EFFICIENT SCREENING PROCEDURE FOR BLACK SIGATOKA DISEASE OF BANANA

Current methods for screening for reaction of Mycosphaerella fijiensis are mostly field based and subject to variability caused by weather conditions. The objective of this study was to develop an efficient screening procedure for black sigatoka disease in order to provide a reliable controlled environment screening method. A fragmented mycelia-based infection system was developed using weighed mycelia suspensions, in 0.18% water agar. Consistent and repeatable black sigatoka infection was achieved in cv. Gross Michel as a reference susceptible cultivar. The infection system developed was used to validate screenhouse reaction of banana genotypes to M. fijiensis. Three East African highland genotypes (AAA-EA), one plantain genotype (ABB), two dessert (AAB and AAA) and one hybrid genotype (AAAA) were tested. Inoculum of M. fijiensis was adjusted to 15 mg ml-1 fragmented mycelium and applied to the abaxial surfaces of the first two open leaves. Plants were evaluated for 6 weeks post inoculation (PI). Significant differences in the response of the different genotypes, to M. fijiensis infection were observed at 3, 4, 5 and 6 weeks PI. All East African highland and dessert genotypes were susceptible. M9 hybrid and Psang awak (ABB) expressed resistance, characterised by high disease incubation period and slow rate of symptom development, with Psanag awak being the most resistant. Artificial inoculation of in vitro plants with weighed fragmented mycelial suspension, was practicable for determining resistance to M. fijiensis. This is the first report demonstrating that use of weighed fragmented mycelial inoculum spread over the entire leaf surface, can be used to quantitatively assess reaction of banana genotypes to M. fijiensis under screenhouse conditions.Les m\ue9thodes actuelles de d\ue9pistage de Mycosphaerella fijiensis sont essentiellement bas\ue9es sur des \ue9valuations dans le champ et sont souvent sujets \ue0 des variabilit\ue9s climatiques. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9velopper une proc\ue9dure efficace de d\ue9pistage de la maladie foliaire du bananier Sigatoka dans le but de proposer une m\ue9thode de d\ue9pistage non influenc\ue9e par l\u2019environnement. Un syst\ue8me d\u2019infection a \ue9t\ue9 d\ue9velopp\ue9 en se servant de myc\ue9lium en suspension dans 0,18% de solution agar. Des infections consistantes et r\ue9p\ue9t\ue9es ont \ue9t\ue9 r\ue9alis\ue9es in cv. La vari\ue9t\ue9 Gross Michel a \ue9t\ue9 utilis\ue9e comme r\ue9f\ue9rence susceptible. Le syst\ue8me d\u2019infection d\ue9velopp\ue9 a \ue9t\ue9 utilis\ue9 pour valider la r\ue9action des accessions de bananiers en serre \ue0 M. fijiensis. Trois g\ue9notypes de bananiers adapt\ue9s aux hautes altitudes en Afrique de l\u2019Est (AAA-EA), un g\ue9notype de type plantain (ABB), deux d\ue9serts (AAB and AAA) et un hybride (AAAA) ont \ue9t\ue9 test\ue9s. Des inocula de M. fijiensis ont \ue9t\ue9 doses \ue0 15 mg ml-1 et appliqu\ue9s sur la face dorsale des deux premi\ue8res feuilles ouvertes. Les plants ont \ue9t\ue9 \ue9valu\ue9s pendant 6 semaines apr\ue8s inoculation (PI). Des diff\ue9rences significatives ont \ue9t\ue9 observ\ue9es dans les r\ue9ponses des g\ue9notypes \ue0 l\u2019infection \ue0 diff\ue9rents stages apr\ue8s inoculation (3, 4,5 et 6 semaines) de M. fijiensis. Tous les g\ue9notypes de haute altitude et les d\ue9serts ont \ue9t\ue9 r\ue9v\ue9l\ue9s susceptibles. L\u2019hybride M9 et Psang awak (ABB) se sont montr\ue9s r\ue9sistants, ils sont caract\ue9ris\ue9s par une longue p\ue9riode d\u2019incubation et un taux bas de d\ue9veloppement de sympt\uf4mes, Psanag awak s\u2019est r\ue9v\ue9l\ue9 le plus r\ue9sistant. L\u2019inoculation artificielle in vitro des plants avec des suspensions de fragments myc\ue9liens, a \ue9t\ue9 pratique dans la d\ue9termination de la r\ue9sistance \ue0 M. fijiensis. Ceci est le premier r\ue9sultat d\u2019\ue9tude scientifique ayant d\ue9montr\ue9 que cette technique peut \ueatre utilis\ue9e pour l\u2019\ue9valuation de la r\ue9action des g\ue9notypes de bananiers \ue0 l\u2019infection de M. fijiensis dans des conditions d\u2019exp\ue9riences en serre.

Stroke risk estimation across nine European countries in the MORGAM project.

Previous tools for stroke risk assessment have either been developed for specific populations or lack data on non-fatal events or uniform data collection. The purpose of this study was to develop a stepwise model for the estimation of 10 year risk of stroke in nine different countries across Europe.Using data from the MOnica Risk, Genetics, Archiving and Monograph (MORGAM) Project, sex-specific models estimating 10 year risk of stroke were developed using a Cox regression model stratified by country and including modelling of competing risks. Models were developed in a stepwise manner first using only data from questionnaires, and then adding data from physical examinations and finally data from blood samples.During 1,176,296 years of observation, 2928 incident fatal and non-fatal events of stroke were registered. The developed model showed good calibration and accuracy of prediction. The discrimination of the model varied between sex and country but increased with increasing number of variables used (area under the receiver operating characteristic curve between 0.77 and 0.79 in men and between 0.75 and 0.80 in women).The present study shows that using a large multicountry cohort from nine European countries it is possible to develop a stepwise risk estimation model for 10 year risk of stroke tailored to different availability of risk factors and still obtain valid measures of risk even in the simplest form of the model, with increasing performance of the model following increasing complexity. The methods chosen which separate this model from previous models (competing risk and stepwise approach) should be considered for future risk estimation models

Evidence of a causal and modifiable relationship between kidney function and circulating trimethylamine N-oxide

The host-microbiota co-metabolite trimethylamine N-oxide (TMAO) is linked to increased cardiovascular risk but how its circulating levels are regulated remains unclear. We applied "explainable" machine learning, univariate, multivariate and mediation analyses of fasting plasma TMAO concentration and a multitude of phenotypes in 1,741 adult Europeans of the MetaCardis study. Here we show that next to age, kidney function is the primary variable predicting circulating TMAO, with microbiota composition and diet playing minor, albeit significant, roles. Mediation analysis suggests a causal relationship between TMAO and kidney function that we corroborate in preclinical models where TMAO exposure increases kidney scarring. Consistent with our findings, patients receiving glucose-lowering drugs with reno-protective properties have significantly lower circulating TMAO when compared to propensity-score matched control individuals. Our analyses uncover a bidirectional relationship between kidney function and TMAO that can potentially be modified by reno-protective anti-diabetic drugs and suggest a clinically actionable intervention for decreasing TMAO-associated excess cardiovascular risk

Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology

Microbiota-host-diet interactions contribute to the development of metabolic diseases. Imidazole propionate is a novel microbially produced metabolite from histidine, which impairs glucose metabolism. Here, we show that subjects with prediabetes and diabetes in the MetaCardis cohort from three European countries have elevated serum imidazole propionate levels. Furthermore, imidazole propionate levels were increased in subjects with low bacterial gene richness and Bacteroides 2 enterotype, which have previously been associated with obesity. The Bacteroides 2 enterotype was also associated with increased abundance of the genes involved in imidazole propionate biosynthesis from dietary histidine. Since patients and controls did not differ in their histidine dietary intake, the elevated levels of imidazole propionate in type 2 diabetes likely reflects altered microbial metabolism of histidine, rather than histidine intake per se. Thus the microbiota may contribute to type 2 diabetes by generating imidazole propionate that can modulate host inflammation and metabolism

Gauge-origin independent magneto-optical activity within coupled-cluster response theory

We present a gauge-origin independent formulation of the Faraday B term of magnetic circular dichroism and of the Verdet constant of magneto-optical rotation, in terms of first derivatives with respect to the magnetic field strength of gauge invariant coupled cluster response functionals [1]. Gauge invariance is ensured by the derivative formulation in connection with the use of a magnetic field dependent basis of atomic orbitals, the so-called London orbitals. To our knowledge this represent the first application of London atomic orbitals to the calculation of frequency dependent quadratic response properties. The approach can easily be extended to other wavefunction models, and to any other frequency dependent property which can be formulated as total derivative of a (frequency-dependent) functional with respect to the field strengths of a static magnetic perturbation. In other words, any properties for which the frequency dependence is not associated with the magnetic field. This is for example the case for the hypermagnetizabilities in the Cotton-Moutton effect. The implementation of the derived equations is currently undertaken for a CCSD wavefunction on a local version of the Dalton program. [1] S. Coriani, C. H\ue4ttig, P. J\uf8rgensen, T. Helgake

Accurate geometries from ab initio calculations: systems containing second-row atoms and transition metals

The performance of the standard hierarchies of ab initio models HF, MP2, CCSD and CCSD(T) and of correlation consistent basis sets is analyzed in determining bond lengths and bond angles on a set of 32 closed-shell molecules containing second-row elements. The importance of core correlation is assessed using hierarchies of correlation consistent valence and core-valence basis sets, the former used in connection with the frozen-core approximation and the latter freezing only the 1s orbital on the second row atom. Results of the geometry optimization of ferrocene in the eclipsed and staggered conformational forms at the MP2, CCSD and CCSD(T) levels in a TZV2P+f basis set and with 66 valence electrons correlated are also presented

Comparison of standard and damped response formulations of magnetic circular dichroism

We apply damped response theory to the phenomenon of magnetic circular dichroism (MCD), and we investigate how the numerical instability associated with the simulation of the MCD spectrum from individually calculated A and B terms for close lying states can be remedied by the use of damped response theory. We also present a method for calculating the Faraday A term, formulated as a double residue of the quadratic response function

An atomic-orbital based Lagrangian approach for calculating geometric gradients of linear response properties

We present a Lagrangian approach for the calculation of molecular (quadratic) response properties that can be expressed as geometric gradients of a generic linear response function, its poles, and its residues. The approach is implemented within an atomic-orbital-based formalism suitable for linear scaling at the level of self-consistent time-dependent Hartree 12Fock and density functional theory. Among the properties that can be obtained using this formalism are the gradient of the frequency-dependent polarizability (e.g., Raman intensities) and that of the one-photon transition dipole moment (entering the Herzberg 12Teller factors), in addition to the excited-state molecular forces required for excited-state geometry optimizations. Geometric derivatives of ground-state first-order properties (e.g., IR intensities) and excited-state first-order property expressions are also reported as byproducts of our implementation. The one-photon transition moment gradient is the first analytic implementation of the one-photon transition moment derivative at the DFT level of theory. Besides offering a simple solution to overcome phase (hence, sign) uncertainties connected to the determination of the Herzberg 12Teller corrections by numerical derivatives techniques based on independent calculations, our approach also opens the possibility to determine, for example by a mixed analytic 12numerical approach, the one-photon transition dipole Hessian, and thus to investigate vibronic effects beyond the linear Herzberg 12Teller approximation. As an illustrative application, we report a DFT study of the vibronic fine structure of the one-photon (1A1g) 12 (1B2u) transition in the absorption spectrum of benzene, which is Franck 12Condon-forbidden in the electric dipole approximation and hence determined by the Herzberg 12Teller integrals and electronic transition dipole-moment derivatives

Postoperative adjuvant chemotherapy in rectal cancer operated for cure

BACKGROUND: Colorectal cancer is one of the most common types of cancer in the Western world. Apart from surgery - which remains the mainstay of treatment for resectable primary tumours - postoperative (i.e., adjuvant) chemotherapy with 5-fluorouracil (5-FU) based regimens is now the standard treatment in Dukes' C (TNM stage III) colon tumours i.e. tumours with metastases in the regional lymph nodes but no distant metastases. In contrast, the evidence for recommendations of adjuvant therapy in rectal cancer is sparse. In Europe it is generally acknowledged that locally advanced rectal tumours receive preoperative (i.e., neoadjuvant) downstaging by radiotherapy (or chemoradiotion), whereas in the US postoperative chemoradiotion is considered the treatment of choice in all Dukes' C rectal cancers. Overall, no universal consensus exists on the adjuvant treatment of surgically resectable rectal carcinoma; moreover, no formal systematic review and meta-analysis has been so far performed on this subject. OBJECTIVES: We undertook a systematic review of the scientific literature from 1975 until March 2011 in order to quantitatively summarize the available evidence regarding the impact of postoperative adjuvant chemotherapy on the survival of patients with surgically resectable rectal cancer. The outcomes of interest were overall survival (OS) and disease-free survival (DFS). SEARCH METHODS: CCCG standard search strategy in defined databases with the following supplementary search. 1. Rect* or colorect* - 2. Cancer or carcinom* or adenocarc* or neoplasm* or tumour - 3. Adjuv* - 4. Chemother* - 5. Postoper* SELECTION CRITERIA: Randomised controlled trials (RCT) comparing patients undergoing surgery for rectal cancer who received no adjuvant chemotherapy with those receiving any postoperative chemotherapy regimen. DATA COLLECTION AND ANALYSIS: Two authors extracted data and a third author performed an independent search for verification. The main outcome measure was the hazard ratio (HR) between the risk of event between the treatment arm (adjuvant chemotherapy) and the control arm (no adjuvant chemotherapy). The survival data were either entered directly in RevMan or extrapolated from Kaplan-Meier plots and then entered in RevMan. Due to expected clinical heterogeneity a random effects model was used for creating the pooled estimates of treatment efficacy. MAIN RESULTS: A total of 21 eligible RCTs were identified and used for meta-analysis purposes. Overall, 16,215 patients with colorectal cancer were enrolled, 9,785 being affected with rectal carcinoma. Considering patients with rectal cancer only, 4,854 cases were randomized to receive potentially curative surgery of the primary tumour plus adjuvant chemotherapy and 4,367 to receive surgery plus observation. The mean number of patients enrolled was 466 (range: 54-1,243 cases). 11 RCTs had been performed in Western countries and 10 in Japan. All trials used fluoropyrimidine-based chemotherapy (no modern drugs - such as oxaliplatin, irinotecan or biological agents - were tested).Overall survival (OS) data were available in 21 RCTs and the data available for meta-analysis regarded 9,221 patients: of these, 4854 patients were randomized to adjuvant chemotherapy (treatment arm) and 4,367 patients did not receive adjuvant chemotherapy (control arm). The meta-analysis of these RCTs showed a significant reduction in the risk of death (17%) among patients undergoing postoperative chemotherapy as compared to those undergoing observation (HR=0.83, CI: 0.76-0.91). Between-study heterogeneity was moderate (I-squared=30%) but significant (P=0.09) at the 10% alpha level.Disease-free survival (DFS) data were reported in 20 RCTs, and the data suitable for meta-analysis included 8,530 patients. Of these, 4,515 patients were randomized to postoperative chemotherapy (treatment arm) and 4,015 patients received no postoperative chemotherapy (control arm). The meta-analysis of these RCTs showed a reduction in the risk of disease recurrence (25%) among patients undergoing adjuvant chemotherapy as compared to those undergoing observation (HR=0.75, CI: 0.68-0.83). Between-study heterogeneity was moderate (I-squared=41%) but significant (P=0.03).While analyzing both OS and DFS data, sensitivity analyses did not find any difference in treatment effect based on trial sample size or geographical region (Western vs Japanese). Available data were insufficient to investigate on the effect of adjuvant chemotherapy separately in different TNM stages in terms of both OS and DFS. No plausible source of heterogeneity was formally identified, although variability in treatment regimens and TNM stages of enrolled patients might have played a significant role in the difference of reported results. AUTHORS' CONCLUSIONS: The results of this meta-analysis support the use of 5-FU based postoperative adjuvant chemotherapy for patients undergoing apparently radical surgery for non-metastatic rectal carcinoma. Available data do not allow us to define whether the efficacy of this treatment is highest in one specific TNM stage. The implementation of modern anti-cancer agents in the adjuvant setting is warranted to improve the results shown by this meta-analysis. Randomized trials of adjuvant chemotherapy for patients receiving preoperative neoadjuvant therapy are also needed in order to define the role of postoperative chemotherapy in the multimodal treatment of resectable rectal cancer

Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A

Context. Physical processes that govern the star and planet formation sequence influence the chemical composition and evolution of protoplanetary disks. Recent studies allude to an early start to planet formation already during the formation of a disk. To understand the chemical composition of protoplanets, we need to constrain the composition and structure of the disks from whence they are formed. Aims. We aim to determine the molecular abundance structure of the young disk around the TMC1A protostar on au scales in order to understand its chemical structure and any possible implications for disk formation. Methods. We present spatially resolved Atacama Large Millimeter/submillimeter Array observations of CO, HCO+, HCN, DCN, and SO line emission, as well as dust continuum emission, in the vicinity of TMC1A. Molecular column densities are estimated both under the assumption of optically thin emission from molecules in local thermodynamical equilibrium (LTE) as well as through more detailed non-LTE radiative transfer calculations. Results. Resolved dust continuum emission from the disk is detected between 220 and 260 GHz. Rotational transitions from HCO+, HCN, and SO are also detected from the inner 100 au region. We further report on upper limits to vibrational HCN υ2 = 1, DCN, and N2D+ lines. The HCO+ emission appears to trace both the Keplerian disk and the surrounding infalling rotating envelope. HCN emission peaks toward the outflow cavity region connected with the CO disk wind and toward the red-shifted part of the Keplerian disk. From the derived HCO+ abundance, we estimate the ionization fraction of the disk surface, and find values that imply that the accretion process is not driven by the magneto-rotational instability. The molecular abundances averaged over the TMC1A disk are similar to its protostellar envelope and other, older Class II disks. We meanwhile find a discrepancy between the young disk\u27s molecular abundances relative to Solar System objects. Conclusions. Abundance comparisons between the disk and its surrounding envelope for several molecular species reveal that the bulk of planet-forming material enters the disk unaltered. Differences in HCN and H2O molecular abundances between the disk around TMC1A, Class II disks, and Solar System objects trace the chemical evolution during disk and planet formation