38 research outputs found
Spontaneous honeybee behaviour is altered by persistent organic pollutants
The effect of environmental pollutants on honeybee behaviour has focused mainly on currently used pesticides. However, honeybees are also exposed to persistent organic pollutants (POPs). The aim of this laboratory based study was to determine if exposure to sublethal field-relevant concentrations of POPs altered the spontaneous behaviour of foraging-age worker honeybees. Honeybees (Apis mellifera) were orally exposed to either a sublethal concentration of the polychlorinated biphenyl (PCB) mixture Aroclor 1254 (100 ng/ml), the organochlorine insecticide lindane (2.91 ng/ml) or vehicle (0.01% DMSO, 0.00015% ethanol in 1M sucrose) for 1–4 days. The frequency of single event behaviours and the time engaged in one of four behavioural states (walking, flying, upside down and stationary) were monitored for 15 min after 1, 2, 3 and 4 days exposure. Exposure to Aroclor 1254 but not lindane increased the frequency and time engaged in honeybee motor activity behaviours in comparison to vehicle. The Aroclor 1254—induced hyperactivity was evident after 1 day of exposure and persisted with repeated daily exposure. In contrast, 1 day of exposure to lindane elicited abdominal spasms and increased the frequency of grooming behaviours in comparison to vehicle exposure. After 4 days of exposure, abdominal spasms and increased grooming behaviours were also evident in honeybees exposed to Aroclor 1254. These data demonstrate that POPs can induce distinct behavioural patterns, indicating different toxicokinetic and toxicodynamic properties. The changes in spontaneous behaviour, particularly the PCB-induced chronic hyperactivity and the associated energy demands, may have implications for colony health
Interspecific variation in non-breeding aggregation: a multi-colony tracking study of two sympatric seabirds
Migration is a widespread strategy for escaping unfavourable conditions during winter, but the extent to which populations that segregate during the breeding season aggregate during the non-breeding season is poorly understood. Low non-breeding season aggregation may be associated with higher likelihood of overlap with threats, but with fewer populations affected, whereas high aggregation may result in a lower probability of exposure to threats, but higher overall severity. We investigated non-breeding distributions and extent of population aggregation in 2 sympatrically breeding auks. We deployed geolocation-immersion loggers on common guillemots Uria aalge and razorbills Alca torda at 11 colonies around the northern UK and tracked their movements across 2 non-breeding seasons (2017-18 and 2018-19). Using 290 guillemot and 135 razorbill tracks, we mapped population distributions of each species and compared population aggregation during key periods of the non-breeding season (post-breeding moult and mid-winter), observing clear interspecific differences. Razorbills were largely distributed in the North Sea, whereas guillemot distributions were spread throughout Scottish coastal waters and the North, Norwegian and Barents Seas. We found high levels of aggregation in razorbills and a strong tendency for colony-specific distributions in guillemots. Therefore, razorbills are predicted to have a lower likelihood of exposure to marine threats, but more severe potential impact due to the larger number of colonies affected. This interspecific difference may result in divergent population trajectories, despite the species sharing protection at their breeding sites. We highlight the importance of taking whole-year distributions into account in spatial planning to adequately protect migratory species.</jats:p
Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution.
The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies
Antibodies against endogenous retroviruses promote lung cancer immunotherapy
B cells are frequently found in the margins of solid tumours as organized follicles in ectopic lymphoid organs called tertiary lymphoid structures (TLS). Although TLS have been found to correlate with improved patient survival and response to immune checkpoint blockade (ICB), the underlying mechanisms of this association remain elusive. Here we investigate lung-resident B cell responses in patients from the TRACERx 421 (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy) and other lung cancer cohorts, and in a recently established immunogenic mouse model for lung adenocarcinoma. We find that both human and mouse lung adenocarcinomas elicit local germinal centre responses and tumour-binding antibodies, and further identify endogenous retrovirus (ERV) envelope glycoproteins as a dominant anti-tumour antibody target. ERV-targeting B cell responses are amplified by ICB in both humans and mice, and by targeted inhibition of KRAS(G12C) in the mouse model. ERV-reactive antibodies exert anti-tumour activity that extends survival in the mouse model, and ERV expression predicts the outcome of ICB in human lung adenocarcinoma. Finally, we find that effective immunotherapy in the mouse model requires CXCL13-dependent TLS formation. Conversely, therapeutic CXCL13 treatment potentiates anti-tumour immunity and synergizes with ICB. Our findings provide a possible mechanistic basis for the association of TLS with immunotherapy response
Group Information Behavioural Norms and the Effective Use of a Collaborative Information System: A Case Study
This research investigated whether Group Information Behavioural Norms (GIBNs) are correlated with the effective use of a collaborative information system. Previous research seeking to conceptualize ‘social influence’ in technology adoption has not attempted to include GIBNs. The dependent variable, ‘Effective Use’, comprised two subjective Effectiveness Judgments and three objective Actual Use measures. A mediating variable, ‘Group Adoption’ (GA) of the information system, was conceived as a behavioural expression of group norms and hypothesized to correlate with both GIBNs and Effective Use. It was also hypothesized that GIBNs would have a stronger relationship with Effective Use than the widely used Technology Acceptance Model (TAM) dimensions of Perceived Usefulness and Perceived Ease of Use.
A mixed-methods case study approach was used because measurement of stable norms in workplace groups was required. A medium-sized engineering firm was chosen, and the collaborative information system studied was Knowledge Forum (KF), an educational research tool that was implemented to promote the exchange of information.
There were both expected and unexpected results. GIBNs outperformed the TAM in explaining all three Actual Use variables, although the TAM was the sole significant correlate for one Effectiveness Judgment variable. Information Sharing and Proactive Information Use had opposite correlations with Effective Use, suggesting the existence of distinct information ‘sharing’ and ‘proactive use’ group norms. In addition, the TAM and GIBNs seem to have complementary influences on Effective Use. GA was unexpectedly observed to have the strongest relationship with Effective Use, having a significant relationship with four of five Effective Use measures. GA was also observed to mediate the TAM but not GIBNs.
The results of a case study cannot be extensively generalized. However, the findings are important in three ways. First, this research provides evidence that GIBNs and the TAM exert complementary influences on Effective Use, and that Effective Use is best explained by also including GA. Second, GA may represent a valuable ‘social influence’ extension to the TAM, as a behavioural expression of group norms for collaborative information systems. Finally, this study illustrates the importance of a multi-dimensional conceptualization of ‘Effective Use’ of an information system.Ph
Patient Hand Hygiene Systematic Review
Background: Nosocomial pathogens may be acquired by patients via their own unclean hands, but there has been relatively little emphasis on patient hand hygiene as a tool for preventing healthcare-associated infections (HAIs).
Aim: To determine the efficacy of patient hand hygiene interventions in reducing HAIs and improving patient hand hygiene rates compared to usual care.
Methods: We conducted a systematic review. Electronic databases and grey literature were searched to August 2014. Experimental and quasi-experimental studies were included if they evaluated a patient hand hygiene intervention conducted in an acute or chronic healthcare facility and included HAI incidence and/or patient hand hygiene rates as an outcome. All steps were performed independently by two investigators.
Findings: Ten studies were included, most of which were uncontrolled before-after studies (n=8). The majority of interventions (n=7) were multimodal, with components similar to healthcare worker hand hygiene programs, including education, reminders, audit and feedback, and provision of hand hygiene products. Six studies reported HAI outcomes and 4 studies assessed patient hand hygiene rates; all demonstrated improvements but were at moderate to high risk of bias.
Conclusion: Interventions to improve patient hand hygiene may reduce the incidence of HAIs and improve hand hygiene rates, but the quality of evidence is low. Future studies should use stronger designs and be more selective in their choice of outcomes.Medicine, Faculty ofNon UBCPathology and Laboratory Medicine, Department ofReviewedFacult