The resting microstate networks (RMN): cortical distributions, dynamics, and frequency specific information flow

A brain microstate is characterized by a unique, fixed spatial distribution of electrically active neurons with time varying amplitude. It is hypothesized that a microstate implements a functional/physiological state of the brain during which specific neural computations are performed. Based on this hypothesis, brain electrical activity is modeled as a time sequence of non-overlapping microstates with variable, finite durations (Lehmann and Skrandies 1980, 1984; Lehmann et al 1987). In this study, EEG recordings from 109 participants during eyes closed resting condition are modeled with four microstates. In a first part, a new confirmatory statistics method is introduced for the determination of the cortical distributions of electric neuronal activity that generate each microstate. All microstates have common posterior cingulate generators, while three microstates additionally include activity in the left occipital/parietal, right occipital/parietal, and anterior cingulate cortices. This appears to be a fragmented version of the metabolically (PET/fMRI) computed default mode network (DMN), supporting the notion that these four regions activate sequentially at high time resolution, and that slow metabolic imaging corresponds to a low-pass filtered version. In the second part of this study, the microstate amplitude time series are used as the basis for estimating the strength, directionality, and spectral characteristics (i.e., which oscillations are preferentially transmitted) of the connections that are mediated by the microstate transitions. The results show that the posterior cingulate is an important hub, sending alpha and beta oscillatory information to all other microstate generator regions. Interestingly, beyond alpha, beta oscillations are essential in the maintenance of the brain during resting state.Comment: pre-print, technical report, The KEY Institute for Brain-Mind Research (Zurich), Kansai Medical University (Osaka

EEG Microstates During Resting Represent Personality Differences

We investigated the spontaneous brain electric activity of 13 skeptics and 16 believers in paranormal phenomena; they were university students assessed with a self-report scale about paranormal beliefs. 33-channel EEG recordings during no-task resting were processed as sequences of momentary potential distribution maps. Based on the maps at peak times of Global Field Power, the sequences were parsed into segments of quasi-stable potential distribution, the ‘microstates'. The microstates were clustered into four classes of map topographies (A-D). Analysis of the microstate parameters time coverage, occurrence frequency and duration as well as the temporal sequence (syntax) of the microstate classes revealed significant differences: Believers had a higher coverage and occurrence of class B, tended to decreased coverage and occurrence of class C, and showed a predominant sequence of microstate concatenations from A to C to B to A that was reversed in skeptics (A to B to C to A). Microstates of different topographies, putative "atoms of thought”, are hypothesized to represent different types of information processing.The study demonstrates that personality differences can be detected in resting EEG microstate parameters and microstate syntax. Microstate analysis yielded no conclusive evidence for the hypothesized relation between paranormal belief and schizophreni

Salt-dependent regulation of a CNG channel subfamily in Arabidopsis

<p>Abstract</p> <p>Background</p> <p>In <it>Arabidopsis thaliana</it>, the family of cyclic nucleotide-gated channels (CNGCs) is composed of 20 members. Previous studies indicate that plant CNGCs are involved in the control of growth processes and responses to abiotic and biotic stresses. According to their proposed function as cation entry pathways these channels contribute to cellular cation homeostasis, including calcium and sodium, as well as to stress-related signal transduction. Here, we studied the expression patterns and regulation of <it>CNGC19 </it>and <it>CNGC20</it>, which constitute one of the five CNGC subfamilies.</p> <p>Results</p> <p>GUS, GFP and luciferase reporter assays were used to study the expression of <it>CNGC19 </it>and <it>CNGC20 </it>genes from <it>Arabidopsis thaliana </it>in response to developmental cues and salt stress. <it>CNGC19 </it>and <it>CNGC20 </it>were differentially expressed in roots and shoots. The <it>CNGC19 </it>gene was predominantly active in roots already at early growth stages. Major expression was observed in the phloem. <it>CNGC20 </it>showed highest promoter activity in mesophyll cells surrounding the veins. Its expression increased during development and was maximal in mature and senescent leaves. Both genes were upregulated in the shoot in response to elevated NaCl but not mannitol concentrations. While in the root, <it>CNGC19 </it>did not respond to changes in the salt concentration, in the shoot it was strongly upregulated in the observed time frame (6-72 hours). Salt-induction of <it>CNGC20 </it>was also observed in the shoot, starting already one hour after stress treatment. It occurred with similar kinetics, irrespective of whether NaCl was applied to roots of intact plants or to the petiole of detached leaves. No differences in K and Na contents of the shoots were measured in homozygous T-DNA insertion lines for <it>CNGC19 </it>and <it>CNGC20</it>, respectively, which developed a growth phenotype in the presence of up to 75 mM NaCl similar to that of the wild type.</p> <p>Conclusion</p> <p>Together, the results strongly suggest that both channels are involved in the salinity response of different cell types in the shoot. Upon salinity both genes are upregulated within hours. <it>CNGC19 </it>and <it>CNGC20 </it>could assist the plant to cope with toxic effects caused by salt stress, probably by contributing to a re-allocation of sodium within the plant.</p

Inhibition of NOS-NO system prevents autoimmune orchitis development in rats: relevance of no released by testicular macrophages in germ cell apoptosis and testosterone secretion

Background: Although the testis is considered an immunoprivileged organ it can orchestrate immune responses against pathological insults such as infection and trauma. Experimental autoimmune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infiltrate the interstitium concomitantly with progressive germ cell degeneration and impaired steroidogenesis. Up-regulation of nitric oxide (NO)-NO synthase (NOS) system occurs, macrophages being the main producers of NO. Objective: The aim of our study was to evaluate the role of NO-NOS system in orchitis development and determine the involvement of NO released by testicular macrophages on germ cell apoptosis and testosterone secretion. Method and Results: EAO was induced in rats by immunization with testicular homogenate and adjuvants (E group) and a group of untreated normal rats (N) was also studied. Blockage of NOS by i.p. injection of E rats with a competitive inhibitor of NOS, L-NAME (8mg/kg), significantly reduced the incidence and severity of orchitis and lowered testicular nitrite content. L-NAME reduced germ cell apoptosis and restored intratesticular testosterone levels, without variations in serum LH. Co-culture of N testicular fragments with testicular macrophages obtained from EAO rats significantly increased germ cell apoptosis and testosterone secretion, whereas addition of L-NAME lowered both effects and reduced nitrite content. Incubation of testicular fragments from N rats with a NO donor DETA-NOnoate (DETA-NO) induced germ cell apoptosis through external and internal apoptotic pathways, an effect prevented by N-acetyl-L-cysteine (NAC). DETA-NO inhibited testosterone released from Leydig cells, whereas NAC (from 2.5 to 15 mM) did not prevent this effect. Conclusions: We demonstrated that NO-NOS system is involved in the impairment of testicular function in orchitis. NO secreted mainly by testicular macrophages could promote oxidative stress inducing ST damage and interfering in Leydig cell function.Fil: Jarazo Dietrich, Sabrina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Fass, Mónica Irina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Jacobo, Patricia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Sobarzo, Cristian Marcelo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Lustig, Livia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Theas, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina; Argentina. Universidad de Buenos Aires; Argentin

Functionally aberrant electrophysiological cortical connectivities in first episode medication-naive schizophrenics from three psychiatry centers

Functional dissociation between brain processes is widely hypothesized to account for aberrations of thought and emotions in schizophrenic patients. The typically small groups of analyzed schizophrenic patients yielded different neurophysiological findings, probably because small patient groups are likely to comprise different schizophrenia subtypes. We analyzed multichannel eyes- closed resting EEG from three small groups of acutely ill, first episode productive schizophrenic patients before start of medication (from three centers: Bern N = 9; Osaka N = 9; Berlin N = 12) and their controls. Low resolution brain electromagnetic tomography (LORETA) was used to compute intracortical source model-based lagged functional connectivity not biased by volume conduction effects between 19 cortical regions of interest (ROIs). The connectivities were compared between controls and patients of each group. Conjunction analysis determined six aberrant cortical functional connectivities that were the same in the three patient groups. Four of these six concerned the facilitating EEG alpha-1 frequency activity; they were decreased in the patients. Another two of these six connectivities concerned the inhibiting EEG delta frequency activity; they were increased in the patients. The principal orientation of the six aberrant cortical functional connectivities was sagittal; five of them involved both hemispheres. In sum, activity in the posterior brain areas of preprocessing functions and the anterior brain areas of evaluation and behavior control functions were compromised by either decreased coupled activation or increased coupled inhibition, common across schizophrenia subtypes in the three patient groups. These results of the analyzed three independent groups of schizophrenics support the concept of functional dissociation

High-Resolution Genome-Wide Analysis of Irradiated (UV and γ-Rays) Diploid Yeast Cells Reveals a High Frequency of Genomic Loss of Heterozygosity (LOH) Events

In diploid eukaryotes, repair of double-stranded DNA breaks by homologous recombination often leads to loss of heterozygosity (LOH). Most previous studies of mitotic recombination in Saccharomyces cerevisiae have focused on a single chromosome or a single region of one chromosome at which LOH events can be selected. In this study, we used two techniques (single-nucleotide polymorphism microarrays and high-throughput DNA sequencing) to examine genome-wide LOH in a diploid yeast strain at a resolution averaging 1 kb. We examined both selected LOH events on chromosome V and unselected events throughout the genome in untreated cells and in cells treated with either γ-radiation or ultraviolet (UV) radiation. Our analysis shows the following: (1) spontaneous and damage-induced mitotic gene conversion tracts are more than three times larger than meiotic conversion tracts, and conversion tracts associated with crossovers are usually longer and more complex than those unassociated with crossovers; (2) most of the crossovers and conversions reflect the repair of two sister chromatids broken at the same position; and (3) both UV and γ-radiation efficiently induce LOH at doses of radiation that cause no significant loss of viability. Using high-throughput DNA sequencing, we also detected new mutations induced by γ-rays and UV. To our knowledge, our study represents the first high-resolution genome-wide analysis of DNA damage-induced LOH events performed in any eukaryote

Astroculture – Figurations of Cosmology in Media and Arts

Astroculture is a testament to the literary imagination and theoretical innovation of the late Sonja A.J. Neef, who devised the term as an expanding horizon of collaborative research – into the powerful gravitational force exerted on culture by astronomical phenomena and imagery. It is also the name of a conference on the topic inspired by Neef and held at the Center for Advanced Studies Morphomata at the University of Cologne in November, 2011. Indeed, Astroculture is a perfect instance of a morphome, the overall target of the Cologne College’s ongoing symposia: a persistent trope or topos of cultural fascination and transcription appearing across a gamut of civilizations and historical periods. Commentary in this volume ranges from Claudius Ptolemy’s mapping of the universe and the emergence of a pluralistic cosmology in seventeenth-century Europe to the spread of planetariums, the Whole Earth Catalog, and the contemporary artwork of Ingo Günter. With interventions by David Aubin, Lucía Ayala, Monika Bernold, Dietrich Boschung, Bruce Clarke, Gerd Graßhoff, Hans-Christian von Hermann, Martina Leeker, Patricia Pisters, and Henry Sussman

Análisis de equilibrios tautoméricos en β-cetoamidas seleccionadas por espectrometría de masa y RMN : Efectos de solvente, concentración y temperatura. Cálculos teóricos

Las β-cetoamidas constituyen una importante clase de intermediarios bifuncionales para la síntesis de heterociclos, además de ser biológicamente relevantes. Se sintetizaron tres β-cetoamidas y se estudió el equilibrio ceto-enólico y amido-imidol a través del análisis exhaustivo de sus espectros de masa. Se concluye el predominio del equilibrio ceto-enol respecto del amido-imidol. Los espectros de 1HRMN y 13CRMN demuestran la existencia mayoritaria de los tautómeros cetoamido y enolamido, ya que no se aprecian picos característicos para ninguna de las otras formas tautoméricas. Las constantes de equilibrio se calcularon asignando señales características de cada tautómero. Se realizaron determinaciones a diferentes temperaturas y en dos solventes diferentes. Esto permitió poder apreciar la dependencia de la constante de equilibrio con respecto a estas variables. También se calcularon las ΔHT (entalpías de tautomerización) en fase gaseosa y en solución. Los resultados fueron comparados con cálculos teóricos, observándose una buena correlación entre los ellos.Laboratorio de Estudio de Compuestos Orgánico

A High Burden of Asymptomatic Genital Tract Infections Undermines the Syndromic Management Approach Among Adolescents and Young Adults in South Africa: Implications for HIV Prevention Efforts

Background&nbsp; Youth in southern Africa, particularly adolescent girls and young women, are a key population for HIV prevention interventions. Untreated genital tract infections (GTIs) increase both HIV transmission and acquisition risks. South African GTI treatment guidelines employ syndromic management, which relies on individuals to report GTI signs and symptoms. Syndromic management may, however, underestimate cases, particularly among youth. We compared genital tract infection (GTI) prevalence by symptom-based and laboratory assessment among sexually-experienced youth in South Africa, overall and stratified by sex. Methods&nbsp; Interviewer-administered surveys assessed socio-demographics, behaviors, and GTI symptoms among 352 youth (16-24 yrs., HIV-negative or unknown HIV status at enrollment) enrolled in community-based cohorts in Durban and Soweto (2014–2016). Laboratory tests assessed HIV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), Trichomonas vaginalis (TV) infections and, among females, bacterial vaginosis (BV) and Candida species. Youth with genital ulcers were tested for HSV-2 and syphilis. We assessed sensitivity (and specificity) of symptom-based reporting in identifying laboratory-confirmed GTIs. Results&nbsp; At baseline, 16.2% of females (32/198) and&thinsp;&lt;&thinsp;1% (1/154) of males reported ≥1 GTI symptom. However, laboratory tests identified ≥1 GTI in 70.2% and 10.4%, respectively. Female CT prevalence was 18.2%, NG 7.1%, MG 9.6%, TV 8.1%, and 5.1% were newly diagnosed with HIV. BV prevalence was 53.0% and candidiasis 9.6%. One female case of herpes was identified (0 syphilis). Male CT prevalence was 7.8%, NG 1.3%, MG 3.3%, TV &lt;&thinsp;1%, and 2.0% were newly diagnosed with HIV. Overall, 77.8% of females and 100% of males with laboratory-diagnosed GTIs reported no symptoms or were asymptomatic. Sensitivity (and specificity) of symptom-based reporting was 14% (97%) among females and 0% (99%) among males. Conclusion&nbsp; A high prevalence of asymptomatic GTIs and very poor sensitivity of symptom-based reporting undermines the applicability of syndromic GTI management, thus compromising GTI control and HIV prevention efforts among youth. Syndromic GTI management does not meet the sexual health needs of young people. Policy changes incorporating innovations in GTI diagnostic testing are needed to reduce GTIs and HIV-associated risks among youth