Estimates of life history parameters in a high latitude, arid-country vervet monkey population

We present data on life history parameters from a long-term study of vervet monkeys in the Eastern Cape, South Africa. Estimates are presented of age at first conception for females and age at natal dispersal for males, along with the probability of survival to adulthood for infants born during the study, female reproductive life-span, reproductive output (including lifetime reproductive success for a subset of females), and inter-birth interval (IBI) duration. We also assess the effect of maternal age and infant survival on length of IBI. We then go on to compare life history parameters for our population with those from two East African populations in Kenya (Amboseli and Laikipia). We find there is broad consensus across the three populations, although mean infant survival was considerably lower for the two East African sites. Such comparisons must be made cautiously, however, as local ecology across the duration of the studies obviously has an impact on the estimates obtained. With this caveat in place, we consider that the concordance between values is sufficient to enable the values reported here to be used in comparative studies of primate life history, although data from habitats with higher rainfall and lower levels of seasonality are needed, and the results presented here should not be seen as canonical.

Absolute calibration of Fujifilm BAS-TR image plate response to laser driven protons up to 40 MeV

Image plates (IPs) are a popular detector in the field of laser driven ion acceleration, owing to their high dynamic range and reusability. An absolute calibration of these detectors to laser-driven protons in the routinely produced tens of MeV energy range is, therefore, essential. In this paper, the response of Fujifilm BAS-TR IPs to 1-40 MeV protons is calibrated by employing the detectors in high resolution Thomson parabola spectrometers in conjunction with a CR-39 nuclear track detector to determine absolute proton numbers. While CR-39 was placed in front of the image plate for lower energy protons, it was placed behind the image plate for energies above 10 MeV using suitable metal filters sandwiched between the image plate and CR-39 to select specific energies. The measured response agrees well with previously reported calibrations as well as standard models of IP response, providing, for the first time, an absolute calibration over a large range of proton energies of relevance to current experiments.

Calibration of BAS-TR image plate response to GeV gold ions

The response of the BAS-TR image plate (IP) was absolutely calibrated using a CR-39 track detector for high linear energy transfer Au ions up to ∼1.6 GeV (8.2 MeV/nucleon), accelerated by high-power lasers. The calibration was carried out by employing a high-resolution Thomson parabola spectrometer, which allowed resolving Au ions with closely spaced ionization states up to 58⁺. A response function was obtained by fitting the photo-stimulated luminescence per Au ion for different ion energies, which is broadly in agreement with that expected from ion stopping in the active layer of the IP. This calibration would allow quantifying the ion energy spectra for high energy Au ions, which is important for further investigation of the laser-based acceleration of heavy ion beams.

Influence of spatial-intensity contrast in ultraintense laser-plasma interactions

Increasing the intensity to which high power laser pulses are focused has opened up new research possibilities, including promising new approaches to particle acceleration and phenomena such as high field quantum electrodynamics. Whilst the intensity achievable with a laser pulse of a given power can be increased via tighter focusing, the focal spot profile also plays an important role in the interaction physics. Here we show that the spatial-intensity distribution, and specifically the ratio of the intensity in the peak of the laser focal spot to the halo surrounding it, is important in the interaction of ultraintense laser pulses with solid targets. By comparing proton acceleration measurements from foil targets irradiated with by a near-diffraction-limited wavelength scale focal spot and larger F-number focusing, we find that this spatial-intensity contrast parameter strongly influences laser energy coupling to fast electrons. We find that for multi-petawatt pulses, spatial-intensity contrast is potentially as important as temporal-intensity contrast.

Socioeconomic gradient in morbidity and mortality in people with diabetes: cohort study findings from the Whitehall Study and the WHO Multinational Study of Vascular Disease in Diabetes

OBJECTIVE

To assess whether the inverse socioeconomic mortality gradient observed in the general population persists in diabetic people.

DESIGN

The Whitehall cohort study and the London cohort of the WHO multinational study of vascular disease in diabetes.

SETTING

London.

SUBJECTS

17,264 male civil servants (17,046 without diabetes, 218 with diabetes) aged 40-64 examined in 1967-9, and 300 people with diabetes aged 35-55 from London clinics examined in 1975-7. Both cohorts were followed up until January 1995.

MAIN OUTCOME MEASURES

Mortality from all causes, cardiovascular disease, and ischaemic heart disease.

RESULTS

In both cohorts people in the lower social groups were older, had higher blood pressure, and were more likely to smoke. In the Whitehall study, the prevalence of heart disease was higher in the lowest social group compared with the highest group, by 6% among non-diabetic people (P = 0.0001) and by 14% among diabetic subjects (P = 0.02). In the WHO study proteinuria was more common in the lowest social group compared with the highest (27% v 15%, P = 0.01), as was retinopathy (54% v 48%, P = 0.5). There was a clear socioeconomic gradient in all cause mortality in both cohorts, with death rates being about twice as high in the lowest compared with the highest social groups. In the Whitehall study this gradient was similar in both diabetic and non-diabetic subjects, and it persisted for mortality from cardiovascular disease and from ischaemic heart disease. About half of the increased risk of death in the lowest social group was accounted for by blood pressure and smoking.

CONCLUSIONS

We confirm the existence of an inverse socioeconomic mortality gradient in diabetic people and suggest that this is largely due to conventional cardiovascular risk factors.

"Movement" in work status after pain facility treatment

STUDY DESIGN

This was a randomized prospective follow-up study of pain facility treatment of chronic pain patients with low back pain, with return to work and work capacity as the outcome measures.

OBJECTIVES

To determine if after pain facility treatment chronic pain patients "move" in and out of work and in their work capacity; to determine the patterns of "movement;" and to determine the post-pain facility treatment follow-up sampling time points that would maximize the number of chronic pain patients correctly classified according to their final work and work capacity status.

SUMMARY OF BACKGROUND DATA

Past research and empiric observation have indicated that chronic pain patients may "move" after pain facility treatment in and out of work and in their job work capacity. Such "movement" can affect the results of outcome studies.

METHODS

Two hundred thirty-six consecutive chronic pain patients who fit study selection criteria were followed up at 1, 3, 6, 12, 18, 24, and 30 months after pain facility treatment for determination of work and work capacity status and separated according to the pattern of movement. Stepwise discriminant analysis was used to answer the study objectives. "Movement" in and out of work for these chronic pain patients also was compared with the US general population.

RESULTS

Chronic pain patients demonstrated eight work and four work capacity movement patterns. The 24- and 1-month time points predicted final work status correctly for 97.0% and 77.0% of the chronic pain patients, respectively, whereas the most significant predictor for correct work capacity status was the 24-month point. The annual percentage change in employment status for these chronic pain patients was more than in the US general population.

CONCLUSIONS

Because chronic pain patients "move" in and out of employment and for work capacity status after pain facility treatment, future outcome studies using these measures will have to consider carefully the impact of "movement" on their results.

Success rates following intracytoplasmic sperm injection are improved by using ZIFT vs IVF for embryo transfer

PURPOSE

The purpose of this study was to analyze whether the mode of embryo transfer (ZIFT vs IVF) affected the outcome in intracytoplasmic sperm injection (ICSI) cycles.

METHODS AND RESULTS

Eighty-two ICSI cycles (42 ZIFT and 40 IVF) were analyzed. Several variables, including patient age and weight, numbers of mature eggs collected, injected, and fertilized, fertilization rate, number of fertilized eggs obtained per cycle, numbers of zygotes/embryos transferred, clinical pregnancy rate, and implantation rate, were compared. Mean patient age and weight were identical. The mean number of mature eggs collected and injected and fertilization rate were significantly higher in the ZIFT group, however, the mean numbers of zygotes/embryos transferred were identical. The clinical pregnancy and implantation rates in ZIFT cycles (52.3 and 23.2% respectively) were significantly higher than in IVF cycles (17.5 and 9.7%).

CONCLUSIONS

These data suggest that ZIFT is the more appropriate method for transfer of ICSI-derived embryos.

Differences in mortality and morbidity in African Caribbean and European people with non-insulin dependent diabetes mellitus: results of 20 year follow up of a London cohort of a multinational study

OBJECTIVE

To examine differences in morbidity and mortality due to non-insulin dependent diabetes in African Caribbeans and Europeans.

DESIGN

Cohort study of patients with non-insulin dependent diabetes drawn from diabetes clinics in London. Baseline investigations were performed in 1975-7; follow up continued until 1995.

PATIENTS

150 Europeans and 77 African Caribbeans with non-insulin dependent diabetes.

MAIN OUTCOME MEASURES

All cause and cardiovascular mortality; prevalence of microvascular and macrovascular complications.

RESULTS

Duration of diabetes was shorter in African Caribbeans, particularly women. African Caribbeans were more likely than the Europeans to have been given a diagnosis after the onset of symptoms and less likely to be taking insulin. Mean cholesterol concentration was lower in African Caribbeans, but blood pressure and body mass index were not different in the two ethnic groups. Prevalence of microvascular and macrovascular complications was insignificantly lower in African Caribbens than in Europeans. 59 Europeans and 16 African Caribbeans had died by the end of follow up. The risk ratio for all cause mortality was 0.41 (95% confidence interval 0.23 to 0.73) (P = 0.002) for African Caribbeans v Europeans. This was attenuated to 0.59 (0.32 to 1.10) (P = 0.1) after adjustment for sex, smoking, proteinuria, and body mass index. Further adjustment for systolic blood pressure, cholesterol concentration, age, duration of diabetes, and treatment made little difference to the risk ratio. Unadjusted risk ratio for cardiovascular and ischaemic heart disease were 0.33 (0.15 to 0.70) (P = 0.004) and 0.37 (0.16 to 0.85) (P = 0.02) respectively.

CONCLUSIONS

African Caribbeans with non-insulin dependent diabetes maintain a low risk of heart disease. Management priorities for diabetes developed in one ethnic group may not necessarily be applicable to other groups.

Characterization of nonradioactive assays for cobalamin-dependent and cobalamin-independent methionine synthase enzymes

Methionine synthase enzymes catalyze methyl group transfer from 5-methyltetrahydrofolate to homocysteine to give methionine and tetrahydrofolate. Assays for this enzyme activity usually monitor transfer of a 14C-methyl group from the N5-position of methyltetrahydrofolate to homocysteine to produce 14C-methionine that must be purified by anion-exchange chromatography. Alternatively, tetrahydrofolate may be derivatized with a formylating agent under acidic conditions to produce methenyltetrahydrofolate. We report optimization of this reaction for assay of cobalamin-dependent methionine synthase to give an economical method for determining enzyme activity that does not require the use of radioactive compounds. By heating for 10 min in 1 N hydrochloric acid containing 12% formic acid, the enzymatic product tetrahydrofolate is converted into methenyltetrahydrofolate, which absorbs light at 350 nm, while residual substrate 5-methyltetrahydrofolate does not contribute to the absorbance at 350 nm. The assay allows the derivatized product to be characterized in situ with a minimal increase in volume upon acidification. The results of the spectrophotometric assay given here have been compared with the radioactive assay to confirm the validity of the derivatization under the assay conditions. We also report the extension of this assay method for use in activity measurements of cobalamin-independent methionine synthase.

Validation of a liquid chromatography post-column derivatization assay for the determination of cisplatin in plasma

Method validation results are described for a cisplatin LC post-column derivatization assay. Cisplatin plasma samples were treated with acetonitrile and a citrate buffer solution to enhance cisplatin stability. Processed samples were analysed on a chemically generated anion exchange column using a customized post-column derivatization platform and refrigerated autosampler. The UV response was monitored at 290 nm. The retention time of cisplatin was 9 min. The assay was linear from 0.06 to 30.0 micrograms ml-1 (r > 0.998) with inter-run precisions (RSD) of 8.2% (n = 8), 5.9% (n = 8) and 4.0% (n = 8) for low (0.18 microgram ml-1), medium (1.5 microgram ml-1) and high (24.0 micrograms ml-1) quality control samples, respectively. The validated assay was used to monitor cisplatin levels in cisplatin drug interaction studies.

Genochondromatosis II

We report a new disorder which we have called genochondromatosis II. The disorder is similar in mode of inheritance and long bone changes to that named genochondromatosis but shows some distinctive features, namely involvement of short tubular bones and normal clavicles. The disorder has a benign clinical course and may be discovered incidentally. Accurate diagnosis is important for proper genetic counselling.

Pelvimetry--a squatter's view

Patients were X-rayed in supine and squatting positions in order to measure any increase in pelvic outlet diameters. An increase of less than 2% was found. Previous estimates of 20-30% increases in pelvic outlet area were not duplicated.

The management of open and complex fractures of the tibia

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Epidemiologic methods in diabetic macrovascular disease

This paper covers the important factors in making valid comparisons in epidemiologic studies, including case definition, validity and repeatability of measurements, and quality control

Diabetes and the heart: coronary heart disease

1. Diabetics have a greater risk of experiencing and of dying from a CHD event than age matched non-diabetics. 2. The excess risk is particularly notable in insulin dependent female diabetics who seem to lose the usual 'protection' accorded to women. 3. The cause or causes of the excess risk are not known. There are a variety of 'risk factors' observed in diabetics which, in sum, may contribute. 4. At least in insulin-dependent diabetics some cardiac morbidity and mortality may also be due, not to coronary heart disease, but to a cardiomyopathy secondary to intramural obstructive vascular disease and/or disordered myocardial metabolism. 5. No therapy has yet been convincingly proved to reduce (or to increase) the risk of cardiac morbidity or mortality. Nevertheless, in treating diabetics there is an a priori case for using diets designed to lower plasma lipid levels as well as the blood sugar, for early treatment of hypertension and for discouraging cigarette smoking.

Facilitation of group desensitization of test anxiety

To enhance the effects of group desensitization in the treatment of test anxiety, a modified desensitization procedure was used, calling for pairing a stimulus (tone) with relaxation training, then presenting the stimulus while Ss completed the test-anxiety hierarchy. 60 college freshmen with high test anxiety were divided into 4 groups of 15 Ss each. One group received the modified group-desensitization procedure while a second group received conventional group desensitization. Two control conditions were included: presentation of a tone while completing the test-anxiety hierarchy, and an attention-placebo condition. The modified desensitization procedure was more effective than conventional desensitization and the control conditions.