Externe Validität ökologischer Experimente einschätzen können. Befunde und Überlegungen zur Messung und Förderung

Lebende Systeme angemessen zu verstehen, setzt Wissen über Ursache-Wirkungsbeziehungen zwischen deren Elementen und mit deren Umgebung voraus. Entsprechende Erkenntnisse zu gewinnen, erfordert Kompetenzen für die eigenständige Planung, Durchführung und Auswertung von Experimenten sowie deren kritische Beurteilung. In der Ökologie sind angesichts der Systemkomplexität in besonderem Maß auch Überlegungen zur Tragweite experimenteller Befunde nötig. Zur Erfassung eines niederschwelligen Verständnisses für zwei Aspekte der externen Validität wurde ein schriftliches Testinstrument entwickelt und validiert sowie die dimensionale Struktur des Konstrukts analysiert. Lernende der 6. (n = 79) und der 9. Klassenstufe (n = 50) (Gymnasien) weisen eine ähnlich niedrige Performanz auf. In Klassenstufe 6 (N = 472, Realschulen) erweist sich das operationalisierte Konstrukt als eindimensional; in einer Interventionsstudie (n = 320) wurden dort keine Effekte des untersuchten Treatments festgestellt. Die Befunde legen Maßnahmen zur Steigerung der Sensitivität, Validität und Reliabilität des vorgestellten Messinstruments nahe. Überdies erscheint es lohnenswert zu klären, ob die Kombination aus ökologischen Realexperimenten, dem Training systemischen Denkens und PC-Simulationen eine spätere Förderung der anspruchsvollen Fähigkeit begünstigen könnte

AAZTA5/AAZTA5-TOC: synthesis and radiochemical evaluation with 68Ga, 44Sc and 177Lu

AAZTA (1,4-bis (carboxymethyl)-6-[bis (carboxymethyl)]amino-6-methylperhydro-1,4-diazepine) based chelators were initially developed in the context of magnetic resonance imaging. First radiochemical studies showed the capability of AAZTA to form stable complexes with radiolanthanides and moderately stable complexes with 68Ga. For a systematic comparison of the labelling capabilities with current diagnostic and therapeutic trivalent radiometals, AAZTA5 (1,4-bis (carboxymethyl)-6-[bis (carboxymethyl)]amino-6-[pentanoic-acid]perhydro-1,4-diazepine) was synthesized representing a bifunctional version with a pentanoic acid at the carbon-6 atom. To evaluate the effect of adding a targeting vector (TV) to the bifunctional chelator on the complex formation, AAZTA5-TOC was synthesized, radiolabeled and tested in comparison to the uncoupled AAZTA5

Akkumulation von amorphem Silizium in holozänen Seesedimenten des Herrenwieser Sees (Nordschwarzwald)

Datierte Seesedimente sind Geoarchive, welche klimagesteuerte biogeochemische Prozesse im Einzugsgebiet aber auch gewässerinterne Prozesse widerspiegeln. Im Rahmen des DFG-PAK 179 analysierten wir in datierten Sedimentkernen des Herrenwieser Sees (Nordschwarzwald) verschiedene Si-Fraktionen und Gehalte weiterer Elemente, um daraus Aussagen über die längerfristige Elementdynamik in den Böden des Einzugsgebiets abzuleiten. Das mit Hilfe von heißer NaOH aufschließbare amorphe („biogene“) Silizium, welches v.a. die Diatomeen-Produktion eines Sees widerspiegelt (vgl. Conley, 1998; Sauer et al., 2006), ist eng gekoppelt an die Klimaschwankungen während des Holozäns. Vor allem im feucht-warmen Atlantikum (HTM-Holocene-Thermal-Maximum) weisen die Bioproduktion im untersuchten See und damit das Kieselalgenwachstum die höchsten Gehalte auf

Prospects of increase of efficiency of functioning of insurance companies through the development of information systems

Russian companies have already been solved (or solved) issues automated support of business processes of insurance. Another aspect of it application in the insurance, which to date remains one of the most important is to support decision-making in the claim process, as it depends largely on the economic condition of the insurance company. To resolve this problem, the development of information systems, the inclusion in their structure of intellectual component, reducing the probability of errors when making decisions. The work of this component is based on the principles of the decision theory and artificial intelligence, uses the mathematical apparatus of decision-making in conditions of uncertainty and risk and is a tool that interacts with the information system of the company

Labeling of DOTA-conjugated HPMA-based polymers with trivalent metallic radionuclides for molecular imaging

Background In this work, the in vitro and in vivo stabilities and the pharmacology of HPMA-made homopolymers were studied by means of radiometal-labeled derivatives. Aiming to identify the fewer amount and the optimal DOTA-linker structure that provides quantitative labeling yields, diverse DOTA-linker systems were conjugated in different amounts to HPMA homopolymers to coordinate trivalent radiometals Me(III)* = gallium-68, scandium-44, and lutetium-177. Results Short linkers and as low as 1.6% DOTA were enough to obtain labeling yields > 90%. Alkoxy linkers generally exhibited lower labeling yields than alkane analogues despite of similar chain length and DOTA incorporation rate. High stability of the radiolabel in all examined solutions was observed for all conjugates. Labeling with scandium-44 allowed for in vivo PET imaging and ex vivo measurements of organ distribution for up to 24 h. Conclusions This study confirms the principle applicability of DOTA-HPMA conjugates for labeling with different trivalent metallic radionuclides allowing for diagnosis and therapy

Translational assessment of a DATA-functionalized FAP inhibitor with facile 68Ga-labeling at room temperature.

PURPOSE The present study aims at evaluating the preclinical and the clinical performance of [68Ga]Ga-DATA5m.SA.FAPi, which has the advantage to be labeled with gallium-68 at room temperature. METHODS [68Ga]Ga-DATA5m.SA.FAPi was assessed in vitro on FAP-expressing stromal cells, followed by biodistribution and in vivo imaging on prostate and glioblastoma xenografts. Moreover, the clinical assessment of [68Ga]Ga-DATA5m.SA.FAPi was conducted on six patients with prostate cancer, aiming on investigating, biodistribution, biokinetics, and determining tumor uptake. RESULTS [68Ga]Ga-DATA5m.SA.FAPi is quantitatively prepared in an instant kit-type version at room temperature. It demonstrated high stability in human serum, affinity for FAP in the low nanomolar range, and high internalization rate when associated with CAFs. Biodistribution and PET studies in prostate and glioblastoma xenografts revealed high and specific tumor uptake. Elimination of the radiotracer mainly occurred through the urinary tract. The clinical data are in accordance with the preclinical data concerning the organ receiving the highest absorbed dose (urinary bladder wall, heart wall, spleen, and kidneys). Different to the small-animal data, uptake of [68Ga]Ga-DATA5m.SA.FAPi in tumor lesions is rapid and stable and tumor-to-organ and tumor-to-blood uptake ratios are high. CONCLUSION The radiochemical, preclinical, and clinical data obtained in this study strongly support further development of [68Ga]Ga-DATA5m.SA.FAPi as a diagnostic tool for FAP imaging