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Sample records for cave bears evidenced

  1. Predormancy omnivory in European cave bears evidenced by a dental microwear analysis of Ursus spelaeus from Goyet, Belgium

    PubMed Central

    Peigné, Stéphane; Goillot, Cyrielle; Germonpré, Mietje; Blondel, Cécile; Bignon, Olivier; Merceron, Gildas

    2009-01-01

    Previous morphological and isotopic studies indicate that Late Pleistocene cave bear (Ursus spelaeus) diet ranged from mostly vegetarian to omnivory or even carnivory. However, such analyses do not provide information on seasonal diets, and only provide an average record of diet. A dental microwear analysis of 43 young and adult individuals demonstrate that, during the predormancy period, cave bears from Goyet (Late Pleistocene, Belgium) were not strictly herbivorous, but had a mixed diet composed of hard items (e.g., possibly bone), invertebrates (e.g., insects), meat (ungulates, small vertebrates), and/or plant matter (hard mast, seeds, herbaceous vegetations, and fruits). Therefore, our results indicate that cave bears at Goyet were generalist omnivores during the predormancy period, which is consistent with current data on the dietary ecology of extant bears during this season. These data also raise questions about the ecological role and causes of the extinction of cave bears. PMID:19706401

  2. Predormancy omnivory in European cave bears evidenced by a dental microwear analysis of Ursus spelaeus from Goyet, Belgium.

    PubMed

    Peigné, Stéphane; Goillot, Cyrielle; Germonpré, Mietje; Blondel, Cécile; Bignon, Olivier; Merceron, Gildas

    2009-09-08

    Previous morphological and isotopic studies indicate that Late Pleistocene cave bear (Ursus spelaeus) diet ranged from mostly vegetarian to omnivory or even carnivory. However, such analyses do not provide information on seasonal diets, and only provide an average record of diet. A dental microwear analysis of 43 young and adult individuals demonstrate that, during the predormancy period, cave bears from Goyet (Late Pleistocene, Belgium) were not strictly herbivorous, but had a mixed diet composed of hard items (e.g., possibly bone), invertebrates (e.g., insects), meat (ungulates, small vertebrates), and/or plant matter (hard mast, seeds, herbaceous vegetations, and fruits). Therefore, our results indicate that cave bears at Goyet were generalist omnivores during the predormancy period, which is consistent with current data on the dietary ecology of extant bears during this season. These data also raise questions about the ecological role and causes of the extinction of cave bears.

  3. Genomic sequencing of Pleistocene cave bears.

    PubMed

    Noonan, James P; Hofreiter, Michael; Smith, Doug; Priest, James R; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J Chris; Pääbo, Svante; Rubin, Edward M

    2005-07-22

    Despite the greater information content of genomic DNA, ancient DNA studies have largely been limited to the amplification of mitochondrial sequences. Here we describe metagenomic libraries constructed with unamplified DNA extracted from skeletal remains of two 40,000-year-old extinct cave bears. Analysis of approximately 1 megabase of sequence from each library showed that despite significant microbial contamination, 5.8 and 1.1% of clones contained cave bear inserts, yielding 26,861 base pairs of cave bear genome sequence. Comparison of cave bear and modern bear sequences revealed the evolutionary relationship of these lineages. The metagenomic approach used here establishes the feasibility of ancient DNA genome sequencing programs.

  4. Genomic sequencing of Pleistocene cave bears

    SciTech Connect

    Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

    2005-04-01

    Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

  5. Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.

    PubMed

    Fortes, Gloria G; Grandal-d'Anglade, Aurora; Kolbe, Ben; Fernandes, Daniel; Meleg, Ioana N; García-Vázquez, Ana; Pinto-Llona, Ana C; Constantin, Silviu; de Torres, Trino J; Ortiz, Jose E; Frischauf, Christine; Rabeder, Gernot; Hofreiter, Michael; Barlow, Axel

    2016-10-01

    Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago.

  6. Spotted hyena and steppe lion predation behaviours on cave bears of Europe - ?Late Quaternary cave bear extinction as result of predator stress

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2010-05-01

    Cave bears hibernated in caves all over Eurasia (e.g. Rabeder et al., 2000) including alpine regions using mainly larger caves for this purpose. Late Quaternary spotted hyenas Crocuta crocuta spelaea instead occupied mainly areas close to the cave entrances as their dens (Diedrich and Žák 2006, Diedrich 2010). The largest predator, the steppe lion Panthera leo spelaea was only a sporadic cave dweller (Diedrich 2007b, 2009b). His presence and its remains from caves all over Europe can be recently explained best as result of imported carcasses after killing by their largest antagonists, the Late Quaternary spotted hyenas. In some cases the kill might have happened in the hyena den cave itself during the theft of prey remains by lions (Diedrich 2009a). Another reason of their remains in caves of Europe is the hunting onto the herbivorous cave bears, especially during hibernation times, when megafauna prey was less available in the open environments (Diedrich 2009c). These lion remains from caves of Europe, nearly all of which were from adult animals, provide evidence of active predation by lions onto cave bears even in medium high alpine regions (Diedrich 2009b, in review). Lion skeletons in European cave bear dens were therefore often found amongst originally articulated cave bear skeletons or scattered cave bear remains and even close to their hibernation nests (Diedrich et al. 2009c, in review). Not only lions fed on cave bears documented mainly by the large quantities of chewed, punctured and crushed cave bear long-bones; even damaged skulls reveal that hyenas scavenged primarily on cave bear carcasses which were mainly responsible for the destruction of their carcasses and bones (Diedrich 2005, 2009d). Predation and scavenging on cave bears by the two largest Late Quaternary predators C. c. spelaea and P. l. spelaea explains well the large quantity of fragmented cave bear bones over all European caves in low to medium high mountainous elevations, whereas in

  7. Late Quaternary cave bears and brown bears in Europe: implications for distribution, chronology, and extinction based on a multidisciplinary approach

    NASA Astrophysics Data System (ADS)

    Pacher, Martina

    2010-05-01

    Cave bear remains are one of the most numerous fossils found in European caves. Despite their frequency of occurrence, many aspects of cave bear palaeontology still remain poorly understood. New methodological approaches and ongoing studies led to controversial results and discussion about its taxonomy, palaeoecology, and final extinction. Are we dealing with one single or several species of cave bears? Was cave bear exclusively vegetarian or after all more omnivorous? Did he go extinct before or after the Late Glacial Maximum? Was cave bear restricted to Europe or did he also occur in Asia? Late Pleistocene brown bears, on the other hand, are often rare and little is known about the possible co-occurrence of cave and brown bears during the Late Pleistocene. Based on direct radiocarbon dates the distribution pattern of both, cave and brown bears is reconstructed during the Late Pleistocene in Europe. In addition, the reasons for the achieved pattern will be tested leading to the main question - why did cave bear become extinct while brown bears survived until today? To answer this question palaeobiological data of Late Pleistocene cave and brown bears will be tested against results from isotope analyses, while aDNA data may contribute to the question of distinct local population or even species of bears. The current state of evidence will be presented and on the basis of resulting pattern implications for further multi-disciplinary studies will be discussed.

  8. ‘Neanderthal bone flutes’: simply products of Ice Age spotted hyena scavenging activities on cave bear cubs in European cave bear dens

    PubMed Central

    Diedrich, Cajus G.

    2015-01-01

    Punctured extinct cave bear femora were misidentified in southeastern Europe (Hungary/Slovenia) as ‘Palaeolithic bone flutes’ and the ‘oldest Neanderthal instruments’. These are not instruments, nor human made, but products of the most important cave bear scavengers of Europe, hyenas. Late Middle to Late Pleistocene (Mousterian to Gravettian) Ice Age spotted hyenas of Europe occupied mainly cave entrances as dens (communal/cub raising den types), but went deeper for scavenging into cave bear dens, or used in a few cases branches/diagonal shafts (i.e. prey storage den type). In most of those dens, about 20% of adult to 80% of bear cub remains have large carnivore damage. Hyenas left bones in repeating similar tooth mark and crush damage stages, demonstrating a butchering/bone cracking strategy. The femora of subadult cave bears are intermediate in damage patterns, compared to the adult ones, which were fully crushed to pieces. Hyenas produced round–oval puncture marks in cub femora only by the bone-crushing premolar teeth of both upper and lower jaw. The punctures/tooth impact marks are often present on both sides of the shaft of cave bear cub femora and are simply a result of non-breakage of the slightly calcified shaft compacta. All stages of femur puncturing to crushing are demonstrated herein, especially on a large cave bear population from a German cave bear den. PMID:26064624

  9. Deciphering the complete mitochondrial genome and phylogeny of the extinct cave bear in the Paleolithic painted cave of Chauvet.

    PubMed

    Bon, Céline; Caudy, Nicolas; de Dieuleveult, Maud; Fosse, Philippe; Philippe, Michel; Maksud, Frédéric; Beraud-Colomb, Eliane; Bouzaid, Eric; Kefi, Rym; Laugier, Christelle; Rousseau, Bernard; Casane, Didier; van der Plicht, Johannes; Elalouf, Jean-Marc

    2008-11-11

    Retrieving a large amount of genetic information from extinct species was demonstrated feasible, but complete mitochondrial genome sequences have only been deciphered for the moa, a bird that became extinct a few hundred years ago, and for Pleistocene species, such as the woolly mammoth and the mastodon, both of which could be studied from animals embedded in permafrost. To enlarge the diversity of mitochondrial genomes available for Pleistocene species, we turned to the cave bear (Ursus spelaeus), whose only remains consist of skeletal elements. We collected bone samples from the Paleolithic painted cave of Chauvet-Pont d'Arc (France), which displays the earliest known human drawings, and contains thousands of bear remains. We selected a cave bear sternebra, radiocarbon dated to 32,000 years before present, from which we generated overlapping DNA fragments assembling into a 16,810-base pair mitochondrial genome. Together with the first mitochondrial genome for the brown bear western lineage, this study provides a statistically secured molecular phylogeny assessing the cave bear as a sister taxon to the brown bear and polar bear clade, with a divergence inferred to 1.6 million years ago. With the first mitochondrial genome for a Pleistocene carnivore to be delivered, our study establishes the Chauvet-Pont d'Arc Cave as a new reservoir for Paleogenetic studies. These molecular data enable establishing the chronology of bear speciation, and provide a helpful resource to rescue for genetic analysis archeological samples initially diagnosed as devoid of amplifiable DNA.

  10. Withering away--25,000 years of genetic decline preceded cave bear extinction.

    PubMed

    Stiller, Mathias; Baryshnikov, Gennady; Bocherens, Hervé; Grandal d'Anglade, Aurora; Hilpert, Brigitte; Münzel, Susanne C; Pinhasi, Ron; Rabeder, Gernot; Rosendahl, Wilfried; Trinkaus, Erik; Hofreiter, Michael; Knapp, Michael

    2010-05-01

    The causes of the late Pleistocene megafaunal extinctions are still enigmatic. Although the fossil record can provide approximations for when a species went extinct, the timing of its disappearance alone cannot resolve the causes and mode of the decline preceding its extinction. However, ancient DNA analyses can reveal population size changes over time and narrow down potential causes of extinction. Here, we present an ancient DNA study comparing late Pleistocene population dynamics of two closely related species, cave and brown bears. We found that the decline of cave bears started approximately 25,000 years before their extinction, whereas brown bear population size remained constant. We conclude that neither the effects of climate change nor human hunting alone can be responsible for the decline of the cave bear and suggest that a complex of factors including human competition for cave sites lead to the cave bear's extinction.

  11. Hominid exploitation of the environment and cave bear populations. The case of Ursus spelaeus Rosenmüller-Heinroth in Amutxate cave (Aralar, Navarra-Spain).

    PubMed

    Torres, Trinidad; Ortiz, José E; Cobo, Rafael; de Hoz, Pedro; García-Redondo, Ana; Grün, Rainer

    2007-01-01

    Cave bears (Ursus deningeri and U. spelaeus) and hominids (Homo heidelbergensis, H. neanderthalensis, and H. sapiens) were potential competitors for environmental resources (subterranean and open air). Here, we examined the age at death of cave bear (Ursus spelaeus Rosenmüller-Heinroth) specimens from Amutxate cave in order to shed light on the effect of resource sharing between cave bears and hominids. After studying dental wear of the deciduous and permanent dentitions, the ontogenetic development of mandibles, and incremental layers of cement (annuli), we defined five age groups differentiated by marked development and size gaps. Our findings indicate that after hibernating, bears abandoned the den, thereby leaving the subterranean environment (caves) free for temporary hominid occupation-this would explain the subtle traces of hominid presence in many dens. However, a simple calculation based on age at death of subadult and adult cave bear specimens in Amutxate cave, extrapolated to the whole cave area, showed that the area surrounding this cave hosted bears for at least 9,000 years. This length of habitation, quite similar to the time-span derived from amino acid racemization and electron spin resonance, indicates that bear populations in the Amutxate cave constituted a serious constraint for hominid exploitation of the environment.

  12. Isotopic variability of cave bears (δ15N, δ13C) across Europe during MIS 3

    NASA Astrophysics Data System (ADS)

    Krajcarz, Magdalena; Pacher, Martina; Krajcarz, Maciej T.; Laughlan, Lana; Rabeder, Gernot; Sabol, Martin; Wojtal, Piotr; Bocherens, Hervé

    2016-01-01

    Collagen, the organic fraction of bone, records the isotopic parameters of consumed food for carbon (δ13C) and nitrogen (δ15N). This relationship of isotopic signature between diet and tissue is an important tool for the study of dietary preferences of modern and fossil animal species. Since the first information on the isotopic signature of cave bear was reported, numerous data from Europe have become available. The goal of this work is to track the geographical variation of cave bear collagen isotopic values in Europe during Marine Isotopic Stage 3 (about 60,000-25,000 yr BP). In this study the results of new δ13C and δ15N isotopic analyses of cave bear collagen from four Central-Eastern European sites are presented, as well as a review of all published isotopic data for cave bears of the same period. The main conclusion is a lack of geographical East-West pattern in the variations of δ13C and δ15N values of cave bear collagen. Moreover, no relationship was found between cave bear taxonomy and isotopic composition. The cave bears from Central-Eastern Europe exhibit δ13C and δ15N values near the average of the range of Central, Western and Southern European cave bears. Despite the fact that most cave bear sites follow an altitudinal gradient, separate groups of sites exhibit shift in absolute values of δ13C, what disturbs an altitude-related isotopic pattern. The most distinct groups are: high Alpine sites situated over 1500 m a.s.l. - in terms of δ13C; and two Romanian sites Peştera cu Oase and Urşilor - in case of δ15N. Although the cave bear isotopic signature is driven by altitude, the altitudinal adjustment of isotopic data is not enough to explain the isotopic dissimilarity of these cave bears. The unusually high δ15N signature of mentioned Romanian sites is an isolated case in Europe. Cave bears from relatively closely situated Central-Eastern European sites and other Romanian sites are more similar to Western European than to Romanian

  13. Retreat and extinction of the Late Pleistocene cave bear ( Ursus spelaeus sensu lato)

    NASA Astrophysics Data System (ADS)

    Baca, Mateusz; Popović, Danijela; Stefaniak, Krzysztof; Marciszak, Adrian; Urbanowski, Mikołaj; Nadachowski, Adam; Mackiewicz, Paweł

    2016-12-01

    The cave bear ( Ursus spelaeus sensu lato) is a typical representative of Pleistocene megafauna which became extinct at the end of the Last Glacial. Detailed knowledge of cave bear extinction could explain this spectacular ecological transformation. The paper provides a report on the youngest remains of the cave bear dated to 20,930 ± 140 14C years before present (BP). Ancient DNA analyses proved its affiliation to the Ursus ingressus haplotype. Using this record and 205 other dates, we determined, following eight approaches, the extinction time of this mammal at 26,100-24,300 cal. years BP. The time is only slightly earlier, i.e. 27,000-26,100 cal. years BP, when young dates without associated collagen data are excluded. The demise of cave bear falls within the coldest phase of the last glacial period, Greenland Stadial 3. This finding and the significant decrease in the cave bear records with cooling indicate that the drastic climatic changes were responsible for its extinction. Climate deterioration lowered vegetation productivity, on which the cave bear strongly depended as a strict herbivore. The distribution of the last cave bear records in Europe suggests that this animal was vanishing by fragmentation into subpopulations occupying small habitats. One of them was the Kraków-Częstochowa Upland in Poland, where we discovered the latest record of the cave bear and also two other, younger than 25,000 14C years BP. The relatively long survival of this bear in karst regions may result from suitable microclimate and continuous access to water provided by deep aquifers, indicating a refugial role of such regions in the Pleistocene for many species.

  14. Retreat and extinction of the Late Pleistocene cave bear (Ursus spelaeus sensu lato).

    PubMed

    Baca, Mateusz; Popović, Danijela; Stefaniak, Krzysztof; Marciszak, Adrian; Urbanowski, Mikołaj; Nadachowski, Adam; Mackiewicz, Paweł

    2016-12-01

    The cave bear (Ursus spelaeus sensu lato) is a typical representative of Pleistocene megafauna which became extinct at the end of the Last Glacial. Detailed knowledge of cave bear extinction could explain this spectacular ecological transformation. The paper provides a report on the youngest remains of the cave bear dated to 20,930 ± 140 (14)C years before present (BP). Ancient DNA analyses proved its affiliation to the Ursus ingressus haplotype. Using this record and 205 other dates, we determined, following eight approaches, the extinction time of this mammal at 26,100-24,300 cal. years BP. The time is only slightly earlier, i.e. 27,000-26,100 cal. years BP, when young dates without associated collagen data are excluded. The demise of cave bear falls within the coldest phase of the last glacial period, Greenland Stadial 3. This finding and the significant decrease in the cave bear records with cooling indicate that the drastic climatic changes were responsible for its extinction. Climate deterioration lowered vegetation productivity, on which the cave bear strongly depended as a strict herbivore. The distribution of the last cave bear records in Europe suggests that this animal was vanishing by fragmentation into subpopulations occupying small habitats. One of them was the Kraków-Częstochowa Upland in Poland, where we discovered the latest record of the cave bear and also two other, younger than 25,000 (14)C years BP. The relatively long survival of this bear in karst regions may result from suitable microclimate and continuous access to water provided by deep aquifers, indicating a refugial role of such regions in the Pleistocene for many species.

  15. Radiocarbon dates on cave bear (Ursus spelaeus) and brown bear (Ursus arctos) from Late Pleistocene of Poland

    NASA Astrophysics Data System (ADS)

    Nadachowski, Adam; Lipecki, Grzegorz; Stefaniak, Krzysztof; Wojtal, Piotr

    2010-05-01

    Although cave bear (Ursus spelaeus) is far more abundant in last glacial in Europe than brown bear (Ursus arctos), the co-occurrence of both species during Oxygen Isotope Stage 3 (OIS 3) is not questioned. The cave bear (Ursus spelaeus) has been an important part of the European large mammal fauna of last glaciation. Most of the remains come from karst areas where larger caves were used as hibernation sites. In Poland caves occur in the Sudetes Mts, Kraków-Częstochowa Upland, Świętokrzyskie Mts and in the Carpathians (especially in Tatra and Pieniny Mts). The AMS 14C dates were obtained for 14 sites (23 dates) distributed in all karst areas of Poland. All samples dated in Poznań Radiocarbon Laboratory (Poz) were subject of pre-treatment procedures (ultrafiltration and removal of consolidants). Dates are given as an uncalibrated radiocarbon dates (BP) and as calendar dates (cal. BP). The Eastern Sudetes sites are represented by two cave bear remains from Niedźwiedzia Cave, Kletno. Most of samples come from several localities located in different parts of Kraków-Częstochowa Upland (Nietoperzowa, Mamutowa, Ciemna, Wylotne and Zawalona caves - all near Kraków; Komarowa, Deszczowa, Stajnia and Niedźwiedzia near Olsztyn caves - all from the middle part of the Upland). Raj Cave is located in Świętokrzyskie Mts. The Carpathians samples come from two caves in Tatra Mts: Magurska and Poszukiwaczy Skarbów. Results obtained suggest that in the early part of OIS 3, ca. 50-33 ka (ca. 54-37,5 cal. ka), when the climate was relatively stable and warm, cave bears occurred probably more or less continuously from Sudetes Mts to Kraków-Częstochowa Upland and in the Carpathians. The available 18 dates range from >52,000 BP (Poz-24205) to 33,000±400 BP (Poz-23655) (cal. 38,571±1,449 BP). Around 33 ka BP (cal. 38,5 ka BP) cave bears probably disappeared, or at least reduced their number, in the area north from Sudetes and the Carpathians for next ca. 4-5 millennia

  16. Hominin-bearing caves and landscape dynamics in the Cradle of Humankind, South Africa

    NASA Astrophysics Data System (ADS)

    Dirks, Paul H. G. M.; Berger, Lee R.

    2013-02-01

    sediment traps on the landscape. Caves in the CoH are distributed along lithological boundaries and NNE and ESE fractures. Fossil-bearing caves have a distinct distribution pattern, with different directional controls, a high degree of clustering, a characteristic spacing of 1700 m or 3400 m, and a characteristic bi-model fractal distribution best explained by a combination of geological and biological controls. It is suggested that clustering of fossil-bearing caves reflects a Lévy flight patterns typical for foraging behavior in animals. The controlling element in this behavior could have been availability of water in or near groups of caves, resulting in preferential occupation of these caves with accumulation of diverse faunal fossil assemblages. The tectonic drivers shaping the dynamic landscape of the CoH did not involve large, seismically active fault lines, but complex interactions between multiple smaller fractures and joints activated in a far field stress controlled by uplift. The landscape of the CoH, with its caves and water sources and dissected landscape provided a setting favored by many animals including hominins. A modern day analog for what the CoH would have looked like 2 My ago is found 50 km east of Johannesburg, near the SE margin of the Johannesburg Dome.

  17. Stratigraphy, U-Th chronology, and paleoenvironments at Gladysvale Cave: insights into the climatic control of South African hominin-bearing cave deposits.

    PubMed

    Pickering, Robyn; Hancox, Phillip J; Lee-Thorp, Julia A; Grün, Rainer; Mortimer, Graham E; McCulloch, Malcolm; Berger, Lee R

    2007-11-01

    Gladysvale Cave is one of the few Plio-Pleistocene hominin-bearing cave sites in South Africa that contains a well-stratified cave fill with clastic sediments interspersed with flowstones. The clastic sediments can be divided into units based on the presence of intercalated flowstones, forming flowstone bounded units (FBU). Ten MC-ICP-MS uranium-series dates on several flowstone horizons in the Gladysvale Internal Deposit fan indicate deposition from the late mid-Pleistocene ( approximately 570 ka) to Holocene ( approximately 7 ka) during limited periods of higher effective moisture. Clastic sedimentation occurred during the interceding, presumably more arid, periods. This sequence is not consistent with earlier models for South African caves that simply assumed interglacial sedimentation and glacial erosion. (13)C/(12)C data suggest that flowstone tended to form during periods with higher proportions of C(3) plants in the local vegetation, while clastic sediments reflect higher proportions of C(4) grasses, although this is not always the case. We argue that flowstones are precipitated during periods of higher effective precipitation and restricted cave entrances, while clastic sediments accumulated during periods with more open vegetation. The sedimentary fill of the fossiliferous deposits are, therefore, highly episodic in nature, with large periods of time unlikely to be represented. This has serious implications for the other hominin-bearing caves close by, as these deposits are likely to be similarly episodic. This is especially pertinent when addressing extinction events and reconstructions of paleoenvironments, as large periods of time may be unrecorded. The Gladysvale Cave fill sediments may serve as a climatically forced chronostratigraphic model for these less well-stratified and well-dated Plio-Pleistocene sites.

  18. Complete mitochondrial genome sequence of a Middle Pleistocene cave bear reconstructed from ultrashort DNA fragments.

    PubMed

    Dabney, Jesse; Knapp, Michael; Glocke, Isabelle; Gansauge, Marie-Theres; Weihmann, Antje; Nickel, Birgit; Valdiosera, Cristina; García, Nuria; Pääbo, Svante; Arsuaga, Juan-Luis; Meyer, Matthias

    2013-09-24

    Although an inverse relationship is expected in ancient DNA samples between the number of surviving DNA fragments and their length, ancient DNA sequencing libraries are strikingly deficient in molecules shorter than 40 bp. We find that a loss of short molecules can occur during DNA extraction and present an improved silica-based extraction protocol that enables their efficient retrieval. In combination with single-stranded DNA library preparation, this method enabled us to reconstruct the mitochondrial genome sequence from a Middle Pleistocene cave bear (Ursus deningeri) bone excavated at Sima de los Huesos in the Sierra de Atapuerca, Spain. Phylogenetic reconstructions indicate that the U. deningeri sequence forms an early diverging sister lineage to all Western European Late Pleistocene cave bears. Our results prove that authentic ancient DNA can be preserved for hundreds of thousand years outside of permafrost. Moreover, the techniques presented enable the retrieval of phylogenetically informative sequences from samples in which virtually all DNA is diminished to fragments shorter than 50 bp.

  19. Complete mitochondrial genome sequence of a Middle Pleistocene cave bear reconstructed from ultrashort DNA fragments

    PubMed Central

    Dabney, Jesse; Knapp, Michael; Glocke, Isabelle; Gansauge, Marie-Theres; Weihmann, Antje; Nickel, Birgit; Valdiosera, Cristina; García, Nuria; Pääbo, Svante; Arsuaga, Juan-Luis; Meyer, Matthias

    2013-01-01

    Although an inverse relationship is expected in ancient DNA samples between the number of surviving DNA fragments and their length, ancient DNA sequencing libraries are strikingly deficient in molecules shorter than 40 bp. We find that a loss of short molecules can occur during DNA extraction and present an improved silica-based extraction protocol that enables their efficient retrieval. In combination with single-stranded DNA library preparation, this method enabled us to reconstruct the mitochondrial genome sequence from a Middle Pleistocene cave bear (Ursus deningeri) bone excavated at Sima de los Huesos in the Sierra de Atapuerca, Spain. Phylogenetic reconstructions indicate that the U. deningeri sequence forms an early diverging sister lineage to all Western European Late Pleistocene cave bears. Our results prove that authentic ancient DNA can be preserved for hundreds of thousand years outside of permafrost. Moreover, the techniques presented enable the retrieval of phylogenetically informative sequences from samples in which virtually all DNA is diminished to fragments shorter than 50 bp. PMID:24019490

  20. Contemporary flowstone development links early hominin bearing cave deposits in South Africa

    NASA Astrophysics Data System (ADS)

    Pickering, Robyn; Kramers, Jan D.; Hancox, Philip John; de Ruiter, Darryl J.; Woodhead, Jon D.

    2011-06-01

    The Cradle of Humankind cave sites in South Africa preserve fossil evidence of four early hominin taxa: Australopithecus africanus, Australopithecus sediba, Paranthropus robustus and early Homo. In order to integrate this record into a pan-African scenario of human evolutionary history it is critical to have reliable dates and temporal ranges for the southern African hominins. In the past a lack of precise and accurate chronological data has prevented the evaluation of the temporal relationships between the various sites. Here we report new uranium-lead (U-Pb) radiometric ages obtained from sheets of calcium carbonate flowstone inter-bedded between clastic cave sediments at the site of Swartkrans, providing bracketing ages for the fossiliferous deposits. The fossil bearing units of Swartkrans, specifically the Hanging Remnant and Lower Bank of Member 1, are underlain by flowstone layers dated to 2.25 ± 0.05 Ma and 2.25 ± 0.08 Ma and capped by layers of 1.8 ± 0.01 Ma and 1.7 ± 0.07 Ma. The age bracket of the Member 1 deposits is therefore between 2.31 and 1.64 Ma. However, by combining the U-Pb with biostratigraphic data we suggest that this can be narrowed down to between 1.9 and 1.8 Ma. These data can be compared with other recently dated sites and a radiometrically dated U-Pb age sequence formed: Sterkfontein Member 4, Swartkrans Member 1, Malapa, and Cooper's D. From this new U-Pb dataset, a pattern of contemporary flowstone development emerges, with different caves recording the same flowstone-forming event. Specifically overlapping flowstone formation takes place at Swartkrans and Sterkfontein at ~ 2.29 Ma and ~ 1.77 Ma, and at Sterkfontein and Malapa at ˜ 2.02 Ma. This suggests a regional control over the nature and timing of speleothem development in cave deposits and these flowstone layers could assist in future correlation, both internal to specific deposits and regionally between sites.

  1. Geophysical observations and structural models of shallow caves in gypsum/anhydrite-bearing rocks in Germany

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Romanov, Douchko

    2016-04-01

    In northern Germany, the evaporitic sequence of Zechstein rocks outcrops at several locations, offering insight into both surface and sub-surface morphology of the soluble rocks. We discuss two field sites, an active shallow gypsum cave in the southern Harz Mountains, and an active shallow anhydrite/gypsum cave close to Bad Segeberg, which both have been explored from the surface by geophysical surveys. The overburden of the caves varies from 5-40 meter, and the caves are characterised by both small passages and larger breakdown chambers. We relate the indirect geophysical measurements to parts of the known cave systems, and present structural models describing both geometry and groundwater flow in these caves with the help of numerical tools.

  2. Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

    PubMed

    Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

    2014-01-01

    Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

  3. On the palaeobiology of the extinct cave bear Ursus spelaeus ROSENMÜLLER. Insights from stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Grandal-D'Anglade, Aurora; Pérez-Rama, Marta; Fernández-Mosquera, Daniel

    2010-05-01

    Isotopic signatures (δ13C, δ15N) of bone collagen are used more and more to obtain the paleobiological data of fossil species. By means of these signatures, for example, the diet type of an extint species may be inferred. Also, the climate in which this species developed may greatly influence on the isotopic signature of its bone collagen. This influence is firstly produced in the initial material of the trophic chain but also may produce variations due to physiological changes caused by climatic changes in the species involved in this trophic chain. The cave bear (Ursus spelaeus ROSENMÜLLER) is a species of broad distribution in the European Pleistocene sites that has been studied from the isotopic point of view, trying to establish its diet type. For the moment, the results vary: though in most cases the isotopic values indicate a preferably herbivore diet type, differences exist between sites of different geographic zones and chronologies. Taking into account that climate influences on the cave bear's physiology through the physiological mechanism of hibernation, it is expected that in bears that lived in different climatic phases, the isotopic signatures will be also different. During hibernation a recycling of nitrogenised compounds is produced for protein synthesis, including bone collagen, so it is expected that the isotopic signature, at least of Nitrogen, will be altered with respect to the synthesized collagen when the bear is active and feeds normally. However, it is difficult to establish up to what extent the isotopic signatures due to hibernation or diet are overlapped. To study the physiological effect of hibernation on isotopic signatures we have selected bone remains of cave bears from populations whose chronologies correspond to different climatic moments, and in different ontogenetic stages, coming from Galician caves (NW of the Iberian Peninsula). Adult individuals show different isotopic signatures depending on their chronology. Juvenile

  4. The stratigraphy and formation history of fossil- and artefact-bearing sediments in the Milner Hall, Sterkfontein Cave, South Africa: New interpretations and implications for palaeoanthropology and archaeology

    NASA Astrophysics Data System (ADS)

    Stratford, Dominic; Grab, Stefan; Pickering, Travis Rayne

    2014-08-01

    The Sterkfontein palaeokarst deposits, the richest repository of Australopithecus fossils in the world, are currently divided into six members (M1-M6) and named the Sterkfontein Formation (Partridge and Watt, 1991). In this system, it was proposed that the passages and chambers deeper than the Silberberg Grotto formed most recently and are filled with comparatively young sediments from newer openings or reworked sediments from older, upper chambers. Here we describe the geomorphology, sedimentology, fauna and archaeological evidence from six deposits excavated near the base of the system in the Milner Hall. The use of a multidisciplinary approach enabled us to clarify the complex stratigraphic history, to track artefact-bearing deposits through multiple phases of deposition, and to identify an early deposit accumulated from the Silberberg Grotto to the base of the system. We propose that the Australopithecus-bearing Member 2 deposit originally extended down to near the base of the Milner Hall. We further propose that the vertical extent of the cave system was developed prior to the opening to the landscape surface, and that at that time the groundwater level was comparable to that seen now. We therefore argue that some of the earliest palaeoanthropological material in South Africa may have been deposited into the deepest chambers of the Sterkfontein Caves.

  5. Newly discovered fossil- and artifact-bearing deposits, uranium-series ages, and Plio-Pleistocene hominids at Swartkrans cave, South Africa.

    PubMed

    Sutton, Morris B; Pickering, Travis Rayne; Pickering, Robyn; Brain, C K; Clarke, Ronald J; Heaton, Jason L; Kuman, Kathleen

    2009-12-01

    We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previously unrealized artifact- and fossil-bearing deposits. These deposits underlie a speleothem dated by the uranium-thorium disequilibrium technique to 110,000+/-1,980 years old, the first tightly constrained, geochronological date available for the site. Recovered fauna from the two underlying deposits-including, prominently, the dental remains of Paranthropus (Australopithecus) robustus from the uppermost layer (Talus Cone Deposit)-indicate a significantly older, late Pliocene or early Pleistocene age for these units. The lowest unit (LB East Extension) is inferred to be an eastward extension of the well-known Lower Bank of Member 1, the earliest surviving infill represented at the site. The date acquired from the speleothem also sets the maximum age of a rich Middle Stone Age lithic assemblage.

  6. Geology of Caves.

    ERIC Educational Resources Information Center

    Davies, W. E.; Morgan, I. M.

    One of a series of general interest publications on science topics, the booklet provides those interested in the study of caves (speleology) with a nontechnical introduction to the subject. Separate sections examine types of caves, how caves form, cave features, minerals found in caves, uses of caves, and caves as natural underground laboratories.…

  7. CAVE WINDOW

    DOEpatents

    Levenson, M.

    1960-10-25

    A cave window is described. It is constructed of thick glass panes arranged so that interior panes have smaller windowpane areas and exterior panes have larger areas. Exterior panes on the radiation exposure side are remotely replaceable when darkened excessively. Metal shutters minimize exposure time to extend window life.

  8. Caving in the Classroom

    ERIC Educational Resources Information Center

    Yoder, Holly

    2010-01-01

    During Cave Week, more than 200 students explore a simulated cave environment and participate in cave-related activities. Active cavers from a local club bring in equipment and photos and speak about their caving experiences. As student groups explore the simulated cave, other groups participate in different activities where they can create bat…

  9. Gravity for Detecting Caves: Airborne and Terrestrial Simulations Based on a Comprehensive Karstic Cave Benchmark

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Sampietro, Daniele; Pivetta, Tommaso; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Rossi, Lorenzo; Fabbri, Julius; Mansi, Ahmed Hamdi

    2016-04-01

    Underground caves bear a natural hazard due to their possible evolution into a sink hole. Mapping of all existing caves could be useful for general civil usages as natural deposits or tourism and sports. Natural caves exist globally and are typical in karst areas. We investigate the resolution power of modern gravity campaigns to systematically detect all void caves of a minimum size in a given area. Both aerogravity and terrestrial acquisitions are considered. Positioning of the gravity station is fastest with GNSS methods the performance of which is investigated. The estimates are based on a benchmark cave of which the geometry is known precisely through a laser-scan survey. The cave is the Grotta Gigante cave in NE Italy in the classic karst. The gravity acquisition is discussed, where heights have been acquired with dual-frequency geodetic GNSS receivers and Total Station. Height acquisitions with non-geodetic low-cost receivers are shown to be useful, although the error on the gravity field is larger. The cave produces a signal of -1.5 × 10-5 m/s2, with a clear elliptic geometry. We analyze feasibility of airborne gravity acquisitions for the purpose of systematically mapping void caves. It is found that observations from fixed wing aircraft cannot resolve the caves, but observations from slower and low-flying helicopters or drones do. In order to detect the presence of caves the size of the benchmark cave, systematic terrestrial acquisitions require a density of three stations on square 500 by 500 m2 tiles. The question has a large impact on civil and environmental purposes, since it will allow planning of urban development at a safe distance from subsurface caves. The survey shows that a systematic coverage of the karst would have the benefit to recover the position of all of the greater existing void caves.

  10. Cave Rings

    DTIC Science & Technology

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...Literature The ‘splash ring’ conjecture is described in [5]. It is claimed that 45◦ is the most probable angle for secondary drops to be ejected at, and that...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by

  11. The Science of Exploring Caves.

    ERIC Educational Resources Information Center

    Reid, Frank S.

    1991-01-01

    An introduction to the science of speleology is presented. Discussed is why people explore caves--for the physical challenge, the thrill of discovery, and the joy of viewing their beauty. Cave conservation, cave biology, caving safety, and caving equipment are topics of discussion. A reading list on caves is included. (KR)

  12. Come to our Cave.

    ERIC Educational Resources Information Center

    Cassidy, Joan

    2001-01-01

    Describes an activity for first-grade students in which they learn about cave paintings and become spelunkers, or people who explore caves as a hobby, making their own paper head-lanterns. Explains that students draw animals on the walls of their "cave" (a dark hallway lined with brown kraft paper). (CMK)

  13. Conservation of prehistoric caves and stability of their inner climate: lessons from Chauvet and other French caves.

    PubMed

    Bourges, F; Genthon, P; Genty, D; Lorblanchet, M; Mauduit, E; D'Hulst, D

    2014-09-15

    In the last 150 years, some prehistoric painted caves suffered irreversible degradations due to misperception of conservation issues and subsequent mismanagement. These sites presented naturally an exceptional stability of their internal climate allowing conservation in situ of outstanding fragile remains, some for nearly 40,000 years. This is for a large part due to exchanges of air, CO2, heat and water with the karstic system in which these caves are included. We introduce the concept of underground confinement, based on the stability of the inner cave climate parameters, especially its temperature. Confined caves present the best conservative properties. It is emphasized that this confined state implies slow exchanges with the surrounding karst and that a stable cave cannot be viewed as a closed system. This is illustrated on four case studies of French caves of various confinement states evidenced by long term continuous monitoring and on strategies to improve their conservation properties. The Chauvet cave presents optimal conservation properties. It is wholly confined as shown by the stability of its internal parameters since its discovery in 1994. In Marsoulas cave, archeological works removed the entrance scree and let a strong opening situation of the decorated zone. Remediation is expected by adding a buffer structure at the entrance. In Pech Merle tourist cave, recurrent painting fading was related to natural seasonal drying of walls. Improvement of the cave closure system restored a confined state insuring optimal visibility of the paintings. In Gargas tourist cave, optimization of closures, lighting system and number of visitors, allowed it to gradually reach a semi-confined state that improved the conservation properties. Conclusions are drawn on the characterization of confinement state of caves and on the ways to improve their conservation properties by restoring their initial regulation mechanisms and to avoid threats to their stability.

  14. Geology of caves

    USGS Publications Warehouse

    Morgan, I.M.

    1991-01-01

    A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Occurring in a wide variety of rock types and caused by widely differing geological processes, caves range in size from single small rooms to intercorinecting passages many miles long. The scientific study of caves is called speleology (from the Greek words spelaion for cave and logos for study). It is a composite science based on geology, hydrology, biology, and archaeology, and thus holds special interest for earth scientists of the U.S. Geological Survey.

  15. Multidimensional GIS modeling of magnetic mineralogy as a proxy for fire use and spatial patterning: evidence from the Middle Stone Age bearing sea cave of Pinnacle Point 13B (Western Cape, South Africa).

    PubMed

    Herries, Andy I R; Fisher, Erich C

    2010-01-01

    This paper aims to identify the spatial patterning of burning and occupation within an early Middle Stone Age (MSA) sea cave in the Western Cape Province of South Africa by creating a multidimensional model of archaeomagnetic data recovered from all excavated units. Magnetic susceptibility and other mineral magnetic parameters are shown to provide an excellent proxy for the anthropogenic alteration and spread of burnt material into the surrounding unaltered cave deposits. The identification of combustion features and areas of occupation or different activities within the site can be determined because the movement of people throughout the cave mixes magnetically strong hearth material with magnetically weak unaltered sediments. This is also indicated by micromorphological analysis. The degree of enhancement is also shown to indicate the extent to which a deposit has been altered, and therefore, intensity of occupation, because multiple heatings of deposits are needed to form the concentrations of iron minerals occurring in some layers. This is further supported by a comparison with artifact density for the layers. Variation in the magnetic values between different areas of the site is noted with major occupation or fire building occurring in the front of the cave during earlier MIS 6 periods, while during later MIS 5 periods the entire cave is occupied intensively. The oldest, MIS 11 deposits at the rear of the cave indicate no evidence of enhancement and an apparent absence of any anthropogenic signature.

  16. Cave Water Studies.

    ERIC Educational Resources Information Center

    O'Keefe, Elizabeth S.

    1996-01-01

    Describes a comparative study project where seventh grade students tested water samples from 10 cave sites that had been tested 24 years ago in a study that had attempted to determine if pollution in the environment had reached cave water. Discusses lab skills and some results of the study. (JRH)

  17. Carroll Cave: a Missouri legend

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carroll Cave is one of the premiere caves of Missouri and the Ozarks region. At over 20 miles of surveyed passage, it is the 2nd longest cave in the state and 33rd longest in the nation. It is also the largest known cave formed in the Ordovician aged (443-485 million years ago) Gasconade Dolomite o...

  18. Morphogenesis of hypogenic caves

    NASA Astrophysics Data System (ADS)

    Klimchouk, Alexander

    2009-05-01

    Hypogenic speleogenesis is the formation of solution-enlarged permeability structures by waters ascending to a cave-forming zone from below in leaky confined conditions, where deeper groundwaters in regional or intermediate flow systems interact with shallower and more local groundwater flow systems. This is in contrast to more familiar epigenic speleogenesis which is dominated by shallow groundwater systems receiving recharge from the overlying or immediately adjacent surface. Hypogenic caves are identified in various geological and tectonic settings, formed by different dissolutional mechanisms operating in various lithologies. Despite these variations, resultant caves demonstrate a remarkable similarity in patterns and meso-morphology, which strongly suggests that the hydrogeologic settings were broadly identical in their formation. Hypogenic caves commonly demonstrate a characteristic suite of cave morphologies resulting from rising flow across the cave-forming zone with distinct buoyancy-dissolution components. In addition to hydrogeological criteria (hydrostratigraphic position, recharge-discharge configuration and flow pattern viewed from the perspective of the evolution of a regional groundwater flow system), morphogenetic analysis is the primary tool in identifying hypogenic caves. Cave patterns resulting from ascending transverse speleogenesis are strongly guided by the permeability structure in a cave formation. They are also influenced by the discordance of permeability structure in the adjacent beds and by the overall hydrostratigraphic arrangement. Three-dimensional mazes with multiple storeys, or complex 3-D cave systems are most common, although single isolated chambers, passages or crude clusters of a few intersecting passages may occur where fracturing is scarce and laterally discontinuous. Large rising shafts and collapse sinkholes over large voids, associated with deep hydrothermal systems, are also known. Hypogenic caves include many of the

  19. Ancient human footprints in Ciur-Izbuc Cave, Romania.

    PubMed

    Webb, David; Robu, Marius; Moldovan, Oana; Constantin, Silviu; Tomus, Bogdan; Neag, Ionel

    2014-09-01

    In 1965, Ciur-Izbuc Cave in the Carpathian Mountains of Romania was discovered to contain about 400 ancient human footprints. At that time, researchers interpreted the footprints to be those of a man, woman and child who entered the cave by an opening which is now blocked but which was usable in antiquity. The age of the prints (≈10-15 ka BP) was based partly on their association with cave bear (Ursus spelaeus) footprints and bones, and the belief that cave bears became extinct near the end of the last ice age. Since their discovery, the human and bear evidence and the cave itself have attracted spelunkers and other tourists, with the result that the ancient footprints are in danger of destruction by modern humans. In an effort to conserve the footprints and information about them and to reanalyze them with modern techiques, Ciur-Izbuc Cave was restudied in summer of 2012. Modern results are based on fewer than 25% of the originally described human footprints, the rest having been destroyed. It is impossible to confirm some of the original conclusions. The footprints do not cluster about three different sizes, and the number of individuals is estimated to be six or seven. Two cases of bears apparently overprinting humans help establish antiquity, and C-14 dates suggest a much greater age than originally thought. Unfortunately, insufficient footprints remain to measure movement variables such as stride length. However, detailed three-dimensional mapping of the footprints does allow a more precise description of human movements within the cave.

  20. Energy expenditure in caving.

    PubMed

    Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio; Rinaldi, Andrea C

    2017-01-01

    The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225-287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000-1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue.

  1. Energy expenditure in caving

    PubMed Central

    Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio

    2017-01-01

    The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225–287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000–1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue. PMID:28158208

  2. Bubble-induced cave collapse.

    PubMed

    Girihagama, Lakshika; Nof, Doron; Hancock, Cathrine

    2015-01-01

    Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon) physical contact with the cave walls or the aforementioned "natural" instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked) beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m). Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a "collapse". We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section), with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet), and the bubbles were produced using a syringe located at the cave floor.

  3. Bubble-Induced Cave Collapse

    PubMed Central

    Girihagama, Lakshika; Nof, Doron; Hancock, Cathrine

    2015-01-01

    Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon) physical contact with the cave walls or the aforementioned “natural” instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked) beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m). Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a “collapse”. We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section), with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet), and the bubbles were produced using a syringe located at the cave floor. PMID:25849088

  4. The evolution of cave systems from the surface to subsurface

    SciTech Connect

    Loucks, R.G.; Handford, C.R.

    1996-12-31

    Many carbonate reservoirs are the result of cave-forming processes. The origin and recognition of fractures, breccias, and sediment fills associated with paleocaves were determined through the study of modern and paleocaves systems. Cave formation and destruction are the products of near-surface processes. Near-surface processes include solutional excavation, clastic and chemical sedimentation, and collapse of cave walls and ceilings. Cave sediment is derived from inside and/or outside the system. Depositional mechanisms include suspension, tractional, mass-flow and rock-fall. Collapse of ceilings and walls from chaotic breakdown breccias. These piles can be tens of meters thick and contain large voids and variable amounts of matrix. Cave-roof crackle breccia forms from stress-and tension-related fractures in cave-roof strata. As the cave-bearing strata subside into the subsurface, mechanical compaction increases and restructures the existing breccias and remaining cavities. Fracture porosity increases and breccia and vug porosity decreases. Large cavities collapse forming burial chaotic breakdown breccias. Differentially compacted strata over the collapsed chamber fracture and form burial cave-roof crackle breccias. Continued burial leads to more extensive mechanical compaction causing previously formed clasts to fracture and pack closer together. The resulting product is a rebrecciated chaotic breakdown breccia composed predominantly of small clasts. Rebrecciated blocks are often overprinted by crackling. Subsurface paleocave systems commonly have a complex history with several episodes of fracturing and brecciation. The resulting collapsed-paleocave reservoir targets are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across.

  5. The evolution of cave systems from the surface to subsurface

    SciTech Connect

    Loucks, R.G. ); Handford, C.R. )

    1996-01-01

    Many carbonate reservoirs are the result of cave-forming processes. The origin and recognition of fractures, breccias, and sediment fills associated with paleocaves were determined through the study of modern and paleocaves systems. Cave formation and destruction are the products of near-surface processes. Near-surface processes include solutional excavation, clastic and chemical sedimentation, and collapse of cave walls and ceilings. Cave sediment is derived from inside and/or outside the system. Depositional mechanisms include suspension, tractional, mass-flow and rock-fall. Collapse of ceilings and walls from chaotic breakdown breccias. These piles can be tens of meters thick and contain large voids and variable amounts of matrix. Cave-roof crackle breccia forms from stress-and tension-related fractures in cave-roof strata. As the cave-bearing strata subside into the subsurface, mechanical compaction increases and restructures the existing breccias and remaining cavities. Fracture porosity increases and breccia and vug porosity decreases. Large cavities collapse forming burial chaotic breakdown breccias. Differentially compacted strata over the collapsed chamber fracture and form burial cave-roof crackle breccias. Continued burial leads to more extensive mechanical compaction causing previously formed clasts to fracture and pack closer together. The resulting product is a rebrecciated chaotic breakdown breccia composed predominantly of small clasts. Rebrecciated blocks are often overprinted by crackling. Subsurface paleocave systems commonly have a complex history with several episodes of fracturing and brecciation. The resulting collapsed-paleocave reservoir targets are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across.

  6. Egyptian Sea Cave

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    This brief article describes an archaeological expedition to the Red Sea coast area of Egypt in 2004. Kathryn Bard, an associate professor of archaeology at Boston University, along with her team, discovered the well-preserved cedar timbers of an ancient Egyptian seafaring vessel near the entrance to a large man-made cave. Limestone tablets with…

  7. The microbiology of Lascaux Cave.

    PubMed

    Bastian, F; Jurado, V; Nováková, A; Alabouvette, C; Saiz-Jimenez, C

    2010-03-01

    Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the former as a result of the biocide selection. The data show that fungi play an important role in the cave, and arthropods contribute to the dispersion of conidia. A careful study on the fungal ecology is needed in order to complete the cave food web and to control the black stains threatening the Paleolithic paintings.

  8. Morphological and speleothemic development in Brujas Cave (Southern Andean Range, Argentine): palaeoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Sancho, Carlos; Peña, José Luis; Mikkan, Raúl; Osácar, Cinta; Quinif, Yves

    2004-02-01

    Brujas Cave, in the Southern Andean Range, is a well-known endokarstic site in Argentina. However, the origin and evolution of this cave system are poorly known. Based on morphological cave features as well as characteristics of cave deposits, we propose a meteogene drawdown cave genesis, including a change from phreatic to vadose conditions related to the high rate of fluvial downcutting in the area. During the vadose period, various cave-related deposits, including authogenic calcite and gypsum speleothems, allogenic volcanic ash and external tufas were deposited. Gypsum crusts are the oldest cave deposits identified (90.2-64.3 ky BP). Their origin, deduced from isotopic characteristics ( ∂34S=9.6‰), is related to the oxidation of pyrite contained in the Jurassic limestone bedrock as well as the dissolution of overlying Jurassic-Triassic evaporite formations. Gypsum crust deposition is associated with evaporation of water flowing and seeping into the cave during arid environmental conditions. Calcite deposits precipitated from flowing water under equilibrium conditions represent the main speleothem growth period (67.6-34 ky BP in age). Their stable isotope values ( ∂13C=-3‰ to -5‰ and ∂18O=-9‰ to -11‰) may indicate slightly humid and warm conditions related to the regional Minchin lacustrine phase and global oxygen isotope stage 3. Following this stage, a seismic event is evidenced by accumulations of broken stalactites. Seepage calcite speleothems covering cave walls were deposited under disequilibrium conditions by evaporation, probably during Holocene time. Finally, another more recent gypsum deposition period represented by gypsum balls has been differentiated. Micromorphological as well as isotopic ( ∂34S=5.6‰) data indicate that these gypsum forms are related to cyclic processes (solution-deposition) from water seeping into the cave under arid conditions. In addition, intense volcanic activity in the area during Holocene time is deduced

  9. Environmental management of tourist caves

    NASA Astrophysics Data System (ADS)

    Cigna, A. A.

    1993-06-01

    In terms of the flow of energy or mass, caves may be nearly closed systems. From the perspective of environmental protection and tourist cave management there are three categories: (1) caves where the natural energy fluxes far exceed those created by visitors, with the consequence that their environmental parameters are not affected by development (e.g., caves subject to frequent flooding); (2) caves where natural and tourist energy fluxes are of similar magnitude, where environmental parameters respond to visitors but return to their natural equilibrium afterwards; and (3) caves where visitor fluxes far exceed the natural fluxes, so that natural environmental equilibrium may be destroyed. The aim of responsible management is to limit the introduced fluxes to those that will not destroy the natural equilibrium established in such parameters as temperature, relative humidity, CO2 concentration, etc. A visitor capacity criterion is defined, and measured effects of visitors are demonstrated at Grotte di Castellana and Grotta Grande del Vento, category 2 caves that are the principal tourist caves of Italy.

  10. Caves: A Course of Study.

    ERIC Educational Resources Information Center

    Phillips, Jan

    Middle school students from The College School, a private school in Webster Groves (Missouri) have completed a class called "Caves and Crystallography." A thematic approach was used in the course in which students and teachers read books telling how caves were formed, saw movies which explained the delicate balance of life underground,…

  11. Bony anomaly of Meckel's cave.

    PubMed

    Tubbs, R Shane; Salter, E George; Oakes, W Jerry

    2006-01-01

    This study describes the seemingly rare occurrence of bone formation within the proximal superior aspect of Meckel's cave thus forming a bony foramen for the proximal trigeminal nerve to traverse. The anatomy of Meckel's cave is reviewed and the clinical potential for nerve compression from this bony anomaly discussed.

  12. Meningiomas of Meckel's cave.

    PubMed

    Delfini, R; Innocenzi, G; Ciappetta, P; Domenicucci, M; Cantore, G

    1992-12-01

    A series of 16 patients with meningiomas of Meckel's cave is reported. Trigeminal neuralgia, typical or atypical, was the initial symptom in 10 patients (62.5%). At admission, trigeminal signs and symptoms were present in 15 patients (93.7%); in 7 patients (43.7%), trigeminal dysfunction was combined with the impairment of other cranial nerves. On retrospective analysis, these patients fall into two clinical groups that differ also in prognosis. Group 1 comprises eight patients with trigeminal signs and symptoms only. These patients had small meningiomas strictly affecting Meckel's cave. Total removal of the tumor was achieved in seven of eight patients, without adjunctive postoperative neurological deficits. In this group, there were no tumor recurrences. Group 2 comprises the other eight patients in whom trigeminal dysfunction was combined with impairment of other cranial nerves. These patients had large tumors arising from Meckel's cave and secondarily invading the cavernous sinus (five patients) or extending into the posterior fossa (two patients) or largely growing into the middle fossa (one patient). Total removal was achieved in only one patient, and a worsening of the preoperative neurological status was observed in four patients; there were three cases of tumor progression. A subtemporal intradural approach (used in the past in every case) is still used for the small tumors of Group 1 with good results. Since 1985, for tumors involving the cavernous sinus, we have employed a frontotemporal craniotomy with extradural clinoidectomy and superior and lateral approach to the cavernous sinus. When the tumor extends toward the posterior fossa, we use a combined temporosuboccipital-transpetrosal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Survey and hydrogeology of Carroll Cave

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carroll Cave, located in Camden County, Missouri, is the largest known cave formed in the Gasconade Dolomite of the Salem Plateau. Despite extensive visitation over the last 50 years and multiple survey efforts, a comprehensive map of the cave has never been produced. In 2002, the Carroll Cave Conse...

  14. Ecomorphological convergence of cave communities.

    PubMed

    Trontelj, Peter; Blejec, Andrej; Fišer, Cene

    2012-12-01

    Extreme selective environments are commonly believed to funnel evolution toward a few predictable outcomes. Caves are well-known extreme environments with characteristically adapted faunas that are similar in appearance, physiology, and behavior all over the world, even if not closely related. Morphological diversity between closely related cave species has been explained by difference in time since colonization and different ecological influence from the surface. Here, we tested a more classical hypothesis: morphological diversity is niche-based, and different morphologies reflect properties of microhabitats within caves. We analyzed seven communities with altogether 30 species of the subterranean amphipod (crustacean) genus Niphargus using multivariate morphometrics, multinomial logit models cross-validation, and phylogenetic reconstruction. Species clustered into four distinct ecomorph classes-small pore, cave stream, cave lake, and lake giants-associated with specific cave microhabitats and of multiple independent phylogenetic origins. Traits commonly regarded as adaptations to caves, such as antenna length, were shown to be related to microhabitat parameters, such as flow velocity. These results demonstrate that under the selection pressure of extreme environment, the ecomorphological structure of communities can converge. Thus, morphological diversity does not result from adaptive response to temporal and ecological gradients, but from fine-level niche partitioning.

  15. Late Pleistocene leopards across Europe - northernmost European German population, highest elevated records in the Swiss Alps, complete skeletons in the Bosnia Herzegowina Dinarids and comparison to the Ice Age cave art

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2013-09-01

    European leopard sites in Europe demonstrate Early/Middle Pleistocene out of Africa lowland, and Late Pleistocene Asian alpine migrations being driven by climatic changes. Four different European Pleistocene subspecies are known. The final European Late Pleistocene “Ice Age leopard” Panthera pardus spelaea (Bächler, 1936) is validated taxonomically. The skull shows heavy signs of sexual dimorphism with closest cranial characters to the Caucasian Panthera pardus ciscaucasica (Persian leopard). Late Pleistocene leopards were distributed northernmost, up to S-England with the youngest stratigraphic records by skeletons and cave art in the MIS 2/3 (about 32,000-26,000 BP). The oldest leopard painting left by Late Palaeolithics (Aurignacians/Gravettians) in the Chauvet Cave (S-France) allows the reconstruction of the Ice Age leopard fur spot pattern being close to the snow or Caucasian leopards. The last Ice Age glacial leopard habitat was the mountain/alpine boreal forest (not mammoth steppe lowland), where those hunted even larger prey such as alpine game (Ibex, Chamois). Into some lairs, those imported their prey by short-term cave dwelling (e.g. Baumann's Cave, Harz Mountains, Germany). Only Eurasian Ice Age leopards specialized, similar as other Late Pleistocene large felids (steppe lions), on cave bear predation/scavenging partly very deep in caves. In Vjetrenica Cave (Dinarid Mountains, Bosnia Herzegovina), four adult leopards (two males/two females) of the MIS 3 were found about two km deep from the entrance in a cave bear den, near to one cave bear skeleton, that remained articulated in its nest. Leopards died there, partly being trapped by raising water levels of an active ponor stream, but seem to have been killed possibly either, similar as for lions known, in battles with cave bears in several cave bear den sites of Europe (e.g. Baumann's Cave, Wildkirchli Cave, Vjetrenica Cave). At other large cave sites, with overlap of hyena, wolf and dhole dens at

  16. Winter distribution and use of high elevation caves as foraging sites by the endangered Hawaiian hoary bat, Lasiurus cinereus semotus

    USGS Publications Warehouse

    Bonaccorso, Frank; Montoya-Aiona, Kristina; Pinzari, Corinna A.; Todd, Christopher M.

    2016-01-01

    We examine altitudinal movements involving unusual use of caves by Hawaiian hoary bats, Lasiurus cinereus semotus, during winter and spring in the Mauna Loa Forest Reserve (MLFR), Hawai‘i Island. Acoustic detection of hoary bat vocalizations, were recorded with regularity outside 13 lava tube cave entrances situated between 2,200 to 3,600 m asl from November 2012 to April 2013. Vocalizations were most numerous in November and December with the number of call events and echolocation pulses decreasing through the following months. Bat activity was positively correlated with air temperature and negatively correlated with wind speed. Visual searches found no evidence of hibernacula nor do Hawaiian hoary bats appear to shelter by day in these caves. Nevertheless, bats fly deep into caves as evidenced by numerous carcasses found in cave interiors. The occurrence of feeding buzzes around cave entrances and visual observations of bats flying in acrobatic fashion in cave interiors point to the use of these spaces as foraging sites. Peridroma moth species (Noctuidae), the only abundant nocturnal, flying insect sheltering in large numbers in rock rubble and on cave walls in the MLFR, apparently serve as the principal prey attracting hoary bats during winter to lava tube caves in the upper MLFR. Caves above 3,000 m on Mauna Loa harbor temperatures suitable for Pseudogymnoascus destructansfungi, the causative agent of White-nose Syndrome that is highly lethal to some species of North American cave-dwelling bats. We discuss the potential for White-nose Syndrome to establish and affect Hawaiian hoary bats.

  17. Meningiomas of Meckel's cave.

    PubMed

    Nijensohn, D E; Araujo, J C; MacCarty, C S

    1975-08-01

    A retrospective review of 12 cases of meningioma of Meckel's cave involving the Gasserian ganglion or the trigeminal posterior root (or both) seen at the Mayo Clinic during a 20-year period suggested three clearly defined clinical groups. One group (the largest) had typical trigeminal neuralgia and an excellent prognosis after the removal of the easily detachable mass that was impinging on the ganglion. A second group, with meningiomas en plaque embedded in the ganglion, had a history of atypical trigeminal face pain without neurological deficit, but the prognosis for pain relief was not as good as in the previous group. A third group had a history of face dysesthesias and pain, objective trigeminal sensory loss, and multiple cranial nerve deficit; these patients had meningiomas with histological signs of mitotic activity and a poor prognosis, with return of intractable pain and recurrence of the tumor.

  18. Steppe lion remains imported by Ice Age spotted hyenas into the Late Pleistocene Perick Caves hyena den in northern Germany

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2009-05-01

    Upper Pleistocene remains of the Ice Age steppe lion Panthera leo spelaea (Goldfuss, 1810) have been found in the Perick Caves, Sauerland Karst, NW Germany. Bones from many hyenas and their imported prey dating from the Lower to Middle Weichselian have also been recovered from the Perick Cave hyena den. These are commonly cracked or exhibit deep chew marks. The absence of lion cub bones, in contrast to hyena and cave bear cub remains in the Perick Caves, and other caves of northern Germany, excludes the possibility that P. leo spelaea used the cave for raising cubs. Only in the Wilhelms Cave was a single skeleton of a cub found in a hyena den. Evidence of the chewing, nibbling and cracking of lion bones and crania must have resulted from the importation and destruction of lion carcasses (4% of the prey fauna). Similar evidence was preserved at other hyena den caves and open air sites in Germany. The bone material from the Perick and other Central European caves points to antagonistic hyena and lion conflicts, similar to clashes of their modern African relatives.

  19. New Results on the Palaeobiology of Bears on the Swabian Alb (Chronology, Isotopic Geochemistry and Palaeogenetics)

    NASA Astrophysics Data System (ADS)

    Muenzel, Susanne

    2010-05-01

    Paleogenetic investigations at three geographically close caves in the Ach Valley near Blaubeuren have revealed two different cave bear haplogroups. These two haplogroups correspond to Ursus spelaeus (haplogroup 1) and Ursus ingressus (haplogroup 4) (Rabeder & Hofreiter 2004, Die Höhle 55, 58-77). This genetic variability was first attested for Geißenklösterle and Sirgenstein cave, but the new genetic data attest them also for Hohle Fels. In all three caves Ursus ingressus replaced Ursus spelaeus around 28 000 B.P. The carbon and nitrogen isotopes of the two genetic types do not vary significantly, meaning that there is no dietary difference between them and Ursus spelaeus were in dietary competition with Ursus ingressus in the Ach valley. The radiocarbon dates suggested a sudden replacement (Hofreiter et al. 2007, Current Biology 17(4): R1-R3), which must have been accompanied by local extinction of the older cave bear, according to the dietary competition with the younger bear. The possible reasons for this replacement are not clear yet. Climatic changes are unlikely, since the faunal composition remains the same and the environmental data do not differ significantly. But we cannot exclude human impact on the cave bear population, since a cave bear vertebra with an embedded fragment of a flint projectile was recovered in the Gravettian layer AH IIcf dated to 27 830+150-140 B.P. and gives indisputable proof of the hunting of cave bears. Numerous cut marks proof an ongoing exploitation of this species. In this context, new radiocarbon dates and isotopic results on cave bears and coeval brown bears will help us to refine the possible scenarios of this complex evolutionary and ecological process. These results will be used to test hypotheses of competitive exclusion between the different bear species. This study will exemplify how combining evidence from different approaches can provide invaluable clues about palaeobiology of late Pleistocene large mammals such as

  20. Cave development by frost weathering

    NASA Astrophysics Data System (ADS)

    Oberender, Pauline; Plan, Lukas

    2015-01-01

    This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50 m and entrances can be more than 100 m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2 m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5 g/month of debris could be collected, but a few 100 g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

  1. 39 CFR 501.3 - Postage Evidencing System provider qualification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.3 Postage Evidencing System provider qualification. Any person or entity seeking authorization to manufacture and/or distribute Postage Evidencing Systems... 39 Postal Service 1 2010-07-01 2010-07-01 false Postage Evidencing System provider...

  2. 39 CFR 501.2 - Postage Evidencing System provider authorization.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.2 Postage Evidencing System provider authorization... approval of the Postal Service: (1) Producing or distributing any Postage Evidencing System that generates... 39 Postal Service 1 2010-07-01 2010-07-01 false Postage Evidencing System provider...

  3. 39 CFR 501.10 - Postage Evidencing System modifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.10 Postage Evidencing System modifications. (a) An... 39 Postal Service 1 2010-07-01 2010-07-01 false Postage Evidencing System modifications. 501.10... a previously approved Postage Evidencing System. The notification must include a summary of...

  4. 39 CFR 501.17 - Decertified Postage Evidencing Systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.17 Decertified Postage Evidencing Systems. (a) A Decertified Postage Evidencing System is a device for which the provider's authority to distribute has been... 39 Postal Service 1 2010-07-01 2010-07-01 false Decertified Postage Evidencing Systems....

  5. 39 CFR 501.3 - Postage Evidencing System provider qualification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Postage Evidencing System provider qualification... MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.3 Postage Evidencing System provider qualification. Any person or entity seeking authorization to manufacture and/or distribute Postage Evidencing...

  6. Exploring old caves

    NASA Astrophysics Data System (ADS)

    Luana Belli, Maria

    2015-04-01

    Quarries, caves and mines often contain fossils. During the '30s in Rome, the urban expansion needs for building materials such as gravel, sand and clay were extracted from quarries that surrounded the city. One of these quarries in particular, in the area of Saccopastore (Nomentana area 3 km from the University Sapienza Roma) returned an ancient human fossil skull belonging to a Neanderthal (most likely a female) who lived in Latium about 120,000 years ago. Detailed studies of this fossil were carried out by Sergio Sergi, the son of the founder of the Museum of Anthropology in Rome, Giuseppe Sergi. The museum was founded in 1884 and was later transferred to the University City (1934) where it is still located. Professor Maria Luana Belli, a science teacher in the Liceo Scientifico "G. Keplero" is a volunteer and collaborator with the Museum "G. Sergi", and she and her students retrace the places of the discovery on the trail of the Neanderthals, for understanding the evolution of the territory in a perspective of interdisciplinary teaching.

  7. Summit firn caves, mount rainier, washington.

    PubMed

    Kiver, E P; Mumma, M D

    1971-07-23

    Heat and steam from the crater fumaroles have melted over 5700 feet (1737 meters) of cave passage in the ice-filled east crater of Mount Rainier. The caves are in approximate balance with the present geothermal heat release. Future changes in the thermal activity of the summit cone will cause corresponding changes in cave passage dimensions, location, and ceiling and wall ablation features.

  8. Cave Art: Reflections of Early Human Culture.

    ERIC Educational Resources Information Center

    Sullivan, Brother Nicholas

    1981-01-01

    Discusses Paleolithic and Neolithic cave art and artifacts, stressing the degree of intellectual ability exhibited by the creators of this art. Topics discussed include some misunderstandings about cave art intellect shown by cave artists and the use of light and color. (DS)

  9. Fish Assemblages of Mediterranean Marine Caves

    PubMed Central

    Bussotti, Simona; Di Franco, Antonio; Francour, Patrice; Guidetti, Paolo

    2015-01-01

    Fish assemblages associated with 14 marine caves and adjacent external rocky reefs were investigated at four Marine Protected Areas (MPAs) along the coasts of Italy. Within the caves sampling was carried out in different sub-habitats: walls, ceilings, bottoms and ends of caves. On the whole, 38 species were recorded inside the 14 caves investigated. Eighteen species were exclusively found inside the caves: they were mainly represented by speleophilic (i.e. species preferentially or exclusively inhabiting caves) gobids (e.g. Didogobius splechtnai) and nocturnal species (e.g. Conger conger). Forty-one species were censused outside, 20 of which were shared with cave habitats. Apogon imberbis was the most common fish found in all 14 caves investigated, followed by Thorogobius ephippiatus (recorded in 13 caves), and Diplodus vulgaris and Scorpaena notata (both censused in 12 caves). Distinct fish assemblages were found between external rocky reefs and the different cave sub-habitats. New data on the distribution of some speleophilic gobids were collected, showing the existence of a pool of species shared by marine caves on a large scale (i.e. hundreds of km). Considering the uniqueness of cave fishes (18 exclusive species and different assemblage structures), the inclusion of marine caves among the habitats routinely investigated for fish biodiversity monitoring could facilitate the achievement of more comprehensive inventories. Due to their contribution to local species diversity and the shelter they provide to species valuable for conservation, marine caves should be prioritized for their inclusion not only within future MPAs through the Mediterranean Sea, but also into larger management spatial planning. PMID:25875504

  10. A Cave of Our Own.

    ERIC Educational Resources Information Center

    Colegate, Carol; Smith, Janice

    1995-01-01

    Describes an activity that involves exploring a model cave made out of a two-person tent as a way to add science process to a thematic unit on bats and spiders. This multifunctional learning center provides students with a variety of hands-on experiences, helps students focus on observable things from nature, and emphasizes process skills. Lists…

  11. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Confidentiality of cave... AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a) Information... location of a significant cave or a cave nominated for designation, unless the authorized...

  12. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Confidentiality of cave... AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a) Information... location of a significant cave or a cave nominated for designation, unless the authorized...

  13. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Confidentiality of cave... AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a) Information... location of a significant cave or a cave nominated for designation, unless the authorized...

  14. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Confidentiality of cave... AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a) Information... location of a significant cave or a cave nominated for designation, unless the authorized...

  15. 76 FR 42654 - Endangered and Threatened Wildlife and Plants; Petition To List Grand Canyon Cave Pseudoscorpion

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ... Grand Canyon cave scorpion) was in that group of 67 species. Based on the evaluation of the information..., or stinger, that true scorpions possess. The specimen of Grand Canyon cave pseudoscorpion, when... Cave, Middle Cave, Scorpion Cave, Tse An Cho Cave, Tuning Fork Cave, and Cave of the Domes. All...

  16. Short and Long Term Environmental Trends Observed in the Magnetism of Cave Deposits

    NASA Astrophysics Data System (ADS)

    Feinberg, Joshua

    2016-04-01

    Caves are deep time archives of environmental conditions at the surface. Traditional paleoclimate proxies, such as oxygen and carbon isotopic ratios, are preserved within actively growing carbonate speleothems and can be constrained in time using high-resolution 230Th geochronology. While these isotopic speleothem proxies have revolutionized paleoclimate studies, here we discuss a promising new development in speleothem studies: the use of magnetic measurements to constrain changes in the flux of Fe-bearing minerals (their composition, concentration, and magnetic grain size distribution) within the context of environmental change. Fe-bearing minerals can occur within speleothems due to a variety of transportation and nucleation & growth mechanisms. Drip waters carry trace concentrations of Fe-bearing minerals from overlying soils and dissolved and eroded bedrock. Flood waters that temporarily fill a cave passage will leave behind thin films of silt- and clay-sized sediment, some of which contain Fe-bearing minerals. Some minerals, such as goethite, are thought to nucleate and grow in pore spaces in the overlying rock and can become deposited via dripwater onto actively growing stalagmites. Alternatively, changes in the Eh and pH conditions of groundwater as it equilibrates with the open air environment of a cave may cause dissolved Fe to nucleate and grow goethite directly on the surface of carbonate speleothems. Thus, while the incorporation of Fe-bearing minerals into speleothems is primarily a function of surface environmental conditions, including precipitation patterns, mean annual temperature, and pedogenic productivity, secondary processes within a cave environment can also contribute to Fe-minerals in speleothems. Here we present some promising examples of how the magnetic properties of Fe-bearing minerals preserved within speleothems can provide environmental information on short (e.g., decadal) and long (e.g., millennial) timescales that is independent

  17. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a) Information... harm, theft, or destruction to cave resources. (b) Requesting confidential information. Notwithstanding... Federal or State governmental agencies, bona fide educational or research institutes, or individuals...

  18. Paleobiological Implications of the Isotopic Signatures ( 13C, 15N) of Fossil Mammal Collagen in Scladina Cave (Sclayn, Belgium)

    NASA Astrophysics Data System (ADS)

    Bocherens, Hervé; Billiou, Daniel; Patou-Mathis, Marylène; Bonjean, Dominique; Otte, Marcel; Mariotti, André

    1997-11-01

    An isotopic investigation of upper Pleistocene mammal bones and teeth from Scladina cave (Sclayn, Belgium) demonstrated the very good quality of collagen preservation. A preliminary screening of the samples used the amount of nitrogen in whole bone and dentine in order to estimate the preserved amount of collagen before starting the extraction process. The isotopic abundances of fossil specimens from still-extant species are consistent with their trophic position. Moreover, the 15N isotopic abundance is higher in dentine than in bone in bears and hyenas, a phenomenon already observed in modern specimens. These results demonstrate that the isotopic compositions of samples from Scladina cave can be interpreted in ecological terms. Mammoths exhibit a high 15N isotopic abundance relative to other herbivores, as was the case in Siberian and Alaskan samples. These results suggest distinctive dietary adaptations in herbivores living in the mammoth steppe. Cave bears are clearly isotopically different from coeval brown bears, suggesting an ecological separation between species, with a pure vegetarian diet for cave bear and an omnivorous diet for brown bear.

  19. From Cave Walls to Clay Images

    ERIC Educational Resources Information Center

    Stone, Julie

    2004-01-01

    About 15,000 BC, the bison and other animals roamed the land and cave people, in their spare time, found colorful, chalky rocks with which to play. Over the course of time, they found that the chalky rocks would rub off on the cave walls, thus cave paintings and the pursuit of art was born. This article describes one fourth-grade classroom's…

  20. Computer Assisted Virtual Environment - CAVE

    SciTech Connect

    Erickson, Phillip; Podgorney, Robert; Weingartner, Shawn; Whiting, Eric

    2014-01-14

    Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

  1. Computer Assisted Virtual Environment - CAVE

    ScienceCinema

    Erickson, Phillip; Podgorney, Robert; Weingartner, Shawn; Whiting, Eric

    2016-07-12

    Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

  2. Candidate Cave Entrances on Mars

    NASA Astrophysics Data System (ADS)

    Cushing, Glen

    2012-04-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visiblewavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  3. Candidate cave entrances on Mars

    USGS Publications Warehouse

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  4. Bacteria, fungi and biokarst in Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    NASA Astrophysics Data System (ADS)

    Cunningham, K. I.; Northup, D. E.; Pollastro, R. M.; Wright, W. G.; Larock, E. J.

    1995-02-01

    Lechuguilla Cave is a deep, extensive, gypsumand sulfur-bearing hypogenic cave in Carlsbad Caverns National Park, New Mexico, most of which (>90%) lies more than 300 m beneath the entrance. Located in the arid Guadalupe Mountains, Lechuguilla's remarkable state of preservation is partially due to the locally continuous Yates Formation siltstone that has effectively diverted most vadose water away from the cave. Allocthonous organic input to the cave is therefore very limited, but bacterial and fungal colonization is relatively extensive: (1) Aspergillus sp. fungi and unidentified bacteria are associated with iron-, manganese-, and sulfur-rich encrustations on calcitic folia near the suspected water table 466 m below the entrance; (2) 92 species of fungi in 19 genera have been identified throughout the cave in oligotrophic (nutrient-poor) “soils” and pools; (3) cave-air condensate contains unidentified microbes; (4) indigenous chemoheterotrophic Seliberius and Caulobacter bacteria are known from remote pool sites; and (5) at least four genera of heterotrophic bacteria with population densities near 5×105 colony-forming units (CFU) per gram are present in ceiling-bound deposits of supposedly abiogenic condensation-corrosion residues. Various lines of evidence suggest that autotrophic bacteria are present in the ceiling-bound residues and could act as primary producers in a unique subterranean microbial food chain. The suspected autotrophic bacteria are probably chemolithoautotrophic (CLA), utilizing trace iron, manganese, or sulfur in the limestone and dolomitic bedrock to mechanically (and possibly biochemically) erode the substrate to produce residual floor deposits. Because other major sources of organic matter have not been detected, we suggest that these CLA bacteria are providing requisite organic matter to the known heterotrophic bacteria and fungi in the residues. The cavewide bacterial and fungal distribution, the large volumes of corrosion residues

  5. Modeling and analysis of caves using voxelization

    NASA Astrophysics Data System (ADS)

    Szeifert, Gábor; Szabó, Tivadar; Székely, Balázs

    2014-05-01

    Although there are many ways to create three dimensional representations of caves using modern information technology methods, modeling of caves has been challenging for researchers for a long time. One of these promising new alternative modeling methods is using voxels. We are using geodetic measurements as an input for our voxelization project. These geodetic underground surveys recorded the azimuth, altitude and distance of corner points of cave systems relative to each other. The diameter of each cave section is estimated from separate databases originating from different surveys. We have developed a simple but efficient method (it covers more than 99.9 % of the volume of the input model on the average) to convert these vector-type datasets to voxels. We have also developed software components to make visualization of the voxel and vector models easier. Since each cornerpoint position is measured relative to another cornerpoints positions, propagation of uncertainties is an important issue in case of long caves with many separate sections. We are using Monte Carlo simulations to analyze the effect of the error of each geodetic instrument possibly involved in a survey. Cross-sections of the simulated three dimensional distributions show, that even tiny uncertainties of individual measurements can result in high variation of positions that could be reduced by distributing the closing errors if such data are available. Using the results of our simulations, we can estimate cave volume and the error of the calculated cave volume depending on the complexity of the cave. Acknowledgements: the authors are grateful to Ariadne Karst and Cave Exploring Association and State Department of Environmental and Nature Protection of the Hungarian Ministry of Rural Development, Department of National Parks and Landscape Protection, Section Landscape and Cave Protection and Ecotourism for providing the cave measurement data. BS contributed as an Alexander von Humboldt Research

  6. 49 CFR 215.115 - Defective roller bearing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by—...

  7. 49 CFR 215.115 - Defective roller bearing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by—...

  8. 49 CFR 215.115 - Defective roller bearing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by—...

  9. 49 CFR 215.115 - Defective roller bearing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by—...

  10. 49 CFR 215.115 - Defective roller bearing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by—...

  11. Management issues in a Tasmanian tourist cave: potential microclimatic impacts of cave modifications.

    PubMed

    Russell, Mick J; MacLean, Victoria L

    2008-05-01

    Caves can be difficult to navigate and often require physical modification to allow easy access for visitors. Single entrance caves double the access impact of each visitor. Visitors in tourist caves have direct physical effects such as the introduction of concrete and steel structures; transport of mud, dust, and nutrients; installation of lights and the exhalation of water vapour and carbon dioxide into the air. Indirect physical effects include alteration of the microclimate, both through physical modifications that change the ventilation regime and through the presence of visitors leading to changes in temperature, humidity and CO2 within the cave environment. Anthropomorphic changes to cave physical environments to aid access or to reduce backtracking can have adverse effects on the internal microclimate of cave systems with subsequent changes to the cave environment affecting the quality of decorations and cave art and the diversity of cave fauna. Although often stated that caves operate at or near a constant temperature, closer examination indicates that cave temperatures are neither static nor constant. The degree of variation depends largely on the structure and physical characteristics of the cave. Air temperature and humidity gradients between the inside and outside cave environment can result in air density differences, which create airflow, which will in turn affect the cave microclimate. As part of the development of a management framework for King Solomons Cave, Tasmania, a study of the microclimate was carried out on behalf of Tasmanian Parks and Wildlife Service. Analysis of the variables showed significant differences in air temperature within each site and between sites. These differences range from 4 degrees C variation at one site to 0 degrees C at another site. The data were used to model potential airflow between the cave and the external environment. Results indicate that part of the cave is dominated by airflow between the chimney and the

  12. Magnetostratigraphy of sediments in mammoth cave, kentucky.

    PubMed

    Schmidt, V A

    1982-08-27

    Clastic sediment deposits found within the caves of Mammoth Cave National Park have yielded a magnetostratigraphic pattern of magnetic polarity reversals which indicates-that they were deposited over a range of at least 1 million and most likely 2 million years.

  13. Magnetostratigraphy of Sediments in Mammoth Cave, Kentucky

    NASA Astrophysics Data System (ADS)

    Schmidt, Victor A.

    1982-08-01

    Clastic sediment deposits found within the caves of Mammoth Cave National Park have yielded a magnetostratigraphic pattern of magnetic polarity reversals which indicates that they were deposited over a range of at least 1 million and most likely 2 million years.

  14. [Anatomic variants of Meckel's cave on MRI].

    PubMed

    Benoudiba, F; Hadj-Rabia, M; Iffenecker, C; Fuerxer, F; Bekkali, F; Francke, J P; Doyon, D

    1998-10-01

    Magnetic resonance imaging (MRI) gives an accurate analysis of Meckel's cave variability. Images were acquired in 50 patients with several sections for anatomical comparison. Using several sections, MRI is a suitable method for better analysis of the trigeminal cistern. The most frequent findings are symmetrical trigeminal cisterns. Expansion of Meckel's cave or its disappearance has pathological significance.

  15. Cavernous hemangioma of Meckel's cave. Case report.

    PubMed

    Fehlings, M G; Tucker, W S

    1988-04-01

    A case of a cavernous hemangioma located within Meckel's cave and involving the gasserian ganglion is described in a patient presenting with facial pain and a trigeminal nerve deficit. Although these lesions have been reported to occur in the middle fossa, this is believed to be the first case of such a vascular malformation arising solely from within Meckel's cave.

  16. Microbiological and environmental issues in show caves.

    PubMed

    Saiz-Jimenez, Cesareo

    2012-07-01

    Cultural tourism expanded in the last half of the twentieth century, and the interest of visitors has come to include caves containing archaeological remains. Some show caves attracted mass tourism, and economical interests prevailed over conservation, which led to a deterioration of the subterranean environment and the rock art. The presence and the role of microorganisms in caves is a topic that is often ignored in cave management. Knowledge of the colonisation patterns, the dispersion mechanisms, and the effect on human health and, when present, over rock art paintings of these microorganisms is of the utmost importance. In this review the most recent advances in the study of microorganisms in caves are presented, together with the environmental implications of the findings.

  17. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.12 Confidentiality of cave location information. (a) Information...

  18. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.12 Confidentiality of cave location information. (a) Information...

  19. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.12 Confidentiality of cave location information. (a) Information...

  20. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.12 Confidentiality of cave location information. (a) Information...

  1. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.12 Confidentiality of cave location information. (a) Information...

  2. Next generation phylogeography of cave and surface Astyanax mexicanus.

    PubMed

    Coghill, Lyndon M; Darrin Hulsey, C; Chaves-Campos, Johel; García de Leon, Francisco J; Johnson, Steven G

    2014-10-01

    The loss of traits is a commonly observed evolutionary pattern in cave organisms, but due to extensive morphological convergence, inferring relationships between cave and surface populations can be difficult. For instance, Astyanax mexicanus (the blind Mexican cavefish) is thought to have repeatedly lost its eyes following colonization of cave environments, but the number of evolutionarily independent invasions of this species into caves remains unclear. Because of these repeated losses, it has become a model organism for studying the genetic basis of phenotypic trait loss. Here we reconstruct a high-resolution phylogeography for A. mexicanus inferred from both mitochondrial DNA and several thousand single nucleotide polymorphisms. We provide novel insight into the origin of cave populations from the Sabinos and Río Subterráneo caves and present evidence that the Sabinos cave population is part of a unique cave lineage unrelated to other A. mexicanus cave populations. Our results indicate A. mexicanus cave populations have at least four independent origins.

  3. Does the Cave Environment Reduce Functional Diversity?

    PubMed Central

    Fernandes, Camile Sorbo; Batalha, Marco Antonio; Bichuette, Maria Elina

    2016-01-01

    Caves are not colonised by all taxa present in the surface species pool, due to absence of light and the tendency to food limitation when compared to surface communities. Under strong species sorting during colonisation and later by the restrictive environmental filter, traits that are not adaptive in subterranean habitats may be filtered out. We tested whether cave communities were assembled by the restrictive regime propitiated by permanent darkness or by competitive exclusion due to resource scarcity. When compared to surface communities, the restrictive subterranean regime would lead to lower functional diversity and phenotypic clustering inside the caves, and the opposite should be expected in the case of competitive exclusion. Using isopods (Oniscidea) as model taxa, we measured several niche descriptors of taxa from surface and cave habitats, used a multivariate measure of functional diversity, and compared their widths. We found phenotypic overdispersion and higher functional diversity in cave taxa when compared to surface taxa. On the one hand, the dry climate outside of caves hampered the survival of several taxa and their ecological strategies, not viable under severe desiccation risk, culminating in the clustering of functional traits. In contrast, this restriction does not occur inside of caves, where isopods find favourable conditions under lower predation pressures and more amenable environmental parameters that allow occupation and subsequent diversification. Our results showed that, at least for some taxa, caves may not be such a harsh environment as previously thought. The high functional diversity we found inside caves adds an additional reason for the conservation of these sensitive environments. PMID:27003837

  4. Does the Cave Environment Reduce Functional Diversity?

    PubMed

    Fernandes, Camile Sorbo; Batalha, Marco Antonio; Bichuette, Maria Elina

    2016-01-01

    Caves are not colonised by all taxa present in the surface species pool, due to absence of light and the tendency to food limitation when compared to surface communities. Under strong species sorting during colonisation and later by the restrictive environmental filter, traits that are not adaptive in subterranean habitats may be filtered out. We tested whether cave communities were assembled by the restrictive regime propitiated by permanent darkness or by competitive exclusion due to resource scarcity. When compared to surface communities, the restrictive subterranean regime would lead to lower functional diversity and phenotypic clustering inside the caves, and the opposite should be expected in the case of competitive exclusion. Using isopods (Oniscidea) as model taxa, we measured several niche descriptors of taxa from surface and cave habitats, used a multivariate measure of functional diversity, and compared their widths. We found phenotypic overdispersion and higher functional diversity in cave taxa when compared to surface taxa. On the one hand, the dry climate outside of caves hampered the survival of several taxa and their ecological strategies, not viable under severe desiccation risk, culminating in the clustering of functional traits. In contrast, this restriction does not occur inside of caves, where isopods find favourable conditions under lower predation pressures and more amenable environmental parameters that allow occupation and subsequent diversification. Our results showed that, at least for some taxa, caves may not be such a harsh environment as previously thought. The high functional diversity we found inside caves adds an additional reason for the conservation of these sensitive environments.

  5. THRUST BEARING

    DOEpatents

    Heller, P.R.

    1958-09-16

    A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.

  6. Organic Sulfur Gas Production in Sulfidic Caves

    NASA Astrophysics Data System (ADS)

    Stern, L. A.; Engel, A. S.; Bennett, P. C.

    2001-12-01

    Lower Kane Cave, Big Horn Basin, WY, permits access to an environment where anaerobic sulfide-rich groundwater meets the aerobic vadose zone. At this interface microorganisms thrive on diverse metabolic pathways including autotrophic sulfur oxidation, sulfate reduction, and aerobic heterotrophy. Springs introduce groundwater rich in H2S to the cave where it both degasses into the cave atmosphere and is used by chemautotrophic sulfur oxidizing bacteria in the cave spring and stream habitat. The cave atmosphere in the immediate vicinity of the springs has elevated levels of CO2, H2S and methane, mirroring the higher concentration of H2S and methane in the spring water. The high CO2 concentrations are attenuated toward the two main sources of fresh air, the cave entrance and breathing holes at the rear of the cave. Conventional toxic gas monitors permit estimations of H2S concentrations, but they have severe cross sensitivity with other reduced sulfur gases, and thus are inadequate for characterization of sulfur cave gases. However employment of a field-based GC revealed elevated concentrations of carbonyl sulfide in cave atmosphere. Cultures of microorganisms collected from the cave optimized for enriching fermenters and autotrophic and heterophic sulfate reducing bacteria each produced carbonyl sulfide suggesting a biogenic in origin of the COS in addition to H2S. Enrichment cultures also produced methanethiol (methyl mercaptan) and an additional as yet undetermined volatile organic sulfur compound. In culture, the organo-sulfur compounds were less abundant than H2S, whereas in the cave atmosphere the organo-sulfur compounds were the dominant sulfur gases. Thus, these organo-sulfur gases may prove to be important sources of both reduced sulfur and organic carbon to microorganisms living on the cave wall in a subaerial habitat. Moreover groundwater has not yet been recognized as a source of sulfur gases to the atmosphere, but with the abundance of sulfidic

  7. Bilateral Meckel's cave amyloidoma: a case report.

    PubMed

    Gültaşli, N; van den Hauwe, L; Bruneau, M; D'Haene, N; Delpierre, I; Balériaux, D

    2012-05-01

    Primary solitary amyloidoma of Meckel's cave is rare, and a bilateral location is even more rare. To the best of our knowledge, only 12 cases in the literature have described such a primary lesion, including one case of bilateral involvement of Meckel's cave. We report here on the case of a 57-year-old woman presenting with pseudotumor masses involving both Meckel's caves and responsible for trigeminal neuropathy. The final diagnosis of amyloidoma was made on the basis of histological examination of surgical biopsy specimens.

  8. Gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2003-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission.

  9. 14. Detail, crack evidencing structural failure, northeast rear, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Detail, crack evidencing structural failure, northeast rear, view to southwest, 90mm lens. Note failure of sandstone lintel above window. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  10. 15. Detail, cracks evidencing structural failure, northeast rear, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Detail, cracks evidencing structural failure, northeast rear, view to southwest, 90mm lens. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  11. 39 CFR 501.3 - Postage Evidencing System provider qualification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to a provider's Postage Evidencing System or supporting infrastructure, or with the start-up or...) and will cooperate with the Postal Service in every reasonable way to help the Postal Service...

  12. Journal bearing

    DOEpatents

    Menke, John R.; Boeker, Gilbert F.

    1976-05-11

    1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

  13. Southwest Caves Reveal New Forms of Life

    USGS Publications Warehouse

    Wynne, J. Judson; Drost, Charles

    2009-01-01

    Caves in northern Arizona and western New Mexico are being researched and inventoried by scientists with the U.S. Geological Survey and cooperating agencies. Southwestern caves have been little studied, and scientists are now finding that these lightless and nutrient-poor natural systems are home to life forms found nowhere else on Earth. This research has identified unique communities of arthropods (insects, arachnids, and crustaceans) that include 3 new genera, or groups of species, and at least 15 new species - some only known to exist in a single cave. This exciting research is yielding information that will be used by resource managers to better understand and protect fragile and important Southwestern cave ecosystems.

  14. Adult peripheral neuroepithelioma in Meckel's cave.

    PubMed

    Midroni, G; Dhanani, A N; Gray, T; Tucker, W S; Bilbao, J M

    1991-02-01

    A case of peripheral neuroepithelioma arising from the trigeminal nerve in Meckel's cave is presented. The discussion emphasizes the pathological criteria for the diagnosis of a peripheral neuroepithelioma and the current controversy about the classification of this and related tumors.

  15. High resolution CT of Meckel's cave.

    PubMed

    Chui, M; Tucker, W; Hudson, A; Bayer, N

    1985-01-01

    High resolution CT of the parasellar region was carried out in 50 patients studied for suspected pituitary microadenoma, but who showed normal pituitary gland or microadenoma on CT. This control group of patients all showed an ellipsoid low-density area in the posterior parasellar region. Knowledge of the gross anatomy and correlation with metrizamide cisternography suggest that the low density region represents Meckel's cave, rather than just the trigeminal ganglion alone. Though there is considerable variation in the size of Meckel's cave in different patients as well as the two sides of the same patient, the rather constant ellipsoid configuration of the cave in normal subjects will aid in diagnosing small pathological lesions, thereby obviating more invasive cisternography via the transovale or lumbar route. Patients with "idiopathic" tic douloureux do not show a Meckel's cave significantly different from the control group.

  16. Nodal network generator for CAVE3

    NASA Technical Reports Server (NTRS)

    Palmieri, J. V.; Rathjen, K. A.

    1982-01-01

    A new extension of CAVE3 code was developed that automates the creation of a finite difference math model in digital form ready for input to the CAVE3 code. The new software, Nodal Network Generator, is broken into two segments. One segment generates the model geometry using a Tektronix Tablet Digitizer and the other generates the actual finite difference model and allows for graphic verification using Tektronix 4014 Graphic Scope. Use of the Nodal Network Generator is described.

  17. A high-precision chronological model for the decorated Upper Paleolithic cave of Chauvet-Pont d'Arc, Ardèche, France.

    PubMed

    Quiles, Anita; Valladas, Hélène; Bocherens, Hervé; Delqué-Količ, Emmanuelle; Kaltnecker, Evelyne; van der Plicht, Johannes; Delannoy, Jean-Jacques; Feruglio, Valérie; Fritz, Carole; Monney, Julien; Philippe, Michel; Tosello, Gilles; Clottes, Jean; Geneste, Jean-Michel

    2016-04-26

    Radiocarbon dates for the ancient drawings in the Chauvet-Pont d'Arc Cave revealed ages much older than expected. These early ages and nature of this Paleolithic art make this United Nations Educational, Scientific and Cultural Organization (UNESCO) site indisputably unique. A large, multidisciplinary dating program has recently mapped the anthropological evolution associated with the cave. More than 350 dates (by (14)C, U-Th, TL and (36)Cl) were obtained over the last 15 y. They include 259 radiocarbon dates, mainly related to the rock art and human activity in the cave. We present here more than 80 previously unpublished dates. All of the dates were integrated into a high-precision Bayesian model based on archaeological evidence to securely reconstruct the complete history of the Chauvet-Pont d'Arc Cave on an absolute timescale. It shows that there were two distinct periods of human activity in the cave, one from 37 to 33,500 y ago, and the other from 31 to 28,000 y ago. Cave bears also took refuge in the cave until 33,000 y ago.

  18. A high-precision chronological model for the decorated Upper Paleolithic cave of Chauvet-Pont d’Arc, Ardèche, France

    PubMed Central

    Quiles, Anita; Valladas, Hélène; Bocherens, Hervé; Delqué-Količ, Emmanuelle; Kaltnecker, Evelyne; van der Plicht, Johannes; Delannoy, Jean-Jacques; Feruglio, Valérie; Fritz, Carole; Monney, Julien; Philippe, Michel; Tosello, Gilles; Clottes, Jean; Geneste, Jean-Michel

    2016-01-01

    Radiocarbon dates for the ancient drawings in the Chauvet-Pont d’Arc Cave revealed ages much older than expected. These early ages and nature of this Paleolithic art make this United Nations Educational, Scientific and Cultural Organization (UNESCO) site indisputably unique. A large, multidisciplinary dating program has recently mapped the anthropological evolution associated with the cave. More than 350 dates (by 14C, U-Th, TL and 36Cl) were obtained over the last 15 y. They include 259 radiocarbon dates, mainly related to the rock art and human activity in the cave. We present here more than 80 previously unpublished dates. All of the dates were integrated into a high-precision Bayesian model based on archaeological evidence to securely reconstruct the complete history of the Chauvet-Pont d’Arc Cave on an absolute timescale. It shows that there were two distinct periods of human activity in the cave, one from 37 to 33,500 y ago, and the other from 31 to 28,000 y ago. Cave bears also took refuge in the cave until 33,000 y ago. PMID:27071106

  19. On the discovery of a cave lion from the Malyi Anyui River (Chukotka, Russia)

    NASA Astrophysics Data System (ADS)

    Kirillova, I. V.; Tiunov, A. V.; Levchenko, V. A.; Chernova, O. F.; Yudin, V. G.; Bertuch, F.; Shidlovskiy, F. K.

    2015-06-01

    An incomplete postcranial skeleton (67 elements) of a cave lion, a lower jaw and a bundle of fine yellowish hair were found by a local resident in 2008 and 2009 washed out from the perennially frozen Pleistocene sediments in the lower reaches of the Malyi Anyui River (western Chukotka). This is the first skeleton of a cave lion (Panthera spelaea Goldfuss) to be found in Russia. The bone sizes are similar to finds of cave lion bones known from N-E Russia, but larger than East Beringian and smaller than West European ones. The remains have been studied using a variety of methods, including morphology, morphometry, SEM-examination, AMS-dating, and isotopic study, which included examination of over 100 samples of various members of the mammoth faunal assemblage (mammoth, wooly rhinoceros, bison, horse, bear, etc.). The results showed that the northeastern Asian cave lion hunted mainly bison and horses, but not reindeer, unlike its Western Europe counterpart. Bone and claw sheath dating showed an unexpectedly old geochronological age of over 61,000 years (OZQ290, OZQ291), while the hair was dated 28,690 ± 130 (OZQ292), which makes its affinity with the same individual as the skeleton questionable. Further studies to investigate possible unremoved contamination and obtain more reliable date are planned.

  20. GAS BEARING

    DOEpatents

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  1. Grizzly bear

    USGS Publications Warehouse

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  2. Brief communication: beyond the South African cave paradigm--Australopithecus africanus from Plio-Pleistocene paleosol deposits at Taung.

    PubMed

    Hopley, Philip J; Herries, Andy I R; Baker, Stephanie Edwards; Kuhn, Brian F; Menter, Colin G

    2013-06-01

    Following the discovery of the "Taung Child" (Australopithecus africanus) in 1924 in the Buxton-Norlim Limeworks near Taung, the fossil-bearing deposits associated with the Dart and Hrdlička pinnacles have been interpreted as the mined remnants of cave sediments that formed within the Plio-Pleistocene Thabaseek Tufa: either as a younger cave-fill or as contemporaneous carapace caves. When combined with the Plio-Pleistocene dolomitic cave deposits from the "Cradle of Humankind," a rather restricted view emerges that South African early hominins derived from cave deposits, whereas those of east and central Africa are derived from fluvio-lacustrine and paleosol deposits. We undertook a sedimentological and paleomagnetic analysis of the pink-colored deposit (PCS) from which the "Taung Child" is purported to have derived and demonstrate that it is a calcrete, a carbonate-rich pedogenic sediment, which formed on the paleo-land surface. The deposit extends 100 s of meters laterally beyond the Dart and Hrdlička Pinnacles where it is interbedded with the Thabaseek Tufa, indicating multiple episodes of calcrete development and tufa growth. The presence of in situ rhizoconcretions and insect trace fossils (Celliforma sp. and Coprinisphaera sp.) and the distinctive carbonate microfabric confirm that the pink deposit is a pedogenic calcrete, not a calcified cave sediment. Paleomagnetic and stratigraphic evidence indicates that a second, reversed polarity, fossil-bearing deposit (YRSS) is a younger fissure-fill formed within a solutional cavity of the normal polarity tufa and pink calcrete (PCS). These observations have implications for the dating, environment, and taphonomy of the site, and increase the likelihood of future fossil discoveries within the Buxton-Norlim Limeworks.

  3. Evolution of multilevel caves in the Sierra de Atapuerca (Burgos, Spain) and its relation to human occupation

    NASA Astrophysics Data System (ADS)

    Ortega, A. I.; Benito-Calvo, A.; Pérez-González, A.; Martín-Merino, M. A.; Pérez-Martínez, R.; Parés, J. M.; Aramburu, A.; Arsuaga, J. L.; Bermúdez de Castro, J. M.; Carbonell, E.

    2013-08-01

    The evolution of the Torcas cave system (Sierra de Atapuerca) is analysed in order to shed light on the formation of the Atapuerca archaeological sites and human occupation in the area, critical for identifying the paths of the first human dispersal into Europe. The geomorphological analysis of the endokarst system and the regional base levels has revealed a multilevel cave system, with drainage directions from south to north, where old karst springs fed the Pico River. Using morphological and topographic evidence we have correlated the fluvial terraces situated at relative heights of + 84-80 m and + 78-70 m above the Arlanzón River (main course), with the first and second cave levels, respectively, both of Early Pleistocene age. The fluvial levels T4 (+ 60-67 m) and T5 (+ 50-54 m) are linked with the third level (Early-Middle Pleistocene), which contains fluvial deposits probably related to terrace T6 (+ 44-46 m). Progressive fluvial incision allowed humans to gain access to the cave system through several entrances from ~ 1.22 Myr until the end of the Middle Pleistocene, when these cave entrances became filled, forming the most interesting hominid-bearing deposits in Europe.

  4. NASA Aircraft Aids Earth-Mars Cave Detection Study

    NASA Video Gallery

    The most likely location for discovering potential primitive life forms on Mars to be in caves. A recent NASA-funded airborne and ground study designed to aid in detection of caves on the Earth, th...

  5. PATTERNS OF ENDEMISM OF THE EASTERN NORTH AMERICAN CAVE FAUNA

    EPA Science Inventory

    Over 250 species of obligate terrestrial cave-dwelling animals (troglobionts) are known from single caves in the eastern United States. We investigate their geographic distribution, especially in relation to other troglobionts. We relate these patterns to taxonomic group, oppor...

  6. Polar Bear

    USGS Publications Warehouse

    Amstrup, S.D.; ,; Lentfer, J.W.

    1988-01-01

    Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

  7. Solar activity influence on air temperature regimes in caves

    NASA Astrophysics Data System (ADS)

    Stoeva, Penka; Mikhalev, Alexander; Stoev, Alexey

    Cave atmospheres are generally included in the processes that happen in the external atmosphere as circulation of the cave air is connected with the most general circulation of the air in the earth’s atmosphere. Such isolated volumes as the air of caves are also influenced by the variations of solar activity. We discuss cave air temperature response to climate and solar and geomagnetic activity for four show caves in Bulgaria studied for a period of 46 years (1968 - 2013). Everyday noon measurements in Ledenika, Saeva dupka, Snezhanka and Uhlovitsa cave have been used. Temperatures of the air in the zone of constant temperatures (ZCT) are compared with surface temperatures recorded at meteorological stations situated near about the caves - in the towns of Vratsa, Lovech, Peshtera and Smolyan, respectively. For comparison, The Hansen cave, Middle cave and Timpanogos cave from the Timpanogos Cave National Monument, Utah, USA situated nearly at the same latitude have also been examined. Our study shows that the correlation between cave air temperature time series and sunspot number is better than that between the cave air temperature and Apmax indices; that t°ZCT is rather connected with the first peak in geomagnetic activity, which is associated with transient solar activity (CMEs) than with the second one, which is higher and connected with the recurrent high speed streams from coronal holes. Air temperatures of all examined show caves, except the Ledenika cave, which is ice cave show decreasing trends. On the contrary, measurements at the meteorological stations show increasing trends in the surface air temperatures. The trend is decreasing for the Timpanogos cave system, USA. The conclusion is that surface temperature trends depend on the climatic zone, in which the cave is situated, and there is no apparent relation between temperatures inside and outside the caves. We consider possible mechanism of solar cosmic rays influence on the air temperatures in caves

  8. The Tony Grove Karst Region in Northern Utah: From Cave Sediments to Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Smith, H. D.

    2013-12-01

    The Tony Grove lake area is a dolomitic karst region in the Bear River Range of the Middle Rocky Mountain Province (Hintze 1973, Wilson 1976). The 5 km study area (Figure 1) is strewn with boulders and consists of a combination of subsurface dissolution caves underlying the highly-eroded karst surface reminiscent of past glaciation. Traces of the dynamic mountain structure can be seen in faults, fractures, and folds with the largest being the Logan Syncline (Wilson, 1976) formed during the Sevier Orogeny. The Tony Grove area stratigraphy is dominated by the Ordovician (505 MYR) Fish Haven dolomite and Silurian (438 MYR) Laketown dolomite units topped with some Devonian (406 MYR) aged inter-bedded quartzite, shale, and dolostone from the Water Canyon Formation (Morgan 1992, Spangler 2001). The 5 km study area contains over 90 karst features formed through vadose water flow due to the alpine proximity. The development and exhumation of these features have been greatly influenced over time by plate tectonics and water. We investigate cave formation and sediments as an indicator of past water flow and watershed dynamics. Figure 1. Site location of the Tony Grove lake area including an image of the karst terrain and geologic map showing the Logan Peak Syncline. The area is home to about 90 karst features including both do lines and caves. Figure 2. The cave sediments in this image of Thundershower Cave in the Tony Grove lake area show the flow pattern and a step and pool channel morphology with a side channel formed to the right during times of higher flow.

  9. The Tony Grove Karst Region in Northern Utah: From Cave Sediments to Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Smith, H. D.

    2012-12-01

    The Tony Grove lake area is a dolomitic karst region in the Bear River Range of the Middle Rocky Mountain Province (Hintze, 1973; Wilson, 1976). Figure 1. The 5 km study area is strewn with boulders and consists of a combination of subsurface dissolution caves underlying the highly-eroded karst surface remnancent of past glaciation. Traces of the dynamic mountain structure can be seen in faults, fractures, and folds with the largest being the Logan Syncline (Wilson, 1976) formed during the Sevier Orogeny. The Tony Grove area stratigraphy is dominated by the Ordovician (505 MYR) Fish Haven dolomite and Silurian (438 MYR) Laketown dolomite units topped with some Devonian (406 MYR) aged inter-bedded quartzite, shale, and dolostone from the Water Canyon Formation (Morgan 1992, Spangler 2001). The 5 km study area contains over 90 karst features formed through vadose water flow due to the alpine proximity. The development and exhumation of these features have been greatly influenced over time by plate tectonics and water. We investigate cave formation and sediments as an indicator of past water flow and watershed dynamics (Figure 2). Figure 1. Site location of the Tony Grove Lake Area including an image of the karst terrain and geologic map showing the Logan Peak Syncline. The area is home to about 90 karst features inculding both dolines and caves. Figure 2. The cave sediments in this image of Thundershower Cave in the Tony Grove Lake Area show the flow pattern and a step and pool channel morphology with a side channel formed to the right during times of higher flow.

  10. The first record of "spelaeoid" bears in Arctic Siberia

    NASA Astrophysics Data System (ADS)

    Sher, Andrei V.; Weinstock, Jacobo; Baryshnikov, Gennady F.; Davydov, Sergey P.; Boeskorov, Gennady G.; Zazhigin, Vladimir S.; Nikolskiy, Pavel A.

    2011-08-01

    For a long time, "spelaeoid" (cave-bear-like) bears, Ursus ( Spelearctos) spp., were believed to be almost purely European animals. Their geographic range has recently been extended to the east, in southern Siberia, Transbaikalia, Kirghizia, Mongolia and Korea. Two unexpected new findings, presented here in detail, significantly change existing views on the distribution of cave bears; both were found in North-Eastern Siberia, far beyond the Arctic Circle, more than 1500 km to the north-east of the previously accepted range. One of the fossils is a mandible, found near the town of Cherskiy at 68.73°N, 161.38°E. The analysis of local geology and accompanying mammal fossils suggests that it comes from the Olyorian Fauna (Early to early Middle Pleistocene). Morphologically, the Cherskiy mandible is closest to Ursus savini, a small middle Pleistocene cave bear from the British Cromer Forest-bed Formation, but differs in having a slightly more advanced dentition, and thus it is described as a new subspecies Ursus savini nordostensis. Another newly recognized fossil of the "spelaeoid" bear is an astragalus found at the Oskhordokh site at 67.54°N, 135.67°E, on a large gravel bar on the right bank of the Adycha River. This specimen is attributed to Ursus cf . deningeri. The paper also presents an interesting example of the interaction between classical and "molecular" palaeontology. The new finds significantly change existing ideas on the ecology and evolution of cave bears, some of the most remarkable members of the extinct Pleistocene megafauna.

  11. 39 CFR 501.7 - Postage Evidencing System requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... on the Postal Service Web site at http://www.usps.com/postagesolutions/programdoc.html or...

  12. 39 CFR 501.2 - Postage Evidencing System provider authorization.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... applicant's integrity and financial responsibility, commitment to the security of the Postage Evidencing..., security, and servicing functions and the need to maintain sufficient financial reserves to guarantee... Suite 4200, Washington, DC 20260-4200. Information updates may be found on the Postal Service Web...

  13. 39 CFR 501.7 - Postage Evidencing System requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... on the Postal Service Web site at http://www.usps.com/postagesolutions/programdoc.html or...

  14. 39 CFR 501.2 - Postage Evidencing System provider authorization.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... applicant's integrity and financial responsibility, commitment to the security of the Postage Evidencing..., security, and servicing functions and the need to maintain sufficient financial reserves to guarantee... Suite 4200, Washington, DC 20260-4200. Information updates may be found on the Postal Service Web...

  15. 39 CFR 501.2 - Postage Evidencing System provider authorization.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... applicant's integrity and financial responsibility, commitment to the security of the Postage Evidencing..., security, and servicing functions and the need to maintain sufficient financial reserves to guarantee... Suite 4200, Washington, DC 20260-4200. Information updates may be found on the Postal Service Web...

  16. 39 CFR 501.7 - Postage Evidencing System requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... on the Postal Service Web site at http://www.usps.com/postagesolutions/programdoc.html or...

  17. 39 CFR 501.7 - Postage Evidencing System requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... 604.4.0 and the Performance Criteria for Information-Based Indicia and Security Architecture for...

  18. 7 CFR 1260.313 - Document evidencing payment of assessments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Document evidencing payment of assessments. 1260.313 Section 1260.313 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF...

  19. 7 CFR 1260.313 - Document evidencing payment of assessments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to give the producer from whom the collecting person collected an assessment written evidence of payment of the Beef Promotion and Research Assessments. Such written evidence serving as a receipt shall... 7 Agriculture 10 2010-01-01 2010-01-01 false Document evidencing payment of assessments....

  20. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  1. Parallel speciation in Astyanax cave fish (Teleostei) in Northern Mexico.

    PubMed

    Strecker, Ulrike; Hausdorf, Bernhard; Wilkens, Horst

    2012-01-01

    We investigated differentiation processes in the Neotropical fish Astyanax that represents a model system for examining adaptation to caves, including regressive evolution. In particular, we analyzed microsatellite and mitochondrial data of seven cave and seven surface populations from Mexico to test whether the evolution of the cave fish represents a case of parallel evolution. Our data revealed that Astyanax invaded northern Mexico across the Trans-Mexican Volcanic Belt at least three times and that populations of all three invasions adapted to subterranean habitats. Significant differentiation was found between the cave and surface populations. We did not observe gene flow between the strongly eye and pigment reduced old cave populations (Sabinos, Tinaja, Pachon) and the surface fish, even when syntopically occurring like in Yerbaniz cave. Little gene flow, if any, was found between cave populations, which are variable in eye and pigmentation (Micos, Chica, Caballo Moro caves), and surface fish. This suggests that the variability is due to their more recent origin rather than to hybridization. Finally, admixture of the young Chica cave fish population with nuclear markers from older cave fish demonstrates that gene flow between populations that independently colonized caves occurs. Thus, all criteria of parallel speciation are fulfilled. Moreover, the microsatellite data provide evidence that two co-occurring groups with small sunken eyes and externally visible eyes, respectively, differentiated within the partly lightened Caballo Moro karst window cave and might represent an example for incipient sympatric speciation.

  2. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  3. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  4. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  5. 75 FR 4417 - Wind Cave National Park, Custer County, SD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... Wind Cave National Park, Custer County, SD AGENCY: National Park Service. ACTION: Notice of... Statement, Wind Cave National Park, Custer County, South Dakota. SUMMARY: Pursuant to Section 102(2)(C) of... Environmental Impact Statement (Plan), Wind Cave National Park, Custer County, South Dakota. On December 3,...

  6. Metabolically active Crenarchaeota in Altamira Cave.

    PubMed

    Gonzalez, Juan M; Portillo, M Carmen; Saiz-Jimenez, Cesareo

    2006-01-01

    Altamira Cave contains valuable paleolithic paintings dating back to 15,000 years. The conservation of these unique paintings is attracting increasing interest, and so, understanding microbial proliferation in Altamira Cave represents a prioritary objective. Here, we show for the first time that members of the Crenarchaeota were metabolically active components of developing microbial communities. RNA was extracted directly from the studied environment, and a number of 16S rRNA gene sequences belonging to the low-temperature Crenarchaeota were detected. Although low-temperature Crenarchaeota detected in a variety of ecosystems by using molecular techniques remain uncultured, this RNA-based study confirms an active participation of the Crenarchaeota in cave biogeochemical cycles.

  7. Isotopic evidence for Last Glacial climatic impacts on Neanderthal gazelle hunting territories at Amud Cave, Israel.

    PubMed

    Hartman, Gideon; Hovers, Erella; Hublin, Jean-Jacques; Richards, Michael

    2015-07-01

    The Middle Paleolithic site of Amud Cave, Israel, was occupied by Neanderthals at two different time periods, evidenced by two chronologically and stratigraphically distinct depositional sub-units (B4 and B2/B1) during MIS 4 and MIS 3, respectively. The composition of both hunted large fauna and naturally-deposited micromammalian taxa is stable at the site over time, despite a ∼ 10 ky gap between the two occupation phases. However, while gazelle is the most ubiquitous hunted species throughout the occupation, isotopic analysis showed that there is a marked change in Neanderthal hunting ranges between the early (B4) and late (B2/B1) phases. Hunting ranges were reconstructed by comparing oxygen, carbon, and strontium isotopes from gazelle tooth enamel with modern isotope data from the Amud Cave region. This region is characterized by extensive topographic, lithological, and pedological heterogeneity. During the early occupation phase negative oxygen isotope values, low radiogenic (87)Sr/(86)Sr ratios, and low Sr concentrations reveal restricted gazelle hunting in the high elevations west of Amud Cave. In the late occupation phase, hunting ranges became more diverse, but concentrate at low elevations closer to the site. Climatic proxies indicate that conditions were drier in the early occupation phase, which may have pushed gazelle populations into higher, more productive foraging areas. This study showed that Neanderthals adjusted their hunting territories considerably in relation to varying environmental conditions over the course of occupation in Amud Cave. It highlights the utility of multiple isotope analysis in enhancing the resolution of behavioral interpretations based on faunal remains and in reconstructing past hunting behaviors of Paleolithic hominins.

  8. Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    AVCON, Inc. produces advanced magnetic bearing systems for industrial use, offering a unique technological approach based on contract work done at Marshall Space Flight Center and Lewis Research Center. Designed for the turbopump of the Space Shuttle main engine, they are now used in applications such as electric power generation, petroleum refining, machine tool operation and natural gas pipelines. Magnetic bearings support moving machinery without physical contact; AVCON's homopolar approach is a hybrid of permanent and electromagnets which are one-third the weight, smaller and more power- efficient than previous magnetic bearings.

  9. 78 FR 8407 - Authorization To Manufacture and Distribute Postage Evidencing Systems; Discontinued Indicia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... 501 Authorization To Manufacture and Distribute Postage Evidencing Systems; Discontinued Indicia... Service introduced the Information Based Indicia Program (IBIP). Under IBIP, postage evidencing systems... concerning the manufacture and distribution of postage evidencing systems to clarify that effective January...

  10. 77 FR 41336 - Authorization to Manufacture and Distribute Postage Evidencing Systems; Discontinued Indicia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... 501 Authorization to Manufacture and Distribute Postage Evidencing Systems; Discontinued Indicia... information. Effective January 1, 2016, all postage evidencing systems (postage meters and PC Postage products... rules concerning the manufacture and distribution of postage evidencing systems to clarify...

  11. Meckel's cave meningiomas with subarachnoid hemorrhage.

    PubMed

    Rosenberg, G A; Herz, D A; Leeds, N; Strully, K

    1975-06-01

    Two patients with Meckel's Cave meningiomas were initially hospitalized as a result of subarachnoid hemorrhage. Four-vessel angiography was necessary to exclude other causes of bleeding while demonstrating these lesions. Apoplectic presentation in both cases led to early diagnosis and successful surgical therapy. A review of the literature reveals subarachnoid hemorrhage to be a rarity in association with meningiomas. The two patients currently reported are believed to be the only examples on record of hemorrhagic meningiomas arising from the region of Meckel's Cave.

  12. Foil bearings

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1993-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  13. Foil bearings

    NASA Astrophysics Data System (ADS)

    Elrod, David A.

    1993-11-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  14. Preliminary investigation of a late Wisconsinan fauna from K1 cave, Queen Charlotte Islands (Haida Gwaii), Canada

    NASA Astrophysics Data System (ADS)

    Ramsey, Carolyn L.; Griffiths, Paul A.; Fedje, Daryl W.; Wigen, Rebecca J.; Mackie, Quentin

    2004-07-01

    Recent investigations of a limestone solution cave on the Queen Charlotte Islands (Haida Gwaii) have yielded skeletal remains of fauna including late Pleistocene and early Holocene bears, one specimen of which dates to ca. 14,400 14C yr B.P. This new fossil evidence sheds light on early postglacial environmental conditions in this archipelago, with implications for the timing of early human migration into the Americas.

  15. Regime switch in karstic caves atmosphere; possible consequence on annual speleothem growth.

    NASA Astrophysics Data System (ADS)

    Bourges, F.; Genthon, P.; Mangin, A.; D'Hulst, D.

    2005-12-01

    Speleothem are usually considered as records of past climate, and are supposed to present annual growth rings. Yet, they grow inside caves that benefit from very stable environment. However, Bourges et al. 2001, have shown that the atmosphere of Aven d'Orgnac (South East France), was characterized by drop of CO2 concentration and 222Rn activity at the end of autumn and presented each year the succession of a winter and a summer regime. Temperature data are now used to constrain the climate of this cave system. Our data consist in 5 years monitoring with 0.01°C accuracy, three short thermal profiling campaigns, and sparser data gathered in different French painted caves. Near the opening of Aven d'Orgnac, the Salle de Jolys room records each year at the end of autumn the onset of the winter regime that is shown to be triggered by the inverse density stratification induced by the decrease of the outside night temperature. Comparison of summer and winter vertical temperature profiles point to a thermoconvective destabilization of this room atmosphere, involving the downward flow of cold outside bearing air near the cave floor during winter nights. The winter regime propagates then stepwise inside the Aven d'Orgnac cave system. In Salle Plane, which is situated more than one kilometer away from the entrance, the winter regime has never been observed. Our thermal profiling experiment shows there low amplitude (0.03°C) temperature changes, with major daily and half daily components, that are strongly correlated with the pressure first time derivative. Comparison with temperature records from other rooms of the Aven d'Orgnac cave system and with other caves monitored by our team suggest that a strong correlation between temperature changes and the pressure first time derivative could be considered as a clue to the confined character of a given cave room. We propose therefore that the Aven d'Orgnac cave system could be divided in two parts : the open system, where the

  16. Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia

    USGS Publications Warehouse

    Schreiber, Madeline E.; Schwartz, Benjamin F.; Orndorff, William; Doctor, Daniel H.; Eagle, Sarah D.; Gerst, Jonathan D.

    2015-01-01

    Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave, Virginia, to evaluate the quantity and quality of recharge to the karst system. To achieve this goal, the cave has been instrumented for continuous (10-min interval) measurement of the (1) temperature and rate of precipitation; (2) temperature, specific conductance, and rate of epikarst dripwater; (3) temperature of the cave air; and (4) temperature, conductivity, and discharge of the cave stream. Instrumentation has also been installed to collect both composite and grab samples of precipitation, soil water, the cave stream, and dripwater for geochemical analysis. This chapter provides detailed information about the instrumentation, data processing, and data management; shows examples of collected datasets; and discusses recommendations for other researchers interested in hydrologic and geochemical monitoring of cave systems. Results from the research, briefly described here and discussed in more detail in other publications, document a strong seasonality of the start of the recharge season, the extent of the recharge season, and the geochemistry of recharge.

  17. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    PubMed

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  18. Is Radon Emission in Caves Causing Deletions in Satellite DNA Sequences of Cave-Dwelling Crickets?

    PubMed Central

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration. PMID:25822625

  19. Helium Isotopes and Noble Gas Abundances of Cave Dripping Water in Three Caves in East Asia

    NASA Astrophysics Data System (ADS)

    Chen, A. T.; Shen, C. C.; Tan, M.; Li, T.; Uemura, R.; Asami, R.

    2015-12-01

    Paleo-temperature recorded in nature archives is a critical parameter to understand climate change in the past. With advantages of unique inert chemical characteristics and sensitive solubilities with temperature, dissolved noble gases in speleothem inclusion water were recently proposed to retrieve terrestrial temperature history. In order to accurately apply this newly-developed speleothem noble gas temperature (NGT) as a reliable proxy, a fundamental issue about behaviors of noble gases in the karst should be first clarified. In this study, we measured noble gas contents in air and dripping water to evaluate any ratio deviation between noble gases. Cave dripping water samples was collected from three selected caves, Shihua Cave in northern China, Furong Cave in southwestern, and Gyukusen Cave in an island located in the western Pacific. For these caves are characterized by a thorough mixing and long-term storage of waters in a karst aquifer by the absence of seasonal oxygen isotope shifts. Ratios of dripping water noble gases are statistically insignificant from air data. Helium isotopic ratios in the dripping water samples match air value. The results indicate that elemental and isotopic signatures of noble gases from air can be frankly preserved in the epikarst and support the fidelity of NGT techniques.

  20. Community Action Volunteers in Education (CAVE).

    ERIC Educational Resources Information Center

    Summerville, Janet R.

    The Community Action Volunteers in Education (CAVE), which is described in this report, is a co-curricular learning, non-profit agency offering over 16 programs to children, the elderly, special populations, and low-income residents in the Chico, California, area and in three state institutions in the Napa and Sonoma Valleys. Based at California…

  1. Meckel's cave tuberculoma with unusual infratemporal extension.

    PubMed

    Kesavadas, Chandrasekharan; Somasundaram, S; Rao, Ravi M; Radhakrishnan, V V

    2007-07-01

    The authors describe a rare case of intracranial tuberculoma of the Meckel's cave and cavernous sinus with extension into the infratemporal fossa causing widening of the foramen ovale and adjacent bone destruction. The rarity of the lesion and the unusual extension of the lesion are presented with a brief review of literature.

  2. Xanthoma in Meckel's cave. A case report.

    PubMed

    Kimura, H; Oka, K; Nakayama, Y; Tomonaga, M

    1991-04-01

    A case of xanthoma located within Meckel's cave and the semilunar ganglion is described in a patient with a trigeminal nerve deficit. This is the first case of xanthoma in such a location. The distinctive morphological appearance is illustrated and the possible histogenesis is discussed.

  3. Magnetostratigraphy of cave sediments, Wyandotte Ridge, Crawford County, southern Indiana

    SciTech Connect

    Pease, P.P.; Gomez, B. . Dept. of Geography and Geology); Schmidt, V.A. . Dept. of Geology and Planetary Science)

    1992-01-01

    The field polarities of 42 sediment samples obtained from 21 sites in Wyandotte Cave, and five smaller satellite caves in Wyandotte Ridge, southern Indiana, have been determined and correlated with magnetostratigraphic data from Mammoth Cave, Kentucky. In Wyandotte Cave sediment samples obtained between 137 m and 162 m in elevation possessed a normal field polarity, while samples obtained between 168 m and 171 m exhibited a field reversal. The reversal was interpreted to represent the most recent polarity change, dating the sediment fill and the end of the active period of the upper level of Wyandotte Cave at ca 0.788 Ma. There is a temporal correlation between the active period of the upper level in Wyandotte Cave and the C-level in Mammoth Cave, which lies at a similar elevation. Such a correlation is most likely a consequence of the contemporaneous abandonment of passages in the two cave systems during the early Pleistocene reconstruction of the Ohio River system, which acts as the base level control in both caves. Samples from two caves near the top of Wyandotte Ridge, located between elevations of 236 m and 241 m, exhibited a normal polarity. These caves are located at a higher elevation than any of the sample sites in Mammoth Cave and their location suggests that the fill predates sediments from that system. It appears most likely that the fill in these caves is a minimum of ca 2.48 Ma. old and correlates with the residuum of the upper Mitchell Plain surface, not with the fill in the upper (A- or B-levels) in Mammoth Cave.

  4. The Crystals Cave in a test tube

    NASA Astrophysics Data System (ADS)

    Puig, C.; Romero, M. L.

    2012-04-01

    It's quite easy to understand formation of crystals in Nature by evaporation of the solutions that contain minerals, but many times we have realised that our pupils hardly understand that precipitation is a process mostly caused by changing parameters in a solution, like pH, temperature, etc. and not necessarily depending on evaporation. We propose a hands-on activity using the context of the Cave of the Crystals in Naica's mine, Mexico. The Crystals Cave is a wonderful place where giant crystals of selenite (gypsum) have grown feeding from a supersaturated anhydrite solution1. Miners discovered the cave filled with hot water, and drained it to explore the gallery. The cave is now a giant laboratory where scientists are looking for the keys to understand geological processes. Teaching sequence (for students 15 years old) is as follows: DISCOVERING A MARVELLOUS PLACE: We showed our pupils several images and a short video of the Cave of the Crystals and ask them about the process that may have caused the phenomenon. Whole-class discussion. PRESENTING A CHALLENGE TO OUR STUDENTS: "COULD WE CREATE A CRYSTALS CAVE IN A TEST TUBE?" EXPERIMENTING TO IMITATE NATURE: Students tried to grow crystals simulating the same conditions as those in Naica's mine. We have chosen KNO3, a salt more soluble than gypsum. We added 85 g of salt to 200 ml of water (solubility of KNO3 at 25°C is 36 g per 100 gr of water) and heated it until it is dissolved. Afterwards, we poured the solution into some test tubes and other recipients and let them cool at room temperature. And they got a beautiful crystals cave!! THINKING A LITTLE MORE: we asked pupils some questions to make them think about the process and to predict what would happen in different situations. For example: a) What would happen with crystals if we heated the tubes again? or b) What would happen if we took the remaining solution from the tubes and keep it in the fridge? PROVING A NEW HYPOTHESIS: Pupils collected the remaining

  5. Shells and ochre in Middle Paleolithic Qafzeh Cave, Israel: indications for modern behavior.

    PubMed

    Bar-Yosef Mayer, Daniella E; Vandermeersch, Bernard; Bar-Yosef, Ofer

    2009-03-01

    Qafzeh Cave, the burial grounds of several anatomically modern humans, producers of Mousterian industry, yielded archaeological evidence reflecting their modern behavior. Dated to 92ka BP, the lower layers at the site contained a series of hearths, several human graves, flint artifacts, animal bones, a collection of sea shells, lumps of red ochre, and an incised cortical flake. The marine shells were recovered from layers earlier than most of the graves except for one burial. The shells were collected and brought from the Mediterranean Sea shore some 35km away, and are complete Glycymeris bivalves, naturally perforated. Several valves bear traces of having been strung, and a few had ochre stains on them.

  6. Large mammal taphonomy of the Middle Pleistocene hominid occupation at Treugol'naya Cave (Northern Caucasus)

    NASA Astrophysics Data System (ADS)

    Hoffecker, John F.; Baryshnikov, G. F.; Doronichev, V. B.

    2003-03-01

    A taphonomic study was conducted of large mammal remains from the Middle Pleistocene site of Treugol'naya Cave. The site is located at an elevation of 1500 m above sea level near the town of Pregradnaya in the northwestern Caucasus region of Russia, and was excavated by Doronichev (Doronichev, V.B., 2000. Lower paleolithic occupation of the northern Caucasus. ERAUL 92, 67-77.) between 1986 and 2000. Large mammal remains were identified by Baryshnikov (Baryshnikov, G.F., 1993. Krupnye mlekopitayushchie ashelskoi stoyanki v peshchere Treugol'naya na Severnom Kavkaze. Trudy Zoologicheskogo instituta RAN 249, 3-47), and reflect predominance of red deer ( Cervus elaphus), bison ( Bison schoetensacki), and cave bear ( Spelaearctos deningeri). Less common taxa include goat ( Capra sp.), wolf ( Canis mosbachensis), rhinoceros ( Stephanorhinus hundsheimensis) and horse ( Equus altidens). Data were collected on weathering, breakage, surficial damage, skeletal-part frequencies, and age and season of death from the these remains, which are stored at the Zoological Institute, Russian Academy of Sciences in St. Petersburg. Analysis of the data revealed little evidence for accumulation of the large mammal remains by the hominid occupants of the cave. The carnivore remains probably represent natural mortality, while some of the ungulate remains were apparently accumulated by stream action. Most of the remaining ungulate remains were probably collected by carnivores.

  7. 39 CFR 501.9 - Demonstration or test Postage Evidencing Systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.9 Demonstration or test Postage Evidencing Systems. (a) A demonstration or test postage evidencing system is any system that produces an image that... 39 Postal Service 1 2010-07-01 2010-07-01 false Demonstration or test Postage Evidencing...

  8. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TO MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.11 Reporting Postage Evidencing System... protection features, capabilities, or failings of any Postage Evidencing System sold, leased, or distributed... Postage Evidencing Systems that the provider distributes of which it knows or should know and the...

  9. Exploring caves: teaching packet for grades K-3

    USGS Publications Warehouse

    ,

    1998-01-01

    "Exploring Caves" is an interdisciplinary set of materials on caves for grades K-3. Caves entail at least five scientific disciplines: earth science, hydrology, mapping, biology, and anthropology. Each of these disciplines involves a unique content area as well as the development of particular intellectual skills. This unit aims at helping teachers to sort and organize the most important ideas in this rich scientific area. Detailed lesson plans serve as ways to pass these ideas on to very young students. Most American caves are big holes that form in limestone rock. The holes begin as cracks in limestone. The cracks get bigger and bigger. They grow into underground streams, rivers, and even lakes. When water drains away, the waterways turn into open cave tunnels, passages, and caverns. It takes 10,000 to 100,000 years to form a cave big enough for people to move around inside. Water drips constantly in caves. The drips dissolve limestone minerals in one part of the cave. As water dries out, the minerals build up in other places. In this way, beautiful cave rock formations and crystals grow over thousands of years. These rock formations change dark limestone caves into hidden fantasy lands.

  10. Pre-excavation studies of prehistoric cave sites by magnetic prospecting

    NASA Astrophysics Data System (ADS)

    Itkis., Sonia; Matskevich, Zinovii; Meshveliani, Tengiz

    2014-05-01

    lithic material to Mesolithic and Early Neolithic periods. The upper layer is ca 50 cm thick, consists of fine grey silt with few pebbles and includes numerous bones and lithic implements. In this layer two circular dense concentrations of charcoal, possibly fireplaces were discovered. Conclusions 1. The results of magnetic survey obtained in prehistoric cave sites in Israel and Georgia show the high efficiency of the magnetic method for revealing and detailed characterization of caves. 2. The presence of organic materials, e.g. bones, charcoals and ceramics in caves enhances magnetic contrast between non-magnetic bedrock and the cave's fill, increasing the potential of the magnetic method. 3. Revealing enhanced magnetization of soil within studied caves allowed us to develop an approach to reliable interpretation of magnetic data in studied areas References Bar-Oz, G., Belfer-Cohen, A, Meshvelliani, T., Jakeli, N., Matskevich, Z. and Bar-Yosef, O. 2009. Bear in mind: bear hunting in the Mesolithic of the Southern Caucasus, the case of Kotias Klde rockshelter, western Georgia. Archaeology, Ethnology and Anthropology of Eurasia 37 (1): 15-24. Dalan, R. A. and Banerjee, S. K. 1998. Solving archaeological problems using techniques of soil magnetism. Geoarchaeology: An International Journal, Vol. 13, No.1, pp.1-36. Fassbinder, J.W. E. , Stanijek, H. and Vali, H. 1990. Occurence of magnetic bacteria in soil. Nature 343, 161-163. Itkis, S. 2003. Magnetic Susceptibility Measurements of Soil: A Diagnostic Tool for Location of Human Activity Areas (Ch. 14) In: Khalaily, H. and Marder, O. (editors). The Neolithic Site of Abu Ghosh: The 1995 Excavations. IAA Reports, No.19. Jerusalem. p. 129-131. Itkis, S. 2011..Magnetic survey at Ramat Bet Shemesh. In: Dagan Y. (editor). The Ramat Bet Shemesh Regional Project: Landscapes of Settlement from the Paleolithic to the Ottoman Period, IAA Reports, No. 47, Israel Antiquites Authority, Jerusalem 2011, pp. 95-104. Itkis S.E and Eppelbaum L

  11. Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions

    PubMed Central

    Riquelme, Cristina; Marshall Hathaway, Jennifer J.; Enes Dapkevicius, Maria de L. N.; Miller, Ana Z.; Kooser, Ara; Northup, Diana E.; Jurado, Valme; Fernandez, Octavio; Saiz-Jimenez, Cesareo; Cheeptham, Naowarat

    2015-01-01

    Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in

  12. The magnesium isotope record of cave carbonate archives

    NASA Astrophysics Data System (ADS)

    Riechelmann, S.; Buhl, D.; Schröder-Ritzrau, A.; Riechelmann, D. F. C.; Richter, D. K.; Vonhof, H. B.; Wassenburg, J. A.; Geske, A.; Spötl, C.; Immenhauser, A.

    2012-11-01

    δ26Mg values of the German speleothems are shifted to higher values due to sampling in detrital layers (Mg-bearing clay minerals) of the speleothems. The data and their interpretation shown here highlight the potential but also the limitations of the magnesium isotope proxy applied in continental climate research. An obvious potential lies in its sensitivity for even subtle changes in soil-zone parameters, a hitherto rather poorly understood but extremely important component in cave archive research. Limitations are most obvious in the low resolution and high sample amount needed for analysis. Future research should focus on experimental and conceptual aspects including quantitative and well-calibrated leaching and precipitation experiments.

  13. The magnesium isotope record of cave carbonate archives

    NASA Astrophysics Data System (ADS)

    Riechelmann, S.; Buhl, D.; Schröder-Ritzrau, A.; Riechelmann, D. F. C.; Richter, D. K.; Vonhof, H. B.; Wassenburg, J. A.; Geske, A.; Spötl, C.; Immenhauser, A.

    2012-05-01

    German speleothems are shifted to higher values due to sampling in detrital layers (Mg-bearing clay minerals) of the speleothems. The data and their interpretation shown here highlight the potential but also the limitations of the magnesium isotope proxy applied in continental climate research. An obvious potential lies in its sensitivity for even subtle changes in soil-zone parameters, a hitherto rather poorly understood but extremely important component in cave archive research. Limitations are most obvious in the low resolution and high sample amount needed for analysis. Future research should focus on experimental and conceptual aspects including quantitative and well calibrated leaching and precipitation experiments.

  14. Temperature as tracer of the hydraulic dynamic of an anchialine cave (coastal submerged cave) of Krka Estuary (Croatia)

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David; Cukrov, Neven; Krklec, Kristina

    2016-04-01

    A series of temperature, conductivity and water level loggers were used to characterize the hydraulic dynamic of a submerged cave (anchialine cave) in Krka Estuary. Litno Cave is a sub-horizontal gallery, less than 5 m in diameter and one meter below sea level. Apart from some sections that contain occasional air pockets under the ceiling, the cave is completely flooded. Outflow discharge through the cave is continuous during the year (>30 l/s). During several months vertical temperature profiles were measured in three locations inside the cave at 20, 60 and 100 m from the cave entrance, whereas another vertical profile was set in the estuary in front of the cave. Thermometers from the estuary measured thermal gradients to characterize position and evolution of the thermocline up to a depth of 3.5 m. Tides measured in the estuary are synchronous to those recorded in the cave and their amplitudes (20 to 40 cm in the estuary) are the same or smaller depending on cave outflow discharge. Records of cave water temperature show a non-linear response to tides due to the vertical displacement of the thermocline. During neap tides the thermocline was located in the aquifer below the cave, whereas during spring tides only thermometers in the top meter of the cave were not affected by the thermocline vertical displacement. After the first significant rains of the hydrological year, the freshwater contribution increased the cave outflow discharge by one order of magnitude. Thus, conductivity decreased in response to rains from 16000 ±1000 μS/cm to <700 μS/cm at the bottom of the cave. Under these conditions variability of cave water temperature was less than 0.1 °C, although a 0.4 °C long-term variability was recorded. These data shows that the discharge of freshwater to the estuary determines the dynamic of this submerged cave, limiting the influence of estuarine water intrusion in the coastal aquifer and the impact of tides. This research shows that temperature is a

  15. Contribution of stable isotopes (C,N,S) in collagen of late Pleistocene large mammal trophic ecology and landscape use: a case study in Goyet and Scladina cave (30-40,000 years BP)

    NASA Astrophysics Data System (ADS)

    Bocherens, Hervé; Germonpré, Mietje

    2010-05-01

    Two Belgian caves yielded very rich large mammal associations dating around 30 to 40,000 years ago: Goyet and Scladina cave (layer 1A). These sites are only 5 km apart but the cave entrances open on different valleys, in a quite diverse landscape ranging between open, unprotected uplands, steep cliffs and sheltered sun-exposed gorges, with the larger Meuse valley nearby. This mosaic scenery permitted during the Last Glacial a rich diversity of fossil flora and fauna. The faunal association includes a large diversity of taxa including Aurochs Bos primigenius, steppe bison Bison priscus, reindeer Rangifer tarandus, giant deer Megaloceros giganteus, horse Equus ferus, woolly rhinoceros Coelodonta antiquitatis, woolly mammoth Mammuthus primigenius, cave bear Ursus spelaeus, brown bear Ursus arctos, wolf Canis lupus, cave lion Panthera leo spelaea, and cave hyaena Crocuta crocuta spelaea. All the 90 studied bones and teeth yielded collagen with excellent collagen preservation, allowing reliable investigations of carbon, nitrogen and sulfur isotopic biogeochemistry. The combination of three different isotopic tracers allows to deciphering the effects of food selection and landscape use by different herbivorous and carnivorous taxa. This is the first study to include sulfur isotopic signatures in the study of late Quaternary large mammal palaeobiology. This new tracer yields evidence on mobility and differences in pasture areas, as different geological bedrock may exhibit various sulfur isotopic signatures that will pass on the herbivores and further on their predators. Using this feature in addition to the trophic information provided by carbon and nitrogen isotopic signatures, it appears that for some species present in both sites, such as horse and woolly rhinoceros, the individuals found in each site probably did not use the same pasture areas. This seems to also the case for the overwhelmingly vegetarian cave bears. In addition, individuals from the same species

  16. A biosignature suite from cave pool precipitates, Cottonwood Cave, New Mexico.

    PubMed

    Melim, L A; Liescheidt, R; Northup, D E; Spilde, M N; Boston, P J; Queen, J M

    2009-11-01

    Calcite cave pool precipitates often display a variety of potential biosignatures from the macroscopic to the submicroscopic. A fossil cave pool in Cottonwood Cave, New Mexico, exhibits older stalactites and stalagmites that are completely coated in brown, laminated calcitic crust that extends down as pool fingers and u-loops. The pool fingers and u-loops are mainly micrite to clotted micrite, some recrystallized to microspar, with some isopachous spar layers. Micrite, particularly clotted micrite, is usually interpreted by carbonate workers as microbial in origin. Scanning electron microscopy examination of etched pool fingers, u-loops, and the brown crust revealed abundant calcified microbial filaments and biofilm. Energy dispersive X-ray analysis showed that these features have excess carbon, above that found in pure calcite. Independent carbon analysis indicated that these same samples contain up to 0.2% organic carbon. Since pool fingers hang down but form underwater, we hypothesize they are biogenic with hanging microbial filaments or biofilm acting as nuclei for calcite precipitation. Because of the abundance of micrite and fossil filaments, we further hypothesize that these pendant features formed during a period of plentiful nutrients and active hydrological activity when the pool was literally dripping with microbial slime. Although each of these lines of evidence could be interpreted in other ways, their combined weight strongly suggests the cave pool precipitates in Cottonwood Cave are biogenic. These investigations can be used to help inform extraterrestrial life-detection studies.

  17. Molecular phylogeny of the extinct cave lion Panthera leo spelaea.

    PubMed

    Burger, Joachim; Rosendahl, Wilfried; Loreille, Odile; Hemmer, Helmut; Eriksson, Torsten; Götherström, Anders; Hiller, Jennifer; Collins, Matthew J; Wess, Timothy; Alt, Kurt W

    2004-03-01

    To reconstruct the phylogenetic position of the extinct cave lion (Panthera leo spelaea), we sequenced 1 kb of the mitochondrial cytochrome b gene from two Pleistocene cave lion DNA samples (47 and 32 ky B.P.). Phylogenetic analysis shows that the ancient sequences form a clade that is most closely related to the extant lions from Africa and Asia; at the same time, cave lions appear to be highly distinct from their living relatives. Our data show that these cave lion sequences represent lineages that were isolated from lions in Africa and Asia since their dispersal over Europe about 600 ky B.P., as they are not found among our sample of extant populations. The cave lion lineages presented here went extinct without mitochondrial descendants on other continents. The high sequence divergence in the cytochrome b gene between cave and modern lions is notable.

  18. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms or animals, or... humans, biota, or development of cave resources. (5) Recreational. The cave provides or could...

  19. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... recreational purposes, the opportunity to nominate caves. The authorized officer shall give public notice... events. (iii) Paleontologic resources with potential to contribute useful educational or scientific... humans, biota, or development of cave resources. (5) Recreational. The cave provides or could...

  20. 222Rn variations in Mystery Cave, Minnesota

    USGS Publications Warehouse

    Lively, R.S.; Krafthefer, B.C.

    1995-01-01

    222Rn concentrations and meteorological parameters were measured at 4- h intervals over a 2-y period in Mystery Cave, southeastern Minnesota. Continuous radon monitors and meteorological sensors connected to data loggers were installed at several locations along commercial tour routes. 222Rn concentrations ranged as high as 25 kBq m-3 in summer and 20 kBq m-3 in winter. Average winter concentrations were lower than summer by at least a factor of two. Seasonal radon variations were correlative with outside air temperatures. During the winter, radon concentrations were observed to fluctuate periodically by factors of 20 or more in under 24 h. Both the long- and short-term variations are correlative with temperature- induced mixing of cave air with surface air.

  1. Palaeolithic paintings. Evolution of prehistoric cave art.

    PubMed

    Valladas, H; Clottes, J; Geneste, J M; Garcia, M A; Arnold, M; Cachier, H; Tisnérat-Laborde, N

    2001-10-04

    Sophisticated examples of European palaeolithic parietal art can be seen in the caves of Altamira, Lascaux and Niaux near the Pyrenees, which date to the Magdalenian period (12,000-17,000 years ago), but paintings of comparable skill and complexity were created much earlier, some possibly more than 30,000 years ago. We have derived new radiocarbon dates for the drawings that decorate the Chauvet cave in Vallon-Pont-d'Arc, Ardèche, France, which confirm that even 30,000 years ago Aurignacian artists, already known as accomplished carvers, could create masterpieces comparable to the best Magdalenian art. Prehistorians, who have traditionally interpreted the evolution of prehistoric art as a steady progression from simple to more complex representations, may have to reconsider existing theories of the origins of art.

  2. Monitoring tropical cave environmental parameters: Implications for palaeoclimate reconstruction

    NASA Astrophysics Data System (ADS)

    Ridley, H.; Baldini, J. U. L.; Prufer, K. M.

    2012-04-01

    This study presents findings from on-going surface and cave environmental monitoring at Yok Balum Cave in southern Belize. Drip hydrochemistry and cave atmosphere dynamics play key roles in calcite deposition, stalagmite growth, and climate proxy signal emplacement. An understanding of daily, seasonal, and inter-annual variability in cave hydrology and atmosphere is therefore critical information for accurately interpreting stalagmite geochemistry in terms of palaeoclimate. Ten month time series datasets of drip rates, cave air PCO2, soil air PCO2, cave air temperature and humidity, drip and surface water δ18O values, and meteorological data are presented here and initial relationships discussed. Initial cave air PCO2 datasets suggest short term (daily) cave ventilation patterns exist which may be superimposed on seasonal-scale variability driven by seasonal rainfall patterns. Rainfall apparently controls soil air PCO2 by controlling soil bioproductivity, so during the rainy season cave air PCO2 may increase in response to an increased CO2 flux into the cave via degassing and flow through micro-fissures. Eight actively growing stalagmites were monitored, indicating that drip hydrology varies spatially within the cave. Temperature and humidity are constant at 23oC and 100% respectively throughout the cave, year round, limiting potential kinetic fractionation of carbon and oxygen isotopes during carbonate precipitation and simplifying interpretations of climate records from stalagmites from the site. Continued environmental monitoring will yield long term datasets which may relate to multi-annual climate phenomena such as the El Niño Southern Oscillation and the North Atlantic Oscillation and provide critical data for interpreting and calibrating the records obtained from Yok Balum stalagmite samples.

  3. Radon levels in Romanian caves: an occupational exposure survey.

    PubMed

    Cucoş Dinu, Alexandra; Călugăr, Monica I; Burghele, Bety D; Dumitru, Oana A; Cosma, Constantin; Onac, Bogdan P

    2016-10-01

    A comprehensive radon survey has been carried out in seven caves located in the western half of Romania's most significant karst regions. Touristic and non-touristic caves were investigated with the aim to provide a reliable distribution of their radon levels and evaluate the occupational exposure and associated effective doses. Radon gas concentrations were measured with long-term diffusion-type detectors during two consecutive seasons (warm and cold). All investigated caves exceed the European Union reference level of radon gas at workplaces (300 Bq/m(3)). The radon concentration in these caves ranges between 53 and 2866 Bq/m(3), reflecting particular cave topography, season-related cave ventilation, and complex tectonic and geological settings surrounding each location. Relatively homogeneous high radon levels occur in all investigated touristic caves and in Tăuşoare and Vântului along their main galleries. Except for Muierii, in all the other caves radon levels are higher during the warm season, compared to the cold one. This suggests that natural cave ventilation largely controls the underground accumulation of radon. The results reported here reveal that the occupational exposure in Urşilor, Vadu Crişului, Tăuşoare, Vântului, and Muierii caves needs to be carefully monitored. The effective doses to workers vary between an average of 0.25 and 4.39 mSv/year depending on the measuring season. The highest values were recorded in show caves, ranging from 1.15 to 6.15 mSv/year, well above the European recommended limit, thus posing a potential health hazard upon cave guides, cavers, and scientists.

  4. Toxicity and Geochemistry of Missouri Cave Stream Sediments

    NASA Astrophysics Data System (ADS)

    Lawler, C. A.; Besser, J.; Wicks, C. M.

    2005-05-01

    Water and sediment quality are among the most important variables affecting the survival of stygobites. In Tumbling Creek Cave, Taney County Missouri the population of the endangered cave snail, Antrobia culveri, has declined significantly over the past decade. The cause of the population decline is unknown but could be related to the quality of streambed sediment in which the cave snail lives. The objective of this study was to determine the toxicity and concentrations of heavy metals in the sediment of Tumbling Creek Cave and five other caves in Missouri. These sediments were analyzed to assess possible point sources from within the recharge areas of the caves and to provide baseline geochemical data to which Tumbling Creek Cave sediments could be compared. Standard sediment toxicity tests and ICP-MS analysis for heavy metals were conducted. Survival and reproduction of the amphipod, Hyalella azteca, did not differ significantly between cave sediments and a control sediment. However the growth of amphipods differed significantly among sites and was significantly reduced in sediments from Tumbling Creek Cave relative to controls. Concentrations of several metals in sediments differed substantially among locations, with elevated levels of zinc and copper occurring in Tumbling Creek Cave. However, none of the measured metal concentrations exceeded sediment quality guidelines derived to predict probable effects on benthic organisms and correlations between sediment metal concentrations and toxicity endpoints were generally weak. While elevated metal levels may play a part in the cave snail's decline, other factors may be of equal or greater importance. Ongoing analyses of persistent organic contaminants and total organic carbon in cave sediments, along with continued water quality monitoring, may provide data that will allow us to better understand this complicated problem.

  5. BELLE STARR CAVE WILDERNESS STUDY AREA, ARKANSAS.

    USGS Publications Warehouse

    Haley, Boyd R.; Stroud, Raymond B.

    1984-01-01

    A mineral survey of the Belle Starr Cave Wilderness Study Area in Arkansas concluded that there is little promise for the occurrence of metallic mineral resources in the area. There is a probable resource potential for small quantities of natural gas. A coal bed that underlies the area contains demonstrated coal resources of about 22. 5 million tons in a bed that averages less than 28 in. thick. Despite its contained coal, this area is not shown as having a coal resource potential.

  6. Cave speleothems as repositories of microbial biosignatures

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; Jurado, Valme; Pereira, Manuel F. C.; Fernández, Octavio; Calaforra, José M.; Dionísio, Amélia; Saiz-Jimenez, Cesareo

    2015-04-01

    The need to better understand the biodiversity, origins of life on Earth and on other planets, and the wide applications of the microbe-mineral interactions have led to a rapid expansion of interest in subsurface environments. Recently reported results indicated signs of an early wet Mars and rather recent volcanic activity which suggest that Mars's subsurface can house organic molecules or traces of microbial life, making the search for microbial life on Earth's subsurface even more compelling. Caves on Earth are windows into the subsurface that harbor a wide variety of mineral-utilizing microorganisms, which may contribute to the formation of biominerals and unusual microstructures recognized as biosignatures. These environments contain a wide variety of redox interfaces and stable physicochemical conditions, which enhance secondary mineral precipitation and microbial growth under limited organic nutrient inputs. Enigmatic microorganisms and unusual mineral features have been found associated with secondary mineral deposits or speleothems in limestone caves and lava tubes. In this study, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray spectroscopy (EDS) analyses were conducted on cave speleothem samples to assess microbe-mineral interactions, evaluate biogenicity, as well as to describe unusual mineral formations and microbial features. Microbial mats, extracellular polymeric substances, tubular empty sheaths, mineralized cells, filamentous fabrics, as well as "cell-sized" etch pits or microborings produced by bacterial cells were observed on minerals. These features evidence microbe-mineral interactions and may represent mineralogical signatures of life. We can thus consider that caves on Earth are plausible repositories of terrestrial biosignatures where we can look for microbial signatures. Acknowledgments: AZM acknowledges the support from the Marie Curie Intra-European Fellowship within the 7th European Community Framework

  7. Primary melanoma of Meckel's cave: case report.

    PubMed

    Falavigna, Asdrubal; Borba, Luis A B; Ferraz, Fernando Antonio Patriani; Almeida, Giovana Camargo de; Krindges Júnior, José Valentim

    2004-06-01

    We present a case of trigeminal neuralgia with cranial normal magnetic resonance image (MRI) and computed tomography. The pain was not relieved by carbamazepine and microvascular decompression surgery was done. After two months the pain was similar to the condition before surgery. At this time, MRI showed an expansive lesion in Meckel's cave that was treated with radical resection by extra-dural approach. The pathologic examination revealed a primary melanoma. The follow-up after six months did not show abnormalities.

  8. Cave biosignature suites: microbes, minerals, and Mars.

    PubMed

    Boston, P J; Spilde, M N; Northup, D E; Melim, L A; Soroka, D S; Kleina, L G; Lavoie, K H; Hose, L D; Mallory, L M; Dahm, C N; Crossey, L J; Schelble, R T

    2001-01-01

    Earth's subsurface offers one of the best possible sites to search for microbial life and the characteristic lithologies that life leaves behind. The subterrain may be equally valuable for astrobiology. Where surface conditions are particularly hostile, like on Mars, the subsurface may offer the only habitat for extant lifeforms and access to recognizable biosignatures. We have identified numerous unequivocally biogenic macroscopic, microscopic, and chemical/geochemical cave biosignatures. However, to be especially useful for astrobiology, we are looking for suites of characteristics. Ideally, "biosignature suites" should be both macroscopically and microscopically detectable, independently verifiable by nonmorphological means, and as independent as possible of specific details of life chemistries--demanding (and sometimes conflicting) criteria. Working in fragile, legally protected environments, we developed noninvasive and minimal impact techniques for life and biosignature detection/characterization analogous to Planetary Protection Protocols. Our difficult field conditions have shared limitations common to extraterrestrial robotic and human missions. Thus, the cave/subsurface astrobiology model addresses the most important goals from both scientific and operational points of view. We present details of cave biosignature suites involving manganese and iron oxides, calcite, and sulfur minerals. Suites include morphological fossils, mineral-coated filaments, living microbial mats and preserved biofabrics, 13C and 34S values consistent with microbial metabolism, genetic data, unusual elemental abundances and ratios, and crystallographic mineral forms.

  9. Cave Biosignature Suites: Microbes, Minerals, and Mars

    NASA Astrophysics Data System (ADS)

    Boston, P. J.; Spilde, M. N.; Northup, D. E.; Melim, L. A.; Soroka, D. S.; Kleina, L. G.; Lavoie, K. H.; Hose, L. D.; Mallory, L. M.; Dahm, C. N.; Crossey, L. J.; Schelble, R. T.

    2001-03-01

    Earth's subsurface offers one of the best possible sites to search for microbial life and the characteristic lithologies that life leaves behind. The subterrain may be equally valuable for astrobiology. Where surface conditions are particularly hostile, like on Mars, the subsurface may offer the only habitat for extant lifeforms and access to recognizable biosignatures. We have identified numerous unequivocally biogenic macroscopic, microscopic, and chemical/geochemical cave biosignatures. However, to be especially useful for astrobiology, we are looking for suites of characteristics. Ideally, "biosignature suites" should be both macroscopically and microscopically detectable, independently verifiable by nonmorphological means, and as independent as possible of specific details of life chemistries - demanding (and sometimes conflicting) criteria. Working in fragile, legally protected environments, we developed noninvasive and minimal impact techniques for life and biosignature detection/characterization analogous to Planetary Protection Protocols. Our difficult field conditions have shared limitations common to extraterrestrial robotic and human missions. Thus, the cave/subsurface astrobiology model addresses the most important goals from both scientific and operational points of view. We present details of cave biosignature suites involving manganese and iron oxides, calcite, and sulfur minerals. Suites include morphological fossils, mineral-coated filaments, living microbial mats and preserved biofabrics, 13C and 34S values consistent with microbial metabolism, genetic data, unusual elemental abundances and ratios, and crystallographic mineral forms.

  10. Measuring radon concentrations and estimating dose in tourist caves.

    PubMed

    Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B; Naranjo Correa, F L

    2015-11-01

    Caves and mines are considered to be places of especial risk of exposure to (222)Rn. This is particularly important for guides and workers, but also for visitors. In the Extremadura region (Spain), there are two cave systems in which there are workers carrying out their normal everyday tasks. In one, visits have been reduced to maintain the conditions of temperature and humidity. The other comprises several caves frequently visited by school groups. The caves were radiologically characterised in order to estimate the dose received by workers or possible hazards for visitors.

  11. Legal protection for caves in the United States

    NASA Astrophysics Data System (ADS)

    Huppert, G. N.

    1995-09-01

    This study reviews significant state and federal laws that can be used to protect karst, caves, and associated unique minerals and biota. The first state cave protection act was passed in Colorado in 1883; unfortunately it was repealed in 1971. From that modest beginning there are now a total of 22 states, Puerto Rico, and the Cherokee Nation that have specific cave protection acts. Most of these have been legislated during the last 20 years. There are a number of laws on the federal level that can be used for cave protection. The most important of these is the Federal Cave Resources Protection Act of 1988, which mandates cave conservation for many federal land management agencies. The Endangered Species Act of 1973 and the Federal Archaeological Resources Protection Act of 1976 can also be of significant use in the conservation of caves on federal land. The effects of these acts are variable. One factor is how important agency officials and law enforcement officers regard caves. It has not been unusual that little was done in the way of protection or prosecution even when the perpetrators have been apprehended. This attitude is changing rapidly primarily because those involved in enforcing the laws have been educated to the uniqueness and values of caves and their contents.

  12. Bacteria and free-living amoeba in the Lascaux Cave.

    PubMed

    Bastian, Fabiola; Alabouvette, Claude; Saiz-Jimenez, Cesareo

    2009-01-01

    The Lascaux Cave was discovered in 1940, and by 1960 it had received up to 1800 daily visitors. In 1963, the cave was closed and in 2001 it was invaded by a Fusarium solani species complex which was treated for four years with benzalkonium chloride. However, Lascaux Cave bacteria have only been poorly investigated. Here we show that the cave is now a reservoir of potential pathogenic bacteria and protozoa which can be found in outbreaks linked to air-conditioning systems and cooling towers in community hospitals and public buildings.

  13. Camshaft bearing arrangement

    SciTech Connect

    Aoi, K.; Ozawa, T.

    1986-06-10

    A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

  14. Detection of diagenetic processes in bones: the case of Arkoudospilia cave, N. Greece

    NASA Astrophysics Data System (ADS)

    Zisi, Nikoleta; Dotsika, Elissavet; Tsoukala, Evangelia; Psomiadis, David

    2010-05-01

    Diagenesis of bone material over geological time is a highly complex phenomenon involving the physical, chemical, histological and mechanical alterations that occur at different time scales from the time of death to present and depend on the local geochemical conditions. The significance of diagenesis and the information that can provide its decoding, led to its study by a variety of physicochemical techniques. Despite serious research efforts, a detailed scenario of bone diagenesis remains elusive. The δ18O of the carbonate material of hydroxyapatite of the bones is though to be a good indicator of the δ18O of the local water precipitation and therefore can be used for palaeoclimatic reconstraction, while δ13C is used for definition of palaeodiet habits. The study of isotopic composition requires the detection of the diagenetic degree, because both δ18O and δ13C can be contaminated by these processes. Stable carbon and oxygen isotope values (δ13C, δ18O) were obtained for structural carbonate in the hydroxy-apatite of bear bones from Arkoudospilia Cave, Pella, N. Greece. The age range of the fossil layers is from 32ka BP to a maximum of 38ka BP (radiocarbon dating). The findings belong to Ursus ingressus, an extinct cave bear. The difficulty in studying an extinct species lies to the fact that it cannot be easily correlated with a present one, so it is impossible to determine the diagenesis by the analytical deviation. However, in order to include the environmental and climatic differences of the past and modern bear habitats, the isotopic composition of the water should be also included in the study. Cave bears are considered to be endemic in Europe. The shortage of data in literature concerning cave bears isotopic analyses in combination with the burden of the difficulties in spotting and sampling such rare materials makes difficult to compare the results of a study. The diet and the physiology of this species are not well known. However the morphology of

  15. CUSHIONED BEARING

    DOEpatents

    Rushing, F.C.

    1960-09-01

    A vibration damping device effective to dampen vibrations occurring at the several critical speeds encountered in the operation of a high-speed centrifuge is described. A self-centering bearing mechanism is used to protect both the centrifuge shaft and the damping mechanism. The damping mechanism comprises spaced-apant, movable, and stationary sleeve members arranged concentrically of a rotating shaft with a fluid maintained between the members. The movable sleeve member is connected to the shaft for radial movement therewith.

  16. Some deep caves in Biokovo Mountain (Croatia)

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Garasic, Davor

    2014-05-01

    The investigation of 3 caves explored more than 1000 meters in depth in the Dinaric karst area in Croatia, has been in progress for a considerable period of time. These are complex speleological features situated in the longest mountain range of the Dinaric karst, i.e. at the Northern Velebit mountain range. In fact, these caves have been studied for over two decades now. The first one is a cave system of Lukina jama (Luke's Cave) - Trojama cave, which has been investigated until the depth of 1421 meters (Jalžić, 2007; Šmida, 1993). Its total length is 3731 meters and a new expedition will soon continue to investigate this pit through speleodiving in siphons. The second greatest cave by depth is Slovačka jama (Slovak Cave), 1320 meters in depth, with cave chanals measuring 5677 meters in total length. The third greatest cave by depth is the Cave system of Velebita, reaching down to 1026 m in depth, with the chanal length of 3176 meters (Bakšić, 2006a; 2006b). However, another 3 speleological sites, which can rightly be added to those deeper than 1000 m, have recently been discovered. These are three caverns that were discovered during construction of the Sveti Ilija Tunnel that passes through Mt. Biokovo, in the Dinaric karst area. These caverns undoubtedly point to the link with the ground surface, while the rock overburden above the tunnel in the zone where the caverns were discovered ranges from 1250 and 1350 meters. Bats from the ground surface were found in the caverns and, according to measurements, they are situated in the depth from 200 and 300 meters below the tunnel level. This would mean that the depth of these newly found caves ranges from 1450 and 1650 m, when observed from the ground surface. There are several hundreds of known caves in Biokovo, and the deepest ones discovered so far are Jama Mokre noge (Wet Feet Cave) 831 m in depth, and Jama Amfora (Amphora Cave) 788 m in depth (Bockovac, 1999; Bakšić & all, 2002; Lacković & all, 2001

  17. Tooling Converts Stock Bearings To Custom Bearings

    NASA Technical Reports Server (NTRS)

    Fleenor, E. N., Jr.

    1983-01-01

    Technique for reworking stock bearings saves time and produces helicopter-rotor bearings ground more precisely. Split tapered ring at one end of threaded bolt expands to hold inside of inner race bearing assembly; nut, at other end of bolt, adjusts amount of spring tension. Piece of hardware grasps bearing firmly without interfering with grinding operation. Operation produces bearing of higher quality than commercially available bearings.

  18. Flash flood events recorded by air temperature changes in caves: A case study in Covadura Cave (SE Spain)

    NASA Astrophysics Data System (ADS)

    Gázquez, Fernando; Calaforra, José María; Fernández-Cortés, Ángel

    2016-10-01

    On 28th September 2012, more than 150 mm rain fell in just two hours in some points of southeastern Spain, triggering intense flash floods that resulted in the death of ten people and widespread material damage. In the gypsum karst of Sorbas, rainfall intensity reached 33 mm/h. Air temperature monitoring in different levels of Covadura Cave, down to 85 m depth, enabled the effect of this extreme episode on the cave microclimate to be evaluated in real time. The cave air temperature increased by between 0.9 and 4.1 °C as a result of water flow into the cavity and intense mixing of air masses, in addition to the displacement of deeper air masses toward shallower levels produced by fast recharge of the surrounding karst aquifer. The lag between peak rainfall intensity and the highest cave air temperature was 5-6 h, indicating the response time of the karst to this rainfall event. No trends with depth were observed, suggesting that water not only flowed in through the main cave entrance but also through secondary accesses and fractures. Furthermore, the size of the cave passages and the intensity of air turbulence generated by waterfalls in the cave played an important role in producing these temperature differences. Even though the rainfall event lasted 10 h, cave air temperature did not return to pre-flash flood values until more than 20 days later. This indicates that, while waterflow through the cave might stop a few hours after the rainfall event, cave air temperature can be affected over a longer period. This can be explained by slow groundwater level decreasing of the surrounding karst aquifer and latent heat liberation produced by moisture condensation on the cave walls. Our results show how continuous monitoring of air temperature in caves can be a useful tool for evaluating the short-term effects of flash floods in subterranean karst systems.

  19. Advances In Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1994-01-01

    NASA technical memorandum reviews state of technology of magnetic bearings, focusing mainly on attractive bearings rather than repulsive, eddy-current, or Lorentz bearings. Attractive bearings offer greater load capacities and preferred for aerospace machinery.

  20. Vegetation productivity during Termination III inferred from a speleothem δ13C record (Ejulve Cave, NE Spain)

    NASA Astrophysics Data System (ADS)

    Perez-Mejías, Carlos; Moreno, Ana; Sancho, Carlos; Bartolomé, Miguel; Stoll, Heather; Cacho, Isabel; Cheng, Hai; Edwards, R. Lawrence

    2016-04-01

    The timing of Termination III, in contrast to TI and TII, is poorly known. Although TIII has been described in pollen sequences from marine cores whose chronology was tuned to orbital parameters, only few continental records with absolute dates have been published. Then, new records of this period are particularly required to test the hypothetical synchronicity at planetary scale of this event or to explore leads and lags between different proxies. Here we present the record of ARTEMISA stalagmite from Ejulve cave (NE Spain) that covers this period with exceptional resolution and constrained by a robust chronological framework obtained from 24 U-Th dates. The largest shift in δ13C record (3 per mil of variation) occurs at 241±2.3 kyr evidencing the TIII inception, in agreement with both Sanbao Cave record in China (within age uncertainties) and the shift to interglacial values of CH4 and CO2 in Antarctica, thus supporting its global synchrony. Interpreting δ13C data in Ejulve Cave is supported by 3 years of monitoring tasks allowing the association of this proxy with vegetation productivity. Thus, more positive values of δ13C, together with higher values in Mg/Ca and Sr/Ca in present-day farmed calcite occurred during dry summer seasons. Besides, these periods are also characterized by the lowest amount of calcite precipitating in the cave. On the contrary, more negative values are obtained during wetter periods, even if they are cooler, showing the highest calcite precipitation rates. During TIII, a spectacular increase in growth rate in the stalagmite is observed, that reaches its maximum (20-30 mm/kyr) during the following 4 kyr. Coherently, both δ13C and trace elements ratios (Mg/Ca and Sr/Ca) mark an increase in humidity at 242 kyr that would last until 227 kyr BP delineating the duration of Stage 7e in this Mediterranean region. Other dry events highlighted by this record are shown at 247 kyr, 245-243 kyr and 221-219 kyr BP suggesting periods of forest

  1. Monitoring of Radon in Tourist Part of Skocjan Caves

    NASA Astrophysics Data System (ADS)

    Debevec Gerjevic, Vanja; Jovanovic, Peter

    2010-05-01

    Due to their exceptional significance for cultural and natural heritage, the Škocjan Caves were entered on UNESCO's list of natural and cultural world heritage sites in 1986. Park Škocjan Caves is located in South Eastern part of Slovenia. It was established with aim of conserving and protecting exceptional geomorphological, geological and hydrological outstanding features, rare and endangered plant and animal species, paleontological and archaeological sites, ethnological and architectural characteristics and cultural landscape and for the purpose of ensuring opportunities for suitable development, by the National Assembly of the Republic of Slovenia in 1996. Park Škocjan Caves established monitoring that includes caves microclimate parameters: humidity, CO2, wind flow and radon concentration and daughter products. The approach in managing the working place with natural background radiation is complex. Monitoring of Radon has been functioning for more than ten years now. Presentation will show the yearly dynamic observed in the different parts of the caves, related to radon daughter products and other microclimatic data, beside the most convenient measuring technique. Implementing the Slovene legislation in the field of radiation protection, we are obligated to perform special measurements in the caves and also having our guides and workers in the caves regularly examined according to established procedure. The medical exams are performed at Institution of Occupational Safety, Ljubljana in order to monitor the influence of Radon to the workers in the cave. The equivalent dose for each employed person is also established on regular basis and it is part of medical survey of workers in the caves. The survey will be described along with education of the staff working in the caves in the field of radiation protection. An overview of Slovene legislation with practical example on implementation will be demonstrated in the case of Škocjan Caves where the managing

  2. Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary

    PubMed Central

    2008-01-01

    Background Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae) have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. Results We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus) and the American giant short-faced bear (Arctodus simus). The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. Conclusion Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations. PMID:18662376

  3. Monitoring of cave air temperature and humidity in the Niedźwiedzia Cave system (Sudetes, Poland) - a key to understanding tourists activity impact to cave environment

    NASA Astrophysics Data System (ADS)

    Gasiorowski, M.; Hercman, H.

    2012-04-01

    The Niedźwiedzia Cave is located in Śnieżnik Massif (the Easter Sudetes, SW Poland) at 800 m a.s.l. The length of known passages is ~3000 m and denivelation is 69 m. The system is composed of 3 levels of passages and chambers. It is a show cave with ~80,000 visitors every year. In 2010 we started monitoring program of cave air temperature and humidity, drip rate, stable isotopes and Uranium and Polonium content in water in selected sites inside the cave and in its vicinity. Changes in dropping rate in upper level are well correlated with precipitation. However, a response of dripping to rainfall depends on former precipitation frequency and intensity - during the humid period the dripping reacts immediately and after long dry period dripping responses with two-weeks delay. There is not so direct correlation between precipitation and dripping in lower level of the system. Air temperature inside the cave is almost stable in lower level (mean annual ~5.3 °C, and annual variation up to 0.7 °C) and more dynamic in the middle level (mean annual ~6.4 °C, and mean annual amplitude up to 4 °C). Daily and weekly measured changes of cave air temperature demonstrate extremely well correlation with number of visitors. In show cave passages (the middle level of the system) temperature increase 0.1-0.2 °C during every day when the cave is open for tourists and such changes is not observed during days without visitors and in lower level of the system closed for tourists. But even short visits of 3-4 cavers are recorded by temperature sensors exposed in the lower level (~0.02 °C increase). It proves very high sensitivity of cave environment to human activity. This study is funded by the National Science Centre and Higher Education grant no. N N306 131038.

  4. Identifying and Describing a Seismogenic Zone in a Sublevel Caving Mine

    NASA Astrophysics Data System (ADS)

    Abolfazlzadeh, Yousef; Hudyma, Marty

    2016-09-01

    Analysis of caving-induced seismicity can aid in the understanding of rock mass behaviour in the different stages of the caving process. A detailed analysis of caving-induced seismicity at the Telfer sublevel caving mine was undertaken. Interpretation of seismic data in the Telfer mine showed the influence of the major geological features on cave behaviour and helped to identify the phases of cave evolution. Two geological zones with unique seismic characteristics (the M50 and M30 stiff reefs) and four key caving phases (initial undercut blasting, cave initiation, cave propagation and breakthrough) were defined through seismic data analysis. Movement of the seismogenic zone was significantly affected by the stiff reefs within the cave column. Seismic source parameter analysis was used to investigate caving mechanisms at Telfer.

  5. 76 FR 77149 - Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... 501 Authority To Manufacture and Distribute Postage Evidencing Systems AGENCY: Postal Service\\TM... Evidencing Systems (PES) to safeguard customer information and maintain regulatory controls over agents... through Friday, at the Payment Technology office. FOR FURTHER INFORMATION CONTACT: Hank Heren,...

  6. A geochronological approach for cave evolution in the Cantabrian Coast (Pindal Cave, NW Spain)

    USGS Publications Warehouse

    Jimenez-Sanchez, M.; Bischoff, J.L.; Stoll, H.; Aranburu, A.

    2006-01-01

    Some of the oldest speleothems in the North Cantabrian Coast (Spain) are reported for the first time in this work. Pindal Cave is developed at 24 m above sea level, in a karstic massif reaching its highest surface in a marine terrace (rasa) located at 50-64 m above the present sea level. Several phases of evolution were previously recognized into the cave, including block collapse of the roof, episodic flooding and detrital sedimentation, and chemical precipitation of at least four speleothem generations over both alluvial and collapse deposits. Three of these speleothem generations have been dated by U/Th. The first generation yielded ages from 124,2 ?? 1, 5 ka BP to 73,1 ?? 0,9 ka BP, giving a minimum age for the main detritic sediments in the cave. The second one is not dated. The third generation gives an age of 3,71 ?? 0,4 ka BP (mathematically corrected to 2.7 ?? 0.5 ka BP), while for the youngest generation, with actively growing stalagmites in the cave, basal ages of 200 years BP are estimated by counting annual laminae. The data suggest a tentative maximum elevation rate close to 0, 2 mm/yr for the Cantabrian Margin in this area, although further chronological studies will be needed to check this hypothesis. ?? 2006 Gebru??der Borntraeger.

  7. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  8. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  9. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  10. The Oldest Cave Art: An Essay on Giftedness and Excellence.

    ERIC Educational Resources Information Center

    Breen, Maureen; White, David A.

    1996-01-01

    This essay examines issues of giftedness and excellence, beginning with classical references to human striving toward the "good," the attraction of gifted children to quality, and the recent discovery of the oldest known cave art with its manifest excellence. Classroom activities related to cave art and language arts, social studies,…

  11. THE MID-LATITUDE BIODIVERSITY RIDGE IN TERRESTRIAL CAVE FAUNA

    EPA Science Inventory

    The world's obligate cave-dwelling fauna holds considerable promise for biogeographic analysis because it represents a large number of independent evolutionary experiments in isolation in caves and adaptation to subterranean life. We focus on seven north temperate regions of at l...

  12. Radon survey in caves from Mallorca Island, Spain.

    PubMed

    Dumitru, Oana A; Onac, Bogdan P; Fornós, Joan J; Cosma, Constantin; Ginés, Angel; Ginés, Joaquín; Merino, Antoni

    2015-09-01

    This study reports radon concentration in the most representative caves of Mallorca, identifying those in which the recommended action level is exceeded, thus posing health risks. Two show caves (Campanet and Artà) and three non-touristic caves (Font, Drac, Vallgornera) were investigated. Data were collected at several locations within each cave for three different periods, from March 2013 to March 2014. Except for Vallgornera, where only one monitoring period was possible, and Artà in which low values were recorded throughout the year, a clear seasonal variability, with higher values during the warm seasons and lower during winter time is prominent. Radon concentrations differed markedly from one cave to another, as well as within the same cave, ranging from below detection limit up to 3060 Bq·m(-3). The results of this study have significant practical implications, making it possible to provide some recommendation to cave administrators and other agencies involved in granting access to the investigated caves.

  13. Biotechnological potential of Actinobacteria from Canadian and Azorean volcanic caves.

    PubMed

    Riquelme, Cristina; Enes Dapkevicius, Maria de Lurdes; Miller, Ana Z; Charlop-Powers, Zachary; Brady, Sean; Mason, Cohord; Cheeptham, Naowarat

    2017-01-01

    Caves are regarded as extreme habitats with appropriate conditions for the development of Actinobacteria. In comparison with other habitats, caves have not yet been the target of intensive screening for bioactive secondary metabolites produced by actinomycetes. As a primary screening strategy, we conducted a metagenomic analysis of the diversity and richness of a key gene required for non-ribosomal peptide (NRP) biosynthesis, focusing on cave-derived sediments from two Canadian caves (a lava tube and a limestone cave) to help us predict whether different types of caves may harbor drug-producing actinobacteria. Using degenerate PCR primers targeting adenylation domains (AD), a conserved domain in the core gene in NRP biosynthesis, a number of amplicons were obtained that mapped back to biomedically relevant NRP gene cluster families. This result guided our culture-dependent sampling strategy of actinomycete isolation from the volcanic caves of Canada (British Columbia) and Portugal (Azores) and subsequent characterization of their antibacterial and enzymatic activities. Multiple enzymatic and antimicrobial activities were identified from bacterial of the Arthrobacter and Streptomyces genera demonstrating that actinomycetes from volcanic caves are promising sources of antibacterial, antibiofilm compounds and industrially relevant enzymes.

  14. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Russell Cave National Monument. 7.68 Section 7.68 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument....

  15. Evolution and development in cave animals: from fish to crustaceans

    PubMed Central

    Protas, Meredith; Jeffery, William R.

    2013-01-01

    Cave animals are excellent models to study the general principles of evolution as well as the mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this article, two of the major model systems used to study the evolution and development (evo–devo) of cave animals are described: the teleost fish Astyanax mexicanus and the isopod crustacean Asellus aquaticus. The ways in which these animals match the major attributes expected of an evo–devo cave animal model system are described. For both species, we enumerate the regressive and constructive troglomorphic traits that have evolved during their adaptation to cave life, the developmental and genetic basis of these traits, the possible evolutionary forces responsible for them, and potential new areas in which these model systems could be used for further exploration of the evolution of cave animals. Furthermore, we compare the two model cave animals to investigate the mechanisms of troglomorphic evolution. Finally, we propose a few other cave animal systems that would be suitable for development as additional models to obtain a more comprehensive understanding of the developmental and genetic mechanisms involved in troglomorphic evolution. PMID:23580903

  16. A burial cave in the western Aleutian Islands, Alaska.

    PubMed

    West, Dixie; Lefèvre, Christine; Corbett, Debra; Crockford, Susan

    2003-01-01

    During the 1998 field season, the Western Aleutians Archaeological and Paleobiological Project (WAAPP) team located a cave in the Near Islands, Alaska. Near the entrance of the cave, the team identified work areas and sleeping/sitting areas surrounded by cultural debris and animal bones. Human burials were found in the cave interior. In 2000, with permission from The Aleut Corporation, archaeologists revisited the site. Current research suggests three distinct occupations or uses for this cave. Aleuts buried their dead in shallow graves at the rear of the cave circa 1,200 to 800 years ago. Aleuts used the front of the cave as a temporary hunting camp as early as 390 years ago. Finally, Japanese and American military debris and graffiti reveal that the cave was visited during and after World War II. Russian trappers may have also taken shelter there 150 to 200 years ago. This is the first report of Aleut cave burials west of the Delarof Islands in the central Aleutians.

  17. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  18. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  19. Evolution and development in cave animals: from fish to crustaceans.

    PubMed

    Protas, Meredith; Jeffery, William R

    2012-01-01

    Cave animals are excellent models to study the general principles of evolution as well as the mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this article, two of the major model systems used to study the evolution and development (evo-devo) of cave animals are described: the teleost fish Astyanax mexicanus and the isopod crustacean Asellus aquaticus. The ways in which these animals match the major attributes expected of an evo-devo cave animal model system are described. For both species, we enumerate the regressive and constructive troglomorphic traits that have evolved during their adaptation to cave life, the developmental and genetic basis of these traits, the possible evolutionary forces responsible for them, and potential new areas in which these model systems could be used for further exploration of the evolution of cave animals. Furthermore, we compare the two model cave animals to investigate the mechanisms of troglomorphic evolution. Finally, we propose a few other cave animal systems that would be suitable for development as additional models to obtain a more comprehensive understanding of the developmental and genetic mechanisms involved in troglomorphic evolution.

  20. Guanophilic fungi in three caves of southwestern Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifty species of guanophilic (bat guano-loving) fungi were isolated from field-collected samples within three caves in south-western Puerto Rico; most were mitosporic fungi (23 species). The caves studied were Cueva La Tuna (Cabo Rojo), Cueva de Malano (Sistema de Los Chorros, San Germán), and Cuev...

  1. Aspergillosis of the Petrous Apex and Meckel's Cave.

    PubMed

    Ederies, Ash; Chen, Joseph; Aviv, Richard I; Pirouzmand, Farhad; Bilbao, Juan M; Thompson, Andrew L; Symons, Sean P

    2010-05-01

    Cranial cerebral aspergillosis is a rare entity in immunocompetent patients. Invasive disease involving the petrous apex and Meckel's cave has rarely been described. We present a case of localized invasive petrous apical and Meckel's cave disease in an immunocompetent patient who presented with hemicranial neuralgic pain.

  2. Intratentorial lipomas with Meckel's cave and cerebellopontine angle extension.

    PubMed

    Ruocco, M J; Robles, H A; Rao, K C; Armonda, R A; Ondra, S L

    1995-08-01

    An unusual case of bilateral intratentorial lipomas with extension into Meckel's caves and the cerebellopontine angle is described. Surgical and histopathologic correlation demonstrate that the lipoma encased the trigeminal nerve in Meckel's caves. The origin of the lipoma from the anteromedial margins of the tentorium is discussed and correlated with a recently proposed theory for the development of intracranial lipomas.

  3. Meckel's cave epidermoid with trigeminal neuralgia: CT findings.

    PubMed

    Kapila, A; Steinbaum, S; Chakeres, D W

    1984-12-01

    An epidermoid tumor of Meckel's cave was found in a middle-aged woman with trigeminal neuralgia. On CT the lesion had negative attenuation numbers of fat and extended from an expanded Meckel's cave through the porous trigeminus into the ambient and cerebellopontine angle cisterns. Surgical excision provided relief of the patient's trigeminal neuralgia.

  4. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Reporting Postage Evidencing System security... security weaknesses. (a) For purposes of this section, provider refers to the Postage Evidencing System... Evidencing System model subject to each such method. Potential security weaknesses include but are...

  5. 39 CFR 501.9 - Demonstration or test Postage Evidencing Systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... demonstration or test Postage Evidencing System must be recorded as such on internal provider inventory records... Postage Evidencing System must remain under the provider's direct control. A demonstration or test Postage... 39 Postal Service 1 2011-07-01 2011-07-01 false Demonstration or test Postage Evidencing...

  6. 39 CFR 501.14 - Postage Evidencing System inventory control processes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Postage Evidencing System inventory control... control processes. (a) Each authorized provider of Postage Evidencing Systems must permanently hold title...) To ensure adequate control over Postage Evidencing Systems, plans for the following processes must...

  7. 76 FR 74753 - Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... governing the inventory control processes of Postage Evidencing Systems (PES) provided to customers by....14 Postage Evidencing System inventory control processes. (a) Each authorized provider of Postage... custody and control of Postage Evidencing Systems and must specifically authorize in writing the...

  8. 39 CFR 501.8 - Postage Evidencing System test and approval.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.8 Postage Evidencing System test and approval. (a) To... Systems regardless of whether the provider is currently authorized by the Postal Service to distribute... approval is granted to manufacture and/or distribute a Postage Evidencing System, no change affecting...

  9. 77 FR 23618 - Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ... 501 Authority To Manufacture and Distribute Postage Evidencing Systems AGENCY: Postal Service TM...--AUTHORIZATION TO MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS 1. The authority citation for 39 CFR part... Postage Evidencing Systems that it manufactures or distributes, except those purchased by the...

  10. Founder effects initiated rapid species radiation in Hawaiian cave planthoppers.

    PubMed

    Wessel, Andreas; Hoch, Hannelore; Asche, Manfred; von Rintelen, Thomas; Stelbrink, Björn; Heck, Volker; Stone, Fred D; Howarth, Francis G

    2013-06-04

    The Hawaiian Islands provide the venue of one of nature's grand experiments in evolution. Here, we present morphological, behavioral, genetic, and geologic data from a young subterranean insect lineage in lava tube caves on Hawai'i Island. The Oliarus polyphemus species complex has the potential to become a model for studying rapid speciation by stochastic events. All species in this lineage live in extremely similar environments but show strong differentiation in behavioral and morphometric characters, which are random with respect to cave age and geographic distribution. Our observation that phenotypic variability within populations decreases with increasing cave age challenges traditional views on founder effects. Furthermore, these cave populations are natural replicates that can be used to test the contradictory hypotheses. Moreover, Hawaiian cave planthoppers exhibit one of the highest speciation rates among animals and, thus, radically shift our perception on the evolutionary potential of obligate cavernicoles.

  11. Founder effects initiated rapid species radiation in Hawaiian cave planthoppers

    PubMed Central

    Wessel, Andreas; Hoch, Hannelore; Asche, Manfred; von Rintelen, Thomas; Stelbrink, Björn; Heck, Volker; Stone, Fred D.; Howarth, Francis G.

    2013-01-01

    The Hawaiian Islands provide the venue of one of nature’s grand experiments in evolution. Here, we present morphological, behavioral, genetic, and geologic data from a young subterranean insect lineage in lava tube caves on Hawai‘i Island. The Oliarus polyphemus species complex has the potential to become a model for studying rapid speciation by stochastic events. All species in this lineage live in extremely similar environments but show strong differentiation in behavioral and morphometric characters, which are random with respect to cave age and geographic distribution. Our observation that phenotypic variability within populations decreases with increasing cave age challenges traditional views on founder effects. Furthermore, these cave populations are natural replicates that can be used to test the contradictory hypotheses. Moreover, Hawaiian cave planthoppers exhibit one of the highest speciation rates among animals and, thus, radically shift our perception on the evolutionary potential of obligate cavernicoles. PMID:23696661

  12. Evidenced-based practice: priorities and implementation strategies.

    PubMed

    Ahrens, Tom

    2005-01-01

    Evidenced-based practice (EBP) should be a driving force behind establishing optimal clinical practices. Recently, clinicians and hospitals have started efforts to introduce key EBP. These efforts hold the potential to improve patient outcomes and reduce costs. However, many practices need updating with EBP. Which ones should be chosen? While practices often vary in terms of importance for each hospital, some changes in practice are likely to have a better return on the investment (ROI). Two key areas affecting most hospitals are practices associated with high costs and increased mortality. In critical care areas, these two key areas often involve addressing outlier management and severe sepsis. In addition, the recognition of the need for the change is only one step in ensuring EBP. To ensure EBP is implemented, clinical leaders who will ensure that the new practice standards are being utilized are necessary. Fortunately, many hospitals have strong leaders. The advanced practice nurse (APN) is one such leader. The APN is often in a unique position to help recognize, prioritize, and implement EBP into the hospitals culture. This article illustrates steps in making EBP a reality by highlighting the management of outliers and severe sepsis and the implementation strategies for these conditions.

  13. THEMIS observes possible cave skylights on Mars

    USGS Publications Warehouse

    Cushing, G.E.; Titus, T.N.; Wynne, J.J.; Christensen, P.R.

    2007-01-01

    Seven possible skylight entrances into Martian caves were observed on and around the flanks of Arsia Mons by the Mars Odyssey Thermal Emission Imaging System (THEMIS). Distinct from impact craters, collapse pits or any other surface feature on Mars, these candidates appear to be deep dark holes at visible wavelengths while infrared observations show their thermal behaviors to be consistent with subsurface materials. Diameters range from 100 m to 225 m, and derived minimum depths range between 68 m and 130 m. Most candidates seem directly related to pitcraters, and may have formed in a similar manner with overhanging ceilings that remain intact. Copyright 2007 by the American Geophysical Union.

  14. Adenocarcinoma of Meckel's cave: case report.

    PubMed

    Tacconi, L; Arulampalam, T; Johnston, F; Symon, L

    1995-12-01

    A rare localization of adenocarcinoma in Meckel's cave is reported in a 58-year-old woman, who had a 5-month history of pain and altered sensation in the second division of the left trigeminal nerve. Removal of the lesion was achieved by a subtemporal route. Histology showed this to be an adenocarcinoma. The patient underwent investigations for a primary tumor; the investigations were all negative, and the patient was subsequently treated with a course of radiotherapy. At 4-month follow-up, there was no evidence of recurrence, and she remains symptomatically well. The various mechanisms of secondary localization are discussed.

  15. Fluid lubricated bearing construction

    DOEpatents

    Dunning, John R.; Boorse, Henry A.; Boeker, Gilbert F.

    1976-01-01

    1. A fluid lubricated thrust bearing assembly comprising, in combination, a first bearing member having a plain bearing surface, a second bearing member having a bearing surface confronting the bearing surface of said first bearing member and provided with at least one spiral groove extending inwardly from the periphery of said second bearing member, one of said bearing members having an axial fluid-tight well, a source of fluid lubricant adjacent to the periphery of said second bearing member, and means for relatively rotating said bearing members to cause said lubricant to be drawn through said groove and to flow between said bearing surfaces, whereby a sufficient pressure is built up between said bearing surfaces and in said well to tend to separate said bearing surfaces.

  16. Fossil invertebrates records in cave sediments and paleoenvironmental assessments: a study of four cave sites from Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2015-06-01

    Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new for science, and most of them are indicative for either warm/cold stages or dry/wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures, and hydraulic regimes could be gathered. This paper analyses the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  17. Geomorphological maps and 3d models in cave research

    NASA Astrophysics Data System (ADS)

    Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María

    2013-04-01

    Cave geomorphological processes and features can be studied by geomorphological maps although topographic maps, aerial photos and GPS are not available. Methods in cave geomorphological mapping are conditioned by cave environment configuration, the need of using speleological techniques, and limitations arising from the projection of the 3D data from the cave to a 2D plan. Some of our previous works in the Cantabrian Mountains and Cantabrian Coast (NW Spain) established the approach of the design of cave geomorphological maps and its legend. Today we are improving the display of cave process combining geomorphological maps and 3d models based on the experience obtained from the research of one cave from the Cantabrian Coast and four caves in the Picos de Europa National Park (funded by GEOCAVE project, Spanish National Parks Agency). The five caves are developed in Carboniferous limestone affected by faults and thrusts. The method of work includes: 1) the elaboration of the cave survey at 1:50 to 1:500 scale; 2) the check of the cave survey of three caves by closed loops; 3) the mapping of cave features based on the performed survey; 4) the 3d modeling of the caves approximating each survey shoot by an octagonal prism; and 5) the implementation and management of the survey and geomorphological map in a Geographic Information System. Based on the survey, the cavities are small caves to deep alpine shafts with 281 to 4,438 m length and up to 738 m deep. The precision of the cave maps only could be estimated in two caves at a cavity scale, displaying both of them a 2.49 % error. The prisms of the 3d model was classified into four groups according to the morphology of the cave passage: 1) canyons, 2) phreatic and epiphreatic tubes, 3) soutirage conduits, 4) mixed forms composed by phreatic and epiphreatic tubes modified by fluvial incision, 5) pitches and 6) irregular passages enlarged strongly by gravity process. According to our previous works geomorphological

  18. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... contains species or subspecies of flora or fauna native to caves, or are sensitive to disturbance, or are found on State or Federal sensitive, threatened, or endangered species lists. (2) Cultural. The cave... humans, biota, or development of cave resources. (5) Recreational. The cave provides or could...

  19. Soft-bottom crustacean assemblages in Mediterranean marine caves: the cave of Cerro Gordo (Granada, Spain) as case study

    NASA Astrophysics Data System (ADS)

    Navarro-Barranco, C.; Guerra-García, J. M.; Sánchez-Tocino, L.; García-Gómez, J. C.

    2012-12-01

    Although marine caves are priority conservation areas according to the Directive 92/43/CEE of the European Community, there is a lack of studies dealing with their soft-bottom communities. For a case study, we selected the Cerro Gordo cave at 15 m depth. Three different zones were defined: a semi-dark 25-m long entrance area, a dark intermediate area of 35 m, and the final zone at 90 m from the entrance. Sediment samples were taken from these zones as well as from outside the cave (control) by SCUBA diving. Six rectangular cores of 10 × 250 cm2 were collected in each site for macrofaunal study, and three more replicates were taken to analyze physico-chemical parameters. The granulometry showed a clear gradient from medium sands outside the cave to silt and clay in the inner zone. Measurements of the crustacean assemblages showed that the number of species and abundance were significantly higher outside the cave (30-40 species, >4,000 ind m-2) than inside (5-10 species, <1,000 ind m-2). Multivariate analyses showed a clear difference in species composition between outside and inside the cave. Caprellids, tanaids, cumaceans, and decapods were only found outside the cave, while gammarids and isopods were present both outside and inside the cave. The gammarid Siphonoecetes sabatieri and the tanaid Apseudes latreilli were the dominant species outside the cave, while the gammarids Harpinia pectinata, Harpinia crenulata, and Harpinia ala were dominant inside. The present study represents an increase in depth range and geographic distribution for Kupellonura mediterranea and Monoculodes packardi. This is the first description of soft-bottom crustacean communities from submarine caves of southern Spain.

  20. Seven Possible Cave Skylights on Mars

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1

    Seven very dark holes on the north slope of a Martian volcano have been proposed as possible cave skylights, based on day-night temperature patterns suggesting they are openings to subsurface spaces. These six excerpts of images taken in visible-wavelength light by the Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter show the seven openings. Solar illumination comes from the left in each frame. The volcano is Arsia Mons, at 9 degrees south latitude, 239 degrees east longitude.

    The features have been given informal names to aid comparative discussion (see figure 1). They range in diameter from about 100 meters (328 feet) to about 225 meters (738 feet). The candidate cave skylights are (A) 'Dena,' (B) 'Chloe,' (C) 'Wendy,' (D) 'Annie,' (E) 'Abby' (left) and 'Nikki,' and (F) 'Jeanne.' Arrows signify north and the direction of illumination.

    Mars Odyssey is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The orbiter's Thermal Emission Imaging System was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif., and is operated by Arizona State University.

  1. Vision-mediated interaction with the Nottingham caves

    NASA Astrophysics Data System (ADS)

    Ghali, Ahmed; Bayomi, Sahar; Green, Jonathan; Pridmore, Tony; Benford, Steve

    2003-05-01

    The English city of Nottingham is widely known for its rich history and compelling folklore. A key attraction is the extensive system of caves to be found beneath Nottingham Castle. Regular guided tours are made of the Nottingham caves, during which castle staff tell stories and explain historical events to small groups of visitors while pointing out relevant cave locations and features. The work reported here is part of a project aimed at enhancing the experience of cave visitors, and providing flexible storytelling tools to their guides, by developing machine vision systems capable of identifying specific actions of guides and/or visitors and triggering audio and/or video presentations as a result. Attention is currently focused on triggering audio material by directing the beam of a standard domestic flashlight towards features of interest on the cave wall. Cameras attached to the walls or roof provide image sequences within which torch light and cave features are detected and their relative positions estimated. When a target feature is illuminated the corresponding audio response is generated. We describe the architecture of the system, its implementation within the caves and the results of initial evaluations carried out with castle guides and members of the public.

  2. The fungal colonisation of rock-art caves: experimental evidence.

    PubMed

    Jurado, Valme; Fernandez-Cortes, Angel; Cuezva, Soledad; Laiz, Leonila; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Saiz-Jimenez, Cesareo

    2009-09-01

    The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France-both included in the UNESCO World Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity.

  3. The fungal colonisation of rock-art caves: experimental evidence

    NASA Astrophysics Data System (ADS)

    Jurado, Valme; Fernandez-Cortes, Angel; Cuezva, Soledad; Laiz, Leonila; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Saiz-Jimenez, Cesareo

    2009-09-01

    The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France—both included in the UNESCO World Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity.

  4. Oxygen Isotope and Microtextural Biosignatures of Hydroxylapatite in Karst Caves of South Korea

    NASA Astrophysics Data System (ADS)

    Chang, S.; Blake, R. E.; Kim, S.

    2006-05-01

    Hydroxylapatite is precipitating in restricted areas of bat habitats in three karst caves (Gosu, Sungryu, and Ssang caves) in S. Korea. It covers the surfaces of carbonate speleothem and host rock forming a 0.1 to 0.5 mm thick crust. In order to elucidate the process of formation of this hydroxylapatite crust, the O isotope composition of phosphate (δ18OP), in the crust and in bat guano, as well as the O isotope compositions of calcite carbonate (δ18OC) in speleothems, and of dripping water (δ18OW) were determined together with mineralogical and textural analyses. The δ18OP values of the crust (approx. 13 permil) are between δ18OP values of bat guano (approx. 21 permil) and δ18OW values of dripping water (approx. -9.5 permil). These δ18O values and a close relation between crust distribution and bat habitat indicate that bat excretion provides phosphate for formation of the hydroxylapatite crust. The δ18OP values of the crust are in temperature-dependent isotopic equilibrium with dripping water. This suggests that the phosphate has been metabolized and has undergone oxygen isotope exchange with dripping water by enzyme-catalyzed reactions at low temperatures (13 to 16°C). The δ18OC values of speleothem calcite below the crust are approx. 9 permil higher than the δ18OP values of the crust. This suggests that both speleothem and crust have formed in oxygen isotopic equilibrium with the dripping water as a result of enzyme-catalyzed reactions. Electron microscopy shows that sulfur-bearing filamentous bacteria are distributed on and within the crust. Also, four different microtextures (colloform, sea- and-island, cellular, and reticulate textures) are observed in the crust, and are produced by the distribution patterns of bacteria. Thus, both isotopic and microtextural signatures reflect bacterially-mediated biomineralization of hydroxylapatite in karst cave ecosystems.

  5. Monitoring of Bunker Cave (NW Germany): Assessing the complexity of cave environmental parameters

    NASA Astrophysics Data System (ADS)

    Riechelmann, Dana Fc; Schröder-Ritzrau, Andrea; Scholz, Denis; Spötl, Christoph; Richter, Detlev K.; Mangini, Augusto

    2010-05-01

    Bunker Cave (N 51° 22'03', E 7° 39'53') is located in the Rhenish Slate Mountains in the western part of Germany and is part of a giant cave system in the area of Iserlohn (Hammerschmidt et al., 1995).As part of the DAPHNE (Dated Speleothems - archives of the paleoenvironment) project Bunker Cave is being monitored since the end of 2006. The ongoing monitoring program is performed on a monthly base. Surface climate parameters are measured and samples of rain water, cave air, drip water at eight different drip sites and modern calcite precipitates from watch glasses placed beneath drip sites are collected. Data sets include temperature, precipitation, calculated infiltration, drip rates, electric conductivity, pH, alkalinity, cations, anions and stable isotopes. Bunker Cave shows a constant temperature throughout the year. Active calcite precipitation is higher in winter than in summer, which is due to lower cave pCO2 in winter. The generally low pCO2 values, however, support almost continuous calcite precipitation throughout the whole year. Drip water δ18O values reflect the mean annual isotopic composition of the rainfall in this area with no or less contribution of the summer rain. The slope of the MWL for local precipitation is close to the slope of both the global MWL and the local MWL at the nearby station Bad Salzuflen. The karst aquifer is well mixed as shown by the uniform drip water δ18O values. Hence, the site is well suited to detect multi-annual climate trends using stalagmite stable isotope records. In order to test the potential influence of kinetic isotope fractionation on the stable isotope signals at Bunker Cave, stable isotope data of modern calcite precipitated on watch glasses were compared to predicted values. Comparison of the δ18O values of in situ modern calcite precipitates with the δ18O values expected from equilibrium isotope fractionation suggests a small kinetic influence, which is probably related to the variability in drip rate

  6. Do cave features affect underground habitat exploitation by non-troglobite species?

    NASA Astrophysics Data System (ADS)

    Lunghi, Enrico; Manenti, Raoul; Ficetola, Gentile Francesco

    2014-02-01

    Many biospeleological studies focus on organisms that are exclusive inhabitants of the subterranean realm, but organisms that are not obligate cave-dwellers are frequent in caves, and may account for a substantial portion of biomass. Moreover, several taxa that are usually epigeous are regularly found inside caves, but for most of them it is unknown whether they accidentally enter them, or whether they actively select caves for specific environmental features. In this study we analysed the community of non-strict cave-dwelling organisms (amphibians, gastropods, spiders and orthopterans) in 33 caves from Central Italy, to assess how environmental factors determine community structure. Cave features strongly affected the distribution of the taxa considered. The combined effect of cave morphology and microclimate explained nearly 50% of the variation of community structure. Most of community variation occurred along a gradient from deep, dark and humid caves, to dry caves with wider entrances and extended photic areas. Most of species were associated with humid, deep and dark caves. Most of the non-troglobiont amphibians and invertebrates did not occur randomly in caves, but were associated to caves with specific environmental features. Analysing relationships between cave-dwelling species and environmental variables can allow a more ecological and objective classification of cave-dwelling organisms.

  7. Late Neandertals and the intentional removal of feathers as evidenced from bird bone taphonomy at Fumane Cave 44 ky B.P., Italy

    PubMed Central

    Peresani, Marco; Fiore, Ivana; Gala, Monica; Romandini, Matteo; Tagliacozzo, Antonio

    2011-01-01

    A large and varied avifaunal bone assemblage from the final Mousterian levels of Grotta di Fumane, northern Italy, reveals unusual human modifications on species that are not clearly relatable to feeding or utilitarian uses (i.e., lammergeier, Eurasian black vulture, golden eagle, red-footed falcon, common wood pigeon, and Alpine chough). Cut, peeling, and scrape marks, as well as diagnostic fractures and a breakthrough, are observed exclusively on wings, indicating the intentional removal of large feathers by Neandertals. The species involved, the anatomical elements affected, and the unusual type and location of the human modifications indicate an activity linked to the symbolic sphere and the behavioral modernity of this European autochthonous population. PMID:21368129

  8. ComputerApplications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Centerr (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provided general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

  9. Computer Applications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall SPace Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

  10. ComputerApplications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Center (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability providedgeneral visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

  11. Clumped isotope thermometry of cryogenic cave carbonates

    NASA Astrophysics Data System (ADS)

    Kluge, Tobias; Affek, Hagit P.; Zhang, Yi Ge; Dublyansky, Yuri; Spötl, Christoph; Immenhauser, Adrian; Richter, Detlev K.

    2014-02-01

    Freezing of cave pool water that is increasingly oversaturated with dissolved carbonate leads to precipitation of a very specific type of speleothems known as cryogenic cave carbonates (CCC). At present, two different environments for their formation have been proposed, based on their characteristic carbon and oxygen isotope ratios. Rapidly freezing thin water films result in the fast precipitation of fine-grained carbonate powder (CCCfine). This leads to rapid physicochemical changes including CO2 degassing and CaCO3 precipitation, resulting in significantly 13C-enriched carbonates. Alternatively, slow carbonate precipitation in ice-covered cave pools results in coarse crystalline CCC (CCCcoarse) yielding strongly 18O-depleted carbonate. This is due to the formation of relatively 18O-enriched ice causing the gradual depletion of 18O in the water from which the CCC precipitates. Cryogenic carbonates from Central European caves were found to have been formed primarily during the last glacial period, specifically during times of permafrost thawing, based on the oxygen isotope ratios and U-Th dating. Information about the precise conditions of CCCcoarse formation, i.e. whether these crystals formed under equilibrium or disequilibrium conditions with the parent fluid, however, is lacking. An improved understanding of CCCcoarse formation will increase the predictive value of this paleo-permafrost archive. Here we apply clumped isotopes to investigate the formation conditions of cryogenic carbonates using well-studied CCCcoarse from five different cave systems in western Germany. Carbonate clumped isotope measurements yielded apparent temperatures between 3 and 18 °C and thus exhibit clear evidence of isotopic disequilibrium. Although the very negative carbonate δ18O values can only be explained by gradual freezing of pool water accompanied by preferential incorporation of 18O into the ice, clumped isotope-derived temperatures significantly above expected freezing

  12. Further constraints on the Chauvet cave artwork elaboration

    NASA Astrophysics Data System (ADS)

    Sadier, Benjamin; Delannoy, Jean-Jacques; Benedetti, Lucilla; Bourlès, Didier L.; Jaillet, Stéphane; Geneste, Jean-Michel; Lebatard, Anne-Elisabeth; Arnold, Maurice

    2012-05-01

    Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419-479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908-917]. The presented 36Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution.

  13. Further constraints on the Chauvet cave artwork elaboration

    PubMed Central

    Sadier, Benjamin; Delannoy, Jean-Jacques; Benedetti, Lucilla; Bourlès, Didier L.; Jaillet, Stéphane; Geneste, Jean-Michel; Lebatard, Anne-Elisabeth; Arnold, Maurice

    2012-01-01

    Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419–479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908–917]. The presented 36Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution. PMID:22566649

  14. Unexplored diversity and conservation potential of neotropical hot caves.

    PubMed

    Ladle, Richard J; Firmino, João V L; Malhado, Ana C M; Rodríguez-Durán, Armando

    2012-12-01

    The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot-cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat-generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism.

  15. The biogeochemistry of anchialine caves: Progress and possibilities

    USGS Publications Warehouse

    Pohlman, John W.

    2011-01-01

    Recent investigations of anchialine caves and sinkholes have identified complex food webs dependent on detrital and, in some cases, chemosynthetically produced organic matter. Chemosynthetic microbes in anchialine systems obtain energy from reduced compounds produced during organic matter degradation (e.g., sulfide, ammonium, and methane), similar to what occurs in deep ocean cold seeps and mud volcanoes, but distinct from dominant processes operating at hydrothermal vents and sulfurous mineral caves where the primary energy source is mantle derived. This review includes case studies from both anchialine and non-anchialine habitats, where evidence for in situ chemosynthetic production of organic matter and its subsequent transfer to higher trophic level metazoans is documented. The energy sources and pathways identified are synthesized to develop conceptual models for elemental cycles and energy cascades that occur within oligotrophic and eutrophic anchialine caves. Strategies and techniques for testing the hypothesis of chemosynthesis as an active process in anchialine caves are also suggested.

  16. Organochlorine residues in bat guano from nine Mexican caves, 1991

    USGS Publications Warehouse

    Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

    1995-01-01

    Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering residues from use of DDT years ago in the Ojuela area of perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbamate insecticides now in extensive use are unknown.

  17. Organochlorine residues in bat guano from nine Mexican caves, 1991

    USGS Publications Warehouse

    Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

    1995-01-01

    Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering resides from use of DDT years ago in the Ojuela area or perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p'-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbonate insecticides now in extensive use are unknown.

  18. Partnerships in Sustainable Transportation: Mammoth Cave National Park

    SciTech Connect

    Carson, Vickie

    2016-07-13

    This video takes a look at how the U.S. Department of Energy is helping to support a fleet of alternative fuel vehicles at Mammoth Cave National Park, reducing carbon emissions and preserving the park's natural beauty.

  19. 5. Photographic copy of historic photograph (from Wind Cave National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photographic copy of historic photograph (from Wind Cave National Park), photographer unknown, date unknown. Route 87, Beaver Creek Bridge, elevation. - Beaver Creek Bridge, Hot Springs, Fall River County, SD

  20. Recovery of deceased scuba divers from within flooded subterranean caves.

    PubMed

    Buzzacott, Peter; Nelson, Craig; Hill, Ken; Hires, Lamar

    2017-03-27

    Each year in the US three divers, on average, perish inside flooded caves and their remains require recovery. Recovery is a hazardous undertaking often performed by members of the International Underwater Cave Rescue and Recovery (IUCRR) team, in collaboration with local law enforcement and medical examiners/coroners. Since forming in 1999 the IUCRR have established standard recovery procedures for cave diving fatalities. This article reviews each stage of the recovery; the call out, arrival on site, the search, recording/preserving the evidence, the recovery, the handover and post-recovery record-keeping. A series of five cases highlight the challenges IUCRR divers are trained to face. It is strongly recommended local dive teams do not attempt to recover bodies from within flooded caves. IUCRR divers are trained to utilize a uniform procedure that is acceptable to the local law enforcement Incident Command System.

  1. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    USGS Publications Warehouse

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  2. Partnerships in Sustainable Transportation: Mammoth Cave National Park

    ScienceCinema

    Carson, Vickie

    2016-08-12

    This video takes a look at how the U.S. Department of Energy is helping to support a fleet of alternative fuel vehicles at Mammoth Cave National Park, reducing carbon emissions and preserving the park's natural beauty.

  3. Radon Dose Determination for Cave Guides in Czech Republic

    SciTech Connect

    Thinova, Lenka; Rovenska, Katerina

    2008-08-07

    According to recommended approach there are six (from total of twelve) open-to-public caves in Czech Republic, reaching near to an effective lung-dose of 6mSv/year. A conservative approach for estimating the potential effective lung-dose in caves (or underground) is based on two season's measurements, using solid state alpha track detector (Kodak in plastic diffusion chamber). The obtained dataset is converted into an annual effective dose, in agreement with the ICRP65 recommendation, using the 'cave factor' 1.5. The value of 'cave factor' which depends on the spectrum of aerosol particles, or on the proportional representation of the unattached/attached ratio (6.5 : 93.5 for residential places, 13.6 : 86.4 for caves due to lower concentration of free aerosols) and on the equilibrium factor. Thus conversion factor is 1.5 times higher in comparison with ICRP 65. Is this correct? Because a more precisely determined dose value would have a significant impact on radon remedies, or on restricting the time workers stay underground, a series of measurement was initiated in 2003 with the aim to specify input data, computation and errors in effective dose assessment in each one of the evaluated caves separately. The enhancement of personal dosimetry for underground work places includes a study of the given questions, from the following points of view in each cave: continual radon measurement; regular measurements of radon and its daughters to estimate the equilibrium factor and the presence of free {sup 218}Po; regular indoor air flow measurements to study the location of the radon supply and its transfer among individual areas of the cave; natural radioactive element content evaluation in subsoil and in water inside/outside, a study of the radon sources in the cave; determination of the free fraction from continual unattached and attached fraction measurement (grid and filter); thoron measurement. Air flow measurements provide very interesting information about the origin

  4. High-Resolution Isotopic Monitoring of Cave Air CO2

    NASA Astrophysics Data System (ADS)

    Töchterle, Paul; Dublyansky, Yuri; Mandic, Magda; Stöbener, Nils; Jost, Hj; Spötl, Christoph

    2016-04-01

    This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1 s). The air temperature was independently monitored inside and outside the cave. This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1s). The air temperature was independently monitored inside and outside the cave. The data show two distinct patterns in terms of CO2 concentration and its isotopic composition, which are closely coupled with the temperature difference between the cave interior and the outside atmosphere. This gradient controls the direction of air flow in the cave on a seasonal to synoptic timescale (chimney-type ventilation). The summer circulation is characterised by CO2 closely resembling atmospheric values (pCO2 = 399 ± 12 ppm, δ13C = -8.5 ± 0.7 permil, δ18O = 8.1 ± 2.5 permil). The winter circulation mode features generally higher CO2 concentrations and lower isotopic compositions (pCO2 = 409 ± 14 ppm, δ13C = -10.1 ± 0.7 permil, δ18O = 2.3 ± 1.5 permil). The high temporal resolution of stable isotope data allows tracking cave air ventilation changes, including transient and short-lived ones. Moreover, the data make it possible to address concomitant geochemical processes, such as the input of atmospheric CO2 and the degassing of CO2 from seepage water. These processes would not be possible to quantify without the new generation of laser-based isotope ratio instruments represented by the Delta Ray.

  5. Some Caves in tunnels in Dinaric karst of Croatia

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Garasic, Davor

    2016-04-01

    In the last 50 years during the construction of almost all the tunnels in the Croatian Dinaric Karst thousands of caves have been encountered that represented the major problems during the construction works. Geological features (fissures, folding, faults, etc.) are described in this contribution, together with the hydrogeological conditions (rapid changes in groundwater levels). Special engineering geological exploration and survey of each cave, together with the stabilization of the tunnel ceiling, and groundwater protection actions according to basic engineering geological parameters are also presented. In karst tunneling in Croatia over 150 caves longer than 500 m have been investigated. Several caves are over 300 m deep (St. Ilija tunnel in Biokovo Mt), and 10 are longer than 1000 m (St.Rok tunnel, HE Senj and HE Velebit tunnels in Velebit Mt, Ucka tunnel in Ucka Mt, Mala kapela tunnel in Kapela Mt, caverns in HE Plat tunnel etc). Different solutions were chosen to cross the caves depending on the size and purpose of the tunnels (road, rail, pedestrian tunnel, or hydrotechnical tunnels). This is presentations of interesting examples of ceiling stabilization in big cave chambers, construction of bridges inside tunnels, deviations of tunnels, filling caves, grouting, etc. A complex type of karstification has been found in the cavern at the contact between the Palaeozoic clastic impervious formations and the Mesozoic complex of dolomitic limestones in the Vrata Tunnel and at the contact with flysch in the Učka Tunnel. However, karstification advancing in all directions at a similar rate is quite rare. The need to have the roadway and/or tunnel above water from a spring is the biggest possible engineering-geological, hydrogeological and civil engineering challenge. Significant examples are those above the Jadro spring (Mravinci tunnel) in flysch materials or above the Zvir spring in Rijeka (Katarina tunnel), and in fractured Mesozoic carbonates. Today in Croatian

  6. Geologic history of the Black Hills caves, South Dakota

    USGS Publications Warehouse

    Palmer, Arthur N.; Palmer, Margaret; Paces, James B.

    2016-01-01

    The caves reveal four phases of calcite deposition: eogenetic ferroan calcite (Mississippian replacement of sulfates); white scalenohedra in paleovoids deposited during deep post-Mississippian burial; palisade crusts formed during blockage of springs by Oligocene–Miocene continental sediments; and laminated crusts from late Pleistocene water-table fluctuations. The caves reveal more than 300 m.y. of geologic history and a close relationship to regional geologic events.

  7. Review of Hydraulic Fracturing for Preconditioning in Cave Mining

    NASA Astrophysics Data System (ADS)

    He, Q.; Suorineni, F. T.; Oh, J.

    2016-12-01

    Hydraulic fracturing has been used in cave mining for preconditioning the orebody following its successful application in the oil and gas industries. In this paper, the state of the art of hydraulic fracturing as a preconditioning method in cave mining is presented. Procedures are provided on how to implement prescribed hydraulic fracturing by which effective preconditioning can be realized in any in situ stress condition. Preconditioning is effective in cave mining when an additional fracture set is introduced into the rock mass. Previous studies on cave mining hydraulic fracturing focused on field applications, hydraulic fracture growth measurement and the interaction between hydraulic fractures and natural fractures. The review in this paper reveals that the orientation of the current cave mining hydraulic fractures is dictated by and is perpendicular to the minimum in situ stress orientation. In some geotechnical conditions, these orientation-uncontrollable hydraulic fractures have limited preconditioning efficiency because they do not necessarily result in reduced fragmentation sizes and a blocky orebody through the introduction of an additional fracture set. This implies that if the minimum in situ stress orientation is vertical and favors the creation of horizontal hydraulic fractures, in a rock mass that is already dominated by horizontal joints, no additional fracture set is added to that rock mass to increase its blockiness to enable it cave. Therefore, two approaches that have the potential to create orientation-controllable hydraulic fractures in cave mining with the potential to introduce additional fracture set as desired are proposed to fill this gap. These approaches take advantage of directional hydraulic fracturing and the stress shadow effect, which can re-orientate the hydraulic fracture propagation trajectory against its theoretical predicted direction. Proppants are suggested to be introduced into the cave mining industry to enhance the

  8. Studying microfungi-mineral interactions in sulphide-bearing waste-rock dumps: a 7 years survey in the Libiola mine, North-Eastern Italy

    NASA Astrophysics Data System (ADS)

    Marescotti, P.; Cecchi, G.; Di Piazza, S.; Lucchetti, G.; Zotti, M.

    2015-12-01

    Sulphide-bearing waste-rock dumps represent complex geological systems characterised by high percentages of low-grade mineralisations and non-valuable sulphides (such as pyrite and pyrrhotite). The sulphide oxidation triggers acid mine drainage (AMD) processes and the release of several metals of environmental concern. The severe physicochemical properties of these metal-contaminated environments tend to inhibit soil forming processes and represent an important stress factor for the biotic communities by exerting a strong selective pressure. Some macro- and micro-fungi are pioneer and extremophile organisms, which may survive and tolerate high concentrations of toxic metals in contaminated environments. Many studies show the fungal capability to bioaccumulate, biosorb, and store in their cells a high concentration of ecotoxic metals. A 7 years multidisciplinary survey was carried out in the Libiola sulphide mine. The results evidenced that the waste rock dumps of the area are characterized by an extremely poor flora and a specific mycobiota, due to the soil acidity, high concentration of trace metals, and unavailability or paucity of nutrients and organic matter. Our studies allowed the complete mineralogical, geochemical, and mycological characterization of one of the biggest dumps of the mine. 30 microfungal vital strains were isolated in pure cultures and studied with molecular and morphological approach, for their identification. The results allowed the isolation of some rare and important extremophilic species. Penicillium was the most recurrent genus, together with Trichoderma and Cladosporium. In particular, Penicillium glandicola is a rare species previously isolated from cave or arid environments, whereas P. brevicompactum is one of the most important fungi for metal corrosion. Hence, some bioaccumulation tests allowed to select a Trichoderma harzianum strain efficient to uptake Cu and Ag from pyrite-bearing soils, highlighting its central role in fungal

  9. Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

    NASA Astrophysics Data System (ADS)

    Yang, S.; Shi, Y.

    2015-04-01

    Ice caves exist in locations where annual average temperature in higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively explain the mechanism of formation and preservation of the ice cave, we use Finite Element Method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside, very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, etc. for sustainable development of ice cave as tourism resource. In some other ice caves in China, managers installed air-tight doors at these ice caves entrance intending to "protect" these caves, but this prevent cooling down these caves in winters and these cave ices will entirely melt within tens of years.

  10. Evaluating genetic viability of pronghorn in Wind Cave National Park

    USGS Publications Warehouse

    Jenks, Jonathan A.; Jacques, Christopher N.; Sievers, Jaret D.; Klaver, Robert W.; Bowyer, R. Terry; Roddy, Daniel E.

    2006-01-01

    The pronghorn (Antilocapra americana) was reintroduced into Wind Cave National Park, South Dakota, in 1914 and thus, has inhabited the Park for almost a century. A decline in the population has raised concern for the continued existence of pronghorn inside Wind Cave National Park. Historically, pronghorn numbers reached greater than 300 individuals in the 1960’s but declined to about 30 individuals by 2002. The primary objective of our study was to evaluate genetic characteristics of pronghorn to determine if reduced heterozygosity contributed to the decline of pronghorn in Wind Cave National Park. Microsatellite DNA was collected from 75 pronghorn inhabiting Wind Cave National Park in western South Dakota (n = 11), northwestern South Dakota (n = 33), and southwestern South Dakota (n = 31). Pronghorn in Wind Cave National Park had similar levels of observed heterozygosity (0.473 to 0.594) and low inbreeding coefficients (-0.168 to 0.037) when compared with other populations in western South Dakota. Furthermore, indices of population structure indicated no differentiation occurred among pronghorn populations. Results indicated that genetic variability was not a primary factor in the decline of pronghorn in Wind Cave National Park.

  11. Regressive evolution in the Mexican cave tetra, Astyanax mexicanus.

    PubMed

    Protas, Meredith; Conrad, Melissa; Gross, Joshua B; Tabin, Clifford; Borowsky, Richard

    2007-03-06

    The evolutionary forces driving the reduction of eyes and pigmentation in cave-adapted animals are unknown; Darwin famously questioned the role of natural selection in eye loss in cave fishes: "As it is difficult to imagine that eyes, although useless, could be in any way injurious to animals living in darkness, I attribute their loss wholly to disuse"[1]. We studied the genetics of eye and pigmentation regression in the Mexican cave tetra, Astyanax mexicanus, by mapping and quantitative trait loci (QTL) analysis. We also mapped QTL for the putatively constructive traits of jaw size, tooth number, and numbers of taste buds. The data suggest that eyes and pigmentation regressed through different mechanisms. Cave alleles at every eye or lens QTL we detected caused size reductions, consistent with evolution by natural selection but not with drift. QTL polarities for melanophore number were mixed, however, consistent with genetic drift. Arguments against a role for selection in the regression of cave-fish eyes cited the insignificant cost of their development [2, 3], but we argue that the energetic cost of their maintenance is sufficiently high for eyes to be detrimental in the cave environment. Regression can be caused either by selection or drift.

  12. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  13. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  14. Cryogenic foil bearing turbopumps

    NASA Technical Reports Server (NTRS)

    Gu, Alston L.

    1993-01-01

    Cryogenic foil bearing turbopumps offer high reliability and low cost. The fundamental cryogenic foil bearing technology has been validated in both liquid hydrogen and liquid oxygen. High load capacity, excellent rotor dynamics, and negligible bearing wear after over 100 starts and stops, and over many hours of testing, were observed in both fluids. An experimental liquid hydrogen foil bearing turbopump was also successfully demonstrated. The results indicate excellent stability, high reliability, wide throttle-ability, low bearing cooling flow, and two-phase bearing operability. A liquid oxygen foil bearing turbopump has been built and is being tested at NASA MSFC.

  15. Introduction to ball bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    The purpose of a ball bearing is to provide a relative positioning and rotational freedom while transmitting a load between two structures, usually a shaft and a housing. For high rotational speeds (e.g., in gyroscope ball bearings) the purpose can be expanded to include rotational freedom with practically no wear in the bearing. This condition can be achieved by separating the bearing parts with a coherent film of fluid known as an elastohydrodynamic film. This film can be maintained not only when the bearing carries the load on a shaft, but also when the bearing is preloaded to position the shaft to within micro- or nano-inch accuracy and stability. Background information on ball bearings is provided, different types of ball bearings and their geometry and kinematics are defined, bearing materials, manufacturing processes, and separators are discussed. It is assumed, for the purposes of analysis, that the bearing carries no load.

  16. Morphometry and distribution of isolated caves as a guide for phreatic and confined paleohydrological conditions

    NASA Astrophysics Data System (ADS)

    Frumkin, Amos; Fischhendler, Itay

    2005-04-01

    Isolated caves are a special cave type common in most karst terrains, formed by prolonged slow water flow where aggressivity is locally boosted. The morphometry and distribution of isolated caves are used here to reconstruct the paleohydrology of a karstic mountain range. Within a homogenous karstic rock sequence, two main types of isolated caves are distinguished, and each is associated with a special hydrogeologic setting: maze caves form by rising water in the confined zone of the aquifer, under the Mt. Scopus Group (Israel) confinement, while chamber caves are formed in phreatic conditions, apparently by lateral flow mixing with a vadose input from above.

  17. Comparison between cimetidine and Caved-S in the treatment of gastric ulceration, and subsequent maintenance therapy.

    PubMed Central

    Morgan, A G; McAdam, W A; Pacsoo, C; Darnborough, A

    1982-01-01

    One hundred patients with benign gastric ulceration were treated in a single-blind, endoscopically controlled trial to assess the relative efficacy of cimetidine (1 g daily) and Caved-S (six tablets daily). Ulcer healing was assessed after six weeks' treatment, and, if incomplete, after a further six weeks. There was no significant difference between the two drug regimens (approximately 63% at six weeks and 91% at 12 weeks). If an ulcer remains unhealed after 10 weeks' treatment the patient should undergo surgery. There was no difference in the relief of day pain between the two drug regimens but cimetidine was more effective over the first two weeks of treatment relieving night pain, than was Caved-S (p less than 0 . 02). After ulcer healing, drug dosage was reduced (cimetidine to 400 mg at night and Caved-S to two tablets twice daily). So far, 56 patients, 28 in each group, have completed the first year's maintenance treatment, and there have been four ulcer recurrences in each group (14%). PMID:7042486

  18. Study of radiocarbon dynamics of Baradla Cave, Hungary

    NASA Astrophysics Data System (ADS)

    Molnár, Mihály; Dezsö, Zoltán; Futo, Istvan; Siklósy, Zoltan; Jull, A. J. Timothy; Koltai, Gabriella

    2016-04-01

    Carbon isotope composition of speleothems and their parent drip water reflects the isotope composition of the atmospheric CO2, the soil and the host rock and can sometimes be influenced even by the cave atmosphere. Owing to the fact that 14C in the bedrock has long decayed, the bedrock derived carbon content of the seepage water can be considered as inactive or "dead carbon". The initial dead carbon proportion (dcp) of a stalagmite or tufa layer, caused by the incorporation of the inactive carbon, can be calculated with the help of the C-14 level differences between the contemporary atmosphere and the formed stone carbonate. The revolutionary technological advances of 14C (AMS) have brought the possibility of analysing 14C dynamics of karst systems due to the small amount of demanded material. The Baradla-Domica Cave is the largest cave of Gömör-Torna Karst, a karst area situated in the northeast of Hungary, and located on the Slovakian-Hungarian borderland. The approximately 26 km long cave is a typical example of multi-level speleogenesis. As a case study we have investigated several recent (age < 50 years) and older (age about 10-11 kyrs) stalagmites and recent drip water, some freshwater tufa samples and the recent cave air carbon-dioxide of the Baradla-cave to study the carbon dynamics and dead carbon level there. According four modern stalagmites (formed 1991-2004) the current dcp is very small in Baradla Cave (3-7%). Stalagmites deposited in Holocene (U/Th dated) were also characterized by very small dead carbon contents (1-11% dcp). Outside the cave a dpc about 20-25% was found in a freshwater tufa sample. This relatively low dead carbon content might be either explained by the thinness of the limestone bedrock above (56-80 m) or the relatively fast infiltration conditions, or their combined effect. Cave air is enriched in CO2 (2-5 times higher than in natural air, not homogenous) but the source of this surplus CO2 is not the limestone according its

  19. 46 CFR 67.265 - Requirements for instruments evidencing satisfaction or release.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Requirements for instruments evidencing satisfaction or... for instruments evidencing satisfaction or release. An instrument satisfying or releasing a mortgage... claim of lien is recorded. If the recording information cannot be provided because the satisfaction...

  20. 46 CFR 67.265 - Requirements for instruments evidencing satisfaction or release.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Requirements for instruments evidencing satisfaction or... for instruments evidencing satisfaction or release. An instrument satisfying or releasing a mortgage... claim of lien is recorded. If the recording information cannot be provided because the satisfaction...

  1. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... security or overwhelm Web sites to more traditional intelligence gathering and social engineering aimed at... 39 Postal Service 1 2013-07-01 2013-07-01 false Reporting Postage Evidencing System security... security weaknesses. (a) For purposes of this section, provider refers to the Postage Evidencing...

  2. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... security or overwhelm Web sites to more traditional intelligence gathering and social engineering aimed at... 39 Postal Service 1 2014-07-01 2014-07-01 false Reporting Postage Evidencing System security... security weaknesses. (a) For purposes of this section, provider refers to the Postage Evidencing...

  3. 39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... security or overwhelm Web sites to more traditional intelligence gathering and social engineering aimed at... 39 Postal Service 1 2012-07-01 2012-07-01 false Reporting Postage Evidencing System security... security weaknesses. (a) For purposes of this section, provider refers to the Postage Evidencing...

  4. Morphology and evolution of sulphuric acid caves in South Italy

    NASA Astrophysics Data System (ADS)

    D'Angeli, Ilenia M.; De Waele, Jo; Galdenzi, Sandro; Madonia, Giuliana; Parise, Mario; Vattano, Marco

    2016-04-01

    Sulphuric acid speleogenesis (SAS) related to the upwelling of acid water enriched in H2S and CO2 represents an unusual way of cave development. Since meteoric infiltration waters are not necessarily involved in speleogenesis, caves can form without the typical associated karst expressions (i.e. dolines) at the surface. The main mechanism of sulphuric acid dissolution is the oxidation of H2S (Jones et al., 2015) which can be amplified by bacterial mediation (Engel et al., 2004). In these conditions, carbonate dissolution associated with gypsum replacement, is generally believed to be faster than the normal epigenic one (De Waele et al., 2016). In Italy several SAS caves have been identified, but only few systems have been studied in detail: Frasassi and Acquasanta Terme (Marche)(Galdenzi et al., 2010), Monte Cucco (Umbria) (Galdenzi & Menichetti, 1995), and Montecchio (Tuscany) (Piccini et al., 2015). Other preliminary studies have been carried out in Calabria (Galdenzi, 2007) and Sicily (De Waele et al., 2016). Several less studied SAS cave systems located in South Italy, and in particular in Apulia (Santa Cesarea Terme), Sicily (Acqua Fitusa, Acqua Mintina) and Calabria (Mt. Sellaro and Cassano allo Ionio) have been selected in the framework of a PhD thesis on SAS caves and their speleogenesis. Using both limestone tablet weight loss (Galdenzi et al., 2012) and micro erosion meter (MEM) (Furlani et al., 2010) methods the dissolution rate above and under water in the caves will be quantified. Geomorphological observations, landscape analysis using GIS tools, and the analysis of gypsum and other secondary minerals (alunite and jarosite) (stable isotopes and dating) will help to reconstruct the speleogenetic stages of cave formation. Preliminary microbiological analysis will determine the microbial diversity and ecology in the biofilms. References Engel S.A., Stern L.A., Bennett P.C., 2004 - Microbial contributions to cave formation: New insight into sulfuric acid

  5. Internal cave gating for protection of colonies of the endangered gray bat (Myotis grisescens)

    USGS Publications Warehouse

    Martin, K.W.; Leslie, David M.; Payton, M.E.; Puckette, William L.; Hensley, S.L.

    2003-01-01

    Persistent human disturbance is a major cause for the decline in populations of many cave-dwelling bats and other sensitive cave-obligate organisms. Cave gating has been used to climinate human disturbance, but few studies have assessed directly the impact of such management activities on resident bats. In northeastern Oklahoma, USA, 25 entrances of caves inhabited by two endangered species and one endangered subspecies of bats are protected from human entry with internal gates. Because cave gates may impede ingress and egress of bats at caves, we evaluated the impacts of internal gates before and after their construction at six colonies of endangered gray bats (Myotis grisescens) from 1981 to 2001. No caves were abandoned by gray bats after the construction of internal gates; in fact, total numbers of gray bats using the six caves increased from 60,130 in 1981 to 70,640 in 2001. Two caves harbored more gray bats after gating, and three caves had no change in gray bat numbers after gating. We also compared initiations of emergences at three gated and three open-passage caves in June and July 1999-2000. No differences in timing of initiation of emergence were found between colonies in gated versus open-passage caves. Our results support the use of internal gates to protect and thereby enhance recovery of colonies of endangered gray bats. Additional research is encouraged to confirm that our observations on gray bats are generally applicable to other species of cave-dwelling bats.

  6. Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

    NASA Astrophysics Data System (ADS)

    Yang, S.; Shi, Y.

    2015-10-01

    Ice caves exist in locations where annual average air temperature is higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively investigate the mechanism of formation and preservation of the ice cave, we use the finite-element method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, colored lights, climatic conditions, etc. for sustainable development of the ice cave as a tourism resource. In some other ice caves in China, managers have installed airtight doors at these ice caves' entrances with the intention of "protecting" these caves, but this in fact prevents cooling in winter and these cave ices will entirely melt within tens of years.

  7. Flow Classification and Cave Discharge Characteristics in Unsaturated Karst Formation

    NASA Astrophysics Data System (ADS)

    Mariethoz, G.; Mahmud, K.; Baker, A.; Treble, P. C.

    2015-12-01

    In this study we utilize the spatial array of automated cave drip monitoring in two large chambers of the Golgotha Cave, SW Australia, developed in Quaternary aeolianite (dune limestone), with the aim of understanding infiltration water movement via the relationships between infiltration, stalactite morphology and groundwater recharge. Mahmud et al. (2015) used the Terrestrial LiDAR measurements to analyze stalactite morphology and to characterize possible flow locations in this cave. Here we identify the stalactites feeding the drip loggers and classify each as matrix (soda straw or icicle), fracture or combined-flow. These morphology-based classifications are compared with flow characteristics from the drip logger time series and the discharge from each stalactite is calculated. The total estimated discharge from each area is compared with infiltration estimates to better understand flow from the surface to the cave ceilings of the studied areas. The drip discharge data agrees with the morphology-based flow classification in terms of flow and geometrical characteristics of cave ceiling stalactites. No significant relationships were observed between the drip logger discharge, skewness and coefficient of variation with overburden thickness, due to the possibility of potential vadose-zone storage volume and increasing complexity of the karst architecture. However, these properties can be used to characterize different flow categories. A correlation matrix demonstrates that similar flow categories are positively correlated, implying significant influence of spatial distribution. The infiltration water comes from a larger surface area, suggesting that infiltration is being focused to the studied ceiling areas of each chamber. Most of the ceiling in the cave site is dry, suggesting the possibility of capillary effects with water moving around the cave rather than passing through it. Reference:Mahmud et al. (2015), Terrestrial Lidar Survey and Morphological Analysis to

  8. Radon in Ingleborough / Clapham Cave, North Yorkshire, UK.

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin

    2015-04-01

    Atmospheric radon concentration was measured at Ingleborough Cave, North Yorkshire during the summer of 2004, and the autumn / winter of 2004/5. Significantly, Ingleborough Cave forms part of a larger system which includes the world famous Gaping Gill pothole. This plunges 105 m (334 ft), contains the tallest unbroken waterfall in England and one of the largest known underground chambers in the UK. Measurements were taken to assess the effects of seasonal and spatial variation, elevation and ventilation on radon concentration in Ingleborough. In this study personal dose exposures for three groups of cave user were identified, and the performance of a variety of radon detection systems evaluated. Summer radon concentrations inside the cave peaked at around 7,000 Bq m-3, although average concentrations were less than 5,000 Bq m-3. During the winter measurement period, average concentrations were around 100 Bq m-3, and a winter / summer ration therefore of 47,4. The average annual radon concentration exceeded the legislative limitations for the workplace of 400 Bq m-3 due in part to a failed fan in the ventilation system. When the fan was running we noted an 80% reduction in radon concentrations although reliability of the fan was problematic due to extensive but relatively rare flooding of the cave system. The radon dose experienced by cave workers and guides in this study exceeded the Ionisation Radiation Regulations limit of 5 mSv/annum, and highlighted that for health and safety reasons the ventilation system should be fully operational during the high radon concentration summer months. Keywords: Radon, Cave, Ingleborough, Detection methods

  9. Paleo-watertable definition using cave ferromanganese stromatolites and associated cave-wall notches (Sierra de Arnero, Spain)

    NASA Astrophysics Data System (ADS)

    Rossi, Carlos; Villalaín, Juan J.; Lozano, Rafael P.; Hellstrom, John

    2016-05-01

    The steeply-dipping-dolostone-hosted caves of the Sierra de Arnero (N Spain) contain low-gradient relict canyons with up to ten mapped levels of ferromanganese stromatolites and associated wall notches over a vertical range of 85 m, the highest occurring ~ 460 m above base level. Despite a plausible speleogenetic contribution by pyrite oxidation, and the irregular cave-wall mesomorphologies suggestive of hypogenic speleogenesis, the Arnero relict caves are dominantly epigenic, as indicated by the conduit pattern and the abundant allogenic sediments. Allogenic input declined over time due to a piracy-related decrease in the drainage area of allogenic streams, explaining the large size of the relict Arnero caves relative to the limited present-day outcrop area of the karstified carbonates. Allogenic-sediment input also explains the observed change from watertable canyons to phreatic conduits in the paleo-downstream direction. Stromatolites and notches arguably formed in cave-stream passages at the watertable. The best-defined paleo-watertables show an overall slope of 1.7°, consistent with the present-day relief of the watertable, with higher-slope segments caused by barriers related to sulfide mineralization. The formation of watertable stromatolites favored wall notching by the combined effect of enhanced acidity by Mn-Fe oxidation and shielding of cave floors against erosion. Abrasive bedload further contributed to notch formation by promoting lateral mechanical erosion and protecting passage floors. The irregular wallrock erosional forms of Arnero caves are related partly to paragenesis and partly to the porous nature of the host dolostones, which favored irregular dissolution near passage walls, generating friable halos. Subsequent mechanical erosion contributed to generate spongework patterns. The dolostone porosity also contributes to explain the paradox that virtually all Arnero caves are developed in dolostone despite being less soluble than adjacent

  10. Pleistocene cave art from Sulawesi, Indonesia.

    PubMed

    Aubert, M; Brumm, A; Ramli, M; Sutikna, T; Saptomo, E W; Hakim, B; Morwood, M J; van den Bergh, G D; Kinsley, L; Dosseto, A

    2014-10-09

    Archaeologists have long been puzzled by the appearance in Europe ∼40-35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces) and portable art (for example, carved figurines), and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia, where modern humans (Homo sapiens) were established by 50 kyr ago. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa ('pig-deer') made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ∼40 kyr ago at opposite ends of the Pleistocene Eurasian world.

  11. A prototype mass spectrometer for in situ analysis of cave atmospheres

    NASA Astrophysics Data System (ADS)

    Patrick, Edward L.; Mandt, Kathleen E.; Mitchell, Evelynn J.; Mitchell, Joseph N.; Younkin, Kerri N.; Seifert, Clarissa M.; Williams, Gregg C.

    2012-10-01

    Research in cave environments has many applications: studying local hydrogeologic activity, paleoclimate studies, analyzing white nose syndrome in bat populations, analogs for underground atmospheres in mining facilities, carbon sequestration efforts, and terrestrial analogs for planetary caves. The atmospheres of many caves contain tracers of current geological and biological activity, but up to this point, in situ studies have been limited to sensors that monitor individual components of the cave atmosphere. A prototype cave mass spectrometer system was assembled from commercial off-the-shelf parts to conduct surveys of atmospheric compositions inside four local Texas caves and to perform atmospheric analysis of two aquifer wellheads to a depth of 60 m. We found increased levels of CO2 in all caves and, surprisingly, increased levels of O2 in Bracken Bat Cave. Aquifer wellhead measurements showed indications of methane, other hydrocarbons, and other constituents not anticipated.

  12. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the public, including those who utilize caves for scientific, educational, and recreational purposes, the opportunity to nominate potential significant caves. The authorized officer will give public...) Paleontologic resources with potential to contribute useful educational and scientific information....

  13. Field test of a calcite dissolution rate law: Fort's Funnel Cave, Mammoth Cave National Park

    SciTech Connect

    Slunder, J.S. ); Groves, C.G. . Center for Cave and Karst Studies)

    1994-03-01

    The laboratory-derived calcite dissolution rate law of Plummer et al. (1978) is the most widely used and mechanistically detailed expression currently available for predicting dissolution rates as a function of water chemistry. Such rate expressions are of great use in understanding timescales associated with limestone karst development. Little work has gone into the field testing of the rate law under natural conditions. This work measured dissolution rates by a crystal weight loss experiment in Buffalo Creek within Fort's funnel Cave, which lies within a pristine, forested catchment of Mammoth Cave National Park. Continuous water chemistry sampling over the same period allowed a time-integrated prediction of the dissolution based on the Plummer et al. (1978) expression. Results indicate that the rate law overpredicted dissolution by a factor of about ten. This concurs with earlier laboratory work suggesting that the law tends to overpredict rates in solutions close to equilibrium with respect to calcite, as were the waters within this part of the groundwater flow system.

  14. Tamarugite from Diana Cave (SW Romania) -first true karst occurrence

    NASA Astrophysics Data System (ADS)

    Pušcaš, C. M.; Onac, B. P.; Effenberger, H. S.; Povarǎ, I.

    2012-04-01

    Diana Cave is located within the town limits of Baile Herculane (SW Romania) and develops as a 14 m long, westward oriented, unique passage guided by the Diana fault [1]. At the far end of the cave, the thermo-mineral Diana Spring wells forth. In the early 1970s a mine gallery that intersected the cave was created to drain the water into a pumping station and the original cave passage was somewhat altered and reinforced with concrete. Today the concrete and the silty limestone cave walls are heavily corroded by H2SO4 outgassing from the hot water (ca. 50°C) and display abundant gypsum crusts, soggy aggregates of native S, and a variety of more exotic sulfates. Among them, a mineral that has been previously identified in caves only in connection to volcanic activity, either as thermal springs or fumaroles [2]: tamarugite [NaAl(SO4)26H2O]. It was [3] that first mentioned the occurrence of this Na and Al sulfate in Diana Cave, our research aiming to give a detailed description of this mineral, its paragenesis, and mechanisms of precipitation. Recently, tamarugite has also been identified in a sulfuric acid cave from Greece [4]. Along with powder X-ray diffractions coupled with Rietveld refinement, scanning electron microscope, and electron probe micro-analysis, δ18O and δ34S compositions of the sulfate mineral as well as precipitates from the water were analyzed to identify and better constrain the genesis of this rare sulfate. Regrettably, the crystal size of our specimens is inappropriate for identification by means of single crystal X-ray diffraction. Physical and chemical parameters of Diana Spring were as well measured on several occasions. Geochemical analysis suggests that the minute, white tamarugite flakes precipitated in Diana Cave as a result of the interactions between the thermo-mineral water or water vapor and the original limestone bedrock and concrete that blankets the mine gallery. [1] Povara, I., Diaconu, G., Goran, C. (1972). Observations pr

  15. Geomicrobiology of Phreatic Caves Associated With Central Florida Springs

    NASA Astrophysics Data System (ADS)

    Giannotti, A. L.; Tysall, T. N.; Franklin, R. B.; Mills, A. L.

    2005-05-01

    Phreatic (underwater) limestone caves are common in Florida in association with the numerous springs that issue from the karst landscape. Extensive microbial mats and diverse communities of invertebrates have been observed by cave divers, but, as ecosystems, the caves are not well studied. Four aphotic aquatic caves were identified in which to investigate relationships between microbial communities and their geochemical surroundings, and to evaluate the potential for chemolithoautotrophic microbial activity to support higher-order consumers. The caves were associated with the discharge sites of four different second-magnitude springs (flow: 0.3 to 3 m3 s-1) in central Florida in which communities containing microbial mats, isopods, amphiphods, and cave crayfish have been observed. Samples of bulk water and microbial mat were collected along the flow path in each cave; depths ranged from 0.5 to 15 m below the ground surface, and penetration distance extended up to 250 m from each cave entrance. Microscopic examination of the mats revealed the presence of sulfur-granule-containing, filamentous morphologies consistent with Thiothrix and Beggiatoa and an unidentified filamentous iron bacteria. The bacteria were found in all four springs, but H2S was detected in water samples from only one of the caves. In many cases, the morphology of the organisms changed along the flow path within an individual spring, although there was little change in the associated water chemistry (pH, dissolved oxygen, conductivity, total Fe, NH4+, NO3-, HS-, SO42-, PO4-, Cl-, Fl-, Ca2+, Na+, and Mg2+). The overall water chemistry of the four caves/springs was distinct (principal components analysis), and the major differences were due to Ca2+, K+, and Cl- concentrations, pH (range: 7.3 to 8.4), and sulfur and iron availability. Efforts to culture the dominant organisms in each set of mats (using media prepared with cave or spring water) and community-level genetic analyses (T-RFLP) demonstrated

  16. The CAVE (TM) automatic virtual environment: Characteristics and applications

    NASA Technical Reports Server (NTRS)

    Kenyon, Robert V.

    1995-01-01

    Virtual reality may best be defined as the wide-field presentation of computer-generated, multi-sensory information that tracks a user in real time. In addition to the more well-known modes of virtual reality -- head-mounted displays and boom-mounted displays -- the Electronic Visualization Laboratory at the University of Illinois at Chicago recently introduced a third mode: a room constructed from large screens on which the graphics are projected on to three walls and the floor. The CAVE is a multi-person, room sized, high resolution, 3D video and audio environment. Graphics are rear projected in stereo onto three walls and the floor, and viewed with stereo glasses. As a viewer wearing a location sensor moves within its display boundaries, the correct perspective and stereo projections of the environment are updated, and the image moves with and surrounds the viewer. The other viewers in the CAVE are like passengers in a bus, along for the ride. 'CAVE,' the name selected for the virtual reality theater, is both a recursive acronym (Cave Automatic Virtual Environment) and a reference to 'The Simile of the Cave' found in Plato's 'Republic,' in which the philosopher explores the ideas of perception, reality, and illusion. Plato used the analogy of a person facing the back of a cave alive with shadows that are his/her only basis for ideas of what real objects are. Rather than having evolved from video games or flight simulation, the CAVE has its motivation rooted in scientific visualization and the SIGGRAPH 92 Showcase effort. The CAVE was designed to be a useful tool for scientific visualization. The Showcase event was an experiment; the Showcase chair and committee advocated an environment for computational scientists to interactively present their research at a major professional conference in a one-to-many format on high-end workstations attached to large projection screens. The CAVE was developed as a 'virtual reality theater' with scientific content and

  17. Investigating Science through Bears (and Teddy Bears).

    ERIC Educational Resources Information Center

    Smith, Karlene Ray

    1997-01-01

    Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear…

  18. The setting of the Mt. Carmel caves reassessed

    NASA Astrophysics Data System (ADS)

    Vita-Finzi, Claudio; Stringer, Chris

    2007-02-01

    Four caves on the SW flank of Mt. Carmel, es Skhul, el Wad, el Jaml and et Tabun, were first excavated in the 1930s by a team led by Dorothy Garrod. They yielded human remains whose age and evolutionary status remain controversial partly because the complexity of the cave deposits invites conflicting interpretations. The abrasion of artefacts and pebbles in el Wad and es Skhul, which was originally ascribed to spring flow within the caves, is explained here by wave action, with the implication that during part of the Middle Palaeolithic the caves were on the shoreline rather than being separated from it—as they now are—by several kilometres of coastal plain and a height difference of some 45 m. U-series, thermoluminescence (TL) and electron spin resonance (ESR) dating suggests that this occurred about 120,000 years ago, when sea level in the eastern Mediterranean stood 5-6 m above its present position. It follows that Mt. Carmel has subsequently undergone some 40 m of uplift. During the period of maximum submergence, the coastal route between Africa and the northern Mediterranean would have been partly blocked, but the loss of the coastal plain for transit and as a source of animal food was offset by easier access from the caves to marine resources.

  19. Mining safety of longwall top-coal caving in China

    SciTech Connect

    Wu, J.; Qin, Y.; Zhai, M.

    1999-07-01

    Longwall top-coal caving technology has developed rapidly in China, in recent years. The application of longwall top-coal caving can double both the productivity and the efficiency of a working face and reduce the cost of production by 30 to 50%. Using standard longwall equipment, annual production can reach 3 million metric tons (Mt), and a maximum of 4.1 Mt has been obtained; many top-coal caving longwall working faces can obtain 200 tons per man-shift. Longwall top-coal caving is distinctly different from slice mining in thicken seam. Concerns of safety and productivity for this method have been raised in recent years. This paper will discuss the following: (1) how to recognize the law of fire-damp emission, accumulation and outburst; (2) how to resolve the ventilation problem in a highly gassy working face; (3) how to recognize the law of spontaneous combustion of ignitable coal, and to avoid spontaneous combustion in gob area; and (4) how to control dust in longwall top-coal caving face.

  20. Sandstone caves on Venezuelan tepuis: Return to pseudokarst?

    NASA Astrophysics Data System (ADS)

    Aubrecht, R.; Lánczos, T.; Gregor, M.; Schlögl, J.; Šmída, B.; Liščák, P.; Brewer-Carías, Ch.; Vlček, L.

    2011-09-01

    Venezuelan table mountains (tepuis) host the largest arenite caves in the world. The most frequently used explanation of their origin so far was the "arenization" theory, involving dissolution of quartz cement around the sand grains and subsequent removing of the released grains by water. New research in the two largest arenite cave systems - Churi-Tepui System in Chimanta Massif and Ojos de Cristal System in Roraima Tepui showed that quartz dissolution plays only a minor role in their speleogenesis. Arenites forming the tepuis are not only quartzites but they display a wide range of lithification and breakdown, including also loose sands and sandstones. Speleogenetic processes are mostly concentrated on the beds of unlithified sands which escaped from diagenesis by being sealed by the surrounding perfectly lithified quartzites. Only the so-called "finger-flow" pillars testify to confined diagenetic fluids which flowed in narrow channels, leaving the surrounding arenite uncemented. Another factor which influenced the cave-forming processes by about 30% was lateritization. It affects beds formed of arkosic sandstones and greywackes which show strong dissolution of micas, feldspars and clay minerals, turning then to laterite ("Barro Rojo"). The main prerequisite to rank caves among karst phenomena is dissolution. As the dissolution of silicate minerals other than quartz appears to play not only a volumetrically important role but even a trigger role, these arenitic caves may be ranked as karst.

  1. Mechanical spin bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1998-01-01

    A spin bearing assembly including, a pair of mutually opposing complementary bearing support members having mutually spaced apart bearing support surfaces which may be, for example, bearing races and a set of spin bearings located therebetween. Each spin bearing includes a pair of end faces, a central rotational axis passing through the end faces, a waist region substantially mid-way between the end faces and having a first thickness dimension, and discrete side surface regions located between the waist region and the end faces and having a second thickness dimension different from the first thickness dimension of the waist region and wherein the side surface regions further have respective curvilinear contact surfaces adapted to provide a plurality of bearing contact points on the bearing support members.

  2. A Framework for Aligning Instructional Design Strategies with Affordances of CAVE Immersive Virtual Reality Systems

    ERIC Educational Resources Information Center

    Ritz, Leah T.; Buss, Alan R.

    2016-01-01

    Increasing availability of immersive virtual reality (IVR) systems, such as the Cave Automatic Virtual Environment (CAVE) and head-mounted displays, for use in education contexts is providing new opportunities and challenges for instructional designers. By highlighting the affordances of IVR specific to the CAVE, the authors emphasize the…

  3. Project C.A.V.E.S.: High School Spelunking in Arkansas.

    ERIC Educational Resources Information Center

    Reese, Rachel

    1989-01-01

    Project CAVES (Creative Adventures and Valuable Experiences through Spelunking) is a summer residential program for gifted high-school students, involving lectures, surveying and mapping simulated caves, and exploring and surveying actual caves in Arkansas. The project's development and learning activities are described. (JDD)

  4. Identifying Source Mixing and Examining Water Chemistry Variations: The Carroll Cave - Toronto Springs System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Located in the Missouri Ozarks, Carroll Cave is a dendritic stream cave system, formed in Ordivician Gasconade dolomite. In 2002, a new survey effort was launched under the auspices of the Carroll Cave Conservancy to provide a comprehensive map of the system. Since that time, 29.89 km of estimated p...

  5. Fossil invertebrates records in cave sediments and paleoenvironmental assessments - a study of four cave sites from Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2016-01-01

    Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new to science, and most of them are indicative for either warm and/or cold stages or dry and/or wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures and hydraulic regimes could be gathered. This paper analyzes the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  6. Axial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2008-01-01

    Axial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control.

  7. New Species of Campodeidae (Diplura) from Mexican caves.

    PubMed

    Sendra, Alberto; Palacios, Jose; Garcia, Arturo; Montejo, Maira

    2016-02-04

    Six new taxa of Campodeidae (Diplura) are described in the genera Litocampa, Juxtlacampa, Oncinocampa, and Tachycampa. We also redescribe the interesting species Juxtlacampa juxtlahucensis Wygodzinsky, 1944 from Juxtlahuaca cave in Guerrero, Mexico. All of these taxa are cave-dwelling species with more or less noticeable troglobiomorphic features They inhabit the subterranean ecosystem in six limestone massifs and one lava tube cave in the central states of Mexico. Four of these species are included in the "tachycampoide" group and one species in the "podocampoide" group (sensu Bareth & Conde). Nine species already known in Central and South America of the "tachycampoide" group, in such poorly-sampled regions compared with the eight species in the well-sampled Mediterranean region (Ibero-Sardinia and north Africa), suggest an American origin for this group.

  8. Molecular Characterization of Aquatic Bacterial Communities in Dinaric Range Caves.

    PubMed

    Pleše, Bruna; Pojskić, Naris; Ozimec, Roman; Mazija, Mirna; Ćetković, Helena; Lukić-Bilela, Lada

    2016-07-01

    Dinaric limestone cave systems, recognized as a hotspot of subterranean biodiversity, inhabit composite microbial communities whose structure, function and importance to ecosystems was poorly considered until the last few years. Filamentous microbial biofilms from three caves in Dinaric karst were assessed using 16S rRNA-based phylogenetic approach combined with universally protein coding genes/proteins. Studied clone libraries shared divisions but phylogenetic distribution of the obtained phylotypes differed: in Veternica and Vjetrenica clone libraries, Nitrospirae prevailed with 36% and 60% respectively, while in Izvor Bistrac the most abundant were Alphaproteobacteria (41%) followed by Firmicutes (32%). Moreover, three phylotypes were associated with novel uncultured candidate divisions OP3, WS5 and OD1 revealing the diversity and uniqueness of the microbial world in caves. Deeply understanding subterranean habitats could elucidate many new aspects in phylogeny and evolution of microorganisms as well as animal taxa, adjacent to their energy suppliers in microbial communities and biofilms.

  9. Late Pleistocene human remains from Wezmeh Cave, western Iran.

    PubMed

    Trinkaus, Erik; Biglari, Fereidoun; Mashkour, Marjan; Monchot, Hervé; Reyss, Jean-Louis; Rougier, Hélène; Heydari, Saman; Abdi, Kamyar

    2008-04-01

    Paleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P(3) or possibly P(4)). Species representation and U-series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P(3) and P(4) dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore-dominated cave assemblages.

  10. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  11. Radon and thoron in cave dwellings (Yan'an, China)

    SciTech Connect

    Wiegand, J.; Feige, S.; Xie Quingling; Schreiber, U.; Wieditz, K.; Wittmann, C.; Luo Xiarong

    2000-04-01

    {sup 222}Rn and {sup 220}Rn concentrations were measured in cave dwellings and brick houses in the region of Yan'an (China) during summer 1997. The underground dwellings are built into Quaternary loess, and all investigated houses are founded on it. The median values of indoor {sup 222}Rn and {sup 220}Rn concentrations are 42 (n = 18) and 77Bq m{sup {minus}3} (n = 15) for brick houses and 92 (n = 23) and 215 (n = 17) Bq m{sup {minus}3} for cave dwellings. To classify the dwellings in respect to their cave-character, the fraction of walls having a direct contact to the loess is calculated for each dwelling. While the {sup 222}Rn concentrations are increasing with higher fractions, the {sup 220}Rn concentrations are not correlated with this fraction. On the other hand, due to the short half-life of {sup 220}Rn the distance from the measuring point to the walls is negatively correlated with the {sup 220}Rn concentration, while there is no correlation with the {sup 222}Rn concentration. Therefore, concentric isolines of {sup 220}Rn concentrations showing a strong gradient were detected in cave dwellings. An influence of the ventilation rate is distinct for {sup 222}Rn but weak for {sup 220}Rn. The effective dose rates for {sup 222}Rn and {sup 220}Rn and their progenies are calculated for brick houses (2.7 mSv y{sup {minus}1}), cave dwellings (7.1 mSv y{sup {minus}1}), and for traditional cave dwellings with a bed foundation built with loess (16.7 mSv y{sup {minus}1}). These calculations are based on summer measurements only. It is expected that the true effective dose rates will be significantly higher.

  12. Vermiculation patterns in Coiba Mare cave, Bihor Mountains, Romania

    NASA Astrophysics Data System (ADS)

    Bojar, Ana-Voica; Guja, Ovidiu; Stefanescu, Daniel

    2014-05-01

    Vermiculation patterns developing on cave surfaces are certainly a spectacular feature. Sometimes vermiculation cover hundreds of square meters, like for example in Coiba Mare cave, which is situated in the Bihor Mountains, Romania. The Coiba Mare Cave is located at 1020 m altitude, on the Gardisoara Valley, not far from the Casa de Piatra Hamlet, in the Apuseni Natural Park (Bihor Mountains) situated in the western part of Romania. The first written document concerning the cave dates back to 1929, when R. Jeannel and E. Racovitza presented a brief description. Speleological investigations, which were started by I. Viehmann, D. Coman and M. Bleahu in 1953, were continued by several speleological clubs during 1975-1976. In this study, we are investigating the mineralogy, stable isotope distribution and patterns of vermiculations in the Coiba Mare cave. Material from the vermiculations developed on cave wall was analysed using Powder X-ray diffraction (PXRD), Fourier transformed infrared (FTIR) and energy dispersive analyses (EDS). The material consists mainly of calcite with traces of quartz, muscovite, chlinochlore, kaolinite, potassium feldspar and organic material. In Coiba Mare, the general look of the vermiculation pattern is that of a "pelli de leopardo" (Leopard's spots), a term used by Bini et al. (1978) for large vermiculations composed of clay. In the light of previous literature and according, to the own field and laboratory data a mechanism responsible for the formation of vermiculations is proposed. Evaporation and water film rupture cause the concentration of the loose particles. Evaporation is also associated with the formation of calcite microcrystals at the water-air interface. Concentration of the particle in vermiculations patterns and crystallisation is the result of evaporation and shrinking water spots.

  13. Assemblages of Desire: Infants, Bear Caves and Belonging in Early Childhood Education and Care

    ERIC Educational Resources Information Center

    Stratigos, Tina

    2015-01-01

    Belonging is emerging as an important concept in contemporary early childhood curricula, and calls have recently been made for belonging to be critically interrogated and further theorized. This article explores how belonging was operating for an infant in Australian family day care by looking at an episode that took place between the infant, a…

  14. Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis

    SciTech Connect

    Lauf, R.J.

    1997-07-01

    Microcrystals of secondary sulfate minerals from Alum Cave Bluff, Great Smoky Mountains National Park, were examined by scanning electron microscopy and identified by X-ray fluorescence (XRF) in the SEM. Among the samples the author discovered three new rare-earth sulfates: coskrenite-(Ce), levinsonite-(Y), and zugshunstite-(Ce). Other minerals illustrated in this report include sulfur, tschermigite, gypsum, epsomite, melanterite, halotrichite, apjohnite, jarosite, slavikite, magnesiocopiapite, and diadochite. Additional specimens whose identification is more tentative include pickeringite, aluminite, basaluminite, and botryogen. Alum Cave is a ``Dana locality`` for apjohnite and potash alum, and is the first documented North American occurrence of slavikite.

  15. Rare cause of trigeminal neuralgia: Meckel's cave meningocele.

    PubMed

    Alobaid, Abdullah; Schaeffer, Todd; Virojanapa, Justin; Dehdashti, Amir R

    2015-07-01

    The most common etiology of classic trigeminal neuralgia is vascular compression. However, other causes must be excluded. It is very unlikely that a meningocele presents with symptomatic trigeminal neuralgia. We present a rare case of a patient presenting with left trigeminal neuralgia. Thin-slice CT and MRI showed a transclival Meckel's cave meningocele. The patient underwent endoscopic repair of the meningocele, which resulted in complete resolution of her symptoms. Meckel's cave meningocele or encephalocele should be considered among the differential diagnoses of trigeminal neuralgia. Meningocele repair should be suggested as the first treatment option in this rare situation.

  16. TOPICAL REVIEW: Superconducting bearings

    NASA Astrophysics Data System (ADS)

    Hull, John R.

    2000-02-01

    The physics and technology of superconducting bearings is reviewed. Particular attention is given to the use of high-temperature superconductors (HTSs) in rotating bearings. The basic phenomenology of levitational forces is presented, followed by a brief discussion of the theoretical models that can be used for conceptual understanding and calculations. The merits of various HTS bearing designs are presented, and the behaviour of HTS bearings in typical situations is discussed. The article concludes with a brief survey of various proposed applications for HTS bearings.

  17. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  18. The sources and sinks of CO2 in caves under mixed woodland and grassland vegetation

    NASA Astrophysics Data System (ADS)

    Breecker, Daniel O.; Payne, Ashley E.; Quade, Jay; Banner, Jay L.; Ball, Carolyn E.; Meyer, Kyle W.; Cowan, Brian D.

    2012-11-01

    We measured concentrations and stable carbon isotope compositions of carbon dioxide in the atmospheres of three caves in central Texas and one cave in southern Arizona in order to identify CO2 sources and sinks. The vegetation above the caves studied is either savannah (two caves, above which vegetation has been minimally disturbed) or discrete patches of grassland and woodland (two caves, above which vegetation has been highly disturbed). We tested two hypotheses concerning CO2 in the cave atmospheres: (1) cave ventilation by tropospheric air is the primary sink for CO2 and (2) CO2 is primarily derived from the deepest rooting plants growing above the caves. Within caves, we monitored CO2 at individual locations on monthly and daily time-scales and measured CO2 along transects with increasing distance from the cave entrances. We also measured CO2 in the pore spaces of soils under grasses and trees above each of the caves. We calculated δ13C values of respired CO2 (δ13Cr) for all gas samples using measured δ13C values and CO2 concentrations. We then identified the sources of cave CO2 by comparing cave-air and soil CO2δ13Cr values. At all locations in each Texas cave, CO2 concentrations were highest (lowest) and δ13C values were lowest (highest) during the summer (winter). Cave-air CO2 concentrations consistently increased and δ13C values consistently decreased with distance from the cave entrances. Similar but smaller magnitude seasonal variations in CO2 concentrations occurred in the Arizona cave and no seasonal or spatial variation in the δ13C of cave-air CO2 was observed. The mean δ13Cr values of CO2 in soils under grass were 3.5-4.5‰ higher than the δ13Cr values of CO2 in soils under trees. In the caves under savannah, mean δ13Cr values of cave-air CO2 (-24‰ in both caves) were within 1‰ of the mean δ13Cr values of CO2 in soils under trees. In caves covered by large, contiguous areas of grassland, the δ13Cr values of cave-air CO2 were similar

  19. The first troglobitic Pseudonannolene from Brazilian iron ore caves (Spirostreptida: Pseudonannolenidae).

    PubMed

    Iniesta, Luiz Felipe Moretti; Ferreira, Rodrigo Lopes

    2013-01-01

    Pseudonannolene spelaea n. sp. is the first strictly cave-dwelling species described for the family Pseudonannolenidae. It is found in iron ore caves in the Brazilian Amazon. The family Pseudonannolenidae is exclusively Neotropical and frequently found in caves of Brazil, from which 20 species are known. The new species is compared with its congeners and with related cave-dwelling species. The family Pseudonannolenidae is discussed, and comments are presented on the conservation status of the caves where the species is found, which potentially may be the target of anthropogenic impacts resulting from iron ore extraction.

  20. Bacterial Diversity and Composition in Oylat Cave (Turkey) with Combined Sanger/Pyrosequencing Approach.

    PubMed

    Gulecal-Pektas, Yasemin

    2016-01-01

    The microbiology of caves is an important topic for better understanding subsurface biosphere diversity. The diversity and taxonomic composition of bacterial communities associated with cave walls of the Oylat Cave was studied first time by molecular cloning based on Sanger/pyrosequencing approach. Results showed an average of 1,822 operational taxonomic units per sample. Clones analyzed from Oylat Cave were found to belong to 10 common phyla within the domain Bacteria. Proteobacteria dominated the phyla, followed by Actinobacteria, Acidobacteria and Nitrospirae. Shannon diversity index was between to 3.76 and 5.35. The robust analysis conducted for this study demonstrated high bacterial diversity on cave rock wall surfaces.

  1. Prevention and treatment of injuries from cave exploration in Hawai'i.

    PubMed

    Cowart, David W; Halleck, John B; Park, Benjamin R

    2014-11-01

    Cave exploration is a popular activity in the United States that can be challenging, thrilling, and dangerous. In addition to common risks associated with caves on the mainland, caves in Hawai'i may be filled with tidal water, or contain large pools of water that are accessible only through underwater entrances. This paper will discuss common injuries in caves on the mainland United States, as well as cave related injuries in Hawai'i as reported to the National Speleological Society from 1984-2013.

  2. Speleology and magnetobiostratigraphic chronology of the Buffalo Cave fossil site, Makapansgat, South Africa

    NASA Astrophysics Data System (ADS)

    Herries, Andy I. R.; Reed, Kaye E.; Kuykendall, Kevin L.; Latham, Alf G.

    2006-09-01

    Speleological, stratigraphic, paleomagnetic and faunal data is presented for the Buffalo Cave fossil site in the Limpopo Province of South Africa. Speleothems and clastic deposits were sampled for paleomagnetic and mineral magnetic analysis from the northern part of the site, where stratigraphic relationships could be more easily defined and a magnetostratigraphy could therefore be developed for the site. This is also where excavations recovered the fossil material described. A comparison of the east and South African first and last appearance data with the Buffalo Cave fauna was then used to constrain the magnetostratigraphy to produce a more secure age for the site. The magnetostratigraphy showed a change from normal to reversed polarity in the basal speleothems followed by a short normal polarity period in the base of the clastic deposits and a slow change to reversed directions for the remainder of the sequence. The biochronology suggested an optimal age range of between 1.0 Ma and 600,000 yr based on faunal correlation with eastern and southern Africa. A comparison of the magnetobiostratigraphy with the GPTS suggests that the sequence covers the time period from the Olduvai event between 1.95 and 1.78 Ma, through the Jaramillo event at 1.07 Ma to 990,000 yr, until the Bruhnes-Matuyama boundary at 780,000 yr. The faunal-bearing clastic deposits are thus dated between 1.07 Ma and 780,000 yr with the main faunal remains occurring in sediments dated to just after the end of the Jaramillo Event at 990,000 yr.

  3. Gas discharges in fumarolic ice caves of Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Fischer, T. P.; Curtis, A. G.; Kyle, P. R.; Sano, Y.

    2013-12-01

    Fumarolic ice caves and towers on Erebus are the surface expression of flank degassing on the world's southernmost active volcano. The caves are formed by warm gases and steam escaping from small vents on the lava flow floors that melts the overlying ice and snow. Extremophiles in the caves may be analogues for extraterrestrial environments. Over the past four Austral summers, mapping, gas and thermal monitoring conducted under the Erebus Caves Project has provided insights into the ice cave formation processes and the relationships between cave structures, magmatic processes, and weather. Gas samples were collected during the 2012 - 2013 field season in 4 ice caves (Warren, Harry's Dream, Sauna, Haggis Hole) as well as the thermal ground at Tramway Ridge. The vents at all of these sites are characterized by diffuse degassing through loose lava or cracks in the lava flow floor. Vent temperatures ranged from 5 to 17°C in most caves and at Tramway Ridge. In Sauna cave the temperature was 40°C. Gases were sampled by inserting a perforated 1 m long, 5 mm diameter stainless steel tube, into the vents or hot ground. Giggenbach bottles, copper tubes and lead glass bottles were connected in series. The gases were pumped at a slow rate (about 20 ml per minute) using a battery pump for 12-24 hours to flush the system. After flushing samples were collected for later analyses. All samples are dominated by atmospheric components, however, carbon dioxide (0.1 to 1.9%), methane (0.005 to 0.01%), hydrogen (0.002 to 0.07%), and helium (0.0009 to 0.002 %) are above air background. Nitrogen (average 74%) and oxygen (23.5%) are slightly below and above air values, respectively. Helium isotopes show minor input of mantle derived helium-3 with 3He4He ratios ranging from 1.03 to 1.18 RA (where RA is the ratio of air). This represents the first detection of hydrogen and helium in the caves. Methane could be produced by anaerobic respiration of subsurface microbes or hydrothermal

  4. Luminescence chronology of cave sediments at the Atapuerca paleoanthropological site, Spain.

    PubMed

    Berger, G W; Pérez-González, A; Carbonell, E; Arsuaga, J L; Bermúdez de Castro, J-M; Ku, T-L

    2008-08-01

    Ascertaining the timing of the peopling of Europe, after the first out-of-Africa demographic expansion at the end of the Pliocene, is of great interest to paleoanthropologists. One of the earliest direct evidences for fossil hominins in western Europe comes from an infilled karstic cave site called Gran Dolina at Atapuerca, in a stratum approximately 1.5m below the Brunhes-Matuyama (B-M) geomagnetic boundary (780ka) within lithostratigraphic unit TD6. However, most of the meters of fossil- and tool-bearing strata at Gran Dolina have been difficult to date. Therefore, we applied both thermoluminescence (TL) and infrared-stimulated-luminescence (IRSL) multi-aliquot dating methods to fine-silt fractions from sediment samples within Gran Dolina and the nearby Galería cave site. We also applied these methods to samples from the present-day surface soils on the surrounding limestone hill slopes to test the luminescence-clock-zeroing-by-daylight assumption. Within the uppermost 4m of the cave deposits at Gran Dolina, TL and paired TL and IRSL ages range stratigraphically from 198+/-19ka to 244+/-26ka. Throughout Gran Dolina, all luminescence results are stratigraphically self-consistent and, excepting results from two stratigraphic units, are consistent with prior ESR-U-series ages from progressively deeper strata. Thermoluminescence ages culminate at 960+/-120ka approximately 1m below the 780ka B-M boundary. At Galería, with one exception, TL and IRSL ages range stratigraphically downward from 185+/-26ka to 503+/-95ka at the base of the lowermost surface-inwash facies. These results indicate that TL and (sometimes) IRSL are useful dating tools for karstic inwash sediments older than ca. 100ka, and that a more accurate chronostratigraphic correlation is now possible among the main Atapuerca sites (Gran Dolina, Galería, Sima de los Huesos). Furthermore, the oldest TL age of ca. 960ka from Gran Dolina, consistent with biostratigraphic and paleomagnetic evidence, implies

  5. A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

    PubMed

    Lourenço, Wilson R; Pham, Dinh-Sac

    2014-09-01

    Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

  6. Profiling bacterial diversity in a limestone cave of the western Loess Plateau of China

    PubMed Central

    Wu, Yucheng; Tan, Liangcheng; Liu, Wuxing; Wang, Baozhan; Wang, Jianjun; Cai, Yanjun; Lin, Xiangui

    2015-01-01

    Bacteria and archaea sustain subsurface cave ecosystems by dominating primary production and fueling biogeochemical cyclings, despite the permanent darkness and shortage of nutrients. However, the heterogeneity and underlying mechanism of microbial diversity in caves, in particular those well connect to surface environment are largely unexplored. In this study, we examined the bacterial abundance and composition in Jinjia Cave, a small and shallow limestone cave located on the western Loess Plateau of China, by enumerating and pyrosequencing small subunit rRNA genes. The results clearly reveal the contrasting bacterial community compositions in relation to cave habitat types, i.e., rock wall deposit, aquatic sediment, and sinkhole soil, which are differentially connected to the surface environment. The deposits on the cave walls were dominated by putative cave-specific bacterial lineages within the γ-Proteobacteria or Actinobacteria that are routinely found on cave rocks around the world. In addition, sequence identity with known functional groups suggests enrichments of chemolithotrophic bacteria potentially involved in autotrophic C fixation and inorganic N transformation on rock surfaces. By contrast, bacterial communities in aquatic sediments were more closely related to those in the overlying soils. This is consistent with the similarity in elemental composition between the cave sediment and the overlying soil, implicating the influence of mineral chemistry on cave microhabitat and bacterial composition. These findings provide compelling molecular evidence of the bacterial community heterogeneity in an East Asian cave, which might be controlled by both subsurface and surface environments. PMID:25870592

  7. Out of sight out of mind: current knowledge of Chinese cave fishes.

    PubMed

    Zhao, Y-H; Gozlan, R E; Zhang, C-G

    2011-12-01

    Caves and karsts are among the most threatened ecosystems in the world. They are very fragile, balanced habitats with high levels of endemic species that are extremely sensitive to environmental changes. In recent decades, however, threats from rapid economic growth have increased the need for conservation efforts for cave-dwelling communities. In addition, difficulties in accessing and sampling these habitats mean that they remain as one of the least known ecosystems in the world with modern studies of cave fishes only starting in China during the 1980s. Here, the current status of cave fishes in China is reviewed. China is host to the highest number of cave fish species in the world, with 48 troglobite species out of a total of 101 cave fish species. All of these cave fish species (one order and three families) and half of the genera are endemic to China with Sinocyclocheilus being the most speciose cave fish genus. Species from this genus possess horns and humpbacks resulting from processes of parallel evolution, but the function of these features remains unknown. With the exception of Onychostoma macrolepis distributed in north China, all other species are found in the karst environment of the Yunnan-Guizhou Plateau. Sympatric distribution is common, and sometimes several different cave fish species can be found in the same cave or subterranean river. For this reason, Chinese cave fishes represent an important evolutionary framework.

  8. Sulfur Cycling and Microbial Community Structure in Cave Environment: some geomicrobiological aspects

    NASA Astrophysics Data System (ADS)

    Gulecal, Y.; Temel, M.

    2013-12-01

    In the last decade, cave microbiology has emerged as a growing interdisciplinary field. Because of caves provides a unique subsurface environment for the exploration of microbial life and their roles on biogeochemical cycling under extreme condition. Sulfidic caves form in carbonate rocks where sulfide-rich waters interact with oxygen at the water table or at subterranean springs (1). Terrestrial sulfidic caves and springs are abundant and diverse, as assessed by efforts to characterize cave microbial ecosystems and to understand large scale geochemical processes (2). In this study we examined the geochemical features, microbial community and capacity of sulfur cycling in sulfidic cave ( Kaklik Cave, Turkey ) and its two hot springs. Pyrosequencing were used to understand bacterial diversity and community structure in this study area with contrasting hydrochemial and geological properties. Environmental nucleic acids were extracted, and PCR-directed screens reveal the presence or absence of functional genes, indicating genetic capacity for sulfur cycling. The microbial community displayed a high level of microbial diversity, representing 22 phylum of the Bacteria and 5 phylum of the Archaea. Our results provide a comparative view of the microbial communities and processes involved in sulfur cycling in sulfidic cave environments. 1- Macalady et al. (2007) Extremely acidic, pendulous cave wall biofilms from the Frasassi cave system, Italy. Env.Mic. 9(6), 1402-1414 2- Rossmassler et al. Drivers of epsilonproteobacterial community composition in sulfidic caves and springs.

  9. Cave microbial community composition in oceanic islands: disentangling the effect of different colored mats in diversity patterns of Azorean lava caves.

    PubMed

    Riquelme, Cristina; Rigal, François; Hathaway, Jennifer J M; Northup, Diana E; Spilde, Michael N; Borges, Paulo A V; Gabriel, Rosalina; Amorim, Isabel R; Dapkevicius, Maria de Lurdes N E

    2015-12-01

    Processes determining diversity and composition of bacterial communities in island volcanic caves are still poorly understood. Here, we characterized colored microbial mats in 14 volcanic caves from two oceanic islands of the Azores using 16S rRNA gene sequences. Factors determining community diversity (α) and composition (β) were explored, namely colored mats, caves and islands, as well as environmental and chemical characteristics of caves. Additive partitioning of diversity using OTU occurrence showed a greater influence of β-diversity between islands and caves that may relate to differences in rare OTUs (singletons and doubletons) across scales. In contrast, Shannon diversity partitioning revealed the importance of the lowest hierarchical level (α diversity, colored mat), suggesting a dominance of cosmopolitan OTUs (>1%) in most samples. Cosmopolitan OTUs included members involved in nitrogen cycling, supporting the importance of this process in Azorean caves. Environmental and chemical conditions in caves did not show any significant relationship to OTU diversity and composition. The absence of clear differences between mat colors and across scales may be explained by (1) the geological youth of the cave system (cave communities have not had enough time to diverge) or/and (2) community convergence, as the result of selection pressure in extreme environments.

  10. Time variations of 222Rn concentration and air exchange rates in a Hungarian cave.

    PubMed

    Nagy, Hedvig Éva; Szabó, Zsuzsanna; Jordán, Gyozo; Szabó, Csaba; Horváth, Akos; Kiss, Attila

    2012-09-01

    A long-term radon concentration monitoring was carried out in the Pál-völgy cave, Budapest, Hungary, for 1.5 years. Our major goal was to determine the time dependence of the radon concentration in the cave to characterise the air exchange and define the most important environmental parameters that influence the radon concentration inside the cave. The radon concentration in the cave air was measured continuously by an AlphaGuard radon monitor, and meteorological parameters outside the cave were collected simultaneously. The air's radon concentration in the cave varied between 104 and 7776 Bq m(-3), the annual average value was 1884±85 Bq m(-3). The summer to winter radon concentration ratio was as high as 21.8. The outside air temperature showed the strongest correlation with the radon concentration in the cave, the correlation coefficient (R) was 0.76.

  11. The occurrence of coliform bacteria in the cave waters of Slovak Karst, Slovakia.

    PubMed

    Seman, Milan; Gaálová, Barbora; Cíchová, Marianna; Prokšová, Miloslava; Haviarová, Dagmar; Fľaková, Renáta

    2015-05-01

    The diversity and abundance of coliform bacteria (taxonomically enterobacterias), an important quality water indicator, were determined for four representative caves in Slovak Karst: Domica Cave, Gombasecká Cave, Milada Cave and Krásnohorská Cave. Three hundred and fifty-two enterobacterial isolates were successfully identified by biochemical testing (commercial ENTEROtest 24) and selected isolates confirmed by molecular techniques (PCR, 16S rDNA sequence analysis). A total of 39 enterobacterial species were isolated from cave waters, with predominance of Escherichia coli, Serratia spp. and Enterobacter spp. PCR amplification of lacZ gene is not specific enough to provide a reliable detection of coliform bacteria isolated from the environment. Sequence analysis of 16S rDNA confirmed that all of the selected isolates belong to the family Enterobacteriaceae. In general, physical and chemical parameters of cave waters in Slovak Karst corresponded to national drinking water quality standards.

  12. Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

    PubMed

    Rovenská, K; Thinová, L; Zdímal, V

    2008-01-01

    The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves. The differences in conditions (aerosol size distribution, humidity, radon and its progeny ratio, etc.) are described by the so-called cave factor j. The cave factor is used to correct the dose for workers which is calculated using the ICRP 65 recommendation. In this work, the authors have brought together measured data of aerosol size distribution, unattached and attached fraction activity, and have calculated the so-called cave factor for the Bozkov dolomite cave environment. The dose conversion factors based on measured data and used for evaluating the cave factor were calculated by LUDEP software, which implements HRTM ICRP66.

  13. Full Immersive Virtual Environment Cave[TM] in Chemistry Education

    ERIC Educational Resources Information Center

    Limniou, M.; Roberts, D.; Papadopoulos, N.

    2008-01-01

    By comparing two-dimensional (2D) chemical animations designed for computer's desktop with three-dimensional (3D) chemical animations designed for the full immersive virtual reality environment CAVE[TM] we studied how virtual reality environments could raise student's interest and motivation for learning. By using the 3ds max[TM], we can visualize…

  14. Bacteria associated with the bleached and cave coral Oculina patagonica.

    PubMed

    Koren, Omry; Rosenberg, Eugene

    2008-04-01

    The relative abundance of bacteria in the mucus and tissues of Oculina patagonica taken from bleached and cave (azooxanthellae) corals was determined by analyses of the 16S rRNA genes from cloned libraries of extracted DNA and from isolated colonies. The results were compared to previously published data on healthy O. patagonica. The bacterial community of bleached, cave, and healthy corals were completely different from each other. A tight cluster (>99.5% identity) of bacteria, showing 100% identity to Acinetobacter species, dominated bleached corals, comprising 25% of the 316 clones sequenced. The dominant bacterial cluster found in cave corals, representing 29% of the 97 clones sequenced, showed 98% identity to an uncultured bacterium from the Great Barrier Reef. Vibrio splendidus was the most dominant species in healthy O. patagonica. The culturable bacteria represented 0.1-1.0% of the total bacteria (SYBR Gold staining) of the corals. The most abundant culturable bacteria in bleached, cave, and healthy corals were clusters that most closely matched Microbulbifer sp., an alpha-proteobacterium previously isolated from healthy corals and an alpha-protobacterium (AB026194), respectively. Three generalizations emerge from this study on O. patagonica: (1) More bacteria are associated with coral tissue than mucus; (2) tissue and mucus populations are different; (3) bacterial populations associated with corals change dramatically when corals lack their symbiotic zooxanthellae, either as a result of the bleaching disease or when growing in the absence of light.

  15. Finite element visualization in the cave virtual reality environment

    SciTech Connect

    Plaskacz, E.J.; Kuhn, M.A.

    1996-03-01

    Through the use of the post-processing software, Virtual Reality visualization (VRviz), and the Cave Automatic Virtual Environment (CAVE), finite element representations can be viewed as they would be in real life. VRviz is a program written in ANSI C to translate the mathematical results generated by finite element analysis programs into a virtual representation. This virtual representation is projected into the CAVE environment and the results are animated. The animation is fully controllable. A user is able to translate the image, rotate about any axis and scale the image at any time. The user is also able to freeze the animation at any time step and control the image update rate. This allows the user to navigate around, or even inside, the image in order to effectively analyze possible failure points and redesign as necessary. Through the use of the CAVE and the real life image that is being produced by VRviz, engineers are able to save considerable time, money, and effort in the design process.

  16. Modelling cave flow hydraulics in the Notranjski Kras, Slovenia

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Gabrovsek, Franci

    2015-04-01

    The Notranjski Kras region is a karst region in western Slovenia, developed in Cretaceous limestone. The region is characterised by hilly relief, with peaks reaching 1300 m elevation. Several well-developed cave systems drain the karst aquifer, providing preferential flow pathes along two sections: The Pivka River, which sinks into Postojnska Jama and reappears in Planinska Jama, and the Stržen and Cerkniščica rivers, which sink into Karlovica Jama, flow through Zelške Jama and Tkalca Jama and also reappear in Planinska Jama. Both sub-surface flow pathes merge in Planinska Jama, providing water for the Unica river. The Unica river leaves Planinska Jama via a large karst srping and passes through Planinsko Polje, disappearing again through two groups of ponors, finally emerging in the Ljubljanka Springs at around 300 m asl. The sub-surface flow path through the Postojnska Jama cave system has been monitored with 7 stations distributed along the flow path, monitoring stage and temperature. We have used the stage data to model flow through the cave system with the program package SWMM, simulating the active parts of Postojnska Jama with simplified geometry. From the comparison of stage observations and predictions, we identified key sections in the cave, which control the sub-surface flow, such as passage constrictions, sumps and by-passes. Using a formal inverse procedure, we determined the geometry of this key sections by fitting predicted to observed stages, and we achieved a very high degree of correlation.

  17. [A case of epidermoid tumor inside the Meckel's cave].

    PubMed

    Ohta, H; Ottomo, M; Nakamura, T; Yokota, A

    1997-10-01

    An epidermoid tumor inside the Meckel's cave is rare. The symptoms caused by this tumor include trigeminal neuralgia, facial hypesthesia and paresis of the 3rd, 4th and 6th nerves. A case of epidermoid tumor inside Meckel's cave was presented. A 54-year-old female who had complained of 3rd nerve palsy with right facial hypesthesia since 3 years before was referred to our clinic. Magnetic resonance imaging (MRI) showed the tumor at Meckel's cave. The tumor removal was performed using the orbito-zygomatic approach. To avoid injury of the internal carotid artery and nerves inside the cavernous sinus, removal of the tumor inside the capsule was carried out leaving the capsule. Postoperatively, the tumor removal was confirmed by MRI and improvement of the 3rd and the 5th nerve palsy was obtained three months after surgery. This case suggests that the capsule of the tumor inside the Meckel's cave should be allowed to remain to avoid injury of the adjacent 4th, 5th and 6th nerves and of the internal carotid artery.

  18. The relationship between caves minerals and hypogene speleogenesis along the Cerna Valley (SW Romania)

    NASA Astrophysics Data System (ADS)

    Onac, B. P.; Sumrall, J.; Tamas, T.; Povara, I.; Veres, D.; Darmiceanu, V.; Lascu, C.

    2009-04-01

    Over 100 caves are known to develop in the Jurassic and Cretaceous limestone that outcrops on both sides of the Cerna Valley in southwestern Romania. High temperature anomalies are rather uncommon in the cave environment; however, in certain caves in the lower part of Cerna Valley one can measure air temperatures as high as 40°C. This situation is due to the presence of thermal water pooling or flowing through the caves or to the hot steam that rises along fractures from deeper thermal water pools. During the long evolution of the thermo-mineral activity along the Cerna Valley interaction has occurred on a wide scale between the cave host rock or/and cave sediments and the ascending hot steam or/and thermal solutions of all types (mainly sulfide-rich). The present work documents the products of these processes and record the occurrence of twenty-four secondary cave minerals (both of primarily or replacement origin) precipitated under particular cave environments. Among these, glauberite, apjonite, halotrichite, pickeringite, rapidcreekite, tamarugite, and darapskite are the most interesting. The mineral samples were investigated by means of X-ray diffraction, electron microprobe, Fourier-transformed infrared spectroscopy, and scanning electron microscope analyses with the scope of linking the cave minerals with possible hypogene speleogenetic processes. The isotopic measurements (δ34S) performed on sulfate speleothems contribute valuable information on both minerals and caves origin. Apart from two minerals (i.e., calcite and gypsum), which were identified in every cave investigated so far, all the others fall into three distinct associations that have resulted from specific reactions under highly particular settings in Diana (sulfate-dominated association), Adam (phosphate-dominated), and Great Sălitrari (sulfate/phosphate/nitrate-rich association) caves. These three remarkable cave occurrences are presented along with morphological features that confirm the

  19. Cryogenic cave carbonates as an archive of Late Pleistocene permafrost in the Ural Mountains: preliminary results

    NASA Astrophysics Data System (ADS)

    Dublyansky, Yuri; Kadebskaya, Olga; Cheng, Hai; Luetscher, Mark; Spötl, Christoph

    2015-04-01

    A specific type of cave deposits, cryogenic cave carbonates (CCCs), was discovered in the late 1980s in several caves of Central Europe. Unlike 'common' speleothems that form primarily due to degassing of CO2 from Ca2+ and HCO3- -rich waters, CCCs form by freezing-induced segregation (Žák et al., 2004). The formation of CCCs, hence, requires the presence of both liquid water and freezing temperatures. The latter combination may occur in caves in two situations: (1) freezing-thawing cycles in cave entrance zones; and (2) degrading permafrost conditions, when the active layer reaches the cave ceiling, whilst the deeper parts of the cave remain frozen. The latter situation is associated with a particular type of CCCs, which can be used as a marker for permafrost conditions. Because cave carbonates can be accurately dated using the U/Th method, CCCs may be used to identify events of (degrading) palaeo-permafrost conditions. In this study, CCCs were identified and sampled in four caves, located along a 1000 km-long transect from the northern to the southern Ural Associating the CCCs to permafrost conditions was possible on the basis of field observations (locations deep inside the cave, far from entrance zones) and stable isotope properties (strongly depleted δ18O values, inverse correlation between δ18O and δ13C). Chaikovskiy et al. (2014) reported five U/Th analyses of CCC from three caves: 16.7 ka and 104.8 ka (Divja Cave, northern Ural); and 13.4 ka, 86.5 ka and 125.3 ka (Rossijskaya and Usvinskaya Caves, central Ural). In this study we report 25 additional U/Th ages from northern and central Ural, as well as the first CCC age from southern Ural (Shulgan-Tash Cave). Most of the younger ages (

  20. On developing thermal cave detection techniques for earth, the moon and mars

    USGS Publications Warehouse

    Wynne, J.J.; Titus, T.N.; Chong, Diaz G.

    2008-01-01

    The purpose of this study is to (1) demonstrate the viability of detecting terrestrial caves at thermal-infrared wavelengths, (2) improve our understanding of terrestrial cave thermal behavior, (3) identify times of day when cave openings have the maximum thermal contrast with the surrounding surface regolith, and (4) further our understanding of how to detect caves on Earth, the Moon and Mars. We monitored the thermal behavior of two caves in the Atacama Desert of northern Chile. Through this work, we identified times when temperature contrasts between entrance and surface were greatest, thus enabling us to suggest optimal overflight times. The largest thermal contrast for both caves occurred during mid-day. One cave demonstrated thermal behavior at the entrance suggestive of cold-trapping, while the second cave demonstrated temperature shifts suggestive of airflow. We also collected thermograms without knowing optimal detection times; these images suggest both caves may also be detectable during off-peak times. We suggest cave detection using thermal remote sensing on Earth and other planetary objects will be limited by (1) capturing imagery in the appropriate thermal wavelength, (2) the size of cave entrance vs. the sensor's spatial resolution, (3) the viewing angle of the platform in relation to the slope trajectory of the cave entrance, (4) the strength of the thermal signal associated with the cave entrance, and (5) the time of day and season of thermal image capture. Through this and other studies, we will begin to identify the range of conditions under which caves are detectable in the thermal infrared and thus improve our detection capabilities of these features on Earth, the Moon and Mars. ?? 2008 Elsevier B.V.

  1. A post-wildfire response in cave dripwater chemistry

    NASA Astrophysics Data System (ADS)

    Nagra, Gurinder; Treble, Pauline C.; Andersen, Martin S.; Fairchild, Ian J.; Coleborn, Katie; Baker, Andy

    2016-07-01

    Surface disturbances above a cave have the potential to impact cave dripwater discharge, isotopic composition and solute concentrations, which may subsequently be recorded in the stalagmites forming from these dripwaters. One such disturbance is wildfire; however, the effects of wildfire on cave chemistry and hydrology remains poorly understood. Using dripwater data monitored at two sites in a shallow cave, beneath a forest, in southwest Australia, we provide one of the first cave monitoring studies conducted in a post-fire regime, which seeks to identify the effects of wildfire and post-fire vegetation dynamics on dripwater δ18O composition and solute concentrations. We compare our post-wildfire δ18O data with predicted dripwater δ18O using a forward model based on measured hydro-climatic influences alone. This helps to delineate hydro-climatic and fire-related influences on δ18O. Further we also compare our data with both data from Golgotha Cave - which is in a similar environment but was not influenced by this particular fire - as well as regional groundwater chemistry, in an attempt to determine the extent to which wildfire affects dripwater chemistry. We find in our forested shallow cave that δ18O is higher after the fire relative to modelled δ18O. We attribute this to increased evaporation due to reduced albedo and canopy cover. The solute response post-fire varied between the two drip sites: at Site 1a, which had a large tree above it that was lost in the fire, we see a response reflecting both a reduction in tree water use and a removal of nutrients (Cl, Mg, Sr, and Ca) from the surface and subsurface. Solutes such as SO4 and K maintain high concentrations, due to the abundance of above-ground ash. At Site 2a, which was covered by lower-middle storey vegetation, we see a solute response reflecting evaporative concentration of all studied ions (Cl, Ca, Mg, Sr, SO4, and K) similar to the trend in δ18O for this drip site. We open a new avenue for

  2. Millennial Scale Cycles from Speleothems of the Gibraltar Caves

    NASA Astrophysics Data System (ADS)

    Boyd, Meighan; Mattey, Dave; Atkinson, Tim; Hoffmann, Dirk

    2016-04-01

    The Rock of Gibraltar contains many solution caves which initially formed near sea level and now span elevations to over 300m as a result of slow uplift over time. In the modern climate, Gibraltar holds an important position near the southern limit of the tracks taken by the depressions that deliver rainfall to Europe from the North Atlantic sector of the atmosphere. Monitoring in St. Michaels and Ragged Staff caves has been carried out since 2004 by monthly sampling and deployment of logging instruments which reveals that speleothem growth is most strongly influenced by seasonally reversing cave ventilation that permeates the entire rock. The results provide unprecedented insight into how cave environments respond to seasonal change, variations in sea level and neotectonic uplift and the ways that regional climate is recorded as chemical proxies in an evolving cave environment. We present an overview of the results of this proxy record of precipitation, sea level and environmental change, including new analysis within this 500ka record. A general mean isotopic composition of 1ka time slices have been stacked into a preliminary record from over twenty speleothems. Within this we look at higher resolution time slices to examine the occurrence of millennial scale cycles which occur within the Gibraltar record. During glacial maxima, the Gibraltar record shows elevated δ18O and associated higher δ13C caused by greater degassing or lower soil pCO2 from weakened vegetative activity during cool arid glacials. Highly resolved millennial scale warming events which seem to match the Greenland ice core record give insights into SST changes and atmospheric reorganization at Gibraltar.

  3. Mapping planetary caves with an autonomous, heterogeneous robot team

    NASA Astrophysics Data System (ADS)

    Husain, Ammar; Jones, Heather; Kannan, Balajee; Wong, Uland; Pimentel, Tiago; Tang, Sarah; Daftry, Shreyansh; Huber, Steven; Whittaker, William L.

    Caves on other planetary bodies offer sheltered habitat for future human explorers and numerous clues to a planet's past for scientists. While recent orbital imagery provides exciting new details about cave entrances on the Moon and Mars, the interiors of these caves are still unknown and not observable from orbit. Multi-robot teams offer unique solutions for exploration and modeling subsurface voids during precursor missions. Robot teams that are diverse in terms of size, mobility, sensing, and capability can provide great advantages, but this diversity, coupled with inherently distinct low-level behavior architectures, makes coordination a challenge. This paper presents a framework that consists of an autonomous frontier and capability-based task generator, a distributed market-based strategy for coordinating and allocating tasks to the different team members, and a communication paradigm for seamless interaction between the different robots in the system. Robots have different sensors, (in the representative robot team used for testing: 2D mapping sensors, 3D modeling sensors, or no exteroceptive sensors), and varying levels of mobility. Tasks are generated to explore, model, and take science samples. Based on an individual robot's capability and associated cost for executing a generated task, a robot is autonomously selected for task execution. The robots create coarse online maps and store collected data for high resolution offline modeling. The coordination approach has been field tested at a mock cave site with highly-unstructured natural terrain, as well as an outdoor patio area. Initial results are promising for applicability of the proposed multi-robot framework to exploration and modeling of planetary caves.

  4. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders.

    PubMed

    Carver, Linnea M; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species.

  5. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders

    PubMed Central

    Carver, Linnea M.; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S.

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species. PMID:27280416

  6. Bearings: Technology and needs

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1982-01-01

    A brief status report on bearing technology and present and near-term future problems that warrant research support is presented. For rolling element bearings a material with improved fracture toughness, life data in the low Lambda region, a comprehensive failure theory verified by life data and incorporated into dynamic analyses, and an improved corrosion resistant alloy are perceived as important needs. For hydrodynamic bearings better definition of cavitation boundaries and pressure distributions for squeeze film dampers, and geometry optimization for minimum power loss in turbulent film bearings are needed. For gas film bearings, foil bearing geometries that form more nearly optimum film shapes for maximum load capacity, and more effective surface protective coatings for high temperature operation are needed.

  7. [Variation Characteristics of Cave Water Hydrogeochemistry in Naduo Cave of Guizhou and Its Implications for Environment Research].

    PubMed

    Shen, Wei; Wang, Jian-li; Wang, Jia-lu; Jiang, Xian-shu; Mao, Qing-ya; Chen, Zhi-qiu; Liu, Xiao

    2015-12-01

    During the period from December 2012 to December 2014, three dripping water sites (S1, S2, S3) and one pool water site (SC) have been selected for a long-term monitoring of geochemical indexes in Naduo Cave, Guanling county of Guizhou Province, China. Based on the local meteorological data, this paper analyzed the seasonal change of hydro-geochemical indicators and their feedbacks to climate events. The results indicated that the hydro-geochemical type of cave water was HCO₃⁻-Ca²⁺. Dripping water and pool water were in deposition all the year, except in the month with the maximum precipitation. There were some discrepancies of main ions' concentration among three dripping water sites due to the difference of the migration pathways and migration time. Affected by mixed water and high CO₂ concentration of cave air, the ion concentration of pool water was higher than dripping water, and there was considerable fluctuation. The geochemistry indexes of water in Naduo Cave showed extraordinary seasonal variation rules and could perfectly respond to the external climate environment. The concentration of ions was sensitive to the response of the annual precipitation change caused by extreme climate events. During the rainy season, the concentrations of Ca²⁺, Mg²⁺ and SO₄²⁻ in 2013 were relatively higher and more stable than those in 2014. The response time and susceptivity of each monitoring site were inconsistent.

  8. Bear Spray Safety Program

    USGS Publications Warehouse

    Blome, C.D.; Kuzniar, R.L.

    2009-01-01

    A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

  9. Bearing restoration by grinding

    NASA Technical Reports Server (NTRS)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  10. Linear magnetic bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A linear magnetic bearing system having electromagnetic vernier flux paths in shunt relation with permanent magnets, so that the vernier flux does not traverse the permanent magnet, is described. Novelty is believed to reside in providing a linear magnetic bearing having electromagnetic flux paths that bypass high reluctance permanent magnets. Particular novelty is believed to reside in providing a linear magnetic bearing with a pair of axially spaced elements having electromagnets for establishing vernier x and y axis control. The magnetic bearing system has possible use in connection with a long life reciprocating cryogenic refrigerator that may be used on the space shuttle.

  11. From rain to cave drip water: Hydraulic response time and water transfer time at Bunker Cave (NW Germany)

    NASA Astrophysics Data System (ADS)

    Riechelmann, Sylvia; Schröder-Ritzrau, Andrea; Spötl, Christoph; Riechelmann, Dana F. C.; Richter, Detlev K.; Mangini, Augusto; Frank, Norbert; Immenhauser, Adrian

    2016-04-01

    Speleothem based palaeoclimate studies considerably increased during the last two decades. Processes in the soil and karst zone influence the proxies applied on the speleothem climate archive. Thus, caves are monitored for a wide range of environmental parameters. These monitoring programmes mostly focus on seasonal variations but less so on the multi-annual time scale. The present study analyses long-term trends from a seven year-long monitoring of Bunker Cave, NW Germany, in order to assess the hydraulic response time and transfer time of meteoric water from the surface to the cave. Therefore, drip rates of all sites were measured manually with a stopwatch and rain, soil as well as drip waters were collected in a monthly to bimonthly resolution. Subsequently, the oxygen and hydrogen isotopic compositions of the waters were analysed. Furthermore, the coefficient of permeability was calculated from granulometric analyses performed on soil samples collected above Bunker Cave. The annual mean drip rates of all drip sites except one display the same long-term trend. In the case of Bunker Cave, correlations of the annual mean drip rate of each site with annual precipitation and infiltration demonstrate that the annual infiltration and thus, the annual precipitation control the interannual drip-rate variability. Therefore, the hydraulic response time does not show a temporal offset. The annual mean oxygen isotopic compositions of all drip waters except one display the same long-term trend, whilst the annual mean hydrogen isotope ratios of all drip sites display the same trend. In combination with the results of the coefficient of permeability, correlations of soil and drip water annual mean oxygen and hydrogen isotopic composition with atmospheric temperature reveal water transfer times for soil water of 3 to 6 months for 40 cm soil-depth and ca. 1 year for 70 cm soil-depth. Finally, the water reaches the cave after three years transfer time. As a consequence, a

  12. Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

    PubMed Central

    Bover, Pere; Soibelzon, Leopoldo; Schubert, Blaine W.; Prevosti, Francisco; Prieto, Alfredo; Martin, Fabiana; Austin, Jeremy J.; Cooper, Alan

    2016-01-01

    The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear (Tremarctos ornatus), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears (Tremarctos), South American short-faced bears (Arctotherium) and North American short-faced bears (Arctodus) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears (Arctodus and Arctotherium), potentially as an adaptation to dominate competition for megafaunal carcasses. PMID:27095265

  13. Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America.

    PubMed

    Mitchell, Kieren J; Bray, Sarah C; Bover, Pere; Soibelzon, Leopoldo; Schubert, Blaine W; Prevosti, Francisco; Prieto, Alfredo; Martin, Fabiana; Austin, Jeremy J; Cooper, Alan

    2016-04-01

    The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear (Tremarctos ornatus), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears (Tremarctos), South American short-faced bears (Arctotherium) and North American short-faced bears (Arctodus) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears (Arctodus and Arctotherium), potentially as an adaptation to dominate competition for megafaunal carcasses.

  14. Radon hazards, geology, and exposure of cave users: a case study and some theoretical perspectives.

    PubMed

    Gillmore, G K; Sperrin, M; Phillips, P; Denman, A

    2000-07-01

    The concerns over the risks to human health from radon in underground caves are poorly documented, unlike in workplace or domestic environments where exposures are relatively well known. In U.K. caves, radon has been identified as occurring at elevated levels; but with the exception of major show caves, its impact and risk to the many groups who use the caves have thus far received inadequate attention. This paper presents a survey performed in a relatively "low-risk" geographical area of the United Kingdom and quantifies the risk of exposure in this cave environment. Radon levels up to 12,552 Bq m(-3) were measured: Such concentrations are very high but are likely to underestimate the levels in many other parts of the cave system, for reasons associated with cave architecture and meteorology. This study confirms previous workers' conclusions that long-term users of deep caves, as opposed to rock shelters, are at risk. Annual doses to certain groups of cave users have been calculated to be as high as 120 mSv, a very high value. The study also demonstrates that there is variation both within and between caves as a result of subtleties of the bedrock geology, fault patterns, and weathering. This paper sets out a theoretical model.

  15. Geologic context of large karst springs and caves in the Ozark National Scenic Riverways, Missouri

    USGS Publications Warehouse

    Weary, David J.; Orndorff, Randall C.

    2016-01-01

    The ONSR is a karst park, containing many springs and caves. The “jewels” of the park are large springs, several of first magnitude, that contribute significantly to the flow and water quality of the Current River and its tributaries. Completion of 1:24,000-scale geologic mapping of the park and surrounding river basin, along with synthesis of published hydrologic data, allows us to examine the spatial relationships between the springs and the geologic framework to develop a conceptual model for genesis of these springs. Based on their similarity to mapped spring conduits, many of the caves in the ONSR are fossil conduit segments. Therefore, geologic control on the evolution of the springs also applies to speleogenesis in this part of the southern Missouri Ozarks.Large springs occur in the ONSR area because: (1) the Ozark aquifer, from which they rise, is chiefly dolomite affected by solution via various processes over a long time period, (2) Paleozoic hypogenic fluid migration through these rocks exploited and enhanced flow-paths, (3) a consistent and low regional dip of the rocks off of the Salem Plateau (less than 2° to the southeast) allows integration of flow into large groundwater basins with a few discreet outlets, (4) the springs are located where the rivers have cut down into structural highs, allowing access to water from stratigraphic units deeper in the aquifer thus allowing development of springsheds that have volumetrically larger storage than smaller springs higher in the section, and (5) quartz sandstone and bedded chert in the carbonate stratigraphic succession that are locally to regionally continuous, serve as aquitards that locally confine groundwater up dip of the springs creating artesian conditions. This subhorizontal partitioning of the Ozark aquifer allows contributing areas for different springs to overlap, as evidenced by dye traces that cross adjacent groundwater basin boundaries, and possibly contributes to alternate flow routes

  16. Potential effects of recurrent low oxygen conditions on the Illinois Cave amphipod

    USGS Publications Warehouse

    Panno, S.V.; Hackley, Keith C.; Kelly, W.R.; Hwang, H.-H.; Wilhelm, F.M.; Taylor, S.J.; Stiff, B.J.

    2006-01-01

    The caves of Illinois' sinkhole plain are the sole habitat of the Illinois Cave amphipod (Gammarus acherondytes), a federally endangered species. The sinkhole plain is a hydrologically-connected sequence of karstified limestone that constitutes an extensive karst aquifer which serves as an important source of potable water for area residents. During this investigation, we examined the ground-water quality in caves within two ground-water basins: 1) Illinois Caverns, where the amphipod is now present after previously reported to have been extirpated from the lower reaches, and 2) Stemler Cave, where the amphipod is reported to have been extirpated. The chemical composition of cave streams in Illinois Caverns and Stemler Cave were compared to determine which parameters, if any, could have contributed to the loss of G. acherondytes from Stemler Cave. Stream water in Stemler Cave contained higher concentrations of organic carbon, potassium, silica, chloride, fluoride, sulfate, iron and manganese than Illinois Caverns. Perhaps most importantly, dissolved oxygen (DO) concentrations in Stemler Cave were, during periods of low flow, substantially lower than in Illinois Caverns. Based on land use, there are probably at least eight times more private septic systems in the Stemler Cave ground-water basin than in the Illinois Caverns ground-water basin. Low DO concentrations were likely the result of microbial breakdown of soil organic matter and wastewater treatment system effluent, and the oxidation of pyrite in bedrock. The near-hypoxic DO in Stemler Cave that occurred during low-flow conditions, and, we speculate, a limited range of G. acherondytes within the Stemler Cave ground-water basin due to a metabolic advantage of the stygophilic aquatic invertebrates over the stygobitic G. acherodytes, resulted in the apparent loss of G. acherondytes from Stemler Cave.

  17. Reconciling Mining with the Conservation of Cave Biodiversity: A Quantitative Baseline to Help Establish Conservation Priorities

    PubMed Central

    Prous, Xavier; Zampaulo, Robson; Giannini, Tereza C.; Imperatriz-Fonseca, Vera L.; Maurity, Clóvis; Oliveira, Guilherme; Brandi, Iuri V.; Siqueira, José O.

    2016-01-01

    Caves pose significant challenges for mining projects, since they harbor many endemic and threatened species, and must therefore be protected. Recent discussions between academia, environmental protection agencies, and industry partners, have highlighted problems with the current Brazilian legislation for the protection of caves. While the licensing process is long, complex and cumbersome, the criteria used to assign caves into conservation relevance categories are often subjective, with relevance being mainly determined by the presence of obligate cave dwellers (troglobites) and their presumed rarity. However, the rarity of these troglobitic species is questionable, as most remain unidentified to the species level and their habitats and distribution ranges are poorly known. Using data from 844 iron caves retrieved from different speleology reports for the Carajás region (South-Eastern Amazon, Brazil), one of the world's largest deposits of high-grade iron ore, we assess the influence of different cave characteristics on four biodiversity proxies (species richness, presence of troglobites, presence of rare troglobites, and presence of resident bat populations). We then examine how the current relevance classification scheme ranks caves with different biodiversity indicators. Large caves were found to be important reservoirs of biodiversity, so they should be prioritized in conservation programs. Our results also reveal spatial autocorrelation in all the biodiversity proxies assessed, indicating that iron caves should be treated as components of a cave network immersed in the karst landscape. Finally, we show that by prioritizing the conservation of rare troglobites, the current relevance classification scheme is undermining overall cave biodiversity and leaving ecologically important caves unprotected. We argue that conservation efforts should target subterranean habitats as a whole and propose an alternative relevance ranking scheme, which could help simplify the

  18. Reconciling Mining with the Conservation of Cave Biodiversity: A Quantitative Baseline to Help Establish Conservation Priorities.

    PubMed

    Jaffé, Rodolfo; Prous, Xavier; Zampaulo, Robson; Giannini, Tereza C; Imperatriz-Fonseca, Vera L; Maurity, Clóvis; Oliveira, Guilherme; Brandi, Iuri V; Siqueira, José O

    2016-01-01

    Caves pose significant challenges for mining projects, since they harbor many endemic and threatened species, and must therefore be protected. Recent discussions between academia, environmental protection agencies, and industry partners, have highlighted problems with the current Brazilian legislation for the protection of caves. While the licensing process is long, complex and cumbersome, the criteria used to assign caves into conservation relevance categories are often subjective, with relevance being mainly determined by the presence of obligate cave dwellers (troglobites) and their presumed rarity. However, the rarity of these troglobitic species is questionable, as most remain unidentified to the species level and their habitats and distribution ranges are poorly known. Using data from 844 iron caves retrieved from different speleology reports for the Carajás region (South-Eastern Amazon, Brazil), one of the world's largest deposits of high-grade iron ore, we assess the influence of different cave characteristics on four biodiversity proxies (species richness, presence of troglobites, presence of rare troglobites, and presence of resident bat populations). We then examine how the current relevance classification scheme ranks caves with different biodiversity indicators. Large caves were found to be important reservoirs of biodiversity, so they should be prioritized in conservation programs. Our results also reveal spatial autocorrelation in all the biodiversity proxies assessed, indicating that iron caves should be treated as components of a cave network immersed in the karst landscape. Finally, we show that by prioritizing the conservation of rare troglobites, the current relevance classification scheme is undermining overall cave biodiversity and leaving ecologically important caves unprotected. We argue that conservation efforts should target subterranean habitats as a whole and propose an alternative relevance ranking scheme, which could help simplify the

  19. Calculating flux to predict future cave radon concentrations.

    PubMed

    Rowberry, Matt D; Martí, Xavi; Frontera, Carlos; Van De Wiel, Marco J; Briestenský, Miloš

    2016-06-01

    Cave radon concentration measurements reflect the outcome of a perpetual competition which pitches flux against ventilation and radioactive decay. The mass balance equations used to model changes in radon concentration through time routinely treat flux as a constant. This mathematical simplification is acceptable as a first order approximation despite the fact that it sidesteps an intrinsic geological problem: the majority of radon entering a cavity is exhaled as a result of advection along crustal discontinuities whose motions are inhomogeneous in both time and space. In this paper the dynamic nature of flux is investigated and the results are used to predict cave radon concentration for successive iterations. The first part of our numerical modelling procedure focuses on calculating cave air flow velocity while the second part isolates flux in a mass balance equation to simulate real time dependence among the variables. It is then possible to use this information to deliver an expression for computing cave radon concentration for successive iterations. The dynamic variables in the numerical model are represented by the outer temperature, the inner temperature, and the radon concentration while the static variables are represented by the radioactive decay constant and a range of parameters related to geometry of the cavity. Input data were recorded at Driny Cave in the Little Carpathians Mountains of western Slovakia. Here the cave passages have developed along splays of the NE-SW striking Smolenice Fault and a series of transverse faults striking NW-SE. Independent experimental observations of fault slip are provided by three permanently installed mechanical extensometers. Our numerical modelling has revealed four important flux anomalies between January 2010 and August 2011. Each of these flux anomalies was preceded by conspicuous fault slip anomalies. The mathematical procedure outlined in this paper will help to improve our understanding of radon migration

  20. Colonization and speciation of cave animals in the Philippines

    NASA Astrophysics Data System (ADS)

    Husana, D.; Yamamuro, M.; Kase, T.

    2012-12-01

    Island-like situation of caves resulted to species isolation while organism's phenotypic plasticity allows the animal to cope with the cave's environment. These conditions eventually lead to organism's speciation through genetic differentiation. Combined morphological and molecular analyses provided insights on the speciation events and colonization of the subterranean ecosystem. Morphological analysis of hypogean species, known as troglobite, and its epigean congeners showed the interesting differences in their characters. Troglobite exhibited cave adaptations such as degenerated eyesight, enlargement or elongation of ambulatory organs, loss of pigmentation and development of other useful organs that favors their survival in the dark cave environment. Molecular clock estimation based on the substitution rate of 0.88% per million years established for 16S rRNA for the grapsid crab genus Sesarma suggested that the troglobitic Sundathelphusa species colonized the cave habitat in Samar Island in the late Miocene epoch and started to diverge from its epigean ancestor ca. 5.92 mya. Interestingly, the five species of the genus Sundathelphusa from Bohol Island comprising of both hypogean and epigean species (S. cavernicola, S. sottoae, S. vediniki, S. urichi and S. boex) occupy a single clade with divergence time from its sister clade ca. 2.58 mya. This phenomenon suggests two possible interpretations of the existence of Bohol species: (1) they belong to a single species with regular genetic flow from their surface relative and that their character differences can be best interpreted as ecophenotypic, or, (2) the speciation event was very rapid and quite recent. Mitochondrial DNA sequences of 430 base pairs of the large subunit rRNA (16S rRNA) revealed the phylogenetic relationships of the genus Sundathelphusa suggesting a multiple colonizations of caves. The speciation events coincided with the timing of the eustatic sea level fluctuation and geologic changes in the

  1. Low cost lobed bearing

    NASA Technical Reports Server (NTRS)

    Schuller, F. T.

    1970-01-01

    Separate sectors for each lobed area of the bearing are assembled into the bearing housing individually and bolted tightly against the housing inside diameter. The center of a grinding wheel and the center of the housing are offset, resulting in the desired inner radius and tilt of the sector.

  2. Damper bearing rotordynamics

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1990-01-01

    High side loads reduce the life of the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP) bearings. High stiffness damper seals were recommended to reduce the loads on the pump and turbine end bearings in the HPOTP. The seals designed for use on the pump end are expected to adequately reduce the bearing loads; the predicted performance of the planned turbine end seal is marginal. An alternative to the suggested turbine end seal design is a damper bearing with radial holes from the pressurized center of the turbopump rotor, feeding a smooth land region between two rough-stator/smooth-rotor annular seals. An analysis was prepared to predict the leakage and rotor dynamic coefficients (stiffness, damping, and added mass) of the damper bearing. Governing equations of the seal analysis modified to model the damper bearing; differences between the upstream conditions of the damper bearing and a typical annular seal; prediction of the damper bearing analysis; and assumptions of the analysis which require further investigation are described.

  3. Bearing fatigue investigation 3

    NASA Technical Reports Server (NTRS)

    Nahm, A. H.; Bamberger, E. N.; Signer, H. R.

    1982-01-01

    The operating characteristics of large diameter rolling-element bearings in the ultra high speed regimes expected in advanced turbine engines for high performance aircraft were investigated. A high temperature lubricant, DuPont Krytox 143 AC, was evaluated at bearing speeds to 3 million DN. Compared to the results of earlier, similar tests using a MIL-L-23699 (Type II) lubricant, bearings lubricated with the high density Krytox fluid showed significantly higher power requirements. Additionally, short bearing lives were observed when this fluid was used with AISI M50 bearings in an air atmosphere. The primary mode of failure was corrosion initiated surface distress (fatigue) on the raceways. The potential of a case-carburized bearing to sustain a combination of high-tangential and hertzian stresses without experiencing race fracture was also investigated. Limited full scale bearing tests of a 120 mm bore ball bearing at a speed of 25,000 rpm (3 million DN) indicated that a carburized material could sustain spalling fatigue without subsequent propagation to fracture. Planned life tests of the carburized material had to be aborted, however, because of apparent processing-induced material defects.

  4. Cylindrical bearing analysis

    NASA Technical Reports Server (NTRS)

    Kleckner, R. J.; Pirvics, J.

    1981-01-01

    Program CYBEAN computes behavior of rolling-element bearings including effects of bearing geometry, shaft misalinement, and temperature. Accurate assessment is possible for various outer-ring and housing configurations. CYBEAN is structured for coordinated execution of modules that perform specific analytical tasks. It is written in FORTRAN IV for use on the UNIVAC 1100/40 computer.

  5. Arcturus and the Bears

    NASA Astrophysics Data System (ADS)

    Antonello, E.

    2009-08-01

    Arcturus is the brightest star in Bootes. The ancient Greek name Arktouros means Bear Guard. The star, however, is not close to Ursa Maior (Big She-Bear) and Ursa Minor (Little She-Bear), as the name would suggest. This curious discrepancy could be explained by the star proper motion, assuming the name Bear Guard is a remote cultural heritage. The proper motion analysis could allow us to get an insight also into an ancient myth regarding Ursa Maior. Though we cannot explain scientifically such a myth, some interesting suggestions can be obtained about its possible origin, in the context of the present knowledge of the importance of the cult of the bear both during the Palaeolithic times and for several primitive populations of modern times, as shown by the ethnological studies.

  6. Drip-Water Temperatures in Caves: Surface Signals or Cave Processes? - Implications for Speleothem Deposits and Paleoclimate Archives

    NASA Astrophysics Data System (ADS)

    Andersen, M. S.; Cuthbert, M. O.; Rau, G. C.; Baker, A.; Roshan, H.; Rutlidge, H.; Marjo, C.; Markowska, M.; Graham, P. W.; Mariethoz, G.

    2013-12-01

    Caves offer a unique opportunity to enter the subsurface to study vadose zone hydrological processes. Limestone caves, with their speleothem deposits, offer additional advantages as archives of past climate. As such they can serve as observatories for past and present hydrological observations. Correct interpretation of past climates using speleothem deposits requires a systematic understanding of karst physico-chemical processes. With the aim of studying near surface flow and heat transport processes, a series of controlled recharge experiments were carried out above Wellington Caves, located in the temperate semi-arid zone of NSW, Australia. Variable amounts of cooled water were irrigated onto the land surface on four consecutive days in January 2013. The applied recharge rates varied from 40 to 70 mm/d and are comparable to mid-sized recharge events. The temperature of the applied water was varied from 0.3 °C to 24.2 °C using ice. Miniature self-contained temperature loggers (DST micro-T, Star Oddi, Iceland) were deployed to measure the soil temperature and strapped directly on to stalactite features inside the cave located about 2 m below the surface. The stalactites have previously activated regularly by mid-sized precipitation events. Below on the cave floor, drip-loggers (Stalagmate, Driptych, UK) were aligned with the stalactites to capture onset of flow as well as drip rates. Three events of inflow were observed in the initially dry cave. The first irrigation did not produce any inflow since the amount of water applied was not large enough to overcome the soil moisture deficit. Subsequently, each inflow had a higher peak drip rate and duration than the previous event. Surprisingly the stalagmite temperature results showed no discernible effect of the cool water applied to the land surface, despite large changes in the soil temperature caused by the irrigation water. Considering the shallow location of the studied cave this highlights that the temperature

  7. A Critical Mapping of Practice-Based Research as Evidenced by Swedish Architectural Theses

    ERIC Educational Resources Information Center

    Buchler, Daniela; Biggs, Michael A. R.; Stahl, Lars-Henrik

    2011-01-01

    This article presents an investigation that was funded by the Swedish Institute into the role of creative practice in architectural research as evidenced in Swedish doctoral theses. The sample was mapped and analysed in terms of clusters of interest, approaches, cultures of knowledge and uses of creative practice. This allowed the identification…

  8. 75 FR 30309 - Revisions to the Requirements for Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... system internal controls. DATES: Submit comments on or before July 1, 2010. ADDRESSES: Mail or deliver... Evidencing Systems. This proposed revision clarifies the internal controls required in 39 CFR 501.15(i...'s internal controls related to the CMRS system and any other applications and...

  9. 75 FR 56471 - Revisions to the Requirements for Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... manufacture and distribute postage evidencing systems. This revision clarifies the internal controls required... opinion on the design and operating effectiveness of the RC's internal controls related to the CMRS system... operating effectiveness of the internal controls related to the PC Postage system and any other......

  10. Enhancing Student Motivation as Evidenced by Improved Academic Growth and Increased Work Completion.

    ERIC Educational Resources Information Center

    Belcher, Gay; Macari, Nancy

    This project evaluated a program for enhancing student motivation as evidenced by improved academic growth and increased work completion. The targeted population consisted of fifth graders in a small school in a medium-sized rural community in the Midwest. The problem of lack of achievement motivation and lack of student concern about academic…

  11. 77 FR 23396 - Revisions to the Requirements for Authority To Manufacture and Distribute Postage Evidencing Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... any testing concerning the security or revenue protection features, capabilities, or failings of any PES, as well as all potential security weaknesses or methods of tampering with the PES. This rule... Reporting Postage Evidencing System security weaknesses. * * * * * (b) * * * (3) Cyber attacks that...

  12. Patterns of faunal extinction and paleoclimatic change from mid-Holocene mammoth and polar bear remains, Pribilof Islands, Alaska

    NASA Astrophysics Data System (ADS)

    Veltre, Douglas W.; Yesner, David R.; Crossen, Kristine J.; Graham, Russell W.; Coltrain, Joan B.

    2008-07-01

    Qagnaxˆ Cave, a lava tube cave on St. Paul Island in the Pribilofs, has recently produced a mid-Holocene vertebrate faunal assemblage including woolly mammoth, polar bear, caribou, and Arctic fox. Several dates on the mammoth remains converge on 5700 14C yr BP. These dates, ~ 2300 yr younger than mammoth dates previously published from the Pribilof Islands, make these the youngest remains of proboscideans, and of non-extinct Quaternary megafauna, recovered from North America. Persistence of mammoths on the Pribilofs is most parsimoniously explained by the isolation of the Pribilofs and the lack of human presence in pre-Russian contact times, but an additional factor may have been the local existence of high-quality forage in the form of grasses enriched by nutrients derived from local Holocene tephras. This interpretation is reinforced by stable carbon and nitrogen isotope values obtained from the mammoth remains. The endpoint of mammoth survival in the Pribilofs is unknown, but maybe coterminous with the arrival of polar bears whose remains in the cave date to the Neoglacial cold period of ~ 4500 to 3500 14C yr BP. The polar bear record corroborates a widespread cooling of the Bering Sea region at that time.

  13. Comprehensive geophysical prediction and treatment measures of karst caves in deep buried tunnel

    NASA Astrophysics Data System (ADS)

    Li, S. C.; Zhou, Z. Q.; Ye, Z. H.; Li, L. P.; Zhang, Q. Q.; Xu, Z. H.

    2015-05-01

    While tunneling in karst terrains, engineers may encounter hazardous geotechnical structures such as faults, karst caves and collapse columns which may induce geohazards and seriously endanger the construction safety. Geological processes significantly affect the varieties and characteristics of karst caves, and therefore engineering geological and hydrogeological conditions of Shangjiawan Tunnel were analyzed firstly. In order to accurately predict the geometric characteristics of karst caves and their spatial relationship with the tunnel, the Ground Penetrating Radar (GPR) and Geological Drilling (Geo-D) were applied comprehensively in the present study. The Tunnel Seismic Prediction (TSP) system was also applied to forecast whether any karst cave existed in front of the tunnel face and the detection results generally agree well with the field investigation. Furthermore, the Beam-Slab method was carried out for the treatment of the karst cave which situated under the tunnel floor, while the Backfill method was applied for the karst cave which was exposed during the construction.

  14. A diverse intrinsic antibiotic resistome from a cave bacterium

    PubMed Central

    Pawlowski, Andrew C.; Wang, Wenliang; Koteva, Kalinka; Barton, Hazel A.; McArthur, Andrew G.; Wright, Gerard D.

    2016-01-01

    Antibiotic resistance is ancient and widespread in environmental bacteria. These are therefore reservoirs of resistance elements and reflective of the natural history of antibiotics and resistance. In a previous study, we discovered that multi-drug resistance is common in bacteria isolated from Lechuguilla Cave, an underground ecosystem that has been isolated from the surface for over 4 Myr. Here we use whole-genome sequencing, functional genomics and biochemical assays to reveal the intrinsic resistome of Paenibacillus sp. LC231, a cave bacterial isolate that is resistant to most clinically used antibiotics. We systematically link resistance phenotype to genotype and in doing so, identify 18 chromosomal resistance elements, including five determinants without characterized homologues and three mechanisms not previously shown to be involved in antibiotic resistance. A resistome comparison across related surface Paenibacillus affirms the conservation of resistance over millions of years and establishes the longevity of these genes in this genus. PMID:27929110

  15. Karst and Caves in Post orogenetic carbonate breccias in Croatia

    NASA Astrophysics Data System (ADS)

    Garasic, M.

    2009-04-01

    In Croatian karst area there are several places where post orogenetic carbonate breccias are present. Coarse carbonate clastics of Lika, Velebit, Mala Kapela and Hrvatsko Primorje were first considered and described as a facies of the Paleogene Promina beds. However, because of their indistinct relation or sporadically mutual connections as well as the great difference in composition, were the reasons for the introduction of the term «Jelar beds». Their genesis is later connected with significant tectonic disturbances (inverse faulting and overthrusting), followed by younger predominantly vertical faults. Promina beds found in Ravni Kotari and Mt. Promina area, as well as Jelar bed areas, are at all times in transgressive contact with older beds (carbonate clastics estimated to date from Palaeogene -Neogene). Karstification in these beds is very intensive. Additionally, spring of river Gacka (length of third sinking river in the World), is situated in Jelar beds area, and river Zrmanja is partly breaking through Promina beds. Jelar carbonate breccias is present in Northern and Southern Velebit mountain. Maybe their genesis is connected with glaciation too, but the most important is that these rocks are very soluble. In an area of approx. 25 km2 on North Velebit Mt. more than 400 caves were discovered and explored. The systems Lukina jama - Trojama (-1392 m), Slovacka jama (-1301 m) and Velebita - Dva javora (-1026 m) are the deepest caves in Croatia. Furthermore, significant depth was reached at Meduza (-679 m), Patkov gust (-553 m), Ledena jama (-536 m) and Jama Olimp (-531 m). Theses caves are really vertical and inner vertical step in Valeria (518 me) is the deepest in the World, and outer vertical step in Patkov Gust (553 me) is the second vertical entrance in the World. All these caves are located in post or carbonate Jelar breccias. In an area of approx 30 km2 on South Velebit Mt. There are more than 300 caves discovered and explored. Well known Cerova

  16. Cave-soils, the soils forming underneath the surface

    NASA Astrophysics Data System (ADS)

    Dobos, Endre; Bertóti, Diána; Kovács, Károly; Vadnai, Péter

    2015-04-01

    Limestone cave sediments of the Bükk-mountain in the North-Eastern part of Hungary were described, analysed and classified using WRB soil classification system. Cave sediments can be considered as soils, partly on the basis of their origin, partly of processes taking place in them. Based on the results, it can be concluded that cave soils are often shallow, lying directly above the continuous rock. In general they are layered, with clearly distinct layers of alluvial origin. Their organic matter content depends on the nature of the sediment. They often contain considerable quantities of undecomposed organic sediment, acting as the basis for very intensive soil life, which can be detected in the soil structure and may in some cases result in Vermic characteristics. The texture is very variable, ranging from clay to rough gravelly sand. Almost 100% of the soils are calcareous, the lime content is of secondary origin and its amount is at least 2%. Therefore, the pH values fluctuate from neutral to 8.5, mostly having a value around 8. In rare cases gley formation also occurs, especially on poorly drained areas, where there is no water flow to refresh the dissolved oxygen content. In the "oxy-aquic" state, characterized by high dissolved oxygen content, the iron is not reduced, so gley formation is not induced. From pedological point of view, cave sediments show a very diverse picture. Besides sedimentary layers, numerous soil formation processes can be detected, which can be considered analogue with surface processes, therefore they definitely need to be classified as soils. According to all these, in the Hungarian classification cave soils are primarily classified as alluvial, colluvial or lithomorphic soils. The WRB classification places them mainly in the Fluvisol and Leptosol Reference Groups, and according to the soils examined in the present work, they can be described with the Leptic (Epileptic), Fluvic (in rare cases Colluvic), Vermic, Calcaric, Eutric, Gleyic

  17. [Progress on the degeneration mechanism of cave fishes' eyes].

    PubMed

    Gu, Xian; Ning, Tiao; Xiao, Heng

    2012-08-01

    Attempts to understand the degeneration of the eyes in cave fish has largely been explained by either various extents of gradual degeneration, ranging from partial to total loss, observed in various species or by acceleration of loss caused by dark environments. However, neither the theory of biological evolution developed by Charles Darwin nor the neutral theory of molecular evolution formulated by Kimura Motoo adequately explains these phenomena. Recent trends in utilizing multidisciplinary research, however, have yielded better results, helping reveal a more complex picture of the mechanisms of degeneration. Here, we summarize the current progress of the research via morphology and anatomy, development biology, animal behavior science and molecular genetics, and offer some perspectives on the ongoing research into the development and degeneration of eyes in cave fish.

  18. Phylogenetic diversity of culturable fungi in the Heshang Cave, central China

    PubMed Central

    Man, Baiying; Wang, Hongmei; Xiang, Xing; Wang, Ruicheng; Yun, Yuan; Gong, Linfeng

    2015-01-01

    Caves are nutrient-limited and dark subterranean ecosystems. To date, attention has been focused on geological research of caves in China, whilst indigenous microbial diversity has been insufficiently characterized. Here, we report the fungal diversity in the pristine, oligotrophic, karst Heshang Cave, central China, using a culture-dependent method coupled with the analysis of the fungal rRNA-ITS gene sequences. A total of 194 isolates were obtained with six different media from 14 sampling sites of sediments, weathered rocks, and bat guanos. Phylogenetic analysis clustered the 194 sequenced isolates into 33 genera within 15 orders of three phyla, Ascomycota, Basidiomycota, and Zygomycota, indicating a high degree of fungal diversity in the Heshang Cave. Notably, 16 out of the 36 fungal genera were also frequently observed in solution caves around the world and 23 genera were previously found in carbonate cave, indicating potential similarities among fungal communities in cave ecosystems. However, 10 genera in this study were not reported previously in any solution caves, thus expanding our knowledge about fungal diversity in cave ecosystems. Moreover, culturable fungal diversity varied from one habitat to another within the cave, being the highest in sediments, followed by weathered rocks and bat guanos as indicated by α-diversity indexes. At the genus level, Penicillium accounted for 40, 54, and 52% in three habitats of sediments, weathered rocks, and bat guanos, respectively. Trichoderma, Paecilomyces, and Aspergillus accounted for 9, 22, and 37% in the above habitats, correspondingly. Despite of the dominance of Penicillium in all samples, β-diversity index indicated significant differences between each two fungal communities in the three habitats in view of both the composition and abundance. Our study is the first report on fungal communities in a natural pristine solution cave system in central China and sheds light on fungal diversity and functions in

  19. Phylogenetic diversity of culturable fungi in the Heshang Cave, central China.

    PubMed

    Man, Baiying; Wang, Hongmei; Xiang, Xing; Wang, Ruicheng; Yun, Yuan; Gong, Linfeng

    2015-01-01

    Caves are nutrient-limited and dark subterranean ecosystems. To date, attention has been focused on geological research of caves in China, whilst indigenous microbial diversity has been insufficiently characterized. Here, we report the fungal diversity in the pristine, oligotrophic, karst Heshang Cave, central China, using a culture-dependent method coupled with the analysis of the fungal rRNA-ITS gene sequences. A total of 194 isolates were obtained with six different media from 14 sampling sites of sediments, weathered rocks, and bat guanos. Phylogenetic analysis clustered the 194 sequenced isolates into 33 genera within 15 orders of three phyla, Ascomycota, Basidiomycota, and Zygomycota, indicating a high degree of fungal diversity in the Heshang Cave. Notably, 16 out of the 36 fungal genera were also frequently observed in solution caves around the world and 23 genera were previously found in carbonate cave, indicating potential similarities among fungal communities in cave ecosystems. However, 10 genera in this study were not reported previously in any solution caves, thus expanding our knowledge about fungal diversity in cave ecosystems. Moreover, culturable fungal diversity varied from one habitat to another within the cave, being the highest in sediments, followed by weathered rocks and bat guanos as indicated by α-diversity indexes. At the genus level, Penicillium accounted for 40, 54, and 52% in three habitats of sediments, weathered rocks, and bat guanos, respectively. Trichoderma, Paecilomyces, and Aspergillus accounted for 9, 22, and 37% in the above habitats, correspondingly. Despite of the dominance of Penicillium in all samples, β-diversity index indicated significant differences between each two fungal communities in the three habitats in view of both the composition and abundance. Our study is the first report on fungal communities in a natural pristine solution cave system in central China and sheds light on fungal diversity and functions in

  20. Effect of diurnal and seasonal temperature variation on Cussac cave ventilation using co2 assessment

    NASA Astrophysics Data System (ADS)

    Peyraube, Nicolas; Lastennet, Roland; Villanueva, Jessica Denila; Houillon, Nicolas; Malaurent, Philippe; Denis, Alain

    2016-05-01

    Cussac cave was investigated to assess the cave air temperature variations and to understand its ventilation regime. This cave is located in an active karst system in the south west part of France. It has a single entrance and is considered as a cold air trap. In this study, air mass exchanges were probed. Measurements of temperature and Pco2 with a 30-min frequency were made in several locations close to the cave entrance. Speed of the air flow was also measured at the door of cave entrance. Results show that cave air Pco2 varies from 0.18 to 3.33 %. This cave appears to be a CO2 source with a net mass of 2319 tons blown in 2009. Carbon-stable isotope of CO2 (13Cco2) ranges from -20.6 ‰ in cold season to -23.8 ‰ in warm season. Cave air is interpreted as a result of a mix between external air and an isotopically depleted air, coming from the rock environment. The isotopic value of the light member varies through time, from -23.9 to -22.5 ‰. Furthermore, this study ascertains that the cave never stops in communicating with the external air. The ventilation regime is identified. (1) In cold season, the cave inhales at night and blows a little at the warmest hours. However, in warm season, (2) cave blows at night, but (3) during the day, a convection loop takes place in the entrance area and prevents the external air from entering the cave, confirming the cold air trap.

  1. Touchdown Ball-Bearing System for Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Kingsbury, Edward P.; Price, Robert; Gelotte, Erik; Singer, Herbert B.

    2003-01-01

    The torque-limited touchdown bearing system (TLTBS) is a backup mechanical-bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in steady-state normal operation. The TLTBS provides ball-bearing support to augment or supplant the magnetic bearings during startup, shutdown, or failure of the magnetic bearings. The TLTBS also provides support in the presence of conditions (in particular, rotational acceleration) that make it difficult or impossible to control the magnetic bearings or in which the magnetic bearings are not strong enough (e.g., when the side load against the rotor exceeds the available lateral magnetic force).

  2. Top coal caving longwall maximizes thick seam recovery

    SciTech Connect

    Duncan, G.; Sobey,. G.; Clarke, T.

    2007-07-15

    Austar's longwall system offers opportunities in coal seams thicker than 4.5 meters. The Longwall Top Coal Caving (LTCC) method was recently launched in Australia at Yancoal Australia's Austar mines in Hunter Valley, although 90 such longwalls already operate in China. The article describes the method and its installation at Austar. In September 2006 the LTCC face commenced production. The operation is described and measures to prevent spontaneous combustion are outlined. Future work on the longwall is mentioned. 11 figs.

  3. Post-speleogenetic biogenic modification of Gomantong Caves, Sabah, Borneo

    NASA Astrophysics Data System (ADS)

    Lundberg, Joyce; McFarlane, Donald A.

    2012-07-01

    The Gomantong cave system of eastern Sabah, Malaysia, is well-known as an important site for harvesting edible bird-nests and, more recently, as a tourist attraction. Although the biology of the Gomantong system has been repeatedly studied, very little attention has been given to the geomorphology. Here, we report on the impact of geobiological modification in the development of the modern aspect of the cave, an important but little recognized feature of tropical caves. Basic modeling of the metabolic outputs from bats and birds (CO2, H2O, heat) reveals that post-speleogenetic biogenic corrosion can erode bedrock by between ~ 3.0 mm/ka (1 m/~300 ka) and ~ 4.6 mm/ka (1 m/~200 ka). Modeling at high densities of bats yields rates of corrosion of ~ 34 mm/ka (or 1 m/~30 ka). Sub-aerial corrosion creates a previously undescribed speleological feature, the apse-flute, which is semicircular in cross-section and ~ 80 cm wide. It is vertical regardless of rock properties, developing in parallel but apparently completely independently, and often unbroken from roof to floor. They end at a blind hemi-spherical top with no extraneous water source. Half-dome ceiling conch pockets are remnants of previous apse-fluting. Sub-cutaneous corrosion creates the floor-level guano notch formed by organic acid dissolution of bedrock in contact with guano. Speleogenetic assessment suggests that as much as 70-95% of the total volume of the modern cave may have been opened by direct subaerial biogenic dissolution and biogenically-induced collapse, and by sub-cutaneous removal of limestone, over a timescale of 1-2 Ma.

  4. Epidermoid tumor within Meckel's cave--case report.

    PubMed

    Nadkarni, T; Dindorkar, K; Muzumdar, D; Goel, A

    2000-01-01

    A rare case of an epidermoid tumor lying within Meckel's cave is reported. A 27-year-old housewife presented with complaints of right facial hypesthesia for two and a half years. On examination she had partial loss of touch sensation in the right trigeminal nerve distribution. Magnetic resonance imaging revealed a tumor located at the right petrous apex and cavernous sinus. The epidermoid tumor was excised through a lateral basal subtemporal approach. The symptoms resolved following surgery.

  5. Tuberculoma in the Meckel's cave: a case report.

    PubMed

    Goel, A; Nadkarni, T; Desai, A P

    1999-09-01

    A case of an intracranial tuberculoma located within the confines of the Meckel's cave is presented. The patient was young, non-immunocompromised and otherwise in good health. The granuloma mingled with the fibres of the trigeminal nerve. The lesion mimicked a trigeminal neurinoma in its clinical presentation, preoperative investigations and intraoperative consistency and vascularity. The rarity of the location and possible mode of transmission of infection to this site is discussed. The literature on this subject is briefly reviewed.

  6. HTS magnetic bearings

    NASA Astrophysics Data System (ADS)

    Werfel, Frank N.; Flögel-Delor, Uta; Rothfeld, Rolf; Wippich, Dieter; Riedel, Thomas

    2002-08-01

    Radial HTS magnetic bearings (SMB) up to 200 mm size are developed and tested in prototype fast rotating machines to demonstrate the potential to replace conventional bearings. The individual rotational bearing components HTS and PM, their physical interaction and technology is reviewed. Characterisation experiments are conducted to understand the rotor dynamic behaviour. In terms of unbalance and critical speeds the suspended wheels and rotors compare favourably with conventional bearing devices. The rationale of our present bearing technology lies in the assembling of both low-speed magnetic bearings for centrifugal and wafer processing units up to 20,000 rpm as well as a high-speed optical mirror accelerated to rim speed of more than 500 m/s (174,000 rpm) confirming stable low-drag and low energy operation. Two new-type U shaped semicircle HTS bearings coupled each with a 6 W/80 K cryocooler of the Stirling type allow the contact-free operation of a Si wafer carrier in semiconductor wet processes.

  7. Statistical Analysis of Resistivity Anomalies Caused by Underground Caves

    NASA Astrophysics Data System (ADS)

    Frid, V.; Averbach, A.; Frid, M.; Dudkinski, D.; Liskevich, G.

    2017-03-01

    Geophysical prospecting of underground caves being performed on a construction site is often still a challenging procedure. Estimation of a likelihood level of an anomaly found is frequently a mandatory requirement of a project principal due to necessity of risk/safety assessment. However, the methodology of such estimation is not hitherto developed. Aiming to put forward such a methodology the present study (being performed as a part of an underground caves mapping prior to the land development on the site area) consisted of application of electrical resistivity tomography (ERT) together with statistical analysis utilized for the likelihood assessment of underground anomalies located. The methodology was first verified via a synthetic modeling technique and applied to the in situ collected ERT data and then crossed referenced with intrusive investigations (excavation and drilling) for the data verification. The drilling/excavation results showed that the proper discovering of underground caves can be done if anomaly probability level is not lower than 90 %. Such a probability value was shown to be consistent with the modeling results. More than 30 underground cavities were discovered on the site utilizing the methodology.

  8. Measuring Light Air Ions in a Speleotherapeutic Cave

    NASA Astrophysics Data System (ADS)

    Roubal, Z.; Bartušek, K.; Szabó, Z.; Drexler, P.; Überhuberová, J.

    2017-02-01

    The paper deals with a methodology proposed for measuring the concentration of air ions in the environment of speleotherapeutic caves, and with the implementation of the AK-UTEE-v2 ionmeter. Speleotherapy, in the context of its general definition, is the medical therapy that utilizes the climate of selected caves to treat patients with health problems such as asthma. These spaces are characterized by the presence of high air humidity and they make extreme demands on the execution of the measuring device, the Gerdien tube (GT in the following) in particular, and on the amplifier electronics. The result is an automated measuring system using a GT with low-volume air flow, enabling long-term measuring of air ion concentration and determination of spectral ion characteristics. Interesting from the instrumentation viewpoint are the GT design, active shielding, and execution of the electrometric amplifier. A specific method for the calculation of spectral ion characteristics and the mode of automatic calibration were proposed and a procedure of automatic measurement in the absence of attendants was set up. The measuring system is designed for studying and long-term monitoring of the concentration of light negative ions in dependence on climatic conditions and on the mobility of ions occurring in the cave.

  9. Differential effects of distinct bacterial biofilms in a cave environment.

    PubMed

    Portillo, Maria C; Gonzalez, Juan M

    2010-06-01

    Current microbial surveys using molecular methods provide us with critical information on the major components of natural bacterial communities. However, limited investigation has been performed on the influence of bacterial metabolism on the environment. In this study, we analyzed the pH generated by distinct bacterial communities in a cave environment. Different bacterial biofilms developing on the walls of the cave were visually distinguished by their colorations (e.g., white, yellow, and gray) and mineral depositions, and previous studies have reported on their bacterial diversity and distribution. Using pH microelectrodes, we carried out in situ measurements and were able to detect differences among these bacterial biofilms. White biofilms and carbonate depositions resulted in alkaline pH values. Gray biofilms also increased the pH although these values remained lower than in white biofilms. A combination of gray-white biofilms resulted in alkaline pH values with highest values at the white edge of the colonies. Yellow biofilms generated a slightly acid pH. These results suggest that different bacterial communities can lead to distinct effects on their environment, for instance, precipitation or dissolution of carbonates in caves. These results add information about metabolic response to current knowledge from bacterial diversity surveys, providing information on the interaction between complex bacterial communities and the geological substrate.

  10. Lesions in Meckel's cave: variable presentation and pathology.

    PubMed

    Beck, D W; Menezes, A H

    1987-11-01

    A series of 12 patients with mass lesions arising from Meckel's cave is presented. Patients' age on presentation ranged from 13 months to 71 years. Nine of the 12 patients had symptoms referable to the fifth cranial nerve, but only three complained of facial pain. The 12 patients presented eight different pathological entities, including meningioma, lipoma, schwannoma, malignant melanotic schwannoma, arachnoid cyst, neurofibroma, epidermoid tumor, and chordoma. Computerized tomography and magnetic resonance imaging were most useful in localizing the lesion to Meckel's cave. All 12 patients underwent a subtemporal approach to the lesion, and gross total removal was achieved in 11. Postoperative results were excellent with no increased neurological deficits seen 3 months postoperatively. Most patients had resolution of the cranial nerve deficits except for fifth nerve function, which was impaired in nine patients postoperatively. This series demonstrates that lesions in Meckel's cave can have a varied and unusual presentation, as well as an assortment of pathology. Total removal of lesions in this area resulted in relief of symptoms in most patients, with minimum morbidity.

  11. Ball and Roller Bearings. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The manual provides a subject reference for ball and roller bearings. The following topics are included: (1) bearing nomenclature, (2) bearing uses, (3) bearing capacities, (4) shop area working conditions, (5) bearing removal, (6) bearing cleaning and inspection, (7) bearing replacement, (8) bearing lubrication, (9) bearing installation, (10)…

  12. Occurrence of organic wastewater and other contaminants in cave streams in northeastern Oklahoma and northwestern Arkansas

    USGS Publications Warehouse

    Bidwell, Joseph R.; Becker, C.; Hensley, S.; Stark, R.; Meyer, M.T.

    2010-01-01

    The prevalence of organic wastewater compounds in surface waters of the United States has been reported in a number of recent studies. In karstic areas, surface contaminants might be transported to groundwater and, ultimately, cave ecosystems, where they might impact resident biota. In this study, polar organic chemical integrative samplers (POCISs) and semipermeable membrane devices (SPMDs) were deployed in six caves and two surface-water sites located within the Ozark Plateau of northeastern Oklahoma and northwestern Arkansas in order to detect potential chemical contaminants in these systems. All caves sampled were known to contain populations of the threatened Ozark cavefish (Amblyopsis rosae). The surface-water site in Oklahoma was downstream from the outfall of a municipal wastewater treatment plant and a previous study indicated a hydrologic link between this stream and one of the caves. A total of 83 chemicals were detected in the POCIS and SPMD extracts from the surface-water and cave sites. Of these, 55 chemicals were detected in the caves. Regardless of the sampler used, more compounds were detected in the Oklahoma surface-water site than in the Arkansas site or the caves. The organic wastewater chemicals with the greatest mass measured in the sampler extracts included sterols (cholesterol and ??-sitosterol), plasticizers [diethylhexylphthalate and tris (2-butoxyethyl) phosphate], the herbicide bromacil, and the fragrance indole. Sampler extracts from most of the cave sites did not contain many wastewater contaminants, although extracts from samplers in the Oklahoma surfacewater site and the cave hydrologically linked to it had similar levels of diethylhexyphthalate and common detections of carbamazapine, sulfamethoxazole, benzophenone, N-diethyl-3-methylbenzamide (DEET), and octophenol monoethoxylate. Further evaluation of this system is warranted due to potential ongoing transport of wastewaterassociated chemicals into the cave. Halogenated organics

  13. A global model for cave ventilation and seasonal bias in speleothem paleoclimate records

    NASA Astrophysics Data System (ADS)

    James, Eric W.; Banner, Jay L.; Hardt, Benjamin

    2015-04-01

    Cave calcite deposits (speleothems) provide long and continuous records of paleoenvironmental conditions in terrestrial settings. Typical environmental proxy measurements include speleothem growth rate and variations in elemental and isotope geochemistry. Commonly the assumption is made that speleothems grow continuously and at a constant rate throughout the year. However, seasonal variation of growth rate may be the rule in many caves. Here we apply observations of modern calcite growth and cave-air CO2 concentrations and a model of factors controlling cave ventilation to construct a global model predicting where cave calcite growth may be seasonal. Previous models and measurements of calcite precipitation in caves demonstrate the retardation of speleothem growth by high cave-air CO2. Elevated CO2 is commonly dissipated by ventilation driven by density differences between cave and surface air. Seasonal cycles in atmospheric temperature, pressure, and humidity commonly drive these density contrasts. Modeling these changes latitudinally and globally indicates a geographic control on seasonal cave ventilation and thus on a principal controlling factor of speleothem growth. The model predicts that given constant water, calcium, and CO2 inputs, speleothems from temperate to boreal continental regions commonly accumulate more calcite in the cool season and less or none in the warm season. These models predict that proxies from temperate to boreal speleothems may be seasonally biased due to seasonal ventilation, whereas tropical and maritime records should not.

  14. Environmental drivers of phototrophic biofilms in an Alpine show cave (SW-Italian Alps).

    PubMed

    Piano, E; Bona, F; Falasco, E; La Morgia, V; Badino, G; Isaia, M

    2015-12-01

    The proliferation of lampenflora is a major threat for the conservation of show caves, since phototrophic organisms cause physical, chemical and aesthetic damage to speleothems. In this paper we examine the environmental factors influencing the presence and the growth of the three main photosynthetic groups composing phototrophic biofilms in the Bossea show cave (SW-Italian Alps). The presence and the primary production of cyanobacteria, diatoms and green algae were detected with BenthoTorch®, an instrument for in situ measurement of chlorophyll a concentration that has never been used before in caves. By means of different techniques of regression analysis, we highlighted the response of the three photosynthetic groups to different environmental factors. Illuminance proved to be the main factor influencing positively both the probability of the presence and the productivity of the three groups. The presence of seeping water on the substrate and the distance from the cave entrance proved to play an important role in determining patterns of colonization. By means of GIS techniques, we provide thematic maps of the cave, providing a representation of pattern of the density of the three examined photosynthetic groups within different areas of the cave. The same approach may apply to other show caves, aiming at providing suggestions for the cave management (i.e. cleaning of the cave walls and positioning of artificial lights) and reduce impact caused by tourism.

  15. A spider species complex revealed high cryptic diversity in South China caves.

    PubMed

    Zhang, Yuanyuan; Li, Shuqiang

    2014-10-01

    Cryptic species, which are an important component of biodiversity, have rarely been studied in South China karst. We investigated cryptic diversity in the cave species complex Telema cucurbitina, which has a narrow niche but widespread distribution among multiple caves. We sampled another 15 populations (caves) in addition to the population from the type locality. Phylogenetic results indicated that individuals from the same cave constituted well-supported clades. Species diversity within this species complex was assessed in a coalescent framework, first with a Bayesian extension of the general mixed Yule coalescent (bGMYC) model and a Bayesian species delimitation method (BPP). Both species delimitation methods identified each cave population as a separate species. We propose that each cave population within this species complex was a separate evolving lineage and therefore 16 OTUs were recovered based on our molecular data despite their high morphological similarities. We also propose that the unrecognized organism's diversity within South China caves might be extremely large considering our case. Furthermore, our work reveals that species discovery of cave organisms by morphological data has a high probability of underestimating hidden diversity. Our work also highlights the need for conservation strategies to protect this largely neglected diversity of cave organisms.

  16. Evolution of the optical releasers for aggressive behavior in cave-dwelling Astyanax fasciatus (Teleostei, Characidae).

    PubMed

    Langecker, T G; Neumann, B; Hausberg, C; Parzefall, J

    1995-07-01

    Epigean and blind cave-dwelling populations of the characid Astyanax fasciatus differ in their agonistic behavior. Epigean specimens are characterized by intense aggressive behavior and territoriality in the laboratory, whereas the blind cave fishes are rarely aggressive and have totally lost the territorial behavior. These behavioral changes are genetically based. In the present study, a comparative analysis of the optical releasers for aggressive behavior has been performed in both epigean and cave-dwelling populations. It was expected that the regression of aggressive behavior should be accompanied by the regression of the genetically fixed optical releasers for aggression in the cave specimens. For the analysis of cave fishes, well-eyed F1-hybrids of cave and epigean specimens (Pachon × Teapao) as well as phylogenetically young cave specimens (Micos) selected for large eyes, have been used. In epigean specimens, aggression is most intensely released by a combination of the signals 'natural shape' and 'locomotion'. The cave populations exhibit a partial regression of the releaser 'natural shape'. 'Locomotion', however, has become a more effective releaser for aggression in cave fishes than it has in their epigean relatives. The results are discussed with respect to their evolutionary significance.

  17. Occurrence of organic wastewater and other contaminants in cave streams in northeastern Oklahoma and northwestern Arkansas.

    PubMed

    Bidwell, Joseph R; Becker, Carol; Hensley, Steve; Stark, Richard; Meyer, Michael T

    2010-02-01

    The prevalence of organic wastewater compounds in surface waters of the United States has been reported in a number of recent studies. In karstic areas, surface contaminants might be transported to groundwater and, ultimately, cave ecosystems, where they might impact resident biota. In this study, polar organic chemical integrative samplers (POCISs) and semipermeable membrane devices (SPMDs) were deployed in six caves and two surface-water sites located within the Ozark Plateau of northeastern Oklahoma and northwestern Arkansas in order to detect potential chemical contaminants in these systems. All caves sampled were known to contain populations of the threatened Ozark cavefish (Amblyopsis rosae). The surface-water site in Oklahoma was downstream from the outfall of a municipal wastewater treatment plant and a previous study indicated a hydrologic link between this stream and one of the caves. A total of 83 chemicals were detected in the POCIS and SPMD extracts from the surface-water and cave sites. Of these, 55 chemicals were detected in the caves. Regardless of the sampler used, more compounds were detected in the Oklahoma surface-water site than in the Arkansas site or the caves. The organic wastewater chemicals with the greatest mass measured in the sampler extracts included sterols (cholesterol and beta-sitosterol), plasticizers [diethylhexylphthalate and tris(2-butoxyethyl) phosphate], the herbicide bromacil, and the fragrance indole. Sampler extracts from most of the cave sites did not contain many wastewater contaminants, although extracts from samplers in the Oklahoma surface-water site and the cave hydrologically linked to it had similar levels of diethylhexyphthalate and common detections of carbamazapine, sulfamethoxazole, benzophenone, N-diethyl-3-methylbenzamide (DEET), and octophenol monoethoxylate. Further evaluation of this system is warranted due to potential ongoing transport of wastewater-associated chemicals into the cave. Halogenated organics

  18. Ball Bearing Mechanics

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    Load-deflection relationships for different types of elliptical contacts such as those found in a ball bearing are developed. Simplified expressions that allow quick calculations of deformation to be made simply from a knowledge of the applied load, the material properties, and the geometry of the contacting elements are presented. Ball bearings subjected to radial, thrust and combined ball loads are analyzed. A design criterion for fatigue life of ball bearings is developed. The section of a satisfactory lubricant, as well as describing systems that provide a constant flow of lubricant to the contact, is considered.

  19. Subaerial freshwater phosphatic stromatolites in Deer Cave, Sarawak — A unique geobiological cave formation

    NASA Astrophysics Data System (ADS)

    Lundberg, Joyce; McFarlane, Donald A.

    2011-05-01

    A suite of distinctive freshwater subaerial phosphatic stromatolites is developed close to the northeastern entrance of Deer Cave, Gunung Mulu National Park, Sarawak, Borneo, in conditions of very low light but ample supply of nutrients from guano. These stromatolites are not particulate; they are composed of alternating layers of more porous and more dense amorphous hydroxylapatite. This biomineralization occurs as moulds of coccoid (the majority) and filamentous (less abundant) cyanobacteria. Mineralization occurs at a pH of ~ 7.0 in the extracellular sheaths and in micro-domains of varying carbonate content in the surrounding mucus of the biofilm. The most recent surfaces that are not yet strongly mineralized show still-living filamentous, coccoid and rod-shaped forms. Trace element composition shows enrichment in metal ions, especially Mn and Zn. The stromatolites are present as horizontal shelves arranged in series on a steep rock face that is vertically under a guano-laden shelf. The rock face undergoes active dissolution from acidic guano drainage water (e.g., pH of 2.43) and from aggressive rainwater from an overhead discharge. However, the rock surface under the stromatolite is protected while the rest of the cliff face is backcut, creating a hoodoo-like effect. The stromatolites are ~ 15-20 cm deep, ~ 4-7 cm thick, and of variable width, generally ~ 50 cm. Eventually, guano and biological detritus in the descending water film lodge in the lee of the stromatolite lip, causing local acidification and erosion of stromatolite and rock on the underside of the ledge. A dynamic equilibrium is established between upward accretion of the fresh surface and destruction at the base such that the base of the stromatolite does not reflect the date of its inception and the stromatolite climbs up the wall.

  20. Arkansas black bear hunter survey

    USGS Publications Warehouse

    Pharris, Larry D.; Clark, Joseph D.

    1987-01-01

    Questionnaires were mailed to black bear (Ursus americanus) hunters in Arkansas following the 1980-84 bear seasons to determine participation, hunter success, and number of bears observed by hunters. Man-days of hunting to harvest a bear ranged from 148 to 671 and hunter success ranged from 0.4% to 2.2%. With the exception of 1980, number of permits issued, man-days of bear hunting, and bears harvested appear affected by hunting permit cost. 

  1. Application of a cave inventory system to stimulate development of management strategies: the case of west-central Florida, USA.

    PubMed

    Harley, Grant L; Polk, Jason S; North, Leslie A; Reeder, Philip P

    2011-10-01

    The active management of air-filled cave systems is virtually non-existent within the karst landscape of west-central Florida. As in every karst landscape, caves are important because they contain a wide variety of resources (e.g., biota, speleothems) and can act as direct connections between surface and subsurface hydrological processes, potentially exacerbating the pollution of groundwater. Before sound management policies can be drafted, implemented, and enforced, stakeholders must first have knowledge of the management requirements of each cave. However, there is an informational disconnect between researchers, stakeholders, and the recreational caving community. Here, we present a cave inventory system that simplifies the dissemination of resource knowledge to stakeholders so that cave management and protection policies can be drafted and implemented at the state and local level. We inventoried 36 caves in west-central Florida, located on both public and private land, and analyzed cave resource data to provide insights on cave sensitivity and disturbance using two standardized indices. The data revealed that both public and private caves exhibit a wide range of sensitivity and disturbance, and before management strategies can be drafted, the ownership of each cave must be considered. Our inventory geodatabase serves as a link between researchers, landowners, and the public. To ensure the conservation and protection of caves, support from county or state government, combined with cave inventory data, is crucial in developing sound management policy.

  2. Phototrophic microorganisms in biofilm samples from Vernjika Cave, Serbia

    NASA Astrophysics Data System (ADS)

    Popović, Slađana; Jovanović, Jelena; Predojević, Dragana; Trbojević, Ivana; Blagojević, Ana; Subakov Simić, Gordana

    2016-04-01

    Caves represent specific natural monuments in terms of structure, complexity and beauty which can be found worldwide. Even though they are considered extreme environments, they are still a unique habitat for a large number of organisms that grow and proliferate here. Often can be seen that the cave walls are differently coloured as a consequence of the biofilm development. Biofilms represent complex communities of microorganisms that can develop on different kind of surfaces, including various rock surfaces. Each microbe species play a different role in a community, but their development on stone surfaces can cause substantial damage to the substrates through different mechanisms of biodeterioration and degradation. There is an increased interest in the phototrophic component of biofilms (aerophytic cyanobacteria and algae), especially cyanobacteria, an ancient microorganisms capable to survive the most diverse extreme conditions. These phototrophs can easily be found at cave entrances illuminated by direct or indirect sunlight and areas near artificial lights. Cyanobacteria and algae were investigated in biofilm samples taken from the entrance of Vernjika Cave in Eastern Serbia. Cyanobacteria, Chlorophyta and Bacillariophyta were documented, with Cyanobacteria as a group with the highest number of recorded taxa. Chroococcalean species were the most diverse with the most frequently encountered species from the genus Gloeocapsa. Phormidium and Nostoc species were commonly recorded Oscillatoriales and Nostocles, respectively. Among Oscillatoriales species, it was noticed that one Phormidium species precipitates CaCO3 on it's sheats. Trebouxia sp. and Desmococcus olivaceus were frequently documented Chlorophyta, and representatives of Bacillariophyta were exclusively aerophytic taxa, mostly belonging to the genera Luticola and Humidophila. Measured ecological parameters, temperature and relative humidity, were influenced by the external climatic changes, while light

  3. Roller bearing geometry design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Pinkston, B. H. W.

    1976-01-01

    A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

  4. Gear bearing drive

    NASA Technical Reports Server (NTRS)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  5. High speed hybrid bearing comprising a fluid bearing and a rolling bearing convected in series

    NASA Technical Reports Server (NTRS)

    Anderson, W. J. (Inventor)

    1973-01-01

    A description is given of an antifriction bearing and a process by which its fatigue life may be extended. The method involves a rotating shaft supported by a fluid bearing and a rolling element bearing coupled in series. Each bearing turns at a fraction of the rotational speed of the shaft. The fluid bearing is preferably conical, thereby providing thrust and radial load support in a single bearing structure.

  6. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A magnetic bearing for passively suspending a rotatable element subjected to axial and radial thrust forces is disclosed. The magnetic bearing employs a taut wire stretched along the longitudinal axis of the bearing between opposed end pieces and an intermediate magnetic section. The intermediate section is segmented to provide oppositely directed magnetic flux paths between the end pieces and may include either an axially polarized magnets interposed between the segments. The end pieces, separated from the intermediate section by air gaps, control distribution of magnetic flux between the intermediate section segments. Coaxial alignment of the end pieces with the intermediate section minimizes magnetic reluctance in the flux paths endowing the bearing with self-centering characteristics when subjected to radial loads. In an alternative embodiment, pairs of oppositely wound armature coils are concentrically interposed between segments of the intermediate section in concentric arcs adjacent to radially polarized magnets to equip a magnetic bearing as a torsion drive motor. The magnetic suspension bearing disclosed provides long term reliability without maintenance with application to long term space missions such as the VISSR/VAS scanning mirror instrument in the GOES program.

  7. Load responsive hydrodynamic bearing

    DOEpatents

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  8. Investigation of Pressurized Wave Bearings

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Dimofte, Florin

    2003-01-01

    The wave bearing has been pioneered and developed by Dr. Dimofte over the past several years. This bearing will be the main focus of this research. It is believed that the wave bearing offers a number of advantages over the foil bearing, which is the bearing that NASA is currently pursuing for turbomachinery applications. The wave bearing is basically a journal bearing whose film thickness varies around the circumference approximately sinusoidally, with usually 3 or 4 waves. Being a rigid geometry bearing, it provides precise control of shaft centerlines. The wave profile also provides good load capacity and makes the bearing very stable. Manufacturing techniques have been devised that should allow the production of wave bearings almost as cheaply as conventional full-circular bearings.

  9. Study of pulmonary functions of the tourist guides in two show caves in Slovenia

    NASA Astrophysics Data System (ADS)

    Debevec Gerjevic, V.; Jovanovič, P.

    2009-04-01

    Park Škocjan Caves is located in South Eastern part of Slovenia. It was established with aim of conserving and protecting exceptional geomorphological, geological and hydrological outstanding features, rare and endangered plant and animal species, paleontological and archaeological sites, ethnological and architectural characteristics and cultural landscape and for the purpose of ensuring opportunities for suitable development, by the National Assembly of the Republic of Slovenia in 1996. Due to their exceptional significance for cultural and natural heritage, the Škocjan Caves were entered on UNESCO's list of natural and cultural world heritage sites in 1986. Caves have always been special places for people all over the world. There has been a lot of research done in the field of speleology and also in medicine in relation to speleotherapy. There is still one field left partial unexplored and its main issue covers the interaction between special ecosystems as caves and human activities and living. Implementing the Slovene legislation in the field of radiation protection, we are obligated to perform special measurements in the caves and also having our guides and workers in the caves regularly examined according to established procedure. The medical exams are performed at Institution of Occupational Safety, Ljubljana in order to monitor the influence of Radon to the workers in the cave. The issue of epidemiologic research encompass several factors that are not necessarily related to the radon. Park Škocjan Caves established research monitoring projects such as caves microclimate parameters, quality of the water, every day's data from our meteorological station useful tool in public awareness related to pollution and climate change. Last year a special study was started in order to evaluate pulmonary functions of persons who work in the caves and those who work mostly in offices. Two groups of tourist guides from Škocjan Caves and Postojna Cave were included in

  10. Controls on cave drip water temperature and implications for speleothem-based paleoclimate reconstructions

    NASA Astrophysics Data System (ADS)

    Rau, Gabriel C.; Cuthbert, Mark O.; Andersen, Martin S.; Baker, Andy; Rutlidge, Helen; Markowska, Monika; Roshan, Hamid; Marjo, Christopher E.; Graham, Peter W.; Acworth, R. Ian

    2015-11-01

    While several studies explore cave climate and thermal regimes, little is known about the controls on cave drip water temperature. Yet water temperature significantly influences biogeochemical processes associated with cave drips. To identify the processes that control the cave drip water temperature, we measured the temperatures at multiple locations along a speleothem flow path and drip sources (stalactites) concurrently with the drip rates in Cathedral Cave, Wellington, Australia. We monitored long-term drip water temperature, drip rates, surface and cave climate and in-cave evaporation rates and conducted 3 infiltration experiments with different flow, temperature and isotopic conditions. Our results show that the drip water temperature is controlled by multiple superimposed heat transport mechanisms that act upon the infiltrating water in the epikarst, the water film after it enters the cave and before it becomes a drip. The two main heat sources/sinks for drip water are the cave air and the surrounding rock. The subsurface temperature is coupled to the surface temperature by conduction through the soil and rock mass, but the cave climate is also coupled to the surface climate by venting. On a regional scale, drip temperatures are mainly driven by the annual ground surface temperature signal but damped with depth and shifted in time compared to the surface. On a local scale, the drip water temperature can differ significantly from cave air and speleothem temperature due to the latent heat exchange of evaporation and localised water film convection. The main controls are ground surface temperature, subsurface depth, air density induced ventilation, distance from entry and drip rate. We present a conceptual model that explains drip water temperature signals and provide signal driven guidance on best type and location for speleothem sampling. We anticipate that our results will significantly improve the understanding of temperature-dependent paleoclimate signals

  11. Buthid scorpions found in caves; a new species of Isometrus Ehrenberg, 1828 (Scorpiones, Buthidae) from southern Vietnam.

    PubMed

    Lourenço, Wilson R; Duhem, Bernard

    2010-08-01

    A new species, Isometrus (Reddyanus) deharvengi sp. n., is described from caves of the region of Hon Chong, Kien Giang in southern Vietnam. Comments are also added about the scorpion fauna of Southeast Asia and cave dwelling buthid scorpions.

  12. Climate Drives Polar Bear Origins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  13. Phylogeography of Sardinian Cave Salamanders (Genus Hydromantes) Is Mainly Determined by Geomorphology

    PubMed Central

    Chiari, Ylenia; van der Meijden, Arie; Mucedda, Mauro; Lourenço, João M.; Hochkirch, Axel; Veith, Michael

    2012-01-01

    Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems. PMID:22427830

  14. Recognition of microclimate zones through radon mapping, Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    USGS Publications Warehouse

    Cunningham, K.I.; LaRock, E.J.

    1991-01-01

    Radon concentrations range from <185 to 3,515 Bq m-3 throughout Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico. Concentrations in the entrance passages and areas immediately adjacent to these passages are controlled by outside air temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.

  15. High endemism at cave entrances: a case study of spiders of the genus Uthina

    PubMed Central

    Yao, Zhiyuan; Dong, Tingting; Zheng, Guo; Fu, Jinzhong; Li, Shuqiang

    2016-01-01

    Endemism, which is typically high on islands and in caves, has rarely been studied in the cave entrance ecotone. We investigated the endemism of the spider genus Uthina at cave entrances. Totally 212 spiders were sampled from 46 localities, from Seychelles across Southeast Asia to Fiji. They mostly occur at cave entrances but occasionally appear at various epigean environments. Phylogenetic analysis of DNA sequence data from COI and 28S genes suggested that Uthina was grouped into 13 well-supported clades. We used three methods, the Bayesian Poisson Tree Processes (bPTP) model, the Bayesian Phylogenetics and Phylogeography (BPP) method, and the general mixed Yule coalescent (GMYC) model, to investigate species boundaries. Both bPTP and BPP identified the 13 clades as 13 separate species, while GMYC identified 19 species. Furthermore, our results revealed high endemism at cave entrances. Of the 13 provisional species, twelve (one known and eleven new) are endemic to one or a cluster of caves, and all of them occurred only at cave entrances except for one population of one species. The only widely distributed species, U. luzonica, mostly occurred in epigean environments while three populations were found at cave entrances. Additionally, eleven new species of the genus are described. PMID:27775081

  16. Phylogeography of Sardinian cave salamanders (genus Hydromantes) is mainly determined by geomorphology.

    PubMed

    Chiari, Ylenia; van der Meijden, Arie; Mucedda, Mauro; Lourenço, João M; Hochkirch, Axel; Veith, Michael

    2012-01-01

    Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems.

  17. Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda)

    PubMed Central

    Golovatch, Sergei; Wesener, Thomas; Tian, Mingyi

    2017-01-01

    Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life. PMID:28178274

  18. Metagenomic Analysis from the Interior of a Speleothem in Tjuv-Ante's Cave, Northern Sweden.

    PubMed

    Zepeda Mendoza, Marie Lisandra; Lundberg, Johannes; Ivarsson, Magnus; Campos, Paula; Nylander, Johan A A; Sallstedt, Therese; Dalen, Love

    2016-01-01

    Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante's cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante's cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i) an evaluation of the use of these speleothems as past biodiversity archives, ii) functional and taxonomic profiling of the speleothem's different formation periods, and iii) taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching.

  19. Recognition of microclimate zones through radon mapping, Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    SciTech Connect

    Cunningham, K.I.; LaRock, E.J. )

    1991-10-01

    Radon concentrations range from less than 185 to 3,515 Bq m-3 throughout Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico. Concentrations in the entrance passages and areas immediately adjacent to these passages are controlled by outside air temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.

  20. Phylogenetic diversity of fungal communities in areas accessible and not accessible to tourists in Naracoorte Caves.

    PubMed

    Adetutu, Eric M; Thorpe, Krystal; Bourne, Steven; Cao, Xiangsheng; Shahsavari, Esmaeil; Kirby, Greg; Ball, Andrew S

    2011-01-01

    The fungal diversity in areas accessible and not accessible to tourists at UNESCO World Heritage-listed Naracoorte Caves was investigated with culture-dependent and culture-independent techniques for assistance in cave management protocol development. The caves were selected based on tourist numbers and configurations: Stick Tomato (open, high numbers), Alexandra (lockable openings, high numbers) and Strawhaven (control; no access). Culture-based survey revealed Ascomycota dominance irrespective of sampling area with Microascales (Trichurus sp.) being most frequently isolated. Some Hypocreales-like sequences belonging to Fusarium sp., Trichoderma sp. and Neonectria sp. (Stick Tomato) were cultured only from areas not accessible to tourists. These orders also were detected by DGGE assay irrespective of sampling area. The predominance of Ascomycota (especially Microascales) suggested their important ecological roles in these caves. Culture-independent analysis showed higher Shannon fungal diversity values (from ITS-based DGGE profiles) in tourist-accessible areas of these caves than in inaccessible areas with the fungal community banding patterns being substantially different in Stick Tomato Cave. Further investigations are needed to determine the cause of the differences in the fungal communities of Stick Tomato Cave, although cave-related factors such as use, configuration and sediment heterogeneity might have contributed to these differences.

  1. The Allegory of the Cave. Philosophy, Education, Experience: Coming into the Light.

    ERIC Educational Resources Information Center

    Blenkinsop, Sean

    2001-01-01

    A teacher describes a class activity for teaching and illuminating the allegory of the cave in Plato's Republic, a parable that illustrates Plato's thoughts on enlightenment and the educative process. Students create the cave in the classroom, recreate the experience of its inhabitants, and discuss their own reactions to the experience. (SV)

  2. Can 5-6 Year Old Children Orientate Themselves in a Cave?

    ERIC Educational Resources Information Center

    Jovignot, Francois

    1995-01-01

    Spatial capacities of 36 children ages 5-6 were tested in 3 experiments involving an electronic maze, map training and testing, and finding the way out of a cave using a map. All subjects could use simple maps; this ability improved with age. However, no subject navigated the cave without help, perhaps because of stress or task complexity. (SV)

  3. Quantitative food web analysis supports the energy-limitation hypothesis in cave stream ecosystems.

    PubMed

    Venarsky, Michael P; Huntsman, Brock M; Huryn, Alexander D; Benstead, Jonathan P; Kuhajda, Bernard R

    2014-11-01

    Energy limitation has long been the primary assumption underlying conceptual models of evolutionary and ecological processes in cave ecosystems. However, the prediction that cave communities are actually energy-limited in the sense that constituent populations are consuming all or most of their resource supply is untested. We assessed the energy-limitation hypothesis in three cave streams in northeastern Alabama (USA) by combining measurements of animal production, demand, and resource supplies (detritus, primarily decomposing wood particles). Comparisons of animal consumption and detritus supply rates in each cave showed that all, or nearly all, available detritus was required to support macroinvertebrate production. Furthermore, only a small amount of macroinvertebrate prey production remained to support other predatory taxa (i.e., cave fish and salamanders) after accounting for crayfish consumption. Placing the energy demands of a cave community within the context of resource supply rates provided quantitative support for the energy-limitation hypothesis, confirming the mechanism (limited energy surpluses) that likely influences the evolutionary processes and population dynamics that shape cave communities. Detritus-based surface ecosystems often have large detrital surpluses. Thus, cave ecosystems, which show minimal surpluses, occupy the extreme oligotrophic end of the spectrum of detritus-based food webs.

  4. Metagenomic Analysis from the Interior of a Speleothem in Tjuv-Ante's Cave, Northern Sweden

    PubMed Central

    Zepeda Mendoza, Marie Lisandra; Lundberg, Johannes; Ivarsson, Magnus; Campos, Paula; Nylander, Johan A. A.; Sallstedt, Therese; Dalen, Love

    2016-01-01

    Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante’s cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante’s cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i) an evaluation of the use of these speleothems as past biodiversity archives, ii) functional and taxonomic profiling of the speleothem’s different formation periods, and iii) taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching. PMID:26985997

  5. The small but clear gravity signal above the natural cave 'Grotta Gigante' (Trieste, Italy)

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Sampietro, Daniele; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Fabbri, Julius; Rossi, Lorenzo; Handi Mansi, Ahmed

    2014-05-01

    Gravity observations are a powerful means for detecting underground mass changes. The Italian and Slovenian Karst has a number of explored caves, several are also touristic due to their size (e.g. Grotta Gigante in Italy; Skocjianske Jame and Postojnska Jama in Slovenia). Just a few years ago another big cave was discovered by chance close to Trieste when drilling a tunnel for a motor-highway, which shows that more caves are expected to be discovered in coming years. We have acquired the gravity field above the Grotta Gigante cave, a cave roughly 100 m high and 200 m long with a traditional spring-gravity meter (Lacoste&Romberg) and height measurements made with GPS and total station. The GPS was made with two different teams and processing algorithms, to cross-check accuracy and error estimate. Some stations had to be surveyed with a classical instrument due to the vegetation which concealed the satellite positioning signal. Here we present the results of the positioning acquisitions and the gravity field. The cave produces a signal of 1.5 mGal, with a clear elongated concentric symmetry. The survey shows that a systematic coverage of the Karst would have the benefit to recover the position of all of the greater existing caves. This will have a large impact on civil and environmental purposes, since it will for example allow to plan the urban development at a safety distance from subsurface caves.

  6. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... endangered species lists. (2) Cultural. The cave contains historic properties or archaeological resources (as... habitat for organisms or animals, or contains species or subspecies of flora or fauna that are native to...) Hydrologic. The cave is a part of a hydrologic system or contains water that is important to humans,...

  7. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... endangered species lists. (2) Cultural. The cave contains historic properties or archaeological resources (as... habitat for organisms or animals, or contains species or subspecies of flora or fauna that are native to...) Hydrologic. The cave is a part of a hydrologic system or contains water that is important to humans,...

  8. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... endangered species lists. (2) Cultural. The cave contains historic properties or archaeological resources (as... habitat for organisms or animals, or contains species or subspecies of flora or fauna that are native to...) Hydrologic. The cave is a part of a hydrologic system or contains water that is important to humans,...

  9. Response of ice caves to weather extremes in the southeastern Alps, Europe

    NASA Astrophysics Data System (ADS)

    Colucci, R. R.; Fontana, D.; Forte, E.; Potleca, M.; Guglielmin, M.

    2016-05-01

    High altitude karstic environments often preserve permanent ice deposits within caves, representing the lesser-known portion of the cryosphere. Despite being not so widespread and easily reachable as mountain glaciers and ice caps, ice caves preserve much information about past environmental changes and climatic evolution. We selected 1111 ice caves from the existing cave inventory, predominantly but not exclusively located in the periglacial domain where permafrost is not dominant (i.e., with mean annual air temperature < 3 °C but not in a permafrost environment). The influence of climate and topography on ice cave distribution is also investigated. In order to assess the thickness and the inner structure of the deposits, we selected two exemplary ice caves in the Canin massif (Julian Alps) performing several multifrequency GPR surveys. A strong influence of global and local climate change in the evolution of the ice deposits has been particularly highlighted in the dynamic ice cave type, especially in regard to the role of weather extremes. The natural response of ice caves to a warming climate could lead to a fast reduction of such ice masses. The increased occurrence of weather extremes, especially warmer and more intense precipitation caused by higher mean 0 °C-isotherms, could in fact be crucial in the future mass balance evolution of such permanent ice deposits.

  10. Identification of Martian Cave Skylights Using the Temperature Change During Day and Night

    NASA Astrophysics Data System (ADS)

    Jung, Jongil; Yi, Yu; Kim, Eojin

    2014-06-01

    Recently, cave candidates have been discovered on other planets besides the Earth, such as the Moon and Mars. When we go to other planets, caves could be possible human habitats providing natural protection from cosmic threats. In this study, seven cave candidates have been found on Pavonis Mons and Ascraeus Mons in Tharsis Montes on Mars. The cave candidates were selected using the images of the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO). The Context Camera could provide images with the high resolution of 6 meter per pixel. The diameter of the candidates ranges from 50 to 100m. Cushing et al. (2007) have analyzed the temperature change at daytime and nighttime using the Thermal Emission Imaging System (THEMIS) for the sites of potential cave candidates. Similarly, we have examined the temperature change at daytime and at nighttime for seven cave candidates using the method of Cushing et al. (2007). Among those, only one candidate showed a distinct temperature change. However, we cannot verify a cave based on the temperature change only and further study is required for the improvement of this method to identify caves more clearly.

  11. Impact of a harbour construction on the benthic community of two shallow marine caves.

    PubMed

    Nepote, Ettore; Bianchi, Carlo Nike; Morri, Carla; Ferrari, Marco; Montefalcone, Monica

    2017-01-15

    Marine caves are unique and vulnerable habitats, threatened by multiple global and local disturbances. Whilst the effects of climate change on marine caves have already been investigated, no information exists about the effects of local human impacts, such as coastal development, on these habitats. This study investigated the impact of the construction of a touristic harbour on two shallow underwater marine caves in the Ligurian Sea (NW Mediterranean). As a standard methodology for monitoring marine caves does not exist yet, changes over time on the benthic community were assessed adopting two different non-taxonomic descriptors: trophic guilds and growth forms. Harbour construction caused an increase of sediment load within the caves, with a consequent decline of filter feeder organisms. Abundance of small organisms, such as encrusting and flattened sponges, was greatly reduced in comparison to organisms with larger and erect growth forms, such as domed mounds and pedunculated sponges. Our study indicated that growth forms and trophic guilds are effective descriptors for evaluating changes over time in marine caves, and could be easily standardised and applied in monitoring plans. In addition, as the harbour construction impacted differently according to the cave topography, the use of a systematic sampling in different zones of an underwater cave is recommended.

  12. Resource Documentation and Recharge Area Delineation of a Large Fluvial Karst System: Carroll Cave, Missouri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Located along Wet Glaize Creek in the central Missouri Ozarks, Toronto Spring is a distributary spring system where surface stream flow mixes with flow from the Carroll Cave system. Following recharge area delineations for Thunder River and Confusion Creek in Carroll Cave, flow from these rivers wa...

  13. DNA analysis of fecal bacteria to augment an epikarst dye trace study at Crump's Cave, Kentucky

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rainfall simulation experiment was performed to investigate the transport behavior of fecal-derived bacteria through shallow karst soils and through the epikarst. The experiment was conducted at Cave Springs Cavern located just south of Mammoth Cave National Park on the Sinkhole Plain of South Cen...

  14. All in the Training: Techniques for Enhancing Karst Landscape Education through Show Cave Interpretation

    ERIC Educational Resources Information Center

    North, Leslie; van Beynen, Philip

    2016-01-01

    Despite the abundance of karst terrains and a universal lack of knowledge about the role they play in supplying freshwater resources, informal environmental education through guided show cave tours is poorly understood. This study evaluated techniques for educating cave guides on how to disseminate information about human-karst interactions to…

  15. Paleontology. A Curriculum and Activity Guide to Mammoth Cave National Park. [Grades] 1-12.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC.

    Mammoth Cave (Kentucky) was designated as a national park in 1941 because of its beautiful hills and valleys, scenic rivers, and the vast cave system located within its boundaries. Outstanding physiographic features include karst terrains, sandstone capped plateaus, and bluffs overlooking rivers and streams, which provide an unusually wide variety…

  16. Mammoth Cave: It's Explorers, Miners, Archeologists, and Visitors. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Ward, Robert H.

    The mysterious darkness of Mammoth Cave in southwestern Kentucky, about 90 miles south of Louisville and 90 miles north of Nashville, has lured travelers to enter and warned them to stay away. From the dawn of time visitors have been awestruck by the cave's size and rugged beauty. This lesson is based on the National Register of Historic Places…

  17. Tuberculoma of the Cavernous Sinus and Meckel's Cave in a Child.

    PubMed

    Kumar, V R Roopesh; Madhugiri, Venkatesh S; Verma, Surendra Kumar; Barathi, S Deepak; Yadav, Awdhesh Kumar; Bidkar, Prasanna

    2013-01-01

    Tuberculous infection of the cavernous sinus and Meckel's cave is extremely rare. In this report, we describe a patient with tuberculoma of the cavernous sinus and Meckel's cave, extending to the petrous apex. The patient underwent microsurgical excision of the lesion and antitubercular chemotherapy resulting in a good outcome. We describe the diagnostic difficulties and review the relevant literature.

  18. Extra-axial ependymoma of posterior fossa extending to the Meckel's cave.

    PubMed

    Torun, Fuat; Tuna, Hakan; Bozkurt, Melih; Deda, Haluk

    2005-06-01

    An extra-axial ependymoma extending from the left cerebellopontine corner to the Meckel's cave is reported. This lesion's clinical, radiological, and histological characteristics are presented. This tumor's infrequent extra-axial location, extension to the Meckel's cave and possible origin are discussed.

  19. 78 FR 59923 - Cave Run Energy, LLC; Notice of Intent To File License Application, Filing of Pre-Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... Energy Regulatory Commission Cave Run Energy, LLC; Notice of Intent To File License Application, Filing.... Project No.: 14376-001. c. Date Filed: July 21, 2013. d. Submitted By: Cave Run Energy, LLC. e. Name of Project: Cave Run Hydroelectric Project. f. Location: On the Licking River, in Rowan and Bath...

  20. Occurrence and Absence of Lava Tube Caves with Some Other Volcanic Cavities; a Consideration of Human Habitation Sites on Mars

    NASA Astrophysics Data System (ADS)

    Halliday, W. R.; Favre, G.; Stefansson, A.; Whitfield, P.; Banks, N.

    2012-03-01

    Field investigation of Hawaii's Kau Desert pit craters shows that they are not connected to lave tube caves. The Seven Sisters of Arsia Mons are unlikely to contain lave tube caves. Other types of caves on Mars may provide human habitation sites.

  1. Fluid lubricated bearing assembly

    DOEpatents

    Boorse, Henry A.; Boeker, Gilbert F.; Menke, John R.

    1976-01-01

    1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on said shaft, said thrust plate having a central opening the peripheral portion of which is hermetically sealed to said housing at the open end of said cavity, and means for supplying a fluid lubricant to said thrust bearing, said thrust bearing having a lubricant-conducting path connecting said lubricant supplying means with the space between said thrust plate and collar intermediate the peripheries thereof, the surfaces of said plate and collar being constructed and arranged to inhibit radial flow of lubricant and, on rotation of said thrust collar, to draw lubricant through said path between the bearing surfaces and to increase the pressure therebetween and in said cavity and thereby exert a supporting force on said end portion of said shaft.

  2. Fault tolerant magnetic bearings

    SciTech Connect

    Maslen, E.H.; Sortore, C.K.; Gillies, G.T.; Williams, R.D.; Fedigan, S.J.; Aimone, R.J.

    1999-07-01

    A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

  3. Tribology of alternative bearings.

    PubMed

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  4. The Astrobiology of the Subsurface: Exploring Cave Habitats on Earth, Mars and Beyond

    NASA Technical Reports Server (NTRS)

    Boston, Penelope Jane

    2016-01-01

    We are using the spectacular underground landscapes of Earth caves as models for the subsurfaces of other planets. Caves have been detected on the Moon and Mars and are strongly suspected for other bodies in the Solar System including some of the ice covered Ocean Worlds that orbit gas giant planets. The caves we explore and study include many extreme conditions of relevance to planetary astrobiology exploration including high and low temperatures, gas atmospheres poisonous to humans but where exotic microbes can flourish, highly acidic or salty fluids, heavy metals, and high background radiation levels. Some cave microorganisms eat their way through bedrock, some live in battery acid conditions, some produce unusual biominerals and rare cave formations, and many produce compounds of potential pharmaceutical and industrial significance. We study these unique lifeforms and the physical and chemical biosignatures that they leave behind. Such traces can be used to provide a "Field Guide to Unknown Organisms" for developing life detection space missions.

  5. Age and origin of carlsbad cavern and related caves from 40Ar/39Ar of alunite

    PubMed

    Polyak; McIntosh; Guven; Provencio

    1998-03-20

    40Ar/39Ar dating of fine-grained alunite that formed during cave genesis provides ages of formation for the Big Room level of Carlsbad Cavern [4.0 to 3.9 million years ago (Ma)], the upper level of Lechuguilla Cave (6.0 to 5.7 Ma), and three other hypogene caves (11.3 to 6.0 Ma) in the Guadalupe Mountains of New Mexico. Alunite ages increase and are strongly correlative with cave elevations, which indicates an 1100-meter decline in the water table, apparently related to tectonic uplift and tilting, from 11.3 Ma to the present. 40Ar/39Ar dating studies of the hypogene caves have the potential to help resolve late Cenozoic climatic, speleologic, and tectonic questions.

  6. U-series dating of Paleolithic art in 11 caves in Spain.

    PubMed

    Pike, A W G; Hoffmann, D L; García-Diez, M; Pettitt, P B; Alcolea, J; De Balbín, R; González-Sainz, C; de las Heras, C; Lasheras, J A; Montes, R; Zilhão, J

    2012-06-15

    Paleolithic cave art is an exceptional archive of early human symbolic behavior, but because obtaining reliable dates has been difficult, its chronology is still poorly understood after more than a century of study. We present uranium-series disequilibrium dates of calcite deposits overlying or underlying art found in 11 caves, including the United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage sites of Altamira, El Castillo, and Tito Bustillo, Spain. The results demonstrate that the tradition of decorating caves extends back at least to the Early Aurignacian period, with minimum ages of 40.8 thousand years for a red disk, 37.3 thousand years for a hand stencil, and 35.6 thousand years for a claviform-like symbol. These minimum ages reveal either that cave art was a part of the cultural repertoire of the first anatomically modern humans in Europe or that perhaps Neandertals also engaged in painting caves.

  7. Meckel cave: computed tomographic study. Part I. Normal anatomy. Part II. Pathology

    SciTech Connect

    Kapila, A.; Chakeres, D.W.; Blanco, E.

    1984-08-01

    A formalin-fixed cadaver head with air filling the cisternal and ventricular spaces was scanned by high-resolution computed tomography (CT) in multiple planes (axial, coronal, and sagittal) through the Meckel cave. Correlation of the CT appearance of the Meckel cave was made with an anatomic dissection and whole-head band saw cross-sections. CT techniques allowed consistent and accurate definition of the Meckel cave, the fifth cranial nerve, and adjacent anatomic structures. CT findings of 13 patients with lesions of the Meckel cave are also reviewed, including six trigeminal schwannomas, three meningiomas, two secondary tumors, one glioma, and one congenital fatty tumor. Surgical confirmation was present in 11 cases. Diagnosis and determination of the extent of Meckel cave lesions is possible with the use of high-resolution CT.

  8. 9 CFR 201.49 - Requirements regarding scale tickets evidencing weighing of livestock, live poultry, and feed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... evidencing weighing of livestock, live poultry, and feed. 201.49 Section 201.49 Animals and Animal Products... regarding scale tickets evidencing weighing of livestock, live poultry, and feed. (a) When livestock, poultry or feed is weighed for the purpose of purchase, sale, acquisition, or settlement, a scale...

  9. 9 CFR 201.49 - Requirements regarding scale tickets evidencing weighing of livestock, live poultry, and feed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... evidencing weighing of livestock, live poultry, and feed. 201.49 Section 201.49 Animals and Animal Products... regarding scale tickets evidencing weighing of livestock, live poultry, and feed. (a) Livestock. When... the weigher. (b) Poultry. When live poultry is weighed for the purpose of purchase, sale,...

  10. 9 CFR 201.49 - Requirements regarding scale tickets evidencing weighing of livestock, live poultry, and feed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... evidencing weighing of livestock, live poultry, and feed. 201.49 Section 201.49 Animals and Animal Products... regarding scale tickets evidencing weighing of livestock, live poultry, and feed. (a) Livestock. When... the weigher. (b) Poultry. When live poultry is weighed for the purpose of purchase, sale,...

  11. 9 CFR 201.49 - Requirements regarding scale tickets evidencing weighing of livestock, live poultry, and feed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... evidencing weighing of livestock, live poultry, and feed. 201.49 Section 201.49 Animals and Animal Products... regarding scale tickets evidencing weighing of livestock, live poultry, and feed. (a) Livestock. When... the weigher. (b) Poultry. When live poultry is weighed for the purpose of purchase, sale,...

  12. 9 CFR 201.49 - Requirements regarding scale tickets evidencing weighing of livestock, live poultry, and feed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... evidencing weighing of livestock, live poultry, and feed. 201.49 Section 201.49 Animals and Animal Products... regarding scale tickets evidencing weighing of livestock, live poultry, and feed. (a) Livestock. When... the weigher. (b) Poultry. When live poultry is weighed for the purpose of purchase, sale,...

  13. Evidence of NAO control on subsurface ice accumulation in a 1200 yr old cave-ice sequence, St. Livres ice cave, Switzerland

    NASA Astrophysics Data System (ADS)

    Stoffel, Markus; Luetscher, Marc; Bollschweiler, Michelle; Schlatter, Frédéric

    2009-07-01

    Mid-latitude ice caves are assumed to be highly sensitive to climatic changes and thus represent a potentially interesting environmental archive. Establishing a precise chronology is, however, a prerequisite for the understanding of processes driving the cave-ice mass balance and thus allows a paleoenvironmental interpretation. At St. Livres ice cave (Jura Mountains, Switzerland), subfossil trees and organic material are abundant in the cave-ice deposit, therefore allowing the dating of individual ice layers. The dendrochronological analysis of 45 subfossil samples of Norway spruce ( Picea abies (L.) Karst.) from the overhanging front of the ice outcrop as well as the dating of seven wood samples with 14C dating allowed for a reconstruction of the St. Livres cave-ice sequence and for the determination of periods of ice accumulation and ablation. Results suggest a maximal age of 1200 ± 50 14C yr BP for the observed ice sequence and indicate the presence of four major deposition gaps dated to the 14th, 15th, mid-19th and late 19th century, which can be related with periods of positive North Atlantic Oscillation anomalies (NAO+) over the winter half-year and/or anthropogenic cave-ice abstraction. Similarly, there is evidence that periods of cave-ice accumulation as observed between AD 1877-1900 and AD 1393-1415 would correspond with phases of negative NAO indices. Cave ice represents therefore an original climate archive for the winter half-year and is complementary to other continental proxies recording preferentially summer conditions (e.g., tree rings, varves).

  14. Designing user models in a virtual cave environment

    SciTech Connect

    Brown-VanHoozer, S.; Hudson, R.; Gokhale, N.

    1995-12-31

    In this paper, the results of a first study into the use of virtual reality for human factor studies and design of simple and complex models of control systems, components, and processes are described. The objective was to design a model in a virtual environment that would reflect more characteristics of the user`s mental model of a system and fewer of the designer`s. The technology of a CAVE{trademark} virtual environment and the methodology of Neuro Linguistic Programming were employed in this study.

  15. Stalagmites from Spannagel cave (Austria) and holocene climate

    NASA Astrophysics Data System (ADS)

    Vollweiler, N.; Mangini, A.; Spötl, C.; Scholz, D.; Mühlinghaus, C.

    2009-04-01

    The Spannagel cave is located around 2,500 m asl at the end of the Tux Valley in Tyrol (Austria) close to the Hintertux glacier. While the area above the cave is ice free at present, it was covered by ice during past glacials as well as during colder periods of Interglacials. Presently, the temperature inside the cave is between 1.8° and 2.0° C. We used the d18O time-series of three stalagmites which grew in small distance from each other. This speleothem record is not influenced by effects of kinetic isotope fractionation due to the low temperatures in the cave. The stalagmites were precisely dated with the U/Th-method. The combined record (COMNISPA, Vollweiler et al. 2006) shows substantial variability within the last 9 kyr with features like the Holocene Climatic Optimum between 7.5 and 6.5 kyr, the Mediaeval Warm Period between 1.2 and 0.7 kyr and the Roman Warm Period between 2.25 and 1.7 kyr. In contrast, periods of lower temperatures are visible between 7.9 and 7.5, 5.9 and 5.1, 3.5 and 3 kyr, and during the LIA between 600 and 150 yr. The period between 5.9 and 5.1 kyr has equivalence in many records from various regions in both hemispheres corresponding to global cooling. It also includes the time of the Alpine Iceman at 5.3 kyr. The timing of the climatic variations revealed by COMNISPA agrees approximately with that shown by other Alpine archives. Joerin et al. (2006) dated wood and peat samples which were released by melting Swiss Alpine glaciers located between Engadin and Valais. Both the d18O maxima and minima recorded in COMNISPA clearly have counterparts in the glacier recession record. Comparisons of COMNISPA with other archives have shown that our stalagmite curve does not only record local climate but also the history of European climate. The extremely high correlation to the Hematite Stained Grain record of Bond et al. (2001) suggests that COMNISPA is a good archive for climate in the North Atlantic region (Mangini et al. 2007). In addition

  16. Spontaneous Meckel's cave hematoma: A rare cause of trigeminal neuralgia

    PubMed Central

    Alafaci, Concetta; Grasso, Giovanni; Granata, Francesca; Marino, Daniele; Salpietro, Francesco M.; Tomasello, Francesco

    2015-01-01

    Background: The most common etiology of classic trigeminal neuralgia (TN) is vascular compression. However, other causes must be considered. Among these, spontaneous hematoma of the Meckel's cave (MC) causing symptomatic TN is very rare. Case Description: We present the case of a 60-year-old woman with a 2-month history of left TN and diplopia. Neuroradiological examinations revealed a well-defined hematoma in the left MC. The patient underwent surgical decompression with a progressive neurological improvement. Conclusion: Despite the number of lesions potentially affecting the MC, spontaneous hemorrhage is rare but should be taken into account in the differential diagnosis. PMID:26539319

  17. Meter-long microbial ropes from euxinic cave lakes

    NASA Astrophysics Data System (ADS)

    Macalady, J. L.; Jones, D. S.; Schaperdoth, I.; Bloom, D.; McCauley, R.

    2008-12-01

    Cave divers exploring a remote conduit in the Frasassi cave system (Italy) discovered unusual 1 to 2 meter- long, rope-like microbial biofilms in the anoxic layer of a permanently stratified cave lake. Organic carbon in the rope-like biofilm has a delta 13C value of -33 per mil, indicating in situ lithautotrophic primary production and little or no input from surface-derived plant carbon. SEM/EDS of critical point dried samples showed interlocking strands of microbial-sized filaments with trapped mineral particles including S, CaCO3, silicate clays, and sulfate and phosphate minerals. Staining with the nucleic acid dye DAPI further showed that the ropes are composed of closely packed, intact microbial cells. Geochemical profiles of the stratified lake (conductivity, pH, ORP, T, oxygen, sulfide, sulfate, ammonium) delineate a sharp chemocline at ~2.3 m water depth, several meters above the ropes. Geochemical data for the water surrounding the microbial ropes suggest that little redox energy is available, and that sulfate reduction and methanogenesis should be the most favorable reactions. Radiocarbon ages for the ropes are associated with a large uncertainty due to potentially changing contributions of radiocarbon-dead limestone carbonate over time. However, the data suggest that the ropes are thousands of years older than animals in the cave system, consistent with extreme energy limitation and slow growth. Based on phylogenetic analyses of archaeal, bacterial and universal 16S rDNA clone libraries from the microbial ropes, approximately 50 percent of bacterial clones affiliate with sulfur-reducing deltaproteobacteria. Approximately 61 percent of archaeal clones (20 percent of all clones) are associated with an environmental clade of euryarchaeota commonly retrieved from deep sea sediments (MBG-D). Most other clones in the libraries grouped in clades without cultivated representatives. No clones associated with known methanogens or anaerobic methane oxidizers were

  18. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  19. Magnetic bearings for spacecraft

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1972-01-01

    Magnetic bearings have been successfully applied to motorized rotor systems in the multi-kilogram range, at speeds up to 1200 radians per second. These engineering models also indicated the need for continued development in specific areas to make them feasible for spacecraft applications. Significant power reductions have recently been attained. A unique magnetic circuit, combining permanent magnets with electromagnetic control, has a bidirectional forcing capability with improved current sensitivity. The multi-dimensional nature of contact-free rotor support is discussed. Stable continuous radial suspension is provided by a rotationally symmetric permanent magnet circuit. Two bearings, on a common shaft, counteract the normal instability perpendicular to the rotational axis. The axial direction is servoed to prevent contact. A new bearing technology and a new field of application for magnetics is foreseen.

  20. Solving bearing overheating problems

    SciTech Connect

    Jendzurski, T.

    1995-05-08

    Overheating is a major indicator, along with vibration and noise, of an underlying problem affecting a bearing or related components. Because normal operating temperatures vary widely from one application to another, no single temperature is a reliable sign of overheating in every situation. By observing an application when it is running smoothly, a technician can establish a benchmark temperature for a particular bearing arrangement. Wide deviations from this accepted norm generally indicate troublesome overheating. The list of possible causes of over-heating ranges from out-of-round housings and oversize shaft diameters to excessive lubrication and bearing preloading. These causes fall into two major categories: improper or faulty lubrication and mechanical problems, such as incorrect fits and tolerances. These are discussed along with solutions.

  1. Radial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  2. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  3. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  4. Measurements of aerosol particles in the Škocjan Caves, Slovenia.

    PubMed

    Grgić, Irena; Iskra, Ivan; Podkrajšek, Boštjan; Gerjevič, Vanja Debevec

    2014-02-01

    For the first time, continuous aerosol measurements were performed in the Škocjan Caves, one of the most important cave systems in the world, and listed by UNESCO as a natural and cultural world heritage site since 1986. Measurements of PM10 were performed during three different periods: (1) in December 2011, the average background concentration was found to be about 4 μg m(-3); (2) in June 2012, a higher concentration was measured (8 μg m(-3)); and (3) from 8 to 20 August 2012, the highest concentration of 15.3 μg m(-3) was measured. Based on the PM10 measurement results, and as compared to similar measurements outside the cave, it can be hypothesized that the increase in the cave's aerosol concentration during the summer was connected to both the higher number of visitors and the polluted atmospheric air entering the cave upon entering of the cave system. Additional measurement of nanoparticles with scanning mobility particle sizer spectrometer (size between 14.1 and 710.5 nm) confirmed these findings; during the summer period, a severe raise in the total aerosol concentration of 30-50 times was found when groups of visitors entered the cave. Our results on nanoparticles demonstrated that we were able to detect very small changes and variations in aerosol concentration inside the cave. To our knowledge, these are the first results on nanoaerosol measurements in a cave, and we believe that such measurements may lead to the implementation of better protection of delicate cave systems.

  5. Microbial communities in dark oligotrophic volcanic ice cave ecosystems of Mt. Erebus, Antarctica

    PubMed Central

    Tebo, Bradley M.; Davis, Richard E.; Anitori, Roberto P.; Connell, Laurie B.; Schiffman, Peter; Staudigel, Hubert

    2015-01-01

    The Earth's crust hosts a subsurface, dark, and oligotrophic biosphere that is poorly understood in terms of the energy supporting its biomass production and impact on food webs at the Earth's surface. Dark oligotrophic volcanic ecosystems (DOVEs) are good environments for investigations of life in the absence of sunlight as they are poor in organics, rich in chemical reactants and well known for chemical exchange with Earth's surface systems. Ice caves near the summit of Mt. Erebus (Antarctica) offer DOVEs in a polar alpine environment that is starved in organics and with oxygenated hydrothermal circulation in highly reducing host rock. We surveyed the microbial communities using PCR, cloning, sequencing and analysis of the small subunit (16S) ribosomal and Ribulose-1,5-bisphosphate Carboxylase/Oxygenase (RubisCO) genes in sediment samples from three different caves, two that are completely dark and one that receives snow-filtered sunlight seasonally. The microbial communities in all three caves are composed primarily of Bacteria and fungi; Archaea were not detected. The bacterial communities from these ice caves display low phylogenetic diversity, but with a remarkable diversity of RubisCO genes including new deeply branching Form I clades, implicating the Calvin-Benson-Bassham (CBB) cycle as a pathway of CO2 fixation. The microbial communities in one of the dark caves, Warren Cave, which has a remarkably low phylogenetic diversity, were analyzed in more detail to gain a possible perspective on the energetic basis of the microbial ecosystem in the cave. Atmospheric carbon (CO2 and CO), including from volcanic emissions, likely supplies carbon and/or some of the energy requirements of chemoautotrophic microbial communities in Warren Cave and probably other Mt. Erebus ice caves. Our work casts a first glimpse at Mt. Erebus ice caves as natural laboratories for exploring carbon, energy and nutrient sources in the subsurface biosphere and the nutritional limits on

  6. Envitonmental monitoring and radiation protection in Škocjan Caves, Slovenia

    NASA Astrophysics Data System (ADS)

    Debevec Gerjeviè, V.; Jovanovič, P.

    2012-04-01

    Škocjan Caves were listed as UNESCO World Heritage Sites in 1986, due to their exceptional significance for cultural and natural heritage. Park Škocjan Caves is located in South Eastern part of Slovenia. It was established with aim of conserving and protecting exceptional geomorphological, geological and hydrological outstanding features, rare and endangered plant and animal species, paleontological and archaeological sites, ethnological and architectural characteristics and cultural landscape and for the purpose of ensuring opportunities for suitable development, by the National Assembly of the Republic of Slovenia in 1996. Park Škocjan Caves established monitoring that includes caves microclimate parameters: humidity, CO2, wind flow and radon concentration and daughter products. The approach in managing the working place with natural background radiation is complex. Monitoring of Radon has been functioning for more than ten years now. Presentation will show the dynamic observed in the different parts of the caves, related to radon daughter products and other microclimatic data. Relation of background radiation to carrying capacity will be explained. Implementing the Slovene legislation in the field of radiation protection, we are obligated to perform special measurements in the caves and also having our guides and workers in the caves regularly examined according to established procedure. The medical exams are performed at Institution of Occupational Safety, Ljubljana in order to monitor the influence of Radon to the workers in the cave. The equivalent dose for each employed person is also established on regular basis and it is part of medical survey of workers in the caves. A system of education of the staff working in the caves in the field of radiation protection will be presented as well.

  7. Karst show caves - how DTN technology as used in space assists automatic environmental monitoring and tourist protection - experiment in Postojna Cave

    NASA Astrophysics Data System (ADS)

    Gabrovšek, F.; Grašič, B.; Božnar, M. Z.; Mlakar, P.; Udén, M.; Davies, E.

    2014-02-01

    The paper presents an experiment demonstrating a novel and successful application of delay- and disruption-tolerant networking (DTN) technology for automatic data transfer in a karst cave early warning and measuring system. The experiment took place inside the Postojna Cave in Slovenia, which is open to tourists. Several automatic meteorological measuring stations are set up inside the cave, as an adjunct to the surveillance infrastructure; the regular data transfer provided by the DTN technology allows the surveillance system to take on the role of an early warning system (EWS). One of the stations is set up alongside the railway tracks, which allows the tourist to travel inside the cave by train. The experiment was carried out by placing a DTN "data mule" (a DTN-enabled computer with WiFi connection) on the train and by upgrading the meteorological station with a DTN-enabled WiFi transmission system. When the data mule is in the wireless drive-by mode, it collects measurement data from the station over a period of several seconds as the train without stopping passes the stationary equipment, and delivers data at the final train station by the cave entrance. This paper describes an overview of the experimental equipment and organization allowing the use of a DTN system for data collection and an EWS inside karst caves where there is regular traffic of tourists and researchers.

  8. Karst show caves - how DTN technology as used in space assists automatic environmental monitoring and tourist protection - experiment in Postojna cave

    NASA Astrophysics Data System (ADS)

    Gabrovšek, F.; Grašič, B.; Božnar, M. Z.; Mlakar, P.; Udén, M.; Davies, E.

    2013-10-01

    The paper presents an experiment demonstrating a novel and successful application of Delay- and Disruption-Tolerant Networking (DTN) technology for automatic data transfer in a karst cave Early Warning and Measuring System. The experiment took place inside the Postojna Cave in Slovenia, which is open to tourists. Several automatic meteorological measuring stations are set up inside the cave, as an adjunct to the surveillance infrastructure; the regular data transfer provided by the DTN technology allows the surveillance system to take on the role of an Early Warning System (EWS). One of the stations is set up alongside the railway tracks, which allows the tourist to travel inside the cave by train. The experiment was carried out by placing a DTN "data mule" (a DTN-enabled computer with WiFi connection) on the train and by upgrading the meteorological station with a DTN-enabled WiFi transmission system. When the data mule is in the wireless drive-by mode, it collects measurement data from the station over a period of several seconds as the train passes the stationary equipment, and delivers data at the final train station by the cave entrance. This paper describes an overview of the experimental equipment and organisation allowing the use of a DTN system for data collection and an EWS inside karst caves where there is a regular traffic of tourists and researchers.

  9. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  10. Comparison of bacterial communities from lava cave microbial mats to overlying surface soils from Lava Beds National Monument, USA

    PubMed Central

    Read, Kaitlyn J. H.; Hughes, Evan M.; Spilde, Michael N.

    2017-01-01

    Subsurface habitats harbor novel diversity that has received little attention until recently. Accessible subsurface habitats include lava caves around the world that often support extensive microbial mats on ceilings and walls in a range of colors. Little is known about lava cave microbial diversity and how these subsurface mats differ from microbial communities in overlying surface soils. To investigate these differences, we analyzed bacterial 16S rDNA from 454 pyrosequencing from three colors of microbial mats (tan, white, and yellow) from seven lava caves in Lava Beds National Monument, CA, USA, and compared them with surface soil overlying each cave. The same phyla were represented in both surface soils and cave microbial mats, but the overlap in shared OTUs (operational taxonomic unit) was only 11.2%. Number of entrances per cave and temperature contributed to observed differences in diversity. In terms of species richness, diversity by mat color differed, but not significantly. Actinobacteria dominated in all cave samples, with 39% from caves and 21% from surface soils. Proteobacteria made up 30% of phyla from caves and 36% from surface soil. Other major phyla in caves were Nitrospirae (7%) followed by minor phyla (7%), compared to surface soils with Bacteroidetes (8%) and minor phyla (8%). Many of the most abundant sequences could not be identified to genus, indicating a high degree of novelty. Surface soil samples had more OTUs and greater diversity indices than cave samples. Although surface soil microbes immigrate into underlying caves, the environment selects for microbes able to live in the cave habitats, resulting in very different cave microbial communities. This study is the first comprehensive comparison of bacterial communities in lava caves with the overlying soil community. PMID:28199330

  11. Comparison of bacterial communities from lava cave microbial mats to overlying surface soils from Lava Beds National Monument, USA.

    PubMed

    Lavoie, Kathleen H; Winter, Ara S; Read, Kaitlyn J H; Hughes, Evan M; Spilde, Michael N; Northup, Diana E

    2017-01-01

    Subsurface habitats harbor novel diversity that has received little attention until recently. Accessible subsurface habitats include lava caves around the world that often support extensive microbial mats on ceilings and walls in a range of colors. Little is known about lava cave microbial diversity and how these subsurface mats differ from microbial communities in overlying surface soils. To investigate these differences, we analyzed bacterial 16S rDNA from 454 pyrosequencing from three colors of microbial mats (tan, white, and yellow) from seven lava caves in Lava Beds National Monument, CA, USA, and compared them with surface soil overlying each cave. The same phyla were represented in both surface soils and cave microbial mats, but the overlap in shared OTUs (operational taxonomic unit) was only 11.2%. Number of entrances per cave and temperature contributed to observed differences in diversity. In terms of species richness, diversity by mat color differed, but not significantly. Actinobacteria dominated in all cave samples, with 39% from caves and 21% from surface soils. Proteobacteria made up 30% of phyla from caves and 36% from surface soil. Other major phyla in caves were Nitrospirae (7%) followed by minor phyla (7%), compared to surface soils with Bacteroidetes (8%) and minor phyla (8%). Many of the most abundant sequences could not be identified to genus, indicating a high degree of novelty. Surface soil samples had more OTUs and greater diversity indices than cave samples. Although surface soil microbes immigrate into underlying caves, the environment selects for microbes able to live in the cave habitats, resulting in very different cave microbial communities. This study is the first comprehensive comparison of bacterial communities in lava caves with the overlying soil community.

  12. Bacterial Activity and Geochemical Reactions in Submerged Cave Development -- Impact on Karst Aquifers in Florida

    NASA Astrophysics Data System (ADS)

    Herman, J. S.; Franklin, R. B.; Mills, A. L.; Giannotti, A. L.; Tysall, T. N.

    2008-05-01

    Elucidation of coupled mechanisms of sulfide oxidation and biomass generation supports an improved understanding the driving forces behind acid production, calcite dissolution, cave development, and karst aquifers characterization. Wekiwa Springs Cave and DeLeon Springs Cave, located in central Florida, both contain prolific bacterial mats from which sulfur-oxidizing bacteria have been identified. Wekiwa Springs Cave, a submerged cave developed in the Hawthorne Formation and located near Orlando, Florida, has groundwater discharge from the Floridian aquifer system, with some contribution from surficial and intermediate aquifers. The spring is the headwater of the Wekiwa River and releases a total of 170,000 m3 of water per day. The ceiling and walls are heavily covered (10 cm thick) with three morphologically distinct types of microbial mats largely comprising sulfur-oxidizing bacteria. Analysis of nearby groundwater collected from wells confirms sulfide concentrations in the regional groundwater of ~ 1.5 mg/L, though sulfide concentrations for water collected in the cave are below detection. Dissolved oxygen concentration in the water is low (<0.5 mg/L). DeLeon Springs Cave, a submerged cave located in Volusia County, Florida, is a single conduit with an average discharge of ~ 70,000 m3 of water per day, and water chemistry data suggest the presence of a saline seep in the system. Dense microbial mats cover the rock surfaces of the cave; the mats are highly filamentous, with long white streamers that often extend 1-2 feet from the cave wall. Microscopic analysis has confirmed the presence of sulfur granules within these bacterial cells, similar to those observed in the Wekiwa cave organisms. The water chemistry in DeLeon Springs Cave, however, is distinct from that of Wekiwa Springs Cave. Though DO, Fetotal, and HS- values are similar for the two sites, the concentration of ions such as Cl-, Na+, and SO42- are considerably higher at DeLeon. A similar contrast

  13. Palliative Care Issues in Amyotrophic Lateral Sclerosis: An Evidenced-Based Review.

    PubMed

    Karam, Chafic Y; Paganoni, Sabrina; Joyce, Nanette; Carter, Gregory T; Bedlack, Richard

    2016-02-01

    As palliative care physicians become increasingly involved in the care of patients with amyotrophic lateral sclerosis (ALS), they will be asked to provide guidance regarding the use of supplements, diet, exercise, and other common preventive medicine interventions. Moreover, palliative care physicians have a crucial role assisting patients with ALS in addressing health care decisions to maximize quality of life and cope with a rapidly disabling disease. It is therefore important for palliative care physicians to be familiar with commonly encountered palliative care issues in ALS. This article provides an evidenced-based review of palliative care options not usually addressed in national and international ALS guidelines.

  14. Palliative Care Issues in Amyotrophic Lateral Sclerosis: An Evidenced-Based Review

    PubMed Central

    Karam, Chafic Y.; Paganoni, Sabrina; Joyce, Nanette; Carter, Gregory T.; Bedlack, Richard

    2015-01-01

    As palliative care physicians become increasingly involved in the care of patients with amyotrophic lateral sclerosis (ALS), they will be asked to provide guidance regarding the use of supplements, diet, exercise, and other common preventive medicine interventions. Moreover, palliative care physicians have a crucial role assisting patients with ALS in addressing health care decisions to maximize quality of life and cope with a rapidly disabling disease. It is therefore important for palliative care physicians to be familiar with commonly encountered palliative care issues in ALS. This article provides an evidenced-based review of palliative care options not usually addressed in national and international ALS guidelines. PMID:25202033

  15. Behavior Therapy for Tic Disorders: An Evidenced-based Review and New Directions for Treatment Research

    PubMed Central

    McGuire, Joseph F.; Ricketts, Emily J.; Piacentini, John; Murphy, Tanya K.; Storch, Eric A.; Lewin, Adam B.

    2015-01-01

    Behavior therapy is an evidenced-based intervention with moderate-to-large treatment effects in reducing tic symptom severity among individuals with Persistent Tic Disorders (PTDs) and Tourette’s Disorder (TD). This review describes the behavioral treatment model for tics, delineates components of evidence-based behavior therapy for tics, and reviews the empirical support among randomized controlled trials for individuals with PTDs or TD. Additionally, this review discusses several challenges confronting the behavioral management of tics, highlights emerging solutions for these challenges, and outlines new directions for treatment research. PMID:26543797

  16. Forensic Fluid Dynamics and the Indian Spring (1991) cave collapse problem

    NASA Astrophysics Data System (ADS)

    Nof, D.

    2013-05-01

    The collapse of the Indian spring cave (Florida) in 1991 was unique because it occurred while cave divers were in the cave. For the most part, the submerged cave is large enough to accommodate a passing truck so the cave divers were not in touch with its walls and it is hard to imagine why would it naturally collapse just when the divers were in it. Recently, Nof and Paldor (2010) resolved this apparent paradox by suggesting that resonance in the air pockets in the cavern, created by breathing (open circuit) divers, may have contributed to the collapse. In this scenario, divers present in the cavern during the dive may have (unknowingly) caused the collapse through the pressurized air/gas that they release with each breath. When the breathing period of the diver(s) matches the natural oscillations period of the "cave oscillator", the ensuing resonance causes the air pressure in the pockets to increase uncontrollably. Here, we place the above theory on a more solid ground. To do so, we first extended the resonance theory from our original two-pockets, symmetrical U-tube model (with two identical branches that were not specifically identified within the cave system) to a one (identified) pocket in the cavern and a very broad basin (identified, of course) that serves as the other branch of the U-tube. Our methodology is to apply familiar fluid dynamics principles to the situation that occurred in the cave. We did so, step-by-step, on the basis of our interviews with four out of the five surviving cave-divers. Namely, we dissected their testimonies to arrive at a physically plausible scenario determined on basis of a fluid dynamics application to the natural flow in the cave and the flow induced by the compressed air released by the divers as well as the collapsed mud. We found that the oscillation period was larger than what we earlier calculated (still relevant to the case, nevertheless), and that, in contrast to what most cave divers believe, there was a temporary

  17. Carbon Cycling in the Karst of Northwestern Arkansas: Linking the Soil and Cave Environments

    NASA Astrophysics Data System (ADS)

    Knierim, K.; Pollock, E. D.; Hays, P. D.; Covington, M. D.

    2014-12-01

    Carbon is a ubiquitous element in karst systems. Stable isotope analysis of carbon reservoirs provides information about carbon cycling, allowing carbon to be tracked along groundwater flow paths from the surface atmosphere, through the soil and epikarst, and into caves and karst aquifers. In the Ozarks of northwestern Arkansas, karstified carbonates are covered with a mantle of cherty regolith, which can serve as either a sink or source of carbon. Samples for δ13C analysis of gaseous CO2 and aqueous DIC were collected from two soil lysimeters installed in the soil zone above a cave, a drip-water pool in a side-passage of the cave, and three locations along the cave stream and spring outlet. A two-component, concentration-dependent mixing model of δ13C-CO2 was used to calculate the proportions of cave-air CO2 sourced from the surface atmosphere versus the soil zone. Median CO2 concentrations were 2,578 ±1,504 ppm in the soil and 1,026 ±939 ppm in the cave, and CO2 concentration increased with outside surface temperature. Median δ13C-CO2 was -21.5 ±2.1 ‰ in the soil and -17.5 ±4.3 ‰ in the cave. Median DIC concentrations were 1.7 ±1.0 mg/L in the soil and 23.3 ±6.6 mg/L in the cave, and as discharge increased, DIC concentration decreased in the cave. Median δ13C-DIC was -19.5 ±2.5 ‰ in the soil and -14.3 ±1.6 ‰ in the cave. The concentration and isotopic composition of carbon species varied seasonally; for example, in the soil and cave, CO2 was greatest in the summer and lowest in the winter. Additionally, the proportion of soil CO2 contributing to the cave air was lowest during fall (8 %) and greatest during summer (71 %). At the spring outlet during storm events, DIC and calcite saturation decreased and δ13C-DIC became lighter, likely as pre-event water stored in the soil zone was displaced by storm-event water. Data indicate that, depending on the time of year, cave carbon species were sourced from the surface atmosphere, soil, and deeper

  18. Detrital cave sediments record Late Quaternary hydrologic and climatic variability in northwestern Florida, USA

    NASA Astrophysics Data System (ADS)

    Winkler, Tyler S.; van Hengstum, Peter J.; Horgan, Meghan C.; Donnelly, Jeffrey P.; Reibenspies, Joseph H.

    2016-04-01

    Detrital sediment in Florida's (USA) submerged cave systems may preserve records of regional climate and hydrologic variability. However, the basic sedimentology, mineralogy, stratigraphic variability, and emplacement history of the successions in Florida's submerged caves remains poorly understood. Here we present stratigraphic, mineralogical, and elemental data on sediment cores from two phreatic cave systems in northwestern Florida (USA), on the Dougherty Karst Plain: Hole in the Wall Cave (HITW) and Twin Cave. Water flowing through these caves is subsurface flow in the Apalachicola River drainage basin, and the caves are located just downstream from Jackson Blue (1st magnitude spring, > 2.8 m3 s- 1 discharge). Sedimentation in these caves is dominated by three primary sedimentary styles: (i) ferromanganese deposits dominate the basal recovered stratigraphy, which pass upsection into (ii) poorly sorted carbonate sediment, and finally into (iii) fine-grained organic matter (gyttja) deposits. Resolving the emplacement history of the lower stratigraphic units was hampered by a lack of suitable material for radiocarbon dating, but the upper organic-rich deposits have a punctuated depositional history beginning in the earliest Holocene. For example, gyttja primarily accumulated in HITW and Twin Caves from ~ 5500 to 3500 cal yr. BP, which coincides with regional evidence for water-table rise of the Upper Floridian Aquifer associated with relative sea-level rise in the Gulf of Mexico, and evidence for invigorated drainage through the Apalachicola River drainage basin. Gyttja sediments were also deposited in one of the caves during the Bølling/Allerød climate oscillation. Biologically, these results indicate that some Floridian aquatic cave (stygobitic) ecosystems presently receive minimal organic matter supply in comparison to prehistoric intervals. The pre-Holocene poorly sorted carbonate sediment contains abundant invertebrate fossils, and likely documents a period

  19. Composite Bear Canister

    NASA Technical Reports Server (NTRS)

    Chung, W. Richard; Jara, Steve; Suffel, Susan

    2003-01-01

    To many national park campers and mountain climbers saving their foods in a safe and unbreakable storage container without worrying being attacked by a bear is a challenging task. In some parks, the park rangers have mandated that park visitors rent a bear canister for their food storage. Commercially available bear canisters are made of ABS plastic, weigh 2.8 pounds, and have a 180 cubic inch capacity for food storage. A new design with similar capacity was conducted in this study to reduce its weight and make it a stiffer and stronger canister. Two prototypes incorporating carbon prepreg with and without honeycomb constructions were manufactured using hand lay-up and vacuum bag forming techniques. A 6061-T6-aluminum ring was machined to dimensions in order to reinforce the opening area of the canister. Physical properties (weight and volume) along with mechanical properties (flexural strength and specific allowable moment) of the newly fabricated canisters are compared against the commercial ones. The composite canister weighs only 56% of the ABS one can withstand 9 times of the force greater. The advantages and limitations of using composite bear canisters will be discussed in the presentation.

  20. Hybrid superconductor magnet bearings

    NASA Astrophysics Data System (ADS)

    Chu, Wei-Kan

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  1. The Teddy Bears' Disc.

    ERIC Educational Resources Information Center

    Laurillard, Diana

    1985-01-01

    Reports an evaluation of the Teddy Bear disc, an interactive videodisc developed at the Open University for a second-level course in metallurgy and materials technology. Findings from observation of students utilizing the videodisc are reviewed; successful design features and design problems are considered; and development costs are outlined. (MBR)

  2. Hybrid superconductor magnet bearings

    NASA Technical Reports Server (NTRS)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  3. History of ball bearings

    NASA Technical Reports Server (NTRS)

    Dowson, D.; Hamrock, B. J.

    1981-01-01

    The familiar precision rolling-element bearings of the twentieth century are products of exacting technology and sophisticated science. Their very effectiveness and basic simplicity of form may discourage further interest in their history and development. Yet the full story covers a large portion of recorded history and surprising evidence of an early recognition of the advantages of rolling motion over sliding action and progress toward the development of rolling-element bearings. The development of rolling-element bearings is followed from the earliest civilizations to the end of the eighteenth century. The influence of general technological developments, particularly those concerned with the movement of large building blocks, road transportation, instruments, water-raising equipment, and windmills are discussed, together with the emergence of studies of the nature of rolling friction and the impact of economic factors. By 1800 the essential features of ball and rolling-element bearings had emerged and it only remained for precision manufacture and mass production to confirm the value of these fascinating machine elements.

  4. Magnetically leviated superconducting bearing

    DOEpatents

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  5. Optimal Synchronizability of Bearings

    NASA Astrophysics Data System (ADS)

    Araújo, N. A. M.; Seybold, H.; Baram, R. M.; Herrmann, H. J.; Andrade, J. S., Jr.

    2013-02-01

    Bearings are mechanical dissipative systems that, when perturbed, relax toward a synchronized (bearing) state. Here we find that bearings can be perceived as physical realizations of complex networks of oscillators with asymmetrically weighted couplings. Accordingly, these networks can exhibit optimal synchronization properties through fine-tuning of the local interaction strength as a function of node degree [Motter, Zhou, and Kurths, Phys. Rev. E 71, 016116 (2005)PLEEE81539-3755]. We show that, in analogy, the synchronizability of bearings can be maximized by counterbalancing the number of contacts and the inertia of their constituting rotor disks through the mass-radius relation, m˜rα, with an optimal exponent α=α× which converges to unity for a large number of rotors. Under this condition, and regardless of the presence of a long-tailed distribution of disk radii composing the mechanical system, the average participation per disk is maximized and the energy dissipation rate is homogeneously distributed among elementary rotors.

  6. Hybrid superconductor magnet bearings

    SciTech Connect

    Chu, W.

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB`s) utilize high temperature superconductors (HTS`s) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS`s, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, the authors present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  7. Bearings Incorporating Deadband Rollers

    NASA Technical Reports Server (NTRS)

    Gualtieri, Guy V.

    1996-01-01

    Bearings in high-pressure turbopump redesigned to incorporate rollers allowing limited axial motion within small deadband. Does not permit radial deadband motion. Axial deadband motion used for rotor-thrust-balance control. Design eliminates some nonlinearities in dynamics of pump rotor and assists in suppressing vibrations at harmonics of frequency of rotation.

  8. Classification of Thermal Patterns at Karst Springs and Cave Streams

    USGS Publications Warehouse

    Luhmann, A.J.; Covington, M.D.; Peters, Albert J.; Alexander, S.C.; Anger, C.T.; Green, J.A.; Runkel, Anthony C.; Alexander, E.C.

    2011-01-01

    Thermal patterns of karst springs and cave streams provide potentially useful information concerning aquifer geometry and recharge. Temperature monitoring at 25 springs and cave streams in southeastern Minnesota has shown four distinct thermal patterns. These patterns can be divided into two types: those produced by flow paths with ineffective heat exchange, such as conduits, and those produced by flow paths with effective heat exchange, such as small fractures and pore space. Thermally ineffective patterns result when water flows through the aquifer before it can equilibrate to the rock temperature. Thermally ineffective patterns can be either event-scale, as produced by rainfall or snowmelt events, or seasonal scale, as produced by input from a perennial surface stream. Thermally effective patterns result when water equilibrates to rock temperature, and the patterns displayed depend on whether the aquifer temperature is changing over time. Shallow aquifers with seasonally varying temperatures display a phase-shifted seasonal signal, whereas deeper aquifers with constant temperatures display a stable temperature pattern. An individual aquifer may display more than one of these patterns. Since karst aquifers typically contain both thermally effective and ineffective routes, we argue that the thermal response is strongly influenced by recharge mode. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  9. Early Neanderthal constructions deep in Bruniquel Cave in southwestern France.

    PubMed

    Jaubert, Jacques; Verheyden, Sophie; Genty, Dominique; Soulier, Michel; Cheng, Hai; Blamart, Dominique; Burlet, Christian; Camus, Hubert; Delaby, Serge; Deldicque, Damien; Edwards, R Lawrence; Ferrier, Catherine; Lacrampe-Cuyaubère, François; Lévêque, François; Maksud, Frédéric; Mora, Pascal; Muth, Xavier; Régnier, Édouard; Rouzaud, Jean-Noël; Santos, Frédéric

    2016-06-02

    Very little is known about Neanderthal cultures, particularly early ones. Other than lithic implements and exceptional bone tools, very few artefacts have been preserved. While those that do remain include red and black pigments and burial sites, these indications of modernity are extremely sparse and few have been precisely dated, thus greatly limiting our knowledge of these predecessors of modern humans. Here we report the dating of annular constructions made of broken stalagmites found deep in Bruniquel Cave in southwest France. The regular geometry of the stalagmite circles, the arrangement of broken stalagmites and several traces of fire demonstrate the anthropogenic origin of these constructions. Uranium-series dating of stalagmite regrowths on the structures and on burnt bone, combined with the dating of stalagmite tips in the structures, give a reliable and replicated age of 176.5 thousand years (±2.1 thousand years), making these edifices among the oldest known well-dated constructions made by humans. Their presence at 336 metres from the entrance of the cave indicates that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity.

  10. A Neanderthal lower molar from Stajnia Cave, Poland.

    PubMed

    Dąbrowski, P; Nowaczewska, W; Stringer, C B; Compton, T; Kruszyński, R; Nadachowski, A; Stefaniak, K; Urbanowski, M

    2013-04-01

    The primary aim of this study was to conduct a taxonomic assessment of the second of three isolated human teeth found in the Stajnia Cave (north of the Carpathians, Poland) in 2008. The specimen was located near a human tooth (S5000), which was identified by Urbanowski et al. (2010) as a Neanderthal permanent upper molar. Both of these teeth were excavated from the D2 layer, which belongs to the D stratigraphic complex comprising the archaeological assemblage associated with the Micoquian tradition. An Ursus spelaeus bone and Mammuthus primigenius tooth that were also excavated from the D2 layer were dated to >49,000 years BP (by AMS (14)C) and 52.9 ka BP (by U-Th), respectively. The sediment overlying stratigraphic complex D was dated to 45.9 ka BP by the OSL method. The S4300 tooth is a lower first or second permanent molar belonging to an individual other than that who once possessed the S5000 tooth. The S4300 tooth exhibits a combination of traits typical of Neanderthal lower molars, including a mid-trigonid crest, large anterior fovea, taurodontism and subvertical grooves on the interproximal face, indicating that this tooth belonged to a Neanderthal individual. The S4300 tooth from Stajnia Cave is one of the oldest human remains found in Poland.

  11. Step back! Niche dynamics in cave-dwelling predators

    NASA Astrophysics Data System (ADS)

    Mammola, Stefano; Piano, Elena; Isaia, Marco

    2016-08-01

    The geometry of the Hutchinson's hypervolume derives from multiple selective pressures defined, on one hand, by the physiological tolerance of the species, and on the other, by intra- and interspecific competition. The quantification of these evolutionary forces is essential for the understanding of the coexistence of predators in light of competitive exclusion dynamics. We address this topic by investigating the ecological niche of two medium-sized troglophile spiders (Meta menardi and Pimoa graphitica). Over one year, we surveyed several populations in four subterranean sites in the Western Italian Alps, monitoring monthly their spatial and temporal dynamics and the associated physical and ecological variables. We assessed competition between the two species by means of multi regression techniques and by evaluating the intersection between their multidimensional hypervolumes. We detected a remarkable overlap between the microclimatic and trophic niche of M. menardi and P. graphitica, however, the former -being larger in size- resulted the best competitor in proximity of the cave entrance, causing the latter to readjust its spatial niche towards the inner part, where prey availability is scarcer ("step back effect"). In parallel to the slight variations in the subterranean microclimatic condition, the niche of the two species was also found to be seasonal dependent, varying over the year. With this work, we aim at providing new insights about the relationships among predators, demonstrating that energy-poor environments such as caves maintain the potential for diversification of predators via niche differentiation and serve as useful models for theoretical ecological studies.

  12. Magnetic-Bearing Test Fixture

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.; Poole, William L.

    1991-01-01

    Microcomputer-controlled magnetic-bearing test fixture used to develop approaches to design of controls for magnetic bearing actuators designed and constructed. Includes load cells connected to bar, in turn, connected through screw positioners to geared drive motors. Position of equivalent suspended element sensed by position sensors and controlled by drive motors. Provides control of gap in magnetic bearing and of current in electromagnet coil. Measurements made include magnetic-bearing gaps, magnetic flux in bearing gaps, and bearing forces. Approaches to linearization and control developed by use of fixture applicable to wide range of small-gap suspension systems.

  13. Bearing-Cartridge Damping Seal

    NASA Technical Reports Server (NTRS)

    Goggins, David G.; Scharrer, Joseph K.; Chen, Wei C.

    1991-01-01

    In proposed design for improved ball-bearing cartridge, damping seal in form of thin-layer fluid journal bearing incorporated into cartridge. Damping seal acts as auxiliary bearing, relieving bearing balls of significant portions of both static and dynamic bearing loads. Damping from seal reduces dynamic loads even further by reducing amplitude of vibrations in second vibrational mode of rotor, which mode occurs when rotor turning at nearly full operating speed. Intended for use in high-pressure-oxygen turbopump of Space Shuttle main engine, also applicable to other turbomachinery bearings.

  14. Flexure Bearing Reduces Startup Friction

    NASA Technical Reports Server (NTRS)

    Clingman, W. Dean

    1991-01-01

    Design concept for ball bearing incorporates small pieces of shim stock, wire spokes like those in bicycle wheels, or other flexing elements to reduce both stiction and friction slope. In flexure bearing, flexing elements placed between outer race of ball bearing and outer ring. Elements flex when ball bearings encounter small frictional-torque "bumps" or even larger ones when bearing balls encounter buildups of grease on inner or outer race. Flexure of elements reduce high friction slopes of "bumps", helping to keep torque between outer ring and inner race low and more nearly constant. Concept intended for bearings in gimbals on laser and/or antenna mirrors.

  15. Lubricant effects on bearing life

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1986-01-01

    Lubricant considerations for rolling-element bearings have within the last two decades taken on added importance in the design and operation of mechanical systems. The phenomenon which limits the useful life of bearings is rolling-element or surface pitting fatigue. The elastohydrodynamic (EHD) film thickness which separates the ball or roller surface from those of the raceways of the bearing directly affects bearing life. Chemical additives added to the lubricant can also significantly affect bearings life and reliability. The interaction of these physical and chemical effects is important to the design engineer and user of these systems. Design methods and lubricant selection for rolling-element bearings are presented and discussed.

  16. Cultural ecology of prehistoric parasitism on the Colorado Plateau as evidenced by coprology.

    PubMed

    Reinhard, K J

    1988-11-01

    The study of coprolites (desiccated feces) is recognized as a viable method for analyzing parasitism of prehistoric peoples. Eight species of helminth parasites, including nematodes, cestodes, and acanthcephalans, have been recovered from archaeological sites on the Colorado Plateau. The comparative analysis of parasitological findings illustrates the effects of changing subsistence strategies and varying life-style on prehistoric human parasitism. This comparative study is based on the analysis of coprolites recovered from one Archaic hunter-gatherer site and two Anasazi agricultural villages. Hunter-gatherers are represented by coprolites from Dust Devil Cave in south-eastern Utah. Coprolites of prehistoric agriculturalists from Antelope House in Canyon de Chelly, Arizona, and from Salmon Ruin in northwestern New Mexico were studied. The results demonstrate that helminth parasitism increased with the advent of agriculture. Between the agricultural sites, differences in patterns of excreta disposal, foraging behavior, and local ecology resulted in pronounced variations in both percentage of coprolites containing parasite remains and the number of parasite species represented.

  17. Exploring the diversity of blood-sucking Diptera in caves of Central Africa.

    PubMed

    Obame-Nkoghe, Judicaël; Rahola, Nil; Ayala, Diego; Yangari, Patrick; Jiolle, Davy; Allene, Xavier; Bourgarel, Mathieu; Maganga, Gael Darren; Berthet, Nicolas; Leroy, Eric-Maurice; Paupy, Christophe

    2017-03-21

    Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods. In Africa, previous studies identified mosquitoes, sand flies and biting midges as the main potential vectors of cave-dwelling pathogens. However, to understand their involvement in pathogen spillover, it is crucial to characterize their diversity, community composition and dynamics. Using CDC light traps, we collected hematophagous Diptera in six caves of Gabon during one-shot or longitudinal sampling, and investigated their species diversity and dynamics in relation with external rainfall. Overall, we identified 68 species of mosquitoes, sand flies and biting midges, including 45 new records for Gabon. The dominant species were: Uranotaenia nigromaculata, Anopheles smithii s.l., Culex. rima group and Culex quasiguiarti for mosquitoes, Spelaeophlebotomus gigas and Spelaeomyia emilii for sand flies and the Culicoides trifasciellus group and Culicoides fulvithorax for biting midges. The survey revealed that species assemblages were cave-specific and included mainly troglophilous and trogloxenous species. Both diversity and abundance varied according to the cave and sampling time, and were significantly associated with rainfall. These associations were modulated by the cave specific environmental conditions. Moreover, the presence of trogloxenous and troglophilous species could be of high significance for pathogen transfers between cave and epigeous hosts, including humans.

  18. Rock fall simulation at Timpanogos Cave National Monument, American Fork Canyon, Utah, USA

    USGS Publications Warehouse

    Harp, E.L.; Dart, R.L.; Reichenbach, P.

    2011-01-01

    Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at the cave entrance and exit in 1976. Numerous rock fall incidents, including a near miss in 2000 in the vicinity of the trail below the cave exit, have led to a decision to extend the shelter at the cave exit to protect visitors from these ongoing rock fall events initiating from cliffs immediately above the cave exit. Three-dimensional rock fall simulations from sources at the top of these cliffs have provided data from which to assess the spatial frequencies and velocities of rock falls from the cliffs and to constrain the design of protective measures to reduce the rock fall hazard. Results from the rock fall simulations are consistent with the spatial patterns of rock fall impacts that have been observed at the cave exit site. ?? 2011 Springer-Verlag.

  19. Rock fall simulation at Timpanogos Cave National Monument, American Fork Canyon, Utah, USA

    USGS Publications Warehouse

    Harp, Edwin L.; Dart, Richard L.; Reichenbach, Paola

    2011-01-01

    Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at the cave entrance and exit in 1976. Numerous rock fall incidents, including a near miss in 2000 in the vicinity of the trail below the cave exit, have led to a decision to extend the shelter at the cave exit to protect visitors from these ongoing rock fall events initiating from cliffs immediately above the cave exit. Three-dimensional rock fall simulations from sources at the top of these cliffs have provided data from which to assess the spatial frequencies and velocities of rock falls from the cliffs and to constrain the design of protective measures to reduce the rock fall hazard. Results from the rock fall simulations are consistent with the spatial patterns of rock fall impacts that have been observed at the cave exit site.

  20. Unexpected diversity of sandflies (Diptera: Psychodidae) in tourist caves in Northern Thailand.

    PubMed

    Sukantamala, Jedsada; Sing, Kong-Wah; Jaturas, Narong; Polseela, Raxsina; Wilson, John-James

    2016-10-19

    Certain species of Phlebotomine sandflies (Diptera: Psychodidae) are vectors of the protozoa which causes leishmaniasis. Sandflies are found breeding in enclosed places like caves. Thailand is a popular tourist destination, including for ecotourism activities like caving, which increases the risk of contact between tourists and sandflies. Surveillance of sandflies is important for monitoring this risk but identification of species based on morphology is challenged by phenotypic plasticity and cryptic diversity. DNA barcodes have been used for the identification of sandflies in Thailand. We collected sandflies using CDC light trap from four tourist caves in Northern Thailand. Female sandflies were provisionally sorted into 13 morphospecies and 19 unidentified specimens. DNA was extracted from the thorax and legs of sandflies and the DNA barcode region of cytochrome c oxidase I mtDNA amplified and sequenced. The specimens were sorted into 22 molecular operational taxonomic units (MOTU) based on the 145 DNA barcodes, which is significantly more than the morphospecies. Several of the taxa thought to be present in multiple caves, based on morphospecies sorting, split into cave-specific MOTU which likely represent cryptic species. Several MOTU reported in an earlier study from Wihan Cave, Thailand, were also found in these caves. This supports the use of DNA barcodes to investigate species diversity of sandflies and their useful role in surveillance of sandflies in Thailand.