Much remains to be learned about how anthropogenic structures affect migration in large mammals. We examined the potential influence of the international railroad in Mongolia on migration in Mongolian gazelles (Procapra gutturosa). We examined gazelle movements and the normalized difference vegetation index (NDVI) on both sides of the railroad. The tracked gazelles never crossed the railroad, despite movements that mainly followed the railroad in winter and higher NDVI values on the opposite side. It is likely that the railroad had a barrier effect on gazelle migration because it split the gazelles' habitat. Our results, although based on an extremely small sample, have utility in indicating approaches that might be useful for examining migration in ungulates.Resumen: Falta mucho por conocer sobre el efecto de estructuras antropogénicas sobre la migración de mamíferos mayores. Examinamos la potencial influencia del ferrocarril internacional en Mongolia sobre la migración de gacelas de Mongolia ( Procapra gutturosa). Examinamos los movimientos de las gacelas y eĺ ındice de vegetación de diferencia normalizada (IVDN) a ambos lados de la vía férrea. Las gacelas rastreadas nunca cruzaron la vía férrea, a pesar de que los movimientos mayormente seguían la vía en invierno y que los valores de IVDN eran mayores del lado contrario. Es probable que la vía férrea produjera un efecto de barrera sobre la migración de las gacelas porque dividió al hábitat de las gacelas. Nuestros resultados, aunque basados en una muestra extremadamente pequeña, sonútiles para señalar estrategias que pueden ser utilizadas provechosamente para examinar la migración de ungulados.
The location performance of a global positioning system (GPS) collar was assessed for different habitats and geographical areas. We tested the effects of habitat features, antenna position, movement, and fix interval on location performance around Mount Fuji, a single peak surrounded by wide and flat areas. Fix rate decreased from 100% in open flat areas to 53% under sloped dense canopy. The openness (the actual available sky, i.e., the percentage of a radio collar exposed to the sky when part of the collar is blocked due to terrain and vegetation) and canopy closure affected location accuracy and most other performance parameters. All nine habitat features except for available sky (theoretical, due to terrain) influenced location time. Any combination of obstructions between collar and satellite decreased the available number of satellites, the fix rate, increased the location time, and resulted in poorer location (higher DOP, lower 3-D proportion, or greater location error). A horizontal antenna yielded poorer location performance than a vertical one in the forest but not in the open area.Location performance always decreased when moving in forest rather than in open areas. Location performance changed with fix interval. Sixty-minute intervals resulted in a longer location time and a lower DOP than 10-min intervals. Vegetation affected location performance more than topography in the Mount Fuji area. Factors that cause a longer location time will shorten battery life. We suggest that location frequency and duration employed for field research should be decided by considering the aim of the study and the effects of habitat features, animal activity, and fix interval on GPS performance and battery longevity. The strengthened effect of canopy closure during windy weather should be considered for forest-dwelling animals.
A simple two-step approach has been
employed to synthesize a cobalt–nickel–copper
ternary metal oxide, involving electrochemical precipitation/deposition
followed by calcination. The ternary metal hydroxide gets precipitated/deposited
from a nitrate bath at the cathode in the catholyte chamber of a two-compartment
diaphragm cell at room temperature having a pH ≈ 3. The microstructure
of the ternary hydroxides was modified in situ by two different surfactants
such as cetyltrimethylammonium bromide and dodecyltrimethylammonium
bromide in the bath aiming for enhanced storage performance in the
electrochemical devices. The effect of the surfactant produces a transition
from microspheres to nanosheets, and the effect of micelle concentration
produces nanospheres at a higher ion concentration. The ternary hydroxides
were calcined at 300 °C to obtain the desired ternary mixed oxide
materials as the electrode for hybrid supercapacitors. X-ray diffraction
analysis confirmed the formation of the ternary metal oxide product.
The scanning electron microscopy images associated with energy-dispersive
analysis suggest the formation of a nanostructured porous composite.
Ternary metal oxide in the absence and presence of a surfactant served
as the cathode and activated carbon served as the anode for supercapacitor
application. DTAB-added metal oxide showed 95.1% capacitance retention
after 1000 cycles, achieving 188 F/g at a current density of 0.1 A/g,
and thereafter stable until 5000 cycles, inferring that more transition
metals in the oxide along with suitable surfactants at an appropriate
micellar concentration may be better for redox reactions and achieving
higher electrical conductivity and smaller charge transfer resistance.
The role of various metal cations and surfactants as additives in
the electrolytic bath has been discussed.
Herein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes.
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