184,174 research outputs found
Alkaline rocks and their economic and geodynamic significance through geological time
No full textAlkaline igneous rocks have a relative excess of alkalis over silica. Most are silica undersaturated and contain normative nepheline and real feldspathoids (nepheline, leucite). Although alkaline rocks make up only about 1% of total igneous rocks by volume, their diverse mineralogy accounts for 90% of all igneous rock names proposed by the IUGS. They occur in all tectonic settings; in the ocean basins and on the continents, along mid-ocean ridges (rare), on oceanic islands, in subduction zones in the oceans and along continental margins, as well as along rift zones. Alkaline rocks commonly include alkali basalts and foidites, tephrites, phonolites, trachytes and their intrusive equivalents, including lamprophyres and carbonatites. In the literature, a plethora of local names for alkaline rocks from different localities have been created and many geoscientists still consider them as petrological curiosities. However, their study can significantly aid the interpretation of mantle evolution, ancient terranes and their geodynamic settings. Additionally, alkaline rocks may host world-class precious- and rare-metal mineralization. During recent years, the exploration interest in critical and rare metal deposits (Nb, rare earth elements (REEs) and Th) has increased dramatically as they represent vital resources for the so-called ‘green energy transition’. This Special Publication presents new comprehensive data, results and findings on alkaline rocks from different terranes worldwide and uses their mineralogy and geochemical fingerprints in order to elucidate their petrogenesis, tectonic settings and mineralization potential. This volume is not only of interest for igneous petrologists, but also for exploration geologists prospecting for precious- and rare-metal mineralization worldwide
Hydrological Changes in the Arctic, the Antarctic, and the Himalaya
No full textThe chapter enumerates the importance of glaciers on global climate, livelihood, economics, and their hydrological implications. Climate warming has raised an alarming signal on water reserves, especially on Earth's cryosphere that acts as hydrological insurance for glacier-fed rivers and a key driver for the ocean ecosystem through their freshwater supply and salinity regulation. Key issues have been discussed to understand the cryosphere system and its effect on the hydrological systems
Characterizing the Effect of Static Magnetic Fields on C. elegans Using Microfluidics
No full textIn nature, several organisms possess a magnetic compass to navigate or migrate them to desired locations. It is thought that these organisms may use biogenic magnetic matter or light-sensitive photoreceptors to sense and orient themselves in magnetic fields. To unravel the underlying principles of magnetosensitivity and magnetoreception, previous experiments have been conducted on bacteria, vertebrates, crustaceans, and insects. In this study, the model organism, C. elegans, is used to test their response and sensitivity to static magnetic fields in the range of 5 milli Tesla to 120 milli Tesla. Single wild-type C. elegans are put in microfluidic channels and exposed to permanent magnets for five cycles of thirty-second time intervals. The worm movement is recorded
and analyzed with custom software to calculate the average velocity and the percentage of turning and curling. Contrary to some published studies, our results did not show a significant difference compared to control experiments. This suggests that C. elegans may not sense static magnetic fields in the range of field strengths that we tested
Figure 4 from: Pandey TR, Jin X-H (2021) Taxonomic revision of Habenaria josephi group (sect. Diphyllae s.l.) in the Pan-Himalaya. PhytoKeys 175: 109-135. https://doi.org/10.3897/phytokeys.175.59849
No full textFigure 4 Habenaria josephiA habit B floral bract C pedicellate ovary with spur D petal E dorsal sepal F lateral sepal G lip (A photographed from FLPH Expedition 13-0845, PE B–G drawn from the same specimen by T.R. Pandey)
Figure 16 from: Pandey TR, Jin X-H (2021) Taxonomic revision of Habenaria josephi group (sect. Diphyllae s.l.) in the Pan-Himalaya. PhytoKeys 175: 109-135. https://doi.org/10.3897/phytokeys.175.59849
No full textFigure 16 Habenaria szechuanicaA habit B floral bract C pedicellate ovary with spur D petal E dorsal sepal F lateral sepal G lip (A photographed from Hengduan Mountain Team 02687, PE B–G drawn from the same specimen by T.R. Pandey)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Coatings of Bio-based materials on flexible food packaging: opportunities for problem solving and innovations (chapter 13)
No full textA sustainable new economy needs a marked turn in the use of raw materials and resources; if solar and wind power represent the perspective in the energy supply sector, bio-based materials (BBM) and their composites might be the future in the fi eld of new materials (Carus & Scholz, 2010). Every year, using different biosynthetic pathways, nature affords 170 billion metric tons of biomass, but only a small amount (around 3.5%), mainly represented by wood used for conventional applications, is utilized by mankind (Shen et al., 2010). The packaging sector, with food packaging by far its largest part, uses about 250 million tons of different materials and accounts for almost 500 billion dollars worldwide; about one third of that huge amount of material is made up of synthetic plastics (Piergiovanni, 2010). Therefore, the packaging sector represents a signifi cant challenge and an excellent opportunity for reducing dependence on fossil resources and increasing the sustainability of a specifi c fi eld. Anyhow, to accelerate and to make feasible the replacement of the conventional materials with bio-based alternatives, without prompting any confl ict with the packaging lines currently operating within the manufacturing companies, a valuable opportunity is represented by the use of BBM as coatings for common fl exible packaging materials, with the aim of improving properties while reducing the thickness of synthetic plastic fi lms. In this context, after a preliminary review of the existing uses and perspectives of BBM, this chapter fi rstly focuses on the coating technology applications in the fl exible packaging fi eld, then presents some of the experimental work carried out within our research group for the enhancement of useful performance of plastic fi lms for food packaging, through the development of thin layers made of BBMs assembled using different procedure
FIGURE 4 in Indigofera himachalensis (Fabaceae: Indigofereae), a new species from Himachal Pradesh, India
No full textFIGURE 4. Indigofera himachalensis (from Chauhan & Pandey 5011) A. Habit, B. Leaflet (leftside)-abaxial, (rightside)-adaxial C. Standard, D. Wings, E. Keel, F. Calyx with gynoecium, G. Pod, H. Seed. Drawn by V. Chauhan.Published as part of Chauhan, Vibha, Pandey, Arun K. & Schaefer, Hanno, 2013, Indigofera himachalensis (Fabaceae: Indigofereae), a new species from Himachal Pradesh, India, pp. 43-49 in Phytotaxa 112 (2) on page 48, DOI: 10.11646/phytotaxa.112.2.2, http://zenodo.org/record/507885
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