Citizen science is an increasingly popular way of engaging volunteers in the collection of scientific data. Despite this, data quality remains a concern and there is little published evidence about the accuracy of records generated by citizen scientists. Here we compare data generated by two British citizen science projects, Blooms for Bees and BeeWatch, to determine the ability of volunteer recorders to identify bumblebee ( Bombus ) species. We assessed recorders’ identification ability in two ways–as recorder accuracy (the proportion of expert-verified records correctly identified by recorders) and recorder success (the proportion of recorder-submitted identifications confirmed correct by verifiers). Recorder identification ability was low (<50% accuracy; <60% success), despite access to project specific bumblebee identification materials. Identification ability varied significantly depending on bumblebee species, with recorders most able to correctly identify species with distinct appearances. Blooms for Bees recorders (largely recruited from the gardening community) were markedly less able to identify bumblebees than BeeWatch recorders (largely individuals with a more specific interest in bumblebees). Within both projects, recorders demonstrated an improvement in identification ability over time. Here we demonstrate and quantify the essential role of expert verification within citizen science projects, and highlight where resources could be strengthened to improve recorder ability.

Intracellular replication within specialized vacuoles and cell-to-cell spread in the tissue are essential for the virulence of Salmonella enterica. By observing infection dynamics at the single-cell level in vivo, we have discovered that the Salmonella pathogenicity island 2 (SPI-2) type 3 secretory system (T3SS) is dispensable for growth to high intracellular densities. This challenges the concept that intracellular replication absolutely requires proteins delivered by SPI-2 T3SS, which has been derived largely by inference from in vitro cell experiments and from unrefined measurement of net growth in mouse organs. Furthermore, we infer from our data that the SPI-2 T3SS mediates exit from infected cells, with consequent formation of new infection foci resulting in bacterial spread in the tissues. This suggests a new role for SPI-2 in vivo as a mediator of bacterial spread in the body. In addition, we demonstrate that very similar net growth rates of attenuated salmonellae in organs can be derived from very different underlying intracellular growth dynamics.

Citizen science is the involvement of citizens, such as farmers, in the research process. Citizen science has become increasingly popular recently, supported by the proliferation of mobile communication technologies such as smartphones. However, citizen science methodologies have not yet been widely adopted in agricultural research. Here, we conducted an online survey with 57 British and French farmers in 2014. We investigated (1) farmer ownership and use of smartphone technologies, (2) farmer use of farmspecific management apps, and (3) farmer interest and willingness to participate in agricultural citizen science projects. Our results show that 89 % respondents owned a smartphone, 84 % used it for farm management, and 72 % used it on a daily basis. Fifty-nine percent engaged with farm-specific apps, using on average four apps. Ninety-three percent respondents agreed that citizen science was a useful methodology for data collection, 93 % for real-time monitoring, 83 % for identification of research questions, 72 % for experimental work, and 72 % for wildlife recording. Farmers also showed strong interest to participate in citizen science projects, often willing to commit substantial amounts of time. For example, 54 % of British respondents were willing to participate in farmland wildlife recording once a week or monthly. Although financial support was not always regarded as necessary, experimental work was the most likely activity for which respondents thought financial support would be essential. Overall, this is the first study to quantify and explore farmers' use of smartphones for farm management, and document strong support for farm-based citizen science projects.

Background Closure of an abdominal stoma, a common elective operation, is associated with frequent complications; one of the commonest and impactful is incisional hernia formation. We aimed to investigate whether biological mesh (collagen tissue matrix) can safely reduce the incidence of incisional hernias at the stoma closure site. Methods In this randomised controlled trial (ROCSS) done in 37 hospitals across three European countries (35 UK, one Denmark, one Netherlands), patients aged 18 years or older undergoing elective ileostomy or colostomy closure were randomly assigned using a computer-based algorithm in a 1:1 ratio to either biological mesh reinforcement or closure with sutures alone (control). Training in the novel technique was standardised across hospitals. Patients and outcome assessors were masked to treatment allocation. The primary outcome measure was occurrence of clinically detectable hernia 2 years after randomisation (intention to treat). A sample size of 790 patients was required to identify a 40% reduction (25% to 15%), with 90% power (15% drop-out rate). This study is registered with ClinicalTrials.gov, NCT02238964.

SummaryGrowth of Salmonella enterica in mammalian tissues results from continuous spread of bacteria to new host cells. Our previous work indicated that infective S. enterica are liberated from host cells via stochastic necrotic burst independently of intracellular bacterial numbers. Here we report that liver phagocytes can undergo apoptotic caspase-3-mediated cell death in vivo, with apoptosis being a rare event, more prevalent in heavily infected cells. The density-dependent apoptotic cell death is likely to constitute an alternative mechanism of bacterial spread as part of a bet-hedging strategy, ensuring an ongoing protective intracellular environment in which some bacteria can grow and persist.

SummaryAntibodies play an important role in immunity to Salmonella enterica. Here we evaluated the requirement for Fcc receptors in host resistance to S. enterica using an in vivo model of systemic infection. We show that mice lacking FccRI, II and III can control and clear a primary infection with S. enterica micro-organisms of low virulence, but are impaired in the expression of vaccine-induced acquired immunity to oral challenge with virulent bacteria. We also show that, in vivo, FccRI, II, III )/) mice were able to mount efficient T-helper 1 type T-cell responses and antibody responses specific for S. enterica. The work indicates that targeting S. enterica to FccR is needed for the expression of vaccine-induced acquired immunity, but is not essential for the engenderment of T-and B-cell immunity to the bacterium in vivo.

Bacteria of the species Salmonella enterica cause a range of life-threatening diseases in humans and animals worldwide. The within-host quantitative, spatial, and temporal dynamics of S. enterica interactions are key to understanding how immunity acts on these infections and how bacteria evade immune surveillance. In this study, we test hypotheses generated from mathematical models of in vivo dynamics of Salmonella infections with experimental observation of bacteria at the single-cell level in infected mouse organs to improve our understanding of the dynamic interactions between host and bacterial mechanisms that determine net growth rates of S. enterica within the host. We show that both bacterial and host factors determine the numerical distributions of bacteria within host cells and thus the level of dispersiveness of the infection.Bacteria of the species Salmonella enterica are a threat to public health, causing enteric systemic diseases (typhoid and paratyphoid fever), gastroenteritis and nontyphoidal septicemia in humans and similar diseases in many other animal species worldwide. The emergence of multidrug-resistant Salmonella strains and the insufficient efficacy of some of the currently available Salmonella vaccines highlight the urgent need for improved prevention strategies to combat salmonellosis in humans and animals.S. enterica typhoidal infections have a truly dispersive nature. In mouse infections, the clonal and independent expansion of bacteria derived from the initial inoculum is paralleled by an increase in the number of infected cells and of the multicellular pathological lesions that form at foci of infection (11,15,16). Control of the growth and spread of the bacteria requires recruitment and activation of phagocytes at the foci of infection with an influx of bone marrow-derived cells into the tissues and the concerted action of key cytokine networks: tumor necrosis factor alpha, gamma interferon (IFN-␥), and interleukin-12 (IL-12), . In addition, reactive oxygen intermediates and reactive nitrogen intermediates act in phagocytes to control the growth of ingested bacteria (10,17).A key feature of the spread of S. enterica in the tissues is the heterogeneous numerical distribution of intracellular bacteria with low bacterial numbers seen at any one time in the majority of infected phagocytes, while a minority of phagocytes can be heavily infected (16). The combination of intracellular bacterial distributional data with "branching process" mathematical models allowed the discrimination of a number of mechanistic hypotheses on the cause of this strikingly skewed distribution of bacteria among host cells (1). In particular, the analysis gave scant support to the hypothesis that highly infected cells were intrinsically more susceptible to infection. Rather, the model supported the idea that all phagocytes were equivalently susceptible and that the skewed distribution was generated by the epidemic spread of the bacteria through the host cell population. The model gave further discrimination at ...

There is increasing interest in the value of domestic gardens for supporting biodiversity. While it is well established that bumblebees exploit urban green spaces, this is the first study to explore the land use and floral preferences of the UK's seven most common bumblebees in gardens and allotments cultivated for food. A citizen science survey was carried out at 38 sites, between 1st June and 30th September 2013. At the landscape scale, bumblebee abundance and species richness was not significantly correlated with surrounding land use characteristics (both p>0.05). Bombus pratorum was the only species to show correlations with surrounding land use, demonstrating a positive relationship with built areas and gardens and allotments, and a negative correlation with greenspace and agriculture. At the local site-level scale, bumblebee abundance was negatively correlated with areas cultivated for vegetables and fruits, and positively correlated with areas cultivated for flowers, although neither correlation was statistically significant (p=0.070 and p=0.051 respectively). Bumblebee species richness was not correlated with either land use (P>0.05). All bumblebee species were negatively correlated with areas cultivated for vegetables and fruit, bare ground and hard paving. Several flowering plants were visited by all bumblebee species, although relative preferences varied between bumblebee species. Results emphasise the importance of including floral resources within garden and allotment areas cultivated for food, and the need for a mosaic of different flowering plants to cater for varying floral preferences demonstrated by bumblebee species.