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Effect of soil-rock system on speleothems weathering in Bailong Cave, Yunnan Province, China.

Bailong Cave with its well-developed Middle Triassic calcareous dolomite's system was opened as a show cave for visitors in 1988. The speleothem scenery has been strongly weathered as white powder on the outer layers. Study of the cave winds, permeability of soil-rock system and the chemical compositions of the dripping water indicated: (1) The cave dimension structure distinctively affects the cave winds, which were stronger at narrow places. (2) Based on the different soil grain size distribution, clay was the highest in composition in the soil. The response sense of dripping water to the rainwater percolation was slow. The density of joints and other openings in dolomite make the dolomite as mesh seepage body forming piles of thin and high columns and stalactites. (3) Study of 9 dripping water samples by HYDROWIN computer program showed that the major mineral in the water was dolomite.

Biodegradation, Environmental↗

Contribution of bats to the maintenance of Histoplasma capsulatum in a cave microfocus.

Bracken Cave, a large natural cavern located 25 miles northeast of San Antonio, Texas, serves as nursery roost for millions of Mexican free-tailed bats (Tadarida brasiliensis). Ten days after spending several hours in the cave in early May 1979, three graduate students presented with signs and symptoms compatible with acute pulmonary histoplasmosis. A study was initiated to determine the presence and location of Histoplasma capsulatum in the cave and its inhabitants. The fungus was cultured directly from guano at five of nine sites sampled. Sentinel mice left for several hours at one of three positive sites developed histoplasmosis within 30 days after exposure. Autopsy was done on a total of 28 bats and their lungs, liver and spleen were cultured for viable H. capsulatum. In addition, sera from 58 bats were tested for antibodies to H. capsulatum, using a double diffusion test employing commercial reagents. All bat cultures and sera were negative. We conclude that the students were infected by massive exposure to viable H. capsulatum in aerosols created by disturbing guano deposits near the mouth of the cave. Tadarida brasiliensis contributes to a suitable environment for fungal proliferation, but does not appear to play an active role in the maintenance or dissemination of the fungus in Bracken Cave.

Animals↗

Atmospheric 222Rn in tourist caves of Slovenia, Yugoslavia.

Radon-222 concentrations in the air of 12 tourist caves in Slovenia, Yugoslavia were measured. In almost all the caves concentrations are higher than in the outdoor air, with the highest concentration in the Tabor Cave at about 6000 Bq m-3. From the 222Rn concentrations obtained, the activity of 222Rn inhaled by a visitor breathing cave air was calculated, and the bronchial dose was estimated. The inhaled activity and the bronchial dose were highest in the Tabor Cave with values of 10 kBq and 540 microSv, respectively.

Air Pollutants↗

Food and reproduction of Trichomycterus itacarambiensis, cave catfish from south-eastern Brazil

Trichomycterus itacarambiensis is a troglobitic (cave-restricted) catfish found in the Olhos d'Agua Cave, Itacarambi Co., Minas Gerais, south-eastern Brazil. The cave is subject to a pronounced seasonality, and is flooded during part of the rainy season. The pigmentation degree is variable in T. itacarambiensis, a third of the population being true albinos; the eyes vary from normal to externally invisible. As expected for a cave-dwelling fish, T. itacarambiensis is a carnivorous generalist, which preys mainly on autochthonous insects and earthworms. It is a chemically oriented predator of bottom and surface animals, using foraging tactics also used by other cave catfishes, such as the pimelodids Pimelodella kronei and Imparfinis sp. However, bottom feeding seems to be more important for T. itacarambiensis than for the latter. There is a severe feeding stress during the dry season, when few individuals are able to get food. Reproduction is seasonal, with increased reproductive activity at the end of the rainy period, as recorded for Imparfinis sp., also a species living in a semi-arid region with a well-defined dry season. It is estimated that up to 50% of the female T. itacarambiensis can reproduce every year, a high proportion for a troglobitic fish species. At least during the study period, pigmented individuals reproduced more frequently than the albinos.

Journal Article↗

One eye but no vision: cave fish with induced eyes do not respond to light.

One of the most intriguing questions in evolutionary biology is the degree to which behavior is a necessary consequence of morphology. We explore this issue by examining phototactic behavior in epigean (eyed surface-dwelling) and troglomorphic (blind cave) forms of the teleost Astyanax fasciatus whose eyes were modified during embryogenesis by removing one or both lens vesicles from the epigean form or by transplanting the lens vesicle from an epigean fish into the optic cup of a blind cave form. Lens removal results in eye degeneration and blindness in adult epigean fish, whereas lens transplantation stimulates growth of the eye, inducing the development of optic tissues in the normally eyeless adult cave fish. Photoresponsiveness was examined by placing fish in an aquarium with one half illuminated and the other half dark and scoring their presence in the illuminated or dark half. Both the eyeless epigean fish and cave fish with induced eyes are indifferent to the illumination whereas the surface forms are scotophilic, suggesting that optic development and phototactic behavior are decoupled.

Animals↗

The depositional context of the early upper paleolithic human fossils from the Koneprusy (Zlatý kůn) and Mladec caves, Czech republic.

The caves of Mladec I and II (Moravia) and Koneprusy (Bohemia) are principal hominid Early Upper Paleolithic sites in Central Europe that require a complex reconsideration from several viewpoints. The focus of this paper is on the depositional context of human fossils, which is clearer from the documentation of Koneprusy, excavated during the 1950s, than from the early reports about Mladec. Both caves are multi-floor underground karstic systems penetrated by vertical fissures and chimneys, where the fossils were found in restricted areas, related to debris cones accumulated under the chimneys. These associations are confirmed using Surfer reconstruction of the original fillings. It appears certain for Koneprusy and highly probable for Mladec that the fossils fell in through the chimneys. This does not mean that living animals and humans never entered the interior of the caves (traces of gnawing by hyenas are visible), but it makes it unlikely that the human paleontological accumulations were the result of human activity within the cave chambers.

Animals↗

Comparative ultrastructural investigations of the pineal organ of the blind cave fish, Anoptichthys jordani, and its ancestor, the eyed river fish, Astyanax mexicanus.

A comparative ultrastructural study has been made of the pineal organ in specimens of two closely related populations of the characid fish, Astyanaz mexicanus. The specimens of one population are living in the river, under natural light conditions. The specimens of the other population, originally described as Anoptichthys jordani, are living in a completely dark cave. In specimens of both populations the pineal organ consists of a spindle shaped end-vesicle, connected to the diencephalic roof by a slender stalk. The pineal tissue is compact and consists predominantly of glia-like supporting cells and sensory cells resembling the photoreceptor cells of the lateral vertebrate eye. Phagocytotic microglia-like cells can be found in close contact with the outer segments of the sensory cells. Nerve cells are located in the neighbourhood of neuropil formations, in which synaptic contacts are established between sensory cells and nerve cells. From these nerve cells fibers are emerging, forming the pineal tract that runs down the pineal stalk towards the diencephalon. On the basis of the ultrastructure described by other authors it is concluded that the pineal organ in specimens of the river population of Astyanax mexicanus resembles the pineal organ of other fish species. In specimens of the river population, reared under normal light-dark conditions for 3, 9 or 18 months, conspicuous morphological changes have not been detected in the presumably light-sensitive outer segments of the sensory cells or in other parts of the pineal tissue. In specimens of the cave populations, reared under identical conditions, an age-dependent, gradual regression of the regular outer segment organization of the pineal sensory cells takes place. In other parts of the pineal tissue, only small morphological changes can be observed. In specimens of the cave population, reared in constant darkness, the regression of the pineal outer segment organization begins earlier and is obvious. It is postulated that the gradual age-dependent regression of the regular organization of the outer segments in the pineal organ of cave specimens of Astyanax mexicanus is genetically determined and indicates a regressive evolution of the pineal light sensitivity. The expression of the regressive traits is dependent on the environmental light conditions.

Age Factors↗

High resolution CT of Meckel's cave.

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.

Adult↗

Immunocytochemical demonstration of visual pigments in the degenerate retinal and pineal photoreceptors of the blind cave salamander (Proteus anguinus).

Visual pigments in the regressed eye and pineal of the depigmented neotenic urodele, the blind cave salamander (Proteus anguinus anguinus), were studied by immunocytochemistry with anti-opsin antibodies. The study included light- and electron-microscopic investigations of both the eye and the pineal organ. A comparison was made with the black pigmented subspecies Proteus anguinus parkelj (black proteus), which has a normal eye structure. In the retina of the black proteus, we found principal rods, red-sensitive cones and a third photoreceptor type, which might represent a blue- or UV-sensitive cone. Photoreceptors in the regressed eye of the blind cave salamanders from the Planina cave contained degenerate outer segments, consisting of a few whorled discs and irregular clumps of membranes. The great majority of these outer segments showed immunolabelling for the red-sensitive cone opsin and only a few of them were found to be positive for rhodopsin. An even more pronounced degeneration was observed in the photoreceptors of the animals derived from the Otovec doline, which are completely devoid of an outer segment, most of them not even possessing an inner segment. Even in some of these highly degenerate cells, the presence of rhodopsin could be detected in the plasma membrane; however, immunoreactions with antibodies recognizing cone visual pigment were negative. In the pineals of all studied animals, the degenerate photoreceptor outer segments were recognized exclusively by the antibody against the red-sensitive cone opsin. The presence of immunopositive visual pigments indicates the possibility of a retained light sensitivity in the blind cave salamander photoreceptors.

Animals↗

Contralateral approach to carotid cave aneurysms.

BACKGROUND: To evaluate the surgical approach and clipping of aneurysms located at the carotid cave region. METHOD: Between 1980 and 1998 we have adopted the well known ipsilateral approach for exposure and securing of carotid cave aneurysms. In four patients, we had the opportunity to use a contralateral approach to carotid cave aneurysms, with easier dissection and application of a simple aneurysmal clip. The visual acuity of the patients did not deteriorate from the pre-operative level. FINDING AND INTERPRETATION: Aneurysms located at the carotid cave region may be approached easily and safely through a contralateral craniotomy with application of the aneurysm clip from an angle medial and inferior to the optic nerve.

Carotid Artery, Internal↗

Bacterial diversity and ecosystem function of filamentous microbial mats from aphotic (cave) sulfidic springs dominated by chemolithoautotrophic "Epsilonproteobacteria".

Filamentous microbial mats from three aphotic sulfidic springs in Lower Kane Cave, Wyoming, were assessed with regard to bacterial diversity, community structure, and ecosystem function using a 16S rDNA-based phylogenetic approach combined with elemental content and stable carbon isotope ratio analyses. The most prevalent mat morphotype consisted of white filament bundles, with low C:N ratios (3.5-5.4) and high sulfur content (16.1-51.2%). White filament bundles and two other mat morphotypes had organic carbon isotope values (mean delta13C=-34.7 per thousand, 1sigma=3.6) consistent with chemolithoautotrophic carbon fixation from a dissolved inorganic carbon reservoir (cave water, mean delta13C=-7.4 per thousand for two springs, n=8). Bacterial diversity was low overall in the clone libraries, and the most abundant taxonomic group was affiliated with the "Epsilonproteobacteria" (68%), with other bacterial sequences affiliated with Gammaproteobacteria (12.2%), Betaproteobacteria (11.7%), Deltaproteobacteria (0.8%), and the Acidobacterium (5.6%) and Bacteriodetes/Chlorobi (1.7%) divisions. Six distinct epsilonproteobacterial taxonomic groups were identified from the microbial mats. Epsilonproteobacterial and bacterial group abundances and community structure shifted from the spring orifices downstream, corresponding to changes in dissolved sulfide and oxygen concentrations and metabolic requirements of certain bacterial groups. Most of the clone sequences for epsilonproteobacterial groups were retrieved from areas with high sulfide and low oxygen concentrations, whereas Thiothrix spp. and Thiobacillus spp. had higher retrieved clone abundances where conditions of low sulfide and high oxygen concentrations were measured. Genetic and metabolic diversity among the "Epsilonproteobacteria" maximizes overall cave ecosystem function, and these organisms play a significant role in providing chemolithoautotrophic energy to the otherwise nutrient-poor cave habitat. Our results demonstrate that sulfur cycling supports subsurface ecosystems through chemolithoautotrophy and expand the evolutionary and ecological views of "Epsilonproteobacteria" in terrestrial habitats.

Biodiversity↗

The 'human revolution' in lowland tropical Southeast Asia: the antiquity and behavior of anatomically modern humans at Niah Cave (Sarawak, Borneo).

Recent research in Europe, Africa, and Southeast Asia suggests that we can no longer assume a direct and exclusive link between anatomically modern humans and behavioral modernity (the 'human revolution'), and assume that the presence of either one implies the presence of the other: discussions of the emergence of cultural complexity have to proceed with greater scrutiny of the evidence on a site-by-site basis to establish secure associations between the archaeology present there and the hominins who created it. This paper presents one such case study: Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 in the West Mouth of the Great Cave of a modern human skull, the 'Deep Skull,' controversially associated with radiocarbon dates of ca. 40,000 years before the present. A new chronostratigraphy has been developed through a re-investigation of the lithostratigraphy left by the earlier excavations, AMS-dating using three different comparative pre-treatments including ABOX of charcoal, and U-series using the Diffusion-Absorption model applied to fragments of bones from the Deep Skull itself. Stratigraphic reasons for earlier uncertainties about the antiquity of the skull are examined, and it is shown not to be an 'intrusive' artifact. It was probably excavated from fluvial-pond-desiccation deposits that accumulated episodically in a shallow basin immediately behind the cave entrance lip, in a climate that ranged from times of comparative aridity with complete desiccation, to episodes of greater surface wetness, changes attributed to regional climatic fluctuations. Vegetation outside the cave varied significantly over time, including wet lowland forest, montane forest, savannah, and grassland. The new dates and the lithostratigraphy relate the Deep Skull to evidence of episodes of human activity that range in date from ca. 46,000 to ca. 34,000 years ago. Initial investigations of sediment scorching, pollen, palynomorphs, phytoliths, plant macrofossils, and starch grains recovered from existing exposures, and of vertebrates from the current and the earlier excavations, suggest that human foraging during these times was marked by habitat-tailored hunting technologies, the collection and processing of toxic plants for consumption, and, perhaps, the use of fire at some forest-edges. The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest.

Animals↗

Phylogeny of the cave shrimp Troglocaris: Evidence of a young connection between Balkans and Caucasus.

The remarkably discontinuous distribution of the cave shrimp genus Troglocaris in South France, West Balkans, and West Caucasus has long been considered a biogeographic enigma. To solve it, its phylogeny was reconstructed by analyzing sequences from two mitochondrial (cytochrome oxidase I and 16S rRNA) and one nuclear gene (28S rRNA) using maximum likelihood, parsimony and Bayesian inference. The genus was found to be polyphyletic because the French taxon T. inermis had no direct common ancestry with other Troglocaris taxa but was sister to the epigean freshwater atyid Dugastella valentina. All other Troglocaris species constituted a well-supported monophylum, the second cave shrimp genus Spelaeocaris nested within. The monophylum had a well-defined structure: (1) a clade restricted to the Dinaric area of the Western Balkans containing the type species T. anophthalmus along with some unnamed species, and (2) a geographically mixed clade split between the Caucasian T. kutaissiana species complex on one, and T. hercegovinensis, S. pretneri, plus an unnamed taxon on the other side. It was surprising to find the dichotomy between the Caucasian and one of the West-Balkan lineages so low in the phylogenetic hierarchy of the genus. Taking into account molecular rates of other decapods, we tentatively dated this split at 6-11 Myr. This time is in agreement with the brackish and freshwater phase of the Paratethys thus allowing for a freshwater common ancestor of Caucasian and Dinaric cave shrimps. This would weaken the marine relicts hypothesis that has often been invoked to explain the distribution of freshwater cave species with close marine relatives.

Animals↗

Evolution in Hawaiian cave-adapted isopods (Oniscidea: Philosciidae): vicariant speciation or adaptive shifts?

We assessed evolutionary relationships among Hawaiian cave-adapted isopods using a maximum-likelihood criterion to analyze cytochrome oxidase I nucleotide sequences. Results support morphological data that two genera of philosciid isopods have invaded caves independently in the islands. In the genus Littorophiloscia, a sister relationship between a surface-dwelling species, L. hawaiiensis, and an undescribed cave species was corroborated. This evidence, along with the known parapatric distributions between species, supports a speciation event by an adaptive shift on the island of Hawaii from a marine littoral to a terrestrial subterranean habitat. The monophyletic genus Hawaiioscia contains four known obligate cave-dwelling species, each of which occurs on a separate island. However, despite present-day allopatric distributions between Hawaiioscia species, the geographic and phylogenetic patterns are not sufficient to support a vicariant mode of speciation. Instead, we believe that the known species of Hawaiioscia evolved from a widespread ancestral surface species or a group of closely related species through multiple, independent adaptive shifts on each of the islands of Kauai, Oahu, Molokai, and Maui. This is the first molecular investigation of evolutionary relationships between surface-dwelling and cavernicolous arthropods in Hawaii and it suggests that simple vicariance is insufficient to explain the evolution of troglobites in tropical zones.

Adaptation, Physiological↗

The information for catching fly balls: judging and intercepting virtual balls in a CAVE.

Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy--keeping constant the rate of change of the tangent of the elevation angle (d(tan(alpha))/dt)--leads a catcher to the right location at the right time to intercept a fly ball. Previous studies showed the ability to detect the information and the consistency of running patterns with the use of the strategy. However, only direct manipulation of information can show its use. Participants were asked to intercept virtual balls in a Cave Automated Virtual Environment (CAVE) or to judge whether balls would pass behind or in front of them. Catchers in the CAVE successfully intercepted virtual balls with their forehead. Furthermore, the timing of judgments was related to the patterns of changing d(tan(alpha))/dt. The advantages and disadvantages of a CAVE as a tool for studying interceptive action are discussed.

Adult↗

Reassessing Coxcatlan Cave and the early history of domesticated plants in Mesoamerica.

Reanalysis and direct accelerator mass spectrometry radiocarbon dating of the cucurbit assemblage from Coxcatlan Cave provide information on the timing and sequence of the initial appearance of three domesticated plants in the Tehuacán Valley (Puebla, Mexico) and allow reassessment of the overall temporal context of plant domestication in Mexico. Cucurbita pepo is the earliest documented domesticate in the cave, dating to 7,920 calibrated calendrical (cal) years B.P. The bottle gourd (Lagenaria siceraria) is dated at 7,200 cal years B.P. Cucurbita argyrosperma does not appear until 2,065 cal years B.P. The earlier identification of Cucurbita moschata specimens is not confirmed. Seventy-one radiocarbon dates, including 23 accelerator mass spectrometry dates on cucurbits, provide ample evidence of postdepositional vertical displacement of organic materials in the western half of Coxcatlan Cave, but they also indicate that the eastern half of the cave was largely undisturbed.

Archaeology↗

Methodology of radon monitoring and dose estimates in Postojna Cave, Slovenia.

Due to the specific work regime in the Postojna Cave, which depends primarily on the daily number of visitors, and on seasonal variations in air radon concentrations, an optimal methodology for radon and progeny measurement and dose calculation was sought. The program of measurement throughout the years was optimized, and now comprises 3-mo exposures of etched-track detectors, and twice a year, 8-10-d measurements using continuous monitors. Radon concentrations range from about 500 Bq m(-3) in winter to about 6,000 Bq m(-3) in summer, and equilibrium factors range from 0.42 to 0.69 in winter and from 0.33 to 0.86 in summer. Radiation doses from radon decay products for employees in the cave were calculated according to the ICRP 65 methodology. The basic input data are radon concentrations and equilibrium factors at two selected locations in the cave and the records of the time spent by a worker in the cave. Effective doses received by employees annually ranged from 0.02 to 8.4 mSv.

Environmental Exposure↗

An extensive cranial base meningioma extending bilaterally into Meckel's cave: case report.

OBJECTIVE AND IMPORTANCE: A patient with an extensive cranial base meningioma that included bilateral invasion of Meckel's cave underwent surgical resection and had an unexpected rare complication, malocclusion from bilateral trigeminal dysfunction. CLINICAL PRESENTATION: A 19-year-old male patient was admitted to our hospital with alternating painful ophthalmoplegia. He had been blind since the age of 10 years. At the time of admission, neurological findings included bilateral visual loss and optic atrophy. Magnetic resonance images showed an extensive tumor located at the planum sphenoidale, tuberculum sellae, and bilaterally at Meckel's cave and the medial tentorial incisura. INTERVENTION: The patient underwent a two-stage operation. During the first procedure, the masses in the planum sphenoidale, tuberculum sellae, and the left side of Meckel's cave were excised intradurally. At the second operation, the mass in the right side of Meckel's cave was excised extradurally and the tentorial mass was removed intradurally. The patient's postoperative course was complicated by bilateral trigeminal nerve dysfunction, which caused malocclusion. CONCLUSION: Bilateral dysfunction of the trigeminal nerve may cause a number of problems. Thus, extreme caution must be taken to preserve the function of this nerve.

Adult↗