Empirisch gestützte Entwicklung von Lerneinheiten zum Umgang mit Multimetern

Im Rahmen der Plattform FLexKom werden an der RWTH Aachen University Unterrichtsmaterialien zum Fördern und Lernen experimenteller Kompetenzen entwickelt. Dabei wurden auch zwei Module konzipiert, die den Umgang mit Multimetern thematisieren. Um einen detaillierten Einblick in die diesbezüglichen Fähigkeiten von Schülerinnen und Schülern und typische Schwierigkeiten bei der Nutzung von Multimetern zu erlangen, wurden umfangreiche Daten aus virtuellen Experimenten zu elektrischen Schaltungen analysiert. Diese Daten stammen aus dem Test zur Messung experimenteller Kompetenz in Large Scale Assessments (MeK-LSA) von H. Theyßen et al., in dem der Aufbau eines Experiments eine von acht getesteten Kompetenzen ist. Mittels 101 Testdatensätzen konnten verschiedene Fehler im Umgang mit Multimetern ausfindig gemacht werden, die gehäuft bei den Schülerinnen und Schülern aufgetreten sind. Diese Ergebnisse bildeten die Grundlage für die Entwicklung von zwei Modulen, in denen separat darauf fokussiert wird, wie Ampere- und Voltmeter in einen elektrischen Schaltkreis integriert bzw. eingestellt werden müssen. Neben den Ergebnissen der Analyse der MeK-LSA-Daten werden auch die konzipierten Module mit ihren Experimentieraufgaben und erste Ergebnisse ihrer Evaluierung vorgestellt

Empirisch gestützte Entwicklung von Lerneinheiten zum Umgang mit Multimetern

Im Rahmen der Plattform FLexKom werden an der RWTH Aachen University Unterrichtsmaterialien zum Fördern und Lernen experimenteller Kompetenzen entwickelt. Dabei wurden auch zwei Module konzipiert, die den Umgang mit Multimetern thematisieren. Um einen detaillierten Einblick in die diesbezüglichen Fähigkeiten von Schülerinnen und Schülern und typische Schwierigkeiten bei der Nutzung von Multimetern zu erlangen, wurden umfangreiche Daten aus virtuellen Experimenten zu elektrischen Schaltungen analysiert. Diese Daten stammen aus dem Test zur Messung experimenteller Kompetenz in Large Scale Assessments (MeK-LSA) von H. Theyßen et al., in dem der Aufbau eines Experiments eine von acht getesteten Kompetenzen ist. Mittels 101 Testdatensätzen konnten verschiedene Fehler im Umgang mit Multimetern ausfindig gemacht werden, die gehäuft bei den Schülerinnen und Schülern aufgetreten sind. Diese Ergebnisse bildeten die Grundlage für die Entwicklung von zwei Modulen, in denen separat darauf fokussiert wird, wie Ampere- und Voltmeter in einen elektrischen Schaltkreis integriert bzw. eingestellt werden müssen. Neben den Ergebnissen der Analyse der MeK-LSA-Daten werden auch die konzipierten Module mit ihren Experimentieraufgaben und erste Ergebnisse ihrer Evaluierung vorgestellt

Sensorimotor pathway controlling stopping behavior during chemotaxis in the Drosophila melanogaster larva.

Sensory navigation results from coordinated transitions between distinct behavioral programs. During chemotaxis in the Drosophila melanogaster larva, the detection of positive odor gradients extends runs while negative gradients promote stops and turns. This algorithm represents a foundation for the control of sensory navigation across phyla. In the present work, we identified an olfactory descending neuron, PDM-DN, which plays a pivotal role in the organization of stops and turns in response to the detection of graded changes in odor concentrations. Artificial activation of this descending neuron induces deterministic stops followed by the initiation of turning maneuvers through head casts. Using electron microscopy, we reconstructed the main pathway that connects the PDM-DN neuron to the peripheral olfactory system and to the pre-motor circuit responsible for the actuation of forward peristalsis. Our results set the stage for a detailed mechanistic analysis of the sensorimotor conversion of graded olfactory inputs into action selection to perform goal-oriented navigation

The structure-function relationships underlying Drosophila larval chemotaxis

The Drosophila larva is an excellent model organism to study the neural correlates of behavior. It possesses a tractable yet complex nervous system that is capable of integrating and transforming multimodal sensory stimuli into complex navigational decisions. In the larva, activity of individual neurons –the building blocks of the nervous system– could be reliably monitored and manipulated thanks to the unmatched genetic tools available in Drosophila. Recent efforts to reconstruct the connectome of the whole larval nervous system enable circuit-level analysis of the neural mechanisms underlying the larval behavior. The larva exhibits robust navigation in the presence of volatile chemical cues (chemotaxis). Larval chemotaxis comprises alternations between different behavioral modes: runs, pauses and turns. Here, we performed two independent forward screens to identify neurons that are involved in action selection during Drosophila larval chemotaxis. In our first screen, we identified neurons that are involved in run-to-turn transitions. High-resolution behavioral analysis upon manipulation of activity in a subset of neurons in the subesophageal zone revealed that these neurons are necessary and sufficient to trigger reorientation maneuvers. Our findings suggest that the SEZ is a premotor center that mediates action selection based on integrated sensory stimuli. In the second screen, we combined functional analysis with electron microscopy reconstruction to identify a descending neuron (PDM) that is necessary and sufficient to trigger run-to-turn transitions. EM reconstruction revealed that PDM receives olfactory inputs in the lateral horn region and connects to premotor neurons involved in peristaltic wave propagation through a set of SEZ descending neurons. By combining optogenetic activation with high-resolution analysis of behavior, we showed that PDM is responsible for terminating runs by inhibiting peristaltic wave-generating circuits in the ventral nerve cord of the larva.La larva de Drosophila es un excelente organismo modelo para estudiar las correlaciones neuronales del comportamiento. Posee un dócil pero complejo sistema nervioso capaz de integrar y transformar estímulos sensoriales multimodales en decisiones de navegación complejas. En la larva, la actividad de neuronas individuales –las piezas fundamentales del sistema nervioso-puede ser controlada y manipulada de manera fiable gracias a las inigualables herramientas genéticas disponibles en Drosophila. Esfuerzos recientes para reconstruir el conectoma completo del sistema nervioso de la larva nos permite analizar el mecanismo neuronal a nivel de circuito subyacente al comportamiento de la larva. La larva presenta una navegación robusta en presencia de señales químicas volátiles (quimiotaxis). La quimiotaxis de la larva alterna entre distintos modos de comportamiento: carreras, pausas y giros. Aquí, hemos llevado a cabo dos cribados independientes que nos permiten identificar neuronas de la larva de Drosophila involucradas en la selección de acciones durante la quiomitaxis. En nuestro primer cribado, hemos identificado neuronas involucradas en transiciones correr-para-girar. El análisis del comportamiento a alta resolución, habiendo manipulado la actividad de un grupo de neuronas de la zona subesofageal (SEZ), reveló que dichas neuronas son necesarias y suficientes para activar maniobras de reorientación. Nuestros descubrimientos sugieren que la SEZ es un centro premotor que media la selección de acciones basándose en estímulos sensoriales integrados. En el segundo cribado, hemos combinado el análisis funcional con la reconstrucción mediante microscopia electrónica para identificar la neurona descendiente (PDM) que es necesaria y suficiente para activar las transiciones correr-para-girar. La reconstrucción mediante EM reveló que la PDM recibe señales olfativas en la región del asta lateral y se conecta con neuronas premotoras involucradas en la propagación de ondas peristálticas a través de un conjunto de neuronas SEZ descendientes. Combinando la activación optogenética con el análisis del comportamiento de alta resolución, hemos demostrado que la PDM es la responsable de terminar carreras inhibiendo los circuitos de generación de ondas peristálticas en el cordón nervioso ventral de la larva

Haemophagocytic Lymphohistiocytosis in a Newborn Infant Presenting with Cholestasis: Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a rare, fatal disease. Neonatal cholestasis exhibits symptoms similar to those seen in several newborn diseases. HLH is rapidly fatal; therefore, an effective and prompt differential diagnosis is vital. A 10-hour-old newborn with icterus was referred to our clinic. Laboratory examination revealed direct bilirubinemia and pancytopenia, and cholestasis developed. HLH findings were observed in the bone marrow aspiration. Induction chemotherapy as described in the HLH-2004 protocol was initiated. Despite notable improvement in clinical signs and laboratory findings, the infant died, probably due to sepsis, one week after start of chemotherapy HLH should be kept in mind in the differential diagnosis of all cholestatic patients with recently developed cytopenia. For definitive diagnosis of HLH, clinical signs and laboratory findings of the patient should be evaluated, hyperferritinemia and hypertriglyceridemia should be searched and bone marrow aspiration materials should be examined carefully

Repeated Courses of Oral Ibuprofen in Premature Infants with Patent Ductus Arteriosus: Efficacy and Safety

BACKGROUND: There are limited data about the results of repeated oral ibuprofen (OIBU) treatment. This study aimed to describe patent ductus arteriosus (PDA) closure rates and adverse events after repeated courses of OIBU in premature infants with PDA. METHODS: Preterm infants with hemodynamically significant (hs)PDA were enrolled in the study. If the first course of OIBU treatment failed, a second and, if required, third course was administered. RESULTS: A total of 100 patients received OIBU. In six patients, treatment could not be completed due to death (n=3) and side effects (n=3). In three patients, adverse effects related to OIBU (thrombocytopenia and impairment of renal function) developed during the first course. During the second and third courses, no new adverse event occurred. After all courses, the PDA closure rate was determined as 88%. The rate was 71% after the first course, 40% after the second course, and 35% after the third course. Although the second course resulted in a significant increase in the closure rate (p0.05). The mean postnatal age at the start of the first dose of OIBU was not significantly different among the responders and non-responders to the first course (p>0.05). Clinical characteristics did not affect the closure rate significantly. The number of courses did not have a significant effect on death, when gestational age and birth weight were used as covariates [p=0.867, Exp(B)=0.901, 95% confidence interval=0.264-3.1]. CONCLUSION: A second course of OIBU seems effective and safe for use in preterm infants with hsPDA. Although a third course of OIBU results in PDA closure in some additional patients, the difference is not significant. Thus, surgical ligation should be considered after the second course, especially in patients with signs of severe heart failure

A CASE OF DILATED CARDIOMYOPATHY DUE TO HYPOCALCEMIA IN NEWBORN

Dilation of one or both ventricles and systolic dysfunction occur dilated cardiomyopathy. Hypocalcemia is a rare cause of reversible heart failure and dilated cardiomyopathy. A seventeen-day old male infant was brought to our clinic with complaints of poor feeding and convulsion. On physical examination, the patient had worse general appearance and was apathetic. Examination of cardiovascular system revealed 2/6 diastolic murmur and signs of congestive heart failure. The value of serum calcium was 4.8 mg / dL. Cerebrospinal fluid examination was unremarkable. Echocardiographic evaluation showed enlarged heart chambers and globally hypokinetic left ventricular wall. Left ventricular ejection fraction was 39% and shortening fraction was 17%. After the treatment of calcium gluconate, a clinically dramatic improvement was observed. On the second day of hospitalization, the echocardiographic examination was normal. Therefore, we suggest that sermon calcium level in newborn with cardiomyopathy should be measured

Prognostic value of amplitude-integrated electroencephalography in neonates with hypernatremic dehydration

Conclusion: The follow-up of newborns after discharge is key to determine the risks associated with hypernatremic dehydration. Our results suggest that hypernatremic dehydration had no impact on the long-term outcome. In addition, continuous aEEG monitoring could provide information regarding early prognosis and mortality

Phototherapy causes a transient DNA damage in jaundiced newborns

In this study, we aimed to clarify the following questions: 1) Does phototherapy (PT) cause genotoxicity in full-term newborn babies undergoing PT as a result of neonatal jaundice?, 2) if genotoxic effect occurs, is there any relationship between the duration of PT and genotoxicity?, and 3) is genotoxic effect temporary or not? The frequency of sister chromatid exchange (SCE) was determined in jaundiced newborns before, during, and after phototherapy, then determined again in childhood (approximately 3.5 years old). Mean frequency of SCE of 22 full-term jaundiced babies significantly increased during the PT procedure and in every single day, compared to the previous day, in comparison to the pre-PT basal value (6.20 +/- 0.57;); mean SCE frequencies at 24, 48, 72, and 96 hours were 7.75 +/- 0.40, 8.16 +/- 0.47, 8.50 +/- 0.40, and 9.36 +/- 0.55, respectively (all P-values < 0.01). In childhood, no significant difference was found between the mean SCE value (4.9 +/- 0.9) of 20 of 22 children, who received PT in the neonatal period, and the mean SCE value (4.7 +/- 0.6) of 20 coevaluated healthy children (P = 0.40). This study demonstrates that the negative effect of PT on SCE is a temporary effect