70 research outputs found
How large should whales be?
The evolution and distribution of species body sizes for terrestrial mammals
is well-explained by a macroevolutionary tradeoff between short-term selective
advantages and long-term extinction risks from increased species body size,
unfolding above the 2g minimum size induced by thermoregulation in air. Here,
we consider whether this same tradeoff, formalized as a constrained
convection-reaction-diffusion system, can also explain the sizes of fully
aquatic mammals, which have not previously been considered. By replacing the
terrestrial minimum with a pelagic one, at roughly 7000g, the terrestrial
mammal tradeoff model accurately predicts, with no tunable parameters, the
observed body masses of all extant cetacean species, including the 175,000,000g
Blue Whale. This strong agreement between theory and data suggests that a
universal macroevolutionary tradeoff governs body size evolution for all
mammals, regardless of their habitat. The dramatic sizes of cetaceans can thus
be attributed mainly to the increased convective heat loss is water, which
shifts the species size distribution upward and pushes its right tail into
ranges inaccessible to terrestrial mammals. Under this macroevolutionary
tradeoff, the largest expected species occurs where the rate at which
smaller-bodied species move up into large-bodied niches approximately equals
the rate at which extinction removes them.Comment: 7 pages, 3 figures, 2 data table
<i>Spitzer</i> microlens measurement of a massive remnant in a well-separated binary
We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having M1 > 1.35 M⊙ (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star (NS) or black hole (BH). The system has a projected separation r⊥ = 6.1 ± 0.4 AU and lies in the Galactic bulge. These measurements are based on the "microlens parallax" effect, i.e., comparing the microlensing light curve as seen from Spitzer, which lay at 1.25 AU projected from Earth, to the light curves from four ground-based surveys, three in the optical and one in the near-infrared. Future adaptive optics imaging of the companion by 30 m class telescopes will yield a much more accurate measurement of the primary mass. This discovery both opens the path and defines the challenges to detecting and characterizing BHs and NSs in wide binaries, with either dark or luminous companions. In particular, we discuss lessons that can be applied to future Spitzer and Kepler K2 microlensing parallax observations
Association between polymorphisms in the adiponectin gene and cardiovascular disease: a meta-analysis
Single nucleotide polymorphism rs3774261 in the AdipoQ gene is associated with the risk of coronary heart disease (CHD) in Northeast Han Chinese population: a case-control study
Contribution to the moss flora of Dereli, Giresun district (Turkey)
Field studies were organised for exploring the moss flora of Dereli district of Giresun during spring-summer period in 2005. Ninety-one specimens were collected in these field studies. After identification of these specimens, five new records for A4 (40-42° N, 38-42° E) were determined according to Henderson's grid system (1961a). © 2008 Akadémiai Kiadó
Lead adsorption capacity of some moss species used for heavy metal analysis
WOS: 000329081100053Mosses, covering about 23,000 species of all land plants in the world, have been widely used as an indicator of heavy metal pollution in many studies. A crucial part in these researches is to regularize the adsorption capacities of different moss species obtained from different regions to objectively compare the pollution levels. In this study, we have first analyzed the lead adsorption capacities of six different moss species by means of using column filled with Amberlite XAD-2000 resin method. The adsorption capacities of the studied six mosses are found in descending order as Eurhynchium striatum, Hypnum cupressiforme, Pleurozium schreberi, Eurhynchium striatulum, Homalothecium sericeum and Thuidium tamariscinum. Then, we have regularized the Pb adsorption levels for the moss species obtained from different regions along one of the important coast highway in Turkey, namely Sarp-Samsun highway, with respect to the determined adsorption capacities. (C) 2013 Elsevier Ltd. All rights reserved
Heavy metal analysis around Murgul (Artvin) copper mining area of Turkey using moss and soil
Akbulut, Songul/0000-0001-8025-2141WOS: 000303788000003This research investigates heavy metal pollution around one of the most important mining areas in Turkey, the Murgul mining, by means of analyzing moss and soil samples collected in the neighborhood of the copper mining at different distances. Energy dispersive X-ray fluorescence (EDXRF) spectrometry (Epsilon 5, PANalytical, Almelo, The Netherlands) is utilized in the experiments. The results have indicated that the both moss and soil samples contain Aluminum, Vanadium, Chromium, Manganese, Iron, Nickel, Copper, Zinc, Arsenic and Lead. The comparison of the heavy metal concentrations with the typical measurements in the world and with the limit values for the human health has revealed the critical heavy metal pollution levels in the region, where one of Turkey's first environmental spills was also observed. The possible consequences of these results are briefly discussed from the point of potential hazards to ecology and human health. (C) 2012 Elsevier Ltd. All rights reserved
EFFECTS OF RUN TRAINING ON BONE DEVELOPMENT AND BONE MINERALIZATION IN GROWING MICE
We planned to study the body weights, bone sizes and bone mineral (Ca, Mg, Zn) contents of growing mice subjected to treadmill training. Twelve 4-week-old male Swiss Albino mice were divided into sedentary and exercise groups. The mice were trained by running exercise on a flat bed treadmill with 15 m/min, 30 min/day motion, throughout 5 days per week, for 12 weeks. The body weight of animals, and length, fat-free dry weight and Ca, Mg, and Zn contents of bones were measured in both groups. Body weights of animals, and lengths and wet and dry weights of the femur and the tibia were significantly higher in the exercised group. Also, the Zn, Mg and Ca mineral contents of bones in the group that underwent exercise were higher than in the other group. Running exercise with a flat bed treadmill performed by the growing mice is an effective exercise mode, especially for bone morphology
Grimmia ramondii (Grimmiaceae, Bryopsida) for the second time recorded in Turkey and southwestern Asia
Grimmia ramondii (Lam and DC.) Margad (Grimmiaceae) is recorded for the second time in Turkey. Additionally it is new to southwestern Asia with the exception of Turkey. The specimen was collected during a botanical field trip in the Hatila Valley National Park (Artvin-Turkey) in 2006. Illustrated descriptions of the species along with a short note on the species and its distribution in and outside Turkey are provided. © 2008 Asian Network for Scientific Information
Synthesis and properties of alkyl chain substituted naphthalenetetracarboxylic monoanhydride monoimides and unsymmetrically substituted naphthalene derivatives
1,4,5,8-Naphthalenedianhydride is converted to N-(2-ethylhexyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2a) and N-(2-hydroxyethyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2c) through the potassium salt prepared from a reaction with potassium hydroxide. N-Dodecyl-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2b) was prepared by the condensation reaction of 1,4,5,8-naphthalenedianhydride with dodecylamine. Naphthalene-1,4-N-(2-ethylhexyl)-imide-N-ethyl-1H-benzo[d]imidazol-5-carboxylate and naphthalene-1,4-N-dodecyl-imide-N-ethyl-1H-benzo[d]imidazol-5-carboxylate were prepared by the condensation reaction of N-alkyl-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (alkyl = 2-ethylhexyl and dodecyl) with ethyl 3,4-diaminobenzoate. Molecular structures and electrochemical properties of all naphthalene derivatives were determined. Their thermal properties were also studied by thermal gravimetric analysis. © 2016, Chemical Publishing Co. All rights reserved
- …