KINEMATIC ANALYSIS EVOLUTION OF EXTENDED LANDSLIDES: TWO CASE STUDIES FROM WESTERN GREECE

Οι κατολισθήσεις αποτελούν τον πιο συχνό κίνδυνο στην Δυτική Ελλάδα, μαζί με τους σεισμούς και τις πυρκαγιές. Έχουν πραγματοποιηθεί πολλές μελέτες με σκοπό την μελέτη των φαινομένων καθώς επίσης και καταγραφή τους σε χάρτες. Στην παρούσα εργασία αναλύονται δύο από τις πλέον καλά μελετημένες κατολισθήσεις ως προς την εξέλιξή τους. Οι κατολισθήσεις της Παναγοπούλας και της Καρυάς αποτελούν δύο αντιπροσωπευτικές θέσεις μακράς παρακολούθησης μέσω αποκλισιομετρικών μετρήσεων. Ο παράγοντας εναύσματος και στις δύο περιπτώσεις είναι οι έντονες βροχοπτώσεις. Η κύρια τεχνικογεωλογική ενότητα που σχετίζεται με αυτές είναι ο σχηματισμός του φλύσχη. Οι αποκλισιομετρικές μετρήσεις για ένα μεγάλο χρονικό διάστημα αναλύονται και σχεδιάζονται τυπικά διαγράμματα μετακινήσεων. Γίνεται χρήση ενός απλού στατιστικού μοντέλου που περιλαμβάνει κανονικοποίηση των δεδομένων κατά τη διάρκεια συγκεκριμένων φάσεων μετακίνησης με βασικό σκοπό να αναγνωριστούν τα κινηματικά χαρακτηριστικά της μετακίνησης και να εκτιμηθούν οι επικρατούσες ταχύτητες.Two of the most well known historical landslide occurrences are analyzed and their temporal evolution is presented. The sites of Panagopoula and Karya are often referred as the most representative cases of long term ground displacements based on inclinometer monitoring data. Regarding these cases, the heavy rainfalls constitute the main controlling (triggering) factor, while flysch is the critical landslide-prone formation which significantly contributes to landsliding. The inclinometer data through a long time period were analyzed and typical movement diagrams were compiled. A simple statistical model including data normalization through several active stages (phases) of movement is used to identify the common kinematic features as well as to estimate the velocity trend type of movement

RhoGEF9 splice isoforms influence neuronal maturation and synapse formation downstream of α2 GABAA receptors

In developing brain neuronal migration, dendrite outgrowth and dendritic spine outgrowth are controlled by Cdc42, a small GTPase of the Rho family, and its activators. Cdc42 function in promoting actin polymerization is crucial for glutamatergic synapse regulation. Here, we focus on GABAergic synapse-specific activator of Cdc42, collybistin (CB) and examine functional differences between its splice isoforms CB1 and CB2. We report that CB1 and CB2 differentially regulate GABAergic synapse formation in vitro along proximal-distal axis and adult-born neuron maturation in vivo. The functional specialization between CB1 and CB2 isoforms arises from their differential protein half-life, in turn regulated by ubiquitin conjugation of the unique CB1 C-terminus. We report that CB1 and CB2 negatively regulate Cdc42; however, Cdc42 activation is dependent on CB interaction with gephyrin. During hippocampal adult neurogenesis CB1 regulates neuronal migration, while CB2 is essential for dendrite outgrowth. Finally, using mice lacking Gabra2 subunit, we show that CB1 function is downstream of GABAARs, and we can rescue adult neurogenesis deficit observed in Gabra2 KO. Overall, our results uncover previously unexpected role for CB isoforms downstream of α2-containing GABAARs during neuron maturation in a Cdc42 dependent mechanism

RhoGEF9 splice isoforms influence neuronal maturation and synapse formation downstream of alpha 2 GABA(A) receptors

In developing brain neuronal migration, dendrite outgrowth and dendritic spine outgrowth are controlled by Cdc42, a small GTPase of the Rho family, and its activators. Cdc42 function in promoting actin polymerization is crucial for glutamatergic synapse regulation. Here, we focus on GABAergic synapse-specific activator of Cdc42, collybistin ( CB) and examine functional differences between its splice isoforms CB1 and CB2. We report that CB1 and CB2 differentially regulate GABAergic synapse formation in vitro along proximal-distal axis and adult-born neuron maturation in vivo. The functional specialization between CB1 and CB2 isoforms arises from their differential protein half-life, in turn regulated by ubiquitin conjugation of the unique CB1 C-terminus. We report that CB1 and CB2 negatively regulate Cdc42; however, Cdc42 activation is dependent on CB interaction with gephyrin. During hippocampal adult neurogenesis CB1 regulates neuronal migration, while CB2 is essential for dendrite outgrowth. Finally, using mice lacking Gabra2 subunit, we show that CB1 function is downstream of GABA(A)Rs, and we can rescue adult neurogenesis deficit observed in Gabra2 KO. Overall, our results uncover previously unexpected role for CB isoforms downstream of alpha 2-containing GABA(A)Rs during neuron maturation in a Cdc42 dependent mechanism.Peer reviewe

Subclinical autonomic dysfunction in patients with beta-thalassemia

We electrophysiologically evaluated the autonomic function (AF) in a consecutive series of patients with beta-thalassemia and in normal individuals. Six quantitative autonomic function tests (AFTs) were used: tilt test, hand grip test and sympathetic skin response for sympathetic function; R-R interval, inspiration-expiration difference and 30/15 ratio for parasympathetic function. The prevalence of impaired AF was higher in beta-thalassemia patients (13%, n = 5) than in control subjects (0%, n = 0; p = 0.026). Subclinical autonomic dysfunction appeared to be more prevalent in beta-thalassemia patients compared to controls in our series. Further independent validation of this finding is required in larger cohorts of beta-thalassemia patients. © Springer-Verlag 2012

Noradrenaline release from the locus coeruleus shapes stress-induced hippocampal gene expression

Exposure to an acute stressor triggers a complex cascade of neurochemical events in the brain. However, deciphering their individual impact on stress-induced molecular changes remains a major challenge. Here, we combine RNA sequencing with selective pharmacological, chemogenetic, and optogenetic manipulations to isolate the contribution of the locus coeruleus-noradrenaline (LC-NA) system to the acute stress response in mice. We reveal that NA release during stress exposure regulates a large and reproducible set of genes in the dorsal and ventral hippocampus via beta-adrenergic receptors. For a smaller subset of these genes, we show that NA release triggered by LC stimulation is sufficient to mimic the stress-induced transcriptional response. We observe these effects in both sexes, and independent of the pattern and frequency of LC activation. Using a retrograde optogenetic approach, we demonstrate that hippocampus-projecting LC neurons directly regulate hippocampal gene expression. Overall, a highly selective set of astrocyte-enriched genes emerges as key targets of LC-NA activation, most prominently several subunits of protein phosphatase 1 (Ppp1r3c, Ppp1r3d, Ppp1r3g) and type II iodothyronine deiodinase (Dio2). These results highlight the importance of astrocytic energy metabolism and thyroid hormone signaling in LC-mediated hippocampal function and offer new molecular targets for understanding how NA impacts brain function in health and disease.ISSN:2050-084

Noradrenaline release from the locus coeruleus shapes stress-induced hippocampal gene expression

Exposure to an acute stressor triggers a complex cascade of neurochemical events in the brain. However, deciphering their individual impact on stress-induced molecular changes remains a major challenge. Here, we combine RNA sequencing with selective pharmacological, chemogenetic, and optogenetic manipulations to isolate the contribution of the locus coeruleus-noradrenaline (LC-NA) system to the acute stress response in mice. We reveal that NA release during stress exposure regulates a large and reproducible set of genes in the dorsal and ventral hippocampus via β-adrenergic receptors. For a smaller subset of these genes, we show that NA release triggered by LC stimulation is sufficient to mimic the stress-induced transcriptional response. We observe these effects in both sexes, and independent of the pattern and frequency of LC activation. Using a retrograde optogenetic approach, we demonstrate that hippocampus-projecting LC neurons directly regulate hippocampal gene expression. Overall, a highly selective set of astrocyte-enriched genes emerges as key targets of LC-NA activation, most prominently several subunits of protein phosphatase 1 (Ppp1r3c, Ppp1r3d, Ppp1r3g) and type II iodothyronine deiodinase (Dio2). These results highlight the importance of astrocytic energy metabolism and thyroid hormone signaling in LC-mediated hippocampal function and offer new molecular targets for understanding how NA impacts brain function in health and disease

Financial crisis and energy consumption: A household survey in Greece

Δημοσίευση σε επιστημονικό περιοδικόSummarization: This research aims to investigate, analyze and characterize the relation between the economic crisis and energy consumption in Greece. A survey held in the spring and summer of 2012 collected data of the heating energy consumption for 2010–2011 and 2011–2012, from 598 households via a questionnaire. Comparing the 2010–11 winter to the harsher winter of 2011–12 showed that inhabitants consumed less energy during the winter of 2011–12 because of the rapid economic degradation. Important conclusions were drawn regarding the energy consumption of the households which during the harsh winter 2011–12 was 37% less than expected. Cluster analysis rendered two distinct clusters: three fourths of the households belonged to the lower income group that lived in a smaller space, had half the income and consumed more specific energy compared to the high income group, although much less than expected based on the degree hours of the second winter. One out of three higher-income and one out of four lower-income households adopted some conservation measures after the first winter while 2% of the higher income households and 14% of the lower-income households were below the fuel poverty threshold. Directions for further research include monitoring of low income households with sensors.Παρουσιάστηκε στο: Energy and Building

Protein half-life of V5-CB1 and V5-CB2 splice isoforms differ.

<p><b>(A)</b> Protein stability of V5-CB1_SH3+ was determined by collecting the protein samples at 0, 1, 2, 4 and 8 hours in the presence of cyclohexamide (CHX) (0.1mM) and half-life relative to actin was plotted. The t_1/2 and R² values were determined (inset). <b>(B)</b> Protein half-life of CB2_SH3+ isoform. <b>(C)</b> Protein half-life of CB1_SH3- in HEK-293T cells. <b>(D)</b> Protein half-life of CB2_SH3- isoform in HEK-293T cells. CB1_SH3- shows the shortest half-life (1.8 hr), while CB2_SH3- has the longest half-life (7.294 hr). <b>(E)</b> Protein half-life of mCherry-CB1_SH3- in primary hippocampal neuron is similar to HEK-293T cells. <b>(F)</b> CB1 isoform C-terminal amino acid sequence with specific Ub lysine residues marked in red. <b>(G-J)</b> The predicted K491R/K492R ubiquitin residues in CB1 were mutated Lys/Arg and the protein stability of the mutants was determined. The ubiquitin site mutants have a longer half-life compared to the WT counterparts. <b>(I-J)</b> CBΔC_SH3+ and CBΔC_SH3- C-terminus deletion mutations show similar protein half-life.</p

V5-CB1 splice isoforms enhance eGFP-gephyrin clustering along proximal-distal axis.

<p><b>(A)</b> Cartoon of various CB isoforms and deletion mutations used in the current study. <b>(B-F)</b> 8+7 DIV neurons co-transfected with either V5-CB1_SH3+, V5-CB1_SH3-, V5-CB2_SH3+ or V5-CB2_SH3- isoform (blue) and eGFP-gephyrin (green) and stained for presynaptic marker VGAT (red). Alterations in the morphology of eGFP-gephyrin synaptic clusters was observed. <b>(B-F, lower panels)</b> zoom of dendritic proximal or distal dendritic segment showing eGFP-gephyrin clustering and vGAT co-localization. The localization of eGFP-gephyrin clusters with γ2 GABA_AR subunit was also observed. <b>(G-I)</b> Quantification of eGFP-gephyrin synaptic cluster density per 20 μm dendrite (DIV 8+7) at proximal and distal dendritic segments of neurons co-expressing eGFP-gephyrin and mCherry-CB1/2 isoforms. Scale bar 10μm and 5 μm. Statistical analysis for cluster density; One-way ANOVA, Bonferonni post-hoc test, p = 0.85; size analysis: Kruskal-Wallis non parametric test, Dunn's multiple comparison test p<0.0001.</p