Spring forth diversity: specialist species contribute to the conservation value of headwater springs and streams at the landscape scale

Headwater springs and streams often occur in relatively remote areas, reducing their exposure to human influences and thus increasing their collective capacity to support high biodiversity. Their aquatic macroinvertebrate communities can include species of conservation interest, some of which are specialists associated with groundwater inputs, low water temperature or temporary flow. However, the inaccessibility of some spring and stream networks has left their communities poorly characterized, limiting our capacity to implement effective conservation strategies. We characterized the biodiversity and conservation value of macroinvertebrate communities in a network of 51 relatively inaccessible and unimpacted headwater spring and stream sites spanning multiple catchments in a single landscape type: the chalk downland of south England. At each site, we kick sampled macroinvertebrate communities and recorded environmental variables, including flow permanence. To represent each community, we calculated taxa richness, coverage-adjusted Hill-Shannon diversity, the local contribution to beta diversity, and an index of richness and species rarity. We used the latter three metrics to rank sites based on their biodiversity and conservation value and analyzed relationships between metrics and environmental variables. We found specialists of springs, cold waters, groundwaters and temporary flow regimes, including rare species of conservation value. Some metrics responded to environmental variables, but top-ranking sites had highly variable environmental characteristics. We highlight the value of individual headwater streams with contrasting characteristics as contributors to ecologically heterogeneous site networks. Our results can inform landscape-scale management strategies that protect headwaters as refuges that support biodiverse communities, including rare species, as they adapt to global change

Living on the edge: predicting invertebrate richness and rarity in disturbance‐prone aquatic–terrestrial ecosystems

Temporal fluctuations in cause the spatial extent of wet and dry habitats to vary in aquatic–terrestrial riverine ecosystems, complicating their biomonitoring. As such, biomonitoring efforts may fail to characterize the species that inhabit such habitats, hampering assessments of their biodiversity and implementation of evidence-informed management strategies. Relationships between the dynamic characteristics of aquatic–terrestrial habitats and their communities are well known. Thus, habitat characteristics may enable estimation of faunal assemblage characteristics such as taxonomic richness, regardless of in-channel water levels. We investigated whether indicators summarizing habitat survey data can predict two metrics representing terrestrial invertebrate assemblages (e.g. taxa richness) in two aquatic–terrestrial habitats: exposed riverine sediments and dry temporary streams. We also compared the performance of unimetric and multimetric habitat indicators in making predictions. In exposed riverine sediments, >88% of predictions were correlated with observed taxa richness and an index of conservation status. Values predicted by exposed riverine sediment samples were correlated with those observed in temporary stream channels with comparable riparian (i.e. largely agricultural) land use, but not those observed in channels with contrasting (i.e. more urban) land use. Unimetric habitat indicators performed similarly to more complex multimetric indicators, with each explaining ≤6% of the variability in taxa richness and the index of conservation status. The different spatial scales at which invertebrates respond to habitat conditions and at which indicators record habitat conditions, and a more comprehensive training dataset that incorporates a full range of habitat conditions (i.e. land use), may improve future predictions. We demonstrate that invertebrate assemblage characteristics can be predicted regardless of in-channel water levels. Agreement between exposed riverine sediment predictions and temporary stream observations suggests that these predictions are transferable among a range of aquatic–terrestrial habitat types, and could thus be widely applied to aid conservation of riverine biodiversity in dynamic aquatic–terrestrial ecosystems

Field evidence for the upwind velocity shift at the crest of low dunes

Wind topographically forced by hills and sand dunes accelerates on the upwind (stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind regime, however, possesses a subtle effect, reported here for the first time from field measurements of near-surface wind velocity over a low dune: the wind velocity close to the surface reaches its maximum upwind of the crest. Our field-measured data show that this upwind phase shift of velocity with respect to topography is found to be in quantitative agreement with the prediction of hydrodynamical linear analysis for turbulent flows with first order closures. This effect, together with sand transport spatial relaxation, is at the origin of the mechanisms of dune initiation, instability and growth.Comment: 13 pages, 6 figures. Version accepted for publication in Boundary-Layer Meteorolog

Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden

We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the δ13C and δ15N values for animal references from Västerås. This research (Bäckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD

Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient

<p>Abstract</p> <p>Background</p> <p><it>Bartonella henselae </it>(<it>B. henselae</it>) is considered a rare cause of granulomatous hepatitis. Due to the fastidious growth characteristics of the bacteria, the limited sensitivity of histopathological stains, and the non-specific histological findings on liver biopsy, the diagnosis of hepatic bartonellosis can be difficult to establish. Furthermore, the optimal treatment of established hepatic bartonellosis remains controversial.</p> <p>Case presentation</p> <p>We present a case of hepatic bartonellosis in an immunocompetent woman who presented with right upper quadrant pain and a five cm right hepatic lobe mass on CT scan. The patient underwent a right hepatic lobectomy. Surgical pathology revealed florid necrotizing granulomatous hepatitis, favoring an infectious etiology. Despite extensive histological and serological evaluation a definitive diagnosis was not established initially. Thirteen months after initial presentation, hepatic bartonellosis was diagnosed by PCR studies from surgically excised liver tissue. Interestingly, the hepatic granulomas persisted and <it>Bartonella henselae </it>was isolated from the patient's enriched blood culture after several courses of antibiotic therapy.</p> <p>Conclusion</p> <p>The diagnosis of hepatic bartonellosis is exceedingly difficult to establish and requires a high degree of clinical suspicion. Recently developed, PCR-based approaches may be required in select patients to make the diagnosis. The optimal antimicrobial therapy for hepatic bartonellosis has not been established, and close follow-up is needed to ensure successful eradication of the infection.</p

Can interventions that aim to decrease Lyme disease hazard at non-domestic sites be effective without negatively affecting ecosystem health? A systematic review protocol

Background Lyme disease (LD) is the most commonly reported, broadly distributed vector-borne disease of the northern temperate zone. It is transmitted by ticks and, if untreated, can cause skin, cardiac, nervous system and musculoskeletal disease. The distribution and incidence of LD is increasing across much of North America and Western Europe. Interventions to decrease exposure to LD hazard by encouraging behavioural change have low acceptance in high risk groups, and a safe, effective human LD vaccine is not presently available. As a result, habitat level interventions to decrease LD hazard itself (i.e. levels of infected ticks) have been proposed. However, some interventions may potentially negatively affect ecosystem health, and consequentially be neither desirable, nor politically feasible. This systematic review will catalogue interventions that aim to reduce LD hazard at non-domestic sites, and examine the evidence supporting those which are unlikely to negatively affect ecosystem health. Methods The review will be carried out in two steps. First, a screening and cataloguing stage will be conducted to identify and characterise interventions to decrease LD hazard at non-domestic sites. Secondly, the subset of interventions identified during cataloguing as unlikely to negatively affect ecosystem health will be investigated. In the screening and cataloguing step literature will be collected through database searching using pre-chosen search strings, hand-searching key journals and reviewing the websites of public health bodies. Further references will be identified by contacting stakeholders and researchers. Article screening and assessment of the likely effects of interventions on ecosystem health will be carried out independently by two reviewers. A third reviewer will be consulted if disagreements arise. The cataloguing step results will be presented in tables. Study quality will then be assessed independently by two reviewers, using adapted versions of established tools developed in healthcare research. These results will be presented in a narrative synthesis alongside tables. Though a full meta-analysis is not expected to be possible, if sub-groups of studies are sufficiently similar to compare, a partial meta-analysis will be carried out

Terrestrial implications for the maritime geoarchaeological resource: A view from the Lower Palaeolithic

Stone tools and faunal remains have been recovered from the English Channel and the North Sea through trawling, dredging for aggregates, channel clearance, and coring. These finds highlight the potential for a maritime Lower Palaeolithic archaeological resource. It is proposed here that any Lower Palaeolithic artefacts, faunal remains, and sediments deposited in the maritime zone during dry, low-stand phases were once (and may still be) contextually similar to their counterparts in the terrestrial Lower Palaeolithic records of north-western Europe. Given these similarities, can interpretive models and analytical frameworks developed for terrestrial archaeology be profitably applied to an assessment of the potential value of any maritime resource? The terrestrial geoarchaeological resource for the Lower Palaeolithic is dominated by artefacts and ecofacts that have been fluvially reworked. The spatio-temporal resolution of these data varies from entire river valleys and marine isotope stages to river channel gravel bar surfaces and decadal timescales, thus supporting a variety of questions and approaches. However, the structure of the terrestrial resource also highlights two fundamental limitations in current maritime knowledge that can restrict the application of terrestrial approaches to any potential maritime resource: (i) how have the repetitive transgressions and regressions of the Middle and Late Pleistocene modified the terrace landforms and sediments associated with the river systems of the English Channel and southern North Sea basins?; and (ii) do the surviving submerged terrace landforms and fluvial sedimentary deposits support robust geochronological models, as is the case with the classical terrestrial terrace sequences? This paper highlights potential approaches to these questions, and concludes that the fluvial palaeogeography, Pleistocene fossils, and potential Lower Palaeolithic artefacts of the maritime geoarchaeological resource can be profitably investigated in future as derived, low-resolution data sets, facilitating questions of colonisation, occupation, demography, and material culture