Salmon-derived nitrogen in terrestrial invertebrates from coniferous forests of the Pacific Northwest

BACKGROUND: Bi-directional flow of nutrients between marine and terrestrial ecosystems can provide essential resources that structure communities in transitional habitats. On the Pacific coast of North America, anadromous salmon (Oncorhynchus spp.) constitute a dominant nutrient subsidy to aquatic habitats and riparian vegetation, although the contribution to terrestrial habitats is not well established. We use a dual isotope approach of δ(15)N and δ(13)C to test for the contribution of salmon nutrients to multiple trophic levels of litter-based terrestrial invertebrates below and above waterfalls that act as a barrier to salmon migration on two watersheds in coastal British Columbia. RESULTS: Invertebrates varied predictably in δ(15)N with enrichment of 3–8‰ below the falls compared with above the falls in all trophic groups on both watersheds. We observed increasing δ(15)N levels in our invertebrate groups with increasing consumption of dietary protein. Invertebrates varied in δ(13)C but did not always vary predictably with trophic level or habitat. From 19.4 to 71.5% of invertebrate total nitrogen was originally derived from salmon depending on taxa, watershed, and degree of fractionation from the source. CONCLUSIONS: Enrichment of δ(15)N in the invertebrate community below the falls in conjunction with the absence of δ(13)C enrichment suggests that enrichment in δ(15)N occurs primarily through salmon-derived nitrogen subsidies to litter, soil and vegetation N pools rather than from direct consumption of salmon tissue or salmon tissue consumers. Salmon nutrient subsidies to terrestrial habitats may result in shifts in invertebrate community structure, with subsequent implications for higher vertebrate consumers, particularly the passerines

Hydrodynamic theory of de-wetting

A prototypical problem in the study of wetting phenomena is that of a solid plunging into or being withdrawn from a liquid bath. In the latter, de-wetting case, a critical speed exists above which a stationary contact line is no longer sustainable and a liquid film is being deposited on the solid. Demonstrating this behavior to be a hydrodynamic instability close to the contact line, we provide the first theoretical explanation of a classical prediction due to Derjaguin and Levi: instability occurs when the outer, static meniscus approaches the shape corresponding to a perfectly wetting fluid

Topological constraints on spiral wave dynamics in spherical geometries with inhomogeneous excitability

We analyze the way topological constraints and inhomogeneity in the excitability influence the dynamics of spiral waves on spheres and punctured spheres of excitable media. We generalize the definition of an index such that it characterizes not only each spiral but also each hole in punctured, oriented, compact, two-dimensional differentiable manifolds and show that the sum of the indices is conserved and zero. We also show that heterogeneity and geometry are responsible for the formation of various spiral wave attractors, in particular, pairs of spirals in which one spiral acts as a source and a second as a sink -- the latter similar to an antispiral. The results provide a basis for the analysis of the propagation of waves in heterogeneous excitable media in physical and biological systems.Comment: 5 pages, 6 Figures, major revisions, accepted for publication in Phys. Rev.

Urea Applied to Puccinellia-Based Pastures Increases Pasture and Sheep Production

In the 1950\u27s large areas of native vegetation in the upper south east of South Australia (SA) were replaced with highly productive Hunter River lucerne. This maintained groundwater recharge at near pre-clearing levels. The area of lucerne was reduced dramatically in the late 1970\u27s by a combination of lucerne aphids, wingless grasshoppers and drought. In 1981 severe flooding inundated large areas of the region, causing the saline groundwater to rise to the soil surface. Since that time, dryland salinity has been a feature of the local farming system and salt-tolerant pastures based on puccinellia (Puccinellia ciliata) were widely established. Despite this, few agronomic studies have been conducted on puccinellia to enable management guidelines to be determined. The aim of this experiment was to compare animal and pasture production on volunteer saline pasture and improved saline pasture with and without fertiliser inputs

Disjoining Potential and Spreading of Thin Liquid Layers in the Diffuse Interface Model Coupled to Hydrodynamics

The hydrodynamic phase field model is applied to the problem of film spreading on a solid surface. The disjoining potential, responsible for modification of the fluid properties near a three-phase contact line, is computed from the solvability conditions of the density field equation with appropriate boundary conditions imposed on the solid support. The equation describing the motion of a spreading film are derived in the lubrication approximation. In the case of quasi-equilibrium spreading, is shown that the correct sharp-interface limit is obtained, and sample solutions are obtained by numerical integration. It is further shown that evaporation or condensation may strongly affect the dynamics near the contact line, and accounting for kinetic retardation of the interphase transport is necessary to build up a consistent theory.Comment: 14 pages, 5 figures, to appear in PR

Development of a chicken 5 K microarray targeted towards immune function

<p>Abstract</p> <p>Background</p> <p>The development of microarray resources for the chicken is an important step in being able to profile gene expression changes occurring in birds in response to different challenges and stimuli. The creation of an immune-related array is highly valuable in determining the host immune response in relation to infection with a wide variety of bacterial and viral diseases.</p> <p>Results</p> <p>Here we report the development of chicken immune-related cDNA libraries and the subsequent construction of a microarray containing 5190 elements (in duplicate). Clones on the array originate from tissues known to contain high levels of cells related to the immune system, namely Bursa, Peyers patch, thymus and spleen. Represented on the array are genes that are known to cluster with existing chicken ESTs as well as genes that are unique to our libraries. Some of these genes have no known homologies and represent novel genes in the chicken collection. A series of reference genes (ie. genes of known immune function) are also present on the array. Functional annotation data is also provided for as many of the genes on the array as is possible.</p> <p>Conclusion</p> <p>Six new chicken immune cDNA libraries have been created and nearly 10,000 sequences submitted to GenBank [GenBank: <ext-link ext-link-type="gen" ext-link-id="AM063043">AM063043</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM071350">AM071350</ext-link>; <ext-link ext-link-type="gen" ext-link-id="AM071520">AM071520</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM072286">AM072286</ext-link>; <ext-link ext-link-type="gen" ext-link-id="AM075249">AM075249</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM075607">AM075607</ext-link>]. A 5 K immune-related array has been developed from these libraries. Individual clones and arrays are available from the ARK-Genomics resource centre.</p

Sex and sport: chlamydia screening in rural sporting clubs

BACKGROUND: Chlamydia trachomatis is the most common notifiable disease in Australia, mainly affecting those aged 15 to 29 years. Testing rates are low in Australia and considerably lower in rural areas, with access and confidentiality of sexual health services being problematic in rural and regional areas. This study aimed to determine the feasibility of establishing a pilot chlamydia testing outreach program among 16-25 year old males and females in rural Victoria (Australia) undertaken at local sporting clubs and to determine the prevalence of chlamydia and acceptability of the program in this population. METHODS: We aimed to recruit young people from the Loddon Mallee region of Victoria, Australia between May and September 2007. After a night of sporting practice, participants provided a first pass urine sample, completed a brief questionnaire regarding risk taking behaviour and were then provided with condoms and health promotion materials about sexually transmitted infections (STIs). Those positive for chlamydia were managed by telephone consultation with a practitioner from Melbourne Sexual Health Centre. RESULTS: A total of 709 young people participated (77% male, 23% female), 77% being sexually active. All provided a urine sample and completed the questionnaire. Participation rate on recruitment nights was over 95%. Overall chlamydia prevalence in those sexually active was 5.1% (95%CI: 3.4-7.3), 7.4% in females (95%CI: 3.5-13.6) and 4.5% in males (95%CI: 2.7-6.9). CONCLUSION: Sporting clubs represent a feasible, acceptable and innovative community based setting to screen, treat and educate young people in a rural and regional setting, especially for males

Wave activity (planetary, tidal) throughout the middle atmosphere (20-100km) over the CUJO network: Satellite (TOMS) and Medium Frequency (MF) radar observations

Planetary and tidal wave activity in the tropopause-lower stratosphere and mesosphere-lower thermosphere (MLT) is studied using combinations of ground-based (GB) and satellite instruments (2000-2002). The relatively new MFR (medium frequency radar) at Platteville (40&amp;deg; N, 105&amp;deg; W) has provided the opportunity to create an operational network of middle-latitude MFRs, stretching from 81&amp;deg; W-142&amp;deg; E, which provides winds and tides 70-100km. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43&amp;deg; N, 81&amp;deg; W), Platteville (40&amp;deg; N, 105&amp;deg; W), Saskatoon (52&amp;deg; N, 107&amp;deg; W), Wakkanai (45&amp;deg; N, 142&amp;deg; E) and Yamagawa (31&amp;deg; N, 131&amp;deg; E). It offers a significant 7000-km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14&amp;deg;) at two longitudes. Satellite data mainly involve the daily values of the total ozone column measured by the Earth Probe (EP) TOMS (Total Ozone Mapping Spectrometer) and provide a measure of tropopause-lower stratospheric planetary wave activity, as well as ozone variability. &lt;P style=&quot;line-height: 20px;&quot;&gt; Climatologies of ozone and winds/tides involving frequency versus time (wavelet) contour plots for periods from 2-d to 30-d and the interval from mid 2000 to 2002, show that the changes with altitude, longitude and latitude are very significant and distinctive. Geometric-mean wavelets for the region of the 40&amp;deg; N MFRs demonstrate occasions during the autumn, winter and spring months when there are similarities in the spectral features of the lower atmosphere and at mesopause (85km) heights. Both direct planetary wave (PW) propagation into the MLT, nonlinear PW-tide interactions, and disturbances in MLT tides associated with fluctuations in the ozone forcing are considered to be possible coupling processes. The complex horizontal wave numbers of the longer period oscillations are provided in frequency contour plots for the TOMS satellite data to demonstrate the differences between lower atmospheric and MLT wave motions and their directions of propagation

Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population

Acknowledgements Generation Scotland has received core funding from the Chief Scientist Office of the Scottish Government Health Directorates CZD/16/6 and the Scottish Funding Council HR03006. We are grateful to all the families who took part, the general practitioners and the Scottish School of Primary Care for their help in recruiting them and the whole Generation Scotland team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists, health-care assistants and nurses. We acknowledge with gratitude the financial support received for this work from the Dr Mortimer and Theresa Sackler Foundation. For the Lothian Birth Cohorts (LBC1921 and LBC1936), we thank Paul Redmond for database management assistance; Alan Gow, Martha Whiteman, Alison Pattie, Michelle Taylor, Janie Corley, Caroline Brett and Caroline Cameron for data collection and data entry; nurses and staff at the Wellcome Trust Clinical Research Facility, where blood extraction and genotyping was performed; staff at the Lothian Health Board; and the staff at the SCRE Centre, University of Glasgow. The research was supported by a program grant from Age UK (Disconnected Mind) and by grants from the Biotechnology and Biological Sciences Research Council (BBSRC). The work was undertaken by The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (MR/K026992/1). Funding from the Medical Research Council (MRC) and BBSRC is gratefully acknowledged. DJM is an NRS Career Research Fellow funded by the CSO. BATS were funded by the Australian Research Council (A79600334, A79906588, A79801419, DP0212016, DP0664638, and DP1093900) and the National Health and Medical Research Council (389875) Australia. MKL is supported by a Perpetual Foundation Wilson Fellowship. SEM is supported by a Future Fellowship (FT110100548) from the Australian Research Council. GWM is supported by a National Health and Medical Research Council (NHMRC), Australia, Fellowship (619667). We thank the twins and siblings for their participation, Marlene Grace, Ann Eldridge and Natalie Garden for cognitive assessments, Kerrie McAloney, Daniel Park, David Smyth and Harry Beeby for research support, Anjali Henders and staff in the Molecular Epidemiology Laboratory for DNA sample processing and preparation and Scott Gordon for quality control and management of the genotypes. This work is supported by a Stragetic Award from the Wellcome Trust, reference 104036/Z/14/Z.Peer reviewedPublisher PD