The toxic sheep collar for control of sheep-killing coyotes: A progress report

The toxic sheep collar is the most selective method known for killing coyotes that prey on domestic sheep. The concept dates back to the early 1900's and has been studied at the Denver Wildlife Research Center (DWRC) since 1974. Field tests with sodium cyanide (NaCN) in 1975 were unsuccessful due to repellent properties of the toxicant and to the apparent reluctance of coyotes to attack tethered lambs wearing bulky collars. Coyotes attacked one or more tethered, collared lambs in 7 of the 19 test pastures. In all, 14 collared lambs were attacked. Eight of the collars were punctured but no dead coyotes were recovered. A smaller collar containing diphacinone was field tested in 1976. The diphacinone-filled collars were readily accepted by coyotes and lethal to them, but the slow action (5-16 days between dosing and death) of diphacinone made it difficult to assess the effectiveness of these collars under field conditions. Target flocks containing 1 to 12 collared lambs plus uncollared ewes were placed in 15 fenced pastures from which the larger ranch flocks had been removed after repeated coyote predation. One or more collared lambs were attacked in 11 of the 15 tests. An unknown number of coyotes were killed, and in most tests the subsequent incidence of predation was lower than that before the test. Captive coyotes continued to kill sheep for 4 or 5 days after they received a lethal dose of diphacinone; therefore a faster-acting toxicant is needed. This research has shown that problem coyotes can be killed with toxic collars, but further studies are needed to determine the feasibility of this approach compared with traditional means of control. In most tests to date the frequency of coyote predation has been too low and too irregular to permit effective use of the collar; target flocks were in the field for an average of 10 days before being attacked. The known disadvantages of the method include the need to sacrifice live lambs, the human hazards associated with the use of toxicants under field conditions, and the costs of managing target flocks and other sheep in the problem areas

COYOTES, SHEEP AND LITHIUM CHLORIDE

The use of LiCl-treated baits and carcasses has been advocated as a means of controlling coyote predation on sheep through a process known as aversive conditioning or taste aversion. While some investigators have made well publicized claims of damage reduction through the use of LiCl on sheep ranges, other researchers have experienced difficulty establishing prey aversion in captive coyotes. The conflicting results suggest a need for extensive, carefully controlled research in both pen and field situations before valid conclusions can be reached regarding aversive conditioning as a depredations control method

COYOTES, SHEEP AND LITHIUM CHLORIDE

The use of LiCl-treated baits and carcasses has been advocated as a means of controlling coyote predation on sheep through a process known as aversive conditioning or taste aversion. While some investigators have made well publicized claims of damage reduction through the use of LiCl on sheep ranges, other researchers have experienced difficulty establishing prey aversion in captive coyotes. The conflicting results suggest a need for extensive, carefully controlled research in both pen and field situations before valid conclusions can be reached regarding aversive conditioning as a depredations control method

Chondrules and Opaque Phases in Unequilibrated R Chondrites: A Comprehensive Assessment of Their Formation

Equilibrated Rumuruti (R) chondrites record an oxygen fugacity between 0 and 3.5 log units below the fayalite-magnetite-quartz buffer, and a sulfur fugacity (fS2) 2 log units above the iron-troilite buffer. They are more than an order of magnitude more oxidized than the ordinary chondrites [1], and orders of magnitude more sulfidized than solar values. Although the R chondrites have the highest (delta)O-17 value of any meteorites, analyses of unequilibrated R chondrites indicate chondrule formation in an oxygen isotope reservoir similar to that of the ordinary chondrite chondrules. We present the relationship of the R chondrite parent body to pre-accretionary volatiles O and S based on our analyses of unequilibrated R chondrite material in two thin sections from the meteorite Mount Prestrud (PRE) 95404

Meteoritic Evidence for a Ceres-sized Water-rich Carbonaceous Chondrite Parent Asteroid

Carbonaceous chondrite meteorites record the earliest stages of Solar System geo-logical activities and provide insight into their parent bodies\u27 histories. Some carbonaceous chondrites are volumetrically dominated by hydrated minerals, providing evidence for low temperature and pressure aqueous alteration1. Others are dominated by anhydrous minerals and textures that indicate high temperature metamorphism in the absence of aqueous fluids1. Evidence of hydrous metamorphism at intermediate pressures and temperatures in carbonaceous chondrite parent bodies has been virtually absent. Here we show that an ungrouped, aqueously altered carbonaceous chondrite fragment (numbered 202) from the Almahata Sitta (AhS) meteorite contains an assemblage of minerals, including amphibole, that reflect fluid-assisted metamorphism at intermediate temperatures and pressures on the parent asteroid. Amphiboles are rare in carbonaceous chondrites, having only been identified previously as a trace component in Allende (CV3oxA) chondrules2. Formation of these minerals requires prolonged metamorphism in a large (~640-1800 km diameter), unknown asteroid. Because Allende and AhS 202 represent different asteroidal parent bodies, intermediate conditions may have been more widespread in the early Solar System than recognized from known carbonaceous chondrite meteorites, which are likely a biased sampling

A Unique Amphibole- and Magnetite-Rich Carbonaceous Chondrite from Almahata Sitta

Almahata Sitta (AhS) 202 from the UoK collection represents a clast from the polymict breccia asteroid 2008 TC3. AhS 202 was recognized as a unique carbonaceous chondrite (CC) with a high magnetite content. Here we report that it also contains a significant amount of amphibole, a mineral that is very rare in chondrites and has not previously been reported in significant abundance in a CC. We present new petrographic, oxygen isotope, and micro-FTIR data. We discuss petrogenesis and possible relationships to known CC

On the possible role of elemental carbon in the formation of reduced chondrules

Recent experiments have been designed to produce chondrule textures via flash melting while simultaneously studying the nature of chondrule precursors. However, these experiments have only been concerned with silicate starting material. This is a preliminary report concerning what effects elemental carbon, when added to the silicate starting material, has on the origin of chondrules produced by flash melting

In-situ Discovery of a Cluster of Refractory Grains in an Allende Ferromagnesian Chondrule

During our nano-mineralogy investigation of the Allende meteorite, we discovered a unique corundum-rich cluster of irregular micrometer-sized refractory grains in a type IA chondrule. The presence of relatively oxidized (rutile) and highly reduced (a new mineral Ti_2O_3, khamrabaevite) phases in the same cluster reflects distinctly different environments prior to incorporation of the cluster into the chondrule. To our knowledge, this is the first occurrence of such a cluster. Investigation of phases that are clearly exotic to the host chondrule and may predate its formation can provide not only important constraints on the materials present when chondrules formed and the enviroments within or outside the Protoplanetary disk, but also on the chondrule formation event. Herein we report our prelimary results on the mineralogy of these grains and the overall petrology of their host chondrule

Automatic Correction of the 3D Orientation of the Brain Imagery

Classification of human brain pathologies can be guided by the estimation of the departure of 3D internal structures from the normal bilateral symmetry. However symmetry based analysis can 't be precisely carried out when the 3D brain orientation is misaligned, a common occurrence in clinical practice. In this paper, a technique to automatically identify the symmetry plane and correct the 3D orientation of volumetric brain images in a cost effective way is developed. The algorithm seeks the best sampling strategies to realign 3D volumetric representation of the brain within scanner coordinate system. The inertia matrix is computed on the sampled brain, and the principle axes are derived from the eigen vectors of the inertia matrix. The technique is demonstrated on MR and CT brain images and the detected symmetry plane that is orthogonal to the principle vectors is provided. A spatial affine transform is applied to rotate the 3D brain images and align them within the coordinate system of the scanner. The corrected brain volume is re-sliced such that each planar image represents the brain at the same axial level