Petrographic study of the Bronze Age ceramics from Shahr-I Sokhta in east of Iran

The Shahr-i Sokhta (The Burnt City) is a Bronze Age archaeological site in east of Iran with several stages of settlements. A large number of pottery shred and excavated ceramics of this site shows its importance during fourth to second millennium BC. Based on the color of body-paste of found ceramics in Shahr-i Sokhta, they are classified into three “Red”, “Grey” and “Buff” ware groups. An analysis of the microstructure and chemical composition of these three groups is the main purpose of this study. To do so, nine samples (three for each group) were subjected to observation by optical microscope and then their thin sections were analyzed by PLM, micro XRF and SEM-EDX to investigate any differences of raw materials from which these ceramics were produced. The results demonstrated that both Red and Grey ware ceramics have similar compositions with high amount of Fe and difference of their color is most probably because of different kiln atmosphere in which the potteries were produced. On the other hand, the high percentage of Ca in the Buff ware samples showed this type of ceramics are made with another type of raw material; different source or prepared deliberately. Moreover, PLM and SEM studies illustrated there wasn’t any cover layer on these ceramics, and, a paste with fine particles created all the bodies. Also, the percentage of organic additions shamot in the body of Grey and Buff samples are low while in the Red ware ceramics it is totally absent

Pharmaceutical analysis for environmental samples: Individual and simultaneous determination of ciprofloxacin, ofloxacin and norfloxacin using an HPLC with fluorescence and UV detection with a wetland soil matrix

Two HPLC methods were developed for individual and simultaneous determination of ciprofloxacin, norfloxacin and ofloxacin for use in laboratory experiments producing large numbers of samples (100 s to 1000 s). Individual compound detection produced retention times between 1.5 and 2 min and simultaneous detection between 6.5 to 8 min. The methods are compatible with complex geomatrices, e.g. a wetland soil. These methods provide 1) detection limits in the low parts per-billion range; 2) decrease in retention times of 5-10 times for single compounds, and up to 2 times for simultaneous detection over published methods; and 3) require no solid phase extraction. © Taylor & Francis Group, LLC

Pigment spectroscopy analyses in Maltravieso cave, Spain

Maltravieso cave (Estremadura, Spain) was recently the subject of ATR-FTIR spectroscopy of 8 figures (four hand stencils, a red horse figure, a black bull figure, a pair of black lines, and a pair of brown lines). These artistic representations are composed of different colors including red, brown, and black figures. The analyses showed that different naturally occurred material compounds in the cave (such as kaolinite) were used in the creation of the ochre to obtain different hues. Hand stencils are made of earth pigment that is naturally present in the cave which contained hematite, magnetite, and goethite as chromophores material. The red horse figure was made with kaolinite-based ochre. The black bull figure was made with charcoal (identified with Raman spectroscopy). The pigmental composition analyses show that they are composed of the same natural matter found inside the cave. Our results suggest that different paintings in the cave have been produced by different techniques and these techniques are linked to different chronological periods

A multi-analytical evaluation of the depositional pattern on open-air rock art panels at “Abrigo del Lince” (Badajoz, Spain)

Microscopic observation correlated with chemical–mineralogical characterization was performed on pigment samples from “Abrigo del Lince” rock art site (V-IV millennium BC), in order to provide contributions to the study of prehistoric schematic art on granite in the province of Badajoz (Spain). The research objectives include the understanding of technological and cultural aspects, as well as of conservation and deterioration issues related to the pictographs. The multi-analytical approach encompasses the integration of microscopic observation, SEM–EDS analysis, micro-Raman spectroscopy, and ATR-FTIR and allowed to achieve a multispectral overview of the samples and to describe their varied composition and the alteration pattern which connects them. The main phases overlying the granitic bedrock and involved in this sequence are as follows: hematite, whewellite, and gypsum. While hematite could be stratigraphically considered the most ancient layer and assigned to the use of red ochre as a pigment, whewellite and gypsum are the main constituent of the alteration layer which forms a patina over the pictographs, due to weathering processes. Finally, the role of biofilms in rock art conservation is discussed, suggesting that, especially for what concern thin and homogenous layers of oxalates, their presence should not be necessarily considered an issue

Cytoplasmic Volume Modulates Spindle Size During Embryogenesis

Rapid and reductive cell divisions during embryogenesis require that intracellular structures adapt to a wide range of cell sizes. The mitotic spindle presents a central example of this flexibility, scaling with the dimensions of the cell to mediate accurate chromosome segregation. To determine whether spindle size regulation is achieved through a developmental program or is intrinsically specified by cell size or shape, we developed a system to encapsulate cytoplasm from Xenopus eggs and embryos inside cell-like compartments of defined sizes. Spindle size was observed to shrink with decreasing compartment size, similar to what occurs during early embryogenesis, and this scaling trend depended on compartment volume rather than shape. Thus, the amount of cytoplasmic material provides a mechanism for regulating the size of intracellular structures