Connections between the Levant and the Balkans in the late Middle Pleistocene: Archaeological findings from Velika and Mala Balanica Caves (Serbia).

Major changes in the technological, economic, and social behavior of Middle Pleistocene hominins occurred at the onset of the Middle Paleolithic, 400-200 ka. However, until recently it was not possible to establish when, where, and how certain forms of Middle Paleolithic behavior appeared and spread into Southeastern Europe, mainly owing to gaps in the Paleolithic record. Here we report new results of dating, material culture, and the archaeological context of finds from the Balanica Cave Complex in Sićevo (Serbia).

Decoration of Coiled-Coil Peptides with N-Cysteine Peptide Thioesters As Cyclic Peptide Precursors Using Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC) Click Reaction.

The development of a copper-catalyzed azide-alkyne cycloaddition (CuAAC) protocol for the decoration of coiled coils with N-cysteine peptide thioesters as cyclic peptide precursors is presented. The reaction conditions include tert-butanol/PBS as the solvent and CuSO/THPTA/ascorbate as the catalytic system. During these studies, partial formylation of N-terminal cysteine peptides is observed.

De Novo Designed α-Helical Coiled-Coil Peptides as Scaffolds for Chemical Reactions.

Coiled coils (CCs) are well-understood protein-folding motifs. They appear in a variety of oligomer states and as homo- and heteromeric assemblies. This versatility and the general accessibility by de novo design makes them ideal building blocks for synthetic biology.

Evidence of an early projectile point technology in North America at the Gault Site, Texas, USA.

American archeology has long been polarized over the issue of a human presence in the Western Hemisphere earlier than Clovis. As evidence of early sites across North and South America continues to emerge, stone tool assemblages appear more geographically and temporally diverse than traditionally assumed. Within this new framework, the prevailing models of Clovis origins and the peopling of the Americas are being reevaluated.

Kinetic studies on strand displacement in designed parallel heterodimeric coiled coils.

Among the protein folding motifs, which are accessible by design, the parallel heterodimeric coiled coil is most frequently used in bioinspired applications and chemical biology in general. This is due to the straightforward sequence-to-structure relationships, which it has in common with all coiled-coil motifs, and the heterospecificity, which allows control of association. Whereas much focus was laid on designing orthogonal coiled coils, systematic studies on controlling association, for instance by strand displacement, are rare.

Sequential Subterranean Transport of Excavated Sand and Foraged Seeds in Nests of the Harvester Ant, Pogonomyrmex badius.

During their approximately annual nest relocations, Florida harvester ants (Pogonomyrmex badius) excavate large and architecturally-distinct subterranean nests. Aspects of this process were studied by planting a harvester ant colony in the field in a soil column composed of layers of 12 different colors of sand. Quantifying the colors of excavated sand dumped on the surface by the ants revealed the progress of nest deepening to 2 m and enlargement to 8 L in volume.

New radiometric ages for the BH-1 hominin from Balanica (Serbia): implications for understanding the role of the Balkans in Middle Pleistocene human evolution.

Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 from Mala Balanica cave, Serbia. This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene. Inferences drawn from the morphology of the mandible BH-1 place it outside currently observed variation of European Homo heidelbergensis.

Single-aliquot EPR dosimetry of wallboard (drywall).

Electron paramagnetic resonance spectra and dose-response curves are presented for a variety of wallboard samples obtained from different manufacturing facilities, as well as for source gypsum and anhydrite. The intensity of the CO(3)(-) paramagnetic centre (G2) is enhanced with gamma radiation. Isothermal decay curves are used to propose annealing methods for the removal of the radiosensitive CO(3)(-) radical without affecting the unirradiated baseline.

Optically stimulated luminescence dosimetry with gypsum wallboard (drywall).

Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm).

Geochronology of cave deposits at Liang Bua and of adjacent river terraces in the Wae Racang valley, western Flores, Indonesia: a synthesis of age estimates for the type locality of Homo floresiensis.

A robust timeframe for the extant cave deposits at Liang Bua, and for the river terraces in the adjoining Wae Racang valley, is essential to constrain the period of existence and time of extinction of Homo floresiensis and other biota that have been excavated at this hominin type locality. Reliable age control is also required for the variety of artifacts excavated from these deposits, and to assist in environmental reconstructions for this river valley and for the region more broadly. In this paper, we summarize the available geochronological information for Liang Bua and its immediate environs, obtained using seven numerical-age methods: radiocarbon, thermoluminescence, optically- and infrared-stimulated luminescence (collectively known as optical dating), uranium-series, electron spin resonance, and coupled electron spin resonance/uranium-series.

Dating the demise: neandertal extinction and the establishment of modern humans in the southern Caucasus.

This paper considers the recent radiometric dating (14C-AMS, TL, ESR) of 76 late Middle and early Upper Paleolithic samples from Ortvale Klde Rockshelter, located in the Republic of Georgia. We present a critical evaluation of each date based on its stratigraphic and archaeological context, its pretreatment and contamination history, and its resulting accuracy and precision, the goal being to establish a sound chronology for the site. Only by systematically identifying aberrant dates within a data set and isolating them from further analysis can we hope to understand cultural and biological phenomena on an accurate temporal scale.

The Pech-de-l'Azé I Neandertal child: ESR, uranium-series, and AMS 14C dating of its MTA type B context.

The Pech-de-l'Azé I skull and mandible are included in the juvenile Neandertal remains from Europe. However, some preserved features in the cranial skeleton seem to distinguish the specimen from other Neandertal children. Unfortunately, the stratigraphic position and dating of this child has never been clear.

Retrospective radiation dosimetry using electron paramagnetic resonance in canine dental enamel.

Electron paramagnetic resonance (EPR) biodosimetry of human tooth enamel has been widely used for measuring radiation doses in various scenarios. We have now developed EPR dosimetry in tooth enamel extracted from canines. Molars and incisors from canines were cleaned by processing in supersaturated aqueous potassium hydroxide solution.

Archaeology and age of a new hominin from Flores in eastern Indonesia.

Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominins, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis. The finds comprise the cranial and some post-cranial remains of one individual, as well as a premolar from another individual in older deposits. Here we describe their context, implications and the remaining archaeological uncertainties.

Later Middle Pleistocene human remains from the Almonda Karstic system, Torres Novas, Portugal.

Later Middle Pleistocene archeological deposits of the Galeria Pesada (Gruta da Aroeira), Almonda Karstic System, Torres Novas, Portugal, yielded two archaic human teeth, a mandibular canine and a maxillary third molar. The C(1)presents moderate and asymmetrical shoveling with a stout root. The slightly worn M(3)exhibits at least four cusps with a large hypocone, three roots with large radicular plates, and an absence of taurodontism.

Biophysical dose measurement using electron paramagnetic resonance in rodent teeth.

Electron paramagnetic resonance (EPR) dosimetry of human tooth enamel has been widely used in measuring radiation doses in various scenarios. However, there are situations that do not involve a human victim (e.g.

Quantification of low dose signal in EPR tooth dosimetry--a novel approach.

For radiation exposures below 100 mGy, the dosimetric signal in tooth enamel is too small to be measured by using the traditional dose reconstruction procedure. This is because low amplitude zero-added-dose signal can not be identified in an EPR spectrometer. A technique is presented wherein, zero-added-dose signal.

ESR of E' centres in unstrained geological quartz grains.

E1' centres are detectable by ESR spectroscopy in unstrained quartz extracted from weathered rock of Cretaceous age. These centres completely disappear when the samples are irradiated with an artificial gamma-dose of about 200 Gy. The concentration of E1' centres thermally (re)generated at 310 degrees C can be reduced drastically under the influence of gamma-quanta, too.

ESR dating of the Die Kelders Cave 1 site, South Africa.

ESR measurements were made on ten enamel subsamples from six teeth recovered in layers 4-5, 6, 10, and 12 in the site of Die Kelders Cave 1, South Africa. The teeth (enamel and dentine) contained significant concentrations of uranium and therefore the U uptake model has a large influence on the computed ages. Variations in moisture content in the sediment had a smaller effect on the dose rate and calculated ages.

Latest Homo erectus of Java: potential contemporaneity with Homo sapiens in southeast Asia.

Hominid fossils from Ngandong and Sambungmacan, Central Java, are considered the most morphologically advanced representatives of Homo erectus. Electron spin resonance (ESR) and mass spectrometric U-series dating of fossil bovid teeth collected from the hominid-bearing levels at these sites gave mean ages of 27 +/- 2 to 53.3 +/- 4 thousand years ago; the range in ages reflects uncertainties in uranium migration histories.

Early Homo and associated artefacts from Asia.

The site of Longgupo Cave was discovered in 1984 and excavated in 1985-1988 by the Institute of Vertebrate Paleontology and Paleoanthropology (Beijing) and the Chongqing National Museum (Sichuan Province). Important finds include very archaic hominid dental fragments, Gigantopithecus teeth and primitive stone tools. Palaeomagnetic analysis and the presence of Ailuropoda microta (pygmy giant panda) suggested that the hominid-bearing levels dated to the earliest Pleistocene.

Dating and context of three middle stone age sites with bone points in the Upper Semliki Valley, Zaire.

The extent to which the earliest anatomically modern humans in Africa exhibited behavioral and cognitive traits typical of Homo sapiens sapiens is controversial. In eastern Zaire, archaeological sites with bone points have yielded dates older than 89(-15)+22 thousand years ago by several techniques. These include electron spin resonance, thermoluminescence, optically stimulated luminescence, uranium series, and amino acid racemization.

Giant radiation-induced color halos in quartz: solution to a riddle.

The radii of radiation-induced color halos(RICHs) surrounding radioactive mineral inclusions in mica generally correspond closely to the calculated range of common uranogenic and thorogenic alpha particles in mica. Many exceptions are known, however, and these variants have led investigators to some rather exotic interpretations. Three RICHs found in quartz are identified as aluminum hole-trapping centers.