125 research outputs found
Delineating origins of cheetah cubs in the illegal wildlife trade: Improvements based on the use of hair δ18O measurements
All African felids are listed as vulnerable or endangered according to the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. Cheetahs (Acinonyx jubatus) in particular have declined rapidly as a result of human impacts so that development of effective strategies and tools for conservation of this highly vulnerable species, as well as African felids in general, are essential for their survival in the wild. Here we use the oxygen stable isotopic compositions of cheetah hair to determine origins of cheetah cubs destined for the illegal exotic pet trade by associating individual cubs with predicted δ18O isoscape locations. We found that cheetah cubs most likely originated in East Africa, close to the corridors responsible for this aspect of the illegal wildlife trade to the Middle East. Further refinement of these assignments using a two isotope analysis (δ18O and δ13C values) indicate that these cubs were likely sourced in Southern Ethiopia or possibly as far as Tanzania. We also demonstrate that δ18O values in tissues can provide provenance information in cases where results of δ2H analyses may be obscured by the effects of metabolic routing of nutrients during nursing, starvation, or dehydration. This study demonstrates the utility of stable isotopic tools for conservation and forensic uses for endangered mammalian species
Dynamics of gelling liquids: a short survey
The dynamics of randomly crosslinked liquids is addressed via a Rouse- and a
Zimm-type model with crosslink statistics taken either from bond percolation or
Erdoes-Renyi random graphs. While the Rouse-type model isolates the effects of
the random connectivity on the dynamics of molecular clusters, the Zimm-type
model also accounts for hydrodynamic interactions on a preaveraged level. The
incoherent intermediate scattering function is computed in thermal equilibrium,
its critical behaviour near the sol-gel transition is analysed and related to
the scaling of cluster diffusion constants at the critical point. Second,
non-equilibrium dynamics is studied by looking at stress relaxation in a simple
shear flow. Anomalous stress relaxation and critical rheological properties are
derived. Some of the results contradict long-standing scaling arguments, which
are shown to be flawed by inconsistencies.Comment: 21 pages, 3 figures; Dedicated to Lothar Schaefer on the occasion of
his 60th birthday; Changes: added comments on the gel phase and some
reference
Single-incision laparoscopic sterilization of the cheetah (Acinonyx jubatus)
OBJECTIVE : To describe laparoscopic ovariectomy and salpingectomy in the cheetah (Acinonyx jubatus) using single-incision
laparoscopic surgery (SILS).
STUDY DESIGN : Prospective cohort.
ANIMALS : Female cheetahs (Acinonyx jubatus) ( n ¼ 21).
METHODS : Cheetahs were randomly divided to receive either ovariectomy (n ¼ 11) or salpingectomy (n ¼ 10). The use and
complications of a SILS port was evaluated in all of cheetahs. Surgery duration and insufflation volumes of carbon dioxide
(CO2) were recorded and compared across procedures.
RESULTS : Laparoscopic ovariectomy and salpingectomy were performed without complications using a SILS port. The
poorly-developed mesosalpinx and ovarian bursa facilitated access to the uterine tube for salpingectomy in the cheetah. The
median surgery duration for ovariectomy was 24 minutes (interquartile range 3) and for salpingectomy was 19.5 minutes
(interquartile range 3) (P ¼.005). The median volume of CO2 used for ovariectomy was 11.25 L (interquartile range
3.08) and for salpingectomy was 4.90 L (interquartile range 2.52), (P ¼.001)
CONCLUSIONS : Laparoscopic ovariectomy and salpingectomy can be performed in the cheetah using SILS without perioperative
complications. Salpingectomy is faster than ovariectomy and requires less total CO2 for insufflation.NRF grants, AfriCat. Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa and the Arabella Dean
fund of the South African Veterinary Foundation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1532-950X2016-07-30hb2015ab201
Ultra-Fast Oleophobic-Hydrophilic Switching Surfaces for Anti-Fogging, Self-Cleaning, and Oil-Water Separation
Smooth copolymer–fluorosurfactant complex film surfaces are found to exhibit fast oleophobic–hydrophilic switching behavior. Equilibration of the high oil contact angle (hexadecane = 80°) and low water contact angle (110°), which, when combined with the inherent ultrafast switching speed, yields oil–water mixture separation efficiencies exceeding 98%
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