Broom and honeybees in Australia: an alien liaison.

Facilitative interactions between non-indigenous species are gaining recognition as a major driver of invasion success. Cytisus scoparius (L.) Link (Fabaceae), or Scotch broom, is a cosmopolitan invasive shrub that lacks the capacity for vegetative reproduction and is a good model to study facilitative interactions. Its success in pioneer environments is determined by constraints on its reproduction. We determined whether pollinators were required for seed set in C. scoparius at Barrington Tops, NSW, Australia, where the species has infested ca. 14,000 ha across the plateau. Field and laboratory experiments showed that C. scoparius is an obligate outcrossing species at Barrington Tops. Monitoring of plants (10.7 h) showed that the flowers of C. scoparius have to be tripped to effect seed set and the only pollinator to do this was the introduced honeybee, Apis mellifera L. Most floral visits by honeybees result in fruit set (84 %) and because fruits have many ovules (10 - 18 per ovary) a single bee on an average foraging day can effect the production of over 6000 seeds. A review of C. scoparius pollination across four continents revealed major differences in pollen quantity, which may explain differences in the efficiencies of honeybees as pollinators of C. scoparius. The incorporation of pollinator management in an integrated approach for the control of C. scoparius is discussed.

Menstrual disorders and occupational, stress, and racial factors among military personnel.

Few studies have assessed multiple stress factors as a potential risk for menstrual disorders. This study evaluated whether work-related stress or life event stress was associated with alterations in menstrual function of military personnel. The study is unique in that it evaluated the association between race and three job factors--job stress, handling chemical mixtures, and being a military or civilian employee of the US Air Force. A comprehensive questionnaire was administered to 170 healthy, premenopausal employed women to examine the relationship between work-related or life event stress and menstrual disorders. Multiple logistic regression analyses showed no statistically significant association between work-related stress and menstrual disorders, whereas life event stress was significantly associated with dysmenorrhea (odds ratio [OR], 2.20; 95% confidence interval [CI], 1.08 to 4.50) abnormal cycle length (OR, 3.42; CI, 1.12 to 10.50), and hypermenorrhea (OR, 2.99; 95% CI, 1.20 to 7.42). Having one or more menstrual disorders was significantly associated with life events by race interaction (OR, 6.52; 95% CI, 2.45 to 17.36). Non-Caucasians had significantly increased risks of hypermenorrhea (OR, 4.99; 95% CI, 2.07 to 12.05) and abnormal cycle length (OR, 4.12; 95% CI, 1.47 to 11.55). The prevalence of menstrual disorders in this military population was 31.2% for dysmenorrhea, 17.9% for hypermenorrhea, and 12.0% for abnormal cycle length. This study suggests that women in the military report less day-to-day job stress but more atypical life events, including those related to their jobs, and that these life events are associated with adverse menstrual consequences.

Weight change and lung function: implications for workplace surveillance studies.

This study evaluated the relationship between weight change and longitudinal measurement of lung function among 361 men providing at least five pulmonary function tests. The men in this study were participants in a workplace pulmonary surveillance program for subjects with exposure to refractory ceramic fibers (RCFs). Occupational and environmental studies are generally designed to evaluate factors suspected of causing excess decline in lung function. Failure to adequately account for all significant factors may lead to erroneous conclusions regarding change in lung function. This study utilized two different statistical models to evaluate longitudinal changes in a cohort of RCF workers. What was unique to this study was the modeling of longitudinally measured initial weight, weight change, and longitudinal exposure before and during the period of observation. Results showed a strong relationship between weight gain and longitudinal loss in lung function that approximated forced vital capacity declines of 16 mL for every kilogram of weight gain per year in both models. This value is comparable or greater in magnitude and significance to other factors known to be inversely related to lung function, such as age and pack-years smoking to time of initial testing. In conclusion, weight gain was found to have a significant impact on longitudinal change in lung function. Therefore, weight gain becomes a very important variable that requires consideration whenever longitudinal studies of pulmonary function are conducted.

Evaluation of a flexible ruler technique for measuring lumbar lordosis in the clinical assessment of low back pain.

This preliminary study was designed to evaluate a possible objective technique for the clinical measurement of spinal mobility using a flexible ruler. Thirty-one manual workers employed by British Steel Corporation suffering from low back pain were examined using this technique. The results were compared with those obtained from a matching group of workers who did not suffer from low back pain. The technique proved to be simple, accurate and highly reproducible as a clinical tool in the measurement of spinal mobility. A comparison of the observed spinal profile measurements demonstrated a significant difference in lumbar lordosis between the two groups. This suggested that the previously under-rated clinical sign of loss of lumbar lordosis might provide a useful measurement in evaluation of low back pain. Other findings were that low back pain was associated with decreases in extension measurements. There was also a correlation between height and the low back pain group.

Serum alkaline phosphodiesterase I in experimental biliary obstruction in the rat.

Alkaline phosphodiesterase I was present in rat liver at approx. 100-fold greater activity than alkaline phosphatase, and in rat bile at approx. 25-fold greater activity. Rat serum alkaline phosphodiesterase I was increased 6-fold whilst serum alkaline phosphatase was increased only 2-fold 96 h after bile duct ligation. In contrast to alkaline phosphatase, hepatic alkaline phosphodiesterase I was not affected by bile duct ligation, suggesting its raised serum activity was due to bile regurgitation rather than overspill of the enzyme from liver into blood. Gel filtration showed that 8 and 96 h after bile duct ligation the serum contained a high molecular weight form of alkaline phosphodiesterase I. It is suggested that alkaline phosphodiesterase I offers a potentially useful indicator of biliary obstruction in the rat.