Sensitivity analysis of optimal operation of irrigation supply systems with water quality considerations

A model for optimal operation of water supply/irrigation systems of various water quality sources, with treatment plants, multiple water quality conservative factors, and dilution junctions is presented. The objective function includes water cost at the sources, water conveyance costs which account for the hydraulics of the network indirectly, water treatment cost, and yield reduction costs of irrigated crops due to irrigation with poor quality water. The model can be used for systems with supply by canals as well as pipes, which serve both drinking water demands of urban/rural consumers and field irrigation requirements. The general nonlinear optimization problem has been simplified by decomposing it to a problem with linear constraints and nonlinear objective function. This problem is solved using the projected gradient method. The method is demonstrated for a regional water supply system in southern Israel that contains 39 pipes, 37 nodes, 11 sources, 10 agricultural consumers, and 4 domestic consumers. The optimal operation solution is described by discharge and salinity values for all pipes of the network. Sensitivity of the optimal solution to changes in the parameters is examined. The solution was found to be sensitive to the upper limit on drinking water quality, with total cost being reduced by 5% as the upper limit increases from 260 to 600 mg Cl l^–1. The effect of income from unit crop yield is more pronounced. An increase of income by a factor of 20 results in an increase of the total cost by a factor of 3, thus encouraging more use of fresh water as long as the marginal cost of water supply is smaller than the marginal decrease in yield loss. The effect of conveyance cost becomes more pronounced as its cost increases. An increase by a factor of 100 results in an increase of the total cost by about 14%. The network studied has a long pipe that connects two distinct parts of the network and permits the supply of fresh water from one part to the other. Increasing the maximum permitted discharge in this pipe from 0 to 200 m³ h^–1 reduces the total cost by 11%. Increasing the maximum discharge at one of the sources from 90 to 300 m³ h^–1 reduces the total cost by about 8%.     

Cryopreservation of Ram Semen in Extenders Containing Soybean Lecithin as Cryoprotectant and Hyaluronic Acid as Antioxidant

A soybean lecithin‐based extender supplemented with hyaluronic acid (HA) was assayed for effectiveness to improve the quality of frozen–thawed ram semen. HA has not been tested yet in an extender containing soybean lecithin for freezing ram semen. Thus, the aim of this study was to analyse the effects of soybean lecithin at 1% or 1.5% along with HA at 0, 0.5 and 1 mg ml^‐1 in a Tris‐based extender on the motion characteristics, membrane integrity (HOST), viability, GSH peroxidase (GSH‐PX) activity, lipid peroxidation and acrosomal status after freezing–thawing. Semen was collected from four Mehraban rams during the breeding season and frozen in the six lecithin×HA extenders. The extender containing 1.5% lecithin supplemented with no HA yielded higher total motility (52.5%±1.6), viability (55.8%±1.6) and membrane integrity (44.5%±1.7), but the effects of the lecithin concentration did not reach signification. Linearity‐related parameters, ALH, BCF, lipid peroxidation, GSH‐PX activity, morphology and acrosomal status were not affected by the extender composition. In general, adding HA significantly decreased sperm velocity (1 mg ml^‐1 HA), total motility (only with 1.5% lecithin), viability (1 mg ml^‐1 HA for 1% lecithin; both concentrations for 1.5% lecithin) and membrane integrity. In conclusion, adding HA to the freezing extender supplemented with soybean lecithin failed to improve quality‐related variables in ram semen. Increasing the lecithin content could have a positive effect, but further studies are needed.     

Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.     

Superradiance in a torus magnetosphere around a black hole

The coalescence of a neutron star and a black hole in a binary system is believed to form a torus around a Kerr black hole. A similarly shaped magnetosphere then results from the remnant magnetic field of the neutron star. In the strong-field case, it contains a cavity for plasma waves located between the barrier of the gravitational potential and the surrounding torus. This cavity may be unstable to superradiance of electromagnetic waves. Superradiant amplification of such waves, initially excited by turbulence in the torus, should inflate into a bubble in a time as short as approximately 0.75 (1 percent/&cjs3539;epsilon&cjs3539;2)(M/7M middle dot in circle) seconds approximately 0.15 to 1.5 seconds, assuming an efficiency &cjs3539;epsilon&cjs3539;2 = 0.5 to 5 percent and a mass M = 7M middle dot in circle. These bubbles may burst and repeat, of possible relevance to intermittency in cosmological gamma-ray bursts. The model predicts gamma-ray bursts to be anticorrelated with their gravitational wave emissions.     

Cholesterol and triglyceride reduction in rats fed Matthiola incana seed oil rich in (n-3) fatty acids

Seeds of Matthiola incana contain oil rich (55-65%) in (n-3) linolenic acid. Selected lines were developed and evaluated for their agronomic and chemical parameters. Extracted oil was fed for 6 weeks to rats, which were compared with rats fed a diet containing coconut oil or sunflower oil. Cholesterol levels were significantly lowest in rats fed diets rich in M. incana oil (27% reduction), and triglycerides were significantly lower in rats receiving either M. incana or sunflower oil (36% reduction). The contents of arachidonic acid and other (n-6) fatty acids were significantly the lowest in the liver and plasma of rats that had received M. incana oil. The levels of (n-3) fatty acids were significantly greater in both the liver and plasma of rats fed M. incana oil. The ratio of (n-3)/(n-6) long-chain fatty acids in the plasma was 7 times higher in rats fed with M. incana oil than in those fed with sunflower oil and 6 times higher than in those fed coconut oil. The results demonstrate for the first time a beneficial effect of dietary M. incana oil in reducing cholesterol levels and increasing (n-3) fatty acid levels in the plasma. This new, terrestrial plant source of (n-3) fatty acids could replace marine oils and thereby contribute beneficially to the human diet.     

Spontaneous intradural disc herniation with focal distension of the subarachnoid space in a dog

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13–L1 disc space. T12–L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding.     

A method for intervertebral space distraction before stabilization combined with complete ventral slot for treatment of disc-associated wobbler syndrome in dogs

Objective— To evaluate the use of a modified K-wire spacer for maintaining intervertebral distraction after ventral decompression and during stabilization as a treatment for disc-associated wobbler syndrome in large breed dogs.
Study Design— A retrospective study.
Animals— Dogs (n=7) with disc-associated wobbler syndrome.
Methods— Medical records (2003–2006) of dogs treated by a modified surgical method were evaluated. Data retrieved were signalment, onset and duration of clinical signs, neurologic abnormalities, diagnostic methods, surgical procedure, immediate, and long-term (≥1 year) postoperative clinical and radiographic outcome.
Results— Mean duration of clinical signs was 4.8 months. Neurologic signs included ataxia (2), ambulatory tetraparesis (2), and non-ambulatory tetraparesis (3). Three dogs had disc protrusion in 2 sites, 2 dogs had the procedure in 1 location and stabilization of both affected sites. All dogs improved dramatically and remained for 1–3 years. One dog had recurrence of cervical discomfort 13 months later.
Conclusions— Despite the limited number of dogs, overall initial successful outcome with only 1 dog having mild recurrence 13 months later supports further use and evaluation of this technique.
Clinical Relevance— Distraction using a K-wire spacer after ventral decompression followed by stabilization should be considered in dogs with disc-associated wobbler syndrome to prevent collapse of the intervertebral space.