207 research outputs found
Characterization of the pheromone communication channel in Mamestra configurata, the bertha armyworm
The bertha armyworm (BAW), Mamestra configurata, is one of the major insect pests feeding on a wide range of plant species, including canola, across western Canada. The components of the sex pheromone blend specific to M. configurata were identified in the 1970’s and are currently used in the pheromone trap monitoring system. However, there is evidence that geographic BAW populations develop at different rates and respond differently to the commercially prepared pheromone lures which affects our ability to accurately predict economic infestation levels for this pest. Collection of egg masses and pupae from several western Canada locations during the last BAW outbreak (2011-2014) presented a rare opportunity to investigate the genetics and biology of pheromone communication in M. configurata in field populations as compared to the long-term laboratory reared strain. My research encompassed aspects of both female pheromone production and male response to the female produced signal. I utilized next generation sequencing combined with bioinformatic analysis to identify and characterize genes involved in pheromone biosynthesis in females and chemosensory proteins involved in pheromone reception in males and females. I also used a novel single nucleotide polymorphism identification strategy to characterize genetic variation within pheromone specific chemosensory gene sequences among males from three BAW populations. The female pheromone gland analysis via gas chromatography coupled mass spectroscopy indicated that although, the amount of major and minor pheromone components varied greatly between individuals within a population, the pheromone blend ratios were not found to be significantly different between the two subpopulations investigated. Behavioural assays in the wind tunnel showed a marked difference in the ability of colony reared BAW males to take flight and reach the pheromone source as compared to field population males. Electrophysiological recordings obtained from colony and field population BAW male antenna showed significant loss of sensitivity to the minor pheromone component in the colony reared males. The knowledge gained from these studies will serve as a foundation for future research aimed at developing more effective integrated pest management strategies utilizing the pheromone communication channel for M. configurata
DIVERSIFICATION AND REAL EXCHANGE RATE HEDGING IN EQUITY HOLDINGS
The purpose of this paper is to examine the allocation of cross-border equity holdings and provide evidence that investors use equities to hedge real exchange fluctuations. The famous Backus-Smith (1993) condition, that relates the real exchange rates and relative consumption, is utilized in a two-country endowment economy introduced by Coeurdacier and Gourinchas (2009), in this case however, only stocks are traded. An important relationship between the real exchange rates, relative returns and equity positions is uncovered and subsequently incorporated into a gravity model developed by Coeurdacier and Guibaud (2011). Based on the uncovered relationship a new explanatory variable representing the correlation between the changes in real exchange rates and excess returns is utilized as a measure of the variation in bilateral equity holdings. If negative correlations imply home bias and positive correlations foreign bias, then given the particular market characteristics, the model measures whether investors hold equities to hedge the fluctuations in real exchange rate returns to smooth consumption. Although the primary results confirm the proposition, the findings vary with respect to the specifications included, and more empirical testing should be conducted
Lack of association between serotonin transporter gene polymorphism 5-HTTLPR and smoking among Polish population: a case-control study
<p>Abstract</p> <p>Background</p> <p>A better understanding of the genetic determinants of tobacco smoking might help in developing more effective cessation therapies, tailored to smokers' genotype. Insertion/deletion polymorphism in the promoter region of the serotonin transporter gene (<it>5-HTTLPR</it>) has been linked to vulnerability to smoking and ability to quit. We aimed to determine whether <it>5-HTTLPR </it>genotype is associated with smoking behavior in Caucasians from Northern Poland and to investigate other risk factors for tobacco smoking.</p> <p>Methods</p> <p><it>5-HTTLPR </it>genotypes were determined in 149 ever smokers (66 females; mean age 53.0 years) and 158 gender and ethnicity matched never smoking controls (79 females; mean age 45.0 years) to evaluate the association of this polymorphism with ever smoking status. Analysis of smokers was performed to evaluate the role of <it>5-HTTLPR </it>in the age of starting regular smoking, the number of cigarettes smoked daily, pack-years, FTND score, duration of smoking, and the mean length of the longest abstinence on quitting. Genotype was classified according to the presence or absence of the short (<it>S</it>) allele vs. the long (<it>L</it>) allele of <it>5-HTTLPR </it>(i.e., <it>S/S </it>+ <it>S/L </it>vs. <it>L/L</it>). Logistic regression analysis was also used to evaluate correlation between ever smoking and several selected variables.</p> <p>Results</p> <p>We found no significant differences in the rates of <it>S </it>allele carriers in ever smokers and never smokers, and no relationship was observed between any quantitative measures of smoking and the polymorphism. Multivariate analysis demonstrated significant association between the older age (OR = 4.03; 95% CI: 2.33–6.99) and alcohol dependence (OR = 10.23; 95% CI: 2.09–50.18) and smoking.</p> <p>Conclusion</p> <p><it>5-HTTLPR </it>seems to be not a major factor determining cigarette smoking in Poles. Probably, the risk of smoking results from a large number of genes, each contributing a small part of the overall risk, while numerous non-genetic factors might strongly influence these genetic undergrounds of susceptibility to smoking.</p
Fatal course of Churg-Strauss disease
Churg-Strauss syndrome (CSS) is an allergic vasculitis, which is commonly characterized by asthma and
allergic rhinitis, eosinophila and eosinophillic infiltration of organs. Approximately 60-90% of patients with
CSS are long-term survivors. We presented the case of fatal case of the disease complicated by pulmonary
embolism, arrhythmia, and eventually - cerebral bleeding.Churg-Strauss syndrome (CSS) is an allergic vasculitis, which is commonly characterized by asthma and
allergic rhinitis, eosinophila and eosinophillic infiltration of organs. Approximately 60-90% of patients with
CSS are long-term survivors. We presented the case of fatal case of the disease complicated by pulmonary
embolism, arrhythmia, and eventually - cerebral bleeding
Design of deep excavations according to Eurocode 7
The paper presents the procedure of introducing Eurocode 7 into the design practice in Poland. Within the paper, currently used design methods have been compared to new ones, which will be soon used together with the introduction of Eurocodes. In order to make the comparison, numerical analysis has been performed on two simple example cases presented by the committee ERTC-10 „Evaluation of Eurocode 7”. That gave authors an opportunity to assess and compare properly different design approaches – up-to-date and new, now being introduced. Final conclusions and issues open for further discussion have been presented in the end of the paper
Emergence and potential transmission route of avian influenza A (H5N1) virus in domestic cats in Poland, June 2023
In June 2023, a fatal disease outbreak in cats occurred in Poland. Most cases tested in Poland (29 of 47) were positive for highly pathogenic avian influenza (HPAI) A (H5N1) virus. Genetic analyses revealed clade 2.3.4.4b with point mutations indicative of initial mammalian hosts adaptations. Cat viral sequences were highly similar (n = 21), suggesting a potential common infection source. To investigate possible infection routes, our group tested food samples from affected households. HPAI H5N1 virus was detected in one poultry meat sample.</p
Bacteroides fragilis expresses three proteins similar to Porphyromonas gingivalis HmuY: Hemophore-like proteins differentially evolved to participate in heme acquisition in oral and gut microbiomes
Oral and gut microbiomes are important for the maintenance of homeostasis in the human body. Altered or disturbed mutualism between their members results in dysbiosis with local injury and subsequent systemic diseases. The high bacterial density causes intense competition among microbiome residents to acquire nutrients, including iron and heme, the latter of high importance for heme auxotrophic members of the Bacteroidetes phylum. Our main hypothesis is that the heme acquisition mechanism, with the leading role played by a novel HmuY family of hemophore-like proteins, can be used to fulfill nutritional requirements and increase virulence. We characterized HmuY homologs expressed by Bacteroides fragilis and compared their properties with the first representative of this family, the HmuY protein of Porphyromonas gingivalis. In contrast to other Bacteroidetes members, B. fragilis produces three HmuY homologs (Bfr proteins). All bfr transcripts were produced at higher levels in bacteria starved of iron and heme (fold change increase ~60, ~90, and ~70 for bfrA, bfrB, and bfrC, respectively). X-ray protein crystallography showed that B. fragilis Bfr proteins are structurally similar to P. gingivalis HmuY and to other homologs, except for differences in the potential heme-binding pockets. BfrA binds heme, mesoheme, and deuteroheme, but preferentially under reducing conditions, using Met175 and Met146 to coordinate heme iron. BfrB binds iron-free protoporphyrin IX and coproporphyrin III, whereas BfrC does not bind porphyrins. HmuY is capable of heme sequestration from BfrA, which might increase the ability of P. gingivalis to cause dysbiosis also in the gut microbiome
Serum metabolomics identified specific lipid compounds which may serve as markers of disease progression in patients with Alström and Bardet-Biedl syndromes
Objectives: Alström syndrome (ALMS) and Bardet-Biedl syndrome (BBS) are among the so-called ciliopathies and are associated with the development of multiple systemic abnormalities, including early childhood obesity and progressive neurodegeneration. Given the progressive deterioration of patients’ quality of life, in the absence of defined causal treatment, it seems reasonable to identify the metabolic background of these diseases and search for their progression markers. The aim of this study was to find metabolites characteristic to ALMS and BBS, correlating with clinical course parameters, and related to the diseases progression.Methods: Untargeted metabolomics of serum samples obtained from ALMS and BBS patients (study group; n = 21) and obese/healthy participants (control group; each of 35 participants; n = 70) was performed using LC-QTOF-MS method at the study onset and after 4 years of follow-up.Results: Significant differences in such metabolites as valine, acylcarnitines, sphingomyelins, phosphatidylethanolamines, phosphatidylcholines, as well as lysophosphatidylethanolamines and lysophosphatidylcholines were observed when the study group was compared to both control groups. After a follow-up of the study group, mainly changes in the levels of lysophospholipids and phospholipids (including oxidized phospholipids) were noted. In addition, in case of ALMS/BBS patients, correlations were observed between selected phospholipids and glucose metabolism parameters. We also found correlations of several LPEs with patients’ age (p < 0.05), but the level of only one of them (hexacosanoic acid) correlated negatively with age in the ALMS/BBS group, but positively in the other groups.Conclusion: Patients with ALMS/BBS have altered lipid metabolism compared to controls or obese subjects. As the disease progresses, they show elevated levels of lipid oxidation products, which may suggest increased oxidative stress. Selected lipid metabolites may be considered as potential markers of progression of ALMS and BBS syndromes
Glycation of Host Proteins Increases Pathogenic Potential of Porphyromonas gingivalis
The non-enzymatic addition of glucose (glycation) to circulatory and tissue proteins is a ubiquitous pathophysiological consequence of hyperglycemia in diabetes. Given the high incidence of periodontitis and diabetes and the emerging link between these conditions, it is of crucial importance to define the basic virulence mechanisms employed by periodontopathogens such as Porphyromonas gingivalis in mediating the disease process. The aim of this study was to determine whether glycated proteins are more easily utilized by P. gingivalis to stimulate growth and promote the pathogenic potential of this bacterium. We analyzed the properties of three commonly encountered proteins in the periodontal environment that are known to become glycated and that may serve as either protein substrates or easily accessible heme sources. In vitro glycated proteins were characterized using colorimetric assays, mass spectrometry, far- and near-UV circular dichroism and UV–visible spectroscopic analyses and SDS-PAGE. The interaction of glycated hemoglobin, serum albumin and type one collagen with P. gingivalis cells or HmuY protein was examined using spectroscopic methods, SDS-PAGE and co-culturing P. gingivalis with human keratinocytes. We found that glycation increases the ability of P. gingivalis to acquire heme from hemoglobin, mostly due to heme sequestration by the HmuY hemophore-like protein. We also found an increase in biofilm formation on glycated collagen-coated abiotic surfaces. We conclude that glycation might promote the virulence of P. gingivalis by making heme more available from hemoglobin and facilitating bacterial biofilm formation, thus increasing P. gingivalis pathogenic potential in vivo
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