Delimiting morphological and volumetric elements of cave surveys as analogues for paleokarst reservoir modelling – A case study from the Maaras cave system, northern Greece

Active karst systems can offer good analogues for paleokarst reservoir modelling as they can provide links between present karst system geometries and the final reservoir architecture. Although clastic sediments are a characteristic and commonly conspicuous component of modern karst systems, their impact on the surveyed cave morphology has received limited attention. Here we address this topic by investigating the spatial and volumetric distribution of clastic sediments in a large karst cave hosting an active fluvial channel in northern Greece and discretize these in a geocellular framework. Mapping of cave floor sediment-types was supplemented by local stratigraphic logging of relict sediment terraces and electrical resistivity tomography in parts of the cave. Four resistivity groups were identified and interpreted as low- and high-porosity siliciclastic sediments, interbedded marble clasts, and host rock (marble). Sediment infill thickness ranges from 25 m to >45 m at the time of measurement; corresponding to a minimum of 64–95% of the cross-sectional area of the karst cavity in the surveyed part. These observations demonstrate that under certain circumstances, allochthonous siliciclastic sediments can form a significant volumetric component in karst systems and, by extension, in paleokarst reservoirs originating from similar karstic systems. This highlights the importance of understanding the context, organization and development of the initial karst system when characterizing paleokarst reservoirs. Mapping of sediment thickness is not usually carried out during cave surveys, which primarily focus on recording open cavities accessible to man. This implies that survey data concerning the shape and volume of cave systems and statistics compiled and derived from them should be handled with care when applied to paleokarst reservoir modelling.publishedVersio

Archival Information Package (AIP) Draft Specification

This report builds on the overview of existing solutions for AIPs given in D4.1. It describes a blueprint for the structure of an AIP format following from the state of the art described there. As an AIP has a potentially unlimited life span, however, we augment the presentation of the format of the physical file representing the AIP by a discussion of how such an AIP may keep an unchanged identity, while its physical representation may change over time. A “Pan-European AIP format” is supposed to handle essentially each type of digital content a user may want it to contain. It is obviously impossible, to describe in a format document, how content not yet known will be handled. The document, therefore, also contains a chapter on the way in which this format is embedded into the technical workflow within which an AIP exists

Glutamate-system defects behind psychiatric manifestations in a familial hemiplegic migraine type 2 disease-mutation mouse model

Migraine is a complex brain disorder, and understanding the complexity of this prevalent disease could improve quality of life for millions of people. Familial Hemiplegic Migraine type 2 (FHM2) is a subtype of migraine with aura and co-morbidities like epilepsy/seizures, cognitive impairments and psychiatric manifestations, such as obsessive-compulsive disorder (OCD). FHM2 disease-mutations locate to the ATP1A2 gene encoding the astrocyte-located α(2)-isoform of the sodium-potassium pump (α(2)Na(+)/K(+)-ATPase). We show that knock-in mice heterozygous for the FHM2-associated G301R-mutation (α(2)(+/G301R)) phenocopy several FHM2-relevant disease traits e.g., by mimicking mood depression and OCD. In vitro studies showed impaired glutamate uptake in hippocampal mixed astrocyte-neuron cultures from α(2)(G301R/G301R) E17 embryonic mice, and moreover, induction of cortical spreading depression (CSD) resulted in reduced recovery in α(2)(+/G301R) male mice. Moreover, NMDA-type glutamate receptor antagonists or progestin-only treatment reverted specific α(2)(+/G301R) behavioral phenotypes. Our findings demonstrate that studies of an in vivo relevant FHM2 disease knock-in mouse model provide a link between the female sex hormone cycle and the glutamate system and a link to co-morbid psychiatric manifestations of FHM2

Studies of association of AGPAT6 variants with type 2 diabetes and related metabolic phenotypes in 12,068 Danes

BACKGROUND: Type 2 diabetes, obesity and insulin resistance are characterized by hypertriglyceridemia and ectopic accumulation of lipids in liver and skeletal muscle. AGPAT6 encodes a novel glycerol-3 phosphate acyltransferase, GPAT4, which catalyzes the first step in the de novo triglyceride synthesis. AGPAT6-deficient mice show lower weight and resistance to diet- and genetically induced obesity. Here, we examined whether common or low-frequency variants in AGPAT6 associate with type 2 diabetes or related metabolic traits in a Danish population. METHODS: Eleven variants selected by a candidate gene approach capturing the common and low-frequency variation of AGPAT6 were genotyped in 12,068 Danes from four study populations of middle-aged individuals. The case–control study involved 4,638 type 2 diabetic and 5,934 glucose-tolerant individuals, while studies of quantitative metabolic traits were performed in 5,645 non-diabetic participants of the Inter99 Study. RESULTS: None of the eleven AGPAT6 variants were robustly associated with type 2 diabetes in the Danish case–control study. Moreover, none of the AGPAT6 variants showed association with measures of obesity (waist circumference and BMI), serum lipid concentrations, fasting or 2-h post-glucose load levels of plasma glucose and serum insulin, or estimated indices of insulin secretion or insulin sensitivity. CONCLUSIONS: Common and low-frequency variants in AGPAT6 do not significantly associate with type 2 diabetes susceptibility, or influence related phenotypic traits such as obesity, dyslipidemia or indices of insulin sensitivity or insulin secretion in the population studied

Anatomical Alterations of the Visual Motion Processing Network in Migraine with and without Aura

BACKGROUND: Patients suffering from migraine with aura (MWA) and migraine without aura (MWoA) show abnormalities in visual motion perception during and between attacks. Whether this represents the consequences of structural changes in motion-processing networks in migraineurs is unknown. Moreover, the diagnosis of migraine relies on patient's history, and finding differences in the brain of migraineurs might help to contribute to basic research aimed at better understanding the pathophysiology of migraine. METHODS AND FINDINGS: To investigate a common potential anatomical basis for these disturbances, we used high-resolution cortical thickness measurement and diffusion tensor imaging (DTI) to examine the motion-processing network in 24 migraine patients (12 with MWA and 12 MWoA) and 15 age-matched healthy controls (HCs). We found increased cortical thickness of motion-processing visual areas MT+ and V3A in migraineurs compared to HCs. Cortical thickness increases were accompanied by abnormalities of the subjacent white matter. In addition, DTI revealed that migraineurs have alterations in superior colliculus and the lateral geniculate nucleus, which are also involved in visual processing. CONCLUSIONS: A structural abnormality in the network of motion-processing areas could account for, or be the result of, the cortical hyperexcitability observed in migraineurs. The finding in patients with both MWA and MWoA of thickness abnormalities in area V3A, previously described as a source in spreading changes involved in visual aura, raises the question as to whether a “silent” cortical spreading depression develops as well in MWoA. In addition, these experimental data may provide clinicians and researchers with a noninvasively acquirable migraine biomarker