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Background: Pulses are an integral component of food in India which acts as major source of protein required for growth and maintenance of body. But during their storage they suffer heavy losses resulting in depletion of their quality and edibility. The present studies focused on disinfestation of green gram grains using microwaves as an alternative approach to chemical methods for controlling insects in grains and pulses. Methods: In this laboratory studies during 2017-18, the grains of green gram were infested with different life stages of the cowpea weevil and exposed to 200, 400, 600 and 800 W microwave power levels, each at an exposure period of 10, 20, 30 and 40 s. Result: Eggs were the most susceptible, while pupal and adults were the least susceptible life stages to microwave treatments. Complete mortality of eggs was achieved with microwave treatments (400, 600 and 800 W), each at an exposure period of 30 and 40 s. Complete inhibition of larval stage was attained with 400 and 600 W (30 and 40 s) and 800 W (20, 30 and 40 s exposure) while for pupal stage it was observed at the higher wattages of 600 (40 s exposure) and 800 (30 and 40 s exposure). Microwave wattage of 600 W for 40 sand 800 W for 30 and 40 s exposure caused 100% mortality of 2d old adults of cowpea bruchid. [ABSTRACT FROM AUTHOR]

Objectives: (1) To explore the influence of biofilm maturation and timing of exposure on fluoride anticaries efficacy and (2) to explore biofilm recovery post-treatment. Methods: Bovine enamel specimens were utilized in a pH cycling model (28 subgroups [n = 18]). Each subgroup received different treatments [exposure]: sodium fluoride [NaF]; stannous fluoride [SnF2]; amine fluoride [AmF]; and de-ionized water [DIW], at a specific period: early: days 1–4; middle: days 3–6; and late: days 7–10. During non-exposure periods, pH cycling included DIW instead of fluorides. Objective 1: part 1 (cycling for 4, 6, or 10 days). Part 2 (cycling for 10 days). Objective 2: early exposure: three sample collection time points (immediate, 3 days, and 6 days post-treatment); middle exposure: two sample collection time points (immediate, 4 days post-treatment). The enamel and biofilm were analyzed ([surface microhardness; mineral loss; lesion depth]; [lactate dehydrogenase enzyme activity; exopolysaccharide amount; viability]). Data were analyzed using ANOVA (p = 0.05). Results: Objective 1: Early exposure to fluorides produced protective effects against lesion progression in surface microhardness and mineral loss, but not for lesion depth. Objective 2: Early exposure slowed the demineralization process. SnF2 and AmF were superior to NaF in reducing LDH and EPS values, regardless of exposure time. They also prevented biofilm recovery. Conclusion: Earlier exposure to SnF2 and AmF may result in less tolerant biofilm. Early fluoride treatment may produce a protective effect against demineralization. SnF2 and AmF may be the choice to treat older biofilm and prevent biofilm recovery. Clinical relevance: The study provides an understanding of biofilm-fluoride interaction with mature biofilm (e.g., hard-to-reach areas, orthodontic patients) and fluoride's sustainable effect hours/days after brushing. [ABSTRACT FROM AUTHOR]

A possible role of PM 2.5 components on ovarian reserve has not been adequately unexplored. To evaluate the association between PM 2.5 components and women' ovarian reserve over critical exposure periods in northern China, where the level of air pollution is among the nation's highest. We included 15,102 women with serum anti-Müllerian hormone (AMH) measurements from the Center for Reproductive Medicine of Shandong University during 2015–2019. Concentrations of PM 2.5 and its five major components (0.1° × 0.1°), including sulfate, nitrate, ammonium, organic matter, and black carbon, were assigned to each residential address. Multivariable linear mixed effect models combined with constituent-residual models were performed to estimate the effect sizes of essential components over six short- to long-term exposure periods. The strength of association was stronger during the process from primary to small antral follicle compared with other longer windows. For every interquartile range increase in PM 2.5 mass was associated with − 8.7% (95%CI: −12.3%, −4.9%) change in AMH and the effect size was greatest for sulfate. Women with the lower level of attained education and those living inland were more susceptible compared with other population subgroups. Exposure to specific components of air pollution during critical exposure windows is associated with a decline in ovarian reserve. These data add to the growing body of evidence that environmental factors have adverse effects on reproductive health, particularly for vulnerable population subgroups. [Display omitted] • Short-term exposure to ambient PM 2.5 mass and its five major components was associated with decreased ovarian reserve. • SO 4 2- was identified as having the strongest adversed effects on ovarian reserve. • Lower educated women or those living inland were more vulnerable to PM 2.5 mass and its components than others. [ABSTRACT FROM AUTHOR]

Background The relationship between PM2.5 exposure and preterm birth remains unclear. Objectives To explore the effect of exposure to PM2.5 on preterm birth in China. Methods The birth outcomes of 426,246 pregnant women enrolled between January 2014 and December 2014 in NFPCP (National Free Pre-pregnancy Checkups Project) were collected, and their individual PM2.5 exposure values were estimated from the China National Environmental Monitoring Centre. The time of gestational exposure to PM2.5 was divided into four periods (the first trimester, the second trimester, the third trimester and the entire pregnancy). The average concentration and the corresponding quartiles of PM2.5 were calculated in these periods by the daily average PM2.5 data. Cox proportional hazards regression was used and he effects of maternal age, education level, occupation, second-hand smoking, alcohol use, pre-pregnancy BMI, baby's sex, number of previous pregnancies, coastal areas and season of conception were adjusted for. Results A total of 426,246 singleton births were included, among which 35,261 (8.3%) were preterm birth. Effect of each 10 μg/m 3 increase of PM2.5 on preterm birth was most significant during the third trimester (HR, 1.06; 95%CI, 1.06–1.07), and also significant during the first trimester (HR, 1.04; 95%CI, 1.03–1.04), the second trimester (HR, 1.02; 95%CI, 1.02–1.02) and the entire pregnancy (HR, 1.06; 95%CI, 1.05–1.06). Compared with the lowest quartile of PM2.5, other quartiles increased the risk of preterm birth, and were most significant during the third trimester (HR, 1.87; 95%CI, 1.69–2.06). Subgroup analysis showed that compared with other subgroups, women who were older than 30 years, had low education level, worked as farmers, had male baby, had previous pregnancies, not live in coastal areas and pregnant in winter were more sensitive to PM2.5 exposure. Conclusions Ambient PM2.5 exposure during pregnancy played an important role in the pregnancy process and increased the risk of preterm birth. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag NPs) exponential production raises concern about their environmental impact. The effects of Ag NPs to aquatic plants remain scarcely studied, especially in extended exposures. This paper aims to evaluate Ag NPs effects in Lemna minor at individual and sub-individual levels, focusing on three variables: Ag form (NPs versus ions – Ag + ), NPs surface coating (citrate vs polyvinylpyrrolidone – PVP) and exposure period (7 vs 14 days). Endpoints were assessed at individual level (specific growth rate, chlorosis incidence and number of fronds per colony) and sub-individual level (enzymatic activities of catalase (CAT), guaiacol peroxidase (GPx) and glutathione-S-transferase (GST)). Generally, plants exposed to all Ag forms underwent decays on growth rate and fronds per colony, and increases on chlorosis, GPX and GST, but no effects on CAT. The most sensitive endpoints were specific growth rate and GPx activity, showing significant effects down to 0.05 mg/L for Ag NPs and 3 μg/L for Ag + , after 14 days. Ag + showed higher toxicity with a 14d–EC 50 of 0.0037 mg Ag/L. Concerning surface coating, PVP-Ag NPs were more deleterious on growth rate and fronds per colony, whereas citrate-Ag NPs affected more the chlorosis incidence and GPx and GST activities. The exposure period significantly affected chlorosis: 14 days triggered a chlorosis increase in Ag + -exposed plants and a decrease in Ag NPs-exposed plants when compared to 7 days. Ag NPs induced an oxidative stress status in cells, thus ensuing upregulated enzymatic activity as a self-defense mechanism. Since Ag NPs dissolution might occur on a steady and continuous mode along time, and the average longevity of fronds, we propose longer exposures periods than the recommended by the OECD guideline. This approach would provide more relevant and holistic evidences on the overall response of freshwater plants to Ag NPs in an ecological relevant scenario. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to investigate the effects of phthalate exposure on the intelligence and attentional performance of 6-year old children when adjusting each other as covariates. We also investigated the differential effects of phthalate exposure on the intelligence and attention according to exposure period (maternal or children). Urine concentrations of mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-n-butyl phthalate (MBP) were analyzed. Multivariable linear regression models were used to investigate the relationship between exposure to various phthalates with IQ scores and continuous performance test (CPT) variables. There were robust associations between child MEHHP and MEOHP levels with full scale IQ (FSIQ) even after adjusting for demographic variables and CPT scores (MEHHP −9.27, 95% CI: −17.25, −1.29; MEOHP −9.83, 95% CI: −17.44, −2.21). Child MEHHP and MEHOP levels negatively affected omission errors (MEHHP −20.36, 95% CI: −34.17, −6.55; MEOHP −18.93, 95% CI: −32.58, −5.28) and the response time variability (MEHHP −21.07, 95% CI: −39.04, −3.10; MEOHP −20.41, 95% CI −38.14, −2.69) of the CPT after adjusting for demographic variables and IQ. Maternal phthalate exposure had no effects on IQ or CPT variables. These results suggest that children phthalate exposure, but not maternal exposure, has an adverse effect on IQ and attentional performance, and these associations were found to be independent of each other. [ABSTRACT FROM AUTHOR]

A fumigant toxicity tests were performed by using airtight plastic jars, in which five small glass tubes with perforated lids containing 20 cowpea seeds and four newly emerged Callosobruchus maculatus were placed. Filter paper impregnated with an appropriate volume (5, 10, 20, 40 µl/ml) of the oils were attached to the lower surface of the jar lid. Mortality counts were made at 6, 12, 24 and 48 h after treatment. For ovicidal activity, seeds having 20 eggs altogether were put in a glass vial and the treatments were followed as mentioned earlier. After 48 h of exposure the seeds with eggs were transferred and ovicidal activity was calculated based on the adult emergence. Among the essential oils tested, five oils, viz. camphor, eucalyptus, nutmeg and rosemary showed 100 % mortality even at lower dosages (5 µl) when adults were exposed for 48 h.Onthe other hand, seven oils showed 100% mortality at higher concentration (40 µl). Ovicidal activity revealed that 9 oils showed good activity against C. maculatus at higher concentrations. Among them four oils, viz. camphor, eucalyptus, rosemary and wintergreen showed 100 % egg mortality. In this work, it can be concluded that camphor, eucalyptus, nutmeg, rosemary, wintergreen oils showed very good fumigant and ovicidal activity. However, the possibility of utilising these plant oils to control C. maculatus in storage conditions may warrant further investigation. [ABSTRACT FROM AUTHOR]

Lantana camarais a common weed species in tropics and sub tropics and coastal locations of Asia. The fumigant toxicity of essential oil extracted from leaves of plant was tested against almond moth,Cadra cautella(Walker) (Lepidoptera, Phycitidae). Concentrations of essential oil relative to the wheat grains were 5, 10, 25, 50, 100 and 200 μl/l used against early eggs (0–24 hrs.), late eggs (2–3 days), early larvae (5–7 days), mid larvae (10–12days), late larvae (18–20 days) and early adult (0–24 hrs.) and late adults (2–3 days) stage ofC. cautella.The different concentrations of essential oil were applied to Whatman No. 1 with 2.5 cm in diameter filter paper and then pasted on the inner surface of the lid with adhesive tape in the bottom of fumigation flask ten eggs, larvae and adults of different ages with 20 wheat seeds were kept before keeping the treated filter paper, the lid was closed and sealed to create airtight condition in the chamber. The concentrations of essential oil were tested against different stages of test insect and one control with insect and wheat grain but without essential oil was maintained. The experiment was repeated thrice and observation was made at 6, 12, 24 and 48 hrs. of exposure period. Early eggs showed lower LC50value of 48.56 μl/L compared to 77.75 μl/L with late eggs. The larval LC50values ranged between 29–39 μl/L. Susceptibility of adult stage was also increased and the LC50values being 15.23 and 11.21 μl/L for early and late adult stages, respectively. [ABSTRACT FROM PUBLISHER]

This study on the population dynamics of fouling diatoms from a biofouling rich monsoon influenced tropical bay revealed that irrespective of the season and exposure period, the highest diatom abundance and species were encountered on non-toxic (fiberglass > glass) compared to toxic (copper–Cu and cupro-nickel–Cu-Ni) substrata. Though the diatom recruitment on toxic substrata is noticed within 24 h, the multiplication of the settled diatoms was not significant, even with an increase in the exposure period (days to weeks). The diatoms recorded on toxic substrata are the result of fresh recruitment. Results indicated that the potential of Cu and Cu–Ni panels to resist diatom fouling are the same. The dominance of raphid-pennate diatoms ( Navicula , Amphora , Nitzschia and Thalassionema ) throughout the year indicated them as ideal candidates for antifouling studies. The negligible contribution of araphid-pennate diatoms ( Licmophora and Grammatophora ) and the influence of tycho-pelagic/bloom forming diatoms ( Fragillariopsis and Skeletonema ) on fouling community are the other noteworthy observations. Concern with the adverse impact of Cu pollution on the ecosystem this study recommends the incorporation of Cu alloy (Cu–Ni) in the marine structures to combat biofouling as Cu–Ni has a slower leaching rate of the toxic product such as Cu 2 O. [ABSTRACT FROM AUTHOR]

Some vegetable seeds need a very long time to germinate. In these kinds of seeds the second phase of germination is very long. As acetylene's chemical structure is almost similar to the gaseous hormone ethylene, its' physiological effect on seed germination should be very similar as well. Therefore, an experiment was established in order to enhance seed germination, by treating seeds with acetylene released from interaction of calcium carbide (CaC2) with water (H2O). A simple system was designed for efficient and proper use of gaseous acetylene resulted from the two substrates interaction, which conducted the produced gas obtained inside the interaction chamber into a sealed container wherein seeds were floating in water. This experiment aimed to evaluate the effect of one concentration of acetylene with different exposure periods (between 1 to 8 hours) on parsley, celery and Swees chard seeds' germination (chosen as late germinating vegetables). The effect of acetylene on seed germination speed and percent was investigated. There were significant differences in both percent and speed of germination within the various treatments. By floating for 3, 5 and 3 hours for parsley, celery and Swiss chard respectively, the highest germination rates were observed. The highest germination speed was achieved by 5, 5 and 3 hours floating respectively for parsley, celery and Swiss chard. Based on the results obtained, the current experiment suggests that acetylene has positive effect on enhancing seed germination of named vegetables, and played the role of ethylene, its effects resembling in regard to seed germination process. [ABSTRACT FROM AUTHOR]

The quality of the biological activity data is of great importance for the development of algal quantitative structure–activity relationship (QSAR) models. However, a number of algal QSAR models in the literature were developed based on toxicity data without considering the response endpoints, exposure periods and species sensitivity. In this paper, 2323 algal toxicity data (log 1/EC 50 ) in different toxicity response endpoints for 1081 compounds to 26 algal species within different exposure periods (14 and 15 min; 24, 48, 72, 96, 168 and 192 h) were used to evaluate the quality of the toxicity data to green algae. Analysis of 72 h toxicity to algae showed that the closed test had the same sensitivity as the open test for most of the test compounds, but a significant difference was observed for a few compounds. The overall average difference for all compounds ranges from 0.15 to 0.43 log units between toxicity endpoints (yield–growth rate). The relationships between exposure periods of 24, 48, 72 and 96 h indicated that 48 h exposure period is the most sensitive for algal growth inhibition test, and its sensitivity is 0.25 log units greater than 72 and 96 h exposure periods, respectively. Interspecies relationships showed that some algal species have very close sensitivity (e.g. Pseudokirchneriella subcapitata and Chlorella pyrenoidosa or Chlorella vulgaris and Scenedesmus obliquus , respectively), whereas some species have significantly different sensitivity (e.g. P. subcapitata and S. obliquus ). Relationships between toxicity and hydrophobicity demonstrated that no difference was observed for non-polar narcotics within different exposure periods (24, 48, 72, and 96 h) or response variables (yield and growth rate). For polar narcotics, in contrast, algal toxicity is dependent on algal species and is related to the response variables and exposure period. We cannot expect significant QSAR models between algal toxicity and descriptors without considering species sensitivity, exposure periods and response endpoints. [ABSTRACT FROM AUTHOR]

A growing body of literature reports associations between exposure to particulate matter with diameter ≤2.5 μm (PM 2.5) during pregnancy and birth outcomes. However, findings are inconsistent across studies. To assess the association between PM 2.5 and birth outcomes of fetal growth in a cohort with high prevalence of siblings by multilevel models accounting for geographical- and mother-level correlations. In Israel, we used Maccabi Healthcare Services data to establish a population-based cohort of 381,265 singleton births reaching 24–42 weeks' gestation and birth weight of 500–5000 g (2004–2015). Daily PM 2.5 predictions from a satellite-based spatiotemporal model were linked to the date of birth and maternal residence. We generated mean PM 2.5 values for the entire pregnancy and for exposure periods during pregnancy. Associations between exposure and birth outcomes were modeled by using multilevel logistic regression with random effects for maternal locality of residence, administrative census area (ACA) and mother. In fully adjusted models with a mother-level random intercept only, a 10-μg/m3 increase in PM 2.5 over the entire pregnancy was positively associated with term low birth weight (TLBW) (Odds ratio, OR = 1.25, 95% confidence interval, CI: 1.09,1.43) and small for gestational age (SGA) (OR = 1.15, 95% CI: 1.06,1.26). Locality- and ACA-level effects accounted for <0.4% of the variance while mother-level effects explained ∼50% of the variability. Associations varied by exposure period, infants' sex, birth order, and maternal pre-pregnancy BMI. Consideration of mother-level variability in a region with high fertility rates provides new insights on the strength of associations between PM 2.5 and birth outcomes. • New evidence from the Middle East – a region with scarce data. • Maternal exposure to PM2.5 was associated with fetal growth outcomes. • Associations were clearer when mother-level clustering in the data was accounted for. • Associations were modified by infant's sex, birth order and maternal pre-pregnancy BMI. • Associations were highest for low socio-economic status and for third trimester of pregnancy. [ABSTRACT FROM AUTHOR]

• Systematic investigation of degraded semi-aromatic polyamine-based membrane by strong acids. • Degradation behavior of membrane to varying exposure periods was investigated • Morphology/Spectroscopy properties changed distinctly after exposure period of 150 days. • Hydrolysis and oxidative degradation effect caused by the acid solutions was explained. • Membrane degradation was severe in H 2 SO 4 than HCl degraded membranes. Rapid degradation of the active layer of nanofiltration (NF) membranes by acids contained in water and wastewater during industrial processes, needs to be understood to develop acid-resistant membranes with prolonged stability and durability. This study focuses on the degradation impact of a typical semi-aromatic polyamine-based NF membrane excited by two mineral acids (HCl and H 2 SO 4) having pH ≤ 0. Selected analytical tools were systematically engaged to investigate the morphological change, chemical composition, hydrophilicity and surface charge of the degraded membrane at varying and elongated exposure periods up to 150 days. The neat membrane was examined for comparison and the reaction mechanism between individual acid and the degraded membrane active layer was also studied. At early exposure periods of 7, 15 and 30 days, corresponding deterioration changes were noticed in both the HCl and H 2 SO 4 degraded membranes. However, at extended exposure periods of 90 and 150 days, the impact of degradation was more severe on the H 2 SO 4 degraded membrane as revealed by the SEM and XPS analyses. This was envisaged to be triggered by the prolonged dissociation of the acid which gradually weakens the bonds and the polymer structures, hence making it more vulnerable to further degradation. HCl and H 2 SO 4 readily dissociate to form hydrogen ions; a condition that favors the acid-catalyzed hydrolysis reaction pathway of the degraded membranes. This study thus serves as a reference to the expected behavioral change of semi-aromatic polyamine-based NF membrane used in acidic wastewater treatment and reclamation for extended periods. [ABSTRACT FROM AUTHOR]

Banana is a year round fruit in Bangladesh. After harvesting, banana is attacked by postharvest disease caused by some fungi. The quality and quantity losses of banana occur due to disease attacks and lack of proper postharvest handling. Fungus can be destroyed or made inactive by chemical or heat treatment. Most of the chemicals are hazardous to human health. Heat treatment technology is simple and is a non-chemical method to kill or inactivate pest and to control fungus. A hot water treatment plant was designed and developed with local materials for treating banana fruits. Overall dimensions of the hot water treatment plant were 1600 mmx926 mmx1566 mm and operated by an electrical motor of 0.38 kW. Water was heated by the six electric immersion heaters of 2,000 W of each. The capacity of the plant was 350 kg h-1. The price of the hot-water treatment plant was Taka 1,00,000 (US$ 1300) and treatment cost was Taka 0.55 kg ($0.007). The effective combinations of temperatures and exposure periods of BARI Kola 1 and Sabri Kola were found to be 55°C for 5 min. When the banana fruits were treated with hot water, the shelf-life of the fruits was found to increase by 30% and the postharvest loss reduced by 70% over those of untreated bananas. The break-even point of the plant was 70 h-1 yr. Banana fruits treated by the plant can be profitable to traders when the annual use of the plant exceeds 70 h-1. Payback period of the plant was estimated to be 26 d. Therefore, there is a good opportunity of farmers and traders to increase income and generate employment using the hot water treatment plant. [ABSTRACT FROM AUTHOR]

The effect of mixture of seeds of Brachiaria brizantha, cv. Marandu, with different sources, granulometry, and phosphatic fertilizer doses during various periods of exposure on the physiological potential of the seeds has been assessed. The treatments consisted in seed exposure during periods of 0, 3, 6, 12, 24, 36, 48, 72, 96, and 120 h to the following fertilizers: ground granulated single superphosphate (SS), and powdered (SSp); and ground granulated ammonium monophosphate (AMP), at doses of 40 and 80 kg P2O5 ha-1. Tests of germination, tetrazolium, moisture content, and vigor (first count, electrical conductivity, emergence, emergence speed, and fresh mass of seedlings) were performed. It has been concluded that seed physiological potential of B. brizantha cv. Marandu is reduced with increase on the exposure period to phosphatic fertilizer. Such effect, however, is dependent on the product source, granulometry, and dose. SSp was the most harmful to seeds, followed by SSp and AMP, respectively. Moreover, considering a 60% germination rate as acceptable, it may be inferred that seeds can be kept in contact with AMP and SSp, in dose of 80 kg of P2O5 ha-1, respectively, for periods of 71.2 and 16.2 hours. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of microwave radiation on Callosobruchus maculatus (Fabr., 1775) pupae in the cowpea (Vigna unguiculata) cultivars BRS Paraguaçu and BRS Xique-xique. The irradiation was made using a commercial microwave oven with a 2450 MHz frequency, 800 W power output, in low power (30%), with exposure periods to microwave radiation of 0, 60, 90, 120 and 150 seconds. It was observed, for both cultivars, reduction of the number of insects emerged per grain, number of insects emerged per treatment and increase in the egg to adult period, with 60 seconds exposure to microwave radiation. The 90, 120 and 150 seconds exposure periods to microwave radiation were lethal to 100% of the C. maculatus pupae. [ABSTRACT FROM AUTHOR]

The present work was designed to analyze cadmium (Cd) accumulation in Pisum sativum L. plants in a late stage of development, after an exposure to environmentally relevant Cd concentrations of 1, 3, and 30 μ mol L- 1 Cd. Cadmium exposure increased metal and thiol accumulation, not only in roots but also in the aerial organs of the plants. Nonetheless, except for the highest Cd exposure, plants did not show any evidence of Cd toxicity symptoms. Roots were found to be the main organs for Cd accumulation, but seeds also retained Cd, accumulating up to 2 μ g Cd g fw- 1. The parameters related to reproduction, such as anthesis and fruit development, were more sensitive to incipient degrees of stress than the biomass gain itself. When compared to previous works using hydroponic cultures, our results evidenced striking differences in Cd and thiol accumulation, suggesting the importance of using more realistic conditions in Cd-stress studies. The analysis of Cd retention in fruits demonstrated that, even at the lower exposure, Cd levels were higher than those allowed for human consumption, hence posing a serious risk of food-chain transfer and confirming the need for more studies on Cd accumulation in contaminated soils. [ABSTRACT FROM AUTHOR]

Abstract: Trichogramma dendrolimi can be successfully reproduced in fresh eggs dissected from ovaries of the Chinese tussah silkworm (Antheraea pernyi) and is widely used in biological control of lepidopteran agricultural and forest pests in China. Diapause induction of T. dendrolimi in A. pernyi eggs was investigated through exposing the parasitoid to six constant temperatures (16, 13, 10, 7, 4, and 1°C) for 19 exposure periods between 10 and 46days. The sensitive age of T. dendrolimi for diapause induction was explored through a separate experiment to examine the parasitoids that had developed for 2, 3, 4, 5, 6, 7, and 8days at 26°C after parasitization, under the six constant temperatures, respectively. Diapause was induced at 10 or 7°C, and the induction period was 4–6weeks. The sensitive age of T. dendrolimi to react at the induction temperature was 2–3days (at 26°C). At 7 and 10°C, the diapause rate increased with increasing exposure period and decreased with increased T. dendrolimi age at exposure. The optimum method to induce diapause in T. dendrolimi consisted of exposing hosts for parasitization at 26°C for 8h, and then keeping them at 26°C for 40h, finally, moving them into 10°C for 4weeks. [Copyright &y& Elsevier]

Abstract Background: The carcinogenesis of benzidine (BZ) and beta-naphthylamine (BNA) for bladder is well known. Although it was thought to be rare to develop occupational bladder cancer more than 20 years after the exposure to these chemicals, there are still new clinical cases even 30 years after exposure. The purpose of this study was to re-evaluate the latent carcinogenic period of BZ and BNA, in order to set the safety period after exposure for the health surveillance system. Methods: The subjects were 236 dyestuff-plant workers in Tokyo, who had been exposed to these dyestuffs. The incidence of bladder cancer and its histopathology in this group was surveyed in the period from 1962 to 1996. Results: Nineteen workers (8.1%) were found to have bladder cancers. The exposure period for these 19 patients was 82.0 ± 50.2 months. The mean ± SD latent period from the subjects’ initial and final exposure until tumor development was 29.5 ± 8.2 years and 20.1 ± 10.6 years, respectively. Significantly, a negative correlation (Pearson) was observed between the exposure period and the latent period from the end of exposure to cancer onset (R = –0.544, P < 0.05). All tumors except one were transitional cell carcinoma. Flow cytometric analysis was performed in 11 patients and all of these patients had DNA aneuploidy. Conclusions: The latent periods of bladder cancer caused by BZ and BNA were longer than previously expected. It is necessary to survey the onset of bladder cancer in exposed workers more than 30 years after the initial exposure. [ABSTRACT FROM AUTHOR]