Differences in physical and mechanical wood properties of mesquite (Prosopis laevigata) in four locations in Northeast Mexico

Mesquite wood (Prosopis laevigata is used for a wide range of purposes, e.g. construction, decoration, and energy. The differences in physical and mechanical wood properties of P. laevigata in four locations, northeast Mexico, were investigated. The results showed that densities at 12% Equilibrium Moisture Content (EMC) in the four sites ranged from 0.79-0.91 g 3/cm compared to 0.72-0.84 g 3/cm under oven dry conditions. Tangential and radial shrinkage varied from 2.2- 3.3% and 1.6-1.9%, respectively. Modulus of rupture (MOR) ranged between 97-114 N 2/mm, static and dynamic modulus of elasticity (MOE(stat), MOE(dyn)) varied from 6,580 and 9,669 N 2/mm and 6,677 to 9,984 N 2/mm, respectively. The correlation between MOE(stat) and MOE(dyn) was 0.94. Physical and mechanical wood properties of P.laevigata varied depending on latitude, growth conditions and forest sites. Physical wood properties should be considered by foresters when selecting tree site or individual trees for plantation programs

Intrinsic up-regulation of 2-AG favors an area specific neuronal survival in different in vitro models of neuronal damage

BACKGROUND: The endocannabinoid 2-arachidonoyl glycerol (2-AG) acts as a retrograde messenger and modulates synaptic signaling e. g. in the hippocampus. 2-AG also exerts neuroprotective effects under pathological situations. To better understand the mechanism beyond physiological signaling we used Organotypic Entorhino-Hippocampal Slice Cultures (OHSC) and investigated the temporal regulation of 2-AG in different cell subsets during excitotoxic lesion and dendritic lesion of long range projections in the enthorhinal cortex (EC), dentate gyrus (DG) and the cornu ammonis region 1 (CA1). RESULTS: 2-AG levels were elevated 24 h after excitotoxic lesion in CA1 and DG (but not EC) and 24 h after perforant pathway transection (PPT) in the DG only. After PPT diacylglycerol lipase alpha (DAGL) protein, the synthesizing enzyme of 2-AG was decreased when Dagl mRNA expression and 2-AG levels were enhanced. In contrast to DAGL, the 2-AG hydrolyzing enzyme monoacylglycerol lipase (MAGL) showed no alterations in total protein and mRNA expression after PPT in OHSC. MAGL immunoreaction underwent a redistribution after PPT and excitotoxic lesion since MAGL IR disappeared in astrocytes of lesioned OHSC. DAGL and MAGL immunoreactions were not detectable in microglia at all investigated time points. Thus, induction of the neuroprotective endocannabinoid 2-AG might be generally accomplished by down-regulation of MAGL in astrocytes after neuronal lesions. CONCLUSION: Increase in 2-AG levels during secondary neuronal damage reflects a general neuroprotective mechanism since it occurred independently in both different lesion models. This intrinsic up-regulation of 2-AG is synergistically controlled by DAGL and MAGL in neurons and astrocytes and thus represents a protective system for neurons that is involved in dendritic reorganisation

Hot water extraction of Norway spruce (Picea abies [Karst.]) bark: analyses of the influence of bark aging and process parameters on the extract composition.

The hot water (HW) extraction of Norway spruce (Picea abies [Karst.]) delivers condensed tannins and considerable amounts of other compounds. Yield and composition of the HW extracts were investigated as a function of natural weathering for up to 15 months. Total phenol monomers and oligomers were detected by Folin-Ciocaltau assay after fractionation by solid phase extraction (SPE). Procyanidins (PC) were determined by HPLC-UV after acid thiolysis and carbohydrates by HPLC combined with acid hydrolysis. Topochemistry of the bark before and after extraction was investigated by UV- microspectrometry (UMSP) and non-extractable PC analyzed by direct thiolysis on the bark. The influence of the parameters on the yield and composition of the extracts were evaluated, such as the extraction temperature, time and the addition of sodium sulfate and urea. Prolonged weathering resulted in a considerable decrease of the total extraction yield, partly because of leaching of phenolic monomers, mono- and oligosaccharides. The yield of phenolic oligomers also decreased at a moderate rate, while the yield of polysaccharides (pectins) was almost stable. Nonextractable and non-leachable compounds deposited in the cell lumens represent the majority of the phenolic extractives in spruce bark. Sequential extractions performed at increasing temperature proved to be a suitable method for the recovery of tannin-rich extracts

A reference dataset for verifying numerical electrophysiological heart models

<p>Abstract</p> <p>Background</p> <p>The evaluation, verification and comparison of different numerical heart models are difficult without a commonly available database that could be utilized as a reference. Our aim was to compile an exemplary dataset.</p> <p>Methods</p> <p>The following methods were employed: Magnetic Resonance Imaging (MRI) of heart and torso, Body Surface Potential Maps (BSPM) and MagnetoCardioGraphy (MCG) maps. The latter were recorded simultaneously from the same individuals a few hours after the MRI sessions.</p> <p>Results</p> <p>A training dataset is made publicly available; datasets for blind testing will remain undisclosed.</p> <p>Conclusions</p> <p>While the MRI data may provide a common input that can be applied to different numerical heart models, the verification and comparison of different models can be performed by comparing the measured biosignals with forward calculated signals from the models.</p

IT Mission: Interdisziplinäre Online Expeditionen

Das Schülerlabor "IT Mission" verbindet Themen der Informatik, Naturwissenschaft und Technik. In interdisziplinären Expeditionen können Schüler*innen erfahren, wie Technologie helfen kann, große Ziele wie z.B. die Rettung der Bienen zu verfolgen. Dabei erforschen sie MINT- und Biologiephänomene und wie Informatik dabei helfen kann, diese zu verstehen und neues Wissen zu erschaffen. Sie erleben die Freude an Expeditionen ins Unbekannte, rüsten sich mit MINT-Arbeitsmethoden und -Werkzeugen aus und wenden sie zur Lösung ihrer Problemstellungen an. Mithilfe der Expeditionen können die SchülerInnen naturwissenschaftliche Arbeitsweisen erleben und forschendes Lernen selbst erfahren. In insgesamt sechs Expeditionen lernen sie u.a. Grundlagen der Webentwicklung kennen und wie sie als Data Scientist neues Wissen in großen Datenmengen entdecken, um so den Bienen bei der Nahrungssuche zu helfen, oder wie ihnen künstliche Intelligenz dabei helfen kann, das Verhalten der Bienen besser zu verstehen

Klimaschutz und Verkehr: Zielerreichung nur mit unbequemen Maßnahmen möglich. Ariadne-Analyse.

n der Ariadne-Analyse befassen sich die Autoren mit Maßnahmen, die klimaschützendes Verhalten belohnen (z.B. durch Ausbau der Infrastruktur des Nahverkehrs) und klimaschädigendes Verhalten einschränken (z.B. Flugverkehrssteuer). Die Forschenden betrachten dabei einerseits die jeweiligen Effekte auf die Minderungen von Treibhausgasemissionen und andererseits die Einstellung der Bevölkerung zu den Maßnahmen. Sie stellen fest, dass die Maßnahmen, die den Individualverkehr einschränken, das höchste CO2-Einsparpotential haben, wie beispielsweise die Erhöhung der Benzinpreise und die Einführung einer Maut. In der Bevölkerung stehen dagegen der Ausbau des Nah- und Radverkehrs an erster Stellen, um verkehrsbedingte Emissionen zu senken. Maßnahmen, die eine höhere individuelle finanzielle Belastung bei der Nutzung von Verkehrsmitteln zur Folge hat, werden dagegen oft mehrheitlich abgelehnt. Die Forschenden geben auch einen ersten Ausblick, wie die Diskrepanz zwischen effektiven Maßnahmen und ihrer Akzeptanz in der Bevölkerung aufgehoben werden kann. Sie diskutieren zum Beispiel das Thema Rückerstattung und eine zielgruppengerechte Kommunikation zwischen Politik und Gesellschaft