92 research outputs found
Living in the slow or fast lane: cognitive phenotypes in honeybees
2021 Spring.Includes bibliographical references.The evolution and maintenance of cognitive variation is a question of fundamental interest in animal behavior because differences in cognition are predicted to underlie differences in behavior. The correlation between behavioral and cognitive variation has largely been conceptualized in terms of the speed-accuracy trade-off driving alternative cognitive strategies where 'fast' individuals are superficial learners that make inaccurate, risk-prone decisions relative to 'slow' individuals. My research has explored the factors that select for different cognitive abilities across species and the mechanisms that maintain variation in cognitive ability within species. To address these questions, I have identified how individuals of four honeybee species (Apis mellifera, A. cerana, A. dorsata, A. florea) differ in performance on multiple cognitive tasks and explored how such variation translates to behavioral outcomes and is shaped by ecology. In chapter one, I tested for the presence of variation in two different learning abilities in honeybee foragers and whether any component of learning influenced wing damage, an indicator of survival. My results demonstrated considerable interindividual variation in different types of learning abilities such that landmark and olfactory learning were negatively correlated. Additionally, I found that olfactory learning was positively correlated with maneuverability performance during flight, a measure which in turn positively influenced wing damage, a proxy for survival. This experiment demonstrated that individuals differ considerably in how they perform on two cognitive tasks and that cognitive ability has important implications for behaviors associated with survival. This work was further explored in chapter 2, where I studied how differences in learning preference relate to decision making during foraging. I measured individual latency to learn on a solitary foraging task and latency to learn on a social foraging task and found that individuals that perform well in a solitary learning task perform poorly in a social learning task. These findings suggest that honeybees specialize in one type of learning strategy when making foraging decisions, and such differences may have important implications for how individuals provision their colony. The first two chapters focused on how differences in performance on cognitive tasks may represent a trade-off that correlates to different behaviors. In the latter half of my dissertation, I first used multiple cognitive traits to define a cognitive phenotype in an individual and then investigated how such differences might impact performance on multiple behaviors and life history traits to determine functional consequences of cognitive variation. I then expanded this research to determine how differences in ecology shape cognitive phenotypes. In chapter three, I tested for the presence of distinct cognitive phenotypes in A. mellifera foragers by measuring multiple cognitive traits and determining whether these traits covary to produce distinct slow and fast cognitive phenotypes. I then compared performance on multiple behavioral and life history tasks to see if there were functional differences between these cognitive types. My results indicate the presence of two cognitive phenotypes that meet the predictions of the speed-accuracy trade-off and that are conserved across colonies. Compared to slow bees, fast bees were described by high associative learning, high preference for novelty and high preference for variance, bees which also engage in more nursing behavior and transition to becoming a forager at an earlier age. In chapter four, which explored how ecological and life history differences shape cognitive phenotypes between closely related honeybee species, I tested for differences in the cognitive phenotype in four honeybee species, each of which occupied a unique ecological niche that was correlated to their position on the slow-fast life history axis. My results indicate that a set of cognitive traits consistently covary within each species, resulting in slow and fast cognitive phenotypes that meet the predictions of the speed-accuracy tradeoff. I also found that the four species do not align on a slow-fast cognitive axis due to known differences in their life history and nesting ecology. Rather, cognitive differences among the species appear correlated to their brain size, which may be driven by differences in foraging range. Taken together, this work indicates that cognitive variation at the individual level has important behavioral and life history outcomes that may impact how the individual interacts with their environment and how the colony performs. At the species level, cognitive variation appears to be driven by a complex relationship with the species unique environment as well as underlying trade-offs associated with costs of cognition
Nurse/midwife-to-patient ratios: a scoping review.
A significant body of work has linked high nurse or midwife workload to negative patient outcomes. Anecdotal reports suggest that mandated ratio models enhance patient care and improve nurse job satisfaction. However, there is limited focused research. To identify key outcomes, implementation processes, and research needs regarding nurse/midwife-to-patient ratios in the Australian healthcare context. Data sources were CINAHL, Open Dissertations, Medline, and Scopus. 289 articles screened, and 53 full text documents independently assessed against criteria by two reviewers and conflicts resolved by a third reviewer, using Covidence™. Three studies were included in this review. Studies focused on nurse (job satisfaction, burnout), patient (mortality, readmission, length of stay) and system (costs) outcomes with limited information on implementation processes and no midwifery research. Ratios provide benefits for patients, nurses, and hospitals although there is limited research in Australia. Implementation was poorly reported
Orally administered extract from \u3ci\u3ePrunella vulgaris\u3c/i\u3e attenuates spontaneous colitis in mdr1a\u3csup\u3e-/-\u3c/sup\u3e mice
AIM: To investigate the ability of a Prunella vulgaris (P. vulgaris) ethanolic extract to attenuate spontaneous typhlocolitis in mdr1a-/- mice.
METHODS: Vehicle (5% ethanol) or P. vulgaris ethanolic extract (2.4 mg/d) were administered daily by oral gavage to mdr1a-/- or wild type FVBWT mice from 6 wk of age up to 20 wk of age. Clinical signs of disease were noted by monitoring weight loss. Mice experiencing weight loss in excess of 15% were removed from the study. At the time mice were removed from the study, blood and colon tissue were collected for analyses that included histological evaluation of lesions, inflammatory cytokine levels, and myeloperoxidase activity.
RESULTS: Administration of P. vulgaris extracts to mdr1a-/- mice delayed onset of colitis and reduced severity of mucosal inflammation when compared to vehicle-treated mdr1a-/- mice. Oral administration of the P. vulgaris extract resulted in reduced (P \u3c 0.05) serum levels of IL-10 (4.6 ± 2 vs 19.4 ± 4), CXCL9 (1319.0 ± 277 vs 3901.0 ± 858), and TNFα (9.9 ± 3 vs 14.8 ± 1) as well as reduced gene expression by more than two-fold for Ccl2, Ccl20, Cxcl1, Cxcl9, IL-1 α, Mmp10, VCAM-1, ICAM, IL-2, and TNFα in the colonic mucosa of mdr1a-/- mice compared to vehicle-treated mdr1a-/- mice. Histologically, several microscopic parameters were reduced (P \u3c 0.05) in P. vulgaris -treated mdr1a-/- mice, as was myeloperoxidase activity in the colon (2.49 ± 0.16 vs 3.36 ± 0.06, P \u3c 0.05). The numbers of CD4+ T cells (2031.9 ± 412.1 vs 5054.5 ± 809.5) and germinal center B cells (2749.6 ± 473.7 vs 4934.0 ± 645.9) observed in the cecal tonsils of P. vulgaris - treated mdr1a-/- were significantly reduced (P \u3c 0.05) from vehicle-treated mdr1a-/- mice. Vehicle-treated mdr1a-/- mice were found to produce serum antibodies to antigens derived from members of the intestinal microbiota, indicative of severe colitis and a loss of adaptive tolerance to the members of the microbiota. These serum antibodies were greatly reduced or absent in P. vulgaris -treated mdr1a-/- mice.
CONCLUSION: The anti-inflammatory activity of P. vulgaris ethanolic extract effectively attenuated the severity of intestinal inflammation in mdr1a-/- mice
Genotypic determinants of fluoroquinolone and macrolide resistance in Neisseria gonorrhoeae.
Background:High rates of antimicrobial resistance (AMR) in Neisseria gonorrhoeae hinder effective treatment, but molecular AMR diagnostics may help address the challenge. This study aimed to appraise the literature for resistance-associated genotypic markers linked to fluoroquinolones and macrolides, to identify and review their use in diagnostics. Methods: Medline and EMBASE databases were searched and data pooled to evaluate associations between genotype and phenotypic resistance. The minimum inhibitory concentration (MIC) cut-offs were ≤ 0.06 mg L-1 for non-resistance to ciprofloxacin and ≤ 0.5 mg L-1 for non-resistance to azithromycin. Results: Diagnostic accuracy estimates were limited by data availability and reporting. It was found that: 1) S91 and D95 mutations in the GyrA protein independently predicted ciprofloxacin resistance and, used together, gave 98.6% (95% confidence interval (CI) 98.0-99.0%) sensitivity and 91.4% (95%CI 88.6-93.7%) specificity; 2) the number of 23S rRNA gene alleles with C2611T or A2059G mutations was highly correlated with azithromycin resistance, with mutation in any allele giving a sensitivity and specificity of 66.1% (95%CI 62.1-70.0%) and 98.9% (95%CI 97.5-99.5%) respectively. Estimated negative (NPV) and positive predictive values (PPV) for a 23S rRNA diagnostic were 98.6% (95%CI 96.8-99.4%) and 71.5% (95%CI 68.0-74.8%) respectively; 3) mutation at amino acid position G45 in the MtrR protein independently predicted azithromycin resistance; however, when combined with 23S rRNA, did not improve the PPV or NPV. Conclusions: Viable candidates for markers of resistance detection for incorporation into diagnostics were demonstrated. Such tests may enhance antibiotic stewardship and treatment options
Reactions to Brexit in images : a multimodal content analysis of shared visual content on Flickr
In this article, the authors analyze citizens’ reactions to Brexit on social media after the referendum results by performing a content analysis of 5877 posts collected from the social media platform Flickr, written in English, German, French, Spanish or Italian. Their research aims to answer the three following questions: What multimodal practices are adopted by citizens when they react to societal events like Brexit? To what extent do these practices illustrate types of citizenship that are specific to social networks? Can we observe different reactions to Brexit according to the languages used by the citizens? The authors focus on the types of visual content the citizens used to react to Brexit, as well as on what types of social relations this content can particularly create between their authors and the other members of the Flick community. Their article also highlights to what extent these posts shared on Flickr show content that is in favour of, or against, Brexit
TREM-2 (triggering receptor expressed on myeloid cells 2) is a phagocytic receptor for bacteria
Phagocytosis, which is essential for the immune response to pathogens, is initiated by specific interactions between pathogens and cell surface receptors expressed by phagocytes. This study identifies triggering receptor expressed on myeloid cells 2 (TREM-2) and its signaling counterpart DAP12 as a molecular complex that promotes phagocytosis of bacteria. Expression of TREM-2–DAP12 enables nonphagocytic Chinese hamster ovary cells to internalize bacteria. This function depends on actin cytoskeleton dynamics and the activity of the small guanosine triphosphatases Rac and Cdc42. Internalization also requires src kinase activity and tyrosine phosphorylation. In bone marrow–derived macrophages, phagocytosis is decreased in the absence of DAP12 and can be restored by expression of TREM-2–DAP12. Depletion of TREM-2 inhibits both binding and uptake of bacteria. Finally, TREM-2–dependent phagocytosis is impaired in Syk-deficient macrophages. This study highlights a novel role for TREM-2–DAP12 in the immune response to bacterial pathogens
Using qualitative research methods in biomedical innovation:the case of cultured red blood cells for transfusion
Background Qualitative research has a key role to play in biomedical innovation projects. This article focuses on the appropriate use of robust social science methodologies (primarily focus group studies) for identifying the public’s willingness and preference for emerging medical technologies. Our study was part of the BloodPharma project (now known as the Novosang project) to deliver industrially generated red blood cells for transfusion. Previous work on blood substitutes shows that the public prefers donated human blood. However, no research has been conducted concerning attitudes to stem cell derived red blood cells. Method Qualitative research methods including interviews and focus groups provide the methodological context for this paper. Results Focus groups were used to elicit views from sub-sections of the UK population about the potential use of such cultured red blood cells. We reflect on the appropriateness of that methodology in the context of the BloodPharma project. Findings are in the form of lessons transferable to other interdisciplinary, science-led teams about what a social science dimension can bring; why qualitative research should be included; and how it can be used effectively. Discussion Qualitative data collection offers the strength of exploring ambivalence and investigating the reasons for views, but not necessarily their prevalence in wider society. The inherent value of a qualitative method, such as focus groups, therefore lies in its ability to uncover new information. This contrasts with a quantitative approach to simply ‘measuring’ public opinion on a topic about which participants may have little prior knowledge. We discuss a number of challenges including: appropriate roles for embedded social scientists and the intricacies of doing upstream engagement as well as some of the design issues and limitations associated with the focus group method
The stb Operon Balances the Requirements for Vegetative Stability and Conjugative Transfer of Plasmid R388
The conjugative plasmid R388 and a number of other plasmids carry an operon, stbABC, adjacent to the origin of conjugative transfer. We investigated the role of the stbA, stbB, and stbC genes. Deletion of stbA affected both conjugation and stability. It led to a 50-fold increase in R388 transfer frequency, as well as to high plasmid loss. In contrast, deletion of stbB abolished conjugation but provoked no change in plasmid stability. Deletion of stbC showed no effect, neither in conjugation nor in stability. Deletion of the entire stb operon had no effect on conjugation, which remained as in the wild-type plasmid, but led to a plasmid loss phenotype similar to that of the R388ΔstbA mutant. We concluded that StbA is required for plasmid stability and that StbA and StbB control conjugation. We next observed the intracellular positioning of R388 DNA molecules and showed that they localize as discrete foci evenly distributed in live Escherichia coli cells. Plasmid instability of the R388ΔΔstbA mutant correlated with aberrant localization of the plasmid DNA molecules as clusters, either at one cell pole, at both poles, or at the cell center. In contrast, plasmid molecules in the R388ΔΔstbB mutant were mostly excluded from the cell poles. Thus, results indicate that defects in both plasmid maintenance and transfer are a consequence of variations in the intracellular positioning of plasmid DNA. We propose that StbA and StbB constitute an atypical plasmid stabilization system that reconciles two modes of plasmid R388 physiology: a maintenance mode (replication and segregation) and a propagation mode (conjugation). The consequences of this novel concept in plasmid physiology will be discussed
Iron, Meat and Health
This article is a summary of the publication “Iron and Health” by the Scientific Advisory Committee on Nutrition (SACN) to the U.K. Government (2010), which reviews the dietary intake of iron and the impact of different dietary patterns on the nutritional and health status of the U.K. population. It concludes that several uncertainties make it difficult to determine dose-response relationships or to confidently characterize the risks associated with iron deficiency or excess. The publication makes several recommendations concerning iron intakes from food, including meat, and from supplements, as well as recommendations for further research
The Targeting of Plasmalemmal Ceramide to Mitochondria during Apoptosis
Ceramide is a key lipid mediator of cellular processes such as differentiation, proliferation, growth arrest and apoptosis. During apoptosis, ceramide is produced within the plasma membrane. Although recent data suggest that the generation of intracellular ceramide increases mitochondrial permeability, the source of mitochondrial ceramide remains unknown. Here, we determine whether a stress-mediated plasmalemmal pool of ceramide might become available to the mitochondria of apoptotic cells. We have previously established annexin A1—a member of a family of Ca2+ and membrane-binding proteins—to be a marker of ceramide platforms. Using fluorescently tagged annexin A1, we show that, upon its generation within the plasma membrane, ceramide self-associates into platforms that subsequently invaginate and fuse with mitochondria. An accumulation of ceramide within the mitochondria of apoptotic cells was also confirmed using a ceramide-specific antibody. Electron microscopic tomography confirmed that upon the formation of ceramide platforms, the invaginated regions of the plasma membrane extend deep into the cytoplasm forming direct physical contacts with mitochondrial outer membranes. Ceramide might thus be directly transferred from the plasma membrane to the mitochondrial outer membrane. It is conceivable that this “kiss-of-death” increases the permeability of the mitochondrial outer membrane thereby triggering apoptosis
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