Editorial stance on duplicate and salami publication

In this edition of the British Orthoptic Journal the notice to contributors has been amended. The sentence ‘Papers are considered for publication on the understanding that they are not being submitted elsewhere at the same time’ has been extended to address the problem of duplicate publication and now appears under ‘Terms of submission’

Sixty yet still active!

The British Orthoptic Society published the first British Orthoptic Journal in 1939, the second appeared in 1944 then, with the exception of 1946, annually. In the first copy of the British Orthoptic Journal the editorial outlines the events leading up to the formation of the British Orthoptic Society, and this and the subsequent history of the Society is described in the 1987 editorial, the year of the Society’s Golden Jubilee. In the president’s letter published in that first edition, Mary Maddox wrote: ‘This journal will afford a method of recording the progress of orthoptics.

Ocular sequelae from the illicit use of class A drugs

Aim: To highlight the changes that may take place in the visual system of the class A drug abuser. Methods: A literature review was carried out of ocular/visual sequelae of the more common class A drugs. These include stimulants (cocaine and crack cocaine), narcotics (heroin, morphine, methadone) and hallucinogenics (ecstasy, lysergic acid diethylamide, magic mushrooms, mescaline, phencyclidine). Results: Ocular sequelae affecting visual acuity, the eye and its adnexa, ocular posture and ocular motility can result from recreational use of these drug(s). Conclusions: Awareness of the consequences of illicit drug use should lead to more pertinent questioning during history-taking

Heroin and diplopia

Aims: To describe the eye misalignments that occur during heroin use and heroin detoxification and to give an overview of the management of persisting diplopia (double vision) which results from eye misalignment. Methods: A literature review using Medline and the search terms strabismus, heroin and substance withdrawal syndrome is presented. General management of cases presenting to the ophthalmologist and orthoptist with acute acquired concomitant esotropia is described. Findings: A tendency towards a divergence of the visual axes appears to be present in heroin users, although when present it may not always lead to diplopia. Following detoxification intermittent esotropia or constant esotropia (convergence of the visual axes) can occur; if intermittent the angle tends to be small and diplopia present when viewing distance objects. Occlusion of one eye to eliminate the second image could encourage the development of a constant deviation. The deviation is not caused by a cranial nerve palsy. Constant deviations of this type are classified as 'acute acquired concomitant esotropia'. Relief from the diplopia may be gained by prismatic correction, and the deviation may then resolve spontaneously. Botulinum toxin or surgical intervention may be necessary in cases that do not resolve. Conclusions: Heroin use may lead to intermittent or constant exotropia and withdrawal may result in intermittent or constant esotropia. Awareness of the mechanism causing this may avoid referral to other specialties (e.g. neurology) and awareness of treatment modalities could encourage patients to seek appropriate help for relief of symptoms

The use of gross and net margins in the economic analysis of organic farms

This paper was presented at the UK organic research 2002 of the Colloquium of Organic Researchers (COR). In order to assess the technical and economic efficiency of conventional farm businesses a variety of management techniques have been developed. These include gross and net margin analysis and full cost accounting. This paper reviews their effectiveness in organic farming systems and finds that all of the techniques can be useful in helping to assess the economic efficiency of individual enterprises within an organic farming business, although they have their limitations. Organic systems require the integration of a number of usually complementary enterprises and therefore gross and net margins for particular enterprises taken out of the rotational or whole farm context can be misleading. Consequently it is important that any economic investigation of an organic system also includes whole farm economic analysis

Minimising latency of pitch detection algorithms for live vocals on low-cost hardware

A pitch estimation device was proposed for live vocals to output appropriate pitch data through the musical instrument digital interface (MIDI). The intention was to ideally achieve unnoticeable latency while maintaining estimation accuracy. The projected target platform was low-cost, standalone hardware based around a microcontroller such as the Microchip PIC series. This study investigated, optimised and compared the performance of suitable algorithms for this application. Performance was determined by two key factors: accuracy and latency. Many papers have been published over the past six decades assessing and comparing the accuracy of pitch detection algorithms on various signals, including vocals. However, very little information is available concerning the latency of pitch detection algorithms and methods with which this can be minimised. Real-time audio introduces a further latency challenge that is sparsely studied, minimising the length of sampled audio required by the algorithms in order to reduce overall total latency. Thorough testing was undertaken in order to determine the best-performing algorithm and optimal parameter combination. Software modifications were implemented to facilitate accurate, repeatable, automated testing in order to build a comprehensive set of results encompassing a wide range of test conditions. The results revealed that the infinite-peak-clipping autocorrelation function (IACF) performed better than the other autocorrelation functions tested and also identified ideal parameter values or value ranges to provide the optimal latency/accuracy balance. Although the results were encouraging, testing highlighted some fundamental issues with vocal pitch detection. Potential solutions are proposed for further development

Economics of Organic Top Fruit Production (OF0305)

Of all the organic food sectors in the UK, top fruit is one of the least developed. Despite strong consumer demand and high prices for organic fruit there are, at present, only a handful of commercial organic dessert apple and pear growers. One of the barriers to conventional growers converting to organic production has been the lack of robust data on the economics of organic fruit growing. Therefore the overall aim of this study and benefit to the sector was the collection and assessment of economic data from commercial organic top fruit (dessert apples and pears) farms for three seasons (2001-2003) in order to determine its economic feasibility. Data was collected from fruit growers and processed according to Farm Business Survey techniques and was also analysed on a pence per kg basis, a full cost accounting technique developed for analysing top fruit crops. Over the past few years there has been a rapid growth of both the market for organic top fruit, and an increase in the area of land converted to organic top fruit production, although much of the latter has been of older cider orchards. The market for organic top fruit, with a retail value of £67 million and 7% share, is one of the largest organic product groups in the organic market. In 2003, 1187 hectares of organic top fruit were grown, with an estimated retail value of £6.7 million. UK-produced organic top fruit supplies 10% of the market, with the remainder being imported, compared with 21% in the conventional sector. Although growers had previously been reluctant to convert to organic production due to the high costs of conversion, a small number responded in the late 1990’s to the higher prices achievable, supermarket pressure, and to the increasing level of government subsidies available. The on-farm economics of organic apples and pears was largely determined by the level of yields of fruit for the fresh market, prices and costs of production. The greatest variation in income from individual orchards, varieties, farms, and years was caused by differences in the total yield and the proportion of the yield, known as ‘gradeout’ in the fruit industry, which reached Class I & II (this was typically 50-65% for apples and 50-85% for pears). Prices were relatively stable. Yield variations were caused by the UK climate, with its variable spring and summer weather pattern, the weather also indirectly affected yields through its influence on pest and disease levels, especially in 2002. Organic apple yields were found to be 50-80%, and pears 25-55% of those in conventionally managed orchards. Many of the surveyed orchards contained a large proportion of varieties such as Cox, which are less suitable for organic production systems. Only 20% of the varieties in the survey farms had been specifically planted for organic purposes. Where fruit was processed into juice and bottled on the farm, this proved a very valuable way of maintaining total farm income. Across the various farms costs were fairly similar. The largest proportion of costs, were for marketing (30%) and overhead costs (44% -other labour, machinery, rent, orchard depreciation and general fixed costs). Top fruit growing is very labour intensive and labour accounted for 30% of on-farm costs. Total organic costs per hectare were similar to conventional ones. Average net margins for apples (£455/ha, 5p/kg) gave a 7% margin over costs, and pears (£315/ha, 5p/kg) 5% for the years 2001-2003. A 15% rate would have been regarded as very profitable. At a gross margin level the organic crops were higher than conventional equivalents. With average current prices and costs a breakeven point can be achieved at 7t/ha for apples and 5t/ha for pears. However, the averages fail to show the large range of results that occurred, and that during the survey period nine apple and pear crops (a crop includes all varieties on an individual farm), which represented 43% of the crops grown, made a loss. As costs were fairly similar, the variation in net margin was directly related to the variability in yields. Some farms did notably better than others and this is in part due to their more favourable sites for fruit growing e.g. better soils. It is of some concern that profitability is currently highly dependent on high prices for organic fruit (typically double that of conventional fruit), which may fall as UK supplies increase. A 20% reduction in prices for apples would lead to a halving of net margin and a 45% reduction would lead to all farms making a loss. Although demand for organic dessert fruit continues to grow, the rate of conversion of UK organic dessert top fruit growers to production is still relatively slow. The main constraints continue to be: the high costs of conversion to organic production, estimated to be £6,800/ha for the conversion of an existing orchard over a three-year period, with the cost of establishing a new orchard being greater than £10,000/ha; and the low level and inconsistency of yields and thus profitable returns. To ensure continued investment in new plantings and to allow for management income and profits, average yields need to be increased. It is thought that even with the increased rate of Organic Farming Scheme Payment, of £1860/ha over five years introduced in 2002, will not provide sufficient economic incentive for farmers to convert more land. The crux is that growers are still hampered by low and variable yields due to lack of suitable varieties and the inability to control pests and diseases, which have a major impact on the economics of production. A DEFRA Horticultural LINK project ‘Varieties and Pest and Disease Management for Organic Apple Production, has been addressing some of these issues, although much still remains to be done. The number of growers converting and investment by existing growers in new orchards with more appropriate varieties remains limited. If UK produced organic top fruit, currently meeting 10% of the market, is to rise to comparable levels of self-sufficiency in the conventional sector (21%), then an additional 1,000 hectares ( at current yields) would need to be converted. Since it is the Organic Action Plan objective to see more UK grown organic top fruit, then government and business support for this fledgling sector should continue, and be co-ordinated. It is recommended that support can be provided through further funding for research (e.g. varieties, nutrition, pests and diseases, weeds, market, economics), development and dissemination of existing research

Spending Out - Making It Happen

While it may be of interest to a wider audience, this companion guide is focused on the practicalities of spending out and targeted at those foundations that have decided this is the path for them. By sharing the practical experience of those who are well into the process or have already completed it, we hope to make it easier for others wishing to follow in their footsteps

Heroin withdrawal as a possible cause of acute concomitant esotropia in adults

Aim: To report the possible effects of heroin withdrawal on binocular vision. Methods: To present a case series of patients in whom esotropia developed on cessation of heroin use. Results: In each case the esotropia was concomitant and prismatic correction restored binocular single vision. Intermittent spontaneous control occurred in one patient, the deviation resolved in one and one patient was lost to follow-up. Conclusions: Heroin withdrawal should be considered as a cause of acute concomitant esotropia. However, accurate history of other medication is needed to ensure that this is not the cause of decompensation

Class A drug abuse: an ophthalmologist's problem?

[First Paragraph] The 2002/3 British Crime Survey reported that 3% of all 16 to 59 year olds (equating to around one million people) had used a class A drug in the last year. Use of a class A drug in the 16-24 year old age group (8%) has remained similar since 1996. Use of cocaine and crack cocaine are on the increase. For the first time since 1996 the use of ecstasy has decreased. Poly drug use is not uncommon. During the year 2000/1, 118,500 patients were in treatment with drug misuse agencies and general practitioners. Ocular sequelae from illicit drug use are varied, affecting visual acuity, visual perception, ocular posture or motility, the globe itself or its adnexa. Large studies are not available to allow us to quantify the problem, and many of the reports are of single cases or small case series. However, an awareness of possible problems which may arise from the use of class A drugs may alert the clinician to this as the aetiology of a condition presenting to them