Resurvey of historical collection sites for Balston’s Pygmy Perch in the South West Linkages Target Area

Balston’s Pygmy Perch (Nannatherina balstoni) is one of the rarest native freshwater fishes endemic to south-western Australia (Morgan et al. 2011, 2014). The species inhabits near-coastal lakes, wetlands and flowing streams, and was historically distributed between the Moore River (north of Perth) and the Angove River (east of Albany) (Morgan et al. 2011, 2014). Numerous anthropogenic stressors including habitat destruction, pollution, river regulation, and water abstraction have resulted in an approximate 31% decline in the distribution, with the species apparently having been extirpated from the Swan Coastal Plain and a number of other systems across its range (Morgan et al. 2014). The contemporary distribution extends from the upper reaches of the Margaret River to the Angove River near Two Peoples Bay (Morgan & Beatty 2003; FFGFHU unpubl. data) (see Figure 1). Remnant populations are highly fragmented within this range (Morgan et al. 2014). In light of its typically low abundance and restricted distribution, N. balstoni has been formally recognised as Vulnerable to extinction under the Commonwealth Government’s Environment Protection and Biodiversity Conservation (EPBC) Act 1999 and is listed under Schedule 1 (“fauna that is rare or is likely to become extinct”) of the Western Australian Government’s Wildlife Conservation Act 1950. Accordingly, this fish is the flagship species of the current project entitled “Protecting threatened fishes in the South West Linkages Target Area”. A thorough review of the historical distribution of N. balstoni was conducted at the outset of this project and has now been published in the scientific literature (see Morgan et al. 2014). To complement this review, one of the project’s primary aims was to resurvey a number of historical collection sites in order to ground-truth the current status of resident N. balstoni populations. The results of this survey should provide valuable data for authorities in developing management and recovery strategies for the conservation of this threatened south-western Australian endemic

Temperature and ac Effects on Charge Transport in Metallic Arrays of Dots

We investigate the effects of finite temperature, dc pulse, and ac drives on the charge transport in metallic arrays using numerical simulations. For finite temperatures there is a finite conduction threshold which decreases linearly with temperature. Additionally we find a quadratic scaling of the current-voltage curves which is independent of temperature for finite thresholds. These results are in excellent agreement with recent experiments on 2D metallic dot arrays. We have also investigated the effects of an ac drive as well as a suddenly applied dc drive. With an ac drive the conduction threshold decreases for fixed frequency and increasing amplitude and saturates for fixed amplitude and increasing frequency. For sudden applied dc drives below threshold we observe a long time power law conduction decay.Comment: 6 pages, 7 postscript figure

Failure to infect laboratory rodent hosts with human isolates of Rodentolepis(= Hymenolepis) nana

Confusion exists over the species status and host-specificity of the tapeworm Rodentolepis (= Hymenolepis) nana. It has been described as one species, R. nana, found in both humans and rodents. Others have identified a subspecies; R. nana var. fraterna, describing it as morphologically identical to the human form but only found in rodents. The species present in Australian communities has never been identified with certainty. Fifty one human isolates of Rodentolepis (= Hymenolepis) nana were orally inoculated into Swiss Q, BALB/c, A/J, CBA/CAH and nude (hypothymic) BALB/c mice, Fischer 344 and Wistar rats and specific pathogen free (SPF) hamsters. Twenty four human isolates of R. nana were cross-tested in flour beetles, Tribolium confusum. No adult worms were obtained from mice, rats or hamsters, even when immunosuppressed with cortisone acetate. Only one of the 24 samples developed to the cysticercoid stage in T. confusum; however, when inoculated into laboratory mice the cysticercoids failed to develop into adult worms. The large sample size used in this study, and the range of techniques employed for extraction and preparation of eggs provide a comprehensive test of the hypothesis that the human strain of R. nana is essentially non-infective to rodents

The Kentucky Noisy Monte Carlo Algorithm for Wilson Dynamical Fermions

We develop an implementation for a recently proposed Noisy Monte Carlo approach to the simulation of lattice QCD with dynamical fermions by incorporating the full fermion determinant directly. Our algorithm uses a quenched gauge field update with a shifted gauge coupling to minimize fluctuations in the trace log of the Wilson Dirac matrix. The details of tuning the gauge coupling shift as well as results for the distribution of noisy estimators in our implementation are given. We present data for some basic observables from the noisy method, as well as acceptance rate information and discuss potential autocorrelation and sign violation effects. Both the results and the efficiency of the algorithm are compared against those of Hybrid Monte Carlo. PACS Numbers: 12.38.Gc, 11.15.Ha, 02.70.Uu Keywords: Noisy Monte Carlo, Lattice QCD, Determinant, Finite Density, QCDSPComment: 30 pages, 6 figure

Rigorous pion-pion scattering lengths from threshold pi N --> pi pi N data

A new evaluation of the universal $\pi\pi$ scattering length relation is used to extract the $\pi\pi$ $s$-wave scattering lengths from threshold pion production data. Previous work has shown that the chiral perturbation series relating threshold pion production to $\pi\pi$ scattering lengths appears to converge well only for the isospin-2 case, giving $a_2 = -0.031\pm 0.007 m_\pi^{-1}$. A model-independent and data-insensitive universal curve then implies $a_0 = 0.235\pm 0.03 m_\pi^{-1}$ for the isospin-0 scattering length.Comment: 13 pages, Latex 2.09, uses epsf.sty. Amended version, including revised postscript figures (3) and added reference. To be published in Physics Letters

Chiral Symmetry and light resonances in hot and dense matter

We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which allows us to analyze the behavior of their associated scattering poles when the system is driven towards chiral symmetry restoration. Medium effects are incorporated in three ways: (a) by thermal corrections of the unitarized scattering amplitudes, (b) by finite nuclear density effects associated to a renormalization of the pion decay constant, and complementarily (c) by extending our calculation of the scalar-isoscalar channel to account for finite nuclear density and temperature effects in a microscopic many-body implementation of pion dynamics. Our results are discussed in connection with several phenomenological aspects relevant for nuclear matter and Heavy-Ion Collision experiments, such as $\rho$ mass scaling vs broadening from dilepton spectra and chiral restoration signals in the $\sigma$ channel. We also elaborate on the molecular nature of $\pi\pi$ resonances.Comment: 14 pages, 14 figures. Contribution to Hard Probes 2008, Illa de A Toxa, Spain, June 8th-14th 200

Short Report: Rotavirus Prevalence in the Primary Care Setting in Nicaragua after Universal Infant Rotavirus Immunization

Nicaragua was the first developing nation to implement universal infant rotavirus immunization with the pentavalent rotavirus vaccine (RV5). Initial studies of vaccine effectiveness in Nicaragua and other developing nations have focused on the prevention of hospitalizations and severe rotavirus diarrhea. However, rotavirus diarrhea is more commonly treated in the primary care setting, with only 1-3% of rotavirus cases receiving hospital care. We measured the prevalence of rotavirus infection in primary care clinics in León, Nicaragua, after introduction of the immunization program. In the post-vaccine period, 3.5% (95% confidence interval = 1.9-5.8) of children seeking care for diarrhea tested positive for rotavirus. A high diversity of rotavirus genotypes was encountered among the few positive samples. In conclusion, rotavirus was an uncommon cause of childhood diarrhea in this primary care setting after implementation of a rotavirus immunization program

Cigarette pack messages about toxic chemicals: A randomised clinical trial

Background The USA can require tobacco companies to disclose information about harmful and potentially harmful chemicals in cigarette smoke, but the impact of these messages is uncertain. We sought to assess the effect of placing messages about toxic chemicals on smokers' cigarette packs. Methods Participants were 719 adult cigarette smokers from California, USA, recruited from September 2016 through March 2017. We randomly assigned smokers to receive either factual messages about chemicals in cigarette smoke and their health harms (intervention) or messages about not littering cigarette butts (control) on the side of their cigarette packs for 3 weeks. The primary trial outcome was intention to quit smoking. Results In intent-to-treat analyses, smokers whose packs had chemical messages did not have higher intentions to quit smoking at the end of the trial than those whose packs had control messages (P=0.56). Compared with control messages, chemical messages led to higher awareness of the chemicals (28% vs 15%, P<0.001) and health harms (60% vs 52%, P=0.02) featured in the messages. In addition, chemical messages led to greater negative affect, thinking about the chemicals in cigarettes and the harms of smoking, conversations about the messages and forgoing a cigarette (all P<0.05). Discussion Chemical messages on cigarette packs did not lead to higher intentions to quit among smokers in our trial. However, chemical messages informed smokers of chemicals in cigarettes and harms of smoking, which directly supports their implementation and would be critical to defending the messages against cigarette company legal challenges. Trial registration number NCT02785484