Crown rust, caused by
Puccinia coronata
f. sp.
avenae
(
Pca
), is a significant impediment to global oat production. Some 98 alleles at 92 loci conferring resistance to
Pca
in
Avena
have been ...designated; however, allelic relationships and chromosomal locations of many of these are unknown. Long-term monitoring of
Pca
in Australia, North America and elsewhere has shown that it is highly variable even in the absence of sexual recombination, likely due to large pathogen populations that cycle between wild oat communities and oat crops. Efforts to develop cultivars with genetic resistance to
Pca
began in the 1950s. Based almost solely on all all-stage resistance, this has had temporary benefits but very limited success. The inability to eradicate wild oats, and their common occurrence in many oat growing regions, means that future strategies to control
Pca
must be based on the assumption of a large and variable prevailing pathogen population with high evolutionary potential, even if cultivars with durable resistance are deployed and grown widely. The presence of minor gene, additive APR to
Pca
in hexaploid oat germplasm opens the possibility of pyramiding several such genes to give high levels of resistance. The recent availability of reference genomes for diploid and hexaploid oat will undoubtedly accelerate efforts to discover, characterise and develop high throughput diagnostic markers to introgress and pyramid resistance to
Pca
in high yielding adapted oat germplasm.
Strong tropical storms are known to affect forest structure, composition, and nutrient cycles in both tropical and temperate regions, although our understanding of these effects disproportionally ...comes from regions experiencing much lower cyclone frequency than many forests in the Northwest Pacific. We summarized the effects of typhoons on forest dynamics at Fushan Experimental Forest (FEF) in northeastern Taiwan, which averages 0.49 major typhoons annually, and compared their resistance and resilience to those of forests in other regions. Typhoons cause remarkably few tree falls at FEF; multiple typhoons in 1994 felled only 1.4% of canopy trees, demonstrating high structural resistance. The most important effect of typhoons in this ecosystem is defoliation, which maintains high understory light levels and enhances heterogeneity, sustaining diversity without large canopy gaps. The vulnerability of taller trees to being blown down has resulted in the short-stature FEF (mean canopy height is 10.2 m). As the FEF is P-limited and a large fraction of total annual P export occurs during typhoons, these storms may have the effect of reducing productivity over time. DIN and K⁺ export only remain elevated for days at FEF, in contrast to the several years observed in Puerto Rico. High resilience is also evident in the rapid recovery of leaf area following typhoons. Heavy defoliation and slow decomposition are among the processes responsible for the high resistance and resilience of FEF to typhoon disturbance. These key structural features may emerge in other forest ecosystems if the frequency of major storms increases with climate change.
Campylobacter jejuni, a major cause of bacterial foodborne illnesses, is considered highly susceptible to environmental stresses. In this study, we extensively investigated the stress tolerance of ...121 clinical strains of C. jejuni against 5 stress conditions (aerobic stress, disinfectant exposure, freeze-thaw, heat treatment, and osmotic stress) that this pathogenic bacterium might encounter during foodborne transmission to humans. In contrast to our current perception about high stress sensitivity of C. jejuni, a number of clinical strains of C. jejuni were highly tolerant to multiple stresses. We performed population genetics analysis by using comparative genomic fingerprinting and showed that multistress-tolerant strains of C. jejuni constituted distinct clades. The comparative genomic fingerprinting subtypes belonging to multistress-tolerant clades were more frequently implicated in human infections than those in stress-sensitive clades. We identified unique stress-tolerant C. jejuni clones and showed the role of stress tolerance in human campylobacteriosis.
A number of studies have reported that pathogenic and nonpathogenic foodborne bacteria have the ability to form filaments in microbiological growth media and foods after prolonged exposure to ...sublethal stress or marginal growth conditions. In many cases, nucleoids are evenly spaced throughout the filamentous cells but septa are not visible, indicating that there is a blockage in the early steps of cell division but the mechanism behind filament formation is not clear. The formation of filamentous cells appears to be a reversible stress response. When filamentous cells are exposed to more favorable growth conditions, filaments divide rapidly into a number of individual cells, which may have major health and regulatory implications for the food industry because the potential numbers of viable bacteria will be underestimated and may exceed tolerated levels in foods when filamentous cells that are subjected to sublethal stress conditions are enumerated. Evidence suggests that filament formation under a number of sublethal stresses may be linked to a reduced energy state of bacterial cells. This review focuses on the conditions and extent of filament formation by foodborne bacteria under conditions that are used to control the growth of microorganisms in foods such as suboptimal pH, high pressure, low water activity, low temperature, elevated CO2 and exposure to antimicrobial substances as well as lack a of nutrients in the food environment and explores the impact of the sublethal stresses on the cell's inability to divide.
•Bacteria can form filamentous cells under sublethal stress conditions.•The specific mechanism leading to filament formation may well be different for the different stresses imposed on the cell.•Filamentation may be a result of decreased levels of energy.•Filamentation may lead to an underestimation of health risks.
Bone is a dynamic tissue that is continuously remodeled through the action of formative osteoblasts and resorptive osteoclasts. Chemerin is a secreted protein that activates chemokine-like receptor 1 ...(CMKLR1), a G protein-coupled receptor expressed by various cell types including adipocytes, osteoblasts, mesenchymal stem cells (MSCs), and macrophages. Previously, we identified chemerin as a regulator of adipocyte and osteoblast differentiation of MSCs. Herein we examined the role of chemerin in Lin(-) Sca1(+) c-kit(+) CD34(+) hematopoietic stem cell (HSC) osteoclastogenesis. We found that HSCs expressed both chemerin and CMKLR1 mRNA and secreted chemerin protein into the extracellular media. Neutralization of chemerin with a blocking antibody beginning prior to inducing osteoclast differentiation resulted in a near complete loss of osteoclastogenesis as evidenced by reduced marker gene expression and matrix resorption. This effect was conserved in an independent model of RAW264.7 cell osteoclastogenesis. Reintroduction of chemerin by reversal of neutralization rescued osteoclast differentiation indicating that chemerin signaling is essential to permit HSC differentiation into osteoclasts but following blockade the cells maintained the potential to differentiate into osteoclasts. Mechanistically, neutralization of chemerin blunted the early receptor activator of nuclear factor-kappa B ligand induction of nuclear factor of activated T-cells 2 (NFAT2), Fos, Itgb3, and Src associated with preosteoclast formation. Consistent with a central role for NFAT2, induction or activation of NFAT2 by forced expression or stimulation of intracellular calcium release rescued the impairment of HSC osteoclastogenesis caused by chemerin neutralization. Taken together, these data support a novel autocrine/paracrine role for chemerin in regulating osteoclast differentiation of HSCs through modulating intracellular calcium and NFAT2 expression/activation.
Multivariate random-effects meta-analyses were conducted on 12 years of data from 14 U.S. states to determine the mean yield and test-weight responses of wheat to treatment with propiconazole, ...prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole. All fungicides led to a significant increase in mean yield and test weight relative to the check (D; P < 0.001). Metconazole resulted in the highest overall yield increase, with a D of 450 kg/ha, followed by prothioconazole+tebuconazole (444.5 kg/ha), prothioconazole (419.1 kg/ha), tebuconazole (272.6 kg/ha), and propiconazole (199.6 kg/ha). Metconazole, prothioconazole+tebuconazole, and prothioconazole also resulted in the highest increases in test weight, with D values of 17.4 to 19.4 kg/m3, respectively. On a relative scale, the best three fungicides resulted in an overall 13.8 to 15.0% increase in yield but only a 2.5 to 2.8% increase in test weight. Except for prothioconazole+tebuconazole, wheat type significantly affected the yield response to treatment; depending on the fungicide, D was 110.0 to 163.7 kg/ha higher in spring than in soft-red winter wheat. Fusarium head blight (FHB) disease index (field or plot-level severity) in the untreated check plots, a measure of the risk of disease development in a study, had a significant effect on the yield response to treatment, in that D increased with increasing FHB index. The probability was estimated that fungicide treatment in a randomly selected study will result in a positive yield increase (p+) and increases of at least 250 and 500 kg/ha (p250 and p500, respectively). For the three most effective fungicide treatments (metconazole, prothioconazole+tebuconazole, and prothioconazole) at the higher selected FHB index, p+ was very large (e.g., >or=0.99 for both wheat types) but p500 was considerably lower (e.g., 0.78 to 0.92 for spring and 0.54 to 0.68 for soft-red winter wheat); at the lower FHB index, p500 for the same three fungicides was 0.34 to 0.36 for spring and only 0.09 to 0.23 for soft-red winter wheat.
Enterobacteriaceae comprise food spoilage organisms as well as food-borne pathogens including Escherichia coli. Heat resistance in E. coli was attributed to a genomic island called the locus of heat ...resistance (LHR). This genomic island is also present in several other genera of Enterobacteriaceae, but its function in the enteric pathogens Salmonella enterica and Enterobacter cloacae is unknown. This study aimed to determine the frequency of the LHR in food isolates of E. coli, and its influence on heat resistance in S. enterica and Enterobacter spp. Cell counts of LHR-positive strains of E. coli, S. enterica and E. cloacae were reduced by less than 1, 1, and 4 log (cfu/mL), respectively, after exposure to 60 °C for 5 min, while cell counts of LHR-negative strains of the same species were reduced by more than 7 log (cfu/mL). Introducing an exogenous copy of the LHR into heat-sensitive enteropathogenic E. coli and S. enterica increased heat resistance to a level that was comparable to LHR-positive wild type strains. Cell counts of LHR-positive S. enterica were reduced by less than 1 log(cfu/mL) after heating to 60 °C for 5 min. Survival of LHR-positive strains was improved by increasing the NaCl concentration from 0 to 4%. Cell counts of LHR-positive strains of E. coli and S. enterica were reduced by less than 2 log (cfu/g) in ground beef patties cooked to an internal core temperature of 71 °C. This study indicates that LHR-positive Enterobacteriaceae pose a risk to food safety.
•The sequence of the LHR is conserved in Enterobacteriaceae.•The function of the LHR in providing heat resistance is also conserved.•Increasing NaCl improves the survival of LHR-positive E. coli and S. enterica.•LHR-positive E. coli and S. enterica survive cooking to 71 °C in ground beef.
As more states legalize cannabis for medical and recreational use, people increasingly use cannabis to treat medical conditions and associated symptoms. The prevalence and utility of cannabis for ...cancer-related symptoms may be clarified by examining cannabis use among patients with a common cancer diagnosis. We aimed to determine the prevalence of cannabis use among colorectal cancer (CRC) survivors and its associations with quality of life (QoL) and cancer-related symptomatology.
A cross-sectional survey of patient-reported QoL outcomes and behaviors, including cannabis use, was conducted within the Patient Outcomes To Advance Learning network's (PORTAL) CRC Cohort. The cohort included a population-based sample of healthcare system members ≥18 years old diagnosed with adenocarcinoma of the colon or rectum from 2010 through 2016. We assessed the association between cannabis use and QoL using the European Organization for Research and Treatment of Cancer QLQ-C30 summary score.
Of the 1784 respondents, 293 (16.4%) reported cannabis use following CRC diagnosis. Current tobacco smokers were more likely to use cannabis compared to former or never tobacco smokers (adjusted odds ratio aOR 2.71, 95% confidence interval CI 1.56 to 4.70). Greater alcohol use (> 4 drinks per month versus ≤4 drinks per month) was associated with cannabis use (aOR 2.17, 95% CI 1.65 to 2.85). There was an association between cannabis use and cancer stage at diagnosis, with stage 3 or 4 CRC patients more likely to use cannabis than stage 1 or 2 CRC patients (aOR 1.68, 95% CI 1.25 to 2.25). After adjusting for demographics, medical comorbidities, stage and site of CRC diagnosis, and prescription opioid use, people who used cannabis had significantly lower QoL than people who did not use cannabis (difference of - 6.14, 95% CI - 8.07 to - 4.20).
Among CRC survivors, cannabis use was relatively common, associated with more advanced stages of disease, associated with tobacco and alcohol use, and not associated with better QoL. Clinicians should inquire about cannabis use among their patients and provide evidence-based recommendations for cancer-related symptoms.
The choice to love McMullen, Ashley M
The Lancet (British edition),
11/2021, Letnik:
398, Številka:
10312
Journal Article
Recenzirano
Yet, in her book All About Love: New Visions, feminist writer bell hooks prefers to think of love not as an emotion or feeling, but as an act of will, writing: “I spent years searching for a ...meaningful definition of the word ‘love,’ and was deeply relieved when I found one in psychiatrist M. Scott Peck's classic self-help book The Road Less Traveled, first published in 1978. Since the choice must be made to nurture growth, this definition counters the more widely accepted assumption that we love instinctually… ...competency in narrative practices is not only a necessary skill but a way to advance health equity, advocacy, and healing across differences. Leaders in the fields of narrative medicine and the medical humanities have continuously highlighted the value of these practices in improving empathic engagement, relationships, and wellbeing in health care.
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