نتایج جستجو برای: bolbol cave

تعداد نتایج: 6999  

2013
BRIAN D. COWAN MICHAEL C. OSBORNE JAY L. BANNER

The growth rate and composition of cave calcite deposits (speleothems) are often used as proxies for past environmental change. There is, however, the potential for bias in the speleothem record due to seasonal fluctuations in calcite growth and dripwater chemistry. It has been proposed that the growth rate of speleothem calcite in Texas caves varies seasonally in response to density-driven flu...

2013
Markus Friedrich

Synopsis Cave-adapted animals are characterized by extreme reduction or complete absence of eyes, reflecting their lack of exposure to daylight. Given the overall constancy of abiotic variables in the cave environment, one would also expect the relaxation and eventual loss of circadian rhythms, and with it, the regressive evolution of the underlying genetic biological clock. Remarkably, however...

2013
Masato Yoshizawa Kelly E. O’Quin William R. Jeffery

Cave-dwelling animals exhibit remarkable convergence in multiple cave-related traits, yet the genetic mechanisms responsible for the evolution and integration of many such traits remain unclear. Astyanax mexicanus is a model cave-dwelling fish with sighted surface-dwelling (surface fish) and blind cave-dwelling (cavefish) forms. Using a genetic cross between these morphs, we discovered signific...

2015
ROBERT ZLOT MICHAEL BOSSE

Existing methods of cave survey are time consuming and require significantly more time than naturally moving through the cave. The efficiency of these methods, even in the case of state-of-the-art laser-scanning technology, is fundamentally limited by the requirement that measurements be taken at static locations. We present a mobile approach to cave mapping, in which a lightweight 3D laser sca...

2017
Saber Sadeghi Meysam Dashan Mohammad Javad Malek-Hosseini

BACKGROUND The best-known dangerous spiders belong to the six genera. The genus Loxosceles or violin spiders are well known for their ability to cause skin necrosis or loxoscelism. All Loxosceles species have medical importance due to their necrotizing venom. The present article reports the occurrence of L. rufescens in Charkhab Cave, south of Iran (Larestan). METHODS The specimens were colle...

2016
Mary C. Christman Daniel H. Doctor Matthew L. Niemiller David J. Weary John A. Young Kirk S. Zigler David C. Culver

One of the most challenging fauna to study in situ is the obligate cave fauna because of the difficulty of sampling. Cave-limited species display patchy and restricted distributions, but it is often unclear whether the observed distribution is a sampling artifact or a true restriction in range. Further, the drivers of the distribution could be local environmental conditions, such as cave humidi...

2017
Kathleen H Lavoie Ara S Winter Kaitlyn J H Read Evan M Hughes Michael N Spilde Diana E Northup

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 i...

2004
BOAZ TSABAN

Gasarch, Golub, and Srinivasan studied the Robin Hood game in the case of random, memoryless strategies. In this brief note we extend their main result to the case of bounded memory, and clarify several questions raised by them. 1. The Robin Hood game The Robin Hood game RH(r, s, A) is defined for functions r, s : N → N such that 1 ≤ r(i) < s(i) for each i, and for a set A, as follows: (1) On d...

2017
Mingyi Tian

A remarkable aphaenopsian beetle, a sympatric species of Qianotrechus tenuicollis Uéno, 2000, was newly discovered in Cave Mahuang Dong of Shuanghe Dong cave system, the longest cave system of China in Suiyang County, northern Guizhou Province. To categorize this striking but still unknown species, a new genus and species are proposed: Shuangheaphaenops elegansgen. n., sp. n. Relationships of S...

2017
George M. Crothers

The prehistory of the Mammoth Cave area has been of interest to archeologists for more than a century because of the remarkable preservation in the dry cave environment. Beginning with the antiquarian search for mummified bodies in the early nineteenth century up to the most modern scientific research, Mammoth Cave has revealed important information about the Native Americans who lived near and...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید