Search results for "Cave"
showing 10 items of 606 documents
The influence of light attenuation on the biogeomorphology of a marine karst cave, the Puerto Princesa Underground River, Palawan, The Philippines
2014
Diversity, ecology, distribution and biogeography of Diplura
2021
1. Diplura is the sister group to insects and one of the three basal hexapod groups with unique entognathan mouthparts. The order is divided into 10 families, which include 1008 species in 141 genera, with a high proportion of monotypic genera. They are ubiquitous in soils and subsurface terrestrial habitats, as well as have an important role in overall biogeochemical cycles. 2. We present the first comprehensive review of the global biodiversity and ecology of Diplura. We highlight four aspects of this basal hexapod group: diversity in morpho logical body plans and sizes; ecology in terrestrial environments from soil to caves; food preference and trophic levels, and their biogeographical a…
[9] Identification of carrier systems in plasma membranes of mammalian cells involved in transport of l-arginine
1999
Publisher Summary This chapter describes the transport systems and the corresponding carrier proteins involved in the L-arginine transport that have been described till date. The chapter also discusses the methods that have been used to characterize L-arginine transport in nitric oxide (NO) producing cells or tissues. L-arginine transport is mediated by multiple carrier systems, some of which have not yet been identified at a molecular level. It is conceivable that a modification of a carrier or an associated protein could alter its transport activity, resulting in the appearance of a carrier with altered transport characteristics. Considerable progress has been made in identifying cationic…
Molecular phylogeny, biogeographic history, and evolution of cave-dwelling taxa in the European harvestman genusIschyropsalis(Opiliones: Dyspnoi)
2015
Abstract We estimated a multigenic molecular phylogeny and reconstructed biogeographic history for the European harvestman genus Ischyropsalis C.L. Koch 1839 (Dyspnoi). To reconstruct historical biogeographic patterns we conducted an algorithmic VIP analysis which revealed patterns consistent with a vicariance-dominated history. The existing morphology-based systematic framework for Ischyropsalis is mostly inconsistent with molecular phylogenetic results, and a new informal system is established that recognizes three main clades and several sub-clades. Species-level analyses revealed two non-monophyletic species (I. pyrenaea Simon 1872 and I. luteipes Simon 1872); subspecies of I. pyrenaea …
Pathogenesis of Atherosclerosis: The Alternative Hypothesis
1998
The concept that oxidation is the major single event underlying the transformation of LDL to a proinflammatory molecule dominates the world literature. An alternative hypothesis on the pathogenesis of atherosclerosis will be presented here. We have found that nonoxidative, enzymatic modification of LDL with ubiquitous enzymes also transforms the molecule to an atherogenic moiety. Enzymatically altered LDL (E-LDL) shares major properties in common with lipoproteins that have been isolated from atherosclerotic lesions. It activates complement and is recognized by a scavenger receptor on human macrophages, thus inducing foam cell formation. Uptake of E-LDL is accompanied by induction of MCP−1 …
Overland flow generation on hillslopes of complex topography: analytical Solutions
2007
The analytical solution of the overland flow equations developed by Agnese et al. (2001; Hydrological Processes15: 3225–3238) for rectangular straight hillslopes was extended to convergent and divergent surfaces and to concave and convex profiles. Towards this aim, the conical convergent and divergent surfaces are approximated by a trapezoidal shape, and the overland flow is assumed to be always one-dimensional. A simple ‘shape factor’ accounting for both planform geometry and profile shape was introduced: for each planform geometry, a brachistochrone profile was obtained by minimizing a functional containing a slope function of the profile. Minima shape factors are associated with brachist…
Nitrogen-Doped Carbon Nanodots-Ionogels: Preparation, Characterization, and Radical Scavenging Activity
2018
Hybrid diimidazolium-based ionogels were obtained by dispersing nitrogen-doped carbon nanodots (NCNDs) in ionic liquid (IL) solutions and by using dicationic organic salts as gelators. The properties of the NCND-ionogels were studied in terms of thermal stability, mechanical strength, morphology, rheological, and microscopic analyses. Insights into the formation of the hybrid soft material were attained from kinetics of sol-gel phase transition and from estimating the size of the aggregates, obtained from opacity and resonance light-scattering measurements. We demonstrate that, on one hand, NCNDs were able to favor the gel formation both in the presence of gelating and nongelating ILs. On t…
Multiple sediment proxies from Jaraguá cave, Brazil
2019
Multiple paleoclimate, paleovegetation and paleoenvironmental records from Jaraguá cave, located at center of South America. In this dataset that covers the last 28,000 year is included δ13C and δ18O values and 87Sr/86Sr ratios in stalagmites combined with XRF-derived elemental chemistry, δ13Corg, total organic carbon and total inorganic carbon (carbonate) in a sedimentary profile from the same cave.
Stability and marginal bone loss in implants placed using piezoelectric osteotomy versus conventional drilling: systematic review and meta-analysis.
2021
Background The main objective of this systematic review was to compare primary and secondary implant stability between placement with piezoelectric osteotomy and conventional drilling, comparing marginal bone losses as a secondary objective. Material and Methods An electronic search was conducted using PubMed (MEDLINE), Scopus, and Cochrane Library (Wiley) databases, besides a manual search. Results A total of 153 articles were retrieved, 39 from Pubmed, 44 from Scopus, and 70 from the Cochrane Library. After removing duplicates, 112 articles (1 from the manual search) were screened, and 9 were finally selected for qualitative and statistical analyses. Conclusions Piezoelectric surgery is a…
No room for males in caves : Female‐biased sex ratio in subterranean amphipods of the genus Niphargus
2021
Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a dataset of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing …