Der metasomale Lichtsinn des Skorpions : eine immunhistologische und feinstrukturelle Untersuchung

Extraretinale Photorezeption im Bauchmark des Skorpions war seit mehr als 30 Jahren aus elektrophysiologischen und verhaltensbiologischen Untersuchungen bekannt. Von den zugehörigen Sinneszellen waren aber weder ihre Struktur und Lage noch ihre neuronale Verschaltung bekannt. Mit immunhistologischen und feinstrukturellen Untersuchungen konnten in dieser Arbeit in den letzten Abdominalganglien des Skorpions Paruroctonus mesaensis Zellgruppen identifiziert werden, die vermutlich das strukturelle Korrelat dieser extraretinalen Photorezeption, des metasomalen Lichtsinns (ML), sind. In meiner Arbeit konnten folgende Befunde erhoben werden: Immunhistologische Erkenntnisse: - In den metasomalen Ganglien des Skorpions gibt es wenige Zellen, die immunhistologisch mit Antikörpern gegen Proteine der Phototransduktionskaskade (Opsin, Transducin und Arrestin) reagieren. - Der metasomale Lichtsinn ist kein geschlossenes Sinnesorgan sondern ist aus mehreren Zellclustern mit jeweils etwa 5-7 spindelförmigen kleinen Zellen zusammengesetzt. - Diese ML-Zellgruppen sind bilateralsymmetrisch auf der Ventralseite der Ganglien jeweils an den Übergängen in die Konnektive angeordnet. - Die Zellen sind - wie alle Invertebraten-Photorezeptoren - histaminerg. Ihre kurzen afferenten Axone enden ipsilateral im gleichen Ganglion auf ebenfalls histaminergen Inteneuronen, die bis in das Unterschlundganglion reichen. Feinstrukturelle Erkenntnisse: - Nach den bisherigen Untersuchungen haben alle ML-Zellen die gleiche Feinstruktur. Das Cytoplasma ist sehr reichhaltig mit Mitochondrien und rauhem endoplasmatischen Retikulum gefüllt, was erkennen lässt, dass diese Zellen hochaktiv sind. Sie haben kein Schirmpigment. - Sie besitzen einen länglichen, häufig gelappten Zellkern mit viel Heterochromatin. - Besonders charakteristisch für die ML-Zellen sind Lysosomen, die rhabdomere Abbauprodukte beinhalten. Diese Abbauprodukte verändern sich in Abhängigkeit vom Licht und unter der Kontrolle der inneren Uhr. Es lassen sich die für Arthropodenaugen charakteristischen Abbaustufen für diese exogenen und endogenen Abbauvorgänge feststellen. - An der apikalen Seite der potentiellen Photorezeptorzellen befinden sich lange rhabdomere Mikrovilli, die sich unregelmäßig um eine Lakune winden. Gemeinsam mit Nachbarzellen bilden diese Mikrovilli eine Haube, die von einer Kapsel umschlossen wird. - Das andere Zellende setzt sich in ein kurzes Axon fort. - Efferente Fasern innervieren die afferenten Endigungen der Rezeptorzellen nahe an ihren Terminalen. - Als Besonderheit ist in den ML-Zellen eine einzelne intrazelluläre Cilie zu finden. Sie ist meist zwischen dem Zellkern und einem Golgi-Apparat lokalisiert. Eine potentielle Funktion des Metasomalen Lichtsinns im Skorpion wird insbesondere im Zusammenhang mit der Perzeption natürlicher Zeitgeberreize durch den retinalen und extraretinalen Photorezeptorkomplex

Playful training of numerical skills in kindergarten for prevention of mathematical disability

In der vorliegenden Evaluationsstudie wurde untersucht, ob numerische Kompetenzen im Vorschulalter durch in den Kindergartenalltag integrierte zahlen- und mengenbezogene Spiele gefördert werden können. Darüber hinaus war es von Interesse herauszufinden, ob Kindergartenkinder mit weniger gut entwickelten numerischen Kompetenzen insofern von dieser Fördermethode profitieren, als dass sie ihren Leistungsrückstand aufholen können. Realisiert wurde ein Prätest-Posttest-Design mit einer Fördergruppe, einer Kontrollgruppe mit Kontrollintervention sowie einer Wartekontrollgruppe. Insgesamt nahmen 142 Kinder im Alter von vier bis fünf Jahren an der Studie teil. Die Ergebnisse kovarianzanalytischer Verfahren mit Messwiederholung sprechen dafür, dass sich die numerischen Kompetenzen von Kindergartenkindern anhand des verwendeten Förderkonzepts steigern lassen. Außerdem konnte gezeigt werden, dass jene Kinder der Fördergruppe, deren numerische Leistung zum Prätestzeitpunkt unter dem Median der Gesamtstichprobe lag, einen höheren Leistungszuwachs aufwiesen als die leistungsstärkeren Kinder, die nicht mit den zahl- und mengenbezogenen Spielen gefördert wurden. Die Ergebnisse weisen somit auch auf eine Eignung des spielerischen Förderkonzepts zur Kompensation von Entwicklungsnachteilen bezüglich der numerischen Kompetenz hin. (DIPF/Orig.)In this study, we investigated if preschool children´s numerical skills can be fostered by playing number- and quantity-related games during children´s daily playtimes. Furthermore, we wanted to find out if preschoolers with poorly developed numerical skills catch up on their developmental delay by playing these games. In order to do so, we used a pretest-posttest-design with (a) an intervention group playing number- and quantity-related games, (b) a control group participating in another intervention with the same basic conditions but other intervention goals and (c) a control group without an intervention. One hundred forty-two children aged 4 to 5 years participated in the study. The results show that preschoolers’ numerical skills can be increased by playing number- and quantity-related games. Furthermore, the numerical skills of children with poorly developed numerical skills increased more significantly than the numerical skills of children with better developed numerical skills who did not play the number- and quantity-related games. Thus, results indicate that playing these number- and quantity-related games might be used to compensate for early developmental disadvantage in numerical skills. (DIPF/Orig.

Development of working memory from grade 3 to 5. Differences between children with and without mathematical learning difficulties

Based on the finding that children with mathematical learning difficulties (MLD) have deficits in working memory (WM), the question arises as to whether these children differ from typical learners only in the level or also in the developmental trajectories of WM functioning. To this end, the WM of 80 children with MLD and 71 typical learners was assessed longitudinally from third to fifth grade. Typical learners outperformed children with MLD in the phonological, visuospatial and central executive WM functioning in third grade. Latent change analyses indicated that both phonological and central executive WM functioning developed in a parallel pattern in children with MLD and in typical learners. In contrast, visuospatial WM functioning revealed a different development in children with and without MLD since the gap between both groups decreased over time. Overall, despite starting at a lower level, the WM functioning in children with MLD did not develop more slowly. (DIPF/Orig.

Hochbegabung und soziale Ungleichheit in der frühen Kindheit

Gegenstand der Publikation ist das Verhältnis von Hochbegabung und sozialer Ungleichheit in der frühen Kindheit. Dabei wird der Fokus auf die pädagogische Arbeit in Kindertageseinrichtungen gelegt. Zunächst wird der Begriff der Hochbegabung als hohe intellektuelle Begabung erschlossen, anschließend im Kontext von Inklusion die Bedeutung der Kindertageseinrichtungen für die Entwicklung hoher kognitiver Begabungen herausgestellt und schließlich mehrdimensional das Verhältnis von Hochbegabung und sozialer Ungleichheit betrachtet. Aus den Erkenntnissen werden Handlungsempfehlungen abgeleitet. (DIPF/Orig.

Genetic Association for Renal Traits among Participants of African Ancestry Reveals New Loci for Renal Function

Chronic kidney disease (CKD) is an increasing global public health concern, particularly among populations of African ancestry. We performed an interrogation of known renal loci, genome-wide association (GWA), and IBC candidate-gene SNP association analyses in African Americans from the CARe Renal Consortium. In up to 8,110 participants, we performed meta-analyses of GWA and IBC array data for estimated glomerular filtration rate (eGFR), CKD (eGFR <60 mL/min/1.73 m2), urinary albumin-to-creatinine ratio (UACR), and microalbuminuria (UACR >30 mg/g) and interrogated the 250 kb flanking region around 24 SNPs previously identified in European Ancestry renal GWAS analyses. Findings were replicated in up to 4,358 African Americans. To assess function, individually identified genes were knocked down in zebrafish embryos by morpholino antisense oligonucleotides. Expression of kidney-specific genes was assessed by in situ hybridization, and glomerular filtration was evaluated by dextran clearance. Overall, 23 of 24 previously identified SNPs had direction-consistent associations with eGFR in African Americans, 2 of which achieved nominal significance (UMOD, PIP5K1B). Interrogation of the flanking regions uncovered 24 new index SNPs in African Americans, 12 of which were replicated (UMOD, ANXA9, GCKR, TFDP2, DAB2, VEGFA, ATXN2, GATM, SLC22A2, TMEM60, SLC6A13, and BCAS3). In addition, we identified 3 suggestive loci at DOK6 (p-value = 5.3×10−7) and FNDC1 (p-value = 3.0×10−7) for UACR, and KCNQ1 with eGFR (p = 3.6×10−6). Morpholino knockdown of kcnq1 in the zebrafish resulted in abnormal kidney development and filtration capacity. We identified several SNPs in association with eGFR in African Ancestry individuals, as well as 3 suggestive loci for UACR and eGFR. Functional genetic studies support a role for kcnq1 in glomerular development in zebrafish

Genes in the Ureteric Budding Pathway: Association Study on Vesico-Ureteral Reflux Patients

Vesico-ureteral reflux (VUR) is the retrograde passage of urine from the bladder to the urinary tract and causes 8.5% of end-stage renal disease in children. It is a complex genetic developmental disorder, in which ectopic embryonal ureteric budding is implicated in the pathogenesis. VUR is part of the spectrum of Congenital Anomalies of the Kidney and Urinary Tract (CAKUT). We performed an extensive association study for primary VUR using a two-stage, case-control design, investigating 44 candidate genes in the ureteric budding pathway in 409 Dutch VUR patients. The 44 genes were selected from the literature and a set of 567 single nucleotide polymorphisms (SNPs) capturing their genetic variation was genotyped in 207 cases and 554 controls. The 14 SNPs with p<0.005 were included in a follow-up study in 202 cases and 892 controls. Of the total cohort, ∼50% showed a clear-cut primary VUR phenotype and ∼25% had both a duplex collecting system and VUR. We also looked for association in these two extreme phenotype groups. None of the SNPs reached a significant p-value. Common genetic variants in four genes (GREM1, EYA1, ROBO2 and UPK3A) show a trend towards association with the development of primary VUR (GREM1, EYA1, ROBO2) or duplex collecting system (EYA1 and UPK3A). SNPs in three genes (TGFB1, GNB3 and VEGFA) have been shown to be associated with VUR in other populations. Only the result of rs1800469 in TGFB1 hinted at association in our study. This is the first extensive study of common variants in the genes of the ureteric budding pathway and the genetic susceptibility to primary VUR

Differential analyses of working memory functioning in children with learning disabilities

Das Ziel dieser Arbeit bestand in der differenziellen Analyse der Funktionstüchtigkeit des Arbeitsgedächtnisses (Baddeley, 1986) bei Kindern mit verschiedenen Lernstörungen. Hierzu wurden Kinder mit Lese-Rechtschreibstörung, Rechenstörung, Kombinierter Störung schulischer Fertigkeiten und Lernbehinderung anhand einer sehr umfangreichen Arbeitsgedächtnisbatterie mit vielen verschiedenen Indikatoren zu den drei Subsystemen phonologische Schleife, visuell-räumlicher Notizblock und zentrale Exekutive untersucht. Es wurde nachgewiesen, dass Kinder mit und ohne Lernstörung über eine identische dreigliedrige Struktur des Arbeitsgedächtnisses verfügen. Weiterhin konnten für verschiedene Störungsbilder spezifische und voneinander abgrenzbare Defizitmuster im Arbeitsgedächtnis aufgedeckt werden. So zeigten sich phonologische Arbeitsgedächtnisdefizite bei Störungen im Lesen und Schreiben, visuell-räumliche Arbeitsgedächtnisdefizite bei Störungen im Rechnen und phonologische, visuell-räumliche und zentral exekutive Arbeitsgedächtnisdefizite bei umfassenden Schulleistungsstörungen (kombinierte Störung schulischer Fertigkeiten und Lernbehinderung). Eine weiterführende Analyse zeigte auf, dass sich Kinder mit kombinierter Schulleistungsstörung und Lernbehinderung nicht in ihren Arbeitsgedächtnisleistungen unterscheiden

Working memory in children with learning disabilities in reading versus spelling. Searching for overlapping and specific cognitive factors

In transparent orthographies like German, isolated learning disabilities in either reading or spelling are common and occur as often as a combined reading and spelling disability. However, most issues surrounding the cognitive causes of these isolated or combined literacy difficulties are yet unresolved. Recently, working memory dysfunctions have been demonstrated to be promising in explaining the emergence of literacy difficulties. Thus, we applied a 2 (reading disability: yes vs. no) × 2 (spelling disability: yes vs. no) factorial design to examine distinct and overlapping working memory profiles associated with learning disabilities in reading versus spelling. Working memory was assessed in 204 third graders, and multivariate analyses of variance were conducted for each working memory component. Children with spelling disability suffered from more pronounced phonological loop impairments than those with reading disability. In contrast, domain-general central-executive dysfunctions were solely associated with reading disability, but not with spelling disability. Concerning the visuospatial sketchpad, no impairments were found. In sum, children with reading disability and those with spelling disability seem to be characterized by different working memory profiles. Thus, it is important to take both reading and spelling into account when investigating cognitive factors of literacy difficulties in transparent orthographies

Phonological processing in children with specific reading disorder versus typical learners. Factor structure and measurement invariance in a transparent orthography

Although children with specific reading disorder (RD) have often been comparen to typically achieving children on various phonological processing tasks, to our knowledge no study so far has examined whether the structure of phonological processing applies to both groups of children alike. According to Wagner and Torgesen (1987), phonological processing consists of 3 distinct constructs: phonological awareness (PA), rapid automatized naming (RAN), and the phonological loop (PL) of working memory. The present study examined whether this phonological processing model which was originally developed for English orthography is also applicable to a more transparent language such as German. Furthermore, we tested whether the structure of phonological processing is invariant across typically achieving children and children with RD. Therefore, 209 German-speaking 3rd graders (100 typical learners and 109 children with RD) completed a comprehensive test battery assessing PA, RAN, and PL. Using confirmatory factor analyses, we compared the latent structure of these phonological processing skills across both groups. The study yielded 3 important findings: First, Wagner and Torgesen\u27s (1987) model transfers to the German language and its orthography with transparent grapheme-to-phoneme correspondences. Second, the tripartite structure of phonological processing was evident across both groups (factorial invariance). Third, group invariance was also found for the measurement and structural components of the model (measurement invariance). These findings suggest that the nature of phonological processing is invariant across typically achieving children and children with RD acquiring the transparent orthography of German. Theoretical and practical implications are discussed. (DIPF/Orig.

Training Working Memory of Children with and without Dyslexia

For the future school performance of a child in the fields of literacy and numeracy, the operational efficiency of working memory is a central predictor. Children affected by dyslexia exhibit specific deficits in the functions of working memory. A software application for elementary school-age children has been specifically developed for this study, attempting to improve the working memory&#8217;s operational efficiency. Based on Baddeley&#8217;s model of working memory (1986), the phonological loop, the visuo-spatial sketchpad, and the central executive were trained in 18 sessions over a period of six weeks. The group of test subjects undergoing this training was composed of third-graders, of which 43 were and 27 were not affected by dyslexia. The untrained control group was made up of 41 third-graders with dyslexia and 28 without dyslexia. While the short-term effects of the program could not be proven, the present analyses focus on long-term effects. The results obtained from a pre-test/follow-up design reveal that no long-term increases in performance regarding phonological and central executive working memory could be confirmed. Only the visuo-spatial Corsi block span exhibited a training effect over a period of three months. Additionally, training did not show any long-term effect of performance improvement, not even for a subgroup of children with dyslexia and an especially low working memory performance. Thus, even after this study, the question whether working memory can be trained or not remains partly unanswered but leaves us predominantly pessimistic