Guidelines for treatment of lice in sheep with long wool based on a model of the development of wool damage.

Objective: This study used a model of the development of wool damage caused by lice in long wool to examine the conditions under which treatment of the sheep is advisable on an economic basis.

Methods: The model uses the proportion of a flock showing visible signs of rubbing and the number of days until the next shearing to compare the cost of treatment (product plus labour) with production losses because of the reduction in wool value caused by lice. From the model output, guidelines are provided to inform producers of the most cost-effective option for lice control.

Oncostatin M regulates neural precursor activity in the adult brain.

The regulation of neural precursor cell (NPC) activity is the major determinant of the rate of neuronal production in neurogenic regions of the adult brain. Here, we show that Oncostatin M (Osm) and its receptor, OsmRβ, are both expressed in the subventricular zone (SVZ) and that in contradistinction to leukemia inhibitory factor and ciliary neutrophic factor, Osm directly inhibits the proliferation of adult NPCs as measured by a decreased level of neurosphere formation in vitro. Similarly, intraventricular infusion of Osm dramatically decreases the pool of NPCs in both the SVZ and the hippocampus.

Regulating compassion: an overview of Canada's federal medical cannabis policy and practice.

Background: In response to a number of court challenges brought forth by Canadian patients who demonstrated that they benefited from the use of medicinal cannabis but remained vulnerable to arrest and persecution as a result of its status as a controlled substance, in 1999 Canada became the second nation in the world to initiate a centralized medicinal cannabis program. Over its six years of existence, this controversial program has been found unconstitutional by a number of courts, and has faced criticism from the medical establishment, law enforcement, as well as the patient/participants themselves.

Methods: This critical policy analysis is an evidence-based review of court decisions, government records, relevant studies and Access to Information Act data related to the three main facets of Health Canada's medicinal cannabis policy--the Marihuana Medical Access Division (MMAD); the Canadians Institute of Health Research Medical Marijuana Research Program; and the federal cannabis production and distribution program.

Disseminated haemangioblastoma without evidence of the von Hippel-Lindau syndrome or haemangioblastomatosis--A case report and clinico-pathological correlation.

A 71-year-old Caucasian female presented to our service with disseminated cranial and spinal haemangioblastomata but no other features to suggest the von Hippel-Lindau syndrome. We feel that this represents cellular dissemination through the cerebro-spinal fluid and may be an intermediate step to the development of frank haemangioblastomatosis. By comparing this presentation to that of other tumours we have suggested a potential pathological mechanism and have discussed its management.

Convective roll dynamics in liquid 4He near the onset of convection.

We present results of experiments on Rayleigh-Bénard convection in liquid 4He at several temperatures. We show visually that with carefully defined boundary conditions the basic convection state consists of parallel rolls which are aligned in one of two directions, the angle thus defined as being temperature dependent and we attempt to explain this behavior. We also show directly the skew-varicose instability acting on the basic state and correlate it with fluctuations in the temperature difference across the fluid layer.

Flow pattern dynamics in convecting liquid helium.

We present experimental data which correlate thermal measurements and flow visualization in convecting liquid 4He. For a small range R(C)R1, generating thermal oscillations as in earlier reports.