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Introduction Creation of gastrointestinal stomas is a common colorectal procedure associated with early or late complications, some of which demand advanced technical skills and expertise for optimal management. Case History A 63-year-old male underwent a defunctioning loop colostomy for locally advanced rectal cancer with liver metastasis. Three months later, he had developed a skinfold over his stoma that resulted in a horizontal skin crease traversing through the stoma, causing the stoma to ‘sink’ leading to obliteration of the stomal opening. This scenario led to ineffective attachment of a stoma appliance, resulting in painful peristomal ulcers. After excision of the anterior abdominal wall, assessment of colostomy opening was carried out, followed by closure of the subcutaneous tissues and drain fixation. An elevated colostomy with an adequate functional opening was seen after wound closure. The patient made an uneventful recovery and was discharged home. After 3 weeks, he had a fully opened, normally functioning colostomy and peristomal ulcers were almost healed. Conclusions This case highlights the challenges of stoma management, its related risks, avoidance of delay in chemotherapy, a patient wish for early return to work, and the novel approach we adopted to deal with these issues.

Annoyance due to environmental odour exposure is in many jurisdictions evaluated by a yes/no decision. Such a binary decision has been typically achieved via odour impact criteria (OIC) and, when applicable, the resultant separation distances between emission sources and residential areas. If the receptors lie inside the required separation distance, odour exposure is characterised with the potential of causing excessive annoyance. The state-of-the-art methodology to determine separation distances is based on two general steps: (i) calculation of the odour exposure (time series of ambient odour concentrations) using dispersion models and (ii) determination of separation distances through the evaluation of this odour exposure by OIC. Regarding meteorological input data, dispersion models need standard meteorological observations and/or atmospheric stability typically on an hourly basis, which requires expertise in this field. In the planning phase, and as a screening tool, an educated guess of the necessary separation distances to avoid annoyance is in some cases sufficient. Therefore, empirical equations (EQs) are in use to substitute the more time-consuming and costly application of dispersion models. Because the separation distance shape often resembles the wind distribution of a site, wind data should be included in such approaches. Otherwise, the resultant separation distance shape is simply given by a circle around the emission source. Here, an outline of selected empirical equations is given, and it is shown that only a few of them properly reflect the meteorological situation of a site. Furthermore, for three case studies, separation distances as calculated from empirical equations were compared against those from Gaussian plume and Lagrangian particle dispersion models. Overall, our results suggest that some empirical equations reach their limitation in the sense that they are not successful in capturing the inherent complexity of dispersion models. However, empirical equations, developed for Germany and Austria, have the potential to deliver reasonable results, especially if used within the conditions for which they were designed. The main advantage of empirical equations lies in the simplification of the meteorological input data and their use in a fast and straightforward approach.

Many jurisdictions compare model predicted odour concentration statistics against regulatory exposure limits or criteria in order to assess the risk of proposed developments resulting in nuisance odour impacts. However dose response studies designed to calibrate such criteria have returned widely divergent findings, particularly regarding the degree of influence that the frequency and intensity of odour impact events have on adverse community response (annoyance). In the absence of clear guidance from empirical data, jurisdictions have adopted a wide range of odour impact criteria and harmonisation has proven difficult to progress. This lack of harmonisation constitutes a significant gap in best-practice standards for odour impact assessment methodology and creates a substantial risk of poor assessment outcomes. In this paper a conceptual framework is developed which facilitates close investigation of the relationship between annoyance levels, the frequency and intensity dimensions of nuisance odour and exposure criteria. Within this framework the efficacy of single-percentile odour criteria to limit nuisance odour impacts is examined for several models of annoyance. Significant short-comings in single-percentile criteria are identified in those models in which both the frequency and intensity of impact events are assumed to influence annoyance on time-scales such as a year. The merits and limitations of an alternative multi-percentile criterion framework approach are examined. Models of annoyance developed within the framework suggest an improved concept of odour criteria that may lead to better assessment outcomes, assist with the reconciliation of some seemingly disparate dose response study findings and aid harmonisation of jurisdictional exposure limits.

Exposure to environmental odour can result in annoyance, health effects and depreciation of property values. Therefore, many jurisdictions classify odour as an atmospheric pollutant and regulate emissions and/or impacts from odour generating activities at a national, state or municipal level. In this work, a critical review of odour regulations in selected jurisdictions of 28 countries is presented. Individual approaches were identified as: comparing ambient air odour concentration and individual chemicals statistics against impact criteria (maximum impact standard); using fixed and variable separation distances (separation distance standard); maximum emission rate for mixtures of odorants and individual chemical species (maximum emission standard); number of complaints received or annoyance level determined via community surveys (maximum annoyance standard); and requiring use of best available technologies (BAT) to minimize odour emissions (technology standard). The comparison of model-predicted odour concentration statistics against odour impact criteria (OIC) is identified as one of the most common tools used by regulators to evaluate the risk of odour impacts in planning stage assessments and is also used to inform assessment of odour impacts of existing facilities. Special emphasis is given to summarizing OIC (concentration percentile and threshold) and the manner in which they are applied. The way short term odour peak to model time-step mean (peak-to-mean) effects is also captured. Furthermore, the fundamentals of odorant properties, dimensions of nuisance odour, odour sampling and analysis methods and dispersion modelling guidance are provided. Common elements of mature and effective odour regulation frameworks are identified and an integrated multi-tool strategy is recommended.

Filtration is the final physical barrier preventing the passage of microbial pathogens into public drinking water. Proper pre-treatment via coagulation is essential for maintaining good particle removal during filtration. To improve filter performance at the Elgin Area WTP, artificial neural network (ANN) models were applied to optimize pre-filtration processes in terms of settled water turbidity and alum dosage. ANNs were successfully developed to predict future settled water turbidity based on seasonal raw water variables and chemical dosages, with correlation (R2) values ranging from 0.63 to 0.79. Additionally, inverse-process ANNs were developed to predict the optimal alum dosage required to achieve desired settled water turbidity, with correlation (R2) values ranging from 0.78 to 0.89.

Granular media filtration is an important process in drinking water treatment to ensure the adequate removal of particle-bound pathogens (i.e., Giardia and Cryptosporidium). Filtration performance is typically monitored in terms of filtered water turbidity. However, particle counts may provide further insight into treatment efficiency, as they have a greater sensitivity for detecting small changes in filtration operation. Artificial neural networks (ANN) models were applied to optimize filtration at the Elgin Area water treatment plant (WTP) in terms of postfiltration particle counts. Process models were successfully developed to predict postfiltration particle counts. Two inverse-process models were developed to predict the optimal coagulant dosage required to attain target particle counts. Upon testing each model, a high correlation was observed between the actual and predicted data sets. The ANNs were then integrated into an optimization application to allow for the transfer of real-time data between t...

Background Evidence of significant variations in clinical biochemistry practice in Wales led to the formation of the All Wales Clinical Biochemistry Audit Group (AWCBAG) in 1993, with the aim of auditing laboratory services to ensure that they are optimally used. As part of this process, clinical guidelines are produced and circulated to all clinical biochemistry departments in Wales. The current aim of the AWCBAG is to assess the extent and impact of adoption of these guidelines across Wales. Methods Three surveys were despatched at intervals over a decade to all clinical biochemistry departments in Wales to investigate practice in: (1) urine albumin testing to screen for diabetic nephropathy; (2) biochemical investigation of menopausal status and the monitoring of hormone replacement therapy; (3) screening for Cushing's syndrome. Results The results show that laboratories across Wales are generally following guideline criteria and are adapting their practice in-line with changing recommendations. Conclusion The introduction of AWCBAG guidelines has been widely accepted by clinical biochemistry departments in Wales. These guidelines have led to a more efficient and effective use of laboratory services.

Highlights • Intranasal immunisation with ChAdOx1.85A induces strong T-cell responses. • ChAdOx1.85A boosted with MVA85A significantly improves the protective efficacy of BCG. • MVA85A boost is protective both after mucosal and systemic administration., A replication-deficient chimpanzee adenovirus expressing Ag85A (ChAdOx1.85A) was assessed, both alone and in combination with modified vaccinia Ankara also expressing Ag85A (MVA85A), for its immunogenicity and protective efficacy against a Mycobacterium tuberculosis (M.tb) challenge in mice. Naïve and BCG-primed mice were vaccinated or boosted with ChAdOx1.85A and MVA85A in different combinations. Although intranasally administered ChAdOx1.85A induced strong immune responses in the lungs, it failed to consistently protect against aerosol M.tb challenge. In contrast, ChAdOx1.85A followed by MVA85A administered either mucosally or systemically, induced strong immune responses and was able to improve the protective efficacy of BCG. This vaccination regime has consistently shown superior protection over BCG alone and should be evaluated further.

Investigations of the equine peripheral vascular system have been constrained by the lack of a non-invasive method of examining the arteries and veins of the limbs of the conscious horse. Precise correlations were established between the gross anatomical features of the peripheral vessels and their B-mode sonographic appearance in each thoracic limb of 35 horses. A sonographic imaging protocol was established. Additional Doppler sonographic recordings defined the arterial waveforms and demonstrated that blood flow to the foot could be evaluated in the lateral proper digital artery, distal to the level of the coronary band. Valves (with 2-4 cusps) were identified in the lumina of the medial and lateral palmar common digital veins and those of the medial and lateral palmar proper digital veins. Spontaneous echo contrast, a smoke-like haze of echoic blood, was seen in the lateral and medial palmar common digital veins, the distal deep palmar venous arch and communicating branches, and the palmar proper digital veins, and occasionally seen in the distal deep palmar arterial arch and distal proper palmar digital arteries. The value of duplex sonography (B-mode and Doppler) for anatomical and physiological studies of the peripheral vasculature of the horse was clearly established. Such data could be applied to the investigation of diseases affecting the peripheral circulation.

Quasi-three-dimensional volume imaging provides an inexpensive means of evaluating the usefulness of three-dimensional imaging. The technique works most efficiently with water-skin interfaces and therefore we investigated its application in obstetrical ultrasonography. Three-dimensional perspectives of the normal and abnormal fetal head and face were spectacular and at times provided more information than the two-dimensional images. The ability of an inexperienced observer to interpret the three-dimensional image more easily may have a role in training sonographers and counseling parents whose fetuses have structural defects. Volume imaging has certain limitations and can only be used as a complementary technique.

A commercial method for N-acetyl-β-glucosaminidase (NAG) is described for use on a discrete analyser. Timed overnight urine was obtained from 20 healthy volunteers and 60 Type I diabetic patients for estimation of NAG (expressed in relation to creatinine) and albumin excretion rate (AER). The upper reference limit for NAG excretion in the control patients was found to be 0·25 U/mmol creatinine but was abnormally raised in 60% of Type I diabetic patients before any increase in AER (greater than 20 μg/min), and in 82% of patients with AER greater than 200 μg/min. A positive correlation was found between NAG excretion and AER in Type I diabetes ( r = 0·61, p < 0·01), but not with glycaemic control as measured by serum fructosamine levels. We conclude that measurement of NAG excretion in diabetes indicates renal tubular dysfunction or damage before any significant change in albumin excretion rate.

Real-time three-dimensional views of the fetus can be obtained with minor modification to conventional scanners. The modification consists of placing a divergent lens in the out-of-scan plane of the transducer to generate a beam fan-beam in the insonated volume. All of the echoes from which insonates a volume rather than a slice of tissue. Scanning is performed using oblique angles of incidence to provide total reflection conditions. Echoes are then received only from anterior surfaces, automatically generating the three-dimensional views. Intriguing portrayal of fetal detail can be obtained with this form of imaging which is likely to expand the clinical utility of sonographic examinations. Copyright © 1994 International Society of Ultrasound in Obstetrics and Gynecology

In transvaginal scanning the tissues intervening between the fetus and transducer are relatively thin. The average thickness in the first trimester is 25 mm and reduces to 15 mm by the third trimester; the minimum thicknesses are 14 and 8 mm, respectively. Two models are proposed for calculating exposure in transvaginal scanning. The models are considered in terms of the overlying tissues and the target tissues. A fixed path, constant attenuation of 0.3 dB/MHz describes the properties of the overlying tissues throughout pregnancy. In the model used in first-trimester scanning, the target tissues of the embryo/fetus are considered to have properties similar to those of soft tissues, and they attenuate the energy at the same rate as the overlying tissues. In the model used in second- and third-trimester scanning, the bony structures of the fetus are the target tissues. These reflect 30% of the incident energy and attenuate all of the transmitted energy at their surface.

The reaction of selenium tetrachloride with the dichlorothiophene diselenolate 3,4-C4Cl2S(SeLi)2 gives triselenole (I) in 38% yield. Purification of I is difficult due to the occurrence of a facile decomposition on attempted dissolution in a variety of solvents.

Several studies have suggested that dietary protein quality may be an important determinant in the natural history of renal disease. We have therefore studied the effects of a predominantly vegetarian diet in eight patients with Type 1 diabetes mellitus and an albumin excretion rate (AER) in excess of 30 micrograms min-1. The AER was measured after an 8-week run-in period on the patient's usual diet, and again after 8 weeks of a predominantly vegetarian diet in which the proportion of vegetable protein was supplemented in order to minimize the reduction in total dietary protein intake. The median fractional albumin clearance fell during the study from an initial value of 188 x 10(-+) (range 58-810 x 10(-4)) at the end of the run-in period to 87 x 10(-4) (23-829 x 10(-4)) at the end of the period on low animal protein diet (difference 79 x 10(-4) (95% Cl 9-149 x 10(-4)), p less than 0.05). The AER then returned to values similar to those obtained at the beginning of the study after a further 8 weeks in those patients returning to their usual diet. No significant changes in blood glucose control or in arterial pressure were observed. A predominantly vegetarian diet may therefore have important beneficial effects on diabetic nephropathy without the need for a heavily restricted total protein intake.

Transvaginal images, under matched conditions, are in general superior in quality to transabdominal sonograms. The difference is, however, not dramatic and instances frequently occur when the same quality and even inferior images are obtained on transvaginal examinations. The dominant factor is the amount of overlying tissues. For the same thickness, subcutaneous tissues have greater degrading characteristics. Subcutaneous tissues also mar the quality of images by giving rise to strong multiple reflection artifacts. The major factors for image degradation are associated with a moderate increase in the width of the ultrasonic beam and a large increase in the side lobes. The dramatic superiority of transvaginal imaging described in previous comparison studies is due principally to the use of higher frequencies, more strongly focused beams and closer positioning of tissues to the transducer. Copyright © 1991 International Society of Ultrasound in Obstetrics and Gynecology

In ultrasonic volume imaging, the effect of rotating the transducer about the central axis of the imaging plane is equivalent to rotation of the insonified volume. The authors present schematics to depict the action and sonograms in two cases (a hand immersed in water and a 36-week fetus) to demonstrate this phenomenon. This maneuver can be used to "rotate" the imaged structures, which enhances their three-dimensional representation.

In six normal adult horses, pulsed-wave Doppler sonographic inspections were made of the left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb. Using a two-period, crossover design with repeated measures, each LPPDA was inspected on four occasions throughout the day over a 7 hour period and, on each occasion, with the limb weight bearing and non-weight bearing. In comparison with the observations made during weight bearing, there were significant increases (P

To assess prospectively the effects of low dose oestradiol on arterial endothelial and smooth muscle function in healthy men. Oestrogen use is associated with reduced cardiovascular disease in oestrogen-deficient women, however, the vascular effects of low-dose oestradiol in healthy men have not been investigated previously.Twenty-three men (aged 32 +/- 8 years) were randomized to receive depot implants of testosterone (T) alone (group 1, n = 10), or T with either 10 mg (group 2, n = 7) or 20 mg (group 3, n = 6) of oestradiol (E).Hormone levels, lipids and vascular reactivity were measured before, 1 month and 6 months after hormone implantation. Using high-resolution ultrasound, brachial artery diameter was measured at rest, during reactive hyperaemia (leading to flow-mediated dilatation, FMD, which is endothelium-dependent) and after sublingual nitroglycerin (GTN, an endothelium-independent dilator).Oestradiol produced a dose-dependent increase in plasma oestradiol (at 1 month 96 +/- 7, 149 +/- 6, 192 +/- 23 pmol/l in the 3 groups, respectively, P0.001 by ANOVA for trend). Minor side-effects (gynaecomastia, nipple tenderness) indicated that 20 mg oestradiol was the maximum tolerated dose. There was also a dose-dependent increase in FMD with oestradiol dose: at 1 month, - 0.2, + 0.2 and + 1.8% for groups 1-3, respectively (P = 0.31 by ANOVA for trend); and at 6 months, - 0.8, + 0.4 and + 2.2% (P = 0.02). The rise in oestradiol levels following treatment correlated with the improvement in FMD (P = 0.01). GTN responses were similar in the 3 groups throughout the study.In healthy young men, oestradiol supplementation is associated with enhanced arterial endothelial function, a key marker of vascular health.

Fluorescent labelling methods for detecting microorganisms in water have limited sensitivity partly due to the natural autofluorescence from environmental particles. The aim of this study was to examine the autofluorescence of water samples to determine the optimal excitation source and fluorescent labels for minimising background autofluorescence and therefore enhancing sensitive detection of Cryptosporidium oocysts. Particles concentrated from water were examined using fluorimetry at a wide range of excitation wavelengths to determine their autofluorescent properties. Two major peaks were identified emitting at 390 to 510 nm and at 640 to 700 nm. Flow cytometry was used to define the optical properties of oocysts immunofluorescently labelled with a range of fluorochromes. Concentrated water samples were analysed using flow cytometry and the number of particles with fluorescence and light scatter properties similar to the fluorescently labelled oocysts recorded. Fluorescein isothiocyanate exited at 488 nm was the most suitable label for oocysts in untreated water with less than 70 particles having optical properties similar to labelled oocysts, detected in 10 litre concentrates. The fluorochromes CY3, phycoerythrin (PE), and tetramethylrhodamine B thioisocyanate (TRITC) excited at 542 nm were the most suitable labels for oocysts in drinking water with less than 40 particles having optical properties similar to labelled oocysts, detected in 100 litre concentrates.

Pompholyx is a form of acute dermatitis localised to the palms and soles, presenting as an itchy eruption with vesicles that can amount to bullae if severe. Chronic dermatitis may be hyperkeratotic, and secondary skin changes include uncomfortable desquamation, painful fissuring, and secondary infection. The functional consequences of chronic, severe palmoplantar dermatitis can be debilitating, with difficulty in walking or in using the hands. The mainstays of treatment are topical corticosteroids or preparations containing corticosteroids plus antimicrobials, with or without an occlusive dressing to aid penetration, but the response to treatment can be unpredictable and only partially successful. Second line treatments such as systemic corticosteroids, psoralen-UVA photochemotherapy, or ciclosporin have occasionally to be considered. Azathioprine is a mercaptopurine immunosuppressive drug used widely across many medical specialties, probably most often as a steroid sparing agent. It is not often used as the sole treatment for pompholyx, but excellent responses have been described.1 The main problem with azathioprine is acute myelotoxicity manifesting as pancytopenia. Advances in the understanding of azathioprine metabolism have been made over recent years, and it is now known that the risk of acute myelotoxicity can be obviated by measuring, before treatment, the enzyme responsible for inactivating azathioprine (thiopurine methyltransferase (TPMT)). Publications on the measurement of erythrocyte TPMT activity first appeared as long ago as 1978 and on mercaptopurine pharmacogenetics in 1980.2 3 Others have since drawn attention to the importance of this in clinical practice,4–8 and prior measurement of TPMT activity is now recognised as best practice in several authoritative guidelines in dermatology. …

Fluorescence-activated cell sorting was used to isolate five spores of the soil amoeba Dictyostelium discoideum that carried new glycosylation mutations, which were produced by restriction enzyme-mediated integration (REMI)-induced gene disruption and which occurred at frequencies of around 10(-5). These mutations were identified by the loss of an O-glycosylation epitope found on surface proteins of wild type D. discoideum spores that is recognised by the monoclonal antibody MUD62. A secondary antibody conjugated to the fluorochrome fluorescein isothiocyanate identified MUD62 bound to spores. Spores lacking this epitope did not fluoresce, allowing this population to be separated. Samples were found to contain around 0.1% of viable spores that were wild type but lacked the MUD62 epitope at the time of sorting. To remove these spores from the unlabelled population, samples were labelled with monoclonal antibody MUD50, which recognises surface proteins on immature spores and proteins exposed from an inner coat layer. Double labelling with MUD50 and MUD62 reduced the unlabelled viable population to less than 0.002%, allowing the glycosylation-defective spores to be isolated. This is the first use of a selective approach to isolate nonmorphological REMI-induced mutants in D. discoideum. This study also characterises the surface properties of spore types found in mature fruiting bodies of D. discoideum.

To correct distortion in ultrasonic images caused by refraction at fat-muscle interfaces in the subcutaneous tissues.A forward-propagation technique was developed that used a priori information of the acoustic properties of the layers. The thickness and shape of these tissues were measured, and a correction was applied for the different velocities in the tissues. A synthetic-aperture scanning technique was used to allow correction to be applied with data obtained in a single scan. The technique was tested in three tissue phantoms with overlying aberrating layers (six images) and in eight volunteer subjects (37 images). The superior mesenteric artery and the aorta were used as test sites within the body, because it is relatively easy to obtain double images of these vessels owing to refraction of the scanning beam by the rectus muscles.Distortions such as double-image artifacts and texture disruption were corrected with use of this technique. Six of the six phantom images and 22 of the 37 images in humans were corrected with use of this technique.The forward-propagation technique compensates for refraction at subcutaneous fat-muscle interfaces.

Real-time three-dimensional views of the fetus can be obtained with minor modification to conventional scanners. The modification consists of placing a divergent lens in the out-of-scan plane of the transducer to generate a beam fan-beam in the insonated volume. All of the echoes from which insonates a volume rather than a slice of tissue. Scanning is performed using oblique angles of incidence to provide total reflection conditions. Echoes are then received only from anterior surfaces, automatically generating the three-dimensional views. Intriguing portrayal of fetal detail can be obtained with this form of imaging which is likely to expand the clinical utility of sonographic examinations.

Aims (1) To identify the yield of aetiological medical investigations in neonates confirmed to have permanent unilateral hearing loss (UHL) following detection by the newborn hearing screening, (2) To identify the association between aetiological medical investigations, risk factors for deafness, audiological profile and stability of hearing loss. Method This was a 14-year retrospective case-note study of 59 newborns with permanent UHL confirmed by Auditory Brainstem Response test performed at a tertiary Paediatric Audiovestibular Medicine Department following referral by newborn hearing screening. The associations between the aetiological medical investigations, risk factors for deafness and audiological profile were analysed using χ 2 statistics. Results High yields were obtained with MRI of internal auditory meati and with CT of the petrous temporal bones (75% and 80%, respectively). Investigation of congenital Cytomegalovirus infection gave a yield of 22%. Significant associations were found between the presence of physical examination signs and a positive CT finding (p=0.005) and the type of UHL (p=0.004). Degree of UHL had a strong association with a positive MRI result (p Conclusion We recommend prioritising imaging studies (MRI and/or CT) and investigation of congenital Cytomegalovirus infection in newborns confirmed with UHL. The results highlight the importance of a comprehensive physical examination as it will guide the medical investigation protocol, especially imaging studies. Those newborns confirmed with congenital Cytomegalovirus infection will benefit from longitudinal follow-up to detect progression of hearing loss. Future research with a larger sample is required for further recommendations.

Transvaginal images, under matched conditions, are in general superior in quality to transabdominal sonograms. The difference is, however, not dramatic and instances frequently occur when the same quality and even inferior images are obtained on transvaginal examinations. The dominant factor is the amount of overlying tissues. For the same thickness, subcutaneous tissues have greater degrading characteristics. Subcutaneous tissues also mar the quality of images by giving rise to strong multiple reflection artifacts. The major factors for image degradation are associated with a moderate increase in the width of the ultrasonic beam and a large increase in the side lobes. The dramatic superiority of transvaginal imaging described in previous comparison studies is due principally to the use of higher frequencies, more strongly focused beams and closer positioning of tissues to the transducer.

Summary A 30 year old male patient with thyrotoxic crisis presenting as status epilepticus is reported. The aetiology, manifestations and management of this medical emergency are discussed. The importance of prompt, vigorous and comprehensive treatment of thyrotoxic crisis is emphasized. Rapid control of hyperthyroidism as well as other supportive measures are essential if the high fatality rate is to be reduced. Comprehensive management reduces mortality from 90% to 20%.

Summary. The waveforms of vessels supplying the ovaries of women on an in-vitro fertilization (IVF) programme were studied using transvaginal B-mode and Doppler ultrasound. There were 125 scans recorded in 65 women at weekly intervals from 3 days after embryo transfer or 5 days after gamete intrafallopian transfer (GIFT) until confirmation of pregnancy or onset of menses. At each examination the signals obtained from vessels supplying the ovaries were recorded and quantified using a resistance index (RI). Fifteen patients became pregnant of whom one has subsequently miscarried. There was a highly significant difference in the RI values between patients who became pregnant and those who did not; no patient who became pregnant had a RI greater than 0.5. Oestrogen to progesterone ratios were calculated in the subgroup of non-pregnant patients and there was no correlation between these values and the RI values. This new technique enables prediction of IVF treatment failure earlier than has been reported previously and may reflect the inadequacy of the corpus luteum.

The reaction of selenium tetrachloride with the dichlorothiophene diselenolate 3,4-C4Cl2S(SeLi)2 gives triselenole (I) in 38% yield. Purification of I is difficult due to the occurrence of a facile decomposition on attempted dissolution in a variety of solvents.

The overwintering mature larva of the parasite Anastatus disparis Ruschka within the intact gypsy moth, Lymantria (= Porthetria) dispar L., egg chorion is susceptible to freezing and has a mean supercooling point of −28.8±0.14°C. This level of cold hardiness is not increased by exposure to sublethal low temperatures. Over 85% of larvae survived 10 months at 0°C and 4 days at −12° or −18°C, both followed by an additional 2–3 months at 0°C, but over half of the survivors went into prolonged diapause which was not fulfilled by subsequent rearing at room temperature. The parasite is apparently capable of surviving winter conditions over the same geographic area in Canada as the gypsy moth, and the introduction of A. disparts into locations in Canada where gypsy moth is now present is recommended.

Neonatal screening for congenital hypothyroidism was introduced in the City of Birmingham in 1980 by measuring concentrations of both thyroid stimulating hormone and thyroxine in plasma. Over two years 30 108 babies were tested. Thirty one babies were recalled because of thyroid stimulating hormone concentrations greater than 40 mU/l, of whom 12 were treated with replacement thyroxine. Six babies were found to have low thyroxine concentrations because of reduced thyroxine binding globulin and five raised thyroxine values because of increased thyroxine binding globulin. As a result of this study screening was continued with measurement of thyroid stimulating hormone only as the primary test for congenital hypothyroidism, the thyroxine value being measured only when the concentration of thyroid stimulating hormone exceeded 20 mU/l.

Fourteen children with salt losing and five children with non-salt losing congenital adrenal hyperplasia were studied. Venous samples were collected for measurement of plasma renin activity, serum 17 alpha-hydroxyprogesterone, testosterone, sodium, and creatinine. Overnight urinary sodium and creatinine excretions were measured after collection on an outpatient basis. Eight 'salt losers' had a raised plasma renin activity despite mineralocorticoid treatment, as did one 'non-salt loser'. Six of the children in whom clinical and biochemical control was inadequate, including the 'non-salt loser', had an increase in the dose of fludrocortisone. When the investigations were repeated one month later, a fall in plasma renin activity accompanied by a fall in 17 alpha-hydroxyprogesterone in all but one patient were found. The dose of mineralocorticoid may be as critical as the dose of glucocorticoid in the management of congenital adrenal hyperplasia, and regular determination of plasma renin activity should be made, particularly if clinical control is difficult.

Females ofPleolophus basizonus (Gray.) show a very strong avoidance of cocoonedNeodiprion sertifer (Geoff.) prepupae in which there are eggs, larvae or prepupae ofLophyroplectus luteator (Thunb.). When multiparasitism does occurP. basizonus is the successful competitor but adults are much smaller than those from hosts that were not multiparasitized.

There are many different flaps available for head and neck reconstruction. The latissimus dorsi myocutaneous flap has been widely used in this unit on 80 occasions in the past three years, both as a pedicled and as a free microvascular flap following the excision of head and neck malignancy, the commonest pathology being intraoral squamous cell carcinoma.There were nine cases of complete or substantial flap loss requiring a further reconstructive procedure. Few of the patients who underwent total glossectomy suffered from overspill or aspiration and the fistula rate was low.Reference is made to the anatomy and the technique of raising this versatile flap which provides a large volume of tissue and has been particularly useful following total glossesctomy when combined with a hyoid hitch.

The overwintering adult of Ooencyrtus kuwanai (How.) is susceptible to freezing. Male adults from New Jersey have a mean supercooling point of −9.6 ± 0.37°C, significantly higher than those from Maine (−12.3 ± 1.08°). Neither group had its cold hardiness increased by exposure to sublethal temperatures. Female adults from New Jersey had a mean supercooling point of −10.8 ± 0.69° when tested after rearing at 22°C, again significantly higher than that of similarly treated female adults from Maine (−15.4 ± 0.90°). Exposure of New Jersey females to sublethal temperatures decreased their supercooling point significantly, to −14.5 ± 1.59°. Maine female adults were not tested after that treatment. No adults survived continuous exposure to 0°C for 30 days. Hence this parasite is apparently incapable of surviving in the current range of the gypsy moth in Canada.

Adult femaleLophyroplectus luteator (Thunb.) oviposit in all feeding stages ofNeodiprion sertifer (Geoff.), although they prefer the smallest of any larvae present at a given time. Females tend to distribute eggs contagiously both within and between host feeding colonies. Eclosion of eggs does not occur until after the host has spun its cocoon. Larval development then requires approximately 1 month in the laboratory. There is an obligatory eonymphal diapause which requires a minimum of 60–80 days at 2°C to fulfil, and post-diapause development requires 3–4 weeks.

Lophyroplectus luteator (Thunb.), a European ichneumonid parasite previously established on Neodiprion sertifer (Geoff.) in southwestern Ontario, was released near Hepworth, Ontario in 1970, on Manitoulin Island and in Sault Ste. Marie, Ontario in 1972. All three releases resulted in establishment. Data on attack levels and host densities are presented for up to 4 years after release. Dispersal within release areas was rapid. In the first generation after release on Manitoulin Island parasites were obtained up to 900 m from the release site.

The first North American collection of the European pine sawfly, Neodiprion sertifer (Geoff.), was made in Somerset County, New Jersey, in 1925 (Hamilton, 1943). It was first recorded in Canada near Windsor, Ontario, in 1939 (Raizenne, 1957), and by 1946 it had spread as far east as London (Watson, 1946). This serious pest of pines has continued to spread, and is now found throughout most of southwestern Ontario (Fig. 1) (Sippell and MacDonald, 1958). This is the only infestation of this species in Canada.

The upper limit for continuous development ofPleolophus basizonuslies between 25° and 30 °C since all stages develop at the former temperature and larval mortality is complete at the latter temperature. The lower limit lies between 5.5° and 10 °C, since an eonymphal diapause occurs at 5.5 °C. Between these extremes, diapause incidence varies inversely with temperature. The photoperiod experience of the parent has no effect on diapause in the progeny when the latter are reared at 15° and 18 °C, but there is an inverse relation between parental photoperiod experience and progeny diapause incidence at 10 °C. Although larvae and pupae also survive 3 months at 2 °C, most individuals probably overwinter in eonymphal diapause and their diapause requirements are fulfilled in 3 weeks at 2 °C. The incidence and rate of post-diapause development is directly related to temperature.

In Neodiprion sawflies the cocoon stage, which extends from the completion of larval feeding until the appearance of the adult, is of considerable ecological interest. On the basis of voltinism and the seasonal occurrence of the cocoon stage, the genus as a whole may be divided into two distinct groups, which, however, do not correspond to the two major taxonomic categories of Ross (1955). On the one hand are species that overwinter only within the cocoon (e.g. swainei, lecontei, virginianus, excitans, and others); these may or may not have more than one generation per year. On the other hand are species that overwinter primarily in the egg stage (e.g. sertifer, pratti, abietis, taedae, and others); all of these are univoltine and may remain within the cocoon for an extended period in the summer, when conditions are still favourable for further generations. The European pine sawfly, Neodiprion sertifer (Geoff.), is typical in this respect. Despite its wide distribution in Eurasia and North America, and the variety of climates that it encounters, the length of the cocoon stage is so adjusted that adults do not emerge until late summer or early autumn, regardless of when larval feeding and cocoon spinning occurred.

Aptesis biasizona (Grav.) is a common and widely distributed parasite of diprionid sawflies in central, western, and northern Europe, with parasitism varying from three to 90 per cent on different hosts and in different areas. One of these sawflies, Neodiprion sertifer (Geoff.), is very commonly attacked, with parasitism of 30 to 80 per cent in Czechoslovakia, 10 to 52 per cent in Hungary, and 17.5 to 40 per cent in Sweden (Morris et al., 1937).

The possibility of imperfect coincidence between the appropriate stages of Neodiprion sertifer (Geoff.) and two of its important parasites was demonstrated. One of the parasites, the indigenous ichneumonid Exenterus canadensis Prov., which attacks late-stage larvae, has good spatial coincidence; but some members of each generation suffer from imperfect temporal coincidence, or asynchrony, caused by the interaction of temperature influence on parasite development rate and temperature variability between development sites in the litter. The second parasite, Pleolophus basizonus (Grav.), is an introduced, multivoltine ichneumonid cocoon parasite. It may be imperfectly synchronized in its first generation each year and may show imperfect spatial coincidence in all generations through its inability to attack host cocoons beneath approximately 1 in. or more of litter.The intricate relations between parasite and host density, time, attack, and coincidence were investigated using the basic functional response submodel developed by Holling, a submodel that describes changes in oviposition behaviour with time, and a submodel that predicts the number of hosts attacked, given the number of eggs laid and data on the distribution of eggs among hosts. In the two species studied, the effect of asynchrony in one generation cannot be considered without considering the influence of superparasitism. At low host densities, superparasitism largely buffers the effects of decreased synchrony. This buffering effect decreases as host density increases until when each parasite is attacking all the hosts it can, it is almost eliminated. Imperfect spatial coincidence in one generation merely lowers the usable host density. Thus its effect can be seen in the functional response of the parasite to host density. When host–parasite interactions over 25 to 35 host generations were simulated, using initial conditions resembling those ensuing when small numbers of both host and parasite invade a previously unattacked stand, populations became stable after passing through one or more oscillations. Decreasing temporal or spatial coincidence increased host and parasite densities at the peaks of oscillations and increased the ultimate steady density of host and parasite, until coincidence was reduced to nearly half. At this level, the host escaped the regulating ability of both species of parasites.

The oviposition behaviour of Neodiprion sawflies has been the subject of much investigation in recent years. The impetus for this interest seems to lie in the paper by Atwood and Peck (1943), in which it was suggested that the number and spacing of eggs on needles were a useful tool for the identification of memhers of this important group of conifer defoliators. Ghent (1955) has analysed the egg clusters of N. pratti banksianae Roh., and Ghent and Wallace (1958) have investigated the behaviour responsible for the pairing of eggs on adjacent jack pine (Pinus banksiana Lamb. ) needles by N. swainei Midd. More recently, Ghent (1959) has presented a study of the factors determining the spacing of eggs by the European pine sawfly, N. sertifer (Geoff.). Of these, the 1955 and 1959 papers, in addition to making valuable contributions to our understanding of the behaviour of adults, cast doubt on the usefulness of the number and spacing of eggs as identifying characters in these species.

A generalized competition model for predators or parasites was developed from data obtained from a specific parasite–host system. It was structured in three parts. The first simulates the effects of exploitation, where the number of attacks and their distribution among prey or hosts determine how many prey or hosts survive. Since the negative binomial distribution described these distributions consistently, the exploitation submodel was developed from it. The second portion of the competition model concerned interference between searching predators and parasites. Although interference is a universal phenomenon, we were able to show that its effects become important only at predator densities much higher than those that occur in nature. Thus the interference component can be essentially ignored. The third and final component concerned the outcome of competition between parasite progeny within their host. It was developed from Fujii’s competition model which allows for the simulation of both scramble and contest types of competition.These three submodels of competition were combined and coupled with a previously published model of the effects of prey density on attack. In this way the full consequences of different prey and predator densities could be simulated using a model whose constituent parts had been carefully tested for descriptive adequacy. The simulations showed the way individual predator attack, per cent predation, and progeny production were affected by different degrees of contagion in the distribution of attacks, by scramble vs. contest competition, and by the degree to which parasites could avoid hosts already attacked.

Ourbreaks of the jack-pine sawfly, Neodiprion pratti banksianae Rohwer, occur in northern Ontario at irregular intervals. Two independent outbreaks within 50 miles of each other – one on Great Cloche Island (McGugan et al., 1952) which lies in the North Channel of Lake Huron between Manitoulin Island and the mainland, and the other near Nairn Centre, approximately 30 miles west of Sudbury, Ontario – offered an opportunity to study the parasitism of this important defoliator. In 1954, when the study was started, heavy defoliation had been reported for several years in the Great Cloche outbreak, and light defoliation had occurred for one year in the Nairn Centre outbreak. Populations decreased in the Great Cloche area but remained relatively constant at a low level in the Nairn Centre area during 1955 and 1956, when the work was completed.

Lophyroplectus luteator (Thunb.), a European ichneumonid, has been established as a parasite of Neodiprion sertifer (Geoff.) from a release made in 1962, and has dispersed approximately 12 miles (19.3 km) in the 7 years following introduction. A second, smaller release in the same year failed. In a third release, made in 1964, recoveries were made every year until sampling was stopped in 1971, but dispersal has only been approximately 2 miles (3.2 km).