social media provides new channels of communication for delivery of public health messages, enabling new ways of working which create long-term engagement and community building. Although the intervention was developed quickly in response to the COVID-19 pandemic, participants felt it could be mobilised to address a wider range of issues