Exploring the lack of articular ends at the Middle Pleistocene site of Qesem Cave, Israel

Biased skeletal part representation is a key element for making inferences about transport decisions, carcass procurement, and use patterns in anthropogenic accumulations. In the absence of destructive taphonomic processes, it is often assumed that the abundance of different anatomical portions represents selective transport and discard patterns of human groups. Because body parts may be transported for specific products such as meat, marrow or grease, a pattern that usually attracts attention in many archaeological sites is the low proportions of appendicular epiphyses. Here we present the case of faunal assemblages from the lower stratigraphic sequence of Qesem Cave, Israel, dated to ca. 430 to 300 ka. All bone accumulations are characterized by a biased skeletal profile including mainly long-limb bones and a virtual absence of epiphyses. The assemblages also show density-mediated attrition not linked to fossil-diagenetic processes, a targeted specific destruction to the most greasy articular ends and an almost total absence of carnivore intervention. Our goal here is to explore the processes that entail the destruction of appendicular epiphyses at Qesem Cave, as well as propose viable hypotheses to explain their underrepresentation on-site. Our results shed light on the domestic activities linked to the processing of bones at the site and support the importance of animal grease in the caloric intake of Middle Pleistocene humans.

Eurasian griffon vulture (Gyps fulvus) as a bone modifying agent and its implications for archaeology

Neo-taphonomic studies have allowed us to detect bone damage patterns linked to carnivore preferences and behavioral traits as well as to improve our understanding of the origin of different alterations on vertebrate fossil faunas. However, taphonomically speaking vultures are among the least studied of all common, obligate scavengers. The research reported here contributes to characterise Eurasian griffon vulture (Gyps fulvus) behavior from a taphonomic perspective describing bone damage on 12 small-sized ungulate carcasses. The combination of observational data from photo/video-trap together with taphonomic analyses allowed us to manage factors like feeding behavior or time of consumption, as well as to accurately record bone modified items. Some bone-modifying effects are described here for the first time as vulture-made bone-damage distinctiveness. Still, some others may pose equifinality problems especially regarding small carnivores. This taphonomic conundrum leaves an interpretation problem particularly in archaeological sites in which those agents are present and consequently, an individualization dilemma about the taphonomic actors involved in bone modified assemblages.

New quantitative method for dental wear analysis of small mammals

The application of dental wear study to murids has always been ruled out because of their omnivorous diet, which does not leave significant wear on the dentition. Nevertheless, in our work we select Apodemus sylvaticus (wood mouse) as the object of study for several reasons: its seasonal diet, its ability to resist the gastric juices of predators, the fact that it has not undergone major morphological changes since its appearance 3 million years ago, and its widespread distribution throughout much of Europe and part of Africa. The importance of this work lies in the modifications we make to the dental wear methodology for its application to murids. These enable us to obtain quantitative data on the entire tooth surface. The sample chosen was a total of 75 lower first molars from two different archaeological sites: Teixoneres cave and Xaragalls cave. The chronology of the samples chosen ranges from Marine Isotope Stages 5-3. The data obtained reveal that the part of the tooth that shows most wear is the distal part (entoconid). Furthermore, the results provide us with relevant information on the types of accumulations of remains in the caves (short vs. long term), as well as on the seasonality of Neanderthal occupations during the Upper Pleistocene (MIS5-3) of the northeastern Iberian Peninsula.

Speciated mechanism in Quaternary cervids (Cervus and Capreolus) on both sides of the Pyrenees: a multidisciplinary approach

Cervids, and especially the red deer Cervus elaphus, are among the most regularly and abundantly recorded ungulates in Pleistocene/Paleolithic bone assemblages. Numerous Pleistocene or Holocene subspecies have been described, reinforcing their status as essential proxies for environmental and chronological reconstructions. Despite this, at the beginning of the Late Pleistocene, their diversity seems to have decreased. In this study, we analysed teeth and some postcranial elements of Cervus and Capreolus from north-eastern Iberia and south-eastern France to clarify their morphological characteristics and ecological adaptations. We describe a transitional form in north-eastern Iberia between the western European stock and the current form C. e. hispanicus. Such sub-speciation processes are connected to biogeographical factors, as there were limited exchanges between north-eastern Iberia and the northern Pyrenees, whereas the north-western part of the peninsula seems more connected to the northern Pyrenees. The anatomical plasticity (morpho-functional adaptation and body size) of red deer is connected to dietary flexibility (dental meso- and microwear). Conversely, Capreolus shows greater morphological and ecological homogeneity. Body size variations seem directly correlated with their ability to browse throughout the year. The marked differences between the eco-bio-geographical responses of the two taxa can be explained by their habitat selection.

Comment on "A global environmental crisis 42,000 years ago"

Cooper et al. (Research Articles, 19 February 2021, p. 811) propose that the Laschamps geomagnetic inversion ~42 ka BP drove global climatic shifts, causing major behavioural changes within prehistoric groups, and events of human and megafaunal extinction. Other scientific studies indicate that this proposition is unproven from the current archaeological, paleoanthropological, and genetic records.

Examining Neanderthal and carnivore occupations of Teixoneres Cave (Moià, Barcelona, Spain) using archaeostratigraphic and intra-site spatial analysis

Teixoneres Cave (Moià, Barcelona, Spain) is a reference site for Middle Palaeolithic studies of the Iberian Peninsula. The cave preserves an extensive stratigraphic sequence made up of eight units, which is presented in depth in this work. The main goal of this study is to undertake an initial spatial examination of Unit III, formed during Marine Isotope Stage 3, with the aim of understanding spatial organization and past activities developed by Neanderthals and carnivores (bears, hyenas and smaller carnivores). The total sample analysed includes 38,244 archaeological items and 5888 limestone blocks. The application of GIS tools allows us to clearly distinguish three geologically-defined stratigraphic subunits. Unit III has been previously interpreted as a palimpsest resulting from alternating occupation of the cave by human groups and carnivores. The distribution study shows that faunal specimens, lithic artefacts, hearths and charcoal fragments are significantly concentrated at the entrance of the cave where, it is inferred, hominins carried out different activities, while carnivores preferred the sheltered zones in the inner areas of the cave. The results obtained reveal a spatial pattern characterized by fire use related zones, and show that the site was occupied by Neanderthals in a similar and consistent way throughout the ˃ 7000 years range covered by the analysed subunits. This spatial pattern is interpreted as resulting from repeated short-term human occupations.

Shaped stone balls were used for bone marrow extraction at Lower Paleolithic Qesem Cave, Israel

The presence of shaped stone balls at early Paleolithic sites has attracted scholarly attention since the pioneering work of the Leakeys in Olduvai, Tanzania. Despite the persistent presence of these items in the archaeological record over a period of two million years, their function is still debated. We present new results from Middle Pleistocene Qesem Cave on the use of these implements as percussion tools. Use-wear and abundant bone and fat residues found on ten shaped stone balls indicate crushing of fresh bones by thrusting percussion and provide direct evidence for the use of these items to access bone marrow of animal prey at this site. Two experiments conducted to investigate and verify functional aspects proved Qesem Cave shaped stone balls are efficient for bone processing and provide a comfortable grip and useful active areas for repeated use. Notably, the patina observed on the analyzed items precedes their use at the cave, indicating that they were collected by Qesem inhabitants, most probably from older Lower Paleolithic Acheulian sites. Thus, our results refer only to the final phases of the life of the items, and we cannot attest to their original function. As bone marrow played a central role in human nutrition in the Lower Paleolithic, and our experimental results show that the morphology and characteristics of shaped stone ball replicas are well-suited for the extraction of bone marrow, we suggest that these features might have been the reason for their collection and use at Qesem Cave. These results shed light on the function of shaped stone balls and are consistent with the significance of animal fat in the caloric intake of Middle Pleistocene humans as shown by the archeozoological evidence at Qesem Cave and possibly beyond.

Bone marrow storage and delayed consumption at Middle Pleistocene Qesem Cave, Israel (420 to 200 ka)

Bone marrow and grease constitute an important source of nutrition and have attracted the attention of human groups since prehistoric times. Marrow consumption has been linked to immediate consumption following the procurement and removal of soft tissues. Here, we present the earliest evidence for storage and delayed consumption of bone marrow at Qesem Cave, Israel (~420 to 200 ka). By using experimental series controlling exposure time and environmental parameters, combined with chemical analyses, we evaluated bone marrow preservation. The combination of archaeological and experimental results allowed us to isolate specific marks linked to dry skin removal and determine a low rate of marrow fat degradation of up to 9 weeks of exposure. This is the earliest evidence of such previously unidentified behavior, and it offers insights into the socio-economy of the human groups who lived at Qesem and may mark a threshold to new modes of Palaeolithic human adaptation.

Feathers and food: Human-bird interactions at Middle Pleistocene Qesem Cave, Israel

The presence of fast-moving small game in the Paleolithic archaeological faunal record has long been considered a key variable to assess fundamental aspects of human behavior and subsistence. Birds occupy a prominent place in this debate not only due to their small size and to the difficulties in capturing them (essentially due to their ability to fly and their elusiveness), but also due to their possible role in the symbolic array in regard to non-nutritional elements (feathers, talons, etc.) and as reflectors of complex human-world relationships. In this study, we attempt to contribute to this topic by presenting taphonomical data of bird specimens from Qesem Cave (Israel), dated between 420 and 200 ka. Human-induced damage, including cut marks, peeling and human gnawing, has been identified on wing bones of Cygnus sp., Columba sp., Corvus ruficollis and Sturnus sp. Our evidence suggests that avian exploitation was not limited to food only-either to complement the human diet or as occasional food item-but also presumably for the use of feathers. While the consumption of birds as a dietary source seems to be evident as early as the Early Pleistocene, the non-alimentary use of inedible elements, such as feathers and talons, appears to be a practice from the Middle Paleolithic onwards. We argue that the combined nutritional and symbolic use of birds is one characteristic of the new mode of adaptation practiced already by the late Lower Paleolithic Acheulo-Yabrudian hominins in the Levant starting 400 ka. The Qesem findings point to the possible emergence of new cognitive and behavioral skills, which are followed in later periods in the Old World. Finally, we discuss the possible ontological and cosmological significance of human-bird interactions to illuminate our hypothesis regarding the emergence of a new perception of human relationships with the world as an integral part of the new Acheulo-Yabrudian mode of adaptation.

Microwear and isotopic analyses on cave bear remains from Toll Cave reveal both short-term and long-term dietary habits

Dietary habits of the extinct Ursus spelaeus have always been a controversial topic in paleontological studies. In this work, we investigate carbon and nitrogen values in the bone collagen and dental microwear of U. spelaeus specimens recovered in Level 4 from Toll Cave (Moià, Catalonia, NE Iberian Peninsula). These remains have been dated to > 49,000 ¹⁴C BP. The ability of both proxies to provide data on the diet of U. spelaeus at different times in the life-history (isotopes: average diet of life; microwear: last days/weeks before death), allows us to generate high-resolution and complementary data. Our results show lower values (δ¹³C & δ¹⁵N) in cave bears than in strict herbivores (i.e. Cervus elaphus) recovered from the same level of Toll Cave. On the other hand, 12 lower molars (m1) were analysed through low-magnification microwear technique. The cave bears from Toll Cave show a microwear pattern like that of extant bears with omnivorous and carnivorous diets. These data are discussed in the framework of all available data in Europe and add new information about the plasticity of the dietary habits of this species at the southern latitudes of Europe during Late Pleistocene periods.

Intersubband absorption in GaN nanowire heterostructures at mid-infrared wavelengths

In this paper, we study intersubband characteristics of GaN/AlN and GaN/Al_0.4Ga_0.6N heterostructures in GaN nanowires structurally designed to absorb in the mid-infrared wavelength region. Increasing the GaN well width from 1.5 to 5.7 nm leads to a red shift of the intersubband absorption from 1.4 to 3.4 μm. The red shift in larger quantum wells is amplified by the fact that one of the GaN/AlN heterointerfaces (corresponding to the growth of GaN on AlN) is not sharp but rather a graded alloy extending around 1.5-2 nm. Using AlGaN instead of AlN for the same barrier dimensions, we observe the effects of reduced polarization, which blue shifts the band-to-band transitions and red shifts the intersubband transitions. In heavily doped GaN/AlGaN nanowires, a broad absorption band is observed in the 4.5-6.4 μm spectral region.

Early evidence of stone tool use in bone working activities at Qesem Cave, Israel

For a long while, the controversy surrounding several bone tools coming from pre-Upper Palaeolithic contexts favoured the view of Homo sapiens as the only species of the genus Homo capable of modifying animal bones into specialised tools. However, evidence such as South African Early Stone Age modified bones, European Lower Palaeolithic flaked bone tools, along with Middle and Late Pleistocene bone retouchers, led to a re-evaluation of the conception of Homo sapiens as the exclusive manufacturer of specialised bone tools. The evidence presented herein include use wear and bone residues identified on two flint scrapers as well as a sawing mark on a fallow deer tibia, not associated with butchering activities. Dated to more than 300 kya, the evidence here presented is among the earliest related to tool-assisted bone working intended for non-dietary purposes, and contributes to the debate over the recognition of bone working as a much older behaviour than previously thought. The results of this study come from the application of a combined methodological approach, comprising use wear analysis, residue analysis, and taphonomy. This approach allowed for the retrieval of both direct and indirect evidence of tool-assisted bone working, at the Lower Palaeolithic site of Qesem Cave (Israel).

Earliest evidence of pollution by heavy metals in archaeological sites

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

The earliest pigeon fanciers

Feral Pigeons have colonised all corners of the Earth, having developed a close association with humans and their activities. The wild ancestor of the Feral Pigeon, the Rock Dove, is a species of rocky habitats, nesting typically on cliff ledges and at the entrance to large caves. This habit would have brought them into close contact with cave-dwelling humans, a relationship usually linked to the development of dwellings in the Neolithic. We show that the association between humans and Rock Doves is an ancient one with its roots in the Palaeolithic and predates the arrival of modern humans into Europe. At Gorham's Cave, Gibraltar, the Neanderthals exploited Rock Doves for food for a period of over 40 thousand years, the earliest evidence dating to at least 67 thousand years ago. We show that the exploitation was not casual or sporadic, having found repeated evidence of the practice in different, widely spaced, temporal contexts within the cave. Our results point to hitherto unappreciated capacities of the Neanderthals to exploit birds as food resources on a regular basis. More so, they were practising it long before the arrival of modern humans and had therefore invented it independently.

Discontinuity of human presence at Atapuerca during the early Middle Pleistocene: a matter of ecological competition?

Increasing evidence suggests that the European human settlement is older than 1.2 Ma. However, there is a fierce debate about the continuity or discontinuity of the early human settlement of Europe. In particular, evidence of human presence in the interval 0.7-0.5 Ma is scarce in comparison with evidence for the previous and later periods. Here, we present a case study in which the environmental conditions at Sierra de Atapuerca in the early Middle Pleistocene, a period without evidence of human presence, are compared with the conditions in the previous period, for which a relatively intense human occupation is documented. With this objective in mind, the available resources for a human population and the intensity of competition between secondary consumers during the two periods are compared using a mathematical model. The Gran Dolina site TD8 level, dated to 0.7-0.6 Ma, is taken as representative of the period during which Atapuerca was apparently not occupied by humans. Conditions at TD8 are compared with those of the previous period, represented by the TD6-2 level, which has yielded abundant evidence of intense human occupation. The results show that survival opportunities for a hypothetical human population were lower at TD8 than they were at TD6-2. Increased resource competition between secondary consumers arises as a possible explanation for the absence of human occupation at Atapuerca in the early Middle Pleistocene.

The "bear" essentials: actualistic research on Ursus arctos arctos in the Spanish Pyrenees and its implications for paleontology and archaeology

Neotaphonomic studies of large carnivores are used to create models in order to explain the formation of terrestrial vertebrate fossil faunas. The research reported here adds to the growing body of knowledge on the taphonomic consequences of large carnivore behavior in temperate habitats and has important implications for paleontology and archaeology. Using photo- and videotrap data, we were able to describe the consumption of 17 ungulate carcasses by wild brown bears (Ursus arctos arctos) ranging the Spanish Pyrenees. Further, we analyzed the taphonomic impact of these feeding bouts on the bones recovered from those carcasses. The general sequence of consumption that we charted starts with separation of a carcass’s trunk; viscera are generally eaten first, followed by musculature of the humerus and femur. Long limb bones are not broken open for marrow extraction. Bears did not transport carcasses or carcass parts from points of feeding and did not disperse bones appreciably (if at all) from their anatomical positions. The general pattern of damage that resulted from bear feeding includes fracturing, peeling, crenulation, tooth pitting and scoring of axial and girdle elements and furrowing of the upper long limb bones. As predicted from observational data, the taphonomic consequences of bear feeding resemble those of other non-durophagus carnivores, such as felids, and are distinct from those of durophagus carnivores, such as hyenids. Our results have paleontological and archaeological relevance. Specifically, they may prove useful in building analogical models for interpreting the formation of fossil faunas for which bears are suspected bone accumulators and/or modifiers. More generally, our comparative statistical analyses draw precise quantitative distinctions between bone damage patterns imparted respectively by durophagus (modelled here primarily by spotted hyenas [Crocuta crocuta] and wolves [Canis lupus]) and non-durophagus (modelled here by brown bears and lions [Panthera leo]) carnivorans.

Using bones to shape stones: MIS 9 bone retouchers at both edges of the Mediterranean Sea

A significant challenge in Prehistory is to understand the mechanisms involved in the behavioural evolution of human groups. The degree of technological and cultural development of prehistoric groups is assessed mainly through stone tools. However, other elements can provide valuable information as well. This paper presents two bone retouchers dated to the Middle Pleistocene MIS 9 used for the shaping of lithic artefacts. Originating from Bolomor Cave (Spain) and Qesem Cave (Israel), these two bone retouchers are among the earliest of the Old World. Although the emergence of such tools might be found in the latest phases of the Acheulean, their widespread use seems to coincide with independently emergent post-Acheulean cultural complexes at both ends of the Mediterranean Sea: the post-Acheulean/pre-Mousterian of Western Europe and the Acheulo Yabrudian Cultural Complex of the Levant. Both entities seem to reflect convergent processes that may be viewed in a wider cultural context as reflecting new technology-related behavioural patterns as well as new perceptions in stone tool manufacturing.

Learning by heart: cultural patterns in the faunal processing sequence during the middle pleistocene

Social learning, as an information acquisition process, enables intergenerational transmission and the stabilisation of cultural forms, generating and sustaining behavioural traditions within human groups. Archaeologically, such social processes might become observable by identifying repetitions in the record that result from the execution of standardised actions. From a zooarchaeological perspective, the processing and consumption of carcasses may be used to identify these types of phenomena at the sites. To investigate this idea, several faunal assemblages from Bolomor Cave (Valencia, Spain, MIS 9-5e) and Gran Dolina TD10-1 (Burgos, Spain, MIS 9) were analysed. The data show that some butchery activities exhibit variability as a result of multiple conditioning factors and, therefore, the identification of cultural patterns through the resulting cut-marks presents additional difficulties. However, other activities, such as marrow removal by means of intentional breakage, seem to reflect standardised actions unrelated to the physical characteristics of the bones. The statistical tests we applied show no correlation between the less dense areas of the bones and the location of impacts. Comparison of our experimental series with the archaeological samples indicates a counter-intuitive selection of the preferred locus of impact, especially marked in the case of Bolomor IV. This fact supports the view that bone breakage was executed counter-intuitively and repetitively on specific sections because it may have been part of an acquired behavioural repertoire. These reiterations differ between levels and sites, suggesting the possible existence of cultural identities or behavioural predispositions dependant on groups. On this basis, the study of patterns could significantly contribute to the identification of occupational strategies and organisation of the hominids in a territory. In this study, we use faunal data in identifying the mechanics of intergenerational information transmission within Middle Pleistocene human communities and provide new ideas for the investigation of occupational dynamics from a zooarchaeological approach.

Selective Inhibition of Calcium Entry Induced by Benzylisoquinolines in Rat Smooth Muscle

The mechanism of relaxant activity of six benzylisoquinolines was examined in order to determine the minimal structural requirements that enable these compounds to have either a non-specific action like papaverine or an inhibitory activity on calcium entry via potential-operated channels. All the alkaloids tested totally or partially relaxed KCl-depolarized rat uterus and inhibited oxytocin-induced rhythmic contractions. Only glaucine and laudanosine inhibited K+-induced uterine contractions more than oxytocin-induced uterine contractions. In Ca+-free medium, sustained contractions induced by oxytocin or vanadate were relaxed by the alkaloids tested except for glaucine and laudanosine indicating no inhibitory effect on intracellular calcium release. Those alkaloids containing an unsaturated heterocyclic ring (papaverine, papaverinol, papaveraldine, N-methylpapaverine and dehydropapaverine) exhibited a more specific activity than those with a tetrahydroisoquinoline ring.

Alkaline cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Influence of pH

Water containing cyanide was biologically detoxified with the bacterial strain Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Volatilization of toxic hydrogen cyanide (HCN) was avoided by using an alkaline medium for the treatment. The operational procedure was optimized to assess cyanide biodegradation at variable pH values and dissolved oxygen concentrations. Using an initial pH of 10 without subsequent adjustment allowed total cyanide to be consumed at a mean rate of approximately 2.81 mg CN(-) L(-1) O.D.(-1) h(-1); however, these conditions posed a high risk of HCN formation. Cyanide consumption was found to be pH-dependent. Thus, no bacterial growth was observed with a controlled pH of 10; on the other hand, pH 9.5 allowed up to 2.31 mg CN(-) L(-1) O.D.(-1) h(-1) to be converted. The combination of a high pH and a low dissolved oxygen saturation (10%) minimized the release of HCN. This study contributes new basic knowledge about this biological treatment, which constitutes an effective alternative to available physico-chemical methods for the purification of wastewater containing cyanide or cyano-metal complexes.

Interactions between nitrate assimilation and 2,4-dinitrophenol cometabolism in Rhodobacter capsulatus E1F1

The phototrophic, nitrate-photoassimilating bacterium Rhodobacter capsulatus E1F1 cometabolizes 2,4-dinitrophenol (DNP) by photoreducing it to 2-amino-4-nitrophenol under anaerobic conditions. DNP uptake and nitrate metabolism share some biochemical features, and in this article we show that both processes are influenced by each other. Thus, as was demonstrated for nitrate assimilation, DNP uptake requires a thermolabile periplasmic component. Nitrate assimilation is inhibited by DNP, which probably affects the nitrite reduction step because neither nitrate reductase activity nor the transport of nitrate or nitrite is inhibited. On the other hand, DNP uptake is competitively inhibited by nitrate, probably at the transport level, because the nitroreductase activity is not inhibited in vitro by nitrate, nitrite, or ammonium. In addition, the decrease in the intracellular DNP concentration in the presence of nitrate probably inactivates the nitroreductase. These results allow prediction of a negative environmental effect if nitrate and DNP are released together to natural habitats, because it may lead to a lower rate of DNP metabolism and to nitrite accumulation.

Cyanide metabolism of Pseudomonas pseudoalcaligenes CECT5344: role of siderophores

Cyanide is one of the most potent and toxic chemicals produced by industry. The jewellery industry of Córdoba (Spain) generates a wastewater (residue) that contains free cyanide, as well as large amounts of cyano–metal complexes. Cyanide is highly toxic to living systems because it forms very stable complexes with transition metals that are essential for protein function. In spite of its extreme toxicity, some organisms have acquired mechanisms to avoid cyanide poisoning. The biological assimilation of cyanide needs the concurrence of three separate processes: (i) a cyanide-insensitive respiratory chain, (ii) a system for iron acquisition (siderophores) and (iii) a cyanide assimilation pathway. Siderophores are low-molecular-mass compounds (600–1500 Da) that scavenge iron (Fe3+) ions (usually with extremely high affinity) from the environment under iron-limiting conditions. There are two main classes of siderophores: catechol and hydroxamate types. The catechol-type siderophores chelate ferric ion via a hydroxy group, whereas the hydroxamate-type siderophores bind iron via a carbonyl group with the adjacent nitrogen. In the presence of cyanide, bacterial proliferation requires this specific metal uptake system because siderophores are able to break down cyano–metal complexes. Pseudomonas pseudoalcaligenes CECT5344 is able to use free cyanide or cyano–metal complexes as nitrogen source. A proteomic approach was used for the isolation and identification, in this strain, of a protein that was induced in the presence of cyanide, namely CN0, that is involved in siderophore biosynthesis in response to cyanide. An overview of bacterial cyanide degradation pathways and the involvement of siderophores in this process are presented.

Alkaline cyanide biodegradation by Pseudomonas pseudoalcaligenes CECT5344

Pseudomonas pseudoalcaligenes CECT5344 uses cyanide, cyanate, β-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile HCN (pKa 9.2) formation. The cyanide consumed by this strain is stoichiometrically converted into ammonium. In addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a siderophore-based mechanism for iron acquisition in the presence of cyanide. The detection of cyanase and β-cyanoalanine nitrilase activities in cyanide-induced cells suggests their implication in the cyanide degradation pathway.

[Descriptive study of behavioural disorders in mild cognitive impairment]

INTRODUCTION

Mild cognitive impairment (MCI) is defined as an abnormality in cognitive function not provoking a noticeable disability in activities of daily living in the affected person. In a group of patients with MCI, we propose to observe and to quantify the presence of behavioral disorders, using the neuropsychiatric inventory (NPI).

PATIENTS AND METHODS

NPI is a known instrument in evaluation of this kind of disorders in patients with dementia, and it is a semi structured interview with a relevant informer or relative to the patient. NPI was applied to a series of 100 cases (61 women and 39 men) of MCI, diagnosed as usual in our settings. Mean age was 74.3 +/- 10 years, and mean MEC (Spanish modified version of MMSE) 25.57 +/- 4.2 (over a maximum of 35 points).

RESULTS

Most prevalent disorder was depression, in 36 % of cases, and other frequent findings were irritability (35%), anxiety (24%) and apathy (19%). In some cases, agitation (4%), abnormal motor behavior (3%) and delusions (1%) were detected. Hallucination, disinhibition and euphoria or elation were not detected in this series.

CONCLUSION

Data show a certain similarity with occidental culture environment, globally considered. The presence of behavioral and psychological disorders in patients with MCI could be a marker for later development of dementia. NPI can be a usable tool when detection and evaluation of these symptoms is required.

[Animal sting and bites]

Under the heading of this subject we deal with stings by arthropods, making reference to the differences that exist between the stings of wasps and bees, commenting on the composition of the poisons and the different local and general reactions that are caused by such stings. Also discussed are the stings/bites caused by scorpions, spiders, ticks, and marine animals, with the clinical picture they provoke and the treatment that must be administered. Finally, snakebites are considered, with reference to the most frequent types of ophidia to be found in Navarra, how to differentiate between the bites of snakes and vipers, the different clinical pictures they provoke and the treatment to be applied

Flow-injection spectrophotometric determination of cyanate in bioremediation processes by use of immobilised inducible cyanase

A new flow injection (FI) method for photometric monitoring of cyanate in bioremediation processes using immobilised native cyanase is described. The method is based on the catalytic reaction between cyanate and bicarbonate to produce ammonia and carbon dioxide in the presence of an inducible native cyanase, immobilised in a reactor packed with glass beads. Two degrees of purification of the biocatalyst were used-heated cell-free extract and purified extract of cyanase from Pseudomonas pseudoalcaligenes CECT 5344. The ammonia produced by the enzymatic reaction is finally monitored photometrically at 700 nm using a modification of the conventional Berthelot method. The method furnishes different calibration curves depending on the degree of purification of the cyanase, with linear ranges between 1.23 and 616.50 micromol L(-1) ( r(2)=0.9979, n=7) and between 1.07 and 308.25 micro mol L(-1) ( r(2)= 0.9992, n=7) for the heated cell-free extract and the purified cyanase extract, respectively. No statistically significant differences between the samples were found in the precision study evaluated at two cyanate concentration levels using one-way analysis of variance. A sampling frequency of 15 h(-1) was achieved. The method was used to monitor cyanate consumption in a cyanate bioremediation tank inoculated with Pseudomonas pseudoalcaligenes CECT 5344 strain. The correlation between cyanate degradation and ammonia production was tested using a conventional method. Finally, the method was applied to different samples collected from the bioremediation tank using the standard addition method; recoveries between 85.9 and 97.4% were obtained.

Assimilation of D-malate by Rhodobacter capsulatus E1F1

Rhodobacter capsulatus grew by using either L- or D-malate as carbon sources under light/anaerobic conditions. The cellular yields were the same with D- or L-malate. Both L-malate dehydrogenase and L-malic enzyme activities were detected in cell-free extracts from cells grown in both isomers. By contrast, a racemase activity converting D-malate into L-malate was induced only when D-malate was present in the culture medium. This racemase activity was Mn2+-dependent and was measured by coupling it either to the malate dehydrogenase or to the fumarase activities. The racemase activity was partially purified by anion-exchange chromatography.

Bioremediation of an area contaminated by a fuel spill

In order to decontaminate a large area of restricted access contaminated by a fuel spill, laboratory and field studies were developed in two steps: (a) monitoring of the laboratory experiment on bacterial growth under aerobic and anaerobic conditions with and without addition of nutrients; and (b) use of the best conditions obtained in (a) for the decontamination of the soil. A hydraulic barrier was installed both to clean the aquifer and to avoid migration of hydrocarbons as a consequence of their solution in the groundwater and subsequent displacement. The objective was to create an ideal environment for the treatment of the affected area that favoured the growth of the indigenous bacteria (Pseudomonas and Arthrobacter) that biodegrade the hydrocarbons. Monitoring of the changes in the total concentration of petroleum hydrocarbons in the soil subjected to bacterial action was performed by gas chromatography. In a field study, the progress of biodegradation of hydrocarbons was evaluated in situ by changes in subsurface CO2/O2 levels by means of an analyser equipped with an infrared detector. Biostimulation and oxygen were the most influential factors for the biodegradation of the hydrocarbons. The use of bioventing of the soil was shown as an excellent technology to promote in situ bioremediation of the polluted area.

Rhodococcus sp. RB1 grows in the presence of high nitrate and nitrite concentrations and assimilates nitrate in moderately saline environments

Rhodococcus sp. RB1 was able to thrive in media with up to 0.9 M NaCl or KCl and in the presence of high concentrations of nitrate (up to 0.9 M) and nitrite (up to 60 mM), but only under oxic conditions. An adaptation period was not required for salt tolerance, but a rapid extrusion of K+ and intake of Na+ was observed after addition of 0.5 M NaCl. Nitrate assimilation was limited by the carbon supply, but nitrite was not accumulated in the culture medium, even at nitrate concentrations as high as 0.8 M, thus suggesting that nitrite reduction does not limit nitrate assimilation. The presence of NaCl or KCl did not affect nitrate or nitrite uptake, which were completely inhibited by ammonium or glutamine. Rhodococcus sp. RB1 nitrate reductase had an apparent molecular mass of 142 kDa and used NADH and reduced bromophenol blue or viologens as electron donors, independently of the presence of salt. The enzyme was associated with an NADH-diaphorase activity and was induced by nitrate and repressed by ammonium or glutamine, thus showing typical biochemical and regulatory properties of bacterial assimilatory NADH-nitrate reductases. The enzyme was active in vitro in the presence of 3 M NaCl or KCI, but the maximal activity was observed at 0.5 M salt. Addition of 2 M NaCl increased the optimal temperature of the enzyme from 12 to 32 degrees C, but the optimal pH (10.3) was unaffected.

Set of vectors for the expression of histidine-tagged proteins in vaccinia virus recombinants

Vaccinia virus expression vectors are widely used to direct the expression of proteins in eukaryotic cells. Here, we describe a new set of plasmid vectors designed for the expression of histidine-tagged proteins in the vaccinia system. To facilitate the rapid isolation of virus recombinants, the plasmids contain a viral gene (F13L) that serves as an efficient selection marker based on virus plaque phenotype. Histidine codons and restriction sites derived from pET-16b bacterial expression plasmid were included, thus facilitating the transfer of genes between E. coli and vaccinia expression plasmids. Plasmids in which the gene is placed downstream of either a strong vaccinia virus or a T7 promoter were constructed, allowing for constitutive or conditional expression, respectively, of the foreign protein.

Role for draTG and rnf genes in reduction of 2,4-dinitrophenol by Rhodobacter capsulatus

The phototrophic bacterium Rhodobacter capsulatus is able to reduce 2,4-dinitrophenol (DNP) to 2-amino-4-nitrophenol enzymatically and thus can grow in the presence of this uncoupler. DNP reduction was switched off by glutamine or ammonium, but this short-term regulation did not take place in a draTG deletion mutant. Nevertheless, the target of DraTG does not seem to be the nitrophenol reductase itself since the ammonium shock did not inactivate the enzyme. In addition to this short-term regulation, ammonium or glutamine repressed the DNP reduction system. Mutants of R. capsulatus affected in ntrC or rpoN exhibited a 10-fold decrease in nitroreductase activity in vitro but almost no DNP activity in vivo. In addition, mutants affected in rnfA or rnfC, which are also under NtrC control and encode components involved in electron transfer to nitrogenase, were unable to metabolize DNP. These results indicate that NtrC regulates dinitrophenol reduction in R. capsulatus, either directly or indirectly, by controlling expression of the Rnf proteins. Therefore, the Rnf complex seems to supply electrons for both nitrogen fixation and DNP reduction.

Intracellular localization of vaccinia virus extracellular enveloped virus envelope proteins individually expressed using a Semliki Forest virus replicon

The extracellular enveloped virus (EEV) form of vaccinia virus is bound by an envelope which is acquired by wrapping of intracellular virus particles with cytoplasmic vesicles containing trans-Golgi network markers. Six virus-encoded proteins have been reported as components of the EEV envelope. Of these, four proteins (A33R, A34R, A56R, and B5R) are glycoproteins, one (A36R) is a nonglycosylated transmembrane protein, and one (F13L) is a palmitylated peripheral membrane protein. During infection, these proteins localize to the Golgi complex, where they are incorporated into infectious virus that is then transported and released into the extracellular medium. We have investigated the fates of these proteins after expressing them individually in the absence of vaccinia infection, using a Semliki Forest virus expression system. Significant amounts of proteins A33R and A56R efficiently reached the cell surface, suggesting that they do not contain retention signals for intracellular compartments. In contrast, proteins A34R and F13L were retained intracellularly but showed distributions different from that of the normal infection. Protein A36R was partially retained intracellularly, decorating both the Golgi complex and structures associated with actin fibers. A36R was also transported to the plasma membrane, where it accumulated at the tips of cell projections. Protein B5R was efficiently targeted to the Golgi region. A green fluorescent protein fusion with the last 42 C-terminal amino acids of B5R was sufficient to target the chimeric protein to the Golgi region. However, B5R-deficient vaccinia virus showed a normal localization pattern for other EEV envelope proteins. These results point to the transmembrane or cytosolic domain of B5R protein as one, but not the only, determinant of the retention of EEV proteins in the wrapping compartment.

Puromycin resistance (pac) gene as a selectable marker in vaccinia virus

The antibiotic puromycin, an inhibitor of protein synthesis, was shown to inhibit vaccinia virus (VV) replication. We evaluated the use of puromycin-resistance (pac) gene as a selectable marker in VV. A recombinant vaccinia virus expressing pac (VV-pac) under the control of a viral early/late promoter was constructed and characterized. VV-pac grew in the presence of puromycin at concentrations that were inhibitory for the parental VV and toxic for the cells. Isolation of recombinant VV usually relies on plaque purification under selective conditions. Because virus plaquing was not feasible under inhibitory puromycin concentration, a protocol based on serial passage of virus was devised. The usefulness of this procedure in selecting pac expressing viruses was tested by isolating a recombinant VV.

Sequence and analysis of a swinepox virus homologue of the vaccinia virus major envelope protein P37 (F13L)

P37 (F13L gene product), the most abundant protein in the envelope of the extracellular virus form of the prototype poxvirus, vaccinia virus (VV), is a crucial player in the process leading to acquisition of the envelope, virus egress and transmission. We have cloned and sequenced a swinepox virus (SPV) gene homologous to VV F13L. The SPV gene product, termed P42, was 54% identical to P37, the VV F13L gene product, and, among the poxviruses, was most similar (73% identity) to the myxoma virus homologue. The SPV P42 gene contained late transcription signals and was expressed only at late times during infection. The protein was palmitylated, and showed an intracellular distribution similar to that of VV P37, both by immunofluorescence and by subcellular fractionation. As with VV P37, SPV P42 was incorporated in extracellular enveloped SPV particles, but was absent from the intracellular mature virus form. To check the ability of SPV P42 to function in the context of VV infection, we inserted the SPV gene into a VV deficient in P37, which is severely blocked in virus envelopment and cell-to-cell transmission. Despite correct expression of SPV P42, the resulting recombinant VV showed no rescue of extracellular virus formation or cell-to-cell virus spread. The lack of function of SPV P42 in the VV genetic background suggests that specific interactions between SPV P42 or VV P37 and other viral proteins is required to drive the envelopment process.

Role of mast cells in the pathogenesis of postburn inflammatory response: reactive oxygen species as mast cell stimulators

Thermal trauma has a direct effect on mast cells, triggering the secretion of histamine. This secretion leads to an enhanced xanthine oxidase activity and an increased production of reactive oxygen species (ROS), the latter being produced after burns through differing mechanisms. As ROS have been shown to have deleterious effects on cellular membranes, a lesion of the mast cell membrane could close the circle of autoinjury due to the vasoactive actions of mast cell mediators. Our studies were designed to assess the potentiality of ROS as stimulators of mast cell degranulation after burns by comparing two groups of rats treated, respectively, with SOD and saline solution after a scald injury. Plasma levels of tryptase and histamine were analyzed as markers of mast cell activity. A comparison of the mean increases of tryptase between baseline and 3-h postburn levels in the two groups shows significant differences (p < 0.001) (control: 0.13+/-0.04, SOD: 0.03+/-0.01). When comparing the mean increases between the baseline and 3 h postburn levels of histamine in the two groups, significant differences were also found (p < 0.001) (control group: 2.70+/-0.57. SOD group: 1.22+/-0.32). The lower levels of histamine and tryptase induced by SOD provides indirect evidence that ROS are involved in the process, causing the release of such mediators by mast cells, which may in turn suggest that ROS can act as stimulators of mast cell degranulation in burns.

Horizontal transmissible protection against myxomatosis and rabbit hemorrhagic disease by using a recombinant myxoma virus

We have developed a new strategy for immunization of wild rabbit populations against myxomatosis and rabbit hemorrhagic disease (RHD) that uses recombinant viruses based on a naturally attenuated field strain of myxoma virus (MV). The recombinant viruses expressed the RHDV major capsid protein (VP60) including a linear epitope tag from the transmissible gastroenteritis virus (TGEV) nucleoprotein. Following inoculation, the recombinant viruses induced specific antibody responses against MV, RHDV, and the TGEV tag. Immunization of wild rabbits by the subcutaneous and oral routes conferred protection against virulent RHDV and MV challenges. The recombinant viruses showed a limited horizontal transmission capacity, either by direct contact or in a flea-mediated process, promoting immunization of contact uninoculated animals.

Interaction of Sphingomonas and Pseudomonas strains in the degradation of chlorinated dibenzofurans

We have studied the concerted degradation of two monochlorodibenzofurans by a bacterial consortium, consisting of the chlorodibenzofurans-cometabolizing and chlorosalicylates-excreting strain Sphingomonas sp RW16, and Pseudomonas sp RW10, which mineralized the released chlorosalicylates. Neither of the organisms was able to grow with chlorodibenzofurans alone. Degradation of 2-chloro- and 3-chlorodibenzofuran proceeded to the end products 5-chloro- and 4-chlorosalicylate, respectively, when the initial dioxygenase of Sphingomonas sp RW 16 attacked the unchlorinated aromatic ring of the heterocyclic dibenzofuran molecule. 2-Hydroxypenta-2,4-dienoate, formed upon meta-cleavage of the intermediary chlorotrihydroxybiphenyls, served as a growth substrate for the sphingomonad. Presumably, most of the chlorosalicylates were excreted and degraded further by Pseudomonas sp RW10. Mineralization of both chlorosalicylates proceeded through a converging pathway, via 4-chlorocatechol, and protoanemonin. Chlorosalicylates were mineralized by the pseudomonad only when their concentration in the culture medium was below 1.5 mM. In the case of initial dioxygenation taking place on the chlorinated aromatic ring, salicylate and chlorinated hydroxypentadienoates should be formed. The metabolic fate of putative chlorohydroxypentadienoates is not clear; ie, they may be channeled into unproductive catabolism and, thus, represent the critical point in the breakdown of the carbon of these two chlorodibenzofurans by Sphingomonas sp RW16.