756 research outputs found
When size matters: how the layout of primary visual cortex (V1) shapes higher cognitive functioning
Human beings are endowed with a wide range of highly developed cognitive abilities. Which factors have led to this level of intellectual capacity in the course of evo- lution?
In cross species studies, overall brain size is a reliable predictor of cognitive performance, but more specific information about how the brainâs structural and functional organization may be linked to these enhancements is lacking. The aim of this thesis was to investigate the role of the anatomy and function of the primary visual cortex (V1) in behaviour. V1 is the earliest sensory stage for vision in the cerebral cortex, and is responsible for processing low-level visual features such as spatial orientation, location and frequency. Interestingly, V1 size displays huge variance between individuals; this offers an amazing opportunity to study the behavioural effect of brain enlargement within a human sample while avoiding the various confounds that can distort the results in cross species studies.
Previous research has shown that a larger V1 is linked to higher perceptual sensitivity; but to what extent these size differences may also affect higher cognitive functions is unknown. Using a combined approach of behavioural testing and fMRI brain imaging methods, we find that the acuity of two cognitive functions, namely the precision of visual imagery and visual working memory storage, are significantly positively correlated with the surface size of V1: individuals with a larger V1 tended to have more precise imagery and greater visual working memory storage. In contrast, the strength of visual imagery was negatively related to V1 surface size.
In addition, we find that other indices of neural function, such as the concentration of the inhibitory neurotransmitter GABA in the medial occipital cortex and V1 spontaneous functional activity levels, covaried significantly with differences in V1 surface size.
Our findings support the notion of a positive relationship between brain (areal) size and cognition and show how even very low-level sensory areas are involved in shaping our intellect. As a last point, we discuss the potential limitations of the positive link between brain size and cognitive ability
Direct assessment of individual skin barrier components by electrical impedance spectroscopy
Background: Expression of the tight junction proteins Cldn1 and 4 is altered in skin diseases such as atopic dermatitis, and Cldn1 deficiency affects skin barrier formation. Impedance spectroscopy (IS) has been proven to allow detection of alterations in the skin barrier but is currently unable to separate effects on viable epidermis (VE) and stratum corneum (SC).
Methods: Effects of siRNA-mediated Cldn1 and 4 knockdown in reconstructed human epidermis (RHE) on VE and SC barrier function were investigated with Ussing chamber-based IS. Barrier components were sequentially altered, employing iron oxide nanoparticles and EGTA, to identify their contribution to the impedance spectrum. Resistance changes due to apically applied hyperosmolar electrolyte were used to identify barrier defects non-invasively.
Results: IS of RHE yielded two relaxation frequencies, representing the barrier properties of the SC (similar to 1000 Hz) and VE (similar to 100 Hz). As proof of concept, it was shown that the Cldn1 knockdown-induced resistance drop arises from the impairment of both SC and VE, indicated by a shift of both relaxation frequencies. Hyperosmolar electrolyte penetration allowed non-invasive detection of Cldn1 knockdown via time-dependent frequency shifts. The absence of Cldn4 knockdown-induced changes revealed the weaknesses of transepithelial electrical resistance analysis.
Conclusion: In conclusion, the present technique allows to separately measure the barrier properties of SC and VE and further evaluate the Cldn1 and 4 knockdown impact on the skin barrier. As the measurement with agarose-embedded electrolyte allowed non-invasive identification of the Cldn1 knockdown, this opens the way to detailed in vivo skin barrier assessment
Cortical depth profiles in primary visual cortex for illusory and imaginary experiences
Visual illusions and mental imagery are non-physical sensory experiences that involve cortical feedback processing in the primary visual cortex. Using laminar functional magnetic resonance imaging (fMRI) in two studies, we investigate if information about these internal experiences is visible in the activation patterns of different layers of primary visual cortex (V1). We find that imagery content is decodable mainly from deep layers of V1, whereas seemingly ârealâ illusory content is decodable mainly from superficial layers. Furthermore, illusory content shares information with perceptual content, whilst imagery content does not generalise to illusory or perceptual information. Together, our results suggest that illusions and imagery, which differ immensely in their subjective experiences, also involve partially distinct early visual microcircuits. However, overlapping microcircuit recruitment might emerge based on the nuanced nature of subjective conscious experience
Validation of the German version of the Southampton mindfulness questionnaire (SMQ)
Objectives: The aim of the study was to assess the convergent and divergent validity, reliability, utility, and treatment sensitivity of a newly translated German version of the Southampton Mindfulness Questionnaire (SMQ). The SMQ is a 16-item instrument measuring mindful awareness of distressing thoughts, images, and perceptions, developed originally within the mindfulness for psychosis field.
Methods: Overall, three studies were conducted, comprising (1) a non-clinical sample of nâ=â848 (638 community sample and 210 meditators); (2) a clinical sample of nâ=â213 (106 schizophrenia and 107 depression); and (3) a clinical sample with nâ=â122 participants with emotional disorders within a randomized controlled study, of which 30 participants were also included in study 2. To assess convergent validity, participants completed the SMQ, Freiburg Mindfulness Inventory (FMI), and Comprehensive Inventory of Mindfulness Experiences (CHIME). To measure divergent validity, participants completed the Brief Symptom Inventory 18 (BSI-18), Positive and Negative Affect Schedule (PANAS), Brief Experiential Avoidance Questionnaires (BEAQ), and Anxiety Sensitivity Index 3 (ASI-3).
Results: Mean internal consistency (αâ=â0.89) and convergent (râ=â0.66 to 0.73) and divergent validity (râ=âââ0.09 to ââ0.50) were established and sensitivity to change over time following treatment (dâ=â0.86) was shown. For the clinical sample, a single-factor structure is suggested by principal component analysis.
Conclusions: Results provide first evidence for the utility of the German version of the SMQ for clinical practice and research in healthy individuals, meditators, and clinical groups. Further research is needed to examine the underlying construct of mindfulness
E-Learning-Modul "Planung experimenteller Untersuchungen": Entwicklung und Wirkungskontrolle
LangjĂ€hrige Erfahrungen und PrĂŒfungsergebnisse zeigen, dass die Aneignung und die Anwendung methodischen Wissens zur Versuchsplanung von vielen Studierenden der Psychologie als sehr schwierig erlebt werden. Die Anwendung von E-Learning-Komponenten kann als ErgĂ€nzung zu den klassischen Formen der Wissensvermittlung (Vorlesungen, Seminare) einen Beitrag dazu leisten, sowohl die Akzeptanz der als schwierig empfundenen Lerninhalte zu erhöhen als auch das Wissen und die FĂ€higkeiten zu verbessern. Vor diesem Hintergrund wurde in den Jahren 2008 und 2009 an der TU Dresden ein E-Learning-Modul zur experimentellen Versuchsplanung entwickelt, welches die Studierenden dazu befĂ€higen soll, methodisches Wissen zu vertiefen und auf praktische Aufgabenstellungen anzuwenden. In dem Modul wurde zum ersten Mal die Möglichkeit geschaffen, VersuchsplĂ€ne in einem E-Learning-Modul selbststĂ€ndig zu erstellen. Das Modul wurde an Studierenden der Fachrichtung Psychologie erprobt und in einem Zwei-Gruppen-Randomisierungsdesign evaluiert und optimiert. Die Akzeptanz des Moduls ist sehr hoch und lĂ€sst positive Effekte auf die Motivation der Studierenden erwarten. Zudem konnte ein hoch signifikanter Leistungszuwachs in der Versuchsgruppe festgestellt werden.
10.05.2011 | Malgorzata Gorniak, Johanna Petzoldt, Kristina SchÀfer, Nele Wessels, Matthias Rudolf & BÀrbel Bergmann (Dresden
Clinical value of preâdischarge bioâadrenomedullin as a marker of residual congestion and high risk of heart failure hospital readmission
Aims:
Recently, bioâadrenomedullin (bioâADM) was proposed as a congestion marker in heart failure (HF). In the present study, we aimed to study whether bioâADM levels at discharge from a hospital admission for worsening HF could provide additional information on (residual) congestion status, diuretic dose titration and clinical outcomes.
Methods and results:
Plasma bioâADM was measured in 1236 acute HF patients in the PROTECT trial at day 7 or discharge. Median discharge bioâADM was 33.7 [21.5â61.5] pg/mL. Patients with higher discharge bioâADM levels were hospitalised longer, had higher brain natriuretic peptide levels, and poorer diuretic response (all Pâ<â0.001). BioâADM was the strongest predictor of discharge residual congestion (clinical congestion scoreâ>â3) (odds ratio 4.35, 95% confidence interval 3.37â5.62; Pâ<â0.001). Oedema at discharge was one of the strongest predictors of discharge bioâADM (ÎČ = 0.218; Pâ<â0.001). Higher discharge loop diuretic doses were associated with a poorer diuretic response during hospitalisation (ÎČ = 0.187; Pâ<â0.001) and higher bioâADM levels (ÎČ = 0.084; P = 0.020). High discharge bioâADM levels combined with higher use of loop diuretics were independently associated with a greater risk of 60âday HF rehospitalisation (hazard ratio 4.02, 95% confidence interval 2.23â7.26; Pâ<â0.001).
Conclusion:
In hospitalised HF patients, elevated preâdischarge bioâADM levels were associated with higher discharge loop diuretic doses and reflected residual congestion. Patients with combined higher bioâADM levels and higher loop diuretic use at discharge had an increased risk of rehospitalisation. Assessment of discharge bioâADM levels may be a readily applicable marker to identify patients with residual congestion at higher risk of early hospital readmission
20 Jahre nach dem Fall der Mauer: Wie hat sich die Gesundheit in Deutschland entwickelt?
Der vorliegende Bericht gibt einen Ăberblick ĂŒber 20 Jahre »Gesundheitsgeschichte« der Bundesrepublik Deutschland. Dazu wurden Gemeinsamkeiten und Unterschiede zwischen den neuen und alten BundeslĂ€ndern seit der Wiedervereinigung anhand vorliegender Gesundheitsdaten reflektiert. WĂ€hrend sich noch zu Beginn der 1990er-Jahre erhebliche Unterschiede in der gesundheitlichen Situation der Bevölkerung in Ost- und Westdeutschland feststellen lieĂen, hat mittlerweile eine weitgehende AnnĂ€hrung, in einigen Bereichen sogar ein Ausgleich stattgefunden. Noch vorhandene regionale Unterschiede haben zumeist soziale GrĂŒnde: Die Gesundheitschancen sind dort am geringsten, wo die Lebensbedingungen am schlechtesten sind, z.B. in Regionen mit hoher Armutsrisiko- und Arbeitslosenquote
Human placental proteomics and exon variant studies link AAT/SERPINA1 with spontaneous preterm birth
Background: Preterm birth is defined as live birth before 37 completed weeks of pregnancy, and it is a major problem worldwide. The molecular mechanisms that lead to onset of spontaneous preterm birth are incompletely understood. Prediction and evaluation of the risk of preterm birth is challenging as there is a lack of accurate biomarkers. In this study, our aim was to identify placental proteins that associate with spontaneous preterm birth. Methods: We analyzed the proteomes from placentas to identify proteins that associate with both gestational age and spontaneous labor. Next, rare and potentially damaging gene variants of the identified protein candidates were sought for from our whole exome sequencing data. Further experiments we performed on placental samples and placenta-associated cells to explore the location and function of the spontaneous preterm labor-associated proteins in placentas. Results: Exome sequencing data revealed rare damaging variants in SERPINA1 in families with recurrent spontaneous preterm deliveries. Protein and mRNA levels of alpha-1 antitrypsin/SERPINA1 from the maternal side of the placenta were downregulated in spontaneous preterm births. Alpha-1 antitrypsin was expressed by villous trophoblasts in the placenta, and immunoelectron microscopy showed localization in decidual fibrinoid deposits in association with specific extracellular proteins. siRNA knockdown in trophoblast-derived HTR8/SVneo cells revealed that SERPINA1 had a marked effect on regulation of the actin cytoskeleton pathway, SlitâRobo signaling, and extracellular matrix organization. Conclusions: Alpha-1 antitrypsin is a protease inhibitor. We propose that loss of the protease inhibition effects of alpha-1 antitrypsin renders structures critical to maintaining pregnancy susceptible to proteases and inflammatory activation. This may lead to spontaneous premature birth.publishedVersionPeer reviewe
New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.
Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
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