Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 2. Hydrochemical studies on mountain rivers in Ceylon

The morphology, climate, geology and geochemistry of Sri Lanka is briefly described. The separation into a wet zone (the south-west and greater part of the central highland) and a dry zone with two very dry parts in the south-east and in the north-west, is obvious and has great influence on the hydrochemistry of the island. Geology is very homogenous (Precambrian crystalline series) and some Jurassic and Miocene limestones (only in the north)

Comment on Mie Scattering from a Sonoluminescing Bubble with High Spatial and Temporal Resolution [Physical Review E 61, 5253 (2000)]

A key parameter underlying the existence of sonoluminescence (SL)is the time relative to SL at which acoustic energy is radiated from the collapsed bubble. Light scattering is one route to this quantity. We disagree with the statement of Gompf and Pecha that -highly compressed water causes the minimum in scattered light to occur 700ps before SL- and that this effect leads to an overestimate of the bubble wall velocity. We discuss potential artifacts in their experimental arrangement and correct their description of previous experiments on Mie scattering.Comment: 10 pages, 2 figure

Sonoluminescence: Nature's Smallest BlackBody

The Spectrum of the light emitted by a sonoluminescing bubble is extremely well fit by the spectrum of a blackbody. Furthermore the radius of emission can be smaller than the wavelength of the light. Consequences, for theories of sonoluminescence are discussed.Comment: 8 pages, 3 Figure

Gruta Nova da Columbeira (Bombarral, Portugal): Fundplatz-Stratigraphie, Alter der Moustérien-Schichtenfolge, und Schlussfolgerungen für die Chronologie des Aussterbens der Neanderthaler auf der Iberischen Halbinsel

The Gruta Nova da Columbeira is recurrently mentioned in the literature concerning the Middle-to-Upper Palaeolithic transition in Iberia as documenting the persistence beyond 30 000 calendar years ago of a Neanderthal-associated Mousterian. This claim is based on conventional radiocarbon dates obtained in the 1960’s and the 1970’s. In order to assess its validity, we undertook archival research to obtain unpublished details concerning the actual composition and chemistry of the dated samples, replicated the dating of samples of the same kind (carbonaceous sediments) and collected in the same deposits from the back of the cave whence came the 1970’s results, and obtained an U-series age estimate for a bone tool from the base of the Mousterian sequence excavated at the entrance of the cave in 1962. We then cross-checked all the stratigraphic and dating information thus assembled against the original field documents. Our results show that (a) the cave entrance sequence formed between MIS-5 and early MIS-3, (b) the deposits at the back of the cave probably formed in the Tardiglacial, and (c) the presence in these deposits of significant amounts of inherited charcoal derived from the entrance area explains the “Early Upper Palaeolithic” (EUP) age determinations obtained for the 1970’s samples. The association of such determinations with the Mousterian has been based on an unwarranted assumption of lateral stratigraphic continuity. While the entrance deposits correspond to an in situ Mousterian sequence, those from the back of the cave are primarily made of clay accumulated under temporary waterlogged conditions, with the few artefacts of Middle Palaeolithic affinities recovered therein being in secondary position. The evidence from Gruta Nova can no longer be used to counter the existence of a late Aurignacian in the region. In southern and western Iberia, the Neandertal-to-modern and Middle-to-Upper Palaeolithic transitions occurred no later than about 37 000 years ago.Auf der Grundlage konventioneller Radiokarbondaten aus den 1960er und 1970er Jahren werden Grabungsergebnisse aus der Gruta Nova da Columbeira (Bombarral) in der Fachliteratur auch heute noch verschiedentlich als Beleg für eine zeitliche Überlappung des späten Moustérien mit dem älterem Jungpaläolithikum genannt. Die unerwartet jungen 14C-Daten werden weiterhin als Beleg für eine Fortdauer der Neanderthaler bis in eine Zeit jünger als 30 000 Jahre vor heute herangezogen. Zur Überprüfung dieser Hypothese haben wir zahlreiche historische Dokumente zu den früheren Grabungen, wie auch der 14C-Datierungen, zusammengestellt und einer kritischen Sichtung unterzogen. Mit Hilfe der historischen Grabungsdokumente konnten zahlreichen Details der ursprünglichen Stratigraphie von Gruta Nova rekonstruiert werden. Auf dieser Grundlage wurden dann gezielt Nachuntersuchungen vorgenommen, um Probenmaterial zur erneuten 14C-Datierung aus gleicher stratigraphischer Position zu erhalten. Ferner wurde eine U/Th-Datierung an einem Knochenwerkzeug des Moustérien aus der Basis der Schicht 8 vorgenommen. Die Datierungsergebnisse zeigen, (1) dass es am Höhleneingang tatsächlich Fundschichten mit Artefakten gibt, die zwischen MIS-5 und MIS-3 datieren, aber (2), dass die ursprünglich anhand der 14C-Daten als ein „frühes Jungpaläolithikum“ interpretierten Schichten im rückwärtigen Teil der Höhle wahrscheinlich aus dem Spätglazial und durch Sedimente mit alten Holzkohlen aus dem Eingangsbereich kontaminiert wurden. Wie die Rekonstruktion der stratigraphischen Situation zeigt, gibt es in Gruta Nova — bei den heute nicht mehr akzeptablen 14C-Daten — keine ernstzunehmenden Indizien für die Existenz eines späten Moustérien. Damit liegt auch kein Beleg für einen späten Übergang - nach 37 000 Jahren vor heute - vom Mittel- zum Jungpaläolithikum im südlichen und westlichen Bereich der Iberischen Halbinsel vor

A supraomohyoidal plexus block designed to avoid complications

Interscalene blocks of the brachial plexus are used for surgery of the shoulder and are frequently associated with complications such as temporary phrenic block, Horner syndrome or hematoma. To minimize the risk of these complications, we developed an approach that avoids medially directed needle advancement and favors spread to lateral regions only: the supraomohyoidal block. We tested this procedure in 11 cadavers fixed by Thiel's method. The insertion site is at the lateral margin of the sternocleidomastoid muscle at the level of the cricoid cartilage. The needle is inserted in the axis of the plexus with an angle of approximately 35° to the skin, and advanced in lateral and caudal direction. Distribution of solution was determined in ten cadavers after bilateral injection of colored solution (20 and 30ml) and followed by dissection. In an eleventh cadaver, computerized tomography and 3D reconstruction after radio contrast injection was performed. In additional five cadavers we performed Winnie's technique with bilateral injection (20 and 30ml).Concerning the supraomohyoidal block the injection mass reached the infraclavicular region surrounded all trunks of the brachial plexus in the supraclavicular region and the suprascapular nerve in all cases. The solution did not spread medially beyond the lateral margin of the anterior scalene muscle into the scalenovertebral triangle. Therefore, phrenic nerve, stellate ganglion, laryngeal nerve nor the vertebral artery were exposed to the injected solution. Distribution was comparable with the use of 20 and 30ml of solution. Injections on five cadavers performing the interscalene block of Winnie resulted in an extended spread medially to the anterior scalene muscle.We conclude that our method may be a preferred approach due to its safety, because no structures out of interest were reached. Solution of 20ml is suggested to be enough for a successful bloc

An Alternative Method to Deduce Bubble Dynamics in Single Bubble Sonoluminescence Experiments

In this paper we present an experimental approach that allows to deduce the important dynamical parameters of single sonoluminescing bubbles (pressure amplitude, ambient radius, radius-time curve) The technique is based on a few previously confirmed theoretical assumptions and requires the knowledge of quantities such as the amplitude of the electric excitation and the phase of the flashes in the acoustic period. These quantities are easily measurable by a digital oscilloscope, avoiding the cost of expensive lasers, or ultrafast cameras of previous methods. We show the technique on a particular example and compare the results with conventional Mie scattering. We find that within the experimental uncertainties these two techniques provide similar results.Comment: 8 pages, 5 figures, submitted to Phys. Rev.

Calpain cleavage of Junctophilin-2 generates a spectrum of calcium-dependent cleavage products and DNA-rich NT1-fragment domains in cardiomyocytes

Calpains are calcium-activated neutral proteases involved in the regulation of key signaling pathways. Junctophilin-2 (JP2) is a Calpain-specific proteolytic target and essential structural protein inside Ca2+ release units required for excitation-contraction coupling in cardiomyocytes. While downregulation of JP2 by Calpain cleavage in heart failure has been reported, the precise molecular identity of the Calpain cleavage sites and the (patho-)physiological roles of the JP2 proteolytic products remain controversial. We systematically analyzed the JP2 cleavage fragments as function of Calpain-1 versus Calpain-2 proteolytic activities, revealing that both Calpain isoforms preferentially cleave mouse JP2 at R565, but subsequently at three additional secondary Calpain cleavage sites. Moreover, we identified the Calpain-specific primary cleavage products for the first time in human iPSC-derived cardiomyocytes. Knockout of RyR2 in hiPSC-cardiomyocytes destabilized JP2 resulting in an increase of the Calpain-specific cleavage fragments. The primary N-terminal cleavage product NT1 accumulated in the nucleus of mouse and human cardiomyocytes in a Ca2+-dependent manner, closely associated with euchromatic chromosomal regions, where NT1 is proposed to function as a cardio-protective transcriptional regulator in heart failure. Taken together, our data suggest that stabilizing NT1 by preventing secondary cleavage events by Calpain and other proteases could be an important therapeutic target for future studies