41 research outputs found
Riding on the wind: volatile compounds dictate selection of grassland seedlings by snails.
Background and Aims: Seedling herbivory is an important selective filter in many plant communities. The removal of preferred food plants by both vertebrate and, more commonly, invertebrate herbivores can destroy entire seedling cohorts, and consequently dictate plant community assembly. Nevertheless, our understanding of how and why some seedlings are more prone to herbivore attack than their neighbours remains limited. For seedlings, where even minor tissue damage is fatal, avoiding contact with herbivores is probably advantageous and, on this basis, volatile organic compounds (VOCs) are strong candidates to fulfil a primary defensive role. Methods: We quantified seedling selection by snails (Cornu aspersum) for 14 common, European grassland species. Seedling acceptability was subsequently compared with species-specific expression of constitutive secondary defence metabolites (CSDMs), and VOCs to determine their relative influence on seedling selection. Results: We found no relationship between seedling acceptability and CSDMs, but seedling selection was strongly associated with VOC profiles. Monoterpenes (specifically β-ocimene) were identified as likely attractants, while green leaf volatiles (GLVs) (3-hexen-1-ol acetate) were strongly associated with low seedling acceptability. Conclusions: By elucidating a relationship between VOCs and seedling acceptability, we contradict a long-held, but poorly tested, assumption that seedling selection by herbivores in (semi-)natural plant communities centres on CSDMs. Instead, our results corroborate recent work showing how GLVs, including 3-hexen-1-ol acetate, deter crop seedling selection by molluscs. Although our failure to establish any early-ontogenetic relationship between VOCs and CSDMs also suggests that the former do not 'advertise' possession of the latter, we nevertheless reveal the role that VOCs play in defending seedlings against herbivory before lethal damage occurs
Thrombospondin-1 Contributes to Mortality in Murine Sepsis through Effects on Innate Immunity
BACKGROUND:Thrombospondin-1 (TSP-1) is involved in many biological processes, including immune and tissue injury response, but its role in sepsis is unknown. Cell surface expression of TSP-1 on platelets is increased in sepsis and could activate the anti-inflammatory cytokine transforming growth factor beta (TGFβ1) affecting outcome. Because of these observations we sought to determine the importance of TSP-1 in sepsis. METHODOLOGY/PRINCIPAL FINDINGS:We performed studies on TSP-1 null and wild type (WT) C57BL/6J mice to determine the importance of TSP-1 in sepsis. We utilized the cecal ligation puncture (CLP) and intraperitoneal E. coli injection (i.p. E. coli) models of peritoneal sepsis. Additionally, bone-marrow-derived macrophages (BMMs) were used to determine phagocytic activity. TSP-1-/- animals experienced lower mortality than WT mice after CLP. Tissue and peritoneal lavage TGFβ1 levels were unchanged between animals of each genotype. In addition, there is no difference between the levels of major innate cytokines between the two groups of animals. PLF from WT mice contained a greater bacterial load than TSP-1-/- mice after CLP. The survival advantage for TSP-1-/- animals persisted when i.p. E. coli injections were performed. TSP-1-/- BMMs had increased phagocytic capacity compared to WT. CONCLUSIONS:TSP-1 deficiency was protective in two murine models of peritoneal sepsis, independent of TGFβ1 activation. Our studies suggest TSP-1 expression is associated with decreased phagocytosis and possibly bacterial clearance, leading to increased peritoneal inflammation and mortality in WT mice. These data support the contention that TSP-1 should be more fully explored in the human condition
Regulation of type 1 diabetes development and B-cell activation in nonobese diabetic mice by early life exposure to a diabetogenic environment
Microbes, including viruses, influence type 1 diabetes (T1D) development, but many such influences remain undefined. Previous work on underlying immune mechanisms has focussed on cytokines and T cells. Here, we compared two nonobese diabetic (NOD) mouse colonies, NODlow and NODhigh, differing markedly in their cumulative T1D incidence (22% vs. 90% by 30 weeks in females). NODhigh mice harbored more complex intestinal microbiota, including several pathobionts; both colonies harbored segmented filamentous bacteria (SFB), thought to suppress T1D. Young NODhigh females had increased B-cell activation in their mesenteric lymph nodes. These phenotypes were transmissible. Co-housing of NODlow with NODhigh mice after weaning did not change T1D development, but T1D incidence was increased in female offspring of co-housed NODlow mice, which were exposed to the NODhigh environment both before and after weaning. These offspring also acquired microbiota and B-cell activation approaching those of NODhigh mice. In NODlow females, the low rate of T1D was unaffected by cyclophosphamide but increased by PD-L1 blockade. Thus, environmental exposures that are innocuous later in life may promote T1D progression if acquired early during immune development, possibly by altering B-cell activation and/or PD-L1 function. Moreover, T1D suppression in NOD mice by SFB may depend on the presence of other microbial influences. The complexity of microbial immune regulation revealed in this murine model may also be relevant to the environmental regulation of human T1D
Anesthesia advanced circulatory life support
The constellation of advanced cardiac life support (ACLS) events, such as gas embolism, local anesthetic overdose, and spinal bradycardia, in the perioperative setting differs from events in the pre-hospital arena. As a result, modification of traditional ACLS protocols allows for more specific etiology-based resuscitation.
Perioperative arrests are both uncommon and heterogeneous and have not been described or studied to the same extent as cardiac arrest in the community. These crises are usually witnessed, frequently anticipated, and involve a rescuer physician with knowledge of the patient's comorbidities and coexisting anesthetic or surgically related pathophysiology. When the health care provider identifies the probable cause of arrest, the practitioner has the ability to initiate medical management rapidly.
Recommendations for management must be predicated on expert opinion and physiological understanding rather than on the standards currently being used in the generation of ACLS protocols in the community. Adapting ACLS algorithms and considering the differential diagnoses of these perioperative events may prevent cardiac arrest
Tidal and sub-tidal sea level variability at the northern shelf of the Brazilian Northeast Region
Modelling Neglected Tropical Diseases diagnostics: the sensitivity of skin snips for Onchocerca volvulus in near elimination and surveillance settings
What do high performance football coaches need to know about the coach-athlete relationship? Implications for formal coach education
A high-quality coach-athlete (C-A) relationship improves athlete well-being and performance but has been underrepresented in formal coach education. Eleven football coaches, working in some of the highest profile positions in England, were interviewed. We investigate to what extent their formal coach education experiences influenced their understanding of the C-A relationship. We explore their perceptions of the knowledge, relating to the C-A relationship, that could be included in formal coach education courses. Semi-structured interviews were conducted with eleven coaches. Inductive reflexive thematic analysis generated the following five themes; (1) An incongruence between the importance of the C-A relationship and its prominence in coach education (2) Interpersonal competencies and a progressive approach to the C-A relationship (3) Understand the unique needs of high-performance athletes (4) Build a culture conducive to high quality C-A relationships. Findings demonstrate the C-A relationship is underrepresented in the main English FA Coaching Pathway and provides insights into the knowledge that could be incorporated into courses to meet the needs of coaches. Future research should explore the athlete’s perspective, relating to the knowledge coaches require to develop high quality C-A relationships within high-performance football settings
Developing coaches’ knowledge of the athlete-coach relationship through formal coach education: the perceptions of FA Coach Developers
Developing high quality A-C relationships improves both athlete performance and well-being. However, content relating to the A-C relationship has been underrepresented within coach education. The study evaluates how coaches completing the English FA’s UEFA A and B Licenses develop knowledge of the A-C relationship. It does so by drawing on the perspectives of those who design and deliver the courses. Semi structured interviews were completed with nine experienced FA coach developers alongside a document analysis of seven key course documents. Data was analysed through an inductive thematic analysis and five themes were generated; 1.) Coach developers understand the A-C relationship is built on trust, care and hard and soft interpersonal approaches. 2.) The triad of knowledge impacts on the A-C relationship, not just interpersonal knowledge. 3.) The A-C relationship is not meaningfully addressed in the formalised course content. 4.) In situ visits provide an effective medium to develop knowledge of the A-C relationship. 5.) The assessment framework does not align with the formalised course content. Findings demonstrate despite a diversification in content, the A-C relationship is introduced in a superficial manner. Future research should clarify the knowledge coaches require to develop high quality A-C relationships within a high-performance footballing context