Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments

Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC-weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen

Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments

Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC-weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen

Quality control of raw hazelnuts by rapid and non-invasive fingerprinting of volatile compound release

Although hazelnuts are mostly consumed after toasting and mixed with other ingredients, for manufactures it is important to have efficient quality control tests on the raw product that they purchase from farmers and suppliers. This study explores the possibility to predict sensory quality of raw hazelnuts, classified according to industrial sensory evaluation, using volatilome analysis through Proton Transfer Reaction Mass Spectrometry (PTR-MS) rapid fingerprinting. Firstly, the link between volatile markers for different visual and sensory defects was investigated. Uncompliant hazelnuts showed higher concentrations for a larger number of volatile organic compounds (VOCs) than compliant samples, including some key hazelnuts odorants like 5-methyl-4-heptanone, 5-propyldihydro-2(3H)-furanone, octanal, 2,4-nonadienal and hexanal. Secondly, by mixing defective and good quality hazelnuts, the method sensitivity in recognizing defects percentage was determined. For about 13% of the detected mass peaks, the method was able to discriminate samples containing 20% of hazelnuts with unacceptable quality from good quality samples. Finally, unsupervised data clustering of VOCs fingerprints obtained with different precursor ions (H3O+, NO+ and O2+) provided a correct classification rate higher than 90% for all ions. The applied methodology is suitable to support sensory quality control programs of raw hazelnuts in confectionary industries.</p

Diaporthe spp. main candidate causal agent in hazelnut defects in Causasian region

Production of hazelnuts is affected by defects, the incidence of which is year-dependent but also economically damaging. The objectives of the present study were to quantify the incidence of different fungal genera in hazelnuts, and define the causal agent/agents of nut defects. A 4-year study (2013 to 2016) was carried out in the Caucasus region, in an orchard planted in 2008 with hazelnut cv. Anakliuri. Hazelnuts were sampled at early and full ripening stages, observed for defects, and then associated fungi were isolated. Nuts with necrotic spots and internal browning were commonly found, and some collected in 2016 were completely rotted, wet and almost black. Alternaria, Aspergillus, Cladosporium, Colletotrichum, Diaporthe, Fusarium, Penicillium, Pestalotiopsis and Phoma spp. were regularly isolated from diseased and symptomless nuts. Diaporthe spp. was the dominant genus, with increasing incidence from early to full ripening, and were more isolated from defected compared to healthy kernels and in the years with the greatest incidence of defects. Rainfall was associated with the incidence of nut defects. The role of Diaporthe as a key cause hazelnut defects was confirmed by pathogenicity tests. Three isolates from the Diaporthe population were identified as D. eres on the basis of EF, ACT, TUB and ITS loci. This supports the crucial role of climate during the crop-growing season for the development of defects in hazelnuts caused by Diaporthe

Cognitive impairment and dentate gyrus synaptic dysfunction in experimental parkinsonism

Parkinson's disease (PD) is characterized by the progressive degeneration of the nigrostriatal dopaminergic pathway and the emergence of rigidity, tremor, and bradykinesia. Accumulating evidence indicates that PD is also accompanied by nonmotor symptoms including cognitive deficits, often manifested as impaired visuospatial memory

DEFHAZ: A Mechanistic Weather-Driven Predictive Model for Diaporthe eres Infection and Defective Hazelnut Outbreaks

The browning of the internal tissues of hazelnut kernels, which are visible when the nuts are cut in half, as well as the discolouration and brown spots on the kernel surface, are important defects that are mainly attributed to Diaporthe eres. The knowledge regarding the Diaporthe eres infection cycle and its interaction with hazelnut crops is incomplete. Nevertheless, we developed a mechanistic model called DEFHAZ. We considered georeferenced data on the occurrence of hazelnut defects from 2013 to 2020 from orchards in the Caucasus region and Turkey, supported by meteorological data, to run and validate the model. The predictive model inputs are the hourly meteorological data (air temperature, relative humidity, and rainfall), and the model output is the cumulative index (Dh-I), which we computed daily during the growing season till ripening/harvest time. We established the probability function, with a threshold of 1% of defective hazelnuts, to define the defect occurrence risk. We compared the predictions at early and full ripening with the observed data at the corresponding crop growth stages. In addition, we compared the predictions at early ripening with the defects observed at full ripening. Overall, the correct predictions were &gt;80%, with &lt;16% false negatives, which confirmed the model accuracy in predicting hazelnut defects, even in advance of the harvest. The DEFHAZ model could become a valuable support for hazelnut stakeholders

Ecology of Diaporthe eres, the causal agent of hazelnut defects

Diaporthe eres has been recently reported as the causal agent of hazelnut defects, with characteristic brown spots on the kernels surface and internal fruit discoloration. Knowledge regarding the ecology of this fungus is poor but, is critical to support a rationale and effective hazelnut crop protection strategy. Therefore, a study was performed to describe and model the effect of different abiotic factors such as temperature (T, 5 35?C, step 5?C) and water activity (aw 0.83 0.99, step 0.03) regimes on D. eres mycelial growth, pycnidial conidiomata development and asexual spore production during a 60-day incubation period. Alpha conidia germination was tested in the same T range and at different relative humidities (RH = 94, 97 and 100%) over 48 h incubation period. Fungal growth was observed from the first visual observation; regarding pycnidia and cirrhi, their development started after 8 and 19 days of incubation, respectively and increased over time. The optimum T for growth was 20 25?C and for pycnidia and cirrhi development was 30?C; aw 0.98 was optimal for the tested steps of the fungal cycle. The best condition for conidial germination of D. eres was at 25?C with RH = 100%. Quantitative data obtained were fitted using non-linear regression functions (Bete, logistic and polynomial), which provided a very good fit of the biological process (R2 = 0.793 0.987). These functions could be the basis for the development of a predictive model for the infection of D. eres of hazelnuts

Cognitive impairment and dentate gyrus synaptic dysfunction in experimental parkinsonism.

Parkinson's disease (PD) is characterized by the progressive degeneration of the nigrostriatal dopaminergic pathway and the emergence of rigidity, tremor, and bradykinesia. Accumulating evidence indicates that PD is also accompanied by nonmotor symptoms including cognitive deficits, often manifested as impaired visuospatial memory.We studied cognitive performance and synaptic plasticity in a mouse model of PD, characterized by partial lesion of the dopaminergic and noradrenergic inputs to striatum and hippocampus. Sham- and 6-hydroxydopamine-lesioned mice were subjected to the novel object recognition test, and long-term potentiation was examined in the dentate gyrus and CA1 regions of the hippocampus.Bilateral 6-hydroxydopamine lesion reduced long-term but not short-term novel object recognition and decreased long-term potentiation specifically in the dentate gyrus. These abnormalities did not depend on the loss of noradrenaline but were abolished by the antiparkinsonian drug, L-DOPA, or by SKF81297, a dopamine D1-type receptor agonist. In contrast, activation of dopamine D2-type receptors did not modify the effects produced by the lesion. Blockade of the extracellular signal-regulated kinases prevented the ability of SKF81297 to rescue novel object recognition and long-term potentiation.These findings show that partial dopamine depletion leads to impairment of long-term recognition memory accompanied by abnormal synaptic plasticity in the dentate gyrus. They also demonstrate that activation of dopamine D1 receptors corrects these deficits, through a mechanism that requires intact extracellular signal-regulated kinases signaling