Biology and phenology of the eriophyid mite, Floracarus perrepae, on its native host in Australia, Old World climbing fern, Lygodium microphyllum

The biology and phenology of the eriophyid mite, Floracarus perrepae Knihinicki and Boczek,a potential biological control agent of Lygodium microphyllum (Cav.) R. Br., was studied in its native range - Queensland, Australia. F. perrepae forms leaf roll galls oil tile subpinnae of L. microphyllum. It has a simple biology, with females and males produced throughout the year. Tile Population was female biased at 10.5 to 1. The immature development time was 8.9 ± 0.1 and 7.0 ± 0.1 days; adult longevity was 30.6 ± 1.6 and 19.4 ± 1.2 days and mean fecundity per female was 54.5 ± 3.2 and 38.5 ± 1.6 eggs at 21 and 26 ° C, all respectively. Field studies showed that tile mite was active year round, with populations peaking when temperatures were cool and soil moisture levels were highest. Two species of predatory mites, Tarsonemus sp. and a species of Tydeidae, along with the pathogen Hirsutella thompsonii, had significant effects oil all life stages of F. perrepae. Despite high levels of predators and the pathogen, F. perrepae caused consistent damage to L. microphyllum at all the field sites over the entire 2 years of the study.

The use of transcriptional profiles to predict adult mosquito age under field conditions

Age is a critical determinant of an adult female mosquito's ability to transmit a range of human pathogens. Despite its central importance, relatively few methods exist with which to accurately determine chronological age of field-caught mosquitoes. This fact is a major constraint on our ability to fully understand the relative importance of vector longevity to disease transmission in different ecological contexts. It also limits our ability to evaluate novel disease control strategies that specifically target mosquito longevity. We report the development of a transcriptional profiling approach to determine age of adult female Aedes aegypti under field conditions. We demonstrate that this approach surpasses current cuticular hydrocarbon methods for both accuracy of predicted age as well as the upper limits at which age can be reliably predicted. The method is based on genes that display age-dependent expression in a range of dipteran insects and, as such, is likely to be broadly applicable to other disease vectors.

Rising longevity, education, savings, and growth

This paper examines the impact of declines in adult mortality on growth in an overlapping generations model. With public education and imperfect annuity markets, a decline in mortality affects growth through three channels. First, it raises the saving rate and thereby increases the rate of physical capital accumulation. Second, it reduces accidental bequests, lowers investment, and thereby lowers the rate of physical capital accumulation. Third, it may lead the median voter to increase the tax rate for public education initially but lower the tax rate in a later stage. Starting from a high mortality rate as found in many Third World populations, the net effect of a decline in mortality is to raise the growth rate. However, starting from a low mortality rate such as is found in most industrial populations, the net effect of a further decline in mortality is to reduce the growth rate. The findings appear consistent with recent empirical evidence. (C) 2002 Elsevier Science B.V All rights reserved.

Adult language input in the early childhood educational setting

Age-related changes in the adult language addressed to children aged 2;0-4;0 years in polyadic conditions were investigated in Australian childcare centres. The language that 21 staff members addressed to these children was coded for multiple variables in the broad social categories of prosody, context, speech act and gesture. The linguistic components were coded within the categories of phonology, lexicon, morphology, syntax and referential deixis. Minimal age-related differences were found. Explanations for the similarity of the adult language input across the age groups within the early childhood educational environment, will be discussed

The potential of virulent Wolbachia to modulate disease transmission by insects

A virulent strain of Wolbachia has recently been identified in Drosophila that drastically reduces adult lifespan. It has been proposed that this phenotype might be introduced into insect disease vector populations to reduce pathogen transmission. Here we model the requirements for spread of such an agent and the associated reduction in disease transmission. First, a simulation of mosquito population age structure was used to describe the age distribution of mosquitoes transmitting dengue virus. Second, given varying levels of cytoplasmic incompatibility and fecundity effect, the maximum possible longevity reduction that would allow Wolbachia to invade was obtained. Finally, the two models were combined to estimate the reduction in disease transmission according to different introduction frequencies. With strong CI and limited effect of fecundity, an introduction of Wolbachia with an initial frequency of 0.4 could result in a 60–80% reduction of transmitting mosquitoes. Greater reductions are possible at higher initial release rates.

Reversible cardiomyopathy associated with acute inhaled marijuana use in a young adult

Marijuana is a frequently used recreational drug. We describe the first published case of marijuana related cardiomyopathy.

Extended delayed recall of AVLT word lists: Effects of age and sex on adult performance

An extension of a previous study of age and sex effects on verbal recall (Geffen, Moar, O'Hanlon, lark, & Geffen, 1990) examined forgetting of words over extended delays. The AVLT was administered to 201 normal adults (99 males, 102 females) ranging in age between 20 and 59 years. Recall was tested at intervals of 30 minutes, 24 hours, and 7 days after acquisition. Testing of the latter two intervals was conducted by telephone (Experiment 1, N = 177). After 30 minutes there was no significant loss of the 10 to 11 words retained from five acquisition trials. However, an overall mean of about one word was forgotten after 1 day and a further word after 7 days. The oldest age group (50-59 years) acquired fewer words and forgot more words than the younger groups. Females of all age groups performed slightly better than males at acquisition, at retention, and at recall after longer delays. A second experiment showed that telephone testing at the longer delay intervals was equivalent to testing face to face. These results extend the use of the AVLT by assessing memory decay beyond the immediate testing period. Telephone follow-up is a convenient and economical method of testing delayed recall.

The Modified Card Sorting Test: Test-retest stability and relationships with demographic variables in a healthy older adult sample

Objectives. To investigate the test-retest stability of a standardized version of Nelson's (1976) Modified Card Sorting Test (MCST) and its relationships with demographic variables in a sample of healthy older adults. Design. A standard card order and administration were devised for the MCST and administered to participants at an initial assessment, and again at a second session conducted a minimum of six months later in order to examine its test-retest stability. Participants were also administered the WAIS-R at initial assessment in order to provide a measure of psychometric intelligence. Methods. Thirty-six (24 female, 12 male) healthy older adults aged 52 to 77 years with mean education 12.42 years (SD = 3.53) completed the MCST on two occasions approximately 7.5 months (SD = 1.61) apart. Stability coefficients and test-retest differences were calculated for the range of scores. The effect of gender on MCST performance was examined. Correlations between MCST scores and age, education and WAIS-R IQs were also determined. Results. Stability coefficients ranged from .26 for the percent perseverative errors measure to .49 for the failure to maintain set measure. Several measures were significantly correlated with age, education and WAIS-R IQs, although no effect of gender on MCST performance was found. Conclusions. None of the stability coefficients reached the level required for clinical decision making. The results indicate that participants' age, education, and intelligence need to be considered when interpreting MCST performance. Normative studies of MCST performance as well as further studies with patients with executive dysfunction are needed.

Administration of growth hormone or IGF-I to pregnant rats on a reduced diet throughout pregnancy does not prevent fetal intrauterine growth retardation and elevated blood pressure in adult offspring

Increasing evidence from human epidemiological studies suggests that poor growth before birth is associated with postnatal growth retardation and the development of cardiovascular disease in adulthood. We have shown previously that nutritional deprivation in the pregnant rat leads to intrauterine growth retardation (IUGR), postnatal growth failure, changes in the endocrine parameters of the somatotrophic axis, and to increased blood pressure in later life. In the present study, we investigated whether administration of insulin-like growth factor-I (IGF-I) or bovine growth hormone (GH) during pregnancy could prevent IUGR and/or alter long-term outcome. Dams h-om day 1 of pregnancy throughout gestation received a diet of nd libitum available food or a restricted dietary intake of 30% of ad libitum fed dams. From day 10 of gestation, dams were treated for 10 days with three times daily subcutaneous injections of saline (100 mu l), IGF-I (2 mu g/g body weight) or GH (2 mu g/g body weight). Maternal weight gain was significantly increased (P

Effects of mate availability on female longevity, fecundity and egg development of Homichloda barkeri (Jacoby) (Coleoptera : Chrysomelidae)

This study examined the effect of the number of maternal matings on egg production, embryonic development and female longevity in Homichloda barkeri (Jacoby) (Cole optera: Chrysomelidae). Single-mated females lived longer than multiple-mated and unmated females. The number of eggs produced per day and the proportion of eggs that developed between single- and multiple-mated females was not affected by mating frequency.

The role of mobile belts for the longevity of deep cratonic lithosphere: The crumple zone model

Many Archean cratons are surrounded by Proterozoic mobile belts that have experienced episodes of tectonic re-activation over their lifetimes. This suggests that mobile belt lithosphere may be associated with long lived, inherited weakness. It is proposed that the proximity of this weakness can increase the longevity of deep Archean lithosphere by buffering Archean cratons from mantle derived stresses. The physical plausibility of this idea is explored through numerical simulations of mantle convection that include continents and allow for material rheologies that model the combined brittle and ductile behavior of the lithosphere. Within the simulations, the longevity of deep cratonic lithosphere does increase if it is buffered by mobile belts that can fail at relatively low stress levels.

Dynamic spatiotemporal expression patterns of neurocan and phosphacan indicate diverse roles in the developing and adult mouse olfactory system

The chondroitin sulfate proteoglycans neurocan and phosphacan are believed to modulate neurite outgrowth by binding to cell adhesion molecules, tenascin, and the differentiation factors heparin-binding growth-associated molecule and amphoterin. To assess the role of these chondroitin sulfate proteoglycans in the olfactory system, we describe here their expression patterns during both embryonic and postnatal development in the mouse. Immunoreactivity for neurocan was first detected in primary olfactory neurons at embryonic day 11.5 (E11.5). Neurocan was expressed by primary olfactory axons as they extended toward the rostral pole of the telencephalon as well as by their arbors in glomeruli after they contacted the olfactory bulb. The role of neurocan was examined by growing olfactory neurons on an extracellular matrix substrate containing neurocan or on extracellular matrix in the presence of soluble neurocan. In both cases, neurocan strongly promoted neurite outgrowth. These results suggest that neurocan supports the growth of primary olfactory axons through the extracellular matrix as they project to the olfactory bulb during development. Phosphacan, unlike neurocan, was present within the mesenchyme surrounding the E11.5 and E12.5 nasal cavity. This expression decreased at E13.5, concomitant with a transient appearance of phosphacan in nerve fascicles. Within the embryonic olfactory bulb, phosphacan was localised to the external and internal plexiform layers. However, during early postnatal development phosphacan was concentrated in the glomerular layer. These results suggest that phosphacan may play a role in delineating the pathway of growing olfactory axons as well as defining the laminar organization of the bulb. Together, the spatiotemporal expression patterns of neurocan and phosphacan indicate that these chondroitin sulfate proteoglycans have diverse in situ roles, which are dependent on context-specific interactions with extracellular and cell adhesion molecules within the developing olfactory nerve pathway. (C) 2000 Wiley-Liss, Inc.

Inability of adult Limnodynastes peronii (Amphibia : Anura) to thermally acclimate locomotor performance

Despite several studies on adult amphibians, only larvae of the striped marsh frog (Limnodynastes peronii) have been reported to possess the ability to compensate for the effects of cool temperature on locomotor performance by thermal acclimation. In this study, we investigated whether this thermal acclimatory ability is shared by adult L. peronii. We exposed adult L. peronii to either 18 or 30 degrees C for 8 weeks and tested their swimming and jumping performance at six temperatures between 8 and 35 degrees C. Acute changes in temperature affected both maximum swimming and jumping performance, however there was no difference between the two treatment groups in locomotor performance between 8 and 30 degrees C. Maximum swimming velocity of both groups increased from 0.62 +/- 0.02 at 8 degrees C to 1.02 +/- 0.03 m s(-1) at 30 degrees C, while maximum jump distance increased from similar to 20 to > 60 cm over the same temperature range. Although adult L. peronii acclimated to 18 degrees C failed to produce a locomotor response at 35 degrees C, this most likely reflected a change in thermal tolerance limits with acclimation rather than modifications in the locomotor system. As all adult amphibians studied to date are incapable of thermally acclimating locomotor performance, including adults of L. peronii, this acclimatory capacity appears to be absent from the adult stage of development. (C) 2000 Elsevier Science Inc. All rights reserved.

Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males

A randomised crossover dietary intervention study was performed to evaluate the effects of replacing meat protein in the diet with a soyabean product, tofu, on blood concentrations of testosterone, dihydrotestosterone, androstanediol glucuronide, oestradiol, sex hormone-binding globulin (SHBG), and the free androgen index (total testosterone concentration/SHBG concentration x 100; FAI). Forty-two healthy adult males aged 35-62 years were studied. Diets were isoenergetic, with either 150 g lean meat or 290 g tofu daily providing an equivalent amount of macronutrients, with only the source of protein differing between the two diets. Each diet lasted for 4 weeks, with a 2-week interval between interventions. Fasting blood samples were taken between 07.00 and 09.30 hours. Urinary excretion of genistein and daidzein was significantly higher after the tofu diet (P

Detecting insomnia: comparison of four self-report measures of sleep in a young adult population

The sensitivity and specificity of four self-report measures of disordered sleep - the Sleep Impairment Index (SII), the Sleep Disorders Questionnaire (SDQ), the Dysfunctional Beliefs and Attitudes About Sleep Scale (DBAS) and the Sleep-Wake Activity Inventory (SWAI) - were compared in subjects with insomnia and normal sleep. Nineteen young adult subjects met DSM-IV criteria for primary insomnia and another 19 were normal control subjects. Discriminatory characteristics of each measure were assessed using receiver operator characteristic curve analyses. Discriminatory power was maximised for each measure to produce cut-scores applicable for identification of individuals with insomnia. The DBAS, SII and SDQ psychiatric DIMS subscale were found to correlate, and discriminated well between the two groups. The SWAI nocturnal sleep subscale was not found to be an accurate discriminator. The results suggest differences in the measures in their ability to detect insomnia, and offer guidelines as to the optimal use of test scores to identify young adults suspected of insomnia.