A Dangerous Mix: From Natural Variation to Genetic Incompatibilities in Arabidopsis thaliana and Arabidopsis arenosa

Plants and pathogens have co-evolved for millennia. As part of this long-term interaction, both the preservation of long-standing genetic variation, as well as the generation of novel genetic material is required from both the plant and the pathogen side to remain competitive when facing each other. As a consequence, some members of the plant immune system are highly diversified. Such is the case for plant NLRs, which act as intracellular receptors that recognize incoming pathogen effectors, thereby initiating a signalling cascade and ultimately resulting in cell death. The extensive variability of NLRs enables the recognition of a wide spectrum of pathogen effectors. However, sometimes this variability can backfire: When two divergent elements of the plant immune system, often two NLRs, or one NLR and another immune system component, meet in a hybrid plant – the progeny of a cross between two different accessions – they can trigger an immune response in the absence of a pathogen. This phenomenon is called hybrid incompatibility. Here, I study two sets of hybrid incompatibility cases in Arabidopsis thaliana and a case of inbreeding depression in its outcrossing relative Arabidopsis arenosa. In the first project, I study a set of A. thaliana incompatibility cases which are are the result of incompatible interactions between the NLR cluster RPP7, which confers strain-specific resistance to downy mildew, and RPW8, an atypical non-NLR resistance (R) gene cluster that confers broad-spectrum resistance to filamentous pathogens. I describe three independent cases where allele-specific interactions between these two loci result in incompatible hybrids. In addition, for two of these cases, I identify the causal genes for incompatibility from the RPW8 side: RPW8.1 and HR4. The resulting proteins of these two causal genes for incompatibility show length polymorphisms across different accessions which are characterized by 21- or 14- amino acid repeat number variations in their C terminal. I show that these C terminal repeats largely modulate the severity of the hybrid phenotype, and that only accessions carrying long RPW8.1 and short HR4 protein variants are incompatible when combined with particular RPP7 proteins. In the second project, I study a set of A. thaliana hybrid incompatibility cases where the hybrid is severely necrotic, does not develop past the cotyledon stage, and dies early on. I show that massive transcriptional changes take place in the hybrid, including the upregulation of most NLR genes, which likely contribute to its severely necrotic phenotype. I then identify the causal loci for incompatibility, DM10 and DM11, and show that DM10 is a singleton NLR that was relocated from an NLR gene cluster after A. thaliana speciation. I establish that the risk DM10 allele carries a premature stop codon, and although common and geographically widespread in the global A. thaliana population, co-occurrence with the risk DM11 allele is absent. In the third project, I screened for the presence of potential hybrid incompatibility cases occurring in natural A. arenosa populations, and show that heritable deleterious phenotypes are common, but, at least in some cases, likely the result of inbreeding depression. In short, my work presents a roadmap starting from identifying potential hybrid incompatibility cases to mapping and experimentally confirming the underlying causal loci, to establishing the underlying genetic and evolutionary processes building up to these incompatibilities

Habitability: CAMELOT 4

During 1988 to 1989 the NASA/USRA Advanced Design Program sponsored research and design efforts aimed at developing habitability criteria and at defining a habitability concept as a useful tool in understanding and evaluating dwellings for prolonged stays in extraterrestrial space. The Circulating Auto sufficient Mars-Earth Luxurious Orbital Transport (CAMELOT) was studied as a case in which the students would try to enhance the quality of life of the inhabitants by applying architectural design methodology. The study proposed 14 habitability criteria considered necessary to fulfill the defined habitability concept, which is that state of equilibrium that results from the interaction between components of the Individual Architecture Mission Complex, which allows a person to sustain physiological homeostatis, adequate performance, and acceptable social relationships. Architecture, design development, refinements and revisions to improve the quality of life, new insights on artificial gravity, form and constitution problems, and the final design concept are covered

Analysis of acoustic noise spectrum of domestic induction heating systems controlled by phase-accumulator modulators

In domestic induction heating (IH) applications, the modulation technique applied to the inverter has a high influence on the acoustic noise emissions. These noise emissions must be avoided since they may be audible and annoying to the final user. This paper analyzes the acoustic noise emissions that appear when a series half-bridge resonant inverter is operated with a phase-accumulator based modulator. This modulation technique has the advantage of operating in the frequency domain, and it is compared with the classical PWM modulator regarding the audible noise generated. The frequencies of the tones in the acoustic noise spectrum are theoretically calculated from the parameters of the phaseaccumulator based modulator. The SFM (Spectral Flatness Measure) is used to quantify the number of cases in which tones are generated by the modulation. Two techniques are applied to the phase-accumulator based modulator and their effect is tested. Theoretical results are experimentally verified

Whole genome analysis of p38 SAPK-mediated gene expression upon stress

<p>Abstract</p> <p>Background</p> <p>Cells have the ability to respond and adapt to environmental changes through activation of stress-activated protein kinases (SAPKs). Although p38 SAPK signalling is known to participate in the regulation of gene expression little is known on the molecular mechanisms used by this SAPK to regulate stress-responsive genes and the overall set of genes regulated by p38 in response to different stimuli.</p> <p>Results</p> <p>Here, we report a whole genome expression analyses on mouse embryonic fibroblasts (MEFs) treated with three different p38 SAPK activating-stimuli, namely osmostress, the cytokine TNFα and the protein synthesis inhibitor anisomycin. We have found that the activation kinetics of p38α SAPK in response to these insults is different and also leads to a complex gene pattern response specific for a given stress with a restricted set of overlapping genes. In addition, we have analysed the contribution of p38α the major p38 family member present in MEFs, to the overall stress-induced transcriptional response by using both a chemical inhibitor (SB203580) and p38α deficient (p38α^-/-) MEFs. We show here that p38 SAPK dependency ranged between 60% and 88% depending on the treatments and that there is a very good overlap between the inhibitor treatment and the ko cells. Furthermore, we have found that the dependency of SAPK varies depending on the time the cells are subjected to osmostress.</p> <p>Conclusions</p> <p>Our genome-wide transcriptional analyses shows a selective response to specific stimuli and a restricted common response of up to 20% of the stress up-regulated early genes that involves an important set of transcription factors, which might be critical for either cell adaptation or preparation for continuous extra-cellular changes. Interestingly, up to 85% of the up-regulated genes are under the transcriptional control of p38 SAPK. Thus, activation of p38 SAPK is critical to elicit the early gene expression program required for cell adaptation to stress.</p

Auxiliary System for Chemical and Production Data Analysis: ANAGEOT

This paper describes a computational tool developed to aid the analysis of chemical, isotopic and production data of geothermal wells. ANAGEOT is an interactive and user-friendly software that allows quickly and efficient manner, modification, retrieval and visualization of the wide amounts of data involved in the study of reservoirs. ANAGEOT optimizes time and resources, due to high quantity of historical data of most of the wells of various petroleum and geothermal fields which involve information sometimes of very long time periods. The system has the flexibility to work with different fields, considering a database for each one A very important feature of this tool is that the reports, charts and graphs are generated in a way which can be edited at any time. Similarly these can be used as source files for other applications, because they are generated in wide commercial use applications such as Microsoft Word, Excel and Golden Grapher

Infected Dendritic Cells Facilitate Systemic Dissemination and Transplacental Passage of the Obligate Intracellular Parasite Neospora caninum in Mice

The obligate intracellular parasite Neospora caninum disseminates across the placenta and the blood-brain barrier, to reach sites where it causes severe pathology or establishes chronic persistent infections. The mechanisms used by N. caninum to breach restrictive biological barriers remain elusive. To examine the cellular basis of these processes, migration of different N. caninum isolates (Nc-1, Nc-Liverpool, Nc-SweB1 and the Spanish isolates: Nc-Spain 3H, Nc-Spain 4H, Nc-Spain 6, Nc-Spain 7 and Nc-Spain 9) was studied in an in vitro model based on a placental trophoblast-derived BeWo cell line. Here, we describe that infection of dendritic cells (DC) by N. caninum tachyzoites potentiated translocation of parasites across polarized cellular monolayers. In addition, powered by the parasite's own gliding motility, extracellular N. caninum tachyzoites were able to transmigrate across cellular monolayers. Altogether, the presented data provides evidence of two putative complementary pathways utilized by N. caninum, in an isolate-specific fashion, for passage of restrictive cellular barriers. Interestingly, adoptive transfer of tachyzoite-infected DC in mice resulted in increased parasitic loads in various organs, e.g. the central nervous system, compared to infections with free parasites. Inoculation of pregnant mice with infected DC resulted in an accentuated vertical transmission to the offspring with increased parasitic loads and neonatal mortality. These findings reveal that N. caninum exploits the natural cell trafficking pathways in the host to cross cellular barriers and disseminate to deep tissues. The findings are indicative of conserved dissemination strategies among coccidian apicomplexan parasites

Influence of Neospora caninum intra-specific variability in the outcome of infection in a pregnant BALB/c mouse model

Previous assays in pregnant animals have demonstrated the effect of different host factors and timing of infection on the outcome of neosporosis during pregnancy. However, the influence of Neospora caninum isolate itself has been poorly investigated. Here, we compared the effects on clinical outcome and vertical transmission observed in a pregnant mouse model following infection with 10 different N. caninum isolates. The isolates in our study included the Nc-Liv isolate and nine N. caninum isolates obtained from calves. Female BALB/c mice were inoculated with 2 × 106 tachyzoites at day 7 of pregnancy. Morbidity and mortality, in both dams and offspring during the course of infection, and transmission to progeny at day 30 postpartum were evaluated. The serum IgG1 and IgG2a production in dams were also examined. All dams showed elevated IgG1 and IgG2a responses, confirming N. caninum infection, although signs of disease were only exhibited in dams infected with 4 of the 10 isolates (Nc-Spain 4H, Nc-Spain 5H, Nc-Spain 7 and Nc-Liv). In neonates, clinical signs were observed in all N. caninum-infected groups, and neonatal mortality rates varied from greater than 95% with the isolates mentioned above to less than 32.5% with the other isolates. Vertical transmission rates, as assessed by parasite PCR-detection in neonate brains, also varied from 50% to 100% according to the isolate implicated. These results confirm the wide pathogenic and transmission variability of N. caninum. The intra-specific variability observed herein could help us explain the differences in the outcome of the infection in the natural host

Impact of the Pandemic on NonInfected Cardiometabolic Patients: A Survey in Countries of Latin America—Rationale and Design of the CorCOVID LATAM Study

Background: The first case of coronavirus 2019 (COVID-19) in Latin America was detected on February 26th, 2020, in Brazil. Later, in June, the World Health Organization announced that the focus of the outbreak had shifted to Latin America, where countries already had poor control of indicators of noncommunicable diseases (NCDs). Concerns about coronavirus infection led to a reduced number of visits and hospitalizations in patients with NCDs, such as cardiovascular disease, diabetes, and cancer. There is a need to determine the impact of the COVID-19 pandemic on patients who have cardiometabolic diseases but do not have clinical evidence of COVID-19 infection. Methods: The CorCOVID LATAM is a cross-sectional survey of ambulatory cardiometabolic patients with no history or evidence of COVID-19 infection. The study will be conducted by the Interamerican Society of Cardiology. An online survey composed of 38 questions using Google Forms will be distributed to patients of 13 Latin American Spanish-speaking countries from June 15th to July 15th, 2020. Data will be analyzed by country and regions. Seven clusters of questions will be analyzed: demographics, socioeconomic and educational level, cardiometabolic profile, lifestyle and habits, body-weight perception, medical follow-up and treatments, and psychological symptoms. Results: Final results will be available upon completion of the study. Conclusions: The present study will provide answers regarding the impact of the COVID-19 pandemic on noninfected cardiometabolic patients. Data on this topic are scarce, as it is an unprecedented threat, without short-term solutions.Fil: Lopez Santi, Ricardo. Hospital Italiano de La Plata; ArgentinaFil: Piskorz, Daniel Leonardo. No especifíca;Fil: Marquez, Manlio F.. Instituto Nacional de Cardiologia Ignacio Chavez; MéxicoFil: Ramirez Ramos, Cristhian. Centro de Medicina del Ejercicio y Rehabilitación Cardíaca; ColombiaFil: Renna, Nicolas Federico. Hospital Espanol de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Ibarrola, Martin. No especifíca;Fil: Wyss, Fernando Stuardo. Servicios y Tecnología Cardiovascular de Guatemala; GuatemalaFil: Naranjo Dominguez, Adrián. Instituto de Cardiologia y Cirugia Cardiovascular; CubaFil: Perez, Gonzalo Emanuel. No especifíca;Fil: Farina, Juan María. No especifíca;Fil: Forte, Ezequiel. Centro Diagnóstico Cardiovascular; ArgentinaFil: Juarez Lloclla, Jorge Paul. Hospital de Apoyo II Santa Rosa; PerúFil: Flores de Espinal, Emma. Hospital Nacional San Juan De Dios; El SalvadorFil: Puente Barragan, Adriana. Instituto Mexicano del Seguro Social; MéxicoFil: Ruise, Mauro Gabriel. Clínica Yunes; ArgentinaFil: Delgado, Diego. University of Toronto; CanadáFil: Baranchuk, Adrian. Queens University; Canad

cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE) that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites

A novel deep targeted sequencing method for minimal residual disease monitoring in acute myeloid leukemia

A high proportion of patients with acute myeloid leukemia who achieve minimal residual disease negative status ultimately relapse because a fraction of pathological clones remains undetected by standard methods. We designed and validated a high-throughput sequencing method for minimal residual disease assessment of cell clonotypes with mutations of NPM1, IDH1/2 and/or FLT3-single nucleotide variants. For clinical validation, 106 follow-up samples from 63 patients in complete remission were studied by sequencing, evaluating the level of mutations detected at diagnosis. The predictive value of minimal residual disease status by sequencing, multiparameter flow cytometry, or quantitative polymerase chain reaction analysis was determined by survival analysis. The sequencing method achieved a sensitivity of 10-4 for single nucleotide variants and 10-5 for insertions/deletions and could be used in acute myeloid leukemia patients who carry any mutation (86% in our diagnostic data set). Sequencing-determined minimal residual disease positive status was associated with lower disease-free survival (hazard ratio 3.4, P=0.005) and lower overall survival (hazard ratio 4.2, P<0.001). Multivariate analysis showed that minimal residual disease positive status determined by sequencing was an independent factor associated with risk of death (hazard ratio 4.54, P=0.005) and the only independent factor conferring risk of relapse (hazard ratio 3.76, P=0.012). This sequencing-based method simplifies and standardizes minimal residual disease evaluation, with high applicability in acute myeloid leukemia. It is also an improvement upon flow cytometry- and quantitative polymerase chain reaction-based prediction of outcomes of patients with acute myeloid leukemia and could be incorporated in clinical settings and clinical trials.This study was supported by the Subdirección General de Investigación Sanitaria (Instituto de Salud Carlos III, Spain) grants PI13/02387 and PI16/01530, and the CRIS against Cancer foundation grant 2014/0120. ML holds a postdoctoral fellowship of the Spanish Ministry of Economy and Competitiveness (FPDI-2013- 16409). PRP holds a postdoctoral fellowship of the Spanish Instituto de Salud Carlos III: Contrato Predoctoral de Formación en Investigación en Salud i-PFIS (IFI 14/00008).S