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Notes: Model amphiphiles consisting of lines of Lennard-Jones (LJ) centers are investigated to determine the effect of pressure and molecular geometry on ground-state tilting behavior. Both the amphiphile length and the intramolecular distance between LJ centers is varied. The results give guidelines for understanding and controlling tilting behavior in monolayer films. © 1996 American Institute of Physics.

Notes: A cross-section potential which models the interaction of two planar objects of prescribed shape is developed and used to model the interactions of amphiphiles in vertical phases of Langmuir monolayers. The results of Monte Carlo simulations of an isobaric–isothermal ensemble show qualitative agreement with experiment. The model system undergoes a continuous, bound-to-free rotator transition between phases of the same symmetries as the solid (S) and super liquid (LS) phases exhibited by fatty acid films.

Notes: Proximate analyses and determinations of mean lipid unsaturation have been performed on monthly samples of Scomber scombrus (L) caught off the Cornish coast throughout a period of one year (December 1968-November 1969). Maximum and minimum total-lipid levels were recorded in December and June respectively. The highest mean lipid unsaturation levels were recorded in November and the lowest in May. An inverse linear relationship between lipid and water content with protein level remaining substantially constant was observed. Biometric data were collected on samples of June and December fish and detailed lipid analysis performed on the flesh, liver and gonad. Prominent features of the data are discussed and some comment made on the nature and functions of lipids in fish.

Notes: Summary. Samples of the fish species Argentina silus (Ascanius) have been studied for utilization as a food fish and also for the production of fish meal. the flesh was found very acceptable by taste panels, but because of its unsaturated oil content, rancidity would occur during long-term storage unless precautions were taken to reduce this spoilage.The lipid content and composition of this fish together with the amino acid composition has been measured. the results indicate that fish meal produced from it would be nutritious and have a relatively high oil content, if the fish was not processed as a fatty fish.

Notes: Objectives  To investigate cardiovascular risk factors and changes in risk factor levels in relation to menopausal stage, hysterectomy status and hormone replacement therapy use in a cohort of women aged 53 years with prospective data on smoking, lifetime socio-economic circumstances, and blood pressure and obesity at age 43 years.Design  A prospective study.Setting  England, Scotland and Wales.Population  A cohort of women from the Medical Research Council Survey of Health and Development.Methods  A total of 1303 women, aged 53 years, from a UK birth cohort study with measures of cardiovascular risk factors were classified by five menopausal status groups (premenopause, perimenopause, postmenopause, hysterectomy and hormone replacement therapy user). Body mass index, glycosolated haemoglobin, blood pressure, high density lipoprotein, low density lipoprotein and total cholesterol measurements were taken, and analysed within the groups taking confounding variables into account. Changes in body mass index and blood pressure measurement in the same women obtained when 43 years of age were also compared.Main outcome measures  Body mass index, glycosolated haemoglobin, blood pressure, high density lipoprotein, low density lipoprotein and total cholesterol.Results  At 53 years, body mass index, waist circumference, total and low density lipoprotein cholesterol, and glycosolated haemoglobin (HbA1c) varied by menopausal status group, but blood pressure did not. Levels of total cholesterol and HbA1c increased across the natural menopause transition, before and after adjustment for body mass index, smoking and lifetime socio-economic circumstances. After adjustment for confounders, levels of risk factors for hysterectomised women were similar to those of naturally postmenopausal women. Women on hormone replacement therapy had lower levels of total and low density lipoprotein cholesterol, HbA1c, and were less obese than postmenopausal women. The lower obesity levels were partly due to these women already being less obese at age 43 years.Conclusions  This study showed that naturally postmenopausal or hysterectomised women had higher levels of metabolic risk factors compared with premenopausal or perimenopausal women of the same age. The long term stability of these differences and their translation into variations in incidence of cardiovascular disease remain to be seen. The lower levels of metabolic risk factors for women on hormone replacement therapy may protect against future cardiovascular disease or may be overwhelmed by other adverse, and as yet unknown, effects of hormone replacement therapy.

Notes: Phosphorus (P) is an essential component of fish diets. Its deficiency affects not only hard tissues, where it is responsible for rickets, leading to skeletal malformation, but also influences various aspects of intermediary metabolism, and thus growth and feed conversion. Therefore, optimizing the dietary inclusion level is critical at all times. As the aquaculture industry has expanded, so the effects of P in farm effluents, derived from metabolic and uneaten food sources, have also become recognized. Diets are increasingly formulated on a basis that will not only provide adequate P for fish needs, but also endeavour to ensure minimal acceptable P levels in effluents at the same time. Many variables influence P requirements and P availability in fish diets, so it is inadvisable to feed diets formulated to an assumed minimum dietary requirement level, irrespective of the advantages that such a formulation may provide to environmental impact.

Notes: Investigation of cranial and spinal deformities in Atlantic salmon smolts from Chile immediately after sea transfer, over two successive crops, demonstrated ankylosis of the mandibular articulation, spinal foreshortening, fracture of vertebrae and rarefaction of osseous and cartilaginous tissues including the operculum. As a result the mouth was permanently agape and opercula could be folded back on themselves. All affected fish had been transferred to sea water at 20 °C plus and fed on particular commercial diets. Fish in cooler areas, or on diets high in vitamin C and phosphorus in the high temperature zone, were clinically normal. The condition has not recurred following dietary adjustment.