Research on the human microbiome has established that commensal and pathogenic bacteria can influence obesity, cancer, and autoimmunity through mechanisms mostly unknown. We found that a component of ...bacterial biofilms, the amyloid protein curli, irreversibly formed fibers with bacterial DNA during biofilm formation. This interaction accelerated amyloid polymerization and created potent immunogenic complexes that activated immune cells, including dendritic cells, to produce cytokines such as type I interferons, which are pathogenic in systemic lupus erythematosus (SLE). When given systemically, curli-DNA composites triggered immune activation and production of autoantibodies in lupus-prone and wild-type mice. We also found that the infection of lupus-prone mice with curli-producing bacteria triggered higher autoantibody titers compared to curli-deficient bacteria. These data provide a mechanism by which the microbiome and biofilm-producing enteric infections may contribute to the progression of SLE and point to a potential molecular target for treatment of autoimmunity.
•Bacterial amyloid curli and DNA composites form within bacterial biofilms•DNA accelerates the polymerization of bacterial amyloid curli•Curli-DNA composites induce autoantibodies and type I interferon•Infections with amyloid-expressing bacteria trigger autoimmunity
Biofilms, multicellular bacterial communities, are associated with numerous infections including UTIs, rhinosinusitis, and periodontal disease. Tükel and colleagues show that bacterial amyloids and eDNA, components of biofilms, form immunogenic complexes that accelerate the progression of an autoimmune disease, SLE, via the generation of autoantibodies and type I interferon response.
Milk produced in udder cells is sterile but due to its high nutrient content, it can be a good growth substrate for contaminating bacteria. The quality of milk is monitored via somatic cell counts ...and total bacterial counts, with prescribed regulatory limits to ensure quality and safety. Bacterial contaminants can cause disease, or spoilage of milk and its secondary products. Aerobic spore-forming bacteria, such as those from the genera Sporosarcina, Paenisporosarcina, Brevibacillus, Paenibacillus, Geobacillus and Bacillus, are a particular concern in this regard as they are able to survive industrial pasteurization and form biofilms within pipes and stainless steel equipment. These single or multiple-species biofilms become a reservoir of spoilage microorganisms and a cycle of contamination can be initiated. Indeed, previous studies have highlighted that these microorganisms are highly prevalent in dead ends, corners, cracks, crevices, gaskets, valves and the joints of stainless steel equipment used in the dairy manufacturing plants. Hence, adequate monitoring and control measures are essential to prevent spoilage and ensure consumer safety. Common controlling approaches include specific cleaning-in-place processes, chemical and biological biocides and other novel methods. In this review, we highlight the problems caused by these microorganisms, and discuss issues relating to their prevalence, monitoring thereof and control with respect to the dairy industry.
At the turn of the millennium, a review paper was published in this journal on talent identification and development in soccer (Williams & Reilly, 2000). In the current paper, we assess progress made ...in this field over the last twenty years relative to the areas for future research highlighted in the original review. We evaluate developments in light of the calls made by Williams and Reilly to: a) undertake more multidisciplinary rather than mono-disciplinary research; b) embrace longitudinal rather than cross-sectional research designs; c) expand the research base on female football; and, d) better identify the subjective criteria used by scouts when selecting one player over another for entry into a formalised training environment. The body of mono-disciplinary research on this topic continues to expand, and progress has been made in publishing multidisciplinary, prospective, longitudinal data sets, along with advanced statistical modelling procedures, as well as in identifying the experiential criteria used by scouts. We found some variables in these studies have predictive value from adolescence to adult performance level in soccer. We present suggestions for future research to enhance knowledge and understanding of the best practices underpinning the identification and development of future generations of professional players.
The diagnosis of autism spectrum disorder (ASD) at the earliest age possible is important for initiating optimally effective intervention. In the United States the average age of diagnosis is 4 ...years. Identifying metabolic biomarker signatures of ASD from blood samples offers an opportunity for development of diagnostic tests for detection of ASD at an early age.
To discover metabolic features present in plasma samples that can discriminate children with ASD from typically developing (TD) children. The ultimate goal is to identify and develop blood-based ASD biomarkers that can be validated in larger clinical trials and deployed to guide individualized therapy and treatment.
Blood plasma was obtained from children aged 4 to 6, 52 with ASD and 30 age-matched TD children. Samples were analyzed using 5 mass spectrometry-based methods designed to orthogonally measure a broad range of metabolites. Univariate, multivariate and machine learning methods were used to develop models to rank the importance of features that could distinguish ASD from TD.
A set of 179 statistically significant features resulting from univariate analysis were used for multivariate modeling. Subsets of these features properly classified the ASD and TD samples in the 61-sample training set with average accuracies of 84% and 86%, and with a maximum accuracy of 81% in an independent 21-sample validation set.
This analysis of blood plasma metabolites resulted in the discovery of biomarkers that may be valuable in the diagnosis of young children with ASD. The results will form the basis for additional discovery and validation research for 1) determining biomarkers to develop diagnostic tests to detect ASD earlier and improve patient outcomes, 2) gaining new insight into the biochemical mechanisms of various subtypes of ASD 3) identifying biomolecular targets for new modes of therapy, and 4) providing the basis for individualized treatment recommendations.
Mechanistic home range analysis Moorcroft, Paul; Lewis, Mark A
2006, 2006., 20131031, 2013, 2006-01-01, Letnik:
43
eBook, Book
Spatial patterns of movement are fundamental to the ecology of animal populations, influencing their social organization, mating systems, demography, and the spatial distribution of prey and ...competitors. However, our ability to understand the causes and consequences of animal home range patterns has been limited by the descriptive nature of the statistical models used to analyze them. InMechanistic Home Range Analysis, Paul Moorcroft and Mark Lewis develop a radically new framework for studying animal home range patterns based on the analysis of correlated random work models for individual movement behavior. They use this framework to develop a series of mechanistic home range models for carnivore populations.
The authors' analysis illustrates how, in contrast to traditional statistical home range models that merely describe pattern, mechanistic home range models can be used to discover the underlying ecological determinants of home range patterns observed in populations, make accurate predictions about how spatial distributions of home ranges will change following environmental or demographic disturbance, and analyze the functional significance of the movement strategies of individuals that give rise to observed patterns of space use.
By providing researchers and graduate students of ecology and wildlife biology with a more illuminating way to analyze animal movement,Mechanistic Home Range Analysiswill be an indispensable reference for years to come.
Plant pathogens and parasites are a major threat to global food security. Plant parasitism has arisen four times independently within the phylum Nematoda, resulting in at least one parasite of every ...major food crop in the world. Some species within the most economically important order (Tylenchida) secrete proteins termed effectors into their host during infection to re-programme host development and immunity. The precise detail of how nematodes evolve new effectors is not clear. Here we reconstruct the evolutionary history of a novel effector gene family. We show that during the evolution of plant parasitism in the Tylenchida, the housekeeping glutathione synthetase (GS) gene was extensively replicated. New GS paralogues acquired multiple dorsal gland promoter elements, altered spatial expression to the secretory dorsal gland, altered temporal expression to primarily parasitic stages, and gained a signal peptide for secretion. The gene products are delivered into the host plant cell during infection, giving rise to "GS-like effectors". Remarkably, by solving the structure of GS-like effectors we show that during this process they have also diversified in biochemical activity, and likely represent the founding members of a novel class of GS-like enzyme. Our results demonstrate the re-purposing of an endogenous housekeeping gene to form a family of effectors with modified functions. We anticipate that our discovery will be a blueprint to understand the evolution of other plant-parasitic nematode effectors, and the foundation to uncover a novel enzymatic function.
Pleiotropy is defined as the phenomenon of a single gene locus influencing two or more distinct phenotypic traits. However, nicotinamide adenine dinucleotide (NAD+) deficiency through diet alone can ...cause multiple or single malformations in mice. Additionally, humans with decreased NAD+ production due to changes in pathway genes display similar malformations. Here, I hypothesize NAD+ deficiency as a pleiotropic mechanism for multiple malformation conditions, including limb‐body wall complex (LBWC), pentalogy of Cantrell (POC), omphalocele‐exstrophy‐imperforate anus‐spinal defects (OEIS) complex, vertebral‐anal‐cardiac‐tracheoesophageal fistula‐renal‐limb (VACTERL) association (hereafter VACTERL), oculoauriculovertebral spectrum (OAVS), Mullerian duct aplasia‐renal anomalies‐cervicothoracic somite dysplasia (MURCS), sirenomelia, and urorectal septum malformation (URSM) sequence, along with miscarriages and other forms of congenital malformation. The term Congenital NAD Deficiency Disorder (CNDD) could be considered for patients with these malformations; however, it is important to emphasize there have been no confirmatory experimental studies in humans to prove this hypothesis. In addition, these multiple malformation conditions should not be considered individual entities for the following reasons: First, there is no uniform consensus of clinical diagnostic criteria and all of them fail to capture cases with partial expression of the phenotype. Second, reports of individuals consistently show overlapping features with other reported conditions in this group. Finally, what is currently defined as VACTERL is what I would refer to as a default label when more striking features such as body wall defects, caudal dysgenesis, or cloacal exstrophy are not present.
Bolide impact and flood volcanism compete as leading candidates for the cause of terminal-Cretaceous mass extinctions. High-precision 40Ar/39Ar data indicate that these two mechanisms may be ...genetically related, and neither can be considered in isolation. The existing Deccan Traps magmatic system underwent a state shift approximately coincident with the Chicxulub impact and the terminal-Cretaceous mass extinctions, after which ∼70% of the Traps' total volume was extruded in more massive and more episodic eruptions. Initiation of this new regime occurred within ∼50,000 years of the impact, which is consistent with transient effects of impact-induced seismic energy. Postextinction recovery of marine ecosystems was probably suppressed until after the accelerated volcanism waned.
Fast negative breakdown in thunderstorms Tilles, Julia N; Liu, Ningyu; Stanley, Mark A ...
Nature communications,
04/2019, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Thunderstorms are natural laboratories for studying electrical discharges in air, where the vast temporal, spatial, and energy scales available can spawn surprising phenomena that reveal deficiencies ...in our understanding of dielectric breakdown. Recent discoveries, such as sprites, jets, terrestrial gamma ray flashes, and fast positive breakdown, highlight the diversity of complex phenomena that thunderstorms can produce, and point to the possibility for electrical breakdown/discharge mechanisms beyond dielectric breakdown theory based mainly on laboratory experiments. Here we present one such confounding discovery, termed fast negative breakdown, that does not fit with our current understanding of dielectric breakdown. Our adaptation of radio astronomy imaging techniques to study extremely transient lightning-associated events confirms that electrical breakdown in thunderstorms can begin with oppositely-directed fast breakdown of negative polarity, similar and in addition to fast positive breakdown expected from conventional dielectric theory and recent observations. The discovery of fast negative breakdown calls for an addendum to the physical description of electrical discharges in air.
A long-standing but fundamental question in lightning studies concerns how lightning is initiated inside storms, given the absence of physical conductors. The issue has revolved around the question ...of whether the discharges are initiated solely by conventional dielectric breakdown or involve relativistic runaway electron processes. Here we report observations of a relatively unknown type of discharge, called fast positive breakdown, that is the cause of high-power discharges known as narrow bipolar events. The breakdown is found to have a wide range of strengths and is the initiating event of numerous lightning discharges. It appears to be purely dielectric in nature and to consist of a system of positive streamers in a locally intense electric field region. It initiates negative breakdown at the starting location of the streamers, which leads to the ensuing flash. The observations show that many or possibly all lightning flashes are initiated by fast positive breakdown.
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