Shelter Walls Research Articles

LOADS ON SUBMERGED WALLS OF PROTECTIVE STRUCTURES

The intensification of military operations on the territory of Ukraine, which are accompanied by missile attacks and bombing of territories, requires the use of reliable protective structures. Modern codes require the provision of each new building with storage facilities that guarantee the safety of life and health of citizens, so the correct determination of all loads on the structural elements of protective structures is an urgent issue. Taking into acoount the fact that the previous codes were somewhat outdated and had limited access for a long time, a significant event was the adoption in 2023 of new codes for the design of protective structures of civil defence. The main requirements and recommendations of SBC B.2.2-5:20023 were taken into account when conducting research on determining the loads on buried walls of bomb shelters. Such structures, as we know, perceive a constant load from the lateral pressure of the soil, which during an explosion is supplemented by an episodic load from the action of an air wave. Modern specialized literature contains rather limited information on scientific research and development in the field of design of protective structures. An actual issue is also the study of the influence of determining factors on the intensity of the load on the walls of buried protective structures and the possibility of its adjustment in order to reduce it. Taking into account the nature of the distribution of loads on the underground walls of bomb shelters, a dependence was obtained to determine the resulting active pressure and quasi-static load caused by the action of an air wave. The pressures from the soil and the blast wave at different orientations of the contact wall and for different types of soil environment were studied. The loads in contact of a smooth and rough wall with sandy, sandy and loamy soils with different indicators of physical and mechanical characteristics were considered. The obtained results indicate a significant influence of the geometric parameters of the wall and the features of the contact soil on the resulting pressure, which can vary depending on the studied factors by 10-20%, which indicates the possibility of reducing the load on protective structures, operating with the considered indicators.

Practical Approach to Nuclear Shelter Wall Thickness Estimation

Abstract In the complex situation in which we live, preventive measures are increasingly being taken against the threat of nuclear attack and ionizing radiation, nuclear shelters are being built for private and public purposes. The purpose of the authors is to provide a practical approach to quickly calculate the thickness of the concrete shelter wall for such cases. The shelter wall thickness is assessed on the basis of published data on radiation dose calculations, corroborated by field data from nuclear tests, and information or calculations of the dose attenuation in the shelter wall. Doses from nuclear tests or simulations are summarized in tables in relation to bomb yield and distance from the explosion point. A dose criterion is chosen as the acceptable dose behind the shield. Neutron dose transmission factors, defined as ratio of the dose criterion to the dose without shielding are calculated. The concrete wall thickness corresponding to the neutron dose transmission factor was taken from reference sources. For gamma rays, the shield thickness is calculated based on an analytical relationship between dose without shield, the dose criterion, and the shield thickness. Data tables are provided with the estimated concrete wall thickness in relation to bomb yield and distance.

Structural and Geomechanical Analysis of Natural Caves and Rock Shelters: Comparison between Manual and Remote Sensing Discontinuity Data Gathering

The stability of many shallow caves and rock shelters relies heavily on understanding rock discontinuities, such as stratification, faults, and joints. Analyzing these discontinuities and determining their orientations and dispersion are crucial for assessing the overall stability of the cave or shelter. Traditionally, this analysis has been conducted manually using a compass with a clinometer, but it has certain limitations, as only fractures located in accessible areas like the lower part of cave walls and entrances are visible and can be assessed. Over the past decade, remote sensing techniques like LiDAR and photogrammetry have gained popularity in characterizing rocky massifs. These techniques provide 3D point clouds and high-resolution images of the cave or shelter walls and ceilings. With these data, it becomes possible to perform a three-dimensional reconstruction of the cavity and obtain important parameters of the discontinuities, such as orientation, spacing, persistence, or roughness. This paper presents a comparison between the geomechanical data obtained using the traditional manual procedures (compass readings in accessible zones) and a photogrammetric technique called Structure from Motion (SfM). The study was conducted in two caves, namely, the Reguerillo Cave (Madrid) and the Cova dos Mouros (Lugo), along with two rock shelters named Abrigo de San Lázaro and Abrigo del Molino (Segovia). The results of the study demonstrate an excellent correlation between the geomechanical parameters obtained from both methods. Indeed, the combination of traditional manual techniques and photogrammetry (SfM) offers significant advantages in developing a more comprehensive and realistic discontinuity census.

A Comparison of Reinforcement Planning for Basement Wall Shelter Based on SS EN 1990: 2008 (2015) with Technical Requirements for Household Shelter 2023

Singapore is an example that applies the concept of household housing, namely buildings that are used as evacuation places. One of the buildings that applies the household residential concept is a detached type of residential house with a basement located at 102 Jalan Langgar Bedok, Bedok Planning Area, Singapore in an HDB housing block. The technical guidebook used as a guideline for building household shelters is "2023 Household Shelter Technical Requirements". The aim of this research is to compare household reinforcement shelter planning based on SS EN 1990: 2008 (2015) with the 2023 Household Shelter Technical Requirements. The method used in this research is a quantitative method using secondary data, namely the dimensions of the household shelter building and the results on-site survey. The results of this research show that when planning reinforcement using SS EN 1990: 2008 (2015), the diameter of the reinforcement used is larger, namely H16-100, compared to the 2023 Household Shelter Technical Requirements guidebook, namely H10-100. This is because the walls of household shelters are also used as basement walls.

Limiting Exposure to Scattered Radiation From a CT System Installed ina Two-Sided Deployable ISO-Shelter.

Diagnostic radiology in the deployed military environment (in-theater diagnostic radiology) was greatly improved in the early 1990s with the addition of CT systems installed in military-grade one-sided expandable ISO-shelters. These shelters were provided with limited radiation shielding by several flexible lead curtains covering only a small portion of the shelter walls, necessitating placement of deployed CT systems at substantial distances from the field medical facility to limit exposures to personnel from secondary radiation. The newest generation deployable CT system is housed in a two-sided ISO-shelter with radiation shielding applied to the shelter walls. To ensure compliance with military and national standards for protection against ionizing radiation, we developed a simple method to calculate safe distances based on workload, frequencies of the various CT exams performed, and occupancy of controlled and uncontrolled areas. Calculation of radiation air kerma rates outside a two-sided CT ISO-shelter was developed using guidance from the National Council on Radiation Protection and Measurements Report No. 147. The simplified formula included measured radiation transmission factors for the ISO-shelter wall and installed shielding, occupancy factors, fraction of all CT exams that covered the chest, abdomen, and/or pelvis, total number of CT exams per week, and shielding design goals for controlled and uncontrolled areas. The formula was modified subsequently to account for whole-body CT exams expected during armed conflict. Calculated safe distances revealed that the shielded two-sided CT ISO-shelter can be positioned much closer to the surgical shelters of the field medical unit than the previously unshielded one-sided CT ISO-shelter. Tables of safe distances for controlled and uncontrolled areas for the two medical support environments of disaster relief/peacekeeping and combat are provided. For example, for a controlled area at 100% occupancy when 300 CT exams per week are performed and 50% of those exams are of the chest, abdomen, and/or pelvis, the safe distance between the nearest surgical shelter and the shielded CT ISO-shelter is 2.1m. By comparison, the safe distance for an unshielded CT ISO-shelter is 8.5 m under the same conditions. For lower occupancy factors and lower weekly workload, safe distances from the nearest surgical shelter are often negligible. The shielding in the new deployable CT ISO-shelter substantially reduces the distance between it and the surgical shelters of the field medical unit necessary to ensure radiation safety. Safe distances depend on several factors including workload, types and frequencies of CT exams, occupancy factors, and classification of the area around the ISO-shelter, i.e., controlled and uncontrolled.

Performance of Base-Isolated RC School Building under Blast Loading

It is known that bomb-laden vehicles target many buildings as a result of terrorist activities. The effects of such attacks must be reduced and structures must be protected against blast effects. In high seismic hazard regions, buildings are designed to be earthquake resistant. One of the methods used to dampen earthquake effects on structures is base isolation. Base isolation is effective in distributing blast loads to the structure, similar to seismic loading. In this study, the effects of this distribution on the structure will be evaluated. The scope of the study encompasses the numerical estimation of explosive loads at different distances according to the explosive material carrying capacity of various vehicles and their effects on structures. Linear and nonlinear analysis methods were used to compare the dynamic behaviour of school buildings designed with and without base isolators. The Turkish Building Earthquake Code (2018), which includes the maximum seismic loads, was used in the design of the isolators. Numerical analysis was performed using SAP2000 software based on the finite element method. The blast loads were applied to the floors of the building using the direct integration method in the time domain. FEMA standards were used to determine the blast loads and the performance was evaluated in comparison with the numerical analysis results. As a result of the study, it was concluded that structures with base isolators are efficient in reducing the effects of an explosion at certain distances and these distances will affect the design of the shelter walls.

Characteristics of saferoom/shelter wall structures—a state-of-the-art review

ABSTRACT There are several ongoing humanitarian crises all around the world that have led to many refugees, who need affordable shelters and saferooms. Additionally, these structures are widely located in the backyard of homes in case of hurricanes, tornados, and/or earthquakes. This paper presents a chronological literature review of investigations and comparisons on characteristics of different type of saferoom/shelter wall systems. The characteristics, scrutinized in this study for each type of wall, include structural strength, construction cost, time to construct, and sustainability of saferoom/shelter walls. The most significant contributions of these studies are identified and presented. The results showed that soilbag shelter walls can be constructed with relatively low cost, relatively shorter time, and being relatively more sustainable compared to other types of shelter walls considered in this study. Soil-filled earthbag specimens are stronger and stiffer than gravel-filled specimens of identical size and stack geometry. Using locally available materials minimizes the energy needed and pollution produced due to material transportations. Furthermore, recyclable waste bags can be used to produce bags in soilbags. A slanted roof can be used in any type of shelter wall to harvest rainwater for each shelter use. Moreover, the literature review indicated that the shelter walls made of CLT, and lumber panels are generally stronger against wind loads (250-mph) compared to walls made of soilbags (225-mph).

Bushfire-Resistant Lightweight Masonry Blocks with Expanded Perlite Aggregate

During bushfires, one of the building elements that is directly exposed to embers, radiant heat and direct flames is the “wall” element. This study investigated the feasibility of using expanded perlite aggregate in masonry (i.e., cement) blocks to enhance their bushfire resistant characteristics. The chemical, physical, and thermal properties of expanded perlite aggregate were determined first and then masonry block cement mixes were developed by replacing sand in the conventional mix with expanded perlite aggregate by volume at different percentages (100, 80, 60, and 40%). The properties of fresh and hardened cement mixes (slump, density, compressive strength, and water absorption) were measured. The developed masonry blocks were exposed to Bushfire Flame Zone conditions (i.e., 20–842 °C) and the standard fire curve for three hours (i.e., 20–1110 °C) to assess their resistance to bushfires and building fires, respectively. The properties of Cement–Expanded Perlite mixes were compared with those of the standard Cement–Sand mix. The test results showed that the use of perlite aggregate reduced the workability, density, and compressive strength of the cement mix while increasing the water absorption and fire resistance level. All the developed perlite blocks were lightweight and had three hours of fire resistance level (-/180/180). When exposed to bushfire flame zone conditions, the blocks made with 100, 80, and 60% perlite satisfied the maximum ambient surface temperature limit. Of these, masonry blocks made with 60% perlite aggregate are the most suitable for use in external walls of bushfire shelters and residential and commercial buildings in bushfire-prone areas.

Marra Wonga: Archaeological and contemporary First Nations interpretations of one of central Queensland’s largest rock art sites

A large sandstone rock art site, Marra Wonga, near Barcaldine, central Queensland, is the focus of this paper. This 160-metre-long rock shelter is estimated to have over 15,000 petroglyphs, which are mostly animal tracks, lines, grooves and drilled holes, as well as 111 hand-related and object stencils. There is also a cluster of human-shaped foot petroglyphs on the floor of the shelter, some with six or more toes. Unique compositions on the shelter wall include seven large, engraved star-like designs with central engraved pits and large, engraved snake-like designs running across and through other petroglyphs. We describe and discuss some of the features of Marra Wonga from archaeological (etic) and ethnographic (emic) perspectives, especially in terms of the significance of a petroglyph of an anthropomorph, seven star-like designs seemingly made as part of a composition, the large snake-like designs, and six-toed human feet. Today, Marra Wonga is a teaching site used to tell important cultural stories that are connected to many other places through the imagery and Dreaming Tracks, as well as a tourist destination managed by the Yambangku Aboriginal Cultural Heritage and Tourism Development Aboriginal Corporation (YACHATDAC), with whom we partnered for this research.

Colonisation and early peopling of the Colombian Amazon during the Late Pleistocene and the Early Holocene: New evidence from La Serranía La Lindosa

Recent research carried out in the Serranía La Lindosa (Department of Guaviare) provides archaeological evidence of the colonisation of the northwest Colombian Amazon during the Late Pleistocene. Preliminary excavations were conducted at Cerro Azul, Limoncillos and Cerro Montoya archaeological sites in Guaviare Department, Colombia. Contemporary dates at the three separate rock shelters establish initial colonisation of the region between ~12,600 and ~11,800 cal BP. The contexts also yielded thousands of remains of fauna, flora, lithic artefacts and mineral pigments, associated with extensive and spectacular rock pictographs that adorn the rock shelter walls. This article presents the first data from the region, dating the timing of colonisation, describing subsistence strategies, and examines human adaptation to these transitioning landscapes. The results increase our understanding of the global expansion of human populations, enabling assessment of key interactions between people and the environment that appear to have lasting repercussions for one of the most important and biologically diverse ecosystems in the world.

Subsidiary adaptations: climbing techniques in vespertilionid bats

The quadrupedal locomotion of bats still remains almost unexplored. Meanwhile, in the life of many species, this type of movement plays an important role. This paper presents the study of characteristics of quadrupedal locomotion on vertical surfaces in bats. We provide the results of the analysis of climbing of five vespertilionid species. The study is based on high-speed video recording of locomotion in two planes in an experimental enclosure on various substrates (the bark of five tree species and the inner surface of the manufactured nest box for bats). For comparison, we used data on horizontal locomotion obtained using the same experimental facilities, as well as all available literature data to date. The time, metric and velocity characteristics of the movement of different species representatives are determined. We show how these characteristics are interrelated and how they differ in walking or climbing. The study comparing walking vs. climbing was performed for the second time ever. It is shown that while climbing, bats retain the same limb sequence, but the gait is not a slow trot-like walk but a very slow walk. There are considerably fewer deviations from the usual symmetrical sequence gait (wherein a forelimb movement is followed by that of the contralateral hind limb) when climbing than when walking, and they are all associated with the search for support. Our results show that not all tree-dwelling species of vesper bats can move up the trees which they use to roost. The surface of the inner walls of artificial shelters for bats may be a significant factor in their occupancy. While designing such shelters, it is advisable to consider the results of our experiments or conduct tests on the behavior of particular species on specific artificial surfaces.

From rock art to contemporary art: Indigenous depictions of trains, planes and automobiles

A number of recent studies have shown that ships are a common subject of contact period rock art in Australia and some other countries. More generally, one of the most common themes in most bodies of contact rock art is that of transport. Besides introduced watercraft, trains, planes and automobiles were painted, engraved and drawn at many rock art sites. Occasionally, bicycles, buggies, motorcycles and rickshaws were also depicted. Horses are common in many parts of the world, especially at sites inland and far from the coast, but occasionally elephants with mahoots, camels and other beasts of transport were emblazoned on rock shelter walls and ceilings. This paper focuses on examples of transport rock art from Australia, Malaysia and South Africa in particular but is relevant to contact rock art world-wide. One of the conclusions is that Indigenous peoples were just as interested in what brought new peoples to their lands as they were in the new arrivals themselves.

Neanderthal activity and resting areas from stratigraphic unit 13 at the Middle Palaeolithic site of Oscurusciuto (Ginosa - Taranto, Southern Italy)

Stratigraphic Unit 13 of Oscurusciuto Rockshelter (Ginosa, Taranto, Southern Italy) is a short Mousterian palimpsest representing the first stable occupation of the site soon after the deposition of a thick layer of tephra (Mt. Epomeo Green Tuff - Ischia datable around 55 kya BP).Different activities were identified by integrating the study of lithic finds, faunal remains, and the microarchaeology of combustion features. Additionally, geo-statistical analysis of these data has been carried out using a specifically designed geodatabase within a GIS platform.Our results produced an articulated picture of this Neanderthal site as a tripartite location made of spatially segregated and integrated activity areas. A hearths' alignment (parallel to the rockshelter wall) divides the settled area into an inner and outer part. The inner part, between the hearths and the shelter wall, displays an abrupt rarefaction of the anthropic finds and was interpreted as a possible sleeping/resting area. In the outer part, several multipurpose activity areas have been identified, mostly associated with the combustion features. The Northern sector of the settlement appears devoted particularly to lithic production (to a lesser degree, activities related with lithic tools use and faunal processing took place). In the Southern sector the main activities carried out represent more intensive production and use of lithic tools and the butchering and consumption of animal resources. Additionally, in this sector evidence of space maintenance behaviour (cleaning up of working areas and refuse dumping) has been attested.

Micro-Raman spectroscopy of rock paintings from the Galb Budarga and Tuama Budarga rock shelters, Western Sahara

Rock paintings of two recent discovered rock shelters, Galb Budarga and Tuama Budarga, from the southeastern area of the Western Sahara, Sahrawi Arab Democratic Republic, have been studied by micro-Raman spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray spectrometry in order to characterize the composition of the materials present in the painting panels. An unusual white pigment has been used in the zoomorphic pictographs of the Galb Budarga shelter which main components are the anhydrite (CaSO4) polymorphs I and II. Red and orange zoomorphic figures and ancient Berber scripts have been painted in the Tuama Budarga rock shelter. Haematite (α-Fe2O3) is the main component of the paints used; amorphous carbon and different manganese oxides have also been detected. Accretions of gypsum (CaSO4·2H2O) and anhydrite have been observed on the shelter wall used to paint. α-Quartz (α-SiO2), albite (NaAlSi3O8), dolomite, CaMg(CO3)2, calcite (CaCO3) and traces of hydroxylapatite (Ca10(PO4)6(OH)2) have been identified in the rocks supporting the paintings of both sites. Layers of calcium oxalates, whewellite (CaC2O4·H2O) and weddellite (CaC2O4·(2+x)H2O, x≤0.5) cover the pictorial panels of these rock shelters. A microestratrigraphic study of the paint used in the Tuama Budarga shelter revealed that the pigment layer is bracketed between oxalate layers.

Plants before farming: The deep history of plant-use and representation in the rock art of Australia's Kimberley region

The orthodox notion of agriculture cumulatively and inevitably developing from foragers' gathering practices is increasingly untenable. Recent archaeological, botanical and genetic research from Asia and Australia show precocious manipulation of plant resources that continue for millennia within a forager ideology and practice without culminating in ‘agriculture’. Australia's Kimberley is an especially productive research region with a wide range of environmental niches on a topographically varied landscape that has had human settlement spanning over the last 50,000 years. Previously characterised as ‘foragers’ until contact with travellers from Indonesia and then Europeans over the last few hundred years; new research questions this simplistic characterisation of Aboriginal people, and suggests instead a particularly complex and enduring set of people-plant relationships. This complexity is given material witness in the form of Kimberley rock art, which stands out globally in having an enormous body of direct and indirect depictions of plants, including: grasses, trees, tubers; pigment-soaked plants imprinted on rock shelter walls; anthropomorphism of plants; and plant-based material culture such as digging sticks, dilly bags, and wood-hafted stone axe. These are more than simple illustrations of a forager economic base. Instead, rock art is a primary record of long-term sophisticated physical and symbolic manipulation of plants that fits neither into the simplistic categories of ‘foraging’ or of ‘agriculture’. Rather, we have a society in which people actively chose not to pursue orthodox agriculture while according plants a central place in their lives.

SILKS AND SILK-PRODUCING ORGANS OF NEOTROPICAL TARANTULA AVICULARIA METALLICA (ARANEAE, MYGALOMORPHAE, THERAPHOSIDAE)

Silks and silk-producing organs of the theraphosid species Avicularia metallica were studied using scanning electron microscopy. The spinning apparatus is made up of two pairs of spinnerets located at the end of the ventral side of the opisthosoma. Both pairs of spinnerets are equipped with spigots (modified setae), i.e. external outlets of silk-producing glands which, in the case of posterior lateral spinnerets, are present on all three segments.The secreted silk, which hardens when exposed to air, is processed by movements of spinnerets and the opisthosoma. An investigation of spinning activity revealed two different manners in which silk is affixed to the ground: (1) by smearing silk secretion directly onto the surface of the substratum; or (2) by attaching silken fibers onto a layer of adhesive silk of attachment fields. The fibers connecting the walls of tubular shelters to the silk of attachment fields are essentially bundles of parallel nanofibrils. The connection between multifibrillar connecting fibers and the adhesive silk of attachment fields is, in essence, “silk-to-silk” connection. Nanoglobules (spherical subunits) are the basic microstructural blocks in the studied silk materials irrespective of whether the fibrils are a part of the tube, connecting fibers, or attachment fields. SEM images showed that the liquid silk, running through spigot ducts, has two components, which do not mix as they leave the spigots. The peripheral component of the solidified protein mixture surrounds the central component, which has a granular appearance

The social dimension of human depiction in Magdalenian rock art (16,500 cal. BP–12,000 cal. BP): The case of the Roc-aux-Sorciers rock-shelter

The rock shelter of Le Roc-aux-Sorciers is one of the major Upper Palaeolithic sites of Europe, along with the caves of Chauvet and Lascaux. At the foot of the cliff of Le Roc-aux-Sorciers, from the 1930s onwards, the research carried out by Lucien Rousseau (1927–1933), S. de Saint-Mathurin (between 1947 and 1990), and then by G. Pincon (since 1993) has led to a better understanding of this place that was occupied by hunter-gatherers 15,000 years ago. This is a rare example of an archaeological site that features a rich regular occupation (between 15,000 BP and 14,000 BP) attributed to the Middle Magdalenian associated with monumental parietal art. The sculpted frieze, an exceptional testimony to the artistic mastery of these peoples, contains – over a distance of almost 20 m – more than thirty animal and human depictions. The human figures, which are very prominent in this parietal art, make this place even more remarkable. The humans depicted on the shelter's wall and ceiling enable us to discuss these people's thought processes. The images pose the question of how these hunter-gatherers conceived the body, as well as the constructions of identity that may stem from that. In this article I propose to present a synthesis of the human depictions of Le Roc-aux-Sorciers and to analyse the role of these images in the occupation of the territory, and the inscription of the human groups in the landscape. It appears that, in the mechanisms of otherness of the ethnic groups of the Upper Palaeolithic, human depictions played an important role in the expression of identities.

The Middle Pleistocene site of La Cansaladeta (Tarragona, Spain): Stratigraphic and archaeological succession

La Cansaladeta is a site located in a narrow passage dug out by the Francolí River in the Pre-littoral Catalan range (NE Iberia). The archaeological deposit lies on top of a +45–50 m fluvial terrace, and contains a rich Middle Pleistocene stratigraphic succession in which 10 archaeological layers have been identified.Here, we present the description of the sedimentary succession of the site, the available chronological framework (including TL, TT-OSL, and ESR/U series ages, as well as biostratigraphical information), the characteristics of the lithotechnical and faunal assemblages, as well as the first interpretation of the human occupations at the site.Three main occupation phases have been differentiated. The oldest archaeological layers are embedded in a palaeosol formed on a clayey layer that contains limestone fragments detached from the shelter's wall and roof. During the second phase, low energy fluvial sediments coming from lateral river floods were deposited and sealed the archaeological layers. After a transitional phase, the upper layers appear to be derived from slope sediments. Numerical dating yielded internally consistent dates of 380–400 ka for the sequence. However, the study of the fossil assemblages potentially suggest a tentative early Middle Pleistocene age for the lowermost horizons.The rich technological record is made up of several local raw materials, especially chert but also schist, quartzite, quartz and other minor rocks. Knapping sequences seem to be autochthonous, as all the elements and size-categories of the reduction sequence are present, and refits are common. Techno-typological features observed along the sequence are not very diagnostic, however the lower layers include some Acheulean forms among the large shaped tools, restricted variability among the small retouched tools (mostly denticulates) and a virtually absence of prepared cores. The faunal assemblage is scarce and appears strongly altered. Only the lower layers have provided fruitful information. Although neither combustion areas nor structures related to fire-use have been documented to date, heat damage has been repeatedly recorded on both lithic and faunal remains. This may point to systematic fire use within the archaeological sequence.The data provided by the ongoing excavations at La Cansaladeta provide new insight into the early human settlement history of northeast Iberia to be reconstructed. Combining these data with those coming from the close site of Barranc de la Boella, enable us to better reconstruct the timing, nature and context of early human occupation in the region.

Spatial and temporal distributions of the Spinose Ear Tick,Otobius megnini, within animal shelters at Fossil Rim Wildlife Center

Spinose ear ticks, Otobius megnini, are monoxenous parasites that feed within the ear of ungulates, subjecting them to debilitating conditions. Little is known about the spatial dispersion of spinose ticks in animal shelters or the temporal variation in their abundance. Therefore, the objectives of this study were to: 1) determine the temporal distribution of spinose ear tick abundance within animal shelters, 2) determine the spatial distribution of larvae and adults within animal shelters, and 3) examine the effects of climatic variables on tick abundance. No temporal trend was identified for larval or adult ticks. Larval abundance was highest in quadrats located against the shelter wall while no spatial difference was found in adult abundance. Mean larval tick abundance was significantly correlated with mean temperature while mean adult tick abundance was significantly correlated with mean relative humidity.

Nouvelles recherches sur l’identité culturelle et stylistique de la grotte Chauvet et sur sa datation par la méthode du 14C

The discovery of Chauvet cave, at Vallon-Pont-d’Arc (Ardèche), in 1994, was an important event for our knowledge of palaeolithic parietal art as a whole. Its painted and engraved figures, thanks to their number (425 graphic units), and their excellent state of preservation, provide a documentary thesaurus comparable to that of the greatest sites known, and far beyond what had already been found in the group of Rhône valley caves (Ardèche and Gard). But its study – when one places it in its natural regional, cultural and thematic framework – makes it impossible to see it as an isolated entity of astonishing precocity. This needs to be reconsidered, and the affinities that our research has brought to light are clearly incompatible with the very early age which has been attributed to it. And if one extends this examination to the whole of the Franco-Cantabrian domain, the conclusion is inescapable: although Chauvet cave displays some unique characteristics (like every decorated cave), it belongs to an evolved phase of parietal art that is far removed from the motifs of its origins (known from art on blocks and on shelter walls dated by stratigraphy to the Aurignacian, in France and Cantabrian Spain). The majority of its works are therefore to be placed, quite normally, within the framework of the well-defined artistic creations of the Gravettian and Solutrean. Moreover, this phase of the Middle Upper Palaeolithic (26,000–18,000) coincides with a particularly intensive and diversified local human occupation, unknown in earlier periods and far less dense afterwards in the Magdalenian. A detailed critique of the treatment of the samples subjected to AMS radiocarbon dating makes it impossible to retain the very early age (36,000cal BP) attributed by some authors to the painted and engraved figures of Chauvet cave.