Impact of Sclerotinia Stem Rot on Yield of Canola.

Sclerotinia sclerotiorum is the causal agent of Sclerotinia stem rot (SSR) of canola (Brassica napus). In North Dakota, the leading canola producer in the United States, SSR is an endemic disease. In order to estimate the impact of this disease on canola yield, field experiments were conducted from 2000 to 2004 at several locations in North Dakota and Minnesota. Experimental plots were either inoculated with laboratory-produced ascospores or infected by naturally occurring inoculum in commercial fields. Applying fungicides at different concentrations and timings during the flowering period created epiphytotics of diverse intensities. Disease incidence was measured once prior to harvesting the crop on 50 to 100 plants per plot. Results of the study indicated that 0.5% of the potential yield (equivalent to 12.75 kg/ha) was lost for every unit percentage of SSR incidence (range of 0.18 to 0.96%). Considering the current cost of fungicide applications and the market value of this commodity, a 17% SSR incidence could cause losses similar to the cost of a fungicide application. Additional efforts are required to improve current levels of tolerance of canola plants to this pathogen.

Efficacy of Fungicides for Control of Sclerotinia Stem Rot of Canola.

Sclerotinia stem rot (SSR), incited by Sclerotinia sclerotiorum, causes yield reductions to canola (Brassica napus) grown in North Dakota and Minnesota. Field trials were conducted in North Dakota and Minnesota from 2000 to 2004 to evaluate the effect of foliar fungicides on SSR and canola yield. Levels of SSR varied among years and location. In general, fungicides that consistently reduced SSR incidence compared with an untreated control were azoxystrobin, benomyl, boscalid, iprodione, prothioconazole, tebuconazole, thiophanate-methyl, trifloxystrobin, and vinclozolin. Significant reductions in SSR incidence with fungicides did not always translate into differences in canola yield, however. Inconsistent results were observed with different timings of applications based on percent bloom. This indicates that application timing should be based on factors in addition to percent bloom.

Response of Canola Cultivars to Sclerotinia sclerotiorum in Controlled and Field Environments.

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, can be a devastating disease of canola (Brassica napus) in the northern United States. No canola cultivars are marketed as having resistance to SSR. Field trials were established in Red Lake Falls, MN (2001, 2003, and 2004) and Carrington, ND (2001, 2002, 2003, and 2004) to evaluate canola cultivars for resistance to SSR. These cultivars also were evaluated for resistance to SSR under controlled conditions using the following methods: petiole inoculation technique (PIT), detached leaf assay (DLA), and oxalic acid assay (OAA). Significant (P ≤ 0.05) differences were detected among cultivars for SSR and yield in the field trials, with SSR levels varying from low to high among years and locations. Cultivars with consistent high levels and low levels of SSR in the field trials were identified. Significant (P ≤ 0.05) differences were detected among cultivars for SSR using the PIT and OAA methods, but not the DLA method. No significant (P ≤ 0.05) correlations between SSR levels in the controlled studies with SSR levels in the field trials were detected; however, significant negative correlations were detected between SSR area under the disease process curve values from the PIT method and yield from Carrington, ND in 2001 and 2002. Although the PIT and OAA methods differentiated cultivars, neither method was able to predict the reaction of cultivars to SSR in the field, indicating that field screening for SSR resistance is still critical for the development of resistant cultivars.

The squalestatins: synthesis and biological activity of some C3-modified analogues; replacement of a carboxylic acid or methyl ester with an isoelectronic heterocyclic functionality.

A series of squalestatins modified at the C3-position with a heterocyclic functionality was prepared and evaluated in vitro as inhibitors of squalene synthase (SQS). Structure-activity relationships for compounds with the 4,6-dimethyloctenoate at C6(S1 analogues) were different from those for analogues lacking the C6 ester (H1 analogues), with a greater dependence on the nature of the C3-substituent for the H1 series. Potent SQS inhibitory activity equivalent to that of H1 is retained by a C3-(tetrazol-5-yl) analogue, i.e., a carboxylic acid mimetic. The C3-methyl ester derivative is 10-fold less active than H1, and SQS inhibitory activity similar to that of the methyl ester was retained only in those C3-heterocycle-substituted H1 analogues for which electrostatic potential maps of the C3-substituent were closely similar to that of a methyl ester.

Maurice Ravel's illness: a tragedy of lost creativity.

Maurice Ravel had been subject to psychiatric disorder for many years when signs of organic brain disease appeared at the age of 52. Aphasia, apraxia, agraphia, and alexia became established some five years later. Musical creativity was lost. Alajouanine diagnosed cerebral atrophy with bilateral ventricular enlargement. Though Ravel's condition deteriorated progressively, generalised dementia was not apparent. He died in December 1937, after a craniotomy performed by Clovis Vincent, possibly from a subdural haematoma. Vincent's operative findings are described here. The likely cause of Ravel's illness was a restricted form of cerebral degeneration.

The performance of professional musicians on the seashore measures of musical talent: an unexpected finding.

During an investigation designed to explore the effects of brain lesions on musical ability in professional musicians, the Seashore Scale was used to discover whether focal damage was associated with specific impairment of any of the basic elements of musical talent. In order to obtain adequate control of the experimental group it was necessary to study a comparable group of professional musicians. For this purpose the Seashore test battery was given to 21 orchestral players. The scores obtained by these professionals were better than an estimate of the population values in only three of the six tests, pitch discrimination, rhythm and tonal memory; they were significantly poorer in the test of timbre. This unexpected finding sheds doubt on Seashore's assumptions about the requirements for high musical talent. It also raises questions on the use of the Seashore battery in certain areas of psychological research.

Spinal metastases. A retrospective survey from a general hospital.

One hundred and thirty-one patients presenting to a general hospital with neurological symptoms deriving from spinal metastases were reviewed. The primary site of tumour was the lung in 33 per cent, breast in 28 per cent, other sites in 25 per cent and unknown in 14 per cent. Haematological malignancies were excluded. In 47 per cent of cases the spinal metastasis produced the first evidence of malignant disease. Spinal or radicular pain was the initial complaint in 69 per cent of cases, followed by the appearance of neurological symptoms. Leg weakness usually preceded sphincter disturbance, and was the commonest reason for referral. Spinal cord compression occurred in 106 patients, 10 had compression of conus medullaris or cauda equina and 15 had evidence of radicular compression only. Plain x-rays of the spine were abnormal in 84 per cent of patients, and in 94 per cent of those with carcinoma of the breast. The results of treatment by radiotherapy alone were retrospectively compared with those of surgical decompression (with or without radiotherapy). There was no significant difference between these results for immediate response to treatment or for long-term outcome. The best predictor of outcome was the site of primary tumour. Only 17 per cent of patients with lung cancer responded well to treatment and only 2 per cent were alive one year after treatment; 51 per cent of patients with breast cancer responded well and 36 per cent were alive at one year. Surgical treatment is considered preferable in cases in which the diagnosis of cancer is not proven, when there is a possibility of neural compression by diseased bone rather than soft tumour tissue and when the area has previously been irradiated. These groups accounted for about 60 per cent of our patients. Radiotherapy alone may be preferred if multiple lesions are demonstrated. In other cases a therapeutic decision is required. The availability of neurosurgical and radiotherapeutic facilities will be a factor. There is no clear evidence from our figures or from the literature of a difference between results obtained by radiotherapy alone and those with surgical decompression followed by irradiation. The choice of treatment will depend upon the particular requirements of each individual parent.

Cerebral compression by myeloma.

A patient presented with right hemiparesis, dysphasia and a large, palpable, left frontoparietal mass arising from the calvarial diploe. A diagnosis of multiple myeloma was made on radiological and biochemical grounds, together with bone marrow examination. Few cases of cerebral compression by a massive plasmacytoma have been reported, but in some surgical management produced clinical deterioration. The present case was treated with radiotherapy and chemotherapy, with satisfactory results.

Myopathy due to epsilon amino-caproic acid.

A subacute necrotizing myopathy developed in a patient treated with epsilon amino-caproic acid (EACA) for subarachnoid hemorrhage. The muscle biopsy showed features suggesting that the muscle fiber necrosis might have been due to capillary damage. An attempt to induce EACA myopathy in the rat was made, but no abnormality developed.

Pattern sensitive epilepsy: a case report.

A child with pattern sensitive epilepsy is reported. She had both absences and generalised seizures. The latter occurred spontaneously but the former followed concentration on patterned materials. These self-induced seizures appeared to have an affective component. The EEG showed generalised atypical spike and wave discharges both in the resting state and during intermittent photic and pattern stimulation. The patient responded to sodium valproate.