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Imazethapyr, a post-emergent herbicide used in worldwide soybean and corn crops, induces genetic and biochemical alterations in aquatic vertebrates. This study examined the relationship between biomarkers at different organization levels and imazethapyr real-life route exposure in Boana pulchella adults. Frogs were exposed to imazethapyr-based formulation Pivot® H (10.59%) at concentrations representing possible acute routes: field runoff (S1:10 mg.L−1), exposure after direct foliar application (S2:100 mg.L−1) and during direct foliar application (S3:1000 mg.L−1). Post-exposure, endpoints levels were evaluated: organism alterations, biochemical activities and cytogenetic assays. Forty-eight hours post-exposure, antioxidant enzymes decrease, micronuclei induction and DNA damage were observed in all scenarios, while cholinesterase activity increase and body condition reduction were observed in frog-exposed to S3. Ninety-six hours post-exposure, frogs showed glutathione-S-transferase inhibition in S1, micronuclei induction in S2 and S3, and DNA-damage increase in S3. Herbicides routes of exposures in real-life could indicate that authorized applications have a risk to amphibian populations. [ABSTRACT FROM AUTHOR]

Imazethapyr is an herbicide that is used in a variety of crops worldwide, including soybean and corn. The aim of the present study was to evaluate the biomarkers responses of adult Leptodactylus latinasus exposed to the formulation Pivot® H (10.59% imazethapyr) in the laboratory at concentrations and under conditions that simulate two potential field exposure scenarios: an immersion in field runoff (Scenario 1: 10 mg/L) and a direct exposure to the droplets emitted by spray noozles (Scenario 2: 1000 mg/L). In both scenarios, the experimental procedure involved completely immersing the frogs over a period of 15 s. Different endpoints were evaluated at several ecotoxicological levels 48 and 96 h after the herbicide exposure. These included individual (biometric indices and behavior alterations), histological (liver pigments and lesions), biochemical (catalase, glutathione system and cholinesterase activities) and genotoxic effects (micronuclei induction and nuclear abnormalities). Forty-eight hours after imazethapyr exposure, frogs submitted to Scenario 1 presented an inhibition of liver glutathione-S-transferase activity, whereas histological alterations and increased hepatic cholinesterase levels were observed in frogs exposed under Scenario 2. Ninety-six hours after exposure to the imazethapyr formulation, frogs from the Scenario 1 treatment presented a decrease in liver melanin and hemosiderin, increased hepatic catalase activity and micronuclei induction. For their part, frogs exposed to Scenario 2 presented a decrease in the hepatosomatic index, an increase in liver alterations, melanin reduction and micronuclei induction. The multivariate analysis enables correlations to be made between biomarkers of different organizational level in exposed anurans. Our result indicates that real exposure to imazethapyr formulations under field conditions may pose a risk to Leptodactylus latinasus populations living in the agroecosystems. [ABSTRACT FROM AUTHOR]

1.Superparasitism influences the fitness of female parasitoids and their progeny, and increasing time interval between oviposition bouts generally reduces survival probabilities of the second clutch. However, the timing of superparasitism may, under certain conditions, favour the second clutch. 2. This study investigated the effects of superparasitism time intervals on survival and fitness of both clutches, allowing the egg parasitoid Trichogramma euproctidis to parasitise previously parasitised Ephestia kuehniella host eggs at different time intervals. 3. In short intervals (0–1 h), a significant advantage was found for the second clutch over the first clutch (93.1% survival). In contrast, the second clutch was outcompeted by the first clutch in 17–19 h and 27–29 h intervals. Females deposited their eggs into larvae (intraspecific hyperparasitism) in a 39–41 h interval with a probability of survival of 57.1%. Females mostly refused to hyperparasitise pupae (∼80% rejection at 124–126 h), and when they did, their progeny never survived. 4. Hyperparasitism significantly increased parasitoid mortality in both clutches from less than 20% (superparasitism only) to over 35%. 5. Except on newly laid eggs (0–1 h), superparasiting females were frequently observed attempting to stab immatures of all stages (from 36.4% to 89.4% of all ovipositions depending on treatment), but infanticide only appeared to succeed on larvae (39–41 h). 6. When the second clutch survived, emerging parasitoids were smaller than control individuals, probably due to resource depletion. 7. These results suggest that T. euproctidis females can detect that a host has been previously parasitised but they cannot perceive superparasitism time intervals. [ABSTRACT FROM AUTHOR]

The Nagoya Protocol is a supplementary agreement to the Convention on Biological Diversity that provides a framework for the effective implementation of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, including invertebrate biological control agents. The Protocol came into force on 12 October 2014, and requires signatories and countries acceding to the Protocol to develop a legal framework to ensure access to genetic resources, benefit-sharing and compliance. The biological control community of practice needs to comply with access and benefit sharing regulations arising under the Protocol. The IOBC Global Commission on Biological Control and Access and Benefit Sharing has prepared this best practices guide for the use and exchange of invertebrate biological control genetic resources for the biological control community of practice to demonstrate due diligence in responding to access and benefit sharing requirements, and to reassure the international community that biological control is a very successful and environmentally safe pest management method based on the use of biological diversity. We propose that components of best practice include: collaborations to facilitate information exchange about what invertebrate biological control agents are available and where they may be obtained; knowledge sharing through freely available databases that document successes (and failures); cooperative research to develop capacity in source countries; and transfer of production technology to provide opportunities for small-scale economic activity. We also provide a model concept agreement that can be used for scientific research and non-commercial release into nature where access and benefit sharing regulations exist, and a model policy for provision of invertebrate biological control agents to other parties where access and benefit sharing regulations are not restrictive or do not exist. [ABSTRACT FROM AUTHOR]

The ecology and management of boreal forest ecosystems are drawing greater attention worldwide as their importance is being increasingly recognized for carbon sequestration or for harbouring the world's largest remaining intact forests. Selection cuts have been introduced as a more socially acceptable silvicultural method to improve the maintenance of habitat structure and functions as they mimic aspects of boreal forest succession dynamics. Many studies have shown that selection cutting helps maintaining arthropod communities in mature forests, but few have examined the increased risks of damage by bark- and wood-boring insects in boreal forests of eastern North America. We used multidirectional flight-interception traps to quantify the response of these beetles to 25 and 40% selection cutting in a balsam fir-white birch forest of Québec, Canada. The abundance and species number of both cerambycid and scolytid beetles were 5-6 times larger in selectively cut stands than in controls the year following treatments. Analyses revealed that bark- and wood-boring beetles' response was mostly associated with increased canopy openness in selectively cut stands (and sun-exposed locations within them) and residual tree injuries caused by harvesting operations. These conditions attracted beetles such as Trypodendron lineatum (Scolytinae) and Rhagium inquisitor (Cerambycidae), two species known for their ability to attack weakened, dying and dead hosts. Most species were more abundant in selection cuts, except for Evodinus m. monticola (Cerambycidae) whose abundance was strongly reduced after treatment. Some beetles can have detrimental effects on residual trees and thus could reduce timber value, but most species found in treated stands do not represent a high risk for healthy trees. Thus, selection cuts do not seem favourable to the establishment of tree-killing beetles. However, as they were found more active/abundant after selection cutting, it would be wise to further study their population dynamics over mid- and long-term periods, along with the ecological and economic implications associated with this silvicultural treatment. [ABSTRACT FROM AUTHOR]

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Although phytoseiids are best known as predators of phytophagous mites and other small arthropods, several species can also feed and reproduce on pollen. In laboratory assays, we assessed the profitability of two types of dietary supplements (three pollen species-cattail, maize and apple-and eggs of the Mediterranean flour moth, Ephestia kuehniella) for the two species of predatory mites most commonly used as biocontrol agents in horticulture in Canada, Neoseiulus cucumeris and Amblyseius swirskii. We measured the effects of each diet on phytoseiid fitness parameters (survival, development, sex ratio, fecundity) and, as a means of comparison, when fed larvae of the common targeted pest species, western flower thrips Frankliniella occidentalis. A soluble protein assay was also performed on the alternative food sources as protein content is often linked to high nutritive value according to the literature. All food sources tested were suitable for N. cucumeris and A. swirskii, both species being able to develop from egg to adult. The dietary supplements had a beneficial impact on biological parameters, mostly resulting in shorter development times and higher survival rates when compared to thrips larvae. Amblyseius swirskii exhibited a wider dietary range than N. cucumeris. Overall, flour moth eggs, cattail pollen and apple pollen are food sources of equal quality for A. swirskii, whereas apple and cattail pollen are better when it comes to N. cucumeris. In contrast, maize pollen is a less suitable food source for N. cucumeris and A. swirskii. Soluble protein content results did not match the prediction under which the most beneficial food source would contain the highest concentration in protein. [ABSTRACT FROM AUTHOR]

It has been shown that pollen as a dietary supplement may increase the establishment (development and reproduction) and survival of phytoseiid predatory mites, and therefore the pest control these mites can provide. In this study, the role of apple pollen as a supplemental food source was assessed as a means to increase the efficiency of two predatory mite species, Neoseiulus cucumeris and Amblyseius swirskii, for control of western flower thrips, Frankliniella occidentalis, under greenhouse conditions. The impact of apple pollen on thrips populations and predator establishment on a greenhouse chrysanthemum crop was determined over a 4-week period. The two mite species were released separately and in combination with and without pollen with two control treatments (thrips only and thrips + pollen). The introduction of A. swirskii together with pollen application provided the best control of thrips (adults and immatures). The establishment of N. cucumeris was very low in the crop during the greenhouse trial. This could be attributable, in part, to their response to extreme temperature ranges that were encountered during the greenhouse cage trials. The use of A. swirskii alone and the mixed population of the two predatory mite species without pollen resulted in the lowest frequencies of plants with heavy damage, followed by the same treatments with the addition of apple pollen. [ABSTRACT FROM AUTHOR]

This study investigated differences in the magnitude and partitioning of the carbon (C) and greenhouse gas (GHG) balances in an age sequence of four white pine (Pinus strobus L.) afforestation stands (7, 20, 35 and 70 years old as of 2009) in southern Ontario, Canada. The 4-year (2004-2008) mean annual carbon dioxide (CO2) exchanges, based on biometric and eddy covariance data, were combined with the 2-year means of static chamber measurements of methane (CH4) and nitrous oxide (N2O) fluxes (2006-2007) and dissolved organic carbon (DOC) export below 1m soil depth (2004-2005). The total ecosystem C pool increased with age from 46 to 197 t C ha-1 across the four stands. Rates of organic matter cycling (i.e. litterfall and decomposition) were similar among the three older stands. In contrast, considerable differences related to stand age and site quality were observed in the magnitude and partitioning of individual CO2 fluxes, showing a peak in production and respiration rates in the middle-age (20-year-old) stand growing on fertile postagricultural soil. The DOC export accounted for 10% of net ecosystem production (NEP) at the 7-year-old stand but <2% at the three older stands. The GHG balance from the combined exchanges of CO2, CH4 and N2O was 2.6, 21.6, 13.5 and 4.8 t CO2 equivalent ha-1 year-1 for the 7-, 20-, 35- and 70-year-old stands, respectively. The maximum annual contribution from the combined exchanges of CH4 and N2O to the GHG balance was 13 and 8% in the 7- and 70- year-old stands, respectively, but <1% in the two highly productive middle-age (20- and 35-year-old) stands. Averaged over the entire age sequence, the CO2 exchange was the main driver of the GHG balance in these forests. The cumulative CO2 sequestration over the 70 years was estimated at 129 t C and 297 tC ha-1 year-1 for stands growing on low- and high-productivity sites, respectively. This study highlights the importance of accounting for age and site quality effects on forest C and GHG balances. It further demonstrates a large potential for net C sequestration and climate benefits gained through afforestation of marginal agricultural and fallow lands in temperate regions. [ABSTRACT FROM AUTHOR]

By definition, insect parasitoids kill their host during their development. Data are presented showing that ladybirds not only can survive parasitism by Dinocampus coccinellae, but also can retain their capacity to reproduce following parasitoid emergence. We hypothesize that host behaviour manipulation constitutes a preadaptation leading to the attenuation of parasitoid virulence. Following larval development, the parasitoid egresses from the host and spins a cocoon between the ladybird's legs. Throughout parasitoid pupation, the manipulated host acts as a bodyguard to protect the parasitoid cocoon from predation. The parasitoid has evolved mechanisms to avoid killing the host prematurely so that its own survival is not compromised. Bodyguard manipulation may thus constitute a selective trait for the evolution of true parasitism in some host-parasitoid associations. [ABSTRACT FROM AUTHOR]

Invasive alien species can act as 'evolutionary traps' for indigenous parasites and predators when the alien species is accepted as prey or a host but is unsuitable for consumption or development. We tested the relationship between acceptance and suitability of eggs of the invasive alien Halyomorpha halys (Hemiptera: Pentatomidae) in North America relative to eggs of the indigenous Podisus maculiventris (Pentatomidae) for the indigenous generalist egg parasitoid Telenomus podisi (Hymenoptera: Scelionidae). T. podisi accepted 0-24 h old H. halys eggs at a rate similar to P. maculiventris eggs (87.5 ± 6.0 and 70.2 ± 9.1 %, respectively). Successful development of T. podisi occurred in 98.3 % of attacked P. maculiventris eggs, but was not observed in H. halys eggs. Oviposition by T. podisi did, however, reduce the developmental success of H. halys embryos relative to unattacked controls by 24.1 % in 0-24 h old eggs and 29.6 % in 24-48 h old eggs. We suggest that as H. halys spreads and increases in abundance in North America, it could operate as an evolutionary trap for indigenous egg parasitoids, thereby indirectly causing an increase in population levels of indigenous pentatomids. This predicted indirect effect would be a result of H. halys eggs acting as an egg sink for T. podisi. We also introduce the concept of a 'time sink', which may be particularly relevant for parasitoids such as T. podisi that spend considerable time protecting their reproductive investments. [ABSTRACT FROM AUTHOR]

Host age is an important determinant of host acceptance and suitability for egg parasitoids. As host embryonic development advances, the quality of resources available to the parasitoid offspring typically declines, usually resulting in reduced acceptance levels by foraging females and lower offspring fitness. We examined the ability of the parasitoid Telenomus podisi Ashmead ( Hymenoptera: Scelionidae) to parasitize and develop in Podisus maculiventris ( Say) ( Hemiptera: Pentatomidae) eggs of different ages. In laboratory experiments, we measured the effect of host age (6, 24, 48, 72, 96, or 120 h old) on parasitism rate and offspring fitness parameters such as survival, development time, sex ratio, and size. Contrary to our expectations, parasitism rate did not differ between host age treatments, nor did sex ratio allocation, offspring size, or the fecundity of newly emerged female offspring. However, parasitoid offspring had a longer development time with increasing host age. This trend was stronger for males than for females, which we suggest could reduce the degree of protandry among offspring emerging from older host eggs, thus increasing the rate of virginity upon leaving the emergence patch and resulting in more frequent off-patch mating by female offspring in nature. Overall, our results suggest that all stages of P. maculiventris embryonic development are suitable for acceptance and development of T. podisi. Unlike most species of egg parasitoids, T. podisi has evolved mechanisms to utilize host resources, regardless of host developmental stage, with relatively minor fitness consequences. [ABSTRACT FROM AUTHOR]

The cabbage maggot, Delia radicum L., has a bimodal pattern of emergence caused by the presence in populations of early and late-emerging genotypes that differ in their pupal development time. These genotypes could also express different egg-laying strategies. To examine oviposition patterns between genotypes and, particularly, their response to temperature, the egg-laying activity of females and egg mortality from each genotype were evaluated at temperatures from 12 to 30°C. Several criteria were used to describe the oviposition pattern: longevity of females, preoviposition period, lifetime fecundity, number of oviposition bouts, duration and number of eggs for each oviposition bout, duration of an oviposition cycle, and time interval between oviposition bouts. All criteria were similar between genotypes, except the preoviposition period and time interval between oviposition bouts. The preoviposition period was 1-4 d longer for the early emerging genotype than for the late-emerging genotype at temperatures <25°C, but similar at temperatures ≥25°C. The time interval between oviposition bouts of early emerging genotype was a few hours longer than for the late-emerging genotype at all temperatures. All oviposition pattern criteria responded to temperature, except the duration of oviposition bouts (≈6.5 d) and egg mortality (≈11%). The duration of a bout could be a compromise between oogenesis duration and the risks associated with egg deposition. According to these results, early and late-emerging genotypes express similar egg-laying strategies for all temperatures tested. [ABSTRACT FROM AUTHOR]

The functional response is a key element of predator-prey interactions, and variations in its parameters influence interaction strength and population dynamics. Recent studies have used the equation of the metabolic theory of ecology (MTE) to quantify the effect of temperature on the parameter Th, called "handling time," and then predict the responses of predators and communities to climate change. However, our understanding of the processes behind Th and how they vary with temperature remains limited. Using a ladybeetle-aphid system, we compared estimates of Th to direct observations of handling time across a temperature gradient. We found estimated Th values to be greater than observed Th values, suggesting that prédation rate is not limited by the time available for handling prey. We next estimated the corrected digestion time, i.e., digestion time corrected for gut capacity, by subtracting observed to estimated Th values. We finally plotted the relationships between temperature and handling or digestion rates. As predicted by MTE, the corrected digestion rate increased exponentially with warming whereas, in contrast to MTE prediction, the relationship between handling rate and temperature was hump shaped. The parameter Th is thus confusing because it combines handling and digestive processes that have different thermal responses. This may explain why general patterns in the relationship between Th and temperature have been difficult to identify in previous studies. [ABSTRACT FROM AUTHOR]

Anthropogenic range expansion and cultural practices have modified the distribution, abundance and genetic diversity of domesticated organisms, thereby altering multitrophic assemblages through space and time. The putative Mesoamerican domestication centre of the common bean, Phaseolus vulgaris L., in Mexico allows investigating the effects of plant domestication on the genetic structure of members of a multitrophic system. The aim of this study was to compare the evolutionary history of Horismenus parasitoids (Hymenoptera: Eulophidae) to those of their bruchid beetle hosts (Coleoptera: Bruchidae) and their domesticated host plant (P. vulgaris), in the context of traditional agriculture in Mexico. We analyzed the population genetic structure of four Horismenus species in Mexico using mitochondrial COI haplotype data. The two most abundant parasitoid species were Horismenus depressus and Horismenus missouriensis. Horismenus missouriensis were infected by Wolbachia endosymbionts and had little to no population differentiation (FST = 0.06). We suspect the mitochondrial history of H. missouriensis to be blurred by Wolbachia, because differentiation among infected vs. non-infected individuals exists (FST = 0.11). Populations of H. depressus were found to be highly differentiated (FST = 0.34), but the genetic structuring could not be explained by tested spatial components. We then compared the genetic structure observed in this parasitoid species to previously published studies on bruchid beetles and their host plants. Despite extensive human-mediated migration and likely population homogenization of its two Acanthoscelides bruchid beetle hosts, H. depressus populations are structured like its host plant, by a recent dispersal from a diverse ancestral gene pool. Distinct evolutionary dynamics may explain inconsistent patterns among trophic levels. Parasitoids likely migrate from wild bean populations and are poorly adapted to bean storage conditions similar to their bruchid beetle hosts. Integrating several trophic levels to the study of evolutionary history has proven to be fruitful in detecting different ecological responses to human-mediated disturbances and host parasite interactions. [ABSTRACT FROM PUBLISHER]

We described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera: Calliphoridae) and their Nasonia (Ashmead) (Hymenoptera: Pteromalidae) parasitoids collected from tree swallow, Tachycineta bicolor (Vieillot), nests in southern Québec, Canada, in 2008 and 2009. The prevalence of nest infestation by ProtocaUiphora was 70.8% in 2008 and 34.6% in 2009. The average parasitic burden of Protocalliphora spp. was estimated at 5.53 (±5.61 SD) pupae per nestling for 2008 and 4.66 (±9.31 SD) pupae per nestling for 2009. The percentage of nests containing ProtocaUiphora pupae parasitized by Nasonia spp. was of 85.3% in 2008 and 67.2% in 2009. Three species of Protocalliphora were collected--Protocalliphora sialia Shannon & Dobroscky, Protocalliphora bennetti Whitworth, and Protocalliphora metallica (Townsend)--and two species of Nasonia, Nasonia vitripennis (Walker) and Nasonia giraulti Darling. This is the first record of P. bennetti and N. giraulti in the province of Québec. Our findings provide further evidence for observation made previously that altricial bird nests are more frequently and more heavily infested by blow flies in western than in eastern North America. Our data also suggest that more than a quarter of the tree swallow within the study area are exposed to high levels of ectoparasitism that could negatively affect their health. [ABSTRACT FROM AUTHOR]

Edaphic factors such as soil temperature and moisture influence soil-dwelling insects, whose most vulnerable stages typically are eggs and young larvae. In this study, the survival of eggs and first-instar larvae of the cabbage maggot, Delia radicum L., was measured under laboratory conditions after exposure to a range of soil temperatures and moistures. When eggs were exposed to constant temperature (20-29°C) and humidity (5-200% [wt:wt]), temperature had no significant effect on survival, whereas humidity <25% [wt:wt] caused egg mortality. The gradual exposure of eggs to high temperatures resulted in low mortality below 33°C, but <5% of eggs survived at 40°C. When first-instar larvae were exposed to constant temperature (17-29°C) and humidity (5-100% [wt:wt]), both factors as well as their interaction had a significant effect on larval survival, which was nil at 5% (wt:wt) for all temperatures but increased from 21.9 to 42.8% at 17°C and from 34.1 to 55.0% at 29°C, for soil moisture contents of 15% and 100% (wt:wt), respectively. Eggs of D. radicum are resistant to low soil moisture and high temperature conditions. Larval survival tends to increase with an increase in soil temperature and moisture. It is suggested that soil temperature be integrated into insect development simulation models instead of air temperature, to build more effective models for cabbage maggot management. [ABSTRACT FROM AUTHOR]

Intraguild predation (IGP) has been increasingly recognized as an important interaction in ecological systems over the past two decades, and remarkable insights have been gained into its nature and prevalence. We have developed a technique using molecular gut-content analysis to compare the rate of IGP between closely related species of coccinellid beetles (lady beetles or ladybirds), which had been previously known to prey upon one another. We first developed PCR primers for each of four lady beetle species: Harmonia axyridis, Coccinella septempunctata, Coleomegilla maculata and Propylea quatuordecimpunctata. We next determined the prey DNA detection success over time (DS50) for each combination of interacting species following a meal. We found that DS50 values varied greatly between predator-prey combinations, ranging from 5.2 to 19.3 h. As a result, general patterns of detection times based upon predator or prey species alone are not discernable. We used the DS50 values to correct field data to demonstrate the importance of compensation for detection times that are specific to particular predator-prey combinations. [ABSTRACT FROM AUTHOR]

It is well known that increasing the ambient temperature increases the metabolic rate and consequently, the foraging rate of most insects. However, temperature experienced during the immature stages of insects affects their adult size (an inverse relationship). Because body size is generally correlated to foraging success, we hypothesized that temperature indirectly influences the foraging efficiency of adult insects through developmental effects. We first investigated the role of parasitoid: host body size ratio on the handling time of Aphidius colemani (Viereck) (Hymenoptera: Braconidae), then tested the prediction that increasing temperature during immature development increases the handling time of adults. As expected, parasitoids took longer to handle large aphids than small aphids. However, large parasitoids did not have shorter handling times than small parasitoids except when attacking large (adult) aphids. Developmental temperature had the predicted effect on parasitoids: Individuals reared at 25°C were smaller than those insects reared at 15°C. Parasitoids reared at 15°C bad similar short handling times for both first instar and adult aphids, whereas parasitoids reared at 25°C took longer to handle adult aphids than first instar aphids. The size-mediated effect of temperature through development on parasitoid efficiency was opposite to the more familiar direct effect of temperature through metabolic rate. We conclude that the net effect of temperature on foraging insects will depend on its relative influence on immature and adult stages. [ABSTRACT FROM AUTHOR]

This paper examines the compensation process for work-related injuries and illnesses by assessing the trajectories of a sample of immigrant and non-immigrant workers ( n = 104) in Montreal. Workers were interviewed to analyze the complexity associated with the compensation process. Experts specialized in compensation issues assessed the difficulty of the interviewees’ compensation process. Immigrant workers faced greater difficulties with medical, legal, and administrative issues than non-immigrants did. While immigrant workers’ claim forms tended to be written more often by employers or friends (58% vs. 8%), the claims were still more often contested by employers (64% vs. 24%). Immigrant workers were less likely to obtain a precise diagnosis (64% vs. 42%) and upon returning to work were more likely to face sub-optimal conditions. Such results throw into relief issues of ethics and equity in host societies that are building their economy with migrant workers. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that host tree age may act as a selective factor and lead to local adaptation of the hemlock looper (Lambdina fiscellaria), a geometrid Lepidoptera that has a wide geographical distribution and has evolved in different eco-zones characterized by different levels of floristic composition, age structure and fragmentation level. Considering that hemlock looper outbreaks mainly occurred in old forests, we compared the biological performances of two populations. The first population was collected in the northern virgin boreal forest, which is dominated by mature and overmature coniferous stands that have not suffered from human disturbance. The other population was collected in the southern mixed-wood forest, which is more diversified and has been modified by forest harvesting. Larvae were reared under controlled conditions on foliage from three age classes of balsam fir trees: juvenile, mature and overmature. Although we measured significant variations of biological performances between the two populations, no significant effect of the age of the balsam fir trees could be detected for males from both populations or for females from the southern population. However, northern females were strongly affected by the age of balsam fir trees on which they fed, as their pupal weight was 12% higher and their fecundity increased by 27% on overmature trees compared with juvenile ones. These results indicate that under the same selective pressure, females adapt their strategy to maximize their fitness, and thus they appear as the driving force of evolution through the local adaptation concept. Furthermore, the two populations evolved in distinct habitats and their adaptation reflects selective pressures occurring inside their original environment. This is the first report on local adaptation of an herbivore that is mediated by host tree age. Changes in forest age structure may have a considerable impact on insect local adaptation and presumably on their population dynamics. [ABSTRACT FROM AUTHOR]

Oral diseases are highly prevalent among people on social assistance. Despite benefiting from public dental coverage in North America, these people rarely consult the dentist. One possible reason is rooted in their perception of oral health and the means to improve it. To respond to this question, largely unexplored, we conducted qualitative research through 8 focus groups and 15 individual interviews in Montreal (Canada). Thematic analysis revealed that people on social assistance: (a) define oral health in a social manner, placing tremendous value on dental appearance; (b) complain about the decline of their dental appearance and its devastating impact on self-esteem, social interaction, and employability; and (c) feel powerless to improve their oral health and therefore contemplate extractions and complete dentures. Our research demonstrates that perception of oral health strongly influences treatment preference and explains low and selective use of dental services in this disadvantaged population. [ABSTRACT FROM AUTHOR]

An ongoing debate in biological control consists of whether interference between biological agents can disrupt pest control. This study investigated the outcome of interactions between the entomopathogen Beauveria bassiana with the whitefly predator Dicyphus hesperus and the parasitoid Encarsia formosa, as well as their effect on the control of the greenhouse whitefly Trialeurodes vaporariorum on greenhouse tomato crops. Our objective was to determine whether the generalist B. bassiana would disrupt biological control by interfering with D. hesperus or E. formosa. In experimental greenhouses, whitefly, parasitoid and predator populations were established, and over 27 days, tomato plants were sprayed with three applications of the B. bassiana based product BotaniGard® (5.13×103 conidia/mm2) or water (control). Populations of greenhouse whitefly and biological control organisms were regularly monitored in control and B. bassiana-treated compartments. Overall, 10.6% of all whiteflies in treated compartments were infected, and 0.98% were both infected and parasitized. There were 31.7 and 22.3% fewer immature and adult whiteflies, respectively, on B. bassiana-treated plants relative to controls. Parasitism by E. formosa and predation by D. hesperus occurred at rates of 7.5 and 2.5%, respectively, in B. bassiana-treated compartments, and 5 and 6%, respectively in control compartments. Our study suggests that applications of B. bassiana for short-term biological control of greenhouse whiteflies are compatible with the concurrent use of E. formosa and D. hesperus on greenhouse tomato crops. [ABSTRACT FROM AUTHOR]

The main objective of this study was to assess the susceptibility of the black cutworm (Agrotis ipsilon) to the biopesticide spinosad and to a commercial formulation (GHA strain) of the entomopathogenic fungus, Beauveria bassiana. Secondly, we quantified the effects of sublethal doses of spinosad on a number of A. ipsilon fitness parameters, and interactions resulting from simultaneous applications of sub-lethal doses of spinosad and B. bassiana. Under laboratory conditions, A. ipsilon third instar larvae were highly susceptible to spinosad, with an estimated LC50 of 50 ppm. The entomopathogenic fungus, B. bassiana had a lower efficacy with an estimated LC50 of 7×107 spores mL-1. Topical applications of 5, 7.5 and 10 ppm of spinosad on third instar larvae reduced larval size and increased time to pupation and to emergence. However, pupal and adult weights were not significantly different between treated and control individuals. Additivity was observed from most spinosad-B. bassiana combinations tested, thus indicating compatibility between products. We concluded that spinosad is a promising tool for controlling black cutworm larvae alone or in combination with other products. [ABSTRACT FROM AUTHOR]

In short-term laboratory experiments, we studied the influence of light intensity, photoperiod, and temperature on the feeding and oviposition activity of two aphelinid parasitoids, Encarsiaformosa Gahan and Eretmocerus eremicus Rose and Zolnerowich, on the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). E. eremicus parasitized significantly more whitefly hosts than E. formosa in all treatment combinations of light intensity and photoperiod at 24 and 20°C. At 24°C, both E. formosa and E. eremicus parasitized approximately twice as many whitefly hosts at the high light intensity (112-114 W/m²)-long daylength (L 16:D 8 h) treatment than at the low light intensity (12-14 W/m²)-short daylength (L 8:D 16 h) treatment. In most instances at 20 and 24°C, significantly more dead whitefly hosts were recorded in leaf cages introduced with parasitoids than leaf cages with no parasitoids, indicating that host feeding occurred. Both E. formosa and E. eremicus parasitized significantly more whitefly hosts under the simulated summer (i.e., high light intensity [82.0-83.6 W/m²]; long daylength [L 16:D 8 h], 24°C) treatment than the winter (i.e., low light intensity [10.8-11.1 W/ m²]; short daylength [L 8:D 16 h], 20°C) treatment. In addition, significantly more dead whitefly hosts were observed in leaf cages introduced with E. eremicus than K formosa under the winter treatment, suggesting that E. eremicus killed more whitefly hosts through host feeding than E. formosa. This was not the case for the other treatment combinations. E. eremicus contributes more to greenhouse whitefly mortality than E. formosa by a combination of greater parasitism and host feeding and therefore is recommended for use in winter months with day temperatures ≥= 20°C, in addition to later in the season, where it is currently being used. [ABSTRACT FROM AUTHOR]

Classical biological control of insect pests and weeds may lead to potential conflicts, where insect pests are closely related to weed biological control agents. Such a conflict may occur in the classical biological control of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) in North America, which belongs to the same subfamily, Ceutorhynchinae, as a number of agents introduced or proposed for introduction against non-indigenous invasive weed species. We propose a step-by-step procedure to select non-target species and thereby to develop a non-target species test list for screening candidate entomophagous biological control agents of a herbivore pest insect in a way that would simultaneously evaluate non-target potential on weed biological control agents and other non-target species. Using these recommendations, we developed a non-target test list for host specificity evaluations in the area of origin (Europe) and the area of introduction (North America) for cabbage seedpod weevil parasitoids. Scientifically based predictions on expected host–parasitoid interactions and ecological information about the ecological host range in the area of origin can help avoid conflicts, while still allowing the introduction of safe and effective agents against both insect pests and weeds. [ABSTRACT FROM AUTHOR]

The life-course framework stresses the importance of social, psychosocial, and biological factors in early life on the development of later disease. From this perspective, the association between edentulousness of mothers and their children's caries risk has not been studied. Therefore, a sample of 6303 mother-child pairs was randomly selected in Quebec (Canada). Mothers (6039 dentate and 264 edentulous) completed a selfadministered questionnaire, and their children, aged 5 to 9 years, were clinically examined. Bivariate analyses and multiple logistic regressions showed that edentulous mothers' children are more likely to experience caries on both primary [OR = 1.7 (1.3-2.3)] and permanent [OR = 1.4 (1.0-2.0)] dentitions when compared with dentate mothers' children. These results are independent of socio-economic status, age, gender, and children's oral-health-related behaviors. Our study is the first to show that edentulous mothers' children constitute a group at risk of caries. It also highlights the need for a better understanding of the mother-child transmission of risk. [ABSTRACT FROM AUTHOR]

Research has shown that preventive and health promotion (PHP) services offered by community health centres are often vulnerable in times of health reform or budgetary cutbacks. The present study was conducted in Quebec, Canada, approximately 10 years after the start of a major transformation of health care services. The objectives were: (1) to examine the diversity of infant/toddler prevention and health promotion services offered by centres locaux de services communautaires (CLSCs, local community health and social services centres); and (2) to investigate the organisational and environmental correlates of such diversity. All Quebec CLSCs were invited to complete a survey questionnaire regarding their PHP services (response rate = 69%). Data on environmental and organisational factors were extracted from existing Quebec government data sets. Bivariate and multivariate analyses were performed to identify the correlates of the CLSCs' level of diversity of PHP services. The results revealed that CLSCs varied greatly in terms of their diversity of PHP services. The number of full-time equivalents in the Child and Family Services Programme (one of two programmes aimed at reaching the targeted clientele) and the degree of CLSC collaboration with other community-based organisations in the planning and delivery of PHP activities were positively associated with the level of diversity, whereas the unemployment rate in the population served was a negative predictor. This study makes an important contribution in being one of the very few which contribute to building our knowledge about the performance of community health centres. Identifying the correlates of diversity among PHP services offered by CLSCs helps us to begin to understand the processes at work in the production of PHP activities, as well as the potential leveraging forces. [ABSTRACT FROM AUTHOR]

In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species:Dendrocerus carpenteri(Curtis) (Hymenoptera: Megaspilidae),Asaphes suspensusWalker (Hymenoptera: Pteromalidae),Alloxysta victrix(Westwood) (Hymenoptera: Alloxystidae) andSyrphophagus aphidivorus(Mayr) (Hymenoptera: Encyrtidae), to correlate their response to different cues with their ecological attributes such as host range and host stage. In addition, we compared our results with studies of primary parasitoids on the same plant–herbivore system. First, the olfactory response of females was tested in a Y-tube olfactometer (single choice: plant, aphid, honeydew, parasitised aphid, aphid mummy, or virgin female parasitoid; dual choice: clean plant, plant with aphids, or plant–host complex). Second, their foraging behaviour was described on plants with different stimuli (honeydew, aphids, parasitised aphids, and aphid mummies). The results indicated that olfactory cues are probably not essential cues for hyperparasitoid females. In foraging behaviour on the plant, all species prolonged their total visit time and search time as compared to the control treatment (clean plant). OnlyA. victrixdid not react to the honeydew. Oviposition in mummies prolonged the total visit time because of the long handling time, but the effect of this behaviour on search time could not be determined. No clear correlation between foraging behaviour and host stage or host range was found. In contrast to specialised primary aphid parasitoids that have strong fixed responses to specific kairomones and herbivore-induced synomones, more generalist aphid hyperparasitoids seem to depend less on volatile olfactory stimuli, but show similarities with primary parasitoids in their use of contact cues while searching on a plant. [ABSTRACT FROM AUTHOR]

1. Theoretical models predict that ovipositional decisions of parasitoid females should lead to the selection of the most profitable host for parasitoid development. Most parasitoid species have evolved specific adaptations to exploit a single host stage. However, females of the aphid hyperparasitoid Syrphophagous aphidivorus (Mayr) (Hymenoptera: Encyrtidae) display a unique and atypical oviposition behaviour by attacking either primary parasitoid larvae in live aphids, or parasitoid pupae in dead, mummified aphids. 2. in the laboratory, the correlation between host suitability and host preference of S. aphidivorus on the host Aphidius nigripes Ashmead parasitising the aphid Macrosiphum euphorbiae (Thomas) was investigated. 3. The relative suitability of the two host stages was determined by measuring hyperparasitoid fitness parameters (survival, development time, fecundity, sex ratio, and adult size of progeny), and calculating the intrinsic rate of population increase (rm). Host preference by S. aphidivorus females and the influence of aphid defence behaviour on host selection was also examined. 4. Hyperparasitoid offspring performance was highest when developing from hosts in aphid mummies and females consistently preferred this host to hosts in parasitised aphids. Although aphid defensive behaviour may influence host selection, it was not a determining factor. Ecological and evolutionary processes that might have led to dual oviposition behaviour in S. aphidivorus are discussed. [ABSTRACT FROM AUTHOR]

Foraging in many insect parasitoids is mediated by chemicals associated with hosts. For example, honeydew, the feces of feeding aphids, induces and/or prolongs searching behavior of aphid parasitoids. In the laboratory, we tested if aphid hyperparasitoids, which belong to a higher trophic level, also rely on aphid honeydew to locate their hosts. We used the potato aphid, Macrosiphum euphorbiae, the primary parasitoid, Aphidius nigripes, and four hyperparasitoids, Asaphes suspensus, Dendrocerus carpenteri, Alloxysta victrix, and Syrphophagus aphidivorus that possess different biological attributes and host ranges. We determined if foraging hyperparasitoid females could discriminate between (i) honeydew from a host and a non-aphid host (the potato aphid and the soft brown scale, Coccus hesperidum), and (ii) honeydew from healthy aphids and those parasitized by A. nigripes. Females of A. suspensus did not react to any of the honeydew treatments. While the presence of non-aphid honeydew did not modify the behavior of A. victrix, D. carpenteri, and S. aphidivorus females, they exhibited an increase in searching time and path length but not walking speed when in the presence of honeydew from aphids. However, there were no changes in host searching behaviors, such as antennation or ovipositor probing that have been reported for primary aphid parasitoids. There was no difference in the response of hyperparasitoid females to honeydew from healthy and parasitized aphids. These results indicate that hyperparasitoids may use aphid honeydew, a conspicuous cue from the second trophic level, as an infochemical to locate their hosts. [ABSTRACT FROM AUTHOR]

Many carnivorous arthropods use herbivore-induced plant volatiles to locate their prey. These plant volatiles are blends of up to hundreds of compounds. It is often unknown which compounds in such a complex volatile blend represent the signal to the foraging carnivore. We studied the role of methyl salicylate (MESA) as part of the volatile blend in the foraging behavior of the predatory mite Phytoseiulus persimilis by using a Y-tube olfactometer. MeSA is one of the compounds released by lima bean, infested with Tetranychus urticae—a prey species of the predatory mite. MeSA attracted satiated predatory mites in a dosedependent way with optimum attraction at a dose of 0.2 µg. Predatory mites did not discriminate between a prey-induced lima bean volatile blend (that contains MESA) and a prey-induced volatile blend to which an extra amount of synthetic MeSA had been added. However, they preferred a MeSA-containing volatile blend (induced by T. urticae) to an otherwise similar but MeSA-free blend (induced by jasmonic acid). Adding synthetic MeSA to the MeSA-free blend significantly increased the mites' choice for this odor, suggesting an important role for MESA. This study is a new step toward unraveling the role of herbivoreinduced plant volatiles in the foraging behavior of predatory arthropods. [ABSTRACT FROM AUTHOR]

We examined under laboratory conditions the thermopreference of the migratory locust, Locusta migratoria migratorioides, following infection by the entomopathogenic fungus Metarhizium anisopliae var. acridum and its influence on mycosis. Infected locusts raised their body temperature more frequently than healthy conspecifics through selection of high temperatures in a heat gradient. Thermoregulation did not, however, alter the frequency of feeding events nor the amount of food eaten by infected L. migratoria. A thermoregulation regime of a minimum of 4 h/day substantially increased survival of inoculated insects (by 85%). However, the therapeutic effect decreased when thermoregulation was delayed following inoculation of the pathogen. Thermoregulation reduced locust mortality but did not completely eliminate the fungus from infected hosts; the fungus grew and killed the insects when thermoregulation was interrupted. We suggest that periodic, short bouts of thermoregulation, when performed from the onset of infection and for an extended period of time, are sufficient to provide a therapeutic effect to infected hosts. Such thermoregulatory capacity of locusts may limit the potential of fungal pathogens as biological control agents under certain ecological conditions. [ABSTRACT FROM AUTHOR]

AIMS: To evaluate the associations between methadone and high-dose buprenorphine maintenance treatment and illicit drug use and injection among drug users in France. DESIGN: A cross-sectional study. Data were gathered using a questionnaire administered containing closed-ended questions. SETTING: Drug dependence clinics (DDC) and general practitioners' (GPs) offices in three French cities. PARTICIPANTS: Drug users undergoing maintenance treatment with methadone (n = 197) and buprenorphine (n = 142). MEASUREMENTS: Interviews covered the use of illicit drugs (heroin, cocaine or crack) and injection practices (illicit drugs and/or substitution drugs) during the last month, current treatment modalities, socio-demographic and health characteristics. Bivariate analysis and multivariate logistic regressions were conducted. FINDINGS: Overall, 35.4% of respondents (34.5% in the methadone group, 36.6% in the buprenorphine group, P= 0.69) had used at least one illicit drug, 25.7% reported having injected drugs and 15.3% had injected the substitution drug. Injection was more common among buprenorphine-maintained individuals (40.1%) than among users on methadone (15.2%) (P < 0.01). Multivariate analyses indicate that the type of substitution drug (buprenorphine versus methadone) was not associated with illicit drug use (OR = 1.1; 95% CI = 0.7-1.8). In the buprenorphine group, injection was related independently to social situation, as measured by housing (unstable versus stable housing, OR = 4.3; 95% CI = 1.6-11.5), but this was not the case in the methadone group. The risk of injection increased with buprenorphine dosage (high/low dosage OR = 6.2; 95% CI = 2.0-19.7), but this association was not observed in the methadone group. CONCLUSION: Further studies comparing the benefits of these two types of treatment should be carried out, taking outcomes such as physical health, mental health and social functioning into consideration. [ABSTRACT FROM AUTHOR]

Oxygen consumption and ammonia excretion of the Antarctic fish Notothenia coriiceps (18·4 cm LF) increased respectively two and fourfold above fasting levels 24 h after feeding with a single meal of shrimps (5·5 to 7·5% of body mass), and remained elevated for 120 h. In fasted fish, c-met positive cells in the fast muscle represented 5·5% of the total number of myonuclei. The number of c-met positive cells staining for the proliferating cell nuclear antigen was increased by 60% both 24 and 96 h after the meal, while the number of cells expressing the myogenic transcription factor, MyoD, was increased by 20% after 24 h, and by 44% after 96 h. The total numbers of c-met positive cells and cells expressing myogenin were not significantly altered 96 h following feeding. The results are consistent with an activation of myogenic progenitor cells proliferation by feeding but suggest a relatively long cell cycle time. Copyright 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved [Copyright &y& Elsevier]

One of the main problems for aged people is that of having a balanced diet, improved by correct conditioning of the alimentary bolus. Does the masticatory status influence the appearance of gastrointestinal disorders? Such a question justifies the present study. The present work concerned all the patients (211) of eight geriatric institutions, and was completed by a retrospective approach (case–control study). The main result brought by the case–control study, showed that poor oral functional characteristics represent a risk for gastrointestinal pathology (age being neutralized; odds ratio (OR): 2.62). This result indicates that the loss of teeth must be compensated by functionally effective dentures. Not only will the patients’ physical and psychic health improve but also medical and public health problems will be solved. [ABSTRACT FROM AUTHOR]

Male factor infertility patients can have anomalies in their sperm nuclei, displaying high levels of loosely packaged chromatin and damaged DNA. The primary objectives of this study were to compare the extent of DNA fragmentation in the spermatozoa of healthy light and heavy smokers versus non-smokers, and to investigate its correlation with concentrations of the smoking markers cotinine and cadmium. A secondary objective was to compare the concentrations of blood cadmium and serum cotinine with corresponding concentrations in seminal plasma. Ninety-seven healthy male volunteers were divided into three groups: non-smokers, light and heavy smokers. There was no difference between the three groups with respect to age, number of ejaculations per week, serum testosterone concentration, and parameters of semen analysis. The percentages of DNA fragmentation in spermatozoa were not statistically different in the heavy smokers (12.11%), light smokers (11.66%) and non-smokers (20.41%). Serum and seminal plasma concentrations of cotinine were significantly higher in heavy smokers compared with the other groups (P < 0.0001). Median values for blood cadmium concentration were higher in heavy smokers (4.50 microg/l) than in light smokers (0.20 microg/l) and non-smokers (0.20 microg/l) (P < 0.001). Cadmium concentration in seminal plasma was significantly higher in heavy smokers (0.20 microg/l) than in light smokers (0.10 microg/l) and non-smokers (0. 10 microg/l) (P < 0.05). In summary, our results indicate no association between smoking and DNA fragmentation in the spermatozoa of healthy men. [ABSTRACT FROM AUTHOR]

This study evaluates the suitability of using urinary excretion of o-cresol (o-CR) as a biological marker of occupational exposure to various concentrations of toluene (TOL). Thirty-eight individuals from three plants involved in the manufacture of paints or inks agreed to participate in the environmental and biological monitoring evaluations, which lasted one to two days. In all, 62 measurements of environmental TOL and urinary o-CR and hippuric acid (HA) levels were made. The eight-hour TOL exposure (time-weighted average [TWA]) ranged from 0 to 111 ppm, depending on plant and job title. TOL exposure was well correlated to post-shift urinary o-CR (r=0.89) and HA (r=0.67) levels. At low exposure levels (below 50 ppm), however, o-CR shows a stronger correlation (r=0.71) than HA (r=0.24). Based on our results, occupational exposure to 50 ppm of TOL would result in end-of-shift urinary o-CR concentration of 0.72 mu mol/mmol creatinine (0.69 mg/L, assuming a urinary creatinine concentration of 1 g/L). This value is of the same order of magnitude as the level proposed by the American Conference of Governmental Industrial Hygienists (ACGIH) in 1998 for exposure to 50 ppm of TOL, namely 0.5 mg/L. Our results suggest thatthe level of urinary o-CR is a more sensitive index of exposure to low concentrations of TOL than is the urinary concentration of HA. [ABSTRACT FROM AUTHOR]

The objective of the present study was to compare the influence of various binary mixtures containing ethylbenzene (EBZ), toluene (TOL) or xylene (XYL) administered by inhalation, with the influence exerted by a ternary mixture, on the kinetics of these solvents in blood. Groups of four rats were exposed for 4 h to TOL, XYL and EBZ, singly or in combination. The concentration of TOL, XYL and EBZ in blood was measured at various times (5, 30, 60, 90 and 120 min) following the end of exposure and the areas under the blood concentration curves (AUC) were calculated. Results showed that exposures to binary and ternary mixtures resulted in significantly higher ( P<0.05) blood concentrations of unchanged solvents as a result of metabolic interaction between these solvents. When the comparison was based on individual solvents, there was no difference between effect exerted by the ternary mixture and the binary mixtures, except for one. However, a comparison based on the total concentration of unchanged solvents disclosed that exposure to the ternary mixture resulted in greater interactive effects (3.17-fold increase) than exposures to binary mixtures (1.97-fold increase), whereas four out of six binary mixtures produced higher total levels of unchanged solvents in blood compared to the ternary mixture. This study shows that the greater risk of toxicity often thought to be associated with exposures to complex mixtures should not only be related to the magnitude of interactive effects among components (i.e., degree of mutual metabolic interaction) resulting from combined exposures, but also should take into account, as is universally recognized, the internal total dose of toxic chemicals in target organs/tissues. [ABSTRACT FROM AUTHOR]

Co-trimoxazole was compared with nafcillin against Staphylococcus aureus in vitro and in the therapy of experimental Staph. aureus meningitis in rabbits. Co-trimoxazole (trimethoprim:sulphamethoxazole in a 1:20 ratio) was synergistic against 22/24 strains of Staph. aureus in vitro. The MBC90 of co-trimoxazole and nafcillin were 0.156-3.12 mg/l and 0.25 mg/l, respectively, concentrations below those achievable in purulent cerebrospinal fluid. The rate of bacterial killing (Staph. aureus) by co-trimoxazole and nafcillin were similar in both broth and pooled CSF in vitro. However, the MBC increased and the rate of bactericidal activity of both agents declined when tested in CSF at a higher inoculum (10(7) cfu/ml). During continuous intravenous infusion therapy of a reproducible, uniformly fatal (if untreated) model of experimental Staph. aureus meningitis, serum concentrations of all agents closely approximated those found in humans receiving standard parenteral regimens. The mean percent penetration into CSF ([CSF]/[serum] X 100) was 2.9, 35.6 and 27.1% for nafcillin, trimethoprim and sulphamethoxazole, respectively. Although both nafcillin and co-trimoxazole therapy reduced CSF Staph. aureus concentrations significantly more rapidly (P less than 0.001) when compared to untreated controls, the bactericidal rate was modest. The CSF was rendered sterile in 0/64 animals treated with either regimen for 8 h. Nafcillin was more rapidly bactericidal in vivo (P less than 0.03) than co-trimoxazole in this model. Caution is advised in the use of co-trimoxazole for infections of the central nervous system caused by Staph. aureus. [ABSTRACT FROM AUTHOR]

This study was undertaken to determine whether previous subacute treatment with ethanol could modify the kinetics of m-xylene in humans. A group of six volunteers was exposed twice to either 100 or 400 ppm of m-xylene during two hours (between 0800 and 1000). Ethanol was given orally in the early evening on each of two consecutive days before exposures (total ethanol intake of 137 g). Such ethanol pretreatment affected the kinetics of m-xylene but only at the high exposure (400 ppm). The modifications were: (1) decreased concentration of m-xylene in blood and alveolar air during and after exposure; (2) increased urinary excretion of m-methylhippuric acid at the end of exposure. Ethanol treatment also enhanced the elimination of antipyrine in saliva. Overall, this study showed that the effect of enzyme induction on the metabolism of m-xylene, after ethanol ingestion, depends on the exposure concentration and is not likely to occur as long as the exposure concentrations remain under the current maximum allowable concentration (100 ppm) in the workplace. [ABSTRACT FROM AUTHOR]

The increase of dental fluorosis is largely imputable to the ingestion of dietary fluoride supplements and fluoride toothpastes. However, the toothbrushing habits of very young children is poorly documented. The purpose of this pilot study was to determine the toothbrushing habits of 12- to 24-month-old children and to estimate the quantity of fluoride ingested during toothbrushing. Fifty-nine parents completed a questionnaire regarding the toothcleaning habits of their children. When a dentifrice was used, a dental hygienist scheduled a meeting with the parents in order to observe and measure the amount of toothpaste used. Of the 36 parents who cleaned the teeth of their children, 69% used a toothpaste. Furthermore 20% of the children ingested more than 0.25 mg of fluoride per day by toothbrushing alone. Therefore the practice of toothbrushing and the use of fluoridated dentifrices are widespread among 12- to 24-month old children, and the amount of fluoride ingested from toothpaste could constitute a substantial proportion of the total daily intake of fluoride. Several measures are suggested to enhance the safe use of fluoride dentifrices. [ABSTRACT FROM AUTHOR]

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