Search

Deciphering the genetic architecture of cardiac disorders is of fundamental importance but their underlying complexity is a major hurdle. Drosophila has gained importance as a useful model to study heart development and function and allows the analysis of organismal traits in a physiologically relevant and accessible system. Our aim was to (i) identify in flies the variants associated to natural variations of cardiac performances among a natural population, (ii) decipher how these variants interact with each other and with the environment to impact cardiac traits, (iii) gain insights about the molecular and cellular processes affected, (iv) determine whether the genetic architecture of cardiac disorders is conserved with humans. We used the Drosophila Genetic Reference Panel, a community resource of sequenced inbred lines. Genome Wide Associations (GWA) for single markers and epistatic interactions were analyzed on cardiac traits related to rhythm and contractility. Genetic networks were unraveled and extensively validated in vivo. Non-coding variants were used to map potential regulatory non-coding regions and to predict Transcription Factors (TFs) binding sites. Cognate TFs were validated by heart specific knockdown. Natural variations of cardiac traits variance revealed unique features of the phenotypic plasticity of cardiac performance. Importantly, correlations between genes associated to GWAS for cardiac traits both in flies and humans supported conservation of the genetic architecture of cardiac disorders from arthropods to mammals. In addition, several conserved genes and pathways were validated in human iPSC-derived cardiomyocytes. We provide an in-depth analysis of the genetic architecture of natural variations of cardiac performance in flies. Our data may guide the analysis of cardiac disorders in humans. [ABSTRACT FROM AUTHOR]

Drosophila, the simplest model system with a beating heart, has tremendous advantages for the identification and validation of genetic factors affecting heart development, function and aging. Our project aims to analyse the genetic architecture of the natural variation of heart function in Drosophila and to identify its main characteristics. In particular, we want to take advantage of this model system to disentangle the complex relationship between genetic and environmental factors influencing these complex traits. Cardiac performances were analysed in the Drosophila Genetic Reference Panel (DGRP), and Genome Wide Association Studies (GWAS) were conducted to identify variants associated to several cardiac traits (rate, rhythm, cardiac output, fractional shortening, etc). The compendium of variants and associated genes identified were studied using approaches based on the analysis of gene and protein interaction networks. Genetic and protein networks analyses pointed towards several signalling pathways involved, that were further validated in vivo by targeted gene knockdown. Phenotypic variance among genetically identical individuals was also analysed and associated variants were compared to those affecting variations of phenotypic mean, revealing that distinct though overlapping gene networks were affected. In addition, our results show that more than 90% of variants are located within non-coding regions, and we characterized and validated some aspects of the transcriptional regulatory network affected. We provide a comprehensive characterization of population scale diversity of cardiac traits and of their genetic basis. Our work may provide a framework to interpret similar data from highers eukaryotes, including humans. [ABSTRACT FROM AUTHOR]

The article presents abstracts on topics related to nuclear cardiology, including assessment of the effect of cardiac resynchronization therapy on ventricular delays by multiharmonic analysis of radionuclide angiography, the correlation between electron beam computed tomography with stress single photon emission computed tomography, as well as a comparison between lipid and scintigraphic responses accompanying statin therapy.

Consumer acceptability of fresh-cut apples is affected by texture characteristics, mainly by crispness attribute. The use of combined instrumental acoustic-mechanical techniques and the measurement of the absorption coefficient at 670 nm (μ a 670) by time-resolved reflectance spectroscopy (TRS) have been shown useful to assess fruit crispness and the maturity degree. The aim of this work was to evaluate the influence of the maturity degree measured by TRS, modified atmosphere and anti-browning dipping on the texture of fresh-cut apples as measured by means of an instrumental mechanical-acoustic test and the rheological behavior of the cell wall material. Apples were measured at harvest by TRS at 670 nm, ranked on the basis of decreasing μ a 670 (increasing maturity) and classified as less mature (LeM), medium mature and more mature (MoM). Only LeM and MoM apples were peeled and cut, half of them were dipped in the antibrowning solution and the other were not dipped. All samples were packed using air or 80% Ar + 20% CO 2 modified atmosphere (MA). Ethylene concentration and instrumental mechanical-acoustic characteristic were evaluated after 1, 4, 8, 11 and 15 d of refrigerated storage (4 °C). The rheological behavior of cell wall material was evaluated after 1 and 15 d. LeM and MoM samples showed a different ethylene evolution for fresh-cut apples packed in air. The mechanical-acoustic results showed that the maturity degree influenced the texture significantly, with LeM apples firmer and more rigid and producing also a higher number of acoustic events with more elevated maximum signal amplitude than MoM fruit. However maturity degree did not affect the evolution of texture throughout storage. Both dipping treatment and MA did not affect texture clearly. The rheological behavior of the cell wall material suggested an increase of elastic behavior with storage time. In order to obtain a fresh-cut product with homogeneous texture characteristics, these results suggest that it would be beneficial to process fruits of a homogeneous maturity class, which could be achieved by sorting using TRS. [ABSTRACT FROM AUTHOR]

Abstract: Time-resolved reflectance spectroscopy (TRS) studies have shown that in apples the absorption coefficient (μ a) at 630nm is linked to fruit maturity, whereas the scattering coefficient () is related to fruit texture not only at a macroscopic level but also to cell wall and middle lamella pectic composition. This work aimed at studying the classification models based on the optical properties of absorption and scattering measured by TRS in order to select apples with distinctive quality and sensory characteristics at consumption. After 6 months’ storage in normal and controlled atmosphere plus 7d of post-storage shelf life at 20°C, ‘Jonagored’ apples were measured for TRS optical properties (μ a and ) at 630, 670, 750 and 780nm, and for quality characteristics (firmness, stiffness, percent juice, soluble solids content, titratable acidity, background and red side colour parameters) and assessed by a sensory panel for seven attributes (firm, crispy, mealy, juicy, sour, sweet, aromatic). Data of quality and sensory characteristics and of optical properties were processed together by Principal Component Analysis. According to sensory intensity scores, apples were either divided into three classes (low, medium, high intensity) separately for every attribute, or clustered into five groups, each one representing a specific sensory profile. The optical coefficients were used as variables to classify fruit according to either the class of intensity for every attribute, or according to the sensory profile. All the models showed better classification performances when also including selected absorption coefficients, as well as scattering coefficients. The performance of the classification models ranged from 57.3% for the juicy model to 71.9% for the mealy one. The model sorting apples into five different sensory profiles showed a lower percentage of well-classified fruit if compared to the classification models developed for each sensory descriptor, even if it was able to correctly classify almost 70% of fruit having either a mealy-dry texture without flavour or a not-mealy-juicy texture with a moderate flavour. [Copyright &y& Elsevier]

Abstract: Time-resolved reflectance spectroscopy (TRS) studies on fruit have shown that the absorption coefficient (μ a) at 670nm is a good maturity index and that the scattering coefficient () at 780nm allows an insight into the textural properties of apples. This work aimed at studying the relationship between the polyuronide pattern, firmness and TRS optical properties (μ a and ) at 630, 670, 750 and 780nm measured in ‘Jonagored’ apples at harvest, after 6months’ storage in normal (NA) and controlled atmosphere (CA), and after 7days of post-storage shelf life at 20°C. Results showed that fruit of different TRS maturity class had a different polyuronide content, even if their firmness was not different: ‘less mature’ (high μ a630) fruit compared to ‘more mature’ (low μ a630) ones showed at harvest higher total galacturonic acid (GA) content, residue insoluble pectin (RIP) and protopectin index (PI), and lower GA content in oxalate-soluble pectin (OSP) fraction, indicating a less advanced breakdown of insoluble protopectins to soluble pectins. The μ a630 and μ a670 were correlated to alcohol-insoluble substances (AIS) and GA content in RIP measured after storage: as maturity increased, GA decreased in RIP, showing pectin solubilisation. AIS, water-soluble pectin (WSP), RIP and PI measured after storage were highly correlated to scattering coefficients measured after storage. Generally, with increasing , AIS and GA in WSP increased while firmness, RIP and PI decreased. CA apples were characterised by lower values than NA ones, along with lower WSP and OSP and higher total GA, RIP and PI. [Copyright &y& Elsevier]

Objective: Electroencephalography (EEG) source reconstruction is becoming recognized as a useful technique to non-invasively localize the epileptic focus. Whereas, large array magnetoencephalography (MEG) systems are available since quite some time, application difficulties have previously prevented multichannel EEG recordings. Recently, however, EEG systems which allow for quick (10–20 min) application of, and recording from, up to 125 electrodes have become available. The purpose of the current investigation was to systematically compare the accuracy of epileptic source localization with high electrode density to that obtained with sparser electrode setups.Methods: Interictal epileptiform activity was recorded with 123 electrodes in 14 epileptic patients undergoing presurgical evaluation. Each single epileptiform potential was down sampled to 63 and 31 electrodes, and a distributed source model (EPIFOCUS) was used to reconstruct the sources with the 3 different electrode configurations. The localization accuracy with the 3 electrode setups was then assessed, by determining the distance from the inverse solution, maximum of each single spike to the epileptogenic lesion.Results: In 9/14 patients, the distance from the EEG source to the lesion was significantly smaller with 63 than with 31 electrodes, and increasing the number of electrodes to 123 increased this number of patients from 9 to 11. Simulations confirmed the relation between the number of electrodes and localization accuracy.Conclusions: The results illustrate the necessity of multichannel EEG recordings for high source location accuracy in epileptic patients. [Copyright &y& Elsevier]

Abstract: The absorption coefficient μ a measured at 670nm in fruit pulp at harvest by time-resolved reflectance spectroscopy (TRS) has been shown to be a good maturity index for early nectarine cultivars. By including individual fruit maturity as a biological shift factor (BSF) into a kinetic model for softening it is possible to select fruit with different shelf-life potential. The BSF approach combined with TRS measurement and kinetic modeling of firmness was applied to a late maturing nectarine cultivar (‘Morsiani 90’), ripened at 20°C after harvest or after storage at 0°C and 4°C, the latter conditions inducing chilling injury. At harvest the absorption coefficient μ a had low values and low variability, indicating advanced maturity, while firmness was similar to that of early cultivars. The softening model took into account these differences, showing parameters similar to those of the early cultivars with the exception of the softening rate which was 2–6 times lower, indicating a slower softening in ‘Morsiani 90’ fruit. Decay of μ a at 20°C was also slower. Softening continued during storage at 4°C, but not at 0°C. After storage at 0°C softening was resumed similarly to non-stored fruit, but with much variability. Fruit stored at 4°C, which showed chilling injury, had a softening rate at 20°C significantly higher than that of 0°C fruit. It is suggested that the same changes in cell wall metabolism which induce the appearance of chilling injury also affect firmness and increase softening rate. [Copyright &y& Elsevier]

Abstract: Nectarine fruit after cold storage soften normally, but become dry instead of juicy and can develop flesh browning, bleeding and a gel-like or glassy formation of the flesh near the pit. An experiment was conducted to see if time-resolved reflectance spectroscopy could distinguish these internal disorders non-destructively. The optical parameters of absorption coefficient (μ a) and reduced scattering coefficient (μ′s) were measured at 670nm and 780nm, on nectarine (Prunus persica cv. Morsiani 90) fruit held at 20°C after harvest or after 30 d of storage at 0°C or 4°C. Each day for 5 d 30 fruit were examined both non-destructively and destructively. Other measurements were firmness with a penetrometer, peel colour on the blush and non-blush side, expressible juice, weight loss, and visual rating of internal browning, bleeding, and gel. The fruit had been sorted at harvest according to the value of μ a670 so that each batch had a similar spread of fruit maturity. More mature fruit (lower μ a670 values) developed internal browning and bleeding with more severe symptoms compared to less mature ones (higher μ a670 values). It was found that μ a780 could distinguish healthy fruits from the chilling injured ones. Canonical discriminant analysis indicated that fruit without cold storage had low μ a780, less water loss, low firmness, but high μ a670 and high expressible juice compared with cool stored fruit. Fruit cool stored at 4°C had high μ a780 and less expressible juice, lower water loss and lower firmness compared with fruit cool stored at 0°C. It was concluded that time resolved reflectance spectroscopy could detect internal woolliness and internal browning in nectarines after storage. [ABSTRACT FROM AUTHOR]

Abstract: The maturity of nectarines at harvest can be assessed by measuring the absorption coefficient at 670nm (μ a) with the non-destructive technique of time-resolved reflectance spectroscopy (TRS). A kinetic model links μ a, converted into the biological shift factor (BSF), to firmness decrease during ripening; in this way the firmness decay model includes the variations in maturity at harvest, thereby allowing prediction of shelf-life for individual fruit. In order to study how this methodology could be practically used at the time of harvest, when μ a can be measured non-destructively on all fruit, while the destructive measurement of firmness can only be done on a small sample, various firmness decay models were developed using either data at harvest or within 1–2 d after harvest from previous experimental research with nectarines carried out over a 5-year period. These models were then tested for prediction and classification ability by comparing the predicted firmness and class of usability to the actual ones measured during ripening and their performance compared to that of models based on data during the whole shelf-life. Our results suggest that the methodology might be used as a management tool in the nectarine supply chain. Independently from the actual softening rate, the classification at harvest based on μ a is able to segregate fruit of different quality and maturity according to their softening behaviour during shelf-life. Among the various models, those estimated using data at harvest and after 24h of shelf-life had better performance than those based only on data at harvest. In the 2002 and 2005 seasons, this model showed a classification ability very close to that of models based on data during the whole shelf-life. However, its performance in the 2004 season was not so good, because it could not take into account the influence of cold storage periods prior to shelf-life. All the steps necessary to apply this methodology are detailed. [Copyright &y& Elsevier]

Abstract: The maturity at harvest of nectarines can be assessed with the novel technique of time-resolved reflectance spectroscopy (TRS) measuring the light absorption at 670nm in the fruit flesh. A kinetic model was developed that links this absorption coefficient (μ a), expressed as the biological shift factor, to firmness decrease during ripening. The model thus includes the variations in maturity at harvest of the individual fruit. In non-linear regression analyses of data from four different seasons, the explained part ranged from 81 to 92% for cv ‘Spring Bright’. The kinetic parameters values obtained were highly similar in different seasons. The results suggest that in nectarines the degreening of fruit flesh, expressed as TRS absorption at 670nm, is synchronised with the softening. The distribution of μ a was skewed, but that of the biological shift factor, derived from μ a, was normal. By measuring the colour of fruit flesh with the non-destructive and very rapid TRS technique, and applying the model parameters, individual fruit can be graded at harvest into classes of usability, selecting fruit with different ripening stages for different market segments and predicting their softening time, thereby guaranteeing sufficient firmness to transport the fruit and sufficient ripening potential to reach good eating quality upon arrival in the receiving regions or countries. Consumers therefore will be more satisfied, encouraging them to repeated purchase. Retailers and wholesalers will be more satisfied since fruit unfit for sale not longer needs to be transported. [Copyright &y& Elsevier]

Abstract: The exquisite sensitivity of the human visual system to form-from-motion (FfM) cues is well documented. However, identifying the neural correlates of this sensitivity has proven difficult, particularly determining the respective contributions of different motion areas in extrastriate visual cortex. Here we measured visual FfM perception and more elementary visual motion (VM) perception in a group of 32 patients suffering from acute posterior brain damage, and performed MRI-based lesion analysis. Our results suggest that severe FfM perception deficits without an associated deficit of VM perception are due to damage to ventral occipito-temporal cortex (VOT), whereas associated deficits of FfM and VM perception are due to damage either in proximity to area MT+/V5 or an area including lateral occipital complex (LOC) and VOT. These data suggest the existence of at least three functionally and anatomically distinct regions in human visual cortex that process FfM signals. [Copyright &y& Elsevier]

Abstract: Time-resolved reflectance spectroscopy (TRS), allows for the complete optical characterization (in terms of the absorption and scattering coefficients) of diffusive media such as fruit, in the spectral range 600–1100nm, probing a volume to a depth of about 2cm. The hypothesis was made that the absorption coefficient at 670nm (μ a), near the chlorophyll peak, could be an index of fruit maturity at harvest. The aim of this research was to model nectarine softening for fruit of different maturity at harvest, as assessed by μ a. Nectarine fruit of two sizes (A and B) were picked in 2002, 2003 (cv ‘Spring Bright’) and 2004 (cv ‘Ambra’), measured by TRS at harvest on two opposite sides and ranked by decreasing μ a averaged per fruit (increasing maturity). Fruit were stored at 0°C for 3, 10 and 6 days, then at 20°C for 79, 120 and 117h in 2002, 2003 and 2004, respectively. Firmness was measured by pressure test (8mm tip) during shelf life, on two sides of each fruit, and then averaged. Softening at 20°C followed a logistic model as a function of μ a at harvest and of time at 20°C (adjusted R 2 =0.85 in ‘Spring Bright’ and 0.75 in ‘Ambra’). The effects of fruit size and cold storage were negligible. The absorption coefficient μ a explained 13–34% of the variation of firmness. Fruit with different μ a at harvest softened with the same sigmoidal pattern in time, which was shifted earlier in low μ a fruit, and later in high μ a fruit. μ a accounted for the time shift in softening of individual fruit within the same batch. The value of μ a can be regarded as an index of the biological age of fruit. By using this model, it is possible to predict individual fruit softening rates at 20°C. [Copyright &y& Elsevier]

The article discusses the seroprevalence of Q-fever, brucellosis and leptospirosis in the farmers of Bari, southern Italy. The factors responsible for zoonotic infection in farmers are frequent contact with domestic animals and poor animal sanitation. Almost 40 cases of human brucellosis from Apulia, southern Italy, and 681 from other Italian regions were reported to the Italian Ministry of Health in 2005.