135,161 research outputs found
Female mating preferences in blind cave tetras Astyanax fasciatus (Characidae, Teleostei).
Full text linkThe Mexican tetra Astyanax fasciatus has evolved a variety of more or less color- and eyeless cave populations. Here we examined the evolution of the female preference for large male body size within different populations of this species, either surface- or cave-dwelling. Given the choice between visual cues from a large and a small male, females from the surface form as well as females from an eyed cave form showed a strong preference for large males. When only non-visual cues were presented in darkness, the surface females did not prefer either males. Among the six cave populations studied, females of the eyed cave form and females of one of the five eyeless cave populations showed a preference for large males. Apparently, not all cave populations of Astyanax have evolved non-visual mating preferences. We discuss the role of selection by benefits of non-visual mate choice for the evolution of non-visual mating preferences
The singer and the song: Nick Cave and the archetypal function of the cover version
No full textThroughout his career, from The Boys Next Door, through The Birthday Party, and with The Bad Seeds, Australian singer / songwriter Nick Cave has balanced his own set of creative voices alongside those of others through his choice of cover versions. Cave’s 1986 album with The Bad Seeds, ‘Kicking Against the Pricks’, is a collection of cover versions that spans American folk idioms (‘Black Betty’, ‘Hey Joe’, ‘The Singer’), Tin-Pan-Alley balladeering (‘Something’s Gotten Hold of my Heart’, ‘By the Time I Get to Phoenix’) and left-field alt-rock (‘All Tomorrow’s Parties’, ‘The Hammer Song’). Cave’s first single as a solo artist beyond the confines of The Birthday Party was a cover of ‘In The Ghetto’, made famous by Elvis Presley, and the cover version has been a noticeable presence in Cave’s work both in his live and recorded output ever since. This chapter seeks to understand the uses of Cave’s choices of cover versions, both in terms of the idiosyncrasies of his own interpretations, and the context within which Cave places himself as part of a wider musical community. Cave’s relationship to a pantheon of elder statesmen figures (Johnny Cash, Bob Dylan or Leonard Cohen for example) is understood as not only one of recognising influences, but also of placing Cave within a specific tradition or lineage. Equally, certain song forms such as the folk ballad or the blues lament are utilised to give shape and form to Cave’s wider concerns outside of the specific cover version. Cave’s reimagining of John Lee Hooker’s ‘Tupelo’, or Dylan’s ‘Wanted Man’ from The Firstborn is Dead (1985) provide clues to the uses of the cover to both articulate the individual interpreting the song, thus placing it within a personalised lexicon, and to connect the singer to traditions, or archetypes of performance that resonate in specific ways. Cave’s covers are never wholly reproductions, at times they are reworking's that might be seen to reconnect a song to a potential ‘lost truth’, at others they may be seen as parodies or homages that have more transparent aims. However at all times, the connections between Cave the singer and the latent archetypes inherent in the song provide provocative and loaded connections and values. This paper seeks to understand how Cave’s choices of cover versions, and his approaches to interpretation, shape not only the musical moment, but also our perceptions of Cave as an artist in a broader sens
New AMS (14)C dates from the early Upper Paleolithic sequence of Raqefet Cave, Mount Carmel, Israel
Get PDFRaqefet Cave (35°04'21"N, 32°39'17"W) is situated in the southeastern side of Mount Carmel in Israel (Figure 1) on the left bank of wadi Raqefet (230 m asl), ~50 m above the wadi bed. It is 50 m long with an area of ~500 m2 (Figure 2). Eric Higgs of Cambridge University and Tamar Noy of the Israel Museum conducted excavations at the site between 1970 and 1972 (Higgs et al. 1975). New excavations at the cave began in 2004 (Lengyel et al. 2005)
The ecology and conservation of cave roosting bats in the Yorkshire Dales
Full text linkThe caves of the Yorkshire Dales National Park are potentially an important assemblage of underground bat sites, but prior to this study nothing was known about the ecology of cave use. Between 2002 and 2005,53 cave entrances were logged for swarming activity using automated echolocation call loggers. A subset was chosen for continuous monitoring outside the hibernation period and another for winter logging. Logging was followed up by trapping at caves with significant autumn bat activity. All bats caught were ringed, identified to species and sexed. Biopsies (3 mm diameter) were taken from each wing for genetic analysis.
A large proportion of the caves surveyed were used by bats, but activity was concentrated in a small number of hotspots. Peak activity occurred during August and September, but significant activity was recorded in all months between March and October. All five swarming species were caught at most sites: Myotis brandtii, M. daubentonii, M. mystacinus, M. nattereri and Plecotus auritus. M. nattereri was the most abundant species late in September, but earlier other species made up a significant proportion of those caught. The sex ratio of swarming bats was heavily skewed towards males.
Swarming activity was positively correlated with the degree of cave chamber development, cave length and shelter at the entrance, and negatively correlated with the amount of water the cave carried. Entrance size, altitude and the degree of connectivity between cave and summer habitat were not correlated with activity. In a multiple regression model, chamber development and hydrology were the best predictors of activity. Entrance orientation and shelter contributed towards the model but were less important. The regression model could explain 55% of the variance in bat activity.
Genetic diversity of Myotis nattereri, based on an analysis of six microsatellite loci, was high in swarming populations suggesting high gene flow and large effective populations. Most of the genetic variation was explained by variation among individuals within populations, but some was due to differences between swarming areas and by differences between populations within swarming areas. Isolation by distance was found between sites in six swarming areas between Cumbria and Sussex, but not between sites in the Yorkshire Dales. The differentiation observed was more logically explained on the basis of local geography and probable catchment areas.
Preliminary experiments suggest that Time Domain Signal Coding has potential as a sound analysis system for real time bat call identification
The Late Natufian at Raqefet Cave: The 2006 Excavation Season
No full textA long season of excavation took place at Raqefet cave during the summer of 2006. In the
first chamber we exposed an area rich with Natufian human burials (Locus 1), a large bedrock
basin with a burial and two boulder mortars (Locus 2), an in situ Natufian layer (Locus 3),
and two areas with rich cemented sediments (tufa) covering the cave floor (Loci 4, 5). The
latter indicate that at the time of occupation the Natufian layers covered the entire floor of
the first chamber. During the ensuing millennia, these were washed away and/or removed
by later visitors to the cave. We found in the cave and the terrace almost 80 human-made
bedrock holes (most of which are commonly but somewhat erroneously termed mortars
and cupmarks). Several contained in situ Natufian remains, and at the top of one a human
skeleton was unearthed. The variety of the HBHs, in terms of shape and dimensions indicates
that they were used in many ways, some of which could not have been for food or mineral
processing. The paper provides results of on-going studies regarding the burials, the HBHs,
the flint assemblage, the faunal remains, the ground stone industry, the bone tools and the
beads. It also presents aspects of geoarchaeology and ground penetrating radar analyses.
Some of the detailed plans and sections were prepared by the use of photogrammetry
The impact of declining groundwater levels on Stygofauna communities in the Leeuwin naturaliste ridge cave systems, Western Australia
Full text linkGroundwater Dependent Ecosystems (GDE 19s) are intrinsically connected to rainfall and groundwater for survival. Many ecosystems are becoming increasingly threatened due to the accelerating pressures of climate change and disturbances to connecting ecosystems. This thesis examined the structural changes of the Threatened Ecological Communities (TEC 19s) living within the GDE of Leeuwin Naturaliste Ridge (LNR) and Yanchep, Western Australia, as well as water quality of each of these cave systems. Multidimensional scaling, Simper analysis and BIOENV techniques were used to characterize and compare water quality, quantity and community structure. It was found that each cave contained a distinct faunal community contribution and that three caves of LNR were distinct in their ionic compositions. Factors that may have contributed to the biological and physical differentiation of these caves include the extensive evolutionary and hydrogeological development of each cave. Threats to cave systems were also identified, including climate change induced rainfall decline and anthropogenic stressors. Finally, management strategies for future conservation were suggested. Overall, reduced groundwater levels induced by rainfall decline seemed to have an important effect on cave TEC
Bacterial metabolism of methylated amines and identification of novel methylotrophs in Movile Cave
Full text linkMovile Cave, Romania, is an unusual underground ecosystem that has been sealed off from the outside world for several million years and is sustained by non-phototrophic carbon fixation. Methane and sulfur-oxidising bacteria are the main primary producers, supporting a complex food web that includes bacteria, fungi and cave-adapted invertebrates. A range of methylotrophic bacteria in Movile Cave grow on one-carbon compounds including methylated amines, which are produced via decomposition of organic-rich microbial mats. The role of methylated amines as a carbon and nitrogen source for bacteria in Movile Cave was investigated using a combination of cultivation studies and DNA stable isotope probing (DNA-SIP) using 13C-monomethylamine (MMA). Two newly developed primer sets targeting the gene for gamma-glutamylmethylamide synthetase (gmaS), the first enzyme of the recently-discovered indirect MMA-oxidation pathway, were applied in functional gene probing. SIP experiments revealed that the obligate methylotroph Methylotenera mobilis is one of the dominant MMA utilisers in the cave. DNA-SIP experiments also showed that a new facultative methylotroph isolated in this study, Catellibacterium sp. LW-1 is probably one of the most active MMA utilisers in Movile Cave. Methylated amines were also used as a nitrogen source by a wide range of non-methylotrophic bacteria in Movile Cave. PCR-based screening of bacterial isolates suggested that the indirect MMA-oxidation pathway involving GMA and N-methylglutamate is widespread among both methylotrophic and non-methylotrophic MMA utilisers from the cave
Measure the Evacuees Preference on ArchitecturalCues by CAVE
Full text linkAn evacueesi preference prediction function on architectural cues are described here as a crucial part of the evacuation model to simulate how the evacuees search the route to exit according to the architectural information in the public underground space. The model is developed to evaluate the egress design in the initial space design stage and to provide the existing compositive evacuation models a support on the usage of architectural information. First the over simplification on the architectural information in the existing evacuation models is discussed. Then a list of so-called architectural cues and the related evacuation model are introduced, in which the evacuees always egress to the seen or remembered architectural cue with the highest preference in every step. The emphasis of the paper is put on the analysis of the preference function including the CAVE-based conjoint analysis research method, the experiment design and implementation of the virtual drill, and the estimation of the parameters from the collected choices. The preference function for five architectural cue pairs, Doorway-Doorway, Stair-Stair, Exit- Exit, Doorway-Stair, Exit-Stair is built from the choice data of nearly one hundred Chinese subjects.
Characterization of Macro-and Micro-Geomorphology of Cave Channel from High-Resolution 3D Laser Scanning Survey: Case Study of Gomantong Cave in Sabah, Malaysia
Full text linkThree-dimensional documentation of hypogene cave morphology is one of the major applications of laser scanning survey. This chapter presents applications of terrestrial laser scanning (TLS) survey for analyzing endogenic cave passage geomorphologic structure and morphometry using 3D meshing, high-resolution 3D texture modeling for geovisualization, and its potential for cave art documentation. To achieve this, multi-scale resolution 3D models were generated; one using the mesh model for macro-morphological analysis and the other with the full-resolution scan to produce high quality 3D texture model for identification of micro-morphological features. The mesh model of the cave makes it possible to analyze the general shape, distinguish phreatic tube from post-speleogenetic modified conduits and carry out morphometric measurements including the cave volume and channel surface area. The 3D texture model provides true to live visualization of the cave with exceptionally high level of accuracy and details that would be impossible to obtain with direct observation by visiting the site or from the mesh model. The model allows discerning different speleogenetic phases, karstification processes and micro-morphologies such as wall and ceiling seepage, hanging rocks, fractures, scallops, ceiling flush dome, pockets, bell-hole and avens. Also, the texture model permits identifying cave arts and engravings along the passage
Non-anthropogenic sources of carbon dioxide in the Glowworm Cave, Waitomo
No full textThe Waitomo Caves attract approximately 500 000 tourists each year. A requirement of tourist cave management is that the partial pressure of carbon dioxide (PCO₂) is kept below levels that are: hazardous to the health of visitors, hazardous to the glowworms and other natural inhabitants, or potentially corrosive to speleothems. For the Glowworm Cave at Waitomo, the maximum permissible PCO₂ level is 2400 ppm. When exceeded, the tourist operators are required to close the cave. Ten years of monitoring data at the Glowworm Cave was analysed. Most of the variation in PCO₂ could be attributed to CO₂ respired by tourists, and the mixing of cave air with lower PCO₂ outside air. Occasionally, there were periods with high PCO₂ levels while the cave was closed to tourists. The main objective of this study was to investigate the potential role of the Waitomo Stream in contributing CO₂ to the Glowworm Cave atmosphere.
Analysis of ten years of Glowworm Cave monitoring data showed that the 2400 ppm PCO₂ limit was, on average, exceeded five times each year, with a total of 48 events between 1998 and 2007. Of the PCO₂ limit exceedences, approximately 31% of events were largely driven by high tourist numbers; 27% of PCO₂ limit exceedences were mainly driven by increased discharge, rainfall, and/or a low temperature gradient between the cave and outside air, whilst 29% of the PCO₂ limit exceedences were due to a combination of tourists and increased discharge, rainfall, and/or a low temperature gradient. The remaining 13% of exceedences were unexplained by tourists or the factors investigated. It may be that the unexplained exceedences were due to the night time closure of the cave door, restricting air exchange.
The PCO₂ of the Waitomo Stream was measured by equilibrating air with the streamwater within a closed loop. The air was passed continuously through an infrared gas analyser (IRGA). The streamwater PCO₂ typically ranged between 600 - 1200 ppm. Fluctuations in the PCO₂ of the Waitomo Stream coincided with PCO₂ fluctuations in the Glowworm Cave air, and under most conditions, the stream probably acted as a sink for cave air CO₂. However, following rainfall events, the stream PCO₂ increased, exceeding cave air PCO₂, thus acting as a source of CO₂ to the cave air. High stream PCO₂ often occurred at times when air flow through the cave was restricted, e.g. when the temperature gradient between the cave air and outside air was low, or stream levels were high, thus limiting air movement. The combination of high stream PCO₂ and a low temperature gradient increased the likelihood of high cave air PCO₂.
Dripwater was measured to determine whether an increase in dripwater PCO₂ occurred in response to rainfall events. When rainfall events resulted in increased discharge, the dripwater PCO₂ sometimes increased (occasionally exceeding 5000 ppm), however the pattern was not consistent.
The chemistry of the Waitomo and Okohua (Ruakuri) Streams was monitored with daily samples collected and analysed for major ions: HCO₃ -, Ca²⁺, Na⁺ and Mg²⁺, and δ¹³C stable isotope. The HCO₃ -, Ca²⁺, Na⁺ and Mg²⁺ concentrations in the streamwater decreased with increased discharge, presumably due to dilution. Increased discharge following rainfall events correlated with increasing PCO₂ in the Waitomo Stream, suggesting that soil atmosphere CO₂ dissolved in soil waters, and carried to the stream by saturated flow, was responsible for the streamwater PCO₂ increase. Ca in the stream showed both an increase and a decrease with respect to rainfall. Increased Ca in the stream occurred at times when the discharged waters were coming from the phreatic zone, and thus sufficient time had lapsed for CO₂ in the discharge waters to react with the limestone (carbonate dissolution reaction). Decreased Ca occurred when the infiltration and percolation of rainwater was rapid, and thus the streamwater was characterised by a higher PCO₂ and a lower Ca concentration, as insufficient time had lapsed for the discharge waters to equilibrate with the limestone.
Increased negativity in the δ¹³C of the Waitomo and Ruakuri Streams coincided with increased discharge. During summer low flow, the δ¹³C of Waitomo Stream waters was -11.3‰, whereas during high stream discharge events, the δ¹³C dropped to -12 - -14‰. The δ¹³C of limestone is 0‰, the atmosphere is -7‰, and the soil atmosphere is reported to be about -24‰, thus the decrease in δ¹³C during high flow events supports the contention that soil atmosphere CO₂ is a likely source of the increased CO₂ in flood waters
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