RESUMO

This work presents a non-invasive material study of the Red Queen's funerary offering via in situ infrared (FTIR) and Raman spectroscopies for mineral identification, and X-ray fluorescence spectroscopy (XRF) for elemental characterization. A second non-destructive laboratory stage on the main mask of the offering only was carried out by particle induced X-ray emission (PIXE) for further elemental analysis. The main FTIR results indicate that all of the tesserae of the main mask are composed of malachite, identified by their ν(CuO), ν(CuOH), ν1-ν4(CO32-) and δ(CO32-) infrared and T(CO32-) Raman vibrational modes. Moreover, the pupils are composed of obsidian (δ(SiOSi) and ν(SiO) infrared vibrational modes), and remarkably, jadeite was identified in the sclera of the eyes. Most of the accompanying mask's tesserae are green quartz and chalcedony (δ(SiOSi) and ν(SiO) infrared and Raman vibrational modes). The pendants are made of jadeite, while the headdress´ tesserae were identified as omphacite. The diadem and necklace's green beads were mostly jadeite, omphacite and albite. Jadeite, albite and omphacite were identified through their characteristic infrared and Raman vibrational modes: ν(SiOSi), δ(SiOSi), τ(SiO4) and AlSiO4 interactions. Yellow-orange beads in the diadem and in the pectoral are quartz. Green and blue pectoral beads are jadeite, omphacite and quartz. Limestones and shells identified in the figurine, valve and in some of the headdress and accompanying mask's tesserae, were properly classified by Raman spectroscopy, using their characteristic ν1 and ν4 (CO32-) vibrational modes for aragonite and beta-carotenes characteristic Raman shifts for Spondylus valves. These results indicate a special selection and the use of unique raw materials for the royal burial of the Red Queen, different to those used for other rulers of Palenque and other contemporary Mayan sites.

RESUMO

The present paper proposes a methodology that complies with the requirements of identifying and characterizing jadeite (and its associated minerals) for archaeological studies, avoiding the acquisition of samples and ensuring the integrity of the object. The methodology exploits a carefully selected array of techniques (optical microscopy, UV fluorescence photography, X-Ray digital radiography, infrared and Raman spectroscopies, X-Ray fluorescence and particle induced X-ray emission spectroscopies) that, despite not definitively replacing laboratory procedures, provides a first mineral and elemental evaluation of jadeite archaeological objects. The proposed methodology was applied in the characterization of twelve different jade tones, allowing the identification of major - jadeite, albite and omphacite - and minor - pumpellyite, actinolite, analcime, rutile, grossular and titanite - mineral phases. To display its advantages and limitations, this methodology was also compared with a characterization employing specific gravity measurements and with an invasive methodology based on petrography and scanning electron microscopy with energy dispersive spectroscopy.

RESUMO

This paper presents toxicity and uptake data of Limnodrilus hoffmeisteri generated by lead in systems using natural sediments from Ignacio Ramírez reservoir. Lead uptake, hemoglobin concentration, and acetylcholinesterase activity were studied in L. hoffmeisteri exposed to spiked sediments. All assays of lead uptake were conducted using whole sediments. Sediment texture was also considered. Acetylcholinesterase activity and hemoglobin concentration decreased after treatment with lead. Acetylcholinesterase activity and hemoglobin concentration tests indicated a response to the concentration of lead. These results suggest the usefulness of a diversity of bioassays to evaluate the toxicity of sediments polluted with heavy metals.

Assuntos

RESUMO

The arthropod-borne virus (arbovirus) diseases of livestock have worldwide impact. The prevention of an introduction of an exotic disease and the control of one subsequent to an introduction will require the attention, cooperation, and support of the livestock industry, regulatory agencies, and researchers. The most effective protection of our livestock industries is to prevent the introduction of an exotic disease agent. This implies complete restriction of animal imports and exports. However, "zero risk" is an unacceptable option in today's world of internationally integrated and interdependent agriculture. Scientifically sound and factually based regulatory decisions must be combined with continued vigilance and preparedness, as well as appropriately directed surveillance and research, to protect the world agricultural marketplace. Two exotic arbovirus diseases that are of current concern to the livestock industries and regulatory officials of the North American and Caribbean Basin countries are VEE and AHS. Devastating epizootics of VEE in equines have occurred frequently in the Western Hemisphere, but no recent epizootic activity has been documented. Naturally occurring foci of sylvatic, equine nonpathogenic VEE virus subtypes, however, do exist in the tropical countries of the hemisphere. The relationship of these sylvatic virus foci to the origin of equine virulent epizootic VEE virus subtypes is unknown. AHS epizootics had been confined to Africa, the Middle East, and the Indian subcontinent until recent outbreaks in 1966 and 1987-1990 in Spain. With the recurrence of AHS in Spain for the past four years, concern about the possible introduction into potential vector species and equines in the Western Hemisphere has increased. This review addresses the current VEE and AHS virus activity and the potential for outbreaks in the Western Hemisphere.

Assuntos