The orbital record in stratigraphy

Orbital signals are being discovered in pre-Pleistocene sediments. Due to their hierarchical nature these cycle patterns are complex, and the imprecision of geochronology generally makes the assignment of stratigraphic cycles to specific orbital cycles uncertain, but in sequences such as the limnic Newark Group under study by Olsen and pelagic Cretaceous sequence worked on by our Italo-American group the relative frequencies yield a definitive match to the Milankovitch hierarchy. Due to the multiple ways in which climate impinges on depositional systems, the orbital signals are recorded in a multiplicity of parameters, and affect different sedimentary facies in different ways. In platform carbonates, for example, the chief effect is via sea-level variations (possibly tied to fluctuating ice volume), resulting in cycles of emergence and submergence. In limnic systems it finds its most dramatic expression in alternations of lake and playa conditions. Biogenic pelagic oozes such as chalks and the limestones derived from them display variations in the carbonate supplied by planktonic organisms such as coccolithophores and foraminifera, and also record variations in the aeration of bottom waters. Whereas early studies of stratigraphic cyclicity relied mainly on bedding variations visible in the field, present studies are supplementing these with instrumental scans of geochemical, paleontological, and geophysical parameters which yield quantitative curves amenable to time-series analysis; such analysis is, however, limited by problems of distorted time-scales. My own work has been largely concentrated on pelagic systems. In these, the sensitivity of pelagic organisms to climatic-oceanic changes, combined with the sensitivity of botton life to changes in oxygen availability (commonly much more restricted in the Past than now) has left cyclic patterns related to orbital forcing. These systems are further attractive because (1) they tend to offer depositional continuity, and (2) presence of abundant microfossils yields close ties to geochronology. A tantalizing possibility that stratigraphy may yield a record of orbital signals unrelated to climate has turned up in magnetic studies of our Cretaceous core. Magnetic secular variations here carry a strong 39 ka periodicity, corresponding to the theoretical obliquity period of that time - Does the obliquity cycle perhaps have some direct influence on the magnetic field

Four-fold structure of vortex core states in Bi2Sr2CaCu2O8 (Bi2212)

We present a detailed study of vortex core spectroscopy in slightly overdoped Bi2Sr2CaCu2O8 using a low temperature scanning tunneling microscope. Inside the vortex core we observe a four-fold symmetric modulation of the local density of states with an energy-independent period of (4.3\pm 0.3)a0. Furthermore we demonstrate that this square modulation is related to the vortex core states which are located at ~6 meV. Since the core-state energy is proportional to the superconducting gap magnitude, our results strongly suggest the existence of a direct relation between the superconducting state and the local electronic modulations in the vortex core.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter

Stratigraphic rhythms synthesized from orbital variations

Previous work on a pelagic stratigraphic sequence in the Middle Cretaceous (Albian) of Italy, about 100 Ma, defined a hierarchy of oscillations. These were identified as variations in carbonate productivity and bottom fauna linked to seafloor aeration. The sequence geometry suggests response to orbitally driven climatic variations, reflecting Berger's precession index, which depicts the precession cycle as a carrier wave modulated by orbital eccentricity. Here we use Berger's astronomic precession index curve for the past 1,500 k.y. in combination with the stratigraphic data to construct a forward model of sedimentation and stratigraphy. The precession index curve serves as a point of departure, and modeling proceeds in three steps: (1) conversion of the precession index into a curve of sedimentation rates through time, using the flux rates calculated from the stratigraphy and applied in a nonlinear way; (2) conversion of that curve into an ideal stratigraphy in which the time dimension is changed into the spatial dimension of stratigraphy; and (3) modification of this stratigraphy by bioturbation as a nonlinear function of seafloor aeration. This computer simulation produces a reasonably good match to the observed stratigraphy. Perhaps more important is the insight gained into changes in the distribution of spectral power; whereas the power of the precession index lies wholly in the precessional terms, that of the stratigraphic sequence lies largely in the eccentricity frequencies. Our model shows how power is transferred from one to the other in each of the three steps. The spectrum of the ultimate stratigraphy synthesized is essentially identical with that of the natural sequence

Macromolecules and Enzymes: The Geneva Heritage from Kurt H. Meyer and Edmond H. Fischer

On the 26th May 2009, Edmond Fischer, winner with Ed Krebs of the Nobel prize in physiology or medicine in 1992, and his colleague at the time of his research activities at the Ecole de chimie of the University of Geneva, Alfred Piguet, met with Andreas Hauser, Claude Piguet and Howard Riezman of the Section de chimie et biochimie of the University of Geneva to talk about how they became scientists under the impetus of Kurt H. Meyer and what became of them thereafter

Stratigraphic rhythms synthesized from orbital variations

Previous work on a pelagic stratigraphic sequence in the Middle Cretaceous (Albian) of Italy, about 100 Ma, defined a hierarchy of oscillations. These were identified as variations in carbonate productivity and bottom fauna linked to seafloor aeration. The sequence geometry suggests response to orbitally driven climatic variations, reflecting Berger's precession index, which depicts the precession cycle as a carrier wave modulated by orbital eccentricity. Here we use Berger's astronomic precession index curve for the past 1,500 k.y. in combination with the stratigraphic data to construct a forward model of sedimentation and stratigraphy. The precession index curve serves as a point of departure, and modeling proceeds in three steps: (1) conversion of the precession index into a curve of sedimentation rates through time, using the flux rates calculated from the stratigraphy and applied in a nonlinear way; (2) conversion of that curve into an ideal stratigraphy in which the time dimension is changed into the spatial dimension of stratigraphy; and (3) modification of this stratigraphy by bioturbation as a nonlinear function of seafloor aeration. This computer simulation produces a reasonably good match to the observed stratigraphy. Perhaps more important is the insight gained into changes in the distribution of spectral power; whereas the power of the precession index lies wholly in the precessional terms, that of the stratigraphic sequence lies largely in the eccentricity frequencies. Our model shows how power is transferred from one to the other in each of the three steps. The spectrum of the ultimate stratigraphy synthesized is essentially identical with that of the natural sequence

Cameral deposits in cephalopod shells

30 p., 4 pl., 8 fig.http://paleo.ku.edu/contributions.htm

Specific immunotherapy in Albanian patients with anaphylaxis to hymenoptera venoms

Background: Severe allergic reactions during rush-specific immunotherapy (Rush-SIT) may occur in the treatment of hymenoptera sting allergy. The objective of the present study was to examine the characteristics of allergic reactions during Rush-SIT in a cohort of patients with allergy towards hymenoptera venom in the mediterranean population of Albania. Methods: A retrospective study was performed using the clinical reports of 37 patients with venom of bee (apinae), wasp (vespidae, subfamily vespinae) or paperwasp (vespidae, subfamily polistinae) allergy treated with Rush-SIT between 1987 and 1996. After hymenoptera sting allergy diagnosis according to anamnesis and intracutaneous tests the patient were treated with Rush-SIT. The protocol lasted 3 - 4 d with an increase in the concentration from 0.01 microg/ml to 100 microg/ml. Anaphylactic reactions were classified according to the Mueller-classification. Results: The frequency of reactions during Rush-SIT for bee-venom was 4.7% and for wasp-venom was 1.5% (p < 0.01). The mean frequency of reactions of Mueller grade II for the bee-venom Rush-SIT patients during the first 4 d (= 26 injections) was 0.73 and for the wasp-venom Rush-SIT patients 0.15. No patient experienced a third-degree reaction. 94.6% of the patient supported an end dose of 100 microg. Conclusions: Rush-SIT is a reliable method for the treatment of anaphylactic reactions to hymenoptera venom even in less developed countries. Bee-venom Rush-SIT was found to cause higher numbers allergic reactions than wasp or paperwasp Rush-SIT

A Few More Days: Budapest Diary 1944

„Dragi oče, zar nije neobično da Ti pišem 75 godina nakon Tvoje pogibije? Zar nije neobično da Ti pišem, a Ti ćeš ovo pismo pročitati samo u mojoj mašti? Neobičan je i poticaj na koji Ti pišem. No pisat ću Ti kao da ćeš Ti ovo pismo stvarno čitati, pisat ću Ti o onome što mislim da bi Te zanimalo. Pitat ću Te i kako bi Ti, da si mogao prisustvovati događajima koje ću opisati, na njih reagirao, bi li Te veselili ili rastužili. Poticaj za ovo pismo došao je od nekih Osječana koji su tražeći podatke o Kamilu Firingeru, Tvom kolegi, osječkom advokatu i čovjeku koji nas je spasio prebacivši nas ilegalno u Mađarsku u travnju 1943, došli i do mene, Tvoga sina, a ja sam im uručio prijepis Tvoga ratnog dnevnika iz nesretne ratne 1944. godine. Taj Tvoj dnevnik, mali dio onoga što si u svojoj samoći i neizvjesnosti ratnih strahota pisao u ono grozno vrijeme rata i Holokausta, taj mali dio Tvojih razmišljanja i uspomena ostao je čudom sačuvan, našla ga je naša mama sakrivenog u jednoj fotelji. Dugo je taj tekst ostao u rukopisu u strogo čuvanim porodičnim okvirima. Na moju inicijativu Tvoja unuka, Lelina kći, pretipkala ga je. I evo, sada ga objavljuju. Koliko bi zbog toga bio sretan Ti, naša mama i Lela, to ne znam. No od svih nas samo sam ja još na životu i preuzeo sam odgovornost da se Tvoj dnevnik objavi. Tvoj sin Darko (Fišer)...“"Dear father, isn't it strange that I am writing to You 75 years after Your death?" Isn't it strange that I write to You, and You will read this letter only in my imagination? The motivation for which I am writing to you is also unusual. But I will write to You as if You will read this letter. I will write to You about what I think could interest You. I will also ask you how, if you could be present at the events I will describe, you would react to them, whether they would make you happy or sad. The impetus for this letter came from some people from Osijek who, looking for information about Kamil Firinger, your colleague, a lawyer from Osijek and the man who saved us by illegally transferring us to Hungary in April 1943, came to me, your son. I gave them a copy of your war diary from the unfortunate war year 1944. Your diary, a small part of what you wrote in your loneliness and uncertainty of the horrors of war during that terrible time of war and the Holocaust, that small part of your thoughts and memories was miraculously preserved. Our mother found it hidden in an armchair. For a long time, that text remained in the manuscript in a strictly guarded family frame. On my initiative, your granddaughter, Lela's daughter, retyped it. And here, they publish it now. I don't know how happy you, our mom and Lela would be because of that. But of all of us, I am the only one still alive, and I have taken responsibility for your diary to be published. Your son Darko (Fisher)..."Biblioteka svagdan (9. knjiga)

Germanium Plasmonic Nanoantennas for Third-Harmonic Generation in the Mid Infrared

We explore the nonlinear optical properties of plasmonic semiconductor antennas resonant in the mid infrared. The nanostructures are fabricated on silicon substrates from heavily doped germanium films with a plasma frequency of 30 THz, equivalent to a wavelength of 10 μm. Illumination with ultrashort pulses at 10.8 μm produces coherent emission at 3.6 μm via third-harmonic generation