Degenerations of Jordan Superalgebras

We describe degenerations of three-dimensional Jordan superalgebras over $\mathbb{C}$. In particular, we describe all irreducible components in the corresponding varieties.Comment: arXiv admin note: text overlap with arXiv:1611.0645

Intensity noise self-regulated solid-state laser at 1.5μ{\mu}m using an ASHG based Buffer Reservoir

An absorption mechanism based on second-harmonic generation (ASHG) is successfully implemented as a buffer reservoir in a solid-state Er,Yb:Glass laser emitting at telecom wavelength. We show that a slight ASHG rate conversion of 0.016% using a BBO crystal enables to cancel out the excess intensity noise at the relaxation oscillation frequency, i.e. 35 dB reduction, as well as to cancel the amplified spontaneous emission beating at the free spectral range resonances of the laser lying in the GHz range.Comment: 6 pages, 5 figure

A context for the last Neandertals of interior Iberia: Los Casares cave revisited

<div><p>Introduction and objectives</p><p>Although the Iberian Peninsula is a key area for understanding the Middle to Upper Paleolithic transition and the demise of the Neandertals, valuable evidence for these debates remains scarce and problematic in its interior regions. Sparse data supporting a late Neandertal persistence in the Iberian interior have been recently refuted and hence new evidence is needed to build new models on the timing and causes of Neandertal disappearance in inland Iberia and the whole peninsula. In this study we provide new evidence from Los Casares, a cave located in the highlands of the Spanish Meseta, where a Neandertal-associated Middle Paleolithic site was discovered and first excavated in the 1960’s. Our main objective is twofold: (1) provide an updated geoarcheological, paleoenvironmental and chronological framework for this site, and (2) discuss obtained results in the context of the time and nature of the last Neandertal presence in Iberia.</p><p>Methods</p><p>We conducted new fieldwork in an interior chamber of Los Casares cave named ‘Seno A’. Our methods included micromorphology, sedimentology, radiocarbon dating, Uranium/Thorium dating, palinology, microfaunal analysis, anthracology, phytolith analysis, archeozoology and lithic technology. Here we present results on site formation processes, paleoenvironment and the chronological setting of the Neandertal occupation at Los Casares cave-Seno A.</p><p>Results and discussion</p><p>The sediment sequence reveals a mostly <i>in situ</i> archeological deposit containing evidence of both Neandertal activity and carnivore action in level c, dated to 44,899–42,175 calendar years ago. This occupation occurred during a warm and humid interval of Marine Isotopic Stage 3, probably correlating with Greenland Interstadial 11, representing one of the latest occurrences of Neandertals in the Iberian interior. However, overlying layer b records a deterioration of local environments, thus providing a plausible explanation for the abandonment of the site, and perhaps for the total disappearance of Neandertals of the highlands of inland Iberia during subsequent Greenland Stadials 11 or 10, or even Heinrich Stadial 4. Since layer b provided very few signs of human activity and no reliable chronometric results, and given the scarce chronostratigrapic evidence recorded so far for this period in interior Iberia, this can only be taken as a working hypothesis to be tested with future research. Meanwhile, 42,000 calendar years ago remains the most plausible date for the abandonment of interior Iberia by Neandertals, possibly due to climate deterioration. Currently, a later survival of this human species in Iberia is limited to the southern coasts.</p></div

Wood charcoal identified in Los Casares cave-Seno A.

<p>Wood charcoal identified in Los Casares cave-Seno A.</p

Selected areas of thin sections scanned under PPL and XPL conditions for illustration of some stratigraphic details on a larger scale.

<p>The scale bar represents 10 mm. A and B show the prominent dark colored interface between levels b and c1 in profile 3R. Note the low degree of compaction above the interface and the high packings density below it. In the upper part, linear accumulation of charcoal and manganese indicate former surfaces. C and D include a local accumulation of bone fragments with abundant phosphate infillings. Phosphate also precipitated in the outer part of the limestone gravel on the left. E and F include the sequence from level a3 at the top over a4, b0 to b at the bottom with sublayers of thin section 5/1. Note the strong compaction and linear lamination of the central layer (b0) and the remnants of textural surface crusts near the bottom. G and H is a close up of the boundary between b2 (top 3 cm) and c (bottom cm) in profile 8W. Under crossed polarization foils, the intercalation between clay rich and sandy layers with small gravel is visible.</p

Microphotographs of phytoliths identified at level c Los Casares cave-Seno A.

<p>Pictures were taken at 400x. A) Rondel short cell; characteristic of <i>Pooideae</i> grass subfamily; B) Saddle short cell characteristic of the <i>Chlorodoideae</i> grass subfamily; C) Crenate; phytolith characteristic of <i>Pooideae</i> grass subfamily (<i>Gramineae</i>); D) Elongate echinate from inflorescence of <i>Poaceae</i> (<i>Gramineae</i>).</p

The profile of 8-W’ with location of sampling for micromorphology and scans of three thin sections including stratigraphy and compacted surfaces.

<p>The profile of 8-W’ with location of sampling for micromorphology and scans of three thin sections including stratigraphy and compacted surfaces.</p

Main bone alterations documented in level c.

<p>Main bone alterations documented in level c.</p

Distribution of small vertebrates identified in Los Casares cave-Seno A.

<p>A: Percentage of identified taxa per stratigraphic layer. B: Distribution (#) of analyzed samples, identified taxa (S) and Minimum Number of individuals (MNI).</p

Technological categories with respect to lithic raw materials identified at level c of Los Casares cave-Seno A.

<p>Technological categories with respect to lithic raw materials identified at level c of Los Casares cave-Seno A.</p