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Knols Bart GJ
2004-12-01
Full Text Available Abstract Background Anopheles gambiae Giles is the most important vector of human malaria in sub-Saharan Africa. Knowledge of the factors that influence its daily oviposition pattern is crucial if field interventions targeting gravid females are to be successful. This laboratory study investigated the effect of oviposition substrate and time of blood feeding on daily oviposition patterns of An. gambiae mosquitoes. Methods Greenhouse-reared gravid and hypergravid (delayed oviposition onset An. gambiae sensu stricto and wild-caught An. gambiae sensu lato were exposed to three types of substrates in choice and no-choice cage bioassays: water from a predominantly anopheline colonised ground pool (anopheline habitat water, swamp water mainly colonised by culicine larvae (culicine habitat water and distilled water. The daily oviposition pattern and the number of eggs oviposited on each substrate during the entire egg-laying period were determined. The results were subjected to analysis of variance using the General Linear Model (GLM procedure. Results The main oviposition time for greenhouse-reared An. gambiae s.s. was between 19:00 and 20:00 hrs, approximately one hour after sunset. Wild-caught gravid An. gambiae s.l. displayed two distinct peak oviposition times between 19:00 and 20:00 hrs and between 22:00 and 23:00 hrs, respectively. During these times, both greenhouse-reared and wild-caught mosquitoes significantly (P P Conclusion This study shows that the peak oviposition time of An. gambiae s.l. may be regulated by the light-dark cycle rather than oviposition habitat characteristics or feeding times. However, the number of eggs laid by the female mosquito during the peak oviposition time is affected by the suitability of the habitat.
Spatial patterns of high Aedes aegypti oviposition activity in northwestern Argentina.
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Elizabet Lilia Estallo
Full Text Available BACKGROUND: In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. METHODOLOGY: Oviposition activity was detected in Orán City (Salta province using ovitraps, weekly replaced (October 2005-2007. Spatial autocorrelation was measured with Moran's Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. PRINCIPAL FINDINGS: Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC=0.77, obtaining 99% of sensitivity and 75.29% of specificity. CONCLUSIONS: Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist
de Farias-Martins, Fernando; Sperber, Carlos Frankl; Albeny-Simões, Daniel; Breaux, Jennifer Ann; Fianco, Marcos; Szinwelski, Neucir
2017-01-01
For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.
Laboratory and field evaluation of an oviposition trap for Culex quinquefasciatus(Diptera: Culicidae
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Rosângela MR Barbosa
2007-06-01
Full Text Available An ovitrap (BR-OVT based on physical and chemical stimuli for attracting gravid Culex quinquefasciatus (Diptera: Culicidae females was developed and evaluated under laboratory and field conditions. Attractants were assayed using alternative chamber bioassays prior to being used in the BR-OVT oviposition trap. A significant preference of gravid females for sites containing conspecific egg rafts was observed, as a response to the natural oviposition pheromone, as well as for sites treated with the synthetic pheromone erythro-6-acetoxy-5-hexadecanolide. Five- to 20-day old grass infusion was strongly attractive to gravid females for laying eggs. On the other hand, entomopathogenic Bacillus sphaericus (Bs did not influence the choice of an oviposition site when used in combination with grass infusion and can therefore be used as a larvicide in ovitraps. Results from field trials showed that the BR-OVT with grass infusion and with or without Bs works as a preferred oviposition site for Cx. quinquefasciatus. The BR-OVT was more effective for egg collection when placed indoors and comparison with the number of egg rafts laid in cesspits over 40 days indicates that this very simple ovitrap may be a useful tool for monitoring populations of the most important of the vectors of bancroftian filariasis.
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Micieli María Victoria
2003-01-01
Full Text Available Monthly oviposition activity and the seasonal density pattern of Aedes aegypti were studied using larvitraps and ovitraps during a research carried out by the Public Health Ministry of Salta Province, in Tartagal, Aguaray and Salvador Mazza cities, in subtropical Argentina. The A. aegypti population was active in both dry and wet seasons with a peak in March, accordant with the heaviest rainfall. From May to November, the immature population level remained low, but increased in December. Ae. aegypti oviposition activity increased during the fall and summer, when the relative humidity was 60% or higher. Eggs were found in large numbers of ovitraps during all seasons but few eggs were observed in each one during winter. The occurrence and the number of eggs laid were variable when both seasons and cities were compared. The reduction of the population during the winter months was related to the low in the relative humidity of the atmosphere. Significant differences were detected between oviposition occurrences in Tartagal and Aguaray and Salvador Mazza cities, but no differences in the number of eggs were observed. Two factors characterize the seasonal distribution pattern of Ae. aegypti in subtropical Argentina, the absence of a break during winter and an oviposition activity concomitant of the high relative humidity of the atmosphere.
Rhagoletis cerasi: Oviposition Reduction Effects of Oil Products
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Claudia Daniel
2014-04-01
Full Text Available The European cherry fruit fly, Rhagoletis cerasi (L. (Diptera: Tephritidae, is a highly destructive pest. Methods to control it are limited and alternatives are needed. Observations of cherry fruit flies suggest that females exert much effort to penetrate cherries at color change stage (from green to yellow for oviposition. Therefore, the question arose as to whether a physical barrier on the fruit surface could reduce oviposition. The effects of different commercial horticultural oil products on R. cerasi oviposition were evaluated in a series of laboratory, semi-field and field experiments. In the laboratory experiments, the rate of successful oviposition on fruits treated with 0.25% v/v of the rapeseed oil product Telmion was significantly reduced by 90% compared to the untreated control. In semi-field experiments, deposits of 1% of rapeseed, mineral and paraffinic oil significantly reduced oviposition for up to 3 days. Semi-field experiments indicated that the oil products lose efficacy within 3 to 6 days after application due to degradation. Although treatments with the rapeseed oil product Telmion reduced infestation rates in an on-farm field experiment, the infested fruit clearly exceeded the level of market tolerance of 2%. Further research is needed to assess whether combinations of oil products, higher application rates and different formulations might improve field efficacy.
Oviposition of aquatic insects in a tropical high altitude stream.
Rios-Touma, Blanca; Encalada, A C; Prat, N
2012-12-01
The persistence of aquatic insect populations in streams depends on the recruitment of larval populations from egg masses deposited by adults, especially after disturbance. However, recruitment of aquatic populations by oviposition is a process that remains unstudied in streams and rivers. The objectives of our study were to document flying and oviposition patterns of aquatic insects in a high altitude tropical stream during both dry and wet seasons. In particular we studied 1) richness and abundance of adult forms of aquatic insects flying and ovipositing; 2) number of eggs (oviposition pattern), egg mass identity, and morphology; and 3) substrate preferences by ovipositing females. We found 2,383 aquatic insects corresponding to 28 families, with dipterans representing 89% of total individuals collected. Adult insects had lower richness (28 taxa) than larval diversity (up to 52 taxa) and distinct community composition. Richness and relative abundance of most taxa (adults) were not significantly different between seasons, behaviors, diel period, or all three. During both sampling periods we found females with eggs in a total of 15 different families (13 in the dry season and 14 in the wet season). There were no significant differences in the proportion of females with eggs between seasons, diel periods, or different behaviors (flying versus ovipositing traps) of the different female taxa. Few types of egg masses were found in rocks at the stream during both seasons, and most egg masses found corresponded to families Baetidae and Chironomidae. Finally, we provide the first description of eggs masses (size, shape, color, and number of eggs per female) of gravid females (10 taxa) and those found in the stream substrate (six taxa) of Andean macroinvertebrates. This is the first study reporting oviposition, adult diversity, and oviposition patterns of aquatic insects in the Andean region.
Species Abundance and Colour Preferences of Oviposition by ...
African Journals Online (AJOL)
A study was conducted to determine the occurrence and colour preferences of oviposition by mosquitoes in man-made containers under field conditions. A total of nine (9) different colour 2 litre plastic containers were used as artificial mosquito oviposition containers. They were filled with equal amounts of water and placed ...
Al-Wahaibi, Ali K; Morse, Joseph G
2010-02-01
A detailed study of the distribution of egg masses of Homalodisca vitripennis (Germar) and H. liturata Ball was done across a 2-yr period (2001-2003) on six host plants in southern California (Marsh grapefruit, Lisbon lemon, Washington navel, Dancy tangerine, rough lemon, and jojoba in Riverside; jojoba in Desert Center). The majority of egg masses in Riverside belonged to H. vitripennis (84-100%), whereas in Desert Center, all Homalodisca egg masses were H. liturata. Oviposition in Riverside occurred in two discrete periods, a late winter and spring period (mid-February to late May), followed by a short interval of very low oviposition during most of June, and then a summer period (late June to late September) followed by a relatively long period of very low oviposition in fall and early winter (October to mid-February). Levels of oviposition during the late winter-spring period were similar to those during the summer despite an observed larger population of adults during the latter period. Moreover, egg clutch size for H. vitripennis was generally greater in spring than during summer and was generally higher than that for H. liturata, especially on Riverside jojoba. Larger egg clutch size was seen on grapefruit than on lemon, navel, and tangerine during summer. There appeared to be temporal host shifts in oviposition; most evident was the shift from relatively high rates of oviposition on lemon and tangerine in late winter-early spring to relatively higher rates of oviposition on grapefruit and navel during summer.
Thomas, J A; Elmes, G W
2001-03-07
It has been suggested that the socially parasitic butterfly Maculinea alcon detects ant odours before ovipositing on initial larval food plants near colonies of its obligate ant host Myrmica ruginodis. It has also been suggested that overcrowding on food plants near M. ruginodis is avoided by an ability to detect high egg loads, resulting in a switch to selecting plants near less suitable ant species. If confirmed, this hypothesis (H1) would have serious implications for the application of current population models aimed at the conservation of endangered Maculinea species, which are based on the null hypothesis (H0) that females randomly select food plants whose flower buds are at a precise phenological stage, making oviposition independent of ants. If H1 were wrong, practical management based upon its assumptions could lead to the extinction of protected populations. We present data for the five European species of Maculinea which show that (i) each oviposits on a phenologically restricted flower-bud stage, which accounts for the apparent host-ant-mediated niche separation in sympatric populations of Maculinea nausithous and Maculinea teleius, (ii) there is no temporal shift in oviposition by Maculinea arion in relation to host ant distribution or egg density, and (iii) oviposition patterns in 13 populations of M. alcon's closest relative, Macaulinea rebeli, conform to H0 not H1 predictions. It is concluded that conservation measures should continue to be based on H0.
Sasakawa, Kôji; Uchijima, Kenta; Shibao, Harunobu; Shimada, Masakazu
2013-02-01
Many parasitoid wasps learn host-associated cues and use them in subsequent host-searching behavior. This associative learning, namely "oviposition learning," has been investigated in many studies. However, few studies have compared multiple species, and no comparative study has previously been conducted on ectoparasitoid species. We compared the effects of oviposition learning on host preference and offspring sex ratio in two closely related ectoparasitoid wasps with contrasting reproductive strategies, Anisopteromalus calandrae (r-strategist) and its sibling species (K-strategist). Using two bruchine hosts, Callosobruchus chinensis and Callosobruchus maculatus larvae infesting the cowpea Vigna unguiculata, oviposition choice experiments were performed at high and low host densities. In both species, no conspicuous effect on the offspring sex ratio was detected, but effects on host preference were found to differ between the species. In A. calandrae, the effects were detected only at high host density, suggesting that oviposition learning plays a role in host discrimination from a short distance but not from a long distance. In the sibling species, those effects were not detected in any of the cases, suggesting the absence of oviposition learning. These results are compatible with those of previous comparative studies of endoparasitoid wasps in that few lifetime oviposition experiences and/or low reward per foraging decision result in low or absent oviposition learning ability. This finding may indicate that ecological traits contributing to learning ability are similar between endoparasitoid and ectoparasitoid wasps. Thus, our species comparison of ectoparasitoids provides another model system for investigating learning and memory dynamics in parasitoid wasps.
Quasi-double-blind screening of semiochemicals for reducing navel orangeworm oviposition on almonds.
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Kevin Cloonan
Full Text Available A three-step, quasi-double-bind approach was used as a proof-of-concept study to screen twenty compounds for their ability to reduce oviposition of gravid female navel orangeworm(NOW, Ameylois transitella (Lepidoptera: Pyralidae. First, the panel of compounds, whose identity was unknown to the experimenters, was tested by electroantennogram (EAG using antennae of two-day old gravid females as the sensing element. Of the twenty compounds tested three showed significant EAG responses. These three EAG-active compounds and a negative control were then analyzed for their ability to reduce oviposition via small-cage, two-choice laboratory assays. Two of the three compounds significantly reduced oviposition under laboratory conditions. Lastly, these two compounds were deployed in a field setting in an organic almond orchard in Arbuckle, CA using black egg traps to monitor NOW oviposition. One of these two compounds significantly reduced oviposition on black egg traps under these field conditions. Compound 9 (later identified as isophorone showed a significant reduction in oviposition in field assays and thus has a potential as a tool to control the navel orangeworm as a pest of almonds.
International Nuclear Information System (INIS)
Alama, D.
1999-01-01
The current work was conducted in order to determine the level of oviposition of Anastrepha fraterculus on fresh mangos and artificial oviposition devices. Four trials were carried out during which freshly harvested fruit was exposed to wild South American adult fruit flies. The following viable oviposition/day/kg of fruit (viable ovipositions = emerged adults) were established: 79.16, 71.25, 83.6 and 60.6. The trials were carried out at 25 deg. C - 28 deg. C and 60%-80% relative humidity. Beginning with the first generation one trial was carried out which confirmed the acceptance of sexually mature females to oviposit on red oviposition devices consisting of wax-covered cloth. However, red plastic containers with holes of 0.5 mm did not produce good results. (author)
Chadee, D D
2012-11-01
The blood-feeding behaviour of the Trinidad strain of Aedes aegypti was studied, under laboratory conditions, using one female per cage and monitoring blood feeding immediately, 12, and 24 hours after oviposition. To get large numbers of females that had newly completed their first gonotrophic cycle, the diel oviposition periodicity was conducted using single females per cage and monitoring at 2-hour intervals. The diel oviposition periodicity showed a small morning peak (8%) during the first 2 hours of the photophase after which oviposition declined: during the second half of the photophase, oviposition increased reaching a peak comprising 56% of eggs (G = 59·9, P>0·01) between 16:00 and 18:00 hours. At post-oviposition hour 0, only five (10%) of the females accepted a blood meal but at post-oviposition hour 12, significantly more (G = 46·98, P>0·02) females, 35 (70%) accepted a blood meal. This pattern was consistently observed when females were offered blood meals at 12 and 24 hours after completing their first gonotrophic cycle. Multiple feeding was observed among the blood-feeding females and the results of this study are discussed in the context of disease transmission patterns and physiological mechanisms which control their blood-feeding behaviours.
Construction of a field trap for initiating an ovipositional response in Aedes taeniorhynchus.
Wallace, F L
1996-09-01
An oviposition trap was constructed for the black saltmarsh mosquito, Aedes taeniorhynchus. The trap consisted of a 50 x 60-cm piece of contaminated 100% cotton bath towel, saturated with 85% tap water, a container, and a cover of dried plant parts placed over the contaminated toweling. This combination initiated oviposition. Contamination of the toweling was due to populations of bacteria and fungi. The eggs recovered were free from soil and debris.
Ody, Helen; Bulling, Mark T; Barnes, Kate M
2017-06-01
A number of factors are known to affect blow fly behavior with respect to oviposition. Current research indicates that temperature is the most significant factor. However temperature thresholds for oviposition in forensically important blow flies have not been well studied. Here, the oviposition behavior of three species of forensically important blow fly species (Calliphora vicina, Calliphora vomitoria and Lucilia sericata,) was studied under controlled laboratory conditions over a range of temperatures (10-40°C). Lower temperature thresholds for oviposition of 16°C and 17.5°C were established for C. vomitoria and L. sericata respectively, whilst C. vicina continued to lay eggs at 10°C. C. vomitoria and L. sericata both continued to lay eggs at 40°C, whilst the highest temperature at which oviposition occurred in C. vicina was 35°C. Within these thresholds there was considerable variation in the number of surviving pupae, with a general pattern of a single peak within the range of temperatures at which eggs were laid, but with the pattern being much less distinct for L. sericata. Copyright © 2017 Elsevier B.V. All rights reserved.
Mediterranean fruit fly: interference of oviposition by radiation-sterilized females in field cages
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McInnis, D. O. [Tropical Fruit and Vegetable Research Lab. USDA-ARS, Honolulu, HI (United States); Wong, T. T.Y.
1990-07-01
In experiments between April and September 1984, the behaviour of nonirradiated and radiation-sterilized laboratory-adapted adults of the tephritid Ceratitis capitata was observed on apples hung on guava trees in outdoor cages in Hawaii. The numbers of nonirradiated females observed resting on fruit were reduced several times by the presence of irradiated females, either alone or with irradiated males, but not by irradiated males alone. Similarly, the number of nonirradiated females observed ovipositing and the duration of oviposition was reduced by the presence of irradiated females. In control cages (all nonirradiated flies), the duration of oviposition by females averaged 255.9±15.0 s on fruit, while most of nonirradiated and irradiated females in the mixed (treatment) cage averaged 157±19.8 s and 77.5±7.5 s on fruit, resp. Irradiated females behaved skittishly on fruit and frequently engaged in physical encounters with other flies.
Harrington, L C; Ponlawat, A; Edman, J D; Scott, T W; Vermeylen, F
2008-06-01
We conducted a study to determine the effect of container size and location on oviposition site selection by Ae. aegypti in large outdoor field enclosures (10 x 10 x 4 m high). There was a strong positive relationship between increasing container diameter, container volume, and water surface area with egg numbers over both high (rainy, July) and low (cool-dry, January) dengue transmission seasons. Location of containers (indoors versus immediately outdoors and underneath houses) did not influence the number of eggs deposited for containers 5-32 cm in diameter in either season. No trends based on container color (black, brown, or grey) were observed. A slight trend with a greater numbers of eggs laid outdoors in the largest containers (42 cm diameter) during the dry season was observed. Three separate models were run using the mixed model procedure in SAS for each container attribute. Controlling for season, time, and date, the most important container attribute predicting total egg numbers was container volume (total capacity) explaining 88% of the variation, followed by water surface area (85%), and container diameter opening (83%). Oviposition peaked in the afternoon at 1600 hrs and 2000 hrs in the dry and rainy seasons, respectively. Few eggs were laid overnight (2000 hrs-0600 hrs). Our results indicate that physical attributes of oviposition sites, such as size, light-dark contrasts, and specular reflectance from water surfaces, play a significant role in oviposition site selection.
The role of cow urine in the oviposition site preference of culicine and Anopheles mosquitoes
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Kweka Eliningaya J
2011-09-01
Full Text Available Abstract Background Chemical and behavioural ecology of mosquitoes plays an important role in the development of chemical cue based vector control. To date, studies available have focused on evaluating mosquito attractants and repellents of synthetic and human origins. This study, however, was aimed at seasonal evaluation of the efficiency of cow urine in producing oviposition cues to Anopheles gambiae s.l. and Culex quinquefasciatus in both laboratory and field conditions. Methods Oviposition response evaluation in laboratory conditions was carried out in mosquito rearing cages. The oviposition substrates were located in parallel or in diagonal positions inside the cage. Urine evaluation against gravid females of An. arabiensis and Cx. quinquefasciatus was carried out at Day 1, Day 3 and Day 7. Five millilitres (mls of cow urine was added to oviposition substrate while de-chlorinated water was used as a control. In field experiments, 500 mls of cow urine was added in artificial habitats with 2500 mls of de-chlorinated water and 2 kgs of soil. The experiment was monitored for thirty consecutive days, eggs were collected daily from the habitats at 7.00 hrs. Data analysis was performed using parametric and non-parametric tests for treatments and controls while attraction of the oviposition substrate in each species was presented using Oviposition Activity Index (OAI. Results The OAI was positive with ageing of cattle urine in culicine species in both laboratory and field experiments. The OAI for anopheline species was positive with fresh urine. The OAI during the rainy season was positive for all species tested while in the dry season the OAI for culicine spp and Anopheles gambiae s.l., changed with time from positive to negative values. Based on linear model analysis, seasons and treatments had a significant effect on the number of eggs laid in habitats, even though the number of days had no effect. Conclusion Oviposition substrates treated with
Periodical cicadas use light for oviposition site selection.
Yang, Louie H
2006-12-07
Organisms use incomplete information from local experience to assess the suitability of potential habitat sites over a wide range of spatial and temporal scales. Although ecologists have long recognized the importance of spatial scales in habitat selection, few studies have investigated the temporal scales of habitat selection. In particular, cues in the immediate environment may commonly provide indirect information about future habitat quality. In periodical cicadas (Magicicada spp.), oviposition site selection represents a very long-term habitat choice. Adult female cicadas insert eggs into tree branches during a few weeks in the summer of emergence, but their oviposition choices determine the underground habitats of root-feeding nymphs over the following 13 or 17 years. Here, field experiments are used to show that female cicadas use the local light environment of host trees during the summer of emergence to select long-term host trees. Light environments may also influence oviposition microsite selection within hosts, suggesting a potential behavioural mechanism for associating solar cues with host trees. In contrast, experimental nutrient enrichment of host trees did not influence cicada oviposition densities. These findings suggest that the light environments around host trees may provide a robust predictor of host tree quality in the near future. This habitat selection may influence the spatial distribution of several cicada-mediated ecological processes in eastern North American forests.
Host ant independent oviposition in the parasitic butterfly Maculinea alcon
DEFF Research Database (Denmark)
Fürst, Matthias A; Nash, David Richard
2010-01-01
to host-ant nests and non-host-ant nests, and the number and position of eggs attached were assessed. Our results show no evidence for host-ant-based oviposition in M. alcon, but support an oviposition strategy based on plant characteristics. This suggests that careful management of host-ant distribution......Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host......-ant-dependent oviposition in this and other Maculinea species have, however, shown equivocal results, leading to a long-term controversy over support for this hypothesis. We therefore conducted a controlled field experiment to study the egg-laying behaviour of M. alcon. Matched potted Gentiana plants were set out close...
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Catta-Preta Patrícia Diniz
2003-01-01
Full Text Available Host part selection by ovipositing females of Ascia monuste (Godart, 1919 (Lepidoptera, Pieridae on kale (Brassica oleracea var. acephala was determined in greenhouse and field. Performance of offspring (larval period, efficiency of food utilization, number of eggs/female and others was investigated under laboratory conditions. In the field, the number of A. monuste egg clutches on the apical and medium parts of kale leaves was greater than on the basal part. In greenhouse, A. monuste exhibited a strong preference for the apical part of kale leaves for ovipositing. The best results on food utilization indices, pupal mass and female wing size were obtained with the leaf apical part. This part of kale leaves exhibited the highest nitrogen and protein concentration and the smallest water content, when compared to the other leaf parts. However, the apical part of the leaves seems not to provide ovipositing females with enough protection against birds, making them easy preys in the field. We suggest that good relationship between oviposition preference and performance of offspring was hindered by predation in field conditions.
Mahat, N A; Zainol-Abidin, N L; Nordin, N H; Abdul-Wahab, R; Jayaprakash, P T
2016-03-01
Considering that crimes against animals such as illegal killing and cruelty have been alarmingly increasing and since burning is one of the common ways for disposing cadavers, ability to estimate minimum postmortem interval (PMI) using entomological data merits consideration. Chrysomya megacephala and Chrysomya rufifacies are common necrophagous species recovered from cadavers in many countries including Malaysia. Specific studies focusing on the oviposition and developmental patterns of both species on cadavers manifesting different levels of burn as described by the Crow-Glassman Scale (CGS) remain scarce. In four replicates, rabbit carcasses were burned to CGS levels #1, #2 and #3 by varying the amount of petrol used and duration of burning. Oviposition by C. megacephala and C. rufifacies was delayed by one day in the case of carcasses burned to the CGS level #3 (p0.05) in the duration of development were found between control and burned carcasses. These findings deserve consideration while estimating minimum PMI since burning as a mean for disposing animal and human cadavers is gaining popularity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Oviposition behaviour of Phlebotomus argentipes--a laboratory-based study.
Kumar, Vijay; Rama, Aarti; Kesari, Shreekant; Bhunia, Gouri Sankar; Dinesh, Diwakar Singh; Das, Pradeep
2013-12-01
The breeding habitat of sandflies is a little studied and poorly understood phenomenon. More importantly, oviposition behaviour is a largely neglected aspect of sandfly biology and this knowledge gap further undermines our understanding of the biology of sandflies. Pheromones released by the eggs play an important role in identifying good sites for oviposition by female insects. Several recent studies have examined the oviposition pheromone. The present study provides a preliminary report on the oviposition behaviour of Phlebotomus argentipes, the only vector of kala-azar (or visceral leishmaniasis) on the Indian sub-continent. Sandflies prefer to oviposit their eggs on surfaces that contain organic substances, especially substances with an odour of decaying animal products and the remains of conspecific eggs. The results presented here suggest that the odour released by the organic substances of old sandfly colony remains that contain dead flies, old unhatched eggs, larval food containing vertebrate faeces, frass and other organic matter serves as an attractant for the ovipositing females of P. argentipes and hence greatly increases the number of oviposited eggs compared to eggs deposited in controlled oviposition pots. This result will be helpful in maintaining an efficient colony of P. argentipes and may be a promising tool for monitoring and controlling the target insect as part of a synergistic approach.
Davis, Timothy J; Kline, Daniel L; Kaufman, Phillip E
2016-03-01
Aedes albopictus (Skuse) is a container-breeding mosquito commonly found in residential areas of its range in the United States. Mosquitoes are known to utilize flowering plants for sugar acquisition. Limited information is known about the influences on oviposition site selection, outside of container size. Residential areas are often landscaped with a variety of flowering plants and are known to provide numerous sizes of potential larval developmental sites for container-breeding mosqutioes. Through screened enclosure and field studies, the oviposition preference of Ae. albopictus for containers of three selected sizes (473, 946 and 1,892 ml) and the influence of flowering butterfly bush (Buddleja davidii Franchett cultivar 'Guinevere') plants were examined. Our results document that significantly more eggs were oviposited in the largest containers. Additionally, significantly more eggs were oviposited in containers adjacent to flowering butterfly bushes than in those without a flowering butterfly bush. Finally, our results document that flowering butterfly bushes exerted greater influence over Ae. albopictus oviposition decisions than did container size. Our findings can be applied to several aspects of Ae. albopictus surveillance and control.
The effects of oviposition-site deprivation on Anopheles gambiae reproduction
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Dieter Kathryne L
2012-10-01
Full Text Available Abstract Background The African malaria mosquito, Anopheles gambiae, depends on availability of suitable surface water for oviposition. Short and long dry spells occur throughout the year in many parts of its range that limit its access to oviposition sites. Although not well understood, oviposition-site deprivation has been found to rapidly reduce egg batch size and hatch rate of several mosquito species. We conducted laboratory experiments to assess these effects of oviposition-site deprivation on An. gambiae and to evaluate the role of nutrition and sperm viability as mediators of these effects. Methods Anopheles gambiae adults (1–2 d old from the G3 laboratory colony were assigned to the following treatment groups: oviposition-deprived (fed once and then deprived of oviposition site for 7 or 14 d, multiple-fed control (fed regularly once a week and allowed to lay eggs without delay, and age matched blood-deprived control (fed once, three days before water for oviposition was provided. Egg batch size and hatch rate were measured. In the second experiment two additional treatment groups were included: oviposition-deprived females that received either a second (supplemental blood meal or virgin males (supplemental mating 4 days prior to receiving water for oviposition. Results An. gambiae was highly sensitive to oviposition-site deprivation. Egg batch size dropped sharply to 0–3.5 egg/female within 14 days, due to reduced oviposition rate rather than a reduced number of eggs/batch. Egg hatch rate also fell dramatically to 0-2% within 7 days. The frequency of brown eggs that fail to tan was elevated. A supplemental blood meal, but not ‘supplemental insemination,’ recovered the oviposition rate of females subjected to oviposition-site deprivation. Similarly, a supplemental blood meal, but not ‘supplemental insemination,’ partly recovered hatch rate, but this increase was marginally significant (P Conclusions Even a short dry spell
Nocturnal Oviposition Behavior of Forensically Important Diptera in Central England.
Barnes, Kate M; Grace, Karon A; Bulling, Mark T
2015-11-01
Timing of oviposition on a corpse is a key factor in entomologically based minimum postmortem interval (mPMI) calculations. However, there is considerable variation in nocturnal oviposition behavior of blow flies reported in the research literature. This study investigated nocturnal oviposition in central England for the first time, over 25 trials from 2011 to 2013. Liver-baited traps were placed in an urban location during control (diurnal), and nocturnal periods and environmental conditions were recorded during each 5-h trial. No nocturnal activity or oviposition was observed during the course of the study indicating that nocturnal oviposition is highly unlikely in central England. © 2015 American Academy of Forensic Sciences.
Investigation of nocturnal oviposition by necrophilous flies in central Texas.
Baldridge, Robert S; Wallace, Susan G; Kirkpatrick, Ryan
2006-01-01
The need to accurately estimate the postmortem interval (PMI) has prompted research into factors affecting fly oviposition (i.e., oviposition and/or larviposition) on a corpse. Research efforts have focused on whether or not diurnally active flies oviposit during nighttime hours. This study reports that nocturnal oviposition (defined as occurring between 2100-0600 h CDST (Central Daylight Savings Time)) did not occur on freshly killed white rats or mice, on beef (fresh or aged up to 48 h), on freshly thawed pigs, nor, usually, on thawed pigs that were aged for up to 48 h. Limited oviposition did occur between 2100 and 2120 h on one bloated pig at a lighted rural site. Necrophilous flies were present and active at lighted and dark sites (urban and rural) before and immediately after sunset, but fly activity on the bait ceased within 50 min postsunset and did not resume until after 0600 h. These observations support other studies reporting that diurnally active flies do not oviposit during the nighttime.
Semiochemicals released by plant-microbe associations are used by herbivorous insects to access and evaluate food resources and oviposition sites. Adult insects may utilize microbial-derived nutrients to prolong their lifespan, promote egg development and offer a high nutritional substrate to their ...
Spatial variability in oviposition damage by periodical cicadas in a fragmented landscape.
Cook, William M; Holt, Robert D; Yao, Jin
2001-03-01
Effects of the periodical cicada (Magicicada spp.) on forest dynamics are poorly documented. A 1998 emergence of M. cassini in eastern Kansas led to colonization of a fragmented experimental landscape undergoing secondary succession. We hypothesized that per-tree rates of oviposition damage by cicadas would reflect: (1) distance from the source of the emergence, (2) patch size, and (3) local tree density. Ovipositing females displayed clear preferences for host species and damage incidence showed predictable spatial patterns. Two species (smooth sumac, Rhus glabra, and eastern red cedar, Juniperus virginiana) were rarely attacked, whereas others (rough-leaved dogwood, Cornus drummondii; slippery elm, Ulmus rubra; box elder, Acer negundo, and honey locust, Gleditsia triacanthos) were strongly attacked. The dominant early successional tree, dogwood, received on average the most attacks. As predicted, attacks per stem declined strongly with distance from the emergence source, and with local stem density (a "dilution" effect). Contrary to expectations, there were more attacks per stem on larger patches. Because ovipositing cicadas cut damaging slits in host tree branches, potentially affecting tree growth rate, competitive ability, and capacity to reproduce, cicada damage could potentially influence spatial variation in secondary succession.
Dieng, Hamady; Rahman, G. M. Saifur; Abu Hassan, A.; Che Salmah, M. R.; Satho, Tomomitsu; Miake, Fumio; Boots, Michael; Sazaly, Abubakar
2012-01-01
Larvae of Aedes albopictus Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall, Ae. albopictus may experience increased loss of immature stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of Ae. albopictus. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of Ae. albopictus and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
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Brian M Leckie
Full Text Available Acylsugars are secondary metabolites exuded from type IV glandular trichomes that provide broad-spectrum insect suppression for Solanum pennellii Correll, a wild relative of cultivated tomato. Acylsugars produced by different S. pennellii accessions vary by sugar moieties (glucose or sucrose and fatty acid side chains (lengths and branching patterns. Our objective was to determine which acylsugar compositions more effectively suppressed oviposition of the whitefly Bemisia tabaci (Gennadius (Middle East--Asia Minor 1 Group, tobacco thrips, Frankliniella fusca (Hinds, and western flower thrips, Frankliniella occidentalis (Pergande. We extracted and characterized acylsugars from four S. pennellii accessions with different compositions, as well as from an acylsugar-producing tomato breeding line. We also fractionated the acylsugars of one S. pennellii accession to examine the effects of its components. Effects of acylsugars on oviposition were evaluated by administering a range of doses to oviposition sites of adult whiteflies and thrips in non-choice and choice bioassays, respectively. The acylsugars from S. pennellii accessions and the tomato breeding line demonstrated differential functionality in their ability to alter the distribution of whitefly oviposition and suppress oviposition on acylsugar treated substrates. Tobacco thrips were sensitive to all compositions while western flower thrips and whiteflies were more sensitive to acylsugars from a subset of S. pennellii accessions. It follows that acylsugars could thus mediate plant-enemy interactions in such a way as to affect evolution of host specialization, resistance specificity, and potentially host differentiation or local adaptation. The acylsugars from S. pennellii LA1376 were separated by polarity into two fractions that differed sharply for their sugar moieties and fatty acid side chains. These fractions had different efficacies, with neither having activity approaching that of the
Wong, Jacklyn; Stoddard, Steven T.; Astete, Helvio; Morrison, Amy C.; Scott, Thomas W.
2011-01-01
Background Because no dengue vaccine or antiviral therapy is commercially available, controlling the primary mosquito vector, Aedes aegypti, is currently the only means to prevent dengue outbreaks. Traditional models of Ae. aegypti assume that population dynamics are regulated by density-dependent larval competition for food and little affected by oviposition behavior. Due to direct impacts on offspring survival and development, however, mosquito choice in oviposition site can have important consequences for population regulation that should be taken into account when designing vector control programs. Methodology/Principal Findings We examined oviposition patterns by Ae. aegypti among 591 naturally occurring containers and a set of experimental containers in Iquitos, Peru. Using larval starvation bioassays as an indirect measure of container food content, we assessed whether females select containers with the most food for their offspring. Our data indicate that choice of egg-laying site is influenced by conspecific larvae and pupae, container fill method, container size, lid, and sun exposure. Although larval food positively influenced oviposition, our results did not support the hypothesis that females act primarily to maximize food for larvae. Females were most strongly attracted to sites containing immature conspecifics, even when potential competitors for their progeny were present in abundance. Conclusion/Significance Due to strong conspecific attraction, egg-laying behavior may contribute more to regulating Ae. aegypti populations than previously thought. If highly infested containers are targeted for removal or larvicide application, females that would have preferentially oviposited in those sites may instead distribute their eggs among other suitable, previously unoccupied containers. Strategies that kill mosquitoes late in their development (i.e., insect growth regulators that kill pupae rather than larvae) will enhance vector control by creating
Mitchell, E R; Heath, R R
1985-05-01
Common pigweed,Amaranthus hybridus L., is a favorite host of the beet army worm (BAW),Spodoptera exigua L. Chemicals extracted from homogenized pigweed with distilled water, ethanol, or dichloromethane and sprayed back on pigweed deterred oviposition by the BAW. Similarly, water extracts of frass from conspecific larvae or southern armyworm (SAW) larvae,S. eridania (Cramer), fed pigweed leaves and sprayed back on pigweed plants also deterred BAW oviposition, thus confirming that deterrence was due to plant allelochemics rather than specific compounds associated with the metabolic or excretory products of the larvae. Confirmation of the presence of oviposition-deterring chemicals in pigweed was used to explain a previously observed seasonal displacement of BAW by SAW on pigweed in the field.
Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus
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S Poonam
2002-04-01
Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3 at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type, B. t. var. israelensis (mutant and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm, which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm, the culture filtrates of B. t. var. israelensis (wild type and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.
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Jean-Sébastien Pierre
2013-09-01
Full Text Available Understanding mechanisms underlying insects’ host choice and plant susceptibility is important to the study of plant-insect interactions in general, and in the context of plant invasions. This study investigates the oviposition and feeding choices of the specialist weevil Exapion ulicis on the invasive plant species Ulex europaeus, gorse. To do so, we studied the oviposition and feeding preferences of the weevil in choice experiments, using pods and flowers, respectively, from gorses grown in a common garden. The plants used came from regions with different infestation histories: Brittany and Scotland belong to the native range, where the weevil is present, while Reunion and New Zealand belong to the invasive range, where the weevil was not initially introduced with gorse. Results of these experiments suggest that the oviposition choice of E. ulicis females is driven by cues located at the surface of pods and inside them, including pod size and pod seed content. Feeding-choice experiments showed a different pattern of preference compared to oviposition. Taken together with previous studies, our results reveal that E. ulicis uses several traits to choose its host, including whole-plant traits, flower traits and pod traits.
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Elna Mugrabi-Oliveira
1996-01-01
Full Text Available Oviposition site selection of Heliconius erato phyllis (Fabricius, 1775 (Lepidoptera, Nymphalidae was studied when size of and damage on shoots were variable in a natural population of Passiflora suberosa Linnaeus (Passifloraceae, and through sequential and simultaneous choice experiments performed under insectary conditions. Females showed marked oviposition preference for undamaged and largest shoots of P. suberosa. Eggs were mostly laid on the terminal buds of intact shoots under natural conditions. In simultaneous choice trials, females preferred to oviposit on shoots from which leaves (ten were removed but the terminal bud maintained to those where leaves were kept but the terminal bud was cut out. In sequential choice trials, they did not lay eggs on shoots from which the terminal bud was removed. Females preferred to oviposit on large to short intact shoots in both sequential and simultaneous choice trials. Females laid eggs preferentially on shoots with the greatest leaf area when most plants were intact in the field during early spring. Later in fall, when mostly large, old shoots were damaged or in a reproductive stage (less desirable for oviposition, oviposition intensity was highest on the shortest, youngest shoots of P. suberosa. Thus, females might rank these quality attributes higher than size while selecting shoots for oviposition. The consequences of ovipositing selectively on intact, large shoots of P. suberosa are discussed from the view point of H. erato phyllis larval performance.
Induction of oviposition by the administration of oxytocin in hawksbill turtles.
Kawazu, Isao; Kino, Masakatsu; Maeda, Konomi; Yamaguchi, Yasuhiro; Sawamukai, Yutaka
2014-12-01
We set out to develop an oviposition induction technique for captive female hawksbill turtles Eretmochelys imbricata. The infertile eggs of nine females were induced to develop by the administration of follicle-stimulating hormone, after which we investigated the effects of administering oxytocin on oviposition. Seven of the turtles were held in a stationary horizontal position on a retention stand, and then oxytocin was administrated (0.6-0.8 units/kg of body weight; 5 mL). The seven turtles were retained for a mandatory 2 h period after oxytocin administration, and were then returned to the holding tanks. As the control, normal saline (5 mL) was administered to the other two turtles, followed by the administration of oxytocin after 24 h. The eggs in oviducts of all nine turtles were observed by ultrasonography at 24 h after oxytocin administration. The control experiment validated that stationary retention and normal saline administration had no effect on egg oviposition. Eight of the turtles began ovipositing eggs at 17-43 min after oxytocin administration, while one began ovipositing in the holding tank immediately after retention. All turtles finished ovipositing eggs within 24 h of oxytocin administration. This report is the first to demonstrate successful induced oviposition in sea turtles. We suggest that the muscles in the oviducts of hawksbill turtles may respond to relatively lower doses of oxytocin (inducing contractions) compared to land and freshwater turtles (4-40 units/kg) based on existing studies.
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Maria Alice de Medeiros
2009-01-01
Full Text Available A traça-do-tomateiro apresentou maior oviposição ao colonizar tomateiros cultivados em sistema convencional em relação ao orgânico em estudos prévios realizados no campo. Visando confirmar e entender o padrão observado no campo, aspectos bioecológicos como oviposição e mortalidade de imaturos foram comparados em condições semi-controladas de casa de vegetação com plantas cultivadas em vasos com solo proveniente do sistema orgânico e convencional. Adultos da traça-do-tomateiro foram liberados na casa de vegetação e após 24h, as plantas infestadas foram transferidas para outra casa de vegetação, para acompanhamento de coortes horizontais. Os ovos naturalmente depositados pela traça-do-tomateiro foram localizados na planta e demarcados. Em seguida, a folha foi ensacada. Diariamente as plantas foram observadas, registrando a fase de desenvolvimento do inseto e a ocorrência de morte, até que todos os insetos completassem seu ciclo de vida. A oviposição pela traça-do-tomateiro em plantas com solos oriundos do sistema convencional foi duas vezes maior do que em plantas com solos do sistema orgânico. A curva de sobrevivência da fase imatura e a tabela de vida da traça-do-tomateiro em casa de vegetação mostraram que a sobrevivência em plantas com solo orgânico e convencional não apresentaram diferenças. Assim as diferenças no comportamento de padrão de oviposição observadas a campo provavelmente não estão relacionadas com o desempenho da progênie e podem ser influenciado pelo ambiente proporcionado pelo sistema orgânico de produção.The tomato pinworm presented higher oviposition when colonizing tomato plants cropped in conventional system than in organic system, in previous field studies. Aiming to confirm and to understand the observed pattern in the field, bioecological processes, such as oviposition and mortality of immatures, were compared on ploted plants in soil from organic and conventional systems in
Predation and the evolution of complex oviposition behaviour in Amazon rainforest frogs.
Magnusson, William E; Hero, Jean-Marc
1991-05-01
Terrestrial oviposition with free-living aquatic larvae is a common reproductive mode used by amphibians within the central Amazonian rainforest. We investigated the factors presently associated with diversity of microhabitats (waterbodies) that may be maintaining the diversity of reproductive modes. In particular, desiccation, predation by fish, competition with other anurans and water quality were examined in 11 waterbodies as possible forces leading to the evolution of terrestrial oviposition. Predation experiments demonstrated that fish generally do not eat anuran eggs, and that predacious tadpoles and dytiscid beetle larvae are voracious predators of anuran eggs. The percentage of species with terrestrial oviposition was only weakly correlated with the occurrence of pond drying, pH and oxygen concentration, suggesting that anurans in this tropical community are able to use the range of water quality available for egg development. There was a tendency for terrestrial oviposition to be associated with the number of species of tadpoles using the waterbody, but we consider this to be spurious as there was no obvious competitive mechanism that could result in this relationship. The percentage of species with terrestrial oviposition was significantly positively related to our index of egg predation pressure, and negatively related to our index of fish biomass. Egg predation pressure was also negatively related to the index of fish biomass. These results allow us to discount as improbable the hypothesis that predation by fish on anuran eggs was an important selective pressure leading to terrestrial oviposition in this community. The strong positive relationship between terrestrial oviposition and our index of egg predation pressure indicates that these predators have exerted, and are exerting, a significant selective pressure for terrestrial oviposition. The strong negative relationship between the occurrence of fish and the egg predators suggests the surprising
Oviposition strategies of conifer seed chalcids in relation to host phenology
Rouault, Gaëlle; Turgeon, Jean; Candau, Jean-Noël; Roques, Alain; Aderkas, Patrick
2004-10-01
Insects are considered the most important predators of seed cones, the female reproductive structures of conifers, prior to seed dispersal. Slightly more than 100 genera of insects are known to parasitize conifer seed cones. The most diverse (i.e., number of species) of these genera is Megastigmus (Hymenoptera: Torymidae), which comprises many important seed pests of native and exotic conifers. Seed chalcids, Megastigmus spp., lay eggs inside the developing ovules of host conifers and, until recently, oviposition was believed to occur only in fertilized ovules. Ovule development begins just after pollination, but stops if cells are not fertilized. The morphological stage of cone development at the time of oviposition by seed chalcids has been established for many species; however, knowledge of ovule development at that time has been documented for only one species, M. spermotrophus. Megastigmus spermotrophus oviposits in Douglas-fir ovules after pollination but before fertilization. Unlike the unfertilized ovules, those containing a M. spermotrophus larva continue to develop, whether fertilized or not, stressing the need to broaden our understanding of the insect plant interactions for this entire genus. To achieve this task, we reviewed the scientific literature and assembled information pertaining to the timing of oviposition and to the pollination and fertilization periods of their respective host(s). More specifically, we were searching for circumstantial evidence that other species of Megastigmus associated with conifers could behave (i.e., oviposit before ovule fertilization) and impact on female gametophyte (i.e., prevent abortion) like M. spermotrophus. The evidence from our compilation suggests that seed chalcids infesting Pinaceae may also oviposit before ovule fertilization, just like M. spermotrophus, whereas those infesting Cupressaceae seemingly oviposit after ovule fertilization. Based on this evidence, we hypothesize that all species of Megastigmus
Wondwosen, Betelehem; Hill, Sharon R; Birgersson, Göran; Seyoum, Emiru; Tekie, Habte; Ignell, Rickard
2017-01-23
Maize cultivation contributes to the prevalence of malaria mosquitoes and exacerbates malaria transmission in sub-Saharan Africa. The pollen from maize serves as an important larval food source for Anopheles mosquitoes, and females that are able to detect breeding sites where maize pollen is abundant may provide their offspring with selective advantages. Anopheles mosquitoes are hypothesized to locate, discriminate among, and select such sites using olfactory cues, and that synthetic volatile blends can mimic these olfactory-guided behaviours. Two-port olfactometer and two-choice oviposition assays were used to assess the attraction and oviposition preference of gravid Anopheles arabiensis to the headspace of the pollen from two maize cultivars (BH-660 and ZM-521). Bioactive compounds were identified using combined gas chromatography and electroantennographic detection from the headspace of the cultivar found to be most attractive (BH-660). Synthetic blends of the volatile compounds were then assessed for attraction and oviposition preference of gravid An. arabiensis, as above. Here the collected headspace volatiles from the pollen of two maize cultivars was shown to differentially attract and stimulate oviposition in gravid An. arabiensis. Furthermore, a five-component synthetic maize pollen odour blend was identified, which elicited the full oviposition behavioural repertoire of the gravid mosquitoes. The cues identified from maize pollen provide important substrates for the development of novel control measures that modulate gravid female behaviour. Such measures are irrespective of indoor or outdoor feeding and resting patterns, thus providing a much-needed addition to the arsenal of tools that currently target indoor biting mosquitoes.
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Joachim-Bravo Iara S.
2001-01-01
Full Text Available The influence of two factors, age and previous experience, on the oviposition hierarchy preference of Ceratitis capitata (Wiedemann, 1824 females was studied. Two populations were analyzed: one reared in laboratory during 17 years and the other captured in nature. In the first experiment the oviposition preference for four fruits, papaya, orange, banana and apple was tested at the beginning of oviposition period and 20 days past. The results showed that the wild females as much the laboratory ones had an oviposition preference hierarchy at the beginning of peak period of oviposition. However this hierarchic preference disappeared in a later phase of life. In the second experiment the females were previously exposed to fruits of different hierarchic positions and afterwards their choice was tested in respect to the oviposition preference for those fruits. The results showed that there was an influence of the previous experience on the posterior choice of fruits to oviposition when the females were exposed to fruits of lower hierarchic position.
Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females.
Guerra, A A; Martinez, S; Sonia Del Rio, H
1994-07-01
Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.
Macías-Duarte, Alberto; Alvarado-Castro, J Andrés; Dórame-Navarro, María E; Félix-Torres, A Amalia
2009-12-01
Dengue is a serious public health problem worldwide. Biological control of its vector, Aedes aegypti, remains a feasible option in light of increasing urbanization and insecticide resistance. We studied the dispersal and oviposition activity of Toxorhynchites moctezuma in a dengue-endemic urban area in SSonora, Mexico, to provide information about the potential of Toxorhynchites as a control agent for Ae. aegypti in arid areas. We released 210 and 100 laboratory-reared gravid females of Tx. moctezuma in 2 city blocks during the summer and fall of 1993. We set 3 1-liter containers and 1 car tire as sentinel traps at each of 10 backyards within each city block. Spatial and temporal patterns of dispersal and oviposition activity differed between city blocks and between releases. However, a Cox regression analysis showed no significant difference in the per-day probability of Tx. moctezuma oviposition events in sentinel traps between summer and fall releases. Per-day oviposition probability was nearly 5 times greater for sentineltraps that contained larvae of Ae. aegypti, suggesting a high specificity of the predator for its prey. The proportion of sentinel traps positive for Tx. moctezuma eggs did not increase substantially after the 8th day piost-release, reaching 66% and 23% for sentinel traps with and without Ae. aegypti larvae, respectively.
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Lafayette Pereira Candido
2015-12-01
Full Text Available Female Aedes aegypti lay their eggs on nearly any moist substrate. Methods with potential to repel oviposition may reduce infestation, thereby contributing to control of epidemics. We evaluated the influence of Cnidoscolus phyllacanthus and Ricinus communis plant extracts on the oviposition behavior of A. aegypti. Lethal concentrations were first determined in experiments with larvae after 24 h of exposure, after which LC50 and LC90 were used to test oviposition repellency. The experiment consisted of an oviposition preference test based multiple-choice and no-choice assays. The Oviposition Activity Indices (OAIs from the multiple-choice test using both R. communis and C. phyllacanthus were negative, suggesting oviposition repellent and deterrent activity. The LC90 of both plant extracts deterred oviposition by this vector, as demonstrated by an OAI = value of -1. In the choice study, mean oviposition values were significantly different between R. communis and C. phyllacanthus. In the absence of choice, mosquitoes laid eggs independent of the substrate. In conclusion, our OAI values indicate that all substrates used repelled oviposition by A. aegypti.
Ant-Related Oviposition and Larval Performance in a Myrmecophilous Lycaenid
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Matthew D. Trager
2013-01-01
Full Text Available We experimentally assessed ant-related oviposition and larval performance in the Miami blue butterfly (Cyclargus thomasi bethunebakeri. Ant tending had sex-dependent effects on most measures of larval growth: female larvae generally benefitted from increased tending frequency whereas male larvae were usually unaffected. The larger size of female larvae tended by ants resulted in a substantial predicted increase in lifetime egg production. Oviposition by adult females that were tended by C. floridanus ants as larvae was similar between host plants with or without ants. However, they laid relatively more eggs on plants with ants than did females raised without ants, which laid less than a third of their eggs on plants with ants present. In summary, we found conditional benefits for larvae tended by ants that were not accompanied by oviposition preference for plants with ants present, which is a reasonable result for a system in which ant presence at the time of oviposition is not a reliable indicator of future ant presence. More broadly, our results emphasize the importance of considering the consequences of variation in interspecific interactions, life history traits, and multiple measures of performance when evaluating the costs and benefits of mutualistic relationships.
Competing dopamine neurons drive oviposition choice for ethanol in Drosophila.
Azanchi, Reza; Kaun, Karla R; Heberlein, Ulrike
2013-12-24
The neural circuits that mediate behavioral choice evaluate and integrate information from the environment with internal demands and then initiate a behavioral response. Even circuits that support simple decisions remain poorly understood. In Drosophila melanogaster, oviposition on a substrate containing ethanol enhances fitness; however, little is known about the neural mechanisms mediating this important choice behavior. Here, we characterize the neural modulation of this simple choice and show that distinct subsets of dopaminergic neurons compete to either enhance or inhibit egg-laying preference for ethanol-containing food. Moreover, activity in α'β' neurons of the mushroom body and a subset of ellipsoid body ring neurons (R2) is required for this choice. We propose a model where competing dopaminergic systems modulate oviposition preference to adjust to changes in natural oviposition substrates.
Showler, Allan T
2008-02-01
Abscised cotton, Gossypium hirsutum L., fruit in field plots planted at different times were examined to assess adult boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), use of squares and bolls during 2002 and 2003 in the Lower Rio Grande Valley of Texas. Although boll abscission is not necessarily related to infestation, generally more bolls abscised than squares and abundances of fallen bolls were not related to the planting date treatments. During 2003, fallen squares were most abundant in the late-planted treatment. Although large squares (5.5-8-mm-diameter) on the plant are preferred for boll weevil oviposition, diameter of abscised squares is not a reliable measurement because of shrinkage resulting from desiccation and larval feeding. Fallen feeding-punctured squares and bolls were most abundant in late plantings but differences between fallen feeding-punctured squares versus fallen feeding-punctured bolls were found in only one treatment in 2003. During the same year, fallen oviposition-punctured squares were more numerous in the late-planted treatment than in the earlier treatments. Treatment effects were not found on numbers of oviposition-punctured bolls, but fallen oviposition-punctured squares were more common than bolls in the late-planted treatment compared with earlier treatments each year. Dead weevil eggs, larvae, and pupae inside fallen fruit were few and planting date treatment effects were not detected. Living third instars and pupae were more abundant in fallen squares of the late-planted treatment than in the earlier treatments and bolls of all three treatments. This study shows that fallen squares in late-planted cotton contribute more to adult boll weevil populations than bolls, or squares of earlier plantings.
Thompson, Karen J; Jones, Alaine D; Miller, Sandra A
2014-01-01
In female grasshoppers, oviposition is a highly specialized behavior involving a rhythm-generating neural circuit, the oviposition central pattern generator, unusual abdominal appendages, and dedicated muscles. This study of Schistocerca americana (Drury) grasshoppers was undertaken to determine whether the simpler pregenital abdominal segments, which do not contain ovipositor appendages, share common features with the genital segment, suggesting a roadmap for the genesis of oviposition behavior. Our study revealed that although 5 of the standard pregenital body wall muscles were missing in the female genital segment, homologous lateral nerves were, indeed, present and served 4 ovipositor muscles. Retrograde labeling of the corresponding pregenital nerve branches in male and female grasshoppers revealed motor neurons, dorsal unpaired median neurons, and common inhibitor neurons which appear to be structural homologues of those filled from ovipositor muscles. Some pregenital motor neurons displayed pronounced contralateral neurites; in contrast, some ovipositor motor neurons were exclusively ipsilateral. Strong evidence of structural homology was also obtained for pregenital and ovipositor skeletal muscles supplied by the identified neurons and of the pregenital and ovipositor skeletons. For example, transient embryonic segmental appendages were maintained in the female genital segments, giving rise to ovipositor valves, but were lost in pregenital abdominal segments. Significant proportional differences in sternal apodemes and plates were observed, which partially obscure the similarities between the pregenital and genital skeletons. Other changes in reorganization included genital muscles that displayed adult hypertrophy, 1 genital muscle that appeared to represent 2 fused pregenital muscles, and the insertion points of 2 ovipositor muscles that appeared to have been relocated. Together, the comparisons support the idea that the oviposition behavior of genital
Matushkina, Natalia; Lambret, Philippe; Gorb, Stanislav
2016-12-01
Oviposition site selection is a crucial component of habitat selection in dragonflies. The presence of appropriate oviposition plants at breeding waters is considered to be one of the key habitat determinants for species laying eggs endophytically. Thus, Lestes macrostigma, a species which is regarded as threatened in Europe because of its highly disjunct distribution, typically prefers to lay eggs in the sea club rush Bolboschoenus maritimus. However, little is known about how the anatomical and mechanical properties of plant tissues determine the choice of L. macrostigma females. We examined green shoots of six plant species used by L. macrostigma for oviposition, either in the field (actual oviposition plants) or under experimental conditions (potential oviposition plants), to analyse anatomical and mechanical properties of shoots in a framework of known preferences regarding plant substrates for oviposition. As expected, the anatomy of shoots differed between representatives of two plant families, Cyperaceae and Juncaceae, most essentially in the distribution of supporting bundles and the presence of large aeriferous cavities that may affect egg placing within a shoot. The force necessary to puncture the tested plant samples ranged from 360 to 3298 mN, and their local stiffness ranged from 777 to 3363N/m. We show that the shoots of B. maritimus, the plant most preferred by L. macrostigma, have intermediate characteristics regarding both the stiffness and specific anatomical characteristics. The bending stiffness of the ovipositor in L. macrostigma was estimated as 1414N/m, one of the highest values recorded for zygopteran dragonflies so far. The ecological and behavioural implications of plant choice mechanisms in L. macrostigma are discussed in the context of the disjunct distribution of this species. Copyright © 2016 Elsevier GmbH. All rights reserved.
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Xin Yi
Full Text Available Rhodojaponin-III is a nonvolatile botanical grayanoid diterpene compound, which has antifeedant and oviposition deterrence effects against many kinds of insects. However, the molecular mechanism of the chemoreception process remains unknown. In this study, the important role of BdorCSP2 in the recognition of Rhodojaponin-III was identified. The full length cDNA encoding BdorCSP2 was cloned from legs of Bactrocera dorsalis. The results of expression pattern revealed that BdorCSP2 was abundantly expressed in the legs of adult B. dorsalis. Moreover, the expression of BdorCSP2 could be up-regulated by Rhodojaponin-III. In order to gain comprehensive understanding of the recognition process, the binding affinity between BdorCSP2 and Rhodojaponin-III was measured by fluorescence binding assay. Silencing the expression of BdorCSP2 through the ingestion of dsRNA could weaken the effect of oviposition deterrence and antifeedant of Rhodojaponin-III. These results suggested that BdorCSP2 of B. dorsalis could be involved in chemoreception of Rhodojaponin-III and played a critical role in antifeedant and oviposition behaviors induced by Rhodojaponin-III.
Joachim-Bravo, Iara S.; Fernandes, Odair A.; Bortoli, Sérgio A.; Zucoloto, Fernando S.
2001-01-01
The influence of two factors, age and previous experience, on the oviposition hierarchy preference of Ceratitis capitata (Wiedemann, 1824) females was studied. Two populations were analyzed: one reared in laboratory during 17 years and the other captured in nature. In the first experiment the oviposition preference for four fruits, papaya, orange, banana and apple was tested at the beginning of oviposition period and 20 days past. The results showed that the wild females as much the laborator...
Integration of lncRNA–miRNA–mRNA reveals novel insights into oviposition regulation in honey bees
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Xiao Chen
2017-10-01
Full Text Available Background The honey bee (Apis mellifera is a highly diverse species commonly used for honey production and pollination services. The oviposition of the honey bee queen affects the development and overall performance of the colony. To investigate the ovary activation and oviposition processes on a molecular level, a genome-wide analysis of lncRNAs, miRNAs and mRNA expression in the ovaries of the queens was performed to screen for differentially expressed coding and noncoding RNAs. Further analysis identified relevant candidate genes or RNAs. Results The analysis of the RNA profiles in different oviposition phase of the queens revealed that 740 lncRNAs, 81 miRNAs and 5,481 mRNAs were differently expressed during the ovary activation; 88 lncRNAs, 13 miRNAs and 338 mRNAs were differently expressed during the oviposition inhibition process; and finally, 100 lncRNAs, four miRNAs and 497 mRNAs were differently expressed during the oviposition recovery process. In addition, functional annotation of differentially expressed RNAs revealed several pathways that are closely related to oviposition, including hippo, MAPK, notch, Wnt, mTOR, TGF-beta and FoxO signaling pathways. Furthermore, in the QTL region for ovary size, 73 differentially expressed genes and 14 differentially expressed lncRNAs were located, which are considered as candidate genes affecting ovary size and oviposition. Moreover, a core set of genes served as bridges among different miRNAs were identified through the integrated analysis of lncRNA-miRNA-mRNA network. Conclusion The observed dramatic expression changes of coding and noncoding RNAs suggest that they may play a critical role in honey bee queens’ oviposition. The identified candidate genes for oviposition activation and regulation could serve as a resource for further studies of genetic markers of oviposition in honey bees.
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Kamala Jayanthi Pagadala Damodaram
Full Text Available Innate recognition templates (IRTs in insects are developed through many years of evolution. Here we investigated olfactory cues mediating oviposition behavior in the oriental fruit fly, Bactrocera dorsalis, and their role in triggering an IRT for oviposition site recognition. Behavioral assays with electrophysiologically active compounds from a preferred host, mango, revealed that one of the volatiles tested, γ-octalactone, had a powerful effect in eliciting oviposition by gravid B. dorsalis females. Electrophysiological responses were obtained and flies clearly differentiated between treated and untreated substrates over a wide range of concentrations of γ-octalactone. It triggered an innate response in flies, overriding inputs from other modalities required for oviposition site evaluation. A complex blend of mango volatiles not containing γ-octalactone elicited low levels of oviposition, whereas γ-octalactone alone elicited more oviposition response. Naïve flies with different rearing histories showed similar responses to γ-octalactone. Taken together, these results indicate that oviposition site selection in B. dorsalis is mediated through an IRT tuned to γ-octalactone. Our study provides empirical data on a cue underpinning innate behavior and may also find use in control operations against this invasive horticultural pest.
Oviposition behavior of the silver leaf whitefly Bemisia tabaci biotype B on tomato
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Vendramim, Jose D.; Souza, Antonio P. de; Ongarelli, Maria das G.
2009-01-01
The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)
Wasserberg, Gideon; White, L; Bullard, A; King, J; Maxwell, R
2013-09-01
For organisms lacking parental care and where larval dispersal is limited, oviposition site selection decisions are critical fitness-enhancing choices. However, studies usually do not consider the interdependence of the two. In this study, we evaluated the effect of food level on the oviposition behavior of Aedes albopictus (Skuse) in the presence or the absence of a nonlethal predator (caged dragonfly nymph). We also attempted to quantify the perceived cost of predation to ovipositioning mosquitoes. Mosquitoes were presented with oviposition cups containing four levels of larval food (fermented leaf infusion) with or without a caged libellulid nymph. By titrating larval food, we estimated the amount of food needed to attract the female mosquito to oviposit in the riskier habitat. As expected, oviposition rate increased with food level and decreased in the presence of a predator. However, the effect of food level did not differ between predator treatments. By calculating the difference in the amount of food for points of equal oviposition rate in the predator-present and predator-absent regression lines, we estimated the cost of predation risk to be 1950 colony-forming-units per milliliter. Our study demonstrated the importance of considering the possible interdependence of predation risk and food abundance for oviposition-site-seeking insects. This study also quantified the perceived cost of predation and found it to be relatively low, a fact with positive implications for biological control.
The Effect of Open Brood and Colony Strength on the Onset of Oviposition by Queen Bees
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Gąbka Jakub
2014-06-01
Full Text Available In bee colonies without open brood, e.g., after swarming, there is no need for royal jelly, and nurse bees thus do not produce it. According to many beekeepers, adding combs with open brood restarts the production of royal jelly by nurse bees, and the virgin queens then are better fed and start earlier oviposition. The purpose of this study was to investigate whether the presence of open brood and the strength of the colonies affect the onset of oviposition by queen bees. Open brood in colonies with virgins before and during mating flights did not accelerate the initiation of oviposition by the queens. In addition, no differences were identified in starting oviposition by queens in strong colonies of more than 30,000 worker bees, or in weak colonies with up to 1,000 workers. Overall, the results showed that neither open brood in the nests, nor the strength of the colonies affects the onset of oviposition by queen bees.
Mukae, Shin-Ya; Ohashi, Toshiki; Matsumoto, Yuika; Ohta, Shinji; Ômura, Hisashi
2016-11-01
The common grass yellow butterfly, Eurema mandarina (formerly Eurema hecabe mandarina) (Lepidoptera, Pieridae), recently has been separated taxonomically from a subtropical population of Eurema hecabe in Japan. This species is widely distributed in the temperate region of Japan, and feeds mainly on various ligneous plants within the Fabaceae. We attempted to identify an oviposition stimulant for E. mandarina from its primary hosts, Albizia julibrissin and Lespedeza cuneata. In both hosts, crude extract and an aqueous fraction elicited oviposition responses from gravid females. A polar subfraction of the aqueous fraction also stimulated high oviposition-stimulatory activity, comparable to the original aqueous fraction, suggesting that E. mandarina females use water-soluble compounds for host recognition. Subsequent activity-directed fractionation by ion exchange chromatography indicated that one of the key substances was contained in the neutral/amphoteric fraction. Chemical analyses revealed that the active fractions of both hosts contained D-(+)-pinitol as the major component. We examined female responses to authentic D-pinitol and found that it induced oviposition responses at concentrations greater than 0.1 %. Since this cyclitol is omnipresent in Fabaceae, we conclude that D-pinitol plays a role in mediating oviposition of E. mandarina on fabaceous plants.
Sambaraju, Kishan R; Donelson, Sarah L; Bozic, Janko; Phillips, Thomas W
2016-01-22
The oviposition behavior of the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), a major insect pest of durable stored foods, was studied in small experimental arenas under laboratory conditions using videography, and a time budget analysis of its behaviors was documented. Resting gravid females typically became active shortly after the start of the scotophase. The characteristic behaviors exhibited by mated females prior to oviposition included antennal movement, grooming of antennae and mouth parts using the forelegs, walking or flying, and abdomen bending and dragging. Pre-oviposition behaviors such as antennal grooming and walking or flying were observed to alternate several times before females commenced the abdominal dragging behavior that preceded egg laying. Eggs were laid singly or sometimes in groups, either freely or stuck to food material. Gravid females showed little or no movement during the photophase; however, they actively flew and oviposited during the scotophase. Females allocated only a small portion of their time to oviposition while the rest of the time was spent away from food. Females oviposited on food material by making repeated visits, predominantly during the first four hours of the scotophase. Visits and time spent on food declined as the scotophase advanced.
Institute of Scientific and Technical Information of China (English)
Mao-xinZhang; BingLing; Shao-yingChen; Guang-wenLiang; Xiong-feiPang
2004-01-01
Repellent and oviposition deterrent activities of the essential oil from Mikania micrantha and five volatile compounds including limonene, a-terpinene, linalool, B-caryophylene and verbenone on the diamondback moth (DBM), Plutella xylostella, was investigated in door and in net-house. The results showed that the essential oil of the M. micrantha had significant repellant effect (at flow 100-180 mL/min) and oviposition deterrent activity at dose 1020 uL/seedling for the DBM. In five volatile compounds, a-terpinene, limonene and linalool had significant effect on repellent and oviposition deterrent of the DBM moths, but verbenone and B-caryophylene, no significantly effect was observed in repellent and oviposition deterrent.
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Lima, Larissa C. de; Campos, Alcebiades R.
2008-01-01
Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)
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Kishan R. Sambaraju
2016-01-01
Full Text Available The oviposition behavior of the Indian meal moth, Plodia interpunctella (Hübner (Lepidoptera: Pyralidae, a major insect pest of durable stored foods, was studied in small experimental arenas under laboratory conditions using videography, and a time budget analysis of its behaviors was documented. Resting gravid females typically became active shortly after the start of the scotophase. The characteristic behaviors exhibited by mated females prior to oviposition included antennal movement, grooming of antennae and mouth parts using the forelegs, walking or flying, and abdomen bending and dragging. Pre-oviposition behaviors such as antennal grooming and walking or flying were observed to alternate several times before females commenced the abdominal dragging behavior that preceded egg laying. Eggs were laid singly or sometimes in groups, either freely or stuck to food material. Gravid females showed little or no movement during the photophase; however, they actively flew and oviposited during the scotophase. Females allocated only a small portion of their time to oviposition while the rest of the time was spent away from food. Females oviposited on food material by making repeated visits, predominantly during the first four hours of the scotophase. Visits and time spent on food declined as the scotophase advanced.
Predatory mites avoid ovipositing near counter-attacking prey
Faraji, F.; Janssen, A.; Sabelis, M.W.
2001-01-01
Attacking prey is not without risk; predators may endure counterattackby the prey. Here, we study the oviposition behaviour of a predatory mite(Iphiseius degenerans) in relation to its prey, thewesternflower thrips (Frankliniella occidentalis). This thrips iscapable of killing the eggs of the
Searching and oviposition behavior of aphidophagous hoverflies (Diptera: Syrphidae: a review
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Raki A.
2009-01-01
Full Text Available Aphidophagous hoverflies forage according two different host-finding mechanisms: they forage for suitable food sources (for their energy-expensive hovering flight, and for protein to mature their reproductive system, and for suitable oviposition sites. Syrphids are highly mobile, enabling them to lay eggs over large areas, and to locate aphid colonies earlier in the season than other aphidophaga. The result is that most syrphid eggs tend to be laid close to aphid colonies. The choice of oviposition sites may be crucial for offspring performance because the neonate larvae have limited dispersal ability. Selection of aphid patches should therefore reflect nutritional value, risk of predation and competition pressure. Several factors are known to affect the choice of oviposition site: habitat, host plant, aphid species, aphid availability, semiochemicals, the presence of intra- or interspecific competitors and female age. We review here the available information on these factors in order to understand the mechanisms of decision-making by syrphid females during their egg-laying behavior, a crucial aspect of their effective use in strategies of the biological control of aphids.
Rigsby, Chad M; McCartney, Nathaniel B; Herms, Daniel A; Tumlinson, James H; Cipollini, Don
2017-08-01
Emerald ash borer (EAB; Agrilus planipennis) is a devastating pest of ash (Fraxinus spp.) in its invaded range in North America. Its coevolved Asian hosts are more resistant and less preferred for oviposition than susceptible North American species. We compared EAB oviposition preferences and bark and canopy volatile organic compound (VOC) emissions of resistant Manchurian ash and susceptible black ash, and examined relationships between VOC profiles and oviposition. In the field, black ash was highly preferred for oviposition while no eggs were laid on Manchurian ash, and we found clear differences in the VOC profiles of Manchurian and black ash. We detected 78 compounds emitted from these species, including 16 compounds that elicited EAB antennal activity in prior studies. Four compounds were unique to black and 11 to Manchurian ash. Emission rates of 14 canopy and 19 bark volatiles varied among the two species, including four previously reported as antennally active. Specifically, 7-epi-sesquithujene (bark) emissions were greater from black ash, while β-caryophyllene (canopy), linalool (bark), and α-cubebene (bark) were emitted at higher rates by Manchurian ash. No relationships were found between the emission rate of any single compound or group of compounds (e.g. monoterpenes) suggesting that preference may be based on complex profile combinations. This is the first study to directly compare VOCs of black and Manchurian ash as well as the first to examine bark- and canopy-specific VOCs. The unique bark and canopy VOC profiles of these two species implicates potentially important variation in VOCs between a closely related resistant and susceptible species that provides a foundation for future studies of host preferences of EAB.
Veen, Johan Wilhelm van
1999-01-01
We examined the food provisioning and oviposition process (POP) for worker- and gyne-producing cells of Melipona beecheii. POPs for both castes did not differ significantly in duration and number of trophic eggs oviposited by workers in the cells. The frequency of food discharges by workers in
Ma, Y.F.; Xiao, C.
2013-01-01
The push-pull effects of three plant secondary metabolites, azadirachtin, eucalyptol, and heptanal, on the oviposition choices of potato tubers by the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) were tested in the laboratory. Azadirachtin at concentrations from 1.5 to 12 mg/L had a significant repellent effect on oviposition. Eucalyptol at concentrations from 3 to 12 mg/L promoted oviposition. Heptanal promoted oviposition at low concentrations from 0.1875 to 3.0 mg/L but repelled it at higher concentrations from 12 to 24 mg/L. The combination of azadirachtin (12 mg/L) with eucalyptol (3.0 mg/L) resulted in a significant pushpull effect of 56.3% on oviposition. The average maximum push-pull effects occurred with the combinations of azadirachtin with heptanal (12 and 0.375 mg/L, respectively; 38.7% push-pull effect), heptanal with eucalyptol (12 and 6 mg/L, respectively; 31.4% push-pull effect), and heptanal (high concentration) with heptanal (low concentration) (12.0 and 0.375 mg/L, respectively; 25% push-pull effect). PMID:24786822
Morino, Chisato; Morita, Yusuke; Minami, Kazuki; Nishidono, Yuto; Nakashima, Yoshitaka; Ozawa, Rika; Takabayashi, Junji; Ono, Naoaki; Kanaya, Shigehiko; Tamura, Takayuki; Tezuka, Yasuhiro; Tanaka, Ken
2018-01-01
Umbelliferous medicinal plants, such as Angelica acutiloba Kitagawa and Angelica dahurica Bentham et Hooker filius ex Franchet et Savatier, account for a large percentage of crude drug consumption in Japan. The most serious problem in the cultivation of umbelliferous medicinal plants is the feeding damage caused by the common yellow swallowtail (Papilio machaon hippocrates C. & R. Felder, 1864). When we compared the numbers of eggs laid by P. machaon on six umbelliferous medicinal plants, the eggs on A. acutiloba, A. dahurica, and Glehnia littoralis Fr. Schmidt ex Miquel were the most numerous, those on Saposhnikovia divaricata Schischkin and Cnidium officinale Makino were rare, and Bupleurum falcatum Linné was not oviposited at all. To identify oviposition inhibitors for P. machaon in B. falcatum, S. divaricata, and C. officinale, the volatile chemical constituents of these umbelliferous medicinal plants were compared with GC-MS. We carried out multivariate analysis of gas chromatographic data and concluded that germacrene D, α-humulene, and trans-caryophyllene play important roles in protecting plants from oviposition by P. machaon. Their oviposition repellent activity was confirmed by the fact that the number of eggs laid on the leaves around a repellent device containing a mixture of germacrene D, α-humulene, and trans-caryophyllene was reduced by 40% compared to a control.
International Nuclear Information System (INIS)
Miyatake, T.; Irabu, T.; Higa, R.
1993-01-01
Oviposition punctures caused by sterile females of the tephritid Bactrocera cucurbitae in cucurbit fruits were examined and economic damage was evaluated in Okinawa, Ryukyu Archipelago, Japan. Cage experiments in the field confirmed that sterile females make punctures (sterile stings) on fruits. The features of sterile stings differed depending on fruit species and were classified into 5 types
Oviposition-stimulant and ovicidal activities of Moringa oleifera lectin on Aedes aegypti.
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Nataly Diniz de Lima Santos
Full Text Available Natural insecticides against the vector mosquito Aedes aegypti have been the object of research due to their high level of eco-safety. The water-soluble Moringa oleifera lectin (WSMoL is a larvicidal agent against A. aegypti. This work reports the effects of WSMoL on oviposition and egg hatching of A. aegypti.WSMoL crude preparations (seed extract and 0-60 protein fraction, at 0.1 mg/mL protein concentration, did not affect oviposition, while A. aegypti gravid females laid their eggs preferentially (73% in vessels containing isolated WSMoL (0.1 mg/mL, compared with vessels containing only distilled water (control. Volatile compounds were not detected in WSMoL preparation. The hatchability of fresh eggs deposited in the solutions in the oviposition assay was evaluated. The numbers of hatched larvae in seed extract, 0-60 protein fraction and WSMoL were 45 ± 8.7 %, 20 ± 11 % and 55 ± 7.5 %, respectively, significantly (p<0.05 lower than in controls containing only distilled water (75-95%. Embryos were visualized inside fresh control eggs, but not within eggs that were laid and maintained in WSMoL solution. Ovicidal activity was also assessed using stored A. aegypti eggs. The protein concentrations able to reduce the hatching rate by 50% (EC50 were 0.32, 0.16 and 0.1 mg/mL for seed extract, 0-60 protein fraction and WSMoL, respectively. The absence of hatching of stored eggs treated with WSMoL at 0.3 mg/mL (EC99 after transfer to medium without lectin indicates that embryos within the eggs were killed by WSMoL. The reduction in hatching rate of A. aegypti was not linked to decrease in bacteria population.WSMoL acted both as a chemical stimulant cue for ovipositing females and ovicidal agent at a given concentration. The oviposition-stimulant and ovicidal activities, combined with the previously reported larvicidal activity, make WSMoL a very interesting candidate in integrated A. aegypti control.
Predation-related odours reduce oviposition in a herbivorous mite.
Choh, Yasuyuki; Uefune, Masayoshi; Takabayashi, Junji
2010-01-01
When adult females of the herbivorous mite, Tetranychus urticae, were exposed to the predatory mite, Phytoseiulus persimilis, they laid fewer eggs than females that had not been exposed to P. persimilis when transferred onto a new leaf patch. However, when T. urticae females were exposed to either products of P. persimilis or artificially damaged conspecific eggs on a leaf patch, the number of T. urticae eggs on a new leaf patch did not differ significantly from the control. The reduced oviposition was neither due to the feeding activity on the leaf patch with P. persimilis nor to that on the new leaf patch. There was also no significant difference between the number of T. urticae eggs produced on a new leaf patch following exposure to the odours of a neighbouring leaf patch where there had previously been either P. persimilis or T. urticae adults. However, female T. urticae that had been exposed to odours from neighbouring leaf patches on which both T. urticae and P. persimilis had been placed produced significantly fewer eggs on a new leaf patch than those that had not been exposed to such odours. Neither odours from neighbouring intact leaf patches on which T. urticae eggs were preyed on by P. persimilis, nor odours from a neighbouring Parafilm patch on which T. urticae was preyed on by P. persimilis affected the oviposition of T. urticae. These data suggest that the presence of T. urticae, P. persimilis and a leaf patch are needed for the emission of odours to reduce oviposition in T. urticae.
Grigolli, J F J; Souza, L A; Fernandes, M G; Busoli, A C
2017-08-01
The cotton boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the main pest in cotton crop around the world, directly affecting cotton production. In order to establish a sequential sampling plan, it is crucial to understand the spatial distribution of the pest population and the damage it causes to the crop through the different developmental stages of cotton plants. Therefore, this study aimed to investigate the spatial distribution of adults in the cultivation area and their oviposition and feeding behavior throughout the development of the cotton plants. The experiment was conducted in Maracaju, Mato Grosso do Sul, Brazil, in the 2012/2013 and 2013/2014 growing seasons, in an area of 10,000 m 2 , planted with the cotton cultivar FM 993. The experimental area was divided into 100 plots of 100 m 2 (10 × 10 m) each, and five plants per plot were sampled weekly throughout the crop cycle. The number of flower buds with feeding and oviposition punctures and of adult A. grandis was recorded throughout the crop cycle in five plants per plot. After determining the aggregation indices (variance/mean ratio, Morisita's index, exponent k of the negative binomial distribution, and Green's coefficient) and adjusting the frequencies observed in the field to the distribution of frequencies (Poisson, negative binomial, and positive binomial) using the chi-squared test, it was observed that flower buds with punctures derived from feeding, oviposition, and feeding + oviposition showed an aggregated distribution in the cultivation area until 85 days after emergence and a random distribution after this stage. The adults of A. grandis presented a random distribution in the cultivation area.
International Nuclear Information System (INIS)
Alberts, A.C.
1995-01-01
The ability to noninvasively estimate clutch size and predict oviposition date in reptiles can be useful not only to veterinary clinicians but also to managers of captive collections and field researchers. Measurements of egg size and shape, as well as position of the clutch within the coelomic cavity, were taken from diagnostic radiographs of 20 female Cuban rock iguanas, Cyclura nubila, 81 to 18 days prior to laying. Combined with data on maternal body size, these variables were entered into multiple regression models to predict clutch size and timing of egg laying. The model for clutch size was accurate to 0.53 ± 0.08 eggs, while the model for oviposition date was accurate to 6.22 ± 0.81 days. Equations were generated that should be applicable to this and other large Cyclura species. © 1995 Wiley-Liss, Inc
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Eric W. Riddick
2015-09-01
Full Text Available The limited availability of alternative foods to replace natural prey hinders cost-effective mass production of ladybird beetles for augmentative biological control. We compared the effects of powdered vs. whole Artemia franciscana (A. franciscana (brine shrimp eggs with or without a dietary supplement on development and reproduction of Coleomegilla maculata (C. maculata (Coleoptera: Coccinellidae. We tested the hypotheses that (1 powdered A. franciscana eggs are more suitable than whole eggs; and (2 palmitic acid, a common fatty acid in natural prey, i.e., aphids, is an effective dietary supplement. Development time, pre-imaginal survival, sex ratio, and body weight of adults did not differ significantly amongst individuals fed powdered vs. whole eggs, with or without 5% palmitic acid. Significantly more oviposition occurred when females were fed powdered eggs than whole eggs and powdered eggs with 5% palmitic acid than whole eggs with or without 5% palmitic acid. A weak functional relationship was found between pre-oviposition time and total oviposition by females fed powdered eggs with 5% palmitic acid; pre-oviposition time decreased as oviposition increased. Food treatments had no significant differential effect on progeny (egg hatch rate. In conclusion, a simple change in A. franciscana egg texture and particle size (i.e., blending whole eggs into a dust-like powder increases oviposition in C. maculata. Supplementing powdered eggs with 5% palmitic acid might accelerate oogenesis (egg maturation in some females.
First record of invasive Burmese Python oviposition and brooding inside an anthropogenic structure
Hanslowe, Emma; Falk, Bryan; Collier, Michelle A. M.; Josimovich, Jillian; Rahill, Thomas; Reed, Robert
2016-01-01
We discovered an adult female Python bivittatus (Burmese Python) coiled around a clutch of 25 eggs in a cement culvert in Flamingo, FL, in Everglades National Park. To our knowledge, this is the first record of an invasive Burmese Python laying eggs and brooding inside an anthropogenic structure in Florida. A 92% hatch-success rate suggests that the cement culvert provided suitable conditions for oviposition, embryonic development, and hatching. Given the plenitude of such anthropogenic structures across the landscape, available sites for oviposition and brooding may not be limiting for the invasive Burmese Python population.
Taxonomic variation in oviposition by tailed frogs (Aschaphus spp.).
Nancy E. Karraker; David S. Pilliod; Michael J. Adams; Evelyn L. Bull; Paul Stephen Corn; Lowell V. Diller; Linda A. Dupuis; Marc P. Hayes; Blake R. Hossack; Garth R. Hodgson; Erin J. Hyde; Kirk Lohman; Bradford R. Norman; Lisa M. Ollivier; Christopher A. Pearl; Charles R. Peterson
2006-01-01
Tailed frogs (Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular...
Villanueva, Raul T; Walgenbach, James F
2005-12-01
Eight reduced-risk insecticides (acetamiprid, thiamethoxam, imidacloprid, thiacloprid, methoxyfenozide, pyriproxyfen, indoxacarb, and spinosad) and three conventional insecticides (azinphosmethyl, fenpropathrin, and esfenvalerate) were tested against Neoseiulus fallacis (Garman) (Acari: Phytoseiidae), the most abundant predacious mite in North Carolina apple (Malus spp.) orchards. To assess the effect of insecticides on development and mortality of N. fallacis immatures, 12-h-old eggs were individually placed on bean leaf disks previously dipped in insecticide solutions. Tetranychus urticae Koch (Acari: Tetranychidae) females were added as a food source. None of the reduced-risk insecticides significantly affected immature N. fallacis compared with the control; however, the pyrethroids esfenvalerate and fenpropathrin were highly toxic to immatures. To evaluate the effect of insecticides on mortality and oviposition of adult N. fallacis, 7- to 8-d-old females were confined on insecticide-treated bean leaves with Malephora crocea (Aizoaceae) pollen added as a food source. Spinosad resulted in the highest mortality, whereas azinphosmethyl, acetamiprid, fenpropathrin, and imidacloprid were moderately toxic, and mortality from esfenvalerate, indoxacarb, thiacloprid, methoxyfenozide, pyriproxyfen, and thiamethoxam did not differ significantly from the control. Oviposition was affected in a similar manner, with the exception of acetamiprid that did not affect oviposition, and thiamethoxam that reduced oviposition.
Integration of multiple intraguild predator cues for oviposition decisions by a predatory mite
Walzer, Andreas; Schausberger, Peter
2012-01-01
In mutual intraguild predation (IGP), the role of individual guild members is strongly context dependent and, during ontogeny, can shift from an intraguild (IG) prey to a food competitor or to an IG predator. Consequently, recognition of an offspring's predator is more complex for IG than classic prey females. Thus, IG prey females should be able to modulate their oviposition decisions by integrating multiple IG predator cues and by experience. Using a guild of plant-inhabiting predatory mites sharing the spider mite Tetranychus urticae as prey and passing through ontogenetic role shifts in mutual IGP, we assessed the effects of single and combined direct cues of the IG predator Amblyseius andersoni (eggs and traces left by a female on the substrate) on prey patch selection and oviposition behaviour of naïve and IG predator-experienced IG prey females of Phytoseiulus persimilis. The IG prey females preferentially resided in patches without predator cues when the alternative patch contained traces of predator females or the cue combination. Preferential egg placement in patches without predator cues was only apparent in the choice situation with the cue combination. Experience increased the responsiveness of females exposed to the IG predator cue combination, indicated by immediate selection of the prey patch without predator cues and almost perfect oviposition avoidance in patches with the cue combination. We argue that the evolution of the ability of IG prey females to evaluate offspring's IGP risk accurately is driven by the irreversibility of oviposition and the functionally complex relationships between predator guild members. PMID:23264692
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Ruchi Yadav
2014-12-01
Full Text Available Mosquitoes are well known as vectors of several disease causing pathogens. The extensive use of synthetic insecticides in the mosquito control strategies resulted to the development of pesticide resistance and fostered environmental deterioration. Hence in recent years plants become alternative source of mosquito control agents. The present study assessed the larvicidal and oviposition altering activity of six different plants species-Alstonia scholaris, Callistemon viminalis, Hyptis suaveolens, Malvastrum coromandelianum, Prosopis juliflora, Vernonia cinerea against Aedes albopictus mosquito in laboratory.Leaf extracts of all the six plants species in five different solvents of various polarities were used in the range of 20-400ppm for larval bioassay and 50,100 and 200ppm for cage bioassay (for the study of oviposition behavior against Ae. albopictus. The larval mortality data were recorded after 24 h and subjected to Probit analysis to determine the lethal concentrations (LC50, while OAI (Oviposition activity index was calculated for oviposition altering activity of the plant extracts.Vernonia cinerea extract in acetone and C. viminalis extract in isopropanol were highly effective against Aedes albopictus larvae with LC50 value 64.57, 71.34ppm respectively. Acetone extract of P. juliflora found to be strong oviposition-deterrent which inhibited >2 fold egg laying (OAI-0.466 at 100ppm.Vernonia cinerea and C. viminallis leaf extracts have the potential to be used as larvicide and P. juliflora as an oviposition-deterrent for the control of Ae. albopictus mosquito.
Yadav, Ruchi; Tyagi, Varun; Tikar, Sachin N; Sharma, Ajay K; Mendki, Murlidhar J; Jain, Ashok K; Sukumaran, Devanathan
2014-01-01
Background: Mosquitoes are well known as vectors of several disease causing pathogens. The extensive use of synthetic insecticides in the mosquito control strategies resulted to the development of pesticide resistance and fostered environmental deterioration. Hence in recent years plants become alternative source of mosquito control agents. The present study assessed the larvicidal and oviposition altering activity of six different plants species-Alstonia scholaris, Callistemon viminalis, Hyptis suaveolens, Malvastrum coromandelianum, Prosopis juliflora, Vernonia cinerea against Aedes albopictus mosquito in laboratory. Methods: Leaf extracts of all the six plants species in five different solvents of various polarities were used in the range of 20–400ppm for larval bioassay and 50,100 and 200ppm for cage bioassay (for the study of oviposition behavior) against Ae. albopictus. The larval mortality data were recorded after 24 h and subjected to Probit analysis to determine the lethal concentrations (LC50), while OAI (Oviposition activity index) was calculated for oviposition altering activity of the plant extracts. Results: Vernonia cinerea extract in acetone and C. viminalis extract in isopropanol were highly effective against Aedes albopictus larvae with LC50 value 64.57, 71.34ppm respectively. Acetone extract of P. juliflora found to be strong oviposition-deterrent which inhibited >2 fold egg laying (OAI-0.466) at 100ppm. Conclusion: Vernonia cinerea and C. viminallis leaf extracts have the potential to be used as larvicide and P. juliflora as an oviposition-deterrent for the control of Ae. albopictus mosquito. PMID:26114131
George, Kelly A; Archer, Melanie S; Toop, Tes
2015-01-01
This study explored the molecular mechanisms potentially underlying blow fly nocturnal oviposition. A behavioral study revealed that Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) possesses a diel rhythm of oviposition in light under 12:12 light/dark conditions. Reversal to 12:12 dark/light resulted in oviposition behavior changing to align with the adjusted regime in most females, but four of 59 experimental females lacked a diel rhythm of oviposition (were arrhythmic). Real-time PCR was used to monitor the molecular expression levels of known circadian genes per and tim in C. vicina to determine whether gene expression and behavior correlated. As with behavior, reversing light/dark conditions changed rhythmic gene expression to align with an adjusted light regime. This suggests that although it is unlikely that C. vicina will colonize dead bodies at night, arrhythmic females and oviposition in the dark was demonstrated. © 2014 American Academy of Forensic Sciences.
Suverkropp, B.P.; Dutton, A.; Bigler, F.; Lenteren, van J.C.
2008-01-01
Oviposition behaviour and egg distribution of Ostrinia nubilalis is reviewed based on published information and new research. The position of egg masses of O. nubilalis on maize plants and leaves were sampled in the field. Most egg masses were found on the lower leaf side, on the middle part of the
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Diones Krinski
2013-09-01
Full Text Available Aiming to contribute to a rearing methodology for the brown stink bug, Euschistus heros, in the laboratory, we evaluated oviposition on artificial substrates of different colors. During six days, oviposition was evaluated daily, by counting the total number of eggs, number of clutches, and eggs/clutch. Females laid 12,463 eggs, in 1,677 clutches, resulting in an average of 7.28 ± 0.44 eggs/clutch. Black, brown, and green felt had the most eggs and clutches. The results demonstrated that many colors are suitable as oviposition substrate for E. heros, providing information for the mass rearing of this insect.
Fei, Minghui; Harvey, Jeffrey A.; Yin, Yi; Gols, Rieta
2017-01-01
The effects of temporal variation in the quality of short-lived annual plants on oviposition preference and larval performance of insect herbivores has thus far received little attention. This study examines the effects of plant age on female oviposition preference and offspring performance in the
Owens, D; Nuessly, G S; Kendra, P E; Colquhoun, T A; Seal, D R
2017-08-01
Fresh market sweet corn (Zea mays L., convar. saccharata var. rugosa, Poales: Poaceae) ears produced in Florida are damaged by the larvae of Euxesta stigmatias Loew, Euxesta eluta Loew, and Chaetopsis massyla Walker (Diptera: Ulidiidae) that renders ears unmarketable. No standard lure exists for monitoring these pests. Oviposition substrate and attractant bioassays were designed to identify attractive substrates for further semiochemical investigation. Frass from the fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), was more attractive than other ovipositional substrates tested for E. eluta and C. massyla, and resulted in greater ovipositional output. Tassel-derived armyworm frass was more attractive than leaf-derived frass for oviposition. Frass also resulted in greater oviposition output by two species. In attraction bioassays, frass was generally preferred over the corresponding corn tissue, and only C. massyla demonstrated a preference for silk-frass over tassel-frass. The most promising substrates were then evaluated by electroantennography (EAG) to quantify olfactory responses. Frass volatiles also elicited greater antennal responses than corn volatiles. With tassel-frass, greater amplitude EAG responses were recorded from immature E. eluta female antennae, while mature female E. stigmatias exhibited greater responses. Equivalent antennal response to silk-frass was observed from E. eluta. Overall, silk-frass elicited the greatest EAG responses among all three fly species. Our results indicate that armyworm frass is an important resource in the chemical ecology of corn-infesting silk flies, and this substrate warrants further investigation for potential attractants that may facilitate development of novel management tools for these pests. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
2014-01-01
Background Transgenic crops expressing Bt toxins have substantial benefits for growers in terms of reduced synthetic insecticide inputs, area-wide pest management and yield. This valuable technology depends upon delaying the evolution of resistance. The ‘high dose/refuge strategy’, in which a refuge of non-Bt plants is planted in close proximity to the Bt crop, is the foundation of most existing resistance management. Most theoretical analyses of the high dose/refuge strategy assume random oviposition across refugia and Bt crops. Results In this study we examined oviposition and survival of Spodoptera frugiperda across conventional and Bt maize and explored the impact of oviposition behavior on the evolution of resistance in simulation models. Over six growing seasons oviposition rates per plant were higher in Bt crops than in refugia. The Cry1F Bt maize variety retained largely undamaged leaves, and oviposition preference was correlated with the level of feeding damage in the refuge. In simulation models, damage-avoiding oviposition accelerated the evolution of resistance and either led to requirements for larger refugia or undermined resistance management altogether. Since larval densities affected oviposition preferences, pest population dynamics affected resistance evolution: larger refugia were weakly beneficial for resistance management if they increased pest population sizes and the concomitant degree of leaf damage. Conclusions Damaged host plants have reduced attractiveness to many insect pests, and crops expressing Bt toxins are generally less damaged than conventional counterparts. Resistance management strategies should take account of this behavior, as it has the potential to undermine the effectiveness of existing practice, especially in the tropics where many pests are polyvoltinous. Efforts to bring down total pest population sizes and/or increase the attractiveness of damaged conventional plants will have substantial benefits for slowing the
Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates.
Majer, A P; Vedolin, M C; Turra, A
2012-06-01
Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.
Yang, Shih-Tsai; Shiao, Shiuh-Feng
2012-03-01
Necrophagous blow fly species (Diptera: Calliphoridae) are the most important agents for estimating the postmortem interval (PMI) in forensic entomology. Nevertheless, the oviposition preferences of blow flies may cause a bias of PMI estimations because of a delay or acceleration of egg laying. Chrysomya megacephala (F.) and C. rufifacies (Macquart) are two predominant necrophagous blow fly species in Taiwan. Their larvae undergo rather intense competition, and the latter one can prey on the former under natural conditions. To understand the oviposition preferences of these two species, a dual-choice device was used to test the choice of oviposition sites by females. Results showed when pork liver with and without larvae of C. rufifacies was provided, C. megacephala preferred to lay eggs on the liver without larvae. However, C. megacephala showed no preference when pork liver with and without conspecific larvae or larvae of Hemipyrellia ligurriens (Wiedemann) was provided. These results indicate that females of C. megacephala try to avoid laying eggs around larvae of facultatively predaceous species of C. rufifacies. However, C. rufifacies showed significant oviposition preference for pork liver with larvae of C. megacephala or conspecific ones when compared with pork liver with no larvae. These results probably imply that conspecific larvae or larvae of C. megacephala may potentially be alternative food resources for C. rufifacies, so that its females prefer to lay eggs in their presence. When considering the size of the oviposition media, pork livers of a relatively small size were obviously unfavorable to both species. This may be because females need to find sufficient resources to meet the food demands of their larvae. In another experiment, neither blow fly species showed an oviposition preference for pork livers of different stages of decay. In addition, the oviposition preferences of both species to those media with larvae were greatly disturbed in a dark
Electric nets and sticky materials for analysing oviposition behaviour of gravid malaria vectors
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Dugassa Sisay
2012-11-01
Full Text Available Abstract Background Little is known about how malaria mosquitoes locate oviposition sites in nature. Such knowledge is important to help devise monitoring and control measures that could be used to target gravid females. This study set out to develop a suite of tools that can be used to study the attraction of gravid Anopheles gambiae s.s. towards visual or olfactory cues associated with aquatic habitats. Methods Firstly, the study developed and assessed methods for using electrocuting nets to analyse the orientation of gravid females towards an aquatic habitat. Electric nets (1m high × 0.5m wide were powered by a 12V battery via a spark box. High and low energy settings were compared for mosquito electrocution and a collection device developed to retain electrocuted mosquitoes when falling to the ground. Secondly, a range of sticky materials and a detergent were tested to quantify if and where gravid females land to lay their eggs, by treating the edge of the ponds and the water surface. A randomized complete block design was used for all experiments with 200 mosquitoes released each day. Experiments were conducted in screened semi-field systems using insectary-reared An. gambiae s.s. Data were analysed by generalized estimating equations. Results An electric net operated at the highest spark box energy of a 400 volt direct current made the net spark, creating a crackling sound, a burst of light and a burning smell. This setting caught 64% less mosquitoes than a net powered by reduced voltage output that could neither be heard nor seen (odds ratio (OR 0.46; 95% confidence interval (CI 0.40-0.53, p Conclusion A square of four e-nets with yellow sticky boards as a collection device can be used for quantifying the numbers of mosquitoes approaching a small oviposition site. Shiny sticky surfaces attract gravid females possibly because they are visually mistaken as aquatic habitats. These materials might be developed further as gravid traps
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Abdulhakim A. El Maghrbi
2014-06-01
Full Text Available Alcoholic/acetone extracts of nine species of plants (Allium tuberosum, Apium leptophylum, Carica papaya, Cymbopogon citratus, Euphorbia cotinofolia, Melia azedarach, Ocimum canum, Ricinus communis and Tagetes erecta were tested in respect to their influence on the ovi-position behavior of the mosquito, Aedes fluviatilis and Culex quinquifasciatus in concentrations of 100, 10 and 1 mg/L. Three days after mosquito females had fed on blood of anesthetized mice and pigeon respectively, experimental and control dishes were placed into cages for 24 h then number of eggs laid in each dish was counted. Alcoholic/acetone extracts of C. papaya, C. citratus and T. erecta at 100 mg/L; E. cotinofolia and O. canum at 100 and 10 mg/L were proved to be repulsive for ovi-position of Ae. fluviatilis. On the other hand, acetone extracts of A. tuberosum and M. azederach at 100 and 10 mg/L; A. leptophyllum, O. canum, E. cotinofolia and R. communis at 100 mg/L produced same effect on ovi-position behavior of Ae. fluviatilis. Alcoholic extracts E. cotinofolia, R. communis (100 mg/L and M. azedarach (100 and 10 mg/L were attractive to Cx. quinquifasciatus. Five acetone extracts (A. tuberosum, A. leptophylum, C. papaya, C. Citrates and M. azedarach were repulsive for ovi-position at 100 mg/L. Acetone extract of A. tuberosum and M. azedarach at 10 and 1 mg/L and C. citratus at 10 mg/L maintained the same properties. Our results concluded that each plant extract has the potential to control ovi-position behavior of mosquito. The differences in obtained responses necessitate the adoption of deeper research to isolate the active principle of such plants for potential use in mosquito control program.
Fei, Minghui; Harvey, Jeffrey A; Yin, Yi; Gols, Rieta
2017-06-01
The effects of temporal variation in the quality of short-lived annual plants on oviposition preference and larval performance of insect herbivores has thus far received little attention. This study examines the effects of plant age on female oviposition preference and offspring performance in the large cabbage white butterfly Pieris brassicae. Adult female butterflies lay variable clusters of eggs on the underside of short-lived annual species in the family Brassicaceae, including the short-lived annuals Brassica nigra and Sinapis arvensis, which are important food plants for P. brassicae in The Netherlands. Here, we compared oviposition preference and larval performance of P. brassicae on three age classes (young, mature, and pre-senescing) of B. nigra and S. arvensis plants. Oviposition preference of P. brassicae declined with plant age in both plant species. Whereas larvae performed similarly on all three age classes in B. nigra, preference and performance were weakly correlated in S. arvensis. Analysis of primary (sugars and amino acids) and secondary (glucosinolates) chemistry in the plant shoots revealed that differences in their quality and quantity were more pronounced with respect to tissue type (leaves vs. flowers) than among different developmental stages of both plant species. Butterflies of P. brassicae may prefer younger and smaller plants for oviposition anticipating that future plant growth and size is optimally synchronized with the final larval instar, which contributes >80% of larval growth before pupation.
Kinjo, Hirotoshi; Kunimi, Yasuhisa; Ban, Takuya; Nakai, Madoka
2013-08-01
Drosophila suzukii (Matsumura) is an important pest of thin-skinned fruits including blueberry, raspberry, strawberry, and cherry. Blueberry was introduced into Japan in the 1950s, and severe economic losses attributable to D. suzukii were first reported in 2002. The objective of this study was to elucidate whether oviposition behavior varies among blueberry cultivars having different firmness of fruit. Fruit firmness in 12 cultivars of highbush blueberry (Vaccinium corymbosum L.) and rabbiteye blueberry (Vaccinium virgatum Aiton) was determined using a rheometer. More eggs tended to be laid in berries of cultivars possessing softer fruits than in those having firmer fruits. Choice tests, where one female was allowed to oviposit on blueberry fruits with different firmness, showed that softer fruits were more vulnerable to D. suzukii females than firmer fruits.
Influence of breeding site availability on the oviposition behaviour of Aedes aegypti
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Filipe Vieira Santos de Abreu
2015-08-01
Full Text Available Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16 was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches.
Influence of breeding site availability on the oviposition behaviour of Aedes aegypti
de Abreu, Filipe Vieira Santos; Morais, Maira Moreira; Ribeiro, Sérvio Pontes; Eiras, Álvaro Eduardo
2015-01-01
Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16) was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches. PMID:26154742
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El-Moursy, A.A.; Roushdy, H.M.; Abdel-Rahman, A.M.; Ali, G.M.
1986-01-01
The highest average egg of female dacus oleae was obtained when the texwax domes m.p. 121 degree C were used together with G.G.M. as oviposition medium, whereas the lowest mean was obtained when the paraffin mixture domes used. Using the texwax domes as a new oviposition medium was superior to either the G.G.M.or the paraffin mixture. The optimum percent hatchability was recorded when the G.G.M., texwax and paraffin mixture were used together as oviposition media, where the lowest percent hatchability was recorded when the G.G.M. was used only as oviposition medium. The longest oviposition duration was recorded when using the G.G.M. whereas the shortest duration occurred when the paraffin mixture was used. The highest rate of egg production was obtained by the twice mated females, whereas the lowest rate was obtained by the virgin ones. Also the percent hatchability recorded was higher in case of the twice-mated females than in females mated once
Honda, H; Bowers, W S
1996-01-01
The globemallow,Sphaeralcea emoryi Torrey, a plant native to Arizona was evaluated as a source of feeding or oviposition deterrents to the boll weevil,Anthonomus grandis Boheman. Feeding and oviposition responses of reproductive weevils to the flower buds and artificial diets spiked with dry powder or extracts of the globemallow buds were determined. Boll weevils were deterred from feeding and ovipositing in the flower buds unless the calyxes were removed. Male and virgin female weevils were discouraged from feeding as much as gravid weevils. Secondary chemicals in the flower buds served primarily as feeding deterrents but also prevented oviposition. The concentration of these chemicals was highest in the calyxes of the buds, and potent deterrent activity could be extracted from the calyxes with methanol. Boll weevils were able to perceive the deterrents by contact chemosensory organs on the antennae, maxillary palps and labial palps.
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Claudia M. Rauter
2012-01-01
Full Text Available Burying beetles (Nicrophorus spp. bury small carcasses to feed their larvae. Carcasses are a limited, high-quality resource and contests over carcasses become more frequent with increasing population density. Successful beetles kill eggs and larvae present on carcass. In response, females should accelerate oviposition, while offspring development should increase to minimize mortality. Both value of a carcass and frequency of contests decrease as larvae develop. If overproduction of offspring is an insurance against high mortality, females should reduce brood size as carcass value declines. Testing our predictions, we reared female burying beetles, Nicrophorus pustulatus, at high and low densities and compared oviposition and brood reduction. High-density females delayed oviposition, suggesting that high population density imposes nutritional and/or physiological stress. Females responded to the physiological constraints and the potentially high mortality rates of eggs and newly hatched larvae by lengthening oviposition period and changing brood reduction rate.
Kariyat, Rupesh R; Mauck, Kerry E; Balogh, Christopher M; Stephenson, Andrew G; Mescher, Mark C; De Moraes, Consuelo M
2013-04-22
Plant volatiles serve as key foraging and oviposition cues for insect herbivores as well as their natural enemies, but little is known about how genetic variation within plant populations influences volatile-mediated interactions among plants and insects. Here, we explore how inbred and outbred plants from three maternal families of the native weed horsenettle (Solanum carolinense) vary in the emission of volatile organic compounds during the dark phase of the photoperiod, and the effects of this variation on the oviposition preferences of Manduca sexta moths, whose larvae are specialist herbivores of Solanaceae. Compared with inbred plants, outbred plants consistently released more total volatiles at night and more individual compounds-including some previously reported to repel moths and attract predators. Female moths overwhelmingly chose to lay eggs on inbred (versus outbred) plants, and this preference persisted when olfactory cues were presented in the absence of visual and contact cues. These results are consistent with our previous findings that inbred plants recruit more herbivores and suffer greater herbivory under field conditions. Furthermore, they suggest that constitutive volatiles released during the dark portion of the photoperiod can convey accurate information about plant defence status (and/or other aspects of host plant quality) to foraging herbivores.
Bond, J Guillermo; Casas-Martínez, Mauricio; Quiroz-Martínez, Humberto; Novelo-Gutiérrez, Rodolfo; Marina, Carlos F; Ulloa, Armando; Orozco-Bonilla, Arnoldo; Muñoz, Miguel; Williams, Trevor
2014-01-22
The abundance, richness and diversity of mosquitoes and aquatic insects associated with their oviposition sites were surveyed along eight states of the Pacific coast of Mexico. Diversity was estimated using the Shannon index (H'), similarity measures and cluster analysis. Oviposition sites were sampled during 2-3 months per year, over a three year period. Field collected larvae and pupae were reared and identified to species following adult emergence. Aquatic insects present at oviposition sites were also collected, counted and identified to species or genus. In total, 15 genera and 74 species of mosquitoes were identified: Anopheles pseudopunctipennis, An. albimanus and Aedes aegypti were the most abundant and widely-distributed species, representing 47% of total mosquito individuals sampled. New species records for certain states are reported. Anopheline diversity was lowest in Sinaloa state (H' = 0.54) and highest in Chiapas (H' = 1.61) and Michoacán (H' = 1.56), whereas culicid diversity was lowest in Michoacán (H' = 1.93), Colima (H' = 1.95), Sinaloa (H' = 1.99) and Jalisco (H' = 2.01) and highest in Chiapas (H' = 2.66). In total, 10 orders, 57 families, 166 genera and 247 species of aquatic insects were identified in samples. Aquatic insect diversity was highest in Chiapas, Oaxaca and Michoacán (H' = 3.60-3.75). Mosquito larval/pupal abundance was not correlated with that of predatory Coleoptera and Hemiptera. This represents the first update on the diversity and geographic distribution of the mosquitoes and aquatic insects of Mexico in over five decades. This information has been cataloged in Mexico's National Biodiversity Information System (SNIB-CONABIO) for public inspection.
Dieng, Hamady; Satho, Tomomitsu; Suradi, Nur Farrahana Binti; Hakim, Hafijah; Abang, Fatimah; Aliasan, Nur Ezzati; Miake, Fumio; Zuharah, Wan Fatma; Kassim, Nur Faeza A; Majid, Abdul Hafiz A; Fadzly, Nik; Vargas, Ronald E Morales; Morales, Noppawan P; Noweg, Gabriel Tonga
2017-12-01
In dengue vector control, attempts to minimize or replace the use of pesticides have mostly involved use of predators, but success has been severely impeded by difficulties associated with financial and environmental costs, predator mass production, and persistence in target habitats. Visual deterrents have been used successfully to control animal pests, in some cases in an effort to replace pesticide use. Despite evidence that visual signals are crucial in site choice for egg deposition by dengue vectors, and that female mosquitoes respond to artificial predation, the role of predator intimidation as it affects the oviposition behavior of dengue vectors remains largely unexplored. Here, we examined the oviposition responses of Aedes aegypti exposed to various mosquito predator pictures. Gravid females were presented with equal opportunities to oviposit in two cups with predator images [Toxorhynchites splendens-TXI, Goldfish (Carassius auratus)-small (SFI) and large (LFI) and Tx. splendens+Goldfish-TXFI] and two others without pictures. Differences in egg deposition were examined between sites with and without these images. When given a chance to oviposit in cups with and without TXI, Ae. aegypti females were similarly attracted to both sites. When provided an opportunity to oviposit in cups displaying pictures of fish (SFI or LFI) and blank cups, egg deposition rates were much lower in the fish picture sites. Females showed a preference for blank cups over TXFI for egg deposition. They also equally avoided cups with pictures of fish, regardless of the size of the picture. Our results indicate that the presence of images of goldfish and their association with Tx. larvae significantly reduced egg deposition by Ae. aegypti, and this was not the case with the predatory larvae alone. The observations that the images of natural predators can repel gravid females of a dengue vector provide novel possibilities to develop effective and inexpensive alternative tools to
Oviposition behaviour of the soil mite Pergamasus brevicornis (Acari: Parasitidae).
Marquardt, Tomasz; Faleńczyk-Koziróg, Katarzyna; Kaczmarek, Sławomir
2013-07-01
We observed the oviposition behaviour of the soil mite Pergamasus brevicornis Berlese (Acari: Parasitidae) using continuous video-monitoring. Oviposition consisted of six sequential phases. The first phase (I) involved inspection of the substrate. In the second phase (II) there were rhythmic movements of the first pair of legs and slight reciprocating movements of the body. The third (III) was a resting phase. In the fourth phase (IV) the gnathosoma was lowered and the body was raised. In the next phase (V) there were two sub-phases. During the first (Va), the female held the egg below the gnathosoma. In the second sub-phase (Vb), the gnathosoma moved up holding the egg, which was then placed on the substrate. The last phase (VI) involved intense 'cleaning' movements of the chelicerae and palps. During Va a protective external eggshell structure is gradually formed, involving a phase where the egg shell is sticky. After moving the egg to the substrate, the female freed her palps and chelicerae from the sticky egg shell and cleaned her gnathosomal appendages. Phases II-V took on average 207 ± 69 s.
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Thomas Bawin
2014-11-01
Full Text Available The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae, is a devastating pest that develops principally on solanaceous plants throughout South and Central America and Europe. In this study, we tested the influence of three levels of T. absoluta infestations on the attraction and oviposition preference of adult T. absoluta. Three infestation levels (i.e., non-infested plants, plants infested with 10 T. absoluta larvae, and plants infested with 20 T. absoluta larvae were presented by pairs in a flying tunnel to groups of T. absoluta adults. We found no differences in terms of adult attraction for either level of infestations. However, female oviposition choice is influenced by larvae density on tomato plants. We discuss the underlying mechanisms and propose recommendations for further research.
Oviposition and egg quality traits of dwarf and naked neck layers ...
African Journals Online (AJOL)
Oviposition and egg quality traits were studied in dwarf and naked neck layers in Maputo (Mozambique) during a 28-d period at 35 weeks of age. Birds were caged individually in a laying house with natural light and ventilation. Average daylight length during the study was 11.2 hr and minimum and maximum temperature ...
2015-03-01
COMPARISON OF BG-SENTINELH TRAP AND OVIPOSITION CUPS FOR AEDES AEGYPTI AND AEDES ALBOPICTUS SURVEILLANCE IN JACKSONVILLE, FLORIDA, USA JENNIFER A...trap and oviposition cups (OCs) have both proven effective in the surveillance of Aedes species. This study aimed to determine which of the 2 traps could...best characterize the relative population sizes of Aedes albopictus and Aedes aegypti in an urban section of Jacksonville, FL. Until 1986, Ae
Bezzar-Bendjazia, Radia; Kilani-Morakchi, Samira; Aribi, Nadia
2016-10-01
Azadirachtin, a biorational insecticide, is one of the prominent biopesticide commercialized today and represent an alternative to conventional insecticides. The current study examined the lethal and sublethal effects of azadirachtin on Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae) as biological model. Various doses ranging from 0.1 to 2μg were applied topically on early third instar larvae and the cumulative mortality of immature stage was determined. In second series of experiments, azadirachtin was applied at its LD 25 (0.28μg) and LD 50 (0.67μg) and evaluated on fitness (development duration, fecundity, adult survival) and oviposition site preference with and without choice. Results showed that azadirachtin increased significantly at the two tested doses the duration of larval and pupal development. Moreover, azadirachtin treatment reduced significantly adult's survival of both sex as compared to control. In addition, azadirachtin affected fecundity of flies by a significant reduction of the number of eggs laid. Finally results showed that females present clear preference for oviposition in control medium. Pre-imaginal exposure (L3) to azadirachtin increased aversion to this substance suggesting a memorability of the learned avoidance. The results provide some evidence that larval exposure to azadirachtin altered adult oviposition preference as well as major fitness traits of D. melanogaster. Theses finding may reinforce behavioural avoidance of azadirachtin and contribute as repellent strategies in integrated pest management programmes. Copyright © 2016 Elsevier B.V. All rights reserved.
Multi-spatial analysis of aeolian dune-field patterns
Ewing, Ryan C.; McDonald, George D.; Hayes, Alex G.
2015-07-01
Aeolian dune-fields are composed of different spatial scales of bedform patterns that respond to changes in environmental boundary conditions over a wide range of time scales. This study examines how variations in spatial scales of dune and ripple patterns found within dune fields are used in environmental reconstructions on Earth, Mars and Titan. Within a single bedform type, different spatial scales of bedforms emerge as a pattern evolves from an initial state into a well-organized pattern, such as with the transition from protodunes to dunes. Additionally, different types of bedforms, such as ripples, coarse-grained ripples and dunes, coexist at different spatial scales within a dune-field. Analysis of dune-field patterns at the intersection of different scales and types of bedforms at different stages of development provides a more comprehensive record of sediment supply and wind regime than analysis of a single scale and type of bedform. Interpretations of environmental conditions from any scale of bedform, however, are limited to environmental signals associated with the response time of that bedform. Large-scale dune-field patterns integrate signals over long-term climate cycles and reveal little about short-term variations in wind or sediment supply. Wind ripples respond instantly to changing conditions, but reveal little about longer-term variations in wind or sediment supply. Recognizing the response time scales across different spatial scales of bedforms maximizes environmental interpretations from dune-field patterns.
Barros, Eduardo M; Torres, Jorge B; Bueno, Adeney F
2010-01-01
The host selection for oviposition by Spodoptera frugiperda (J.E. Smith) among corn, millet, cotton and soybean, and its relationship with the biological characteristics were investigated. Free and non-choice tests for oviposition using plots containing five plants each, from each host in plastic greenhouse, resulted in similar oviposition preference among the host plants. In addition, selected biological characteristics of S. frugiperda were determined in the laboratory with larvae feeding on host leaves, and the combination of leaf and cotton boll. Neonate larvae exhibited low success of colonization on cotton boll compared to the leaves of all other hosts. Spodoptera frugiperda fed only on cotton bolls exhibited longer larval and pupal development, and longer adult life span; however with similar egg production. Larvae fed cotton leaves during six days and then transferred to cotton bolls, however, exhibited development and reproduction similar to those reared on corn or only on cotton leaves. Therefore, the variations on immature stages of S. frugiperda were not related with host selection for oviposition which was similar among the studied hosts. Based on our data, the millet as a winter, rotational, and cover crop is a potential host for S. frugiperda, while leaves and cotton bolls were diets of intermediate suitability as compared to corn and soybean leaves.
Blaul, Birgit; Ruther, Joachim
2011-11-07
Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by (13)C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons.
Basukriadi, Adi; Wilkins, Richard M
2014-01-01
An extract of a rotenone-containing plant yam bean, Pachyrhizus erosus (L.) Urban, seeds was tested against the diamondback moth, Plutella xylostella (L.) in a greenhouse to determine its potential as an oviposition deterrent and compared with coumarin and rutin, known as diamondback moth oviposition deterrent compounds, rotenone, and an extract of Peruvian cube root, at a concentration of 0.5% (w/v). Oviposition deterrent index (ODI) was used to determine effects of extracts or compounds in inhibiting oviposition of diamondback moth. Coumarin showed a stronger deterrent effect than the yam bean seed extract with a higher ODI value. On the contrary, rotenone, rutin, and the cube root extract, containing 6.7% (w/w) of rotenone, showed no significant deterrent effects having low or negative ODI values, suggesting that the deterrent effect of the yam bean seed extract is not due to rotenone content of the yam bean seeds. The extract of yam bean seed and coumarin partially deterred the moth from laying eggs on treated leaves in a concentration-dependent manner. The effective concentration for 50% deterrency of coumarin and the yam bean seed extract were 0.11 and 0.83% (w/v), respectively. However, the yam bean seed extract showed a residual deterrent effect on the moth even at 3 d after the treatment and is probably because of its low volatile nature. A long-term deterrency of the yam bean seed extract is an advantage over coumarins. Both the yam bean seed extract and coumarin deterred diamondback moth from laying eggs in total darkness, indicating their nonvisual deterrent effect. This made the extract an effective deterrence to diamondback moth in light and in darkness. To conclude, this study revealed the potential of the crude extract of the yam bean seed to prevent diamondback moth from ovipositing on its plant host. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.
Female grasshoppers can affect the fitness of their offspring through their selection of oviposition sites. Successful embryological development depends on suitable temperature and moisture levels, factors which may vary considerably on a fine scale in natural environments where grasshoppers occur. ...
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Yoshioka Miho
2012-10-01
Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding
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Fontellas-Brandalha, Tania M.L.; Zucoloto, Fernando S. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Biologia]. E-mail: zucoloto@ffclrp.usp.br
2004-09-15
Few works have studied in detail the types of nutrients associated to hosts which are attractive to females of Anastrepha obliqua (Macquart) and influence the choice of the oviposition site. The relationship of the males in the physiology and in the behavior of those females has also been scarcely studied and some ecological relationships seem to be quite important for the knowledge of this species' biology. Our objective in this study was to evaluate the discriminatory behavior of A. obliqua between oviposition sites containing different nutrients. The presence of the male and the nutritional status of the female were also considered in this work. Two experiments were developed: in the first, the preference of A. obliqua females between artificial oviposition substrates was evaluated; in the second, females were submitted to two types of artificial oviposition substrates in the presence and in the absence of males and were fed either on a poor diet or on an adequate diet concerning sucrose concentration. In the first experiment, A. obliqua showed higher preference for substrates containing brewer's yeast and sucrose. Substrate containing only yeast was the second most accepted. Offspring development and adult feeding may have determined the choice for the substrate containing brewer's yeast and sucrose. In addition, the presence of protein in the brewer's yeast may indicate nutritional quality to the females in a more accurate way than the sucrose. In the second experiment, the brewer's yeast was the most accepted by the females. The male absence was also an important factor in the selection of hosts and in the egg production of A. obliqua. (author)
International Nuclear Information System (INIS)
Fontellas-Brandalha, Tania M.L.; Zucoloto, Fernando S.
2004-01-01
Few works have studied in detail the types of nutrients associated to hosts which are attractive to females of Anastrepha obliqua (Macquart) and influence the choice of the oviposition site. The relationship of the males in the physiology and in the behavior of those females has also been scarcely studied and some ecological relationships seem to be quite important for the knowledge of this species' biology. Our objective in this study was to evaluate the discriminatory behavior of A. obliqua between oviposition sites containing different nutrients. The presence of the male and the nutritional status of the female were also considered in this work. Two experiments were developed: in the first, the preference of A. obliqua females between artificial oviposition substrates was evaluated; in the second, females were submitted to two types of artificial oviposition substrates in the presence and in the absence of males and were fed either on a poor diet or on an adequate diet concerning sucrose concentration. In the first experiment, A. obliqua showed higher preference for substrates containing brewer's yeast and sucrose. Substrate containing only yeast was the second most accepted. Offspring development and adult feeding may have determined the choice for the substrate containing brewer's yeast and sucrose. In addition, the presence of protein in the brewer's yeast may indicate nutritional quality to the females in a more accurate way than the sucrose. In the second experiment, the brewer's yeast was the most accepted by the females. The male absence was also an important factor in the selection of hosts and in the egg production of A. obliqua. (author)
McPhatter, Lee P; Debboun, Mustapha
2009-12-01
Field experiments were conducted on the Fort Sam Houston Military Reservation, San Antonio, TX, in fall 2008 to observe the attractiveness of selected botanical infusions to ovipositing female mosquitoes. The following infusions were tested in Centers for Disease Control and Prevention gravid traps: Bermuda grass (Cynodon dactylon), oak leaf (Quercus virginiana), acacia leaf (Acacia schaffneri), rabbit chow (alfalfa pellets), and algae (Spirogyra sp.). Four (Bermuda, acacia, oak, and algae) of the 5 infusions were effective in collecting Culex quinquefasciatus, Cx. nigripalpus, and Cx. erraticus. Of the 4 infusions, Bermuda collected the greatest number of the mosquitoes sampled. Female Aedes albopictus mosquitoes were collected in moderate numbers during this study.
Mahat, N A; Zafarina, Z; Jayaprakash, P T
2009-11-20
The influence of rain and malathion on the initial oviposition as well as development of blowfly species infesting rabbit carcasses decomposing in sunlit and shaded habitats were studied over a period of 1 year in Kelantan, Malaysia. Chrysomya megacephala (Fabricius) was the most dominant species that infested the carcasses, followed by Chrysomya rufifacies (Macquart). In general, rain, depending on its intensity, delayed initial oviposition by 1-2 days and prolonged the pupation period by 1-3 days. The presence of malathion in the carcasses delayed initial oviposition by 1-3 days and prolonged the pupation period by 2-3 days. These findings deserve consideration while estimating postmortem interval since rain is a commonplace occurrence in Malaysia and malathion is one of the common poisons as an agent for choice to commit suicide.
Different levels of shade on population of grasshoppers and its oviposition preference on heliconias
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Ana Cristina Bittar
2018-02-01
Full Text Available ABSTRACT: Grasshoppers of the families Acrididae and Romaleidae (Orthoptera are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil, to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata ‘Golden Torch’ in the subplot, with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae. An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity.
Hall, David G; Wenninger, Erik J; Hentz, Matthew G
2011-01-01
This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 °C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 °C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 °C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 °C.
Synchronized oviposition triggered by migratory flight intensifies larval outbreaks of beet webworm.
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Yun Xia Cheng
Full Text Available Identifying the reproductive consequences of insect migration is critical to understanding its ecological and evolutionary significance. However, many empirical studies are seemingly contradictory, making recognition of unifying themes elusive and controversial. The beet webworm, Loxostege sticticalis L. is a long-range migratory pest of many crops in the northern temperate zone from 36 °N to 55 °N, with larval populations often exploding in regions receiving immigrants. In laboratory experiments, we examined (i the reproductive costs of migratory flight by tethered flight, and (ii the reproductive traits contributing to larval outbreaks of immigrant populations. Our results suggest that the beet webworm does not initiate migratory flight until the 2nd or 3rd night after emergence. Preoviposition period, lifetime fecundity, mating capacity, and egg hatch rate for adults that experienced prolonged flight after the 2nd night did not differ significantly from unflown moths, suggesting these traits are irrelevant to the severity of beet webworm outbreaks after migration. However, the period of first oviposition, a novel parameter developed in this paper measuring synchrony of first egg-laying by cohorts of post-migratory females, for moths flown on d 3 and 5 of adulthood was shorter than that of unflown moths, indicating a tightened time-window for onset of oviposition after migration. The resulting synchrony of egg-laying will serve to increase egg and subsequent larval densities. A dense population offers potential selective advantages to the individual larvae comprising it, whereas the effect from the human standpoint is intensification of damage by an outbreak population. The strategy of synchronized oviposition may be common in other migratory insect pests, such as locust and armyworm species, and warrants further study.
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E.A. Elhag
1999-06-01
Full Text Available Methanol and diethyl ether extracts of Harmal, Rhazya stricta Decne.; neem seed kernels, Azadirachta indica A.Juss; cloves, Syzygeum aromarticum (L.; citrus peel and Ramram, Heliotropium bacciferum (Forssk- were evaluated for their deterrence to oviposition by Callosobruchus maculatus (F. on chickpeas in choice tests. Both extracts of all materials significantly reduced oviposition on treated seeds. Maximum deterrent effects (91.8% were obtained in the neem seed methanol extract at 0.5% concentration, citrus peel O. l% ether extract (90.9%, R stricta 0.5% methanol extract (83.9%, and clove 0. 1% ether extract (80.0%. Methanol extracts of neem seeds and R. stricta evoked higher deterrent effects than their etherial extracts, whereas the responses for cloves and citrus peel were more pronounced in their ether extracts. H. bacirferum % deterrency due to both types of extracts were practically identical. The results encourage future incorporation of such plant extracts as ovipositional deterrents in stored-product lPM programmes.
The tale of two buckets and associated containers: impact on aedes albopictus oviposition
Aedes albopictus is an invasive species. Its oviposition behavior is the subject of several projects in our research unit. The main emphasis of this presentation is a study which utilizes two five gallon buckets, one heated and one with ambient temperature. The heat is provided by an aquarium hea...
Rangeland fire is a common naturally occurring event and management tool, with the amount and structure of biomass controlling transfer of heat belowground. Temperatures grasshopper eggs are exposed to during rangeland fires are mediated by species specific oviposition traits. This experiment examin...
The effect of relatedness on the response of Adalia bipunctata L. to oviposition deterring cues
Czech Academy of Sciences Publication Activity Database
Martini, X.; Dixon, Anthony F. G.; Hemptinne, J. L.
2013-01-01
Roč. 103, č. 1 (2013), s. 14-19 ISSN 0007-4853 Institutional support: RVO:67179843 Keywords : Coccinellidae * relatedness * kin * larval tracks * oviposition deterring pheromone Subject RIV: EH - Ecology, Behaviour Impact factor: 1.895, year: 2013
Oviposition of Quesada gigas in weed no hostess: implication in pest management
Directory of Open Access Journals (Sweden)
Douglas Henrique Bottura Maccagnan
Full Text Available ABSTRACT: This study recorded the choice of dry plant of Conyza spp as oviposition site by cicada Quesada gigas (Olivier, 1790. We presented issues of natural history of the cicadas that indicate the inability of immatures to complete life cycle in this species of plant. Some implications on cultures where Q. gigas has economic importance are also discussed.
Avoidance of host resistance in the oviposition-site preferences of rose bitterling
Czech Academy of Sciences Publication Activity Database
Rouchet, Romain; Smith, Carl; Liu, H.; Methling, Caroline; Douda, K.; Yu, D.; Tang, Q.; Reichard, Martin
2017-01-01
Roč. 31, č. 5 (2017), s. 769-783 ISSN 0269-7653 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : Brood parasitism * Coevolutionary dynamic * Egg ejection * Host selection * Oviposition choice * Parasite specialisation Subject RIV: EG - Zoology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 1.818, year: 2016
Spiking patterns of a hippocampus model in electric fields
International Nuclear Information System (INIS)
Men Cong; Wang Jiang; Qin Ying-Mei; Wei Xi-Le; Deng Bin; Che Yan-Qiu
2011-01-01
We develop a model of CA3 neurons embedded in a resistive array to mimic the effects of electric fields from a new perspective. Effects of DC and sinusoidal electric fields on firing patterns in CA3 neurons are investigated in this study. The firing patterns can be switched from no firing pattern to burst or from burst to fast periodic firing pattern with the increase of DC electric field intensity. It is also found that the firing activities are sensitive to the frequency and amplitude of the sinusoidal electric field. Different phase-locking states and chaotic firing regions are observed in the parameter space of frequency and amplitude. These findings are qualitatively in accordance with the results of relevant experimental and numerical studies. It is implied that the external or endogenous electric field can modulate the neural code in the brain. Furthermore, it is helpful to develop control strategies based on electric fields to control neural diseases such as epilepsy. (interdisciplinary physics and related areas of science and technology)
Trickle-down boundary conditions in aeolian dune-field pattern formation
Ewing, R. C.; Kocurek, G.
2015-12-01
One the one hand, wind-blown dune-field patterns emerge within the overarching boundary conditions of climate, tectonics and eustasy implying the presence of these signals in the aeolian geomorphic and stratigraphic record. On the other hand, dune-field patterns are a poster-child of self-organization, in which autogenic processes give rise to patterned landscapes despite remarkable differences in the geologic setting (i.e., Earth, Mars and Titan). How important are climate, tectonics and eustasy in aeolian dune field pattern formation? Here we develop the hypothesis that, in terms of pattern development, dune fields evolve largely independent of the direct influence of 'system-scale' boundary conditions, such as climate, tectonics and eustasy. Rather, these boundary conditions set the stage for smaller-scale, faster-evolving 'event-scale' boundary conditions. This 'trickle-down' effect, in which system-scale boundary conditions indirectly influence the event scale boundary conditions provides the uniqueness and richness of dune-field patterned landscapes. The trickle-down effect means that the architecture of the stratigraphic record of dune-field pattern formation archives boundary conditions, which are spatially and temporally removed from the overarching geologic setting. In contrast, the presence of an aeolian stratigraphic record itself, reflects changes in system-scale boundary conditions that drive accumulation and preservation of aeolian strata.
Deceptive female oviposition behaviour elicits male ejaculation in the European bitterling
Czech Academy of Sciences Publication Activity Database
Smith, C.; Zhu, Y.; Liu, H.; Reichard, Martin
2007-01-01
Roč. 71, č. 6 (2007), s. 1841-1846 ISSN 0022-1112 R&D Projects: GA AV ČR KJB600930501 Grant - others:The Leverhulme Trust(GB) NSFC 30470237 Institutional research plan: CEZ:AV0Z60930519 Keywords : mating tactics * pre-oviposition ejaculation * signal evolution * sneaking sperm competition Subject RIV: EH - Ecology, Behaviour Impact factor: 1.404, year: 2007 http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1095-8649.2007.01624.x
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Christer Björkman
2011-01-01
Full Text Available It is anticipated that extreme population events, such as extinctions and outbreaks, will become more frequent as a consequence of climate change. To evaluate the increased probability of such events, it is crucial to understand the mechanisms involved. Variation between individuals in their response to climatic factors is an important consideration, especially if microevolution is expected to change the composition of populations.Here we present data of a willow leaf beetle species, showing high variation among individuals in oviposition rate at a high temperature (20 °C. It is particularly noteworthy that not all individuals responded to changes in temperature; individuals laying few eggs at 20 °C continued to do so when transferred to 12 °C, whereas individuals that laid many eggs at 20 °C reduced their oviposition and laid the same number of eggs as the others when transferred to 12 °C. When transferred back to 20 °C most individuals reverted to their original oviposition rate. Thus, high variation among individuals was only observed at the higher temperature. Using a simple population model and based on regional climate change scenarios we show that the probability of outbreaks increases if there is a realistic increase in the number of warm summers. The probability of outbreaks also increased with increasing heritability of the ability to respond to increased temperature.If climate becomes warmer and there is latent variation among individuals in their temperature response, the probability for outbreaks may increase. However, the likelihood for microevolution to play a role may be low. This conclusion is based on the fact that it has been difficult to show that microevolution affect the probability for extinctions. Our results highlight the urge for cautiousness when predicting the future concerning probabilities for extreme population events.
Control and near-field detection of surface plasmon interference patterns.
Dvořák, Petr; Neuman, Tomáš; Břínek, Lukáš; Šamořil, Tomáš; Kalousek, Radek; Dub, Petr; Varga, Peter; Šikola, Tomáš
2013-06-12
The tailoring of electromagnetic near-field properties is the central task in the field of nanophotonics. In addition to 2D optics for optical nanocircuits, confined and enhanced electric fields are utilized in detection and sensing, photovoltaics, spatially localized spectroscopy (nanoimaging), as well as in nanolithography and nanomanipulation. For practical purposes, it is necessary to develop easy-to-use methods for controlling the electromagnetic near-field distribution. By imaging optical near-fields using a scanning near-field optical microscope, we demonstrate that surface plasmon polaritons propagating from slits along the metal-dielectric interface form tunable interference patterns. We present a simple way how to control the resulting interference patterns both by variation of the angle between two slits and, for a fixed slit geometry, by a proper combination of laser beam polarization and inhomogeneous far-field illumination of the structure. Thus the modulation period of interference patterns has become adjustable and new variable patterns consisting of stripelike and dotlike motifs have been achieved, respectively.
Prathibha, K P; Raghavendra, B S; Vijayan, V A
2014-05-01
In mosquito control programs, insecticides of botanical origin have the potential to eliminate eggs, larvae, and adults. So, the larvicidal, ovicidal, and oviposition-deterrent activities of petroleum ether and ethyl acetate extracts of the leaves of Eugenia jambolana, Solidago canadensis, Euodia ridleyi, and Spilanthes mauritiana were assayed against the three vector mosquito species, namely Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The larval bioassay was conducted following the World Health Organization method. The maximum larval mortality was found with ethyl acetate extract of S. mauritiana against the larvae of A. stephensi, A. aegypti, and C. quinquefasciatus with LC50 values of 11.51, 28.1, 14.10 ppm, respectively. The mean percent hatchability of the ovicidal activity was observed at 48-h post-treatment. The percent hatchability was found to be inversely proportional to the concentration of the extract and directly proportional to the number of eggs. The flower head extract of S. mauritiana gave 100% mortality followed by E. ridleyi, S. canadensis, and E. jambolana against the eggs of the three mosquito vectors. For oviposition-deterrent effect, out of the five concentrations tested (20, 40, 60, 80, and 100 ppm), the concentration of 100 ppm showed a significant egg laying-deterrent capacity. The oviposition activity index value of E. jambolana, E. ridleyi, S. canadensis, and S. mauritiana against A. aegypti, A. stephensi, C. quinquefasciatus at 100 ppm were -0.71, -0.71, -0.90, -0.93, -0.85, -0.91, -1, -1, -0.71, -0.85, -1, and -1, respectively. These results suggest that the leaf/flower extracts of certain local plants have the potential to be developed as possible eco-friendly means for the control of mosquitoes.
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Rayane Cristine Santos da Silva
Full Text Available Aedes aegypti is responsible for the transmission of dengue, a disease that infects millions of people each year. Although essential oils are well recognized as sources of compounds with repellent and larvicidal activities against the dengue mosquito, much less is known about their oviposition deterrent effects. Commiphora leptophloeos, a tree native to South America, has important pharmacological properties, but the chemical profile and applicability of its essential oil in controlling the spread of the dengue mosquito have not been investigated. The aim of this study was to determine the composition of C. leptophloeos leaf oil and to evaluate its larvicidal and oviposition deterrent effects against A. aegypti. Fifty-five components of the essential oil were detected by gas chromatography (GC-mass spectrometry, with α-phellandrene (26.3%, (E-caryophyllene (18.0% and β-phellandrene (12.9% identified as the major constituents. Bioassays showed that the oil exhibited strong oviposition deterrent effects against A. aegypti at concentrations between 25 and 100 ppm, and possessed good larvicidal activity (LC50 = 99.4 ppm. Analysis of the oil by GC coupled with electroantennographic detection established that seven constituents could trigger antennal depolarization in A. aegypti gravid females. Two of these components, namely (E-caryophyllene and α-humulene, were present in substantial proportions in the oil, and oviposition deterrence assays confirmed that both were significantly active at concentrations equivalent to those present in the oil. It is concluded that these sesquiterpenes are responsible, at least in part, for the deterrent effect of the oil. The oviposition deterrent activity of the leaf oil of C. leptophloeos is one of the most potent reported so far, suggesting that it could represent an interesting alternative to synthetic insecticides. The results of this study highlight the importance of integrating chemical and
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Stefanescu, C.
2006-06-01
Full Text Available Iphiclides podalirius is an oligophagous butterfly which feeds on plants of the Rosaceae family. In 2002 and 2005 in NE Spain, we recorded for the first time oviposition on two alien plant species, Cotoneaster franchetii and Spiraea cantoniensis. To ascertain if this unusual behaviour represents a broadening of host range or, alternatively, an oviposition mistake, larval performance on the new plants was investigated in the laboratory and compared with performance on the most common host plants used in the study area. Although larval performance on common hosts differed to some extent, the use of a wide range of plants of different quality at population level may in fact respond to the so-called “spreading of risk” strategy in variable environments. On the other hand, larval performance and survival to adulthood were so low on the two new hosts that our observations probably represent a case of maladaptive oviposition behaviour. This may be due to an evolutionary lag between the newly introduced plants and the insect, although other possible explanations are also taken into account.
International Nuclear Information System (INIS)
Honorio, Nildimar A.
2007-01-01
Toxorhynchites guadeloupensis (Dyar and Knab), a poorly known mosquito species, was observed preying upon Aedes aegypti (L.) larvae, in an oviposition trap placed for routine dengue entomological surveillance, during 2003-2004 in the urban area of Boa Vista, Roraima, Brazil. This is the first report for Tx. guadeloupensis using Ae. aegypti oviposition traps as breeding places. This finding may have important consequences in the epidemiology and local dengue control since Ae. aegypti density is a basic variable in dengue prediction. Whether predation of Ae aegypti by Tx. guadeloupensis in the Amazon is of significance, is a question to be examined. Also, larval predation may be a cause for underestimation of the actual Ae aegypti numbers. Together these hypotheses need to be better investigated as they are directly related to dengue epidemiology, to the success of any outbreak prediction and surveillance program. (author)
Energy Technology Data Exchange (ETDEWEB)
Honorio, Nildimar A. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept. de Entomologia. Lab. de Transmissores de Hematozoarios; Barros, Fabio S.M. de [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil). Centro de Ciencias Biologicas e da Saude. Nucleo Avancado de Vetores; Tsouris, Pantelis; Rosa-Freitas, Maria G. [Freitas and Tsouris Consultants, Spata-Attikis (Greece)]. E-mail: maria@freitas-tsouris.com
2007-09-15
Toxorhynchites guadeloupensis (Dyar and Knab), a poorly known mosquito species, was observed preying upon Aedes aegypti (L.) larvae, in an oviposition trap placed for routine dengue entomological surveillance, during 2003-2004 in the urban area of Boa Vista, Roraima, Brazil. This is the first report for Tx. guadeloupensis using Ae. aegypti oviposition traps as breeding places. This finding may have important consequences in the epidemiology and local dengue control since Ae. aegypti density is a basic variable in dengue prediction. Whether predation of Ae aegypti by Tx. guadeloupensis in the Amazon is of significance, is a question to be examined. Also, larval predation may be a cause for underestimation of the actual Ae aegypti numbers. Together these hypotheses need to be better investigated as they are directly related to dengue epidemiology, to the success of any outbreak prediction and surveillance program. (author)
Masanza, M.; Gold, C.S.; Huis, van A.; Ragama, P.E.
2005-01-01
The effect of covering post-harvest banana stumps with soil on banana weevil Cosmopolites sordidus (Germar) oviposition levels was investigated at three locations, Sendusu, Kawanda Agricultural Research Institute (KARI) and Ntungamo district of southwestern Uganda. In the first experiment
Bos, M.; Boerema, A.
1981-01-01
Oviposition-site preferences (O.S.P.) have been investigated in females of six sibling species of the Drosophila melanogaster subgroup. O.S.P. were determined for standard food components and yeast genotypes. Females of all species showed a strong preference for complete medium and avoidance of pure
Rännbäck, Linda-Marie; Cotes, Belen; Anderson, Peter; Rämert, Birgitta; Meyling, Nicolai V
2015-01-01
Biological control of pests in agroecosystems could be enhanced by combining multiple natural enemies. However, this approach might also compromise the control efficacy through intraguild predation (IGP) among the natural enemies. Parasitoids may be able to avoid the risk of unidirectional IGP posed by entomopathogenic fungi through selective oviposition behavior during host foraging. Trybliographa rapae is a larval parasitoid of the cabbage root fly, Delia radicum. Here we evaluated the susceptibility of D. radicum and T. rapae to two species of generalist entomopathogenic fungi, Metarhizium brunneum isolate KVL 04-57 and Beauveria bassiana isolate KVL 03-90. Furthermore, T. rapae oviposition behavior was assessed in the presence of these entomopathogenic fungi either as infected hosts or as infective propagules in the environment. Both fungi were pathogenic to D. radicum larvae and T. rapae adults, but with variable virulence. When host patches were inoculated with M. brunneum conidia in a no-choice situation, more eggs were laid by T. rapae in hosts of those patches compared to control and B. bassiana treated patches. Females that later succumbed to mycosis from either fungus laid significantly more eggs than non-mycosed females, indicating that resources were allocated to increased oviposition due to perceived decreased life expectancy. When presented with a choice between healthy and fungal infected hosts, T. rapae females laid more eggs in healthy larvae than in M. brunneum infected larvae. This was less pronounced for B. bassiana. Based on our results we propose that T. rapae can perceive and react towards IGP risk posed by M. brunneum but not B. bassiana to the foraging female herself and her offspring. Thus, M. brunneum has the potential to be used for biological control against D. radicum with a limited risk to T. rapae populations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
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Wiwin Setiawati
2011-04-01
Full Text Available The fruit borer (Helicoverpa armigera Hubner is one of the key pests of chili pepper in Indonesia. Yield loss due to this insect pest may reach up to 60%. Chemical treatment for con-trolling this insect pest is ineffective and eventually leads to environmental pollution. More environmentally safe insecticides are developed based on natural plant ingredients as their active compound such as essential oils. This study aimed to assess the potential of citronella oil for managing H. armigera on chili pepper. The experiments were conducted at the Indonesian Vegetables Research Institute from April 2009 to March 2010 and in Cirebon, West Java from November 2009 to March 2010. A field experiment was designed in a randomized complete block design with five treatments and replicated five times. Citronella oil was extracted by steam distillation from Cymbo-pogon nardus. The oil was then chemically characterized by using GC-MS and its efficacy (ovicidal and feeding deterrent against H. armigera was tested both in laboratory and field conditions. The GC-MS result showed that major chemical compounds of the citronella oil used were citronella (35.97%, nerol (17.28%, citronellol (10.03%, geranyle acetate (4.44%, elemol (4.38%, limonene (3.98%, and citronnellyle acetate (3.51%. The laboratory experiment revealed that the highest concentration (4,000 ppm of citronella oil reduced egg laying by 53-66%. Ovicidal activity was concentration dependent, and egg hatchability decreased by 15-95% compared to control. The field experiment showed that treatment of citronella oil at 2.0 mL L-1 significantly reduced fruit damage by H. armigera similar to the plots treated with spinosad at the recommended dose (60 g ai ha-1. Application of citronella oil significantly reduced fruit damage by 72% and increased quality of the chili pepper. Because oviposition and feeding deterrent properties are key factors in controlling the pest, therefore this study revealed that
Energy Technology Data Exchange (ETDEWEB)
Vendramim, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: jdvendra@esalq.usp.br; Souza, Antonio P. de [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Morfofisiologia. Lab. de Anatomia Humana]. E-mail: apsouza@nin.ufms.br; Ongarelli, Maria das G. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Lab. de Fisiologia e Bioquimica Pos-Colheita]. E-mail: mgong@esalq.usp.br
2009-01-15
The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)
Fresh market sweet corn produced in Florida is threatened by larval damage by Euxesta stigmatias Loew, E. eluta Loew, and Chaetopsis massyla Walker (Diptera: Ulidiidae) that renders ears unmarketable. No standard lure exists for monitoring these pests. Oviposition and attraction bioassays were desig...
Learning to Recognize Patterns: Changes in the Visual Field with Familiarity
Bebko, James M.; Uchikawa, Keiji; Saida, Shinya; Ikeda, Mitsuo
1995-01-01
Two studies were conducted to investigate changes which take place in the visual information processing of novel stimuli as they become familiar. Japanese writing characters (Hiragana and Kanji) which were unfamiliar to two native English speaking subjects were presented using a moving window technique to restrict their visual fields. Study time for visual recognition was recorded across repeated sessions, and with varying visual field restrictions. The critical visual field was defined as the size of the visual field beyond which further increases did not improve the speed of recognition performance. In the first study, when the Hiragana patterns were novel, subjects needed to see about half of the entire pattern simultaneously to maintain optimal performance. However, the critical visual field size decreased as familiarity with the patterns increased. These results were replicated in the second study with more complex Kanji characters. In addition, the critical field size decreased as pattern complexity decreased. We propose a three component model of pattern perception. In the first stage a representation of the stimulus must be constructed by the subject, and restricting of the visual field interferes dramatically with this component when stimuli are unfamiliar. With increased familiarity, subjects become able to reconstruct a previous representation from very small, unique segments of the pattern, analogous to the informativeness areas hypothesized by Loftus and Mackworth [J. Exp. Psychol., 4 (1978) 565].
Electrophoretic deposition and field emission properties of patterned carbon nanotubes
International Nuclear Information System (INIS)
Zhao Haifeng; Song Hang; Li Zhiming; Yuan Guang; Jin Yixin
2005-01-01
Patterned carbon nanotubes on silicon substrates were obtained using electrophoretic method. The carbon nanotubes migrated towards the patterned silicon electrode in the electrophoresis suspension under the applied voltage. The carbon nanotubes arrays adhered well on the silicon substrates. The surface images of carbon nanotubes were observed by scanning electron microscopy. The field emission properties of the patterned carbon nanotubes were tested in a diode structure under a vacuum pressure below 5 x 10 -4 Pa. The measured emission area was about 1.0 mm 2 . The emission current density up to 30 mA/cm 2 at an electric field of 8 V/μm has been obtained. The deposition of patterned carbon nanotubes by electrophoresis is an alternative method to prepare field emission arrays
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Orkun Baris Kovanci
2016-03-01
Full Text Available Behavioral manipulation of codling moth with spice-based deterrents may provide an alternative control strategy. Microencapsulation technology could lead to more effective use of spice essential oils and oleoresins in the field by extending their residual activity. The feeding and oviposition deterrent potential of the microencapsulated cardamom (Elettaria cardamomum [L.] Maton oleoresin (MEC-C and eucalyptol (MEC-E were evaluated against codling moth, Cydia pomonella Linnaeus, 1758. MEC-C capsules contained both 1,8-cineole and a-terpinyl acetate, whereas MEC-E capsules contained only 1,8-cineole. In larval feeding bioassays, MEC-E exhibited the lowest feeding deterrent activity (33% while MEC-C at 100 mg mL-1 had the highest (91%. The highest oviposition deterrence activity against gravid females was also shown by MEC-C at 100 mg mL-1 with 84% effective repellency. In 2010 and 2011, two apple orchards were divided into four 1 ha blocks and sprayed with the following treatments in ultra-low volume sprays: (a MEC-E at 100 g L-1, (b MEC-C at 50 g L-1, (c MEC-C at 100 g L-1, and (d MEC-pyrethrin at 15 mL L-1. Water-treated abandoned orchards were used as negative controls. Moth catches were monitored weekly using Ajar traps baited with the combination of codlemone, pear ester, and terpinyl acetate. Based on pooled data, mean cumulative moth catch per trap per week was significantly higher in the MEC-E blocks (26.3 male and 13.5 female moths than those in other treatments except the abandoned blocks. At mid-season and pre-harvest damage assessment, the percentage of infested fruits with live larvae in the high dose MEC-C-treated blocks was reduced to 1.9% and 2.3% in 2010 and to 1.1% and 1.8% in 2011, respectively. Since fruit damage exceeded the economic damage threshold of 1%, high-dose MEC-C treatment may only offer supplementary protection against codling moth in integrated pest management programs.
Screened potted cactus plants (Opuntia ficus-indica (L.) Mill.) containing pairs of adult male and female cactus moths, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), were placed in a cactus field in St. Marks, Florida to measure oviposition patterns under field-realistic conditions. Results...
Pfau , B; Günther , C.M.; Guehrs , E; Hauet , Thomas; Yang , H; Vinh , L.; Xu , X; Yaney , D; Rick , R; Eisebitt , S; Hellwig , O
2011-01-01
International audience; Using a combination of synchrotron radiation based magnetic imaging and high-resolution transmission electron microscopy we reveal systematic correlations between the magnetic switching field and the internal nanoscale structure of individual islands in bit patterned media fabricated by Co/Pd-multilayer deposition onto pre-patterned substrates. We find that misaligned grains at the island periphery are a common feature independent of the island switching field, while i...
Czech Academy of Sciences Publication Activity Database
Przybylski, M.; Reichard, Martin; Spence, R.; Smith, C.
2007-01-01
Roč. 144, č. 11 (2007), s. 1403-1417 ISSN 0005-7959 R&D Projects: GA AV ČR KJB600930501 Institutional research plan: CEZ:AV0Z60930519 Keywords : mating system * opportunity for selection * oviposition * sexual selection Subject RIV: EG - Zoology Impact factor: 1.604, year: 2007
Wang, Fangfang; Lu, Xiaojuan; Guo, Fengxun; Gong, Haiyan; Zhang, Houshuang; Zhou, Yongzhi; Cao, Jie; Zhou, Jinlin
2017-06-15
An immunomodulatory protein designated RH36 was identified in the tick Rhipicephalus haemaphysaloides. The cDNA sequence of RH36 has 844bp and encodes a deduced protein with a predicted molecular weight of 24kDa. Bioinformatics analysis indicated that RH36 presented a degree of similarity of 34.36% with the immunomodulatory protein p36 from the tick Dermacentor andersoni. The recombinant RH36 (rRH36) expressed in Sf9 insect cells suppressed the T-lymphocyte mitogen-driven in vitro proliferation of splenocytes and the expression of several cytokines such as IL-2, IL-12, and TNF-α. Furthermore, the proliferation of splenocytes isolated from rRH36-inoculated mice was significantly lower than that in control mice, suggesting that rRH36 could directly suppress immune responses in vivo. In addition, microarray analysis of splenocytes indicated that the expression of several immunomodulatory genes was downregulated by rRH36. The silencing of the RH36 gene by RNAi led to a 37.5% decrease in the tick attachment rate 24h after placement into the rabbit ears, whereas vaccination with RH36 caused a 53.06% decrease in the tick engorgement rate. Unexpectedly, RNAi induced a significant decrease in the oviposition rate, ovary weight at day 12 after engorgement, and egg-hatching rate. The effects of RH36 on blood feeding and oviposition were further confirmed by vaccination tests using the recombinant protein. These results indicate that RH36 is a novel member of immunosuppressant proteins and affects tick blood feeding and oviposition. Copyright © 2017 Elsevier B.V. All rights reserved.
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Lima, Larissa C. de; Campos, Alcebiades R. [UNESP, Ilha Solteira, SP (Brazil). Dept. de Fitossanidade, Engenharia Rural e Solos]. E-mail: lclima@aluno.feis.unesp.br; campos@bio.feis.unesp.br
2008-03-15
Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)
Directory of Open Access Journals (Sweden)
Elumalai Arumugam
2015-05-01
Full Text Available Objective: To evaluate the pesticidal activity of antifeedant, oviposition deterrent, ovicidal and larvicidal activities of benzene, dichloromethane, diethylether, ethylacetate and methanol extracts of Rivina humilis at different concentrations against agricultural polyphagous pest Spodoptera litura (Lepidoptera: Noctuidae (S. litura. Methods: Antifeedant activities of the selected plant extract were studied as described by Isman et al. (1990, with slight modifications. For oviposition deterrent activity, ten pairs of (adult moths S. litura were subjected in five replicates. After 48 h, the numbers of eggs masses laid on treated and control leaves were recorded and the percentage of oviposition deterrence was calculated. The ovicidal activity was determined against the eggs of S. litura. Twenty five early fourth instar larvae of S. litura were exposed to various concentrations and was assayed by using the protocol of Abbott’s formula (1925; the 24 h LC50 values of the Rivina humilis leaf extract was determined by probit analysis. Results: All the extracts showed moderate antifeedant activitiy; however, significant antifeedant, ovicidal, oviposition deterrent and larvicidal activities were observed in methanol extract. Conclusions: This study showed that the selected plant can be a potent source of natural antifeedant, oviposition deterrent, ovicidal and larvicidal activities against field pest S. litura.
Localized magnetic fields in arbitrary directions using patterned nanomagnets
DEFF Research Database (Denmark)
McNeil, Robert P G; Schneble, Jeff; Kataoka, Masaya
2010-01-01
Control of the local magnetic fields desirable for spintronics and quantum information technology is not well developed. Existing methods produce either moderately small local fields or one held orientation. We present designs of patterned magnetic elements that produce remanent fields of 50 mT (...
Energy Technology Data Exchange (ETDEWEB)
Mao, Yang; Xu, Xianzhong; Xu, Wei; Ishida, Yuko; Leal, Walter S.; Ames, James B.; Clardy, Jon (Harvard-Med); (UCD)
2010-11-15
Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a pH-dependent fashion and (ii) detection of a pheromone-induced conformational change in the OBP {center_dot} pheromone complex. Although CquiOBP1 binds MOP in a pH-dependent fashion, it lacks the C terminus required for the pH-dependent release model. This study shows that CquiOBP binds MOP in an unprecedented fashion using both a small central cavity for the lactone head group and a long hydrophobic channel for its tail.
Yokoyama, Victoria Y
2012-02-01
The biology of olive fruit fly, Bactrocera oleae (Rossi), was studied in the laboratory, greenhouse, and in canning olives, Olea europaea L., in relation to California regional climates. Adults survived in laboratory tests at constant temperatures and relative humidities of 5 degrees C and 83%; 15 degrees C and 59%; 25 degrees C and 30%; and 35 degrees C and 29% for 15, 6, 3, and 2 d without provisions of food and water and for 37, 63, 25, and 4 d with provisions, respectively. In a divided greenhouse, adults survived for 8-11 d in the warm side (36 degrees C and 31% RH daytime); and in the cool side (26 degrees C and 63% RH daytime) 10 d without provisions and 203 d with provisions. A significantly greater number of adults survived in the cool side than the warm side, and with provisions than without. First and last eggs were oviposited in olive fruit when females were 6 and 90 d old, respectively. The highest number of eggs was 55 per day in 10 olive fruit oviposited by 10 28 d-old females, with maximum egg production by 13-37 d-old females. A significantly greater number of ovipositional sites occurred in all sizes of immature green fruit when exposed to adults in cages for 5 d than 2 d. Adults emerged from fruit with a height of > or = 1.0 cm or a volume of > or = 0.2 cm3. More than seven adults per 15 fruit emerged from field infested fruit with a height of 1.1 cm and volume of 0.1 cm3. Larval length was significantly different among the first, second, and third instars and ranged from 0.7 to 1.6, 2.4-4.3, and 4.8-5.6 mm at 14 degrees C; 0.8-1.1, 1.9-2.9, and 3.9-4.4 mm at 21 degrees C, and 0.7-1.3, 2.4-2.9, and 4.4-4.8 mm at 26 degrees C, respectively. Survival of pupae to the adult stage was significantly lower at 26 degrees C than 14 degrees C or 21 degrees C. The period of adult emergence began at 38, 14, and 11 d over a period of 8, 5, and 1 d at 14, 21, and 26 degrees C, respectively. Findings were related to the occurrence and control of California
Agent-based modelling of shifting cultivation field patterns, Vietnam
DEFF Research Database (Denmark)
Jepsen, Martin Rudbeck; Leisz, S.; Rasmussen, K.
2006-01-01
Shifting cultivation in the Nghe An Province of Vietnam's Northern Mountain Region produces a characteristic land-cover pattern of small and larger fields. The pattern is the result of farmers cultivating either individually or in spatially clustered groups. Using spatially explicit agent...
Zheng, S.J.; Snoeren, T.A.L.; Hogewoning, S.W.; Loon, van J.J.A.; Dicke, M.
2010-01-01
Optical plant characteristics are important cues to plant-feeding insects. In this article, we demonstrate for the first time that silencing the phytoene desaturase (PDS) gene, encoding a key enzyme in plant carotenoid biosynthesis, affects insect oviposition site selection behaviour. Virus-induced
Ewing, Ryan C.; Peyret, Aymeric-Pierre B.; Kocurek, Gary; Bourke, Mary
2010-08-01
High-Resolution Imaging Science Experiment (HiRISE) imagery of the central Olympia Undae Dune Field in the north polar region of Mars shows a reticulate dune pattern consisting of two sets of nearly orthogonal dune crestlines, with apparent slipfaces on the primary crests, ubiquitous wind ripples, areas of coarse-grained wind ripples, and deflated interdune areas. Geomorphic evidence and dune field pattern analysis of dune crest length, spacing, defect density, and orientation indicates that the pattern is complex, representing two constructional generations of dunes. The oldest and best-organized generation forms the primary crestlines and is transverse to circumpolar easterly winds. Gross bed form-normal analysis of the younger pattern of crestlines indicates that it emerged with both circumpolar easterly winds and NE winds and is reworking the older pattern. Mapping of secondary flow fields over the dunes indicates that the most recent transporting winds were from the NE. The younger pattern appears to represent an influx of sediment to the dune field associated with the development of the Olympia Cavi reentrant, with NE katabatic winds channeling through the reentrant. A model of the pattern reformation based upon the reconstructed primary winds and resulting secondary flow fields shows that the development of the secondary pattern is controlled by the boundary condition of the older dune topography.
Directory of Open Access Journals (Sweden)
Rodrigo F. Krüger
2004-06-01
Full Text Available Aspects related to the longevity and oviposition of Ophyra albuquerquei Lopes, 1985 are studied. Males had a mean lifespan longer than females (40.24 vs. 33.15 days, respectively, while still possessing qualitative advantages during this period. Females O. albuquerquei were fed on powdered milk, fish flour, refined sugar and water, and provided fish flour and moistened sawdust for oviposition. The length of the oviposition period for females was 46.75 days, and most of the deposition of the eggs occurred in the first days of the colony. Females completed 50% of their egg deposition by Day 16, seven days before the large last mortality peak and about 12 days after the first oviposition in the colony. Females deposited an average of 184 eggs per individual. Mortality of males, unlike females, was low until the 28th day, and increased thereafter. It was demonstrated that it is possible to maintain colonies of this species under laboratory conditions for at least 28 days with high fertility and low cost.
Field emission from patterned SnO2 nanostructures
International Nuclear Information System (INIS)
Zhang Yongsheng; Yu Ke; Li Guodong; Peng Deyan; Zhang Qiuxiang; Hu Hongmei; Xu Feng; Bai Wei; Ouyang Shixi; Zhu Ziqiang
2006-01-01
A simple and reliable method has been developed for synthesizing finely patterned tin dioxide (SnO 2 ) nanostructure arrays on silicon substrates. A patterned Au catalyst film was prepared on the silicon wafer by radio frequency (RF) magnetron sputtering and photolithographic patterning processes. The patterned SnO 2 nanostructures arrays, a unit area is of ∼500 μm x 200 μm, were synthesized via vapor phase transport method. The surface morphology and composition of the as-synthesized SnO 2 nanostructures were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanism of formation of SnO 2 nanostructures was also discussed. The measurement of field emission (FE) revealed that the as-synthesized SnO 2 nanorods, nanowires and nanoparticles arrays have a lower turn-on field of 2.6, 3.2 and 3.9 V/μm, respectively, at the current density of 0.1 μA/cm 2 . This approach must have a wide variety of applications such as fabrications of micro-optical components and micropatterned oxide thin films used in FE-based flat panel displays, sensor arrays and so on
Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns.
Yan, Wei-Cheng; Xie, Jingwei; Wang, Chi-Hwa
2018-06-06
Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous electrospray deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial-cell interactions and sensing.
Joachim-Bravo, Iara Sordi; Silva-Neto, Alberto Moreira da
2004-01-01
The influence of four host fruits, orange (Citrus sinensis L.), papaya (Carica papaya L.), mango (Mangifera indica L.) and apple (Malus domestica Borkh) on oviposition behavior of Ceratitis capitata (Wiedemann, 1824) was evaluated. Experiments were carried out on two C. capitata laboratory-reared populations: one with artificial diet for 10 years with periodic introduction of wild flies and other reared with artificial diet for 20 years without wild flies introduction. In acceptance experimen...
Design of flow-field patterns for proton exchange membrane fuel cell application
International Nuclear Information System (INIS)
Rosli, M.I.; Wan Ramli Wan Daud; Kamaruzzaman Sopian; Jaafar Sahari
2006-01-01
Fuel cells are electrochemical devices that produce electricity at high efficiency without combustion. Fuel cells are emerging as viable candidates as power sources in many applications, including road vehicles, small-scale power stations, and possibly even portable electronics. This paper addresses the design of flow-field patterns for proton exchange membrane fuel cell (PEMFC). The PEMFC is a low-temperature fuel cell, in which a proton conductive polymer membrane is used as the electrolyte. In PEMFC, flow-field pattern is one important thing that effects the performance of PEMFC. This paper present three types of flow-field pattern that will be consider to be testing using CFD analysis and by experimental. The design look detail on to their shape and dimension to get the best pattern in term of more active electrode area compare to electrode area that will be used. Another advantage and disadvantage for these three type of flow-field patterns from literature also compared in this paper
Mboera, L.E.G.; Takken, W.; Mdira, K.Y.; Pickett, J.A.
2000-01-01
The effectiveness of traps baited with (5R,6S)-6-acetoxy-5-hexadecanolide (the synthetic oviposition pheromone) and grass infusions in sampling a population of gravid Culex quinquefasciatus Say was conducted in Muheza, Northeast Tanzania. A counterflow geometry (CFG) trap baited with pheromone and
Navarro, D.M.A.F.; Oliveira, de P.E.S.; Potting, R.P.J.; Brito, A.C.; Fital, S.J.F.; Goulart Sant Ana, A.E.
2003-01-01
The selection of oviposition sites by the yellow-fever mosquito, Aedes aegypti , was studied in the laboratory. The repellent or attractant effects of salinity and the presence of bacteria in water collected from a local community on the Brazilian coast were investigated. Water contaminated with
Lorioux, Sophie; DeNardo, Dale F; Gorelick, Root; Lourdais, Olivier
2012-04-15
Embryonic life is particularly sensitive to its surroundings, and the developmental environment can have long-lasting effects on offspring. In oviparous species, the impacts of the developmental environment on offspring traits are mostly examined during development within the egg. However, as more than 25% of the development of squamate reptiles can occur prior to oviposition, we explored the effect of thermal conditions on development prior to oviposition in an oviparous snake species, the Children's python (Antaresia childreni). We housed gravid female pythons under three thermal cycles: an optimal regime that reflected maternal preference in a non-constrained environment (constant preferred body temperature of gravid females, T(set)=31.5°C) and two mildly suboptimal regimes that shared the same mean temperature of 27.7°C, but differed in the duration at T(set). In one of the constraining regimes, females had access to T(set) for 4 h daily whereas in the other regime, females never reached T(set) (maximal temperature of 29.0°C). Thermal treatments were maintained throughout gravidity in all three groups, but, after oviposition, all eggs were incubated at T(set) until hatching. Compared with the optimal regime, the two suboptimal regimes had a longer duration of gravidity, which resulted in delayed hatching. Between the two suboptimal regimes, gravidity was significantly shorter in the treatment that included time at T(set). Furthermore, suboptimal regimes influenced offspring traits at hatching, including body morphology, antipredator behavior, strength and metabolism. However, partial access to maternal T(set) significantly enhanced several offspring traits, including performance. Our results demonstrate the importance of time at T(set) on early development and suggest an adaptive significance of maternal thermoregulation prior to oviposition.
House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), common pests on equine facilities, were studied in the laboratory to determine their oviposition preferences and larval development on six substrates commonly found on equine facilities. The substrates...
Sumba, L.A.; Guda, T.O.; Deng, A.L.; Hassanali, A.; Beier, J.C.; Knols, B.G.J.
2004-01-01
Laboratory studies were carried out to investigate the role of larval habitat-derived microorganisms in the production of semiochemicals for oviposition site selection by Anopheles gambiae Giles sensu stricto mosquitoes. Dual-choice bioassays with gravid females were conducted in standard mosquito
Stabilization and destabilization effects of the electric field on stochastic precipitate pattern
Lagzi, István; Izsak, F.
2004-01-01
Stabilization and destabilization effects of an applied electric field on the Liesegang pattern formation in low concentration gradient were studied with numerical model simulations. In the absence of an electric field pattern formation exhibits increasingly stochastic behaviour as the initial
Directory of Open Access Journals (Sweden)
Kamala Jayanthi Pagadala Damodaram
Full Text Available The Oriental fruit fly, Bactrocera dorsalis (Hendel is an important quarantine pest around the globe. Although measures for its control are implemented worldwide through IPM and male annihilation, there is little effect on their population. Hence, there is a need for new strategies to control this minacious pest. A strategy that has received negligible attention is the induction of 'natural plant defenses' by phytohormones. In this study, we investigated the effect of salicylic acid (SA treatment of mango fruit (cv. Totapuri on oviposition and larval development of B. dorsalis. In oviposition choice assays, gravid females laid significantly less eggs in SA treated compared to untreated fruit. Headspace volatiles collected from SA treated fruit were less attractive to gravid females compared to volatiles from untreated fruit. GC-MS analysis of the headspace volatiles from SA treated and untreated fruit showed noticeable changes in their chemical compositions. Cis-ocimene and 3-carene (attractants to B. dorsalis were reduced in the headspace volatiles of treated fruit. Further, reduced pupae formation and adult emergence was observed in treated fruit compared to control. Increased phenol and flavonoid content was recorded in treated fruit. We also observed differential expression of anti-oxidative enzymes namely catalase (CAT, polyphenoloxidase (PPO and peroxidase (POD. In summary, the results indicate that SA treatment reduced oviposition, larval development and adult emergence of B. dorsalis and suggest a role of SA in enhancing mango tolerance to B. dorsalis.
Patterns of magnetic field merging sites on the magnetopause
International Nuclear Information System (INIS)
Luhmann, J.G.; Walker, R.J.; Russell, C.T.; Crooker, N.U.; Spreiter, J.R.; Stahara, S.S.
1984-01-01
Several years ago, Crooker presented a qualitative picture of the merging sites on the magnetopause defined as the points where the magnetospheric and magnetosheath field are antiparallel. However, Cowley pointed out that merging can also occur where these fields are not exactly antiparallel, but merely have antiparallel components. Using realistic models of the magnetosphere and magnetosheath magnetic fields, the angles between the fields at the magnetopause boundary were determined for different interplanetary field orientations, including radial field and Parker spiral field. The results are summarized in Figure 1, which displays contours on the dayside magnetopause (viewed from the sun, i.e., the GSE Y-Z plane projection) of equal value of the cosine of the angle between the magnetospheric and magnetosheath model fields. Only contours with negative values, implying some antiparallel component, are shown. Values at the contours, starting with the contour filled with shading, are -.98, -.95, -.9, -.8, -.7, -.6, -.5, -.4, -.3, -.2, -.1, -.0. The interplanetary field orientations are indicated in vector notation in the lower right corners. In particular, the pattern for a 45 0 cone angle is shown in the fourth diagram in the right hand column and patterns for northward and southward fields occupy the first position in the first column and the second position in the right hand column. These results can be used for comparisons with observed distribution of flux transfer events and for studies of magnetospheric particle leakage
Modulating patterns of two-phase flow with electric fields.
Liu, Dingsheng; Hakimi, Bejan; Volny, Michael; Rolfs, Joelle; Anand, Robbyn K; Turecek, Frantisek; Chiu, Daniel T
2014-07-01
This paper describes the use of electro-hydrodynamic actuation to control the transition between three major flow patterns of an aqueous-oil Newtonian flow in a microchannel: droplets, beads-on-a-string (BOAS), and multi-stream laminar flow. We observed interesting transitional flow patterns between droplets and BOAS as the electric field was modulated. The ability to control flow patterns of a two-phase fluid in a microchannel adds to the microfluidic tool box and improves our understanding of this interesting fluid behavior.
Magnetic field induced flow pattern reversal in a ferrofluidic Taylor-Couette system.
Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng
2015-12-21
We investigate the dynamics of ferrofluidic wavy vortex flows in the counter-rotating Taylor-Couette system, with a focus on wavy flows with a mixture of the dominant azimuthal modes. Without external magnetic field flows are stable and pro-grade with respect to the rotation of the inner cylinder. More complex behaviors can arise when an axial or a transverse magnetic field is applied. Depending on the direction and strength of the field, multi-stable wavy states and bifurcations can occur. We uncover the phenomenon of flow pattern reversal as the strength of the magnetic field is increased through a critical value. In between the regimes of pro-grade and retrograde flow rotations, standing waves with zero angular velocities can emerge. A striking finding is that, under a transverse magnetic field, a second reversal in the flow pattern direction can occur, where the flow pattern evolves into pro-grade rotation again from a retrograde state. Flow reversal is relevant to intriguing phenomena in nature such as geomagnetic reversal. Our results suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which can be realized in laboratory experiments with potential applications in the development of modern fluid devices.
Remotely Sensing Larval Population Dynamics of Rice Field Anophelines
Beck, Louisa R.; Dister, Sheri W.; Wood, Byron L.; Washino, Robert K.
1997-01-01
The primary objective of both studies was to determine if RS and GIS techniques could be used to distinguish between high and low larval-producing rice fields in California. Results of the first study suggested that early-season green-up and proximity to livestock pastures were positively correlated with high larval abundance. Based on the early-season spectral differences between high and low larval-producing fields, it appeared that canopy development and tillering influenced mosquito habitat quality. At that time, rice fields consisted of a mixture of plants and water, a combination that allowed An. freeborni females to lay eggs in partial sunlight, protected from both predators and wind. This established a population earlier in the season than in other, 'less-green' fields where tillering and plant emergence was too minimal for ovipositioning. The study also indicated the importance of the distance that a mosquito would have to fly in order to take a bloodmeal prior to ovipositing. These associations were fully explored in an expanded study two years later. The second study confirmed the positive relationship between early season canopy development and larval abundance, and also demonstrated the relationship between abundance and distance-to-pasture. The association between greenness (as measured using NDVI), distance-to-pasture, and abundance is illustrated. The second study also indicated the siginificance of the landscape context of rice fields for larval production. Fields that included opportunities for feeding and resting within the flight range of the mosquito had higher abundances than did fields that were in a homogeneous rice area.
International Nuclear Information System (INIS)
Soglia, Maria da Conceicao M.; Bueno, Vanda Helena Paes; Carvalho, Livia Mendes
2007-01-01
This work aimed to evaluate the development time and the consumption of Orius insidiosus (Say, 1832) feeding on Aphis gossypii Glover, 1877 as well as its oviposition behavior on two chrysanthemum cut cultivars. The trials were conducted in climatic chamber at 25 ± 1 deg C, RH 70 ± 10% and 12h photo phase. Nymphs of the predator, less than 24h old, were kept individually in petri dishes (5cm) with 20 nymphs of A. gossypii (first, second and third instar) on leaf disc (4 cm) of each cultivar ('White Reagan' and 'Yellow Snowdon') in a layer of agar-water (1%). Petiole of each chrysanthemum cultivar as oviposition substrate was evaluated and the females were feeding on eggs of Anagasta kuehniella (Zeller, 1879). The predator complete its development feeding on A. gossypii kept in both cultivars. The duration of nymphal phase of O. insidiosus were 21.1 and 18.3 days on 'White Reagan' and 'Yellow Snowdon', respectively. The consumption of the females of O. insidiosus was higher (P<0.01) on A. gossypii in 'White Reagan' (2.63 nymphs) compared to the consumption in 'Yellow Snowdon' (0.7 nymphs). Females of O. insidiosus oviposited in petiole of both cultivars with 22.5 and 23.3 eggs/female on 'White Reagan' and 'Yellow Snowdon', respectively. Release of O. insidiosus on chrysanthemum crops could be important to decrease the A. gossypii population, as the predator completes its development having this aphid as prey, and the chrysanthemum cultivars offer conditions to colonization and establishment of O. insidiosus. (author)
Czech Academy of Sciences Publication Activity Database
Das, B. C.; Dixon, Anthony F. G.
2011-01-01
Roč. 1, č. 1 (2011), s. 57-60 ISSN 1805-0174 R&D Projects: GA MŠk LC06073; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Adalia bipunctata * Aphididae * arrestant * Coccinellidae * cues for oviposition * honeydew * minimum aphid density * patch quality * predator Subject RIV: EH - Ecology, Behaviour
Czech Academy of Sciences Publication Activity Database
Phillips, A.; Reichard, Martin; Smith, Carl
2017-01-01
Roč. 126, April (2017), s. 187-194 ISSN 0003-3472 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : maternal effect * mussel * oviposition site cue * reproduction * Rhodeus * sexual conflict Subject RIV: EG - Zoology OBOR OECD: Behavioral sciences biology Impact factor: 2.869, year: 2016
Near-field imaging of interference pattern of counterpropagating evanescent waves
DEFF Research Database (Denmark)
Bozhevolnyi, Sergey I.; Bozhevolnaya, Elena A.
1999-01-01
It is generally accepted that measurement of of the contrast of the intensity interference pattern formed by two counterpropagating evanescent waves can be used to characterize the resolving power of a collection near-field microscope. We argue that, if the light collected by a fiber probe propag...... be equal to the contrast of the interference pattern....
Brodie, Bekka S; Babcock, Tamara; Gries, Regine; Benn, Arlan; Gries, Gerhard
2016-01-01
We investigated foraging decisions by adult females of the common green bottle fly, Lucilia sericata, in accordance with their physiological state. When we gave female flies a choice between visually occluded, fresh canine feces (feeding site) and a CO2-euthanized rat (carrion oviposition site), 3-d-old "protein-starved" females responded equally well to feces and carrion, whereas protein-fed gravid females with mature oocytes responded only to carrion, indicating resource preferences based on a fly's physiological state. Dimethyl trisulfide (DMTS) is known to attract gravid L. sericata females to carrion. Therefore, we analyzed headspace from canine feces by gas chromatographic-electroantennographic detection (GC-EAD) and GC/mass spectrometry. In bioassays, of the 17 fecal odorants that elicited GC-EAD responses from fly antennae, a blend of indole and one or more of the alcohols phenol, m-/p-cresol and 1-octen-3-ol proved as attractive to flies as canine feces. Unlike young females, gravid females need to locate carrion for oviposition and distinguish between fresh and aging carrion, the latter possibly detrimental to offspring. Gravid female L. sericata accomplish this task, in part, by responding to trace amounts of DMTS emanating from fresh carrion and by discriminating against carrion as soon it begins to produce appreciable amounts of indole, which is also the second-most abundant semiochemical in fresh canine feces, and apparently serves as an indicator of food rather than oviposition resources. Our results emphasize the importance of studying foraging choices by flies in accordance with their physiological stage.
Switching field distribution and magnetization reversal process of FePt dot patterns
Energy Technology Data Exchange (ETDEWEB)
Ishio, S., E-mail: ishio@gipc.akita-u.ac.jp [Department of Materials Science and Engineering, Akita University, Akita 010-8502 (Japan); Takahashi, S.; Hasegawa, T.; Arakawa, A.; Sasaki, H. [Department of Materials Science and Engineering, Akita University, Akita 010-8502 (Japan); Yan, Z.; Liu, X. [Venture Business Laboratory, Akita University, Tegata Gakuen-machi, Akita 010-8502 (Japan); Kondo, Y.; Yamane, H.; Ariake, J. [Akita Prefectural R and D Center, 4-21 Sanuki, Akita 010-1623 (Japan); Suzuki, M.; Kawamura, N.; Mizumaki, M. [Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)
2014-06-01
The fabrication of FePt nanodots with a high structural quality and the control of their switching fields are key issues in realizing high density bit pattern recording. We have prepared FePt dot patterns for dots with 15–300 nm diameters by electron beam lithography and re-annealing, and studied the relation between magnetization reversal process and structure of FePt nanodots. The switching field (H{sub sw}) of dot patterns re-annealed at 710 °C for 240 min showed a bimodal distribution, where a higher peak was found at 5–6 T, and a lower peak was found at ∼2 T. It was revealed by cross-sectional TEM analysis that the structure of dots in the pattern can be classified into two groups. One group has a high degree of order with well-defined [0 0 1] crystalline growth, and the other group includes structurally-disturbed dots like [1 1 1] growth and twin crystals. This structural inhomogeneity causes the magnetic switching field distribution observed. - Highlights: • FePt dot patterns with 15–100 nm dot diameters were prepared by EB lithography. • Maximum coercivity of 30 kOe was found in the dot pattern with 30 nm in diameter. • Magnetization reversal was studied on the base of TEM analysis and LLG simulation.
Malheiro, Ricardo; Casal, Susana; Cunha, Sara C; Baptista, Paula; Pereira, José Alberto
2016-01-01
The olive fly, Bactrocera oleae (Rossi), is a monophagous pest that displays an oviposition preference among cultivars of olive (Olea europaea L.). To clarify the oviposition preference, the olive leaf volatiles of three olive cultivars (Cobrançosa, Madural and Verdeal Transmontana) were assessed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) at six different periods of olive fruit maturation and degrees of infestation. A total of 39 volatiles were identified, mainly esters and alcohols, with a minor percentage of aldehydes, ketones and terpenic compounds, including sesquiterpenes. At sampling dates with higher degrees of infestation, cv. Cobrançosa had, simultaneously, significantly lower infestation degrees and higher volatile amounts than the other two cultivars, with a probable deterrent effect for oviposition. The green leaf volatiles (GLVs) (Z)-3-hexen-1-ol and (Z)-3-hexen-1-ol acetate) were the main compounds identified in all cultivars, together with toluene. The abundance of GLVs decreased significantly throughout maturation, without significant differences among cultivars, while toluene showed a general increase and positive correlation with olive fly infestation levels. The results obtained could broaden our understanding of the roles of various types and amounts of olive volatiles in the environment, especially in olive fly host selection and cultivar preference. Copyright © 2015 Elsevier Ltd. All rights reserved.
Pimenta de Oliveira, Sofia; Dantas de Oliveira, Caroline; Viana Sant'Anna, Mauricio Roberto; Carneiro Dutra, Heverton Leandro; Caragata, Eric Pearce; Moreira, Luciano Andrade
2017-08-01
Blood feeding in Aedes aegypti is essential for reproduction, but also permits the mosquito to act as a vector for key human pathogens such as the Zika and dengue viruses. Wolbachia pipientis is an endosymbiotic bacterium that can manipulate the biology of Aedes aegypti mosquitoes, making them less competent hosts for many pathogens. Yet while Wolbachia affects other aspects of host physiology, it is unclear whether it influences physiological processes associated with blood meal digestion. To that end, we examined the effects of wMel Wolbachia infection in Ae. aegypti, on survival post-blood feeding, blood meal excretion, rate of oviposition, expression levels of key genes involved in oogenesis, and activity levels of trypsin blood digestion enzymes. We observed that wMel infection altered the rate and duration of blood meal excretion, delayed the onset of oviposition and was associated with a greater number of eggs being laid later. wMel-infected Ae. aegypti also had lower levels of key yolk protein precursor genes necessary for oogenesis. However, all of these effects occurred without a change in trypsin activity. These results suggest that Wolbachia infection may disrupt normal metabolic processes associated with blood feeding and reproduction in Ae. aegypti. Copyright © 2017 Elsevier Ltd. All rights reserved.
Multi-field electron emission pattern of 2D emitter: Illustrated with graphene
Luo, Ma; Li, Zhibing
2016-11-01
The mechanism of laser-assisted multi-field electron emission of two-dimensional emitters is investigated theoretically. The process is basically a cold field electron emission but having more controllable components: a uniform electric field controls the emission potential barrier, a magnetic field controls the quantum states of the emitter, while an optical field controls electron populations of specified quantum states. It provides a highly orientational vacuum electron line source whose divergence angle over the beam plane is inversely proportional to square root of the emitter height. Calculations are carried out for graphene with the armchair emission edge, as a concrete example. The rate equation incorporating the optical excitation, phonon scattering, and thermal relaxation is solved in the quasi-equilibrium approximation for electron population in the bands. The far-field emission patterns, that inherit the features of the Landau bands, are obtained. It is found that the optical field generates a characteristic structure at one wing of the emission pattern.
Sylvestre, Gabriel; Gandini, Mariana; Maciel-de-Freitas, Rafael
2013-01-01
Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV) on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd) and 3(rd) weeks post-infection, and also longer overall blood-feeding times in the 3(rd) week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd) week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.
Directory of Open Access Journals (Sweden)
Gabriel Sylvestre
Full Text Available BACKGROUND: Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. METHODS/PRINCIPAL FINDINGS: After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd and 3(rd weeks post-infection, and also longer overall blood-feeding times in the 3(rd week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. CONCLUSIONS: The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.
Ewing, Ryan C.; Peyret, Aymeric-Pierre B.; Kocurek, Gary; Bourke, Mary
2010-01-01
High-Resolution Imaging Science Experiment (HiRISE) imagery of the central Olympia Undae Dune Field in the north polar region of Mars shows a reticulate dune pattern consisting of two sets of nearly orthogonal dune crestlines, with apparent slipfaces on the primary crests, ubiquitous wind ripples, areas of coarse-grained wind ripples, and deflated interdune areas. Geomorphic evidence and dune field pattern analysis of dune crest length, spacing, defect density, and orientation indicates that ...
Pond dyes are Culex mosquito oviposition attractants
Directory of Open Access Journals (Sweden)
Natali Ortiz Perea
2017-05-01
Full Text Available Background British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes. Methods Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat. Results Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more
Influences of Cry1Ac broccoli on larval survival and oviposition of diamondback moth.
Yi, Dengxia; Cui, Shusong; Yang, Limei; Fang, Zhiyuan; Liu, Yumei; Zhuang, Mu; Zhang, Yangyong
2015-01-01
Larval survival and oviposition behavior of three genotypes of diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), (homozygous Cry1Ac-susceptibile, Cry1Ac-resistant, and their F1 hybrids), on transgenic Bacillus thuringiensis (Bt) broccoli expressing different levels of Cry1Ac protein were evaluated in laboratory. These Bt broccoli lines were designated as relative low, medium, and high, respectively, according to the Cry1Ac content. Untransformed brocccoli plants were used as control. Larval survival of diamondback moth on non-Bt leaves was not significantly different among the three genotypes. The Cry1Ac-resistant larvae could survive on the low level of Bt broccoli plants, while Cry1Ac-susceptible and F1 larvae could not survive on them. The three genotypes of P. xylostella larvae could not survive on medium and high levels of Bt broccoli. In oviposition choice tests, there was no significant difference in the number of eggs laid by the three P. xylostella genotypes among different Bt broccoli plants. The development of Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella on intact Bt plants was also tested in greenhouse. All susceptible P. xylostella larvae died on all Bt plants, while resistant larvae could survive on broccoli, which expresses low Cry1Ac protein under greenhouse conditions. The results of the greenhouse trials were similar to that of laboratory tests. This study indicated that high dose of Bt toxins in broccoli cultivars or germplasm lines is required for effective resistance management. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.
Lucantoni, L; Giusti, F; Cristofaro, M; Pasqualini, L; Esposito, F; Lupetti, P; Habluetzel, A
2006-12-01
Secondary metabolites of the neem tree (Azadirachta indica A. Juss., Meliaceae) exhibit a wide range of biological activities in insects. However, few studies have addressed the effects of neem extracts or compounds in arthropods of medical importance. In this study, a laboratory strain of Anopheles stephensi was used to assess the effects of a commercial formulation (Neem Azal) (NA)), containing azadirachtin A at 34%, on blood feeding, oviposition and oocyte ultrastructure. Oral administration of Neem Azal) to A. stephensi females through artificial blood meals did impair blood intake and oviposition in a concentration dependent manner. Similar results were obtained on females, which had consumed Neem Azal) in sucrose solution before taking a blood meal of plain blood. Neem treated females displayed a delay in oocyte development in both the phase of vitellogenesis and the phase of choriogenesis. The ultrastructural studies on ovaries from Neem Azal) treated females revealed distinct structural modifications indicative of: (i) a complete block of oogenesis, (ii) impairment of vitellogenesis and vitelline envelope formation, (iii) a severe degeneration of follicle cells. In agreement with results obtained in other insects, this study indicates that Neem Azal) impairs hormone control of oogenesis and exerts a cytotoxic effect on both follicular cells and oocytes of the Asian malaria vector A. stephensi.
Silva-Soares, Nuno F; Nogueira-Alves, A; Beldade, P; Mirth, Christen Kerry
2017-06-07
Understanding how species adapt to new niches is a central issue in evolutionary ecology. Nutrition is vital for the survival of all organisms and impacts species fitness and distribution. While most Drosophila species exploit rotting plant parts, some species have diversified to use ripe fruit, allowing earlier colonization. The decomposition of plant material is facilitated by yeast colonization and proliferation. These yeasts serve as the main protein source for Drosophila larvae. This dynamic rotting process entails changes in the nutritional composition of the food and other properties, and animals feeding on material at different stages of decay are expected to have behavioural and nutritional adaptations. We compared larval performance, feeding behaviour and adult oviposition site choice between the ripe fruit colonizer and invasive pest Drosophila suzukii, and a closely-related rotting fruit colonizer, Drosophila biarmipes. Through the manipulation of protein:carbohydrate ratios in artificial diets, we found that D. suzukii larvae perform better at lower protein concentrations and consume less protein rich diets relative to D. biarmipes. For adult oviposition, these species differed in preference for substrate hardness, but not for the substrate nutritional composition. Our findings highlight that rather than being an exclusive specialist on ripe fruit, D. suzukii's adaptation to use ripening fruit allow it to colonize a wider range of food substrates than D. biarmipes, which is limited to soft foods with higher protein concentrations. Our results underscore the importance of nutritional performance and feeding behaviours in the colonization of new food niches.
Directory of Open Access Journals (Sweden)
Rotraut A. G. B. Consoli
1988-06-01
Full Text Available Several larval and pupal products of Aedes fluviatilis (Lutz were tested for their influence on the oviposition behaviour of females of the same species. Significant (alfa = 0,05 atractiveness was shown by: larval water, previously containing 5 to 15 larvae/1,5 ml; larval water, preserved up to 38 days; evaporate and reconstructed larval water extracts up to 2 years after production and water filtered through fresh or dried ground larvae. hexanic larval water extracts and water filtered through fresh or dired ground pupae did not influence oviposition.Estudou-se a influência sobre o comportamento de oviposição das fêmeas de Aedes fluviatilis (Lutz de produtos derivados das formas imaturas da mesma espécie. As fêmeas foram atraídas significativamente (x=0,05 por ocasião da ovoposição por: água destilada que contivera 5 ou 15 larvas/1,5 ml, a mesma água (5 larvas/1,5 mlapós sua preservação por 38 dias; extratos evaporados e reconstituídos de água que conteve larvas, por até dois anos a sua produção, e filtrados de macerados frescos e secos de larvas. Extratos hexânicos de água que conteve larvas e filtrados de macerados descos e secos de pupas não atraíram a ovoposição das fêmeas.
Hajiaghajani, Amirhossein; Abdolali, Ali
2018-05-01
In cancer therapy, magnetic drug targeting is considered as an effective treatment to reduce chemotherapy's side effects. The accurate design and shaping of magnetic fields are crucial for healthy cells to be immune from chemotherapeutics. In this paper, arbitrary 2-dimensional spatial patterns of magnetic fields from DC to megahertz are represented in terms of spatial Fourier spectra with sinusoidal eigenfunctions. Realization of each spatial frequency was investigated by a set of elliptical coils. Therefore, it is shown that the desired pattern was synthesized by simultaneous use of coil sets. Currents running on each set were obtained via fast and straightforward analytical Fourier series calculation. Experimentally scanned sample patterns were in close agreement with full wave analysis. Discussions include the evaluation of the Fourier series approximation error and cross-polarization of produced magnetic fields. It was observed that by employing the controlled magnetic field produced by the proposed setup, we were able to steer therapeutic particles toward the right or left half-spheres of the breast, with an efficiency of 90%. Such a pattern synthesizer may be employed in numerous human arteries as well as other bioelectromagnetic patterning applications, e.g., wireless power transfer, magnetic innervation, and tomography. Bioelectromagnetics. 39:325-338, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.
2014-01-01
Background Electric nets (e-nets) are used to analyse the flight behaviour of insects and have been used extensively to study the host-oriented flight of tsetse flies. Recently we adapted this tool to analyse the oviposition behaviour of gravid malaria vectors, Anopheles gambiae s.s., orienting towards aquatic habitats and traps by surrounding an artificial pond with e-nets and collecting electrocuted mosquitoes on sticky boards on the ground next to the nets. Here we study whether e-nets themselves affect the responses of gravid An. gambiae s.s.. Methods Dual-choice experiments were carried out in 80 m2 screened semi-field systems where 200 gravid An. gambiae s.s. were released each night for 12 nights per experiment. The numbers of mosquito landing on or approaching an oviposition site were studied by adding detergent to the water in an artificial pond or surrounding the pond with a square of e-nets. We also assessed whether the supporting framework of the nets or the sticky boards used to retain electrocuted mosquitoes influenced the catch. Results Two similar detergent treated ponds presented in choice tests caught an equal proportion of the mosquitoes released, whereas a pond surrounded by e-nets caught a higher proportion than an open pond (odds ratio (OR) 1.7, 95% confidence interval (CI) 1.1 - 2.7; p electric nets and the yellow boards on the approach of gravid females towards a pond suggests that the tower-like construction of the square of electric nets did not restrict the approach of females but the yellow sticky boards on the ground attract gravid females to a source of water (OR 2.7 95% CI 1.7 – 4.3; p trapping efficiency of the electric nets is increased when large yellow sticky boards are placed on the ground next to the e-nets to collect electrocuted mosquitoes, possibly because of increased visual contrast to the aquatic habitat. It is therefore important when comparing two treatments that the same trapping device is used in both. The
Zalucki, M P; Cunningham, J P; Downes, S; Ward, P; Lange, C; Meissle, M; Schellhorn, N A; Zalucki, J M
2012-08-01
Cotton growing landscapes in Australia have been dominated by dual-toxin transgenic Bt varieties since 2004. The cotton crop has thus effectively become a sink for the main target pest, Helicoverpa armigera. Theory predicts that there should be strong selection on female moths to avoid laying on such plants. We assessed oviposition, collected from two cotton-growing regions, by female moths when given a choice of tobacco, cotton and cabbage. Earlier work in the 1980s and 1990s on populations from the same geographic locations indicated these hosts were on average ranked as high, mid and low preference plants, respectively, and that host rankings had a heritable component. In the present study, we found no change in the relative ranking of hosts by females, with most eggs being laid on tobacco, then cotton and least on cabbage. As in earlier work, some females laid most eggs on cotton and aspects of oviposition behaviour had a heritable component. Certainly, cotton is not avoided as a host, and the implications of these finding for managing resistance to Bt cotton are discussed.
Soler, J.J.; Schaper, S.V.; Bezemer, T.M.; Cortesero, A.M.; Hoffmeister, T.S.; Van der Putten, W.H.; Vet, L.E.M.; Harvey, J.A.
2009-01-01
1. Several studies have shown that above- and belowground insects can interact by influencing each others growth, development, and survival when they feed on the same host-plant. In natural systems, however, insects can make choices on which plants to oviposit and feed. A field experiment was
ANALYSIS ON THE DYNAMICS OF SPATIAL DISTRIBUTION PATTERN OF MIXED SPIDER POPULATION IN RICE FIELD
Institute of Scientific and Technical Information of China (English)
ZhiWang; Zhe-mingYuan; Da-xiangSong; Ming-shengZhu
2004-01-01
The results make it clear that there are total 11 families, 29 genera and 43 species of spiders in the rice field of Dong Fang Hong Farm. Among them, there are 8 families, 19 genera and 28 species in the early rice field, and 10 families, 27 genera and 36 species in the late rice field. The spatial distribution pattern of mixed spider populations in rice fields was different during different development stages of rice plant. During the prophase, metaphase and anaphase of early rice plant development, the spatial distribution pattern of mixed spider populations was aggregative, random and aggregative respectively. During the prophase, metaphase and anaphase of late rice plant development, the spatial distribution pattern was uniform, aggregative and uniform respectively.
Role of methyl salicylate on oviposition deterrence in Arabidopsis thaliana.
Groux, Raphaël; Hilfiker, Olivier; Gouhier-Darimont, Caroline; Peñaflor, Maria Fernanda Gomes Villalba; Erb, Matthias; Reymond, Philippe
2014-07-01
Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae.
Diel Behavioral Activity Patterns in Adult Solitarious Desert Locust, Schistocerca gregaria (Forskål
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Sidi Ould Ely
2011-01-01
Full Text Available The responses of adult solitarious desert locust to odors from a host plant were evaluated in a two-choice wind tunnel. Solitarious desert locusts collected from the field (Red Sea Coast were more attracted to volatiles from potted Heliotropium ovalifolium in scotophase than in photophase. The attraction towards the host plant odors rather than to clean air, in both photophase and scotophase, concurs with previous observations on oviposition preferences near these plants. Diel behavioral activity patterns of adult solitarious desert locusts Schistocerca gregaria (Forskål that were collected from the field in Port Sudan were investigated by monitoring, scanning, resting, taking off, and walking/running in a wind tunnel. Solitarious locusts that had been propagated in the laboratory for 20 generations were also observed for comparison. In both groups of locusts, insects were significantly more active after sunset and this activity attained peak level at 1-2 hours after dusk. Of the two groups, solitarious locusts collected from the field were significantly more active. In the scotophase, the former traversed distances that were about seven times those covered by laboratory-reared locusts. Overall, the results show that the repertoire of behavioral activities of solitarious locusts is maintained in laboratory-reared insects, albeit at a lower level. The implications of these observations in the behavioral ecology of the desert locust are discussed.
International Nuclear Information System (INIS)
Blomberg, L.G.; Marklund, G.T.
1988-02-01
The influence on the high-latitude ionospheric convection of conductivities associated with upward field-aligned currents is investigated. Potential patterns are calculated from a given distribution of field-aligned currents and a conductivity model. The resulting patterns are shown to be modified considerably by including a coupling term between the conductivity and the field-aligned current in the conductivity model. The clockwise rotation of the entire potential pattern is reduced when the conductivity enhancement coincides with the regions of upward field-aligned current. Also, the electric field within these regions turns out to be rather insensitive to change in the magnitude of the current. In regions of downward current or when the current-dependent conductivity is excluded there is on the other hand an almost linear relationship between current and electric field. Although the particles producing the conductivity enhancement may not be the same as those carrying the major part of the field-aligned current it is clear from observations that there is a positive correlation between upward current conductivity. Therefore, the simple relationship used in this study is believed to reflect rather well the principal features of the current-conductivity coupling, which is of im- portance to the modelling of ionospheric electrodynamics. (With 26 refs.) (authors)
Pattern recognition neural-net by spatial mapping of biology visual field
Lin, Xin; Mori, Masahiko
2000-05-01
The method of spatial mapping in biology vision field is applied to artificial neural networks for pattern recognition. By the coordinate transform that is called the complex-logarithm mapping and Fourier transform, the input images are transformed into scale- rotation- and shift- invariant patterns, and then fed into a multilayer neural network for learning and recognition. The results of computer simulation and an optical experimental system are described.
Benoist, R; Chantre, C; Capdevielle-Dulac, C; Bodet, M; Mougel, F; Calatayud, P A; Dupas, S; Huguet, E; Jeannette, R; Obonyo, J; Odorico, C; Silvain, J F; Le Ru, B; Kaiser, L
2017-12-01
Studying mechanisms that drive host adaptation in parasitoids is crucial for the efficient use of parasitoids in biocontrol programs. Cotesia typhae nov. sp. (Fernández-Triana) (Hymenoptera: Braconidae) is a newly described parasitoid of the Mediterranean corn borer Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Braconidae are known for their domesticated bracovirus, which is injected with eggs in the host larva to overcome its resistance. In this context, we compared reproductive success traits of four Kenyan strains of C. typhae on a French and a Kenyan populations of its host. Differences were found between the four strains and the two most contrasted ones were studied more thoroughly on the French host population. Parasitoid offspring size was correlated with parasitism success and the expression of bracovirus virulence genes (CrV1 and Cystatin) in the host larva after parasitism. Hybrids between these two parasitoid strains showed phenotype and gene expression profiles similar to the most successful parental strain, suggesting the involvement of dominant alleles in the reproductive traits. Ovary dissections revealed that the most successful strain injected more eggs in a single host larva than the less successful one, despite an equal initial ovocyte number in ovaries. It can be expected that the amount of viral particles increase with the number of eggs injected. The ability to bypass the resistance of the allopatric host may in consequence be related to the oviposition behaviour (eggs allocation). The influence of the number of injected eggs on parasitism success and on virulence gene expression was evaluated by oviposition interruption experiments.
Pereira, R A; Morais, M M; Nascimento, F S; Bego, L R
2009-01-01
The cell provisioning and oviposition process (POP) is a unique characteristic of stingless bees (Meliponini), in which coordinated interactions between workers and queen regulate the filling of brood cells with larval resources and subsequent egg laying. Environmental conditions seem to regulate reproduction in stingless bees; however, little is known about how the amount of food affects quantitative sequences of the process. We examined intrinsic variables by comparing three colonies in distinct conditions (strong, intermediate and weak state). We predicted that some of these variables are correlated with temporal events of POP in Melipona scutellaris colonies. The results demonstrated that the strong colony had shorter periods of POP.
Directory of Open Access Journals (Sweden)
Simone Pascucci
2018-04-01
Full Text Available The recognition of spatial patterns within agricultural fields, presenting similar yield potential areas, stable through time, is very important for optimizing agricultural practices. This study proposes the evaluation of different clustering methodologies applied to multispectral satellite time series for retrieving temporally stable (constant patterns in agricultural fields, related to within-field yield spatial distribution. The ability of different clustering procedures for the recognition and mapping of constant patterns in fields of cereal crops was assessed. Crop vigor patterns, considered to be related to soils characteristics, and possibly indicative of yield potential, were derived by applying the different clustering algorithms to time series of Landsat images acquired on 94 agricultural fields near Rome (Italy. Two different approaches were applied and validated using Landsat 7 and 8 archived imagery. The first approach automatically extracts and calculates for each field of interest (FOI the Normalized Difference Vegetation Index (NDVI, then exploits the standard K-means clustering algorithm to derive constant patterns at the field level. The second approach applies novel clustering procedures directly to spectral reflectance time series, in particular: (1 standard K-means; (2 functional K-means; (3 multivariate functional principal components clustering analysis; (4 hierarchical clustering. The different approaches were validated through cluster accuracy estimates on a reference set of FOIs for which yield maps were available for some years. Results show that multivariate functional principal components clustering, with an a priori determination of the optimal number of classes for each FOI, provides a better accuracy than those of standard clustering algorithms. The proposed novel functional clustering methodologies are effective and efficient for constant pattern retrieval and can be used for a sustainable management of
International Nuclear Information System (INIS)
Liu Xiaohui; Wang Huasong; Song Jiaxiang
1999-12-01
The transmission of sperm by unirradiated and irradiated cotton bollworm, Helicoverpa armigera, was studied by live dissection of the female immediately after the initiation of mating. In cotton bollworm the sperm transfer was a rather complex process. In fact, the unirradiated male failed to transfer sperm in about 19% of their matings. After being irradiated with 250 Gy and 400 Gy, the aberrations of sperm transmission were about 21% and 50% respectively. The failure of spermatophore 'cap' location was an important reason of sperm transmission aberrations. When female mated to high-dose-irradiated males, its oviposition response appeared abnormal
Oviposition responses of Aedes mosquitoes to bacterial isolates from attractive bamboo infusions.
Ponnusamy, Loganathan; Schal, Coby; Wesson, Dawn M; Arellano, Consuelo; Apperson, Charles S
2015-09-23
The mosquitoes Aedes aegypti and Aedes albopictus are vectors of pathogenic viruses that cause major human illnesses including dengue, yellow fever and chikungunya. Both mosquito species are expanding their geographic distributions and now occur worldwide in temperate and tropical climates. Collection of eggs in oviposition traps (ovitraps) is commonly used for monitoring and surveillance of container-inhabiting Aedes populations by public health agencies charged with managing mosquito-transmitted illness. Addition of an organic infusion in these traps increases the number of eggs deposited. Gravid females are guided to ovitraps by volatile chemicals produced from the breakdown of organic matter by microbes. We previously isolated and cultured 14 species of bacteria from attractive experimental infusions, made from the senescent leaves of canebrake bamboo (Arundinaria gigantea). Cultures were grown for 24 h at 28 °C with constant shaking (120 rpm) and cell densities were determined with a hemocytometer. Behavioral responses to single bacterial isolates and to a mix of isolates at different cell densities were evaluated using two-choice sticky-screen bioassay methods with gravid Ae. aegypti and Ae. albopictus. In behavioral assays of a mix of 14 bacterial isolates, significantly greater attraction responses were exhibited by Ae. aegypti and Ae. albopictus to bacterial densities of 10(7) and 10(8) cells/mL than to the control medium. When we tested single bacterial isolates, seven isolates (B1, B2, B3, B5, B12, B13 and B14) were significantly attractive to Ae. aegypti, and six isolates (B1, B5, B7, B10, B13 and B14) significantly attracted Ae. albopictus. Among all the isolates tested at three different cell densities, bacterial isolates B1, B5, B13 and B14 were highly attractive to both Aedes species. Our results show that at specific cell densities, some bacteria significantly influence the attraction of gravid Ae. aegypti and Ae. albopictus females to
Wang, Bo; Wang, Xiaodong; Etay, Jacqueline; Na, Xianzhao; Zhang, Xinde; Fautrelle, Yves
2016-04-01
In this study, an Archimedean helical permanent magnetic field was constructed and its driving effects on liquid metal were examined. A magnetic stirrer was constructed using a series of arc-like magnets. The helical distribution of its magnetic field, which was confirmed via Gauss probe measurements and numerical simulations, can be considered a combination of rotating and traveling magnetic fields. The characteristics of the flow patterns, particularly the transitions between the meridian secondary flow (two vortices) and the global axial flow (one vortex), driven by this magnetic field were quantitatively measured using ultrasonic Doppler velocimetry. The transient and modulated flow behaviors will be presented in a companion article. The D/ H dimension ratio was used to characterize the transitions of these two flow patterns. The results demonstrated that the flow patterns depend on not only the intrinsic structure of the magnetic field, e.g., the helix lead angle, but also the performance parameters, e.g., the dimensional ratio of the liquid bulk. The notable opposing roles of these two flow patterns in the improvement of macrosegregations when imposing such magnetic fields near the solidifying front were qualitatively addressed.
Significance of bacteria in oviposition and larval development of the sand fly Lutzomyia longipalpis
2012-01-01
Background Microbial ecology of phlebotomine sand flies is not well understood although bacteria likely play an important role in the sand fly biology and vector capacity for Leishmania parasites. In this study, we assessed the significance of the microbial community of rabbit feces in oviposition and larval development of Lutzomyia longipalpis as well as bacterial colonization of the gut of freshly emerged flies. Methods Sterile (by autoclaving) and non-sterile (control) rabbit feces were used in the two-choice assay to determine their oviposition attractiveness to sand fly females. Bacteria were identified by amplification and sequencing of the 16S rRNA gene with universal eubacterial primers. Sterile, control (non-sterile), and sterilized and inoculated rabbit feces were used to assess the significance of bacteria in L. longipalpis development. Newly emerged adult flies were surface-sterilized and screened for the bacterial population size and diversity by the culturing approach. The digestive tract of L4 sterile and control larvae was incubated with Phalloidin to visualize muscle tissues and DAPI to visualize nuclei. Results Two-choice behavioural assays revealed a great preference of L. longipalpis to lay eggs on rabbit feces with an active complex bacterial community (control) (85.8 % of eggs) in comparison to that of sterile (autoclaved) rabbit feces (14.2 %). Bioassays demonstrated that L. longipalpis larvae can develop in sterile rabbit feces although development time to adult stage was greatly extended (47 days) and survival of larvae was significantly lower (77.8 %) compared to that of larvae developing in the control rabbit feces (32 days and 91.7 %). Larval survival on sterilized rabbit feces inoculated with the individual bacterial isolates originating from this substrate varied greatly depending on a bacterial strain. Rhizobium radiobacter supported larval development to adult stage into the greatest extent (39 days, 88.0 %) in
Interfacial patterns in magnetorheological fluids: Azimuthal field-induced structures.
Dias, Eduardo O; Lira, Sérgio A; Miranda, José A
2015-08-01
Despite their practical and academic relevance, studies of interfacial pattern formation in confined magnetorheological (MR) fluids have been largely overlooked in the literature. In this work, we present a contribution to this soft matter research topic and investigate the emergence of interfacial instabilities when an inviscid, initially circular bubble of a Newtonian fluid is surrounded by a MR fluid in a Hele-Shaw cell apparatus. An externally applied, in-plane azimuthal magnetic field produced by a current-carrying wire induces interfacial disturbances at the two-fluid interface, and pattern-forming structures arise. Linear stability analysis, weakly nonlinear theory, and a vortex sheet approach are used to access early linear and intermediate nonlinear time regimes, as well as to determine stationary interfacial shapes at fully nonlinear stages.
International Nuclear Information System (INIS)
Gamon, John A; Kershaw, G Peter; Williamson, Scott; Hik, David S
2012-01-01
Recent observations suggest that while some arctic landscapes are undergoing rapid change, others are apparently more resilient. In this study, we related surface cover and energy balance to microtopography in a degraded polygonal peat plateau (baydjarakh field) near Churchill, Manitoba in mid-summer 2010. The landscape consists of remnant high-centered polygons divided by troughs of varying widths. Historical aerial photos indicate these topographical features have been stable for over 80 years. Our goal was to explore patterns that might explain the apparent stability of this landscape over this time period and to evaluate remote sensing methods for characterizing microtopographic patterns that might resist change in the face of climate warming. Summertime surface albedo measurements were combined with several years of winter snow depth, snow heat flux, summer thaw depth and annual surface temperature, all of which had striking contrasts between wet troughs and high polygon centers. Measurements of albedo and the snowpack heat transfer coefficient were lowest for wet troughs (areas of standing water) dominated by graminoids, and were significantly higher for high polygon centers, dominated by dwarf shrubs and lichens. Snow depth, surface temperature and thaw depth were all significantly higher for wet troughs than high polygon centers. Together these patterns of cover and energy balance associated with microtopographic variation can contribute to the stability of this landscape through differential heat transfer and storage. We hypothesize that local thermal feedback effects, involving greater heat trapping in the troughs than on the baydjarakh tops, and effective insulation on the baydjarakh edges, have ensured landscape stability over most of the past century. These results suggest that high-resolution remote sensing, combined with detailed field monitoring, could provide insights into the dynamics or stability of arctic landscapes, where cover often varies
Is Field of Study or Location Associated with College Students' Snacking Patterns?
Directory of Open Access Journals (Sweden)
Laura H. McArthur
2012-01-01
Full Text Available Objective. To compare on- and off-campus snacking patterns among college students pursuing degrees in health-related fields (HRFs and nonhealth-related fields (NHRFs. Materials and Methods. Snack frequency questionnaire, scales measuring barriers, self-efficacy, and stage of change for healthy snacking, and a snack knowledge test (SKT. Participants. 513 students, 46% HRFs, and 54% NHRFs. The students' mean±SD BMI was 24.1±4.3 kg/m2 (range 14.6 to 43.8, and 32.2% were overweight/obese. Results. Softdrinks (on-campus, lowfat milk (off-campus, and sports drinks were popular among HRFs and NHRFs. Cost and availability were barriers to healthy snacking, students felt least confident to choose healthy snacks when emotionally upset, and 75% (65% of HRFs (NHRFs self-classified in the action stage of change for healthy snacking. The HRFs scored higher on the SKT. Conclusions. Neither location nor field of study strongly influenced snacking patterns, which featured few high-fiber foods.
Influence des engrais de type NPK sur l’oviposition d’Aedes aegypti
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Darriet F.
2008-03-01
Full Text Available Les engrais sont des associations de minéraux destinées à apporter aux plantes des compléments nutritifs nécessaires à leur croissance. Les engrais modernes de type NPK combinent les trois éléments de base que sont l’azote (N, le phosphore (P et le potassium (K. Dans cette étude de laboratoire réalisée dans des tunnels expérimentaux, nous avons étudié l’influence de solutions aqueuses contenant différentes concentrations en engrais NPK sur l’oviposition de femelles d’Aedes aegypti. Les résultats ont montré que les solutions contenant les concentrations en NK = 17-33 mg/l et P = 23-47 mg/l attiraient significativement plus de femelles gravides que l’eau osmosée seule (P 0,05. Ces résultats suggèrent que certaines teneurs en engrais NPK peuvent influencer le comportement de ponte du moustique Ae. aegypti.
Pilling evaluation of patterned fabrics based on a gradient field method
Czech Academy of Sciences Publication Activity Database
Techniková, L.; Tunák, M.; Janáček, Jiří
2016-01-01
Roč. 41, č. 1 (2016), s. 97-101 ISSN 0971-0426 Institutional support: RVO:67985823 Keywords : 3D surface reconstruction * fabric pilling * gradient field method * patterned fabric * pills detection Subject RIV: JS - Reliability ; Quality Management, Testing Impact factor: 0.430, year: 2016
PLD synthesis of GaN nanowires and nanodots on patterned catalyst surface for field emission study
Energy Technology Data Exchange (ETDEWEB)
Ng, D.K.T.; Hong, M.H. [National University of Singapore (Singapore). Department of Electrical and Computer Engineering; Data Storage Institute, Singapore (Singapore); Tan, L.S. [National University of Singapore (Singapore). Department of Electrical and Computer Engineering; Zhu, Y.W.; Sow, C.H. [National University of Singapore (Singapore). Nanoscience and Nanotechnology Initiative; National University of Singapore (Singapore). Department of Physics
2008-11-15
Patterned gallium nitride nanowires and nanodots have been grown on n-Si(100) substrates by pulsed laser deposition. The nanostructures are patterned using a physical mask, resulting in regions of nanowire growth of different densities. The field emission (FE) characteristics of the patterned gallium nitride nanowires show a turn-on field of 9.06 V/{mu}m to achieve a current density of 0.01 mA/cm{sup 2} and an enhanced field emission current density as high as 0.156 mA/cm{sup 2} at an applied field of 11 V/{mu}m. Comparing the peak FE current densities of both the nanowires and nanodots, the peak FE current density of nanowires is around 700 times higher than that of the peak FE current density of nanodots since nanodots have a lower aspect ratio compared to nanowires. The field emission results indicate that, besides density difference, crystalline quality as well as the low electron affinity of gallium nitride, high aspect ratio of gallium nitride nanostructures will greatly enhance their field emission properties. (orig.)
Xiang, Ying; Zhou, Meng-jie; Xu, Ming-Ya; Salamon, Péter; Éber, Nándor; Buka, Ágnes
2015-04-01
Electric-field-induced patterns of diverse morphology have been observed over a wide frequency range in a recently synthesized bent-core nematic (BCN) liquid crystal. At low frequencies (up to ∼25 Hz), the BCN exhibited unusual polarity-dependent patterns. When the amplitude of the ac field was enhanced, these two time-asymmetrical patterns turned into time-symmetrical prewavylike stripes. At ac frequencies in the middle-frequency range (∼50-3000 Hz), zigzag patterns were detected whose obliqueness varied with the frequency. Finally, if the frequency was increased above 3 kHz, the zigzag pattern was replaced by another, prewavylike pattern, whose threshold voltage depended on the frequency; however, the wave vector did not. For a more complete characterization, material parameters such as elastic constants, dielectric permittivities, and the anisotropy of the diamagnetic susceptibility were also determined.
Cocco, Arturo; Muscas, Enrico; Mura, Alessandra; Iodice, Andrea; Savino, Francesco; Lentini, Andrea
2018-05-08
Although mating disruption is increasingly being used to control the worldwide grapevine pest vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), its mode of action remains unclear. A three-year field experiment was carried out to investigate the effects of mating disruption on the development and reproduction of the vine mealybug. The influence of mating disruption applied over consecutive years on the pest population density was also evaluated. The percentage of ovipositing females was significantly reduced in disrupted plots by 18.8-66.2%, depending on the year. The absence of ovipositing females in disrupted plots in the autumn of the second and third year indicates the effectiveness of mating disruption throughout the whole growing season. Mating disruption consistently prolonged the pre-oviposition period in all years by up to 12.5 days. Our findings provide new insights into the mechanisms underlying the pheromone-based control of the vine mealybug and indicate that the reduction of the pest population density is due to both a decrease and delay in female mating. In addition, the population density of vine mealybugs under mating disruption decreased over years, indicating that consecutive applications of this control strategy would significantly increase the effectiveness of controlling the vine mealybug by mating disruption. This article is protected by copyright. All rights reserved.
Short-range dynamics and prediction of mesoscale flow patterns in the MISTRAL field experiment
Energy Technology Data Exchange (ETDEWEB)
Weber, R.O.; Kaufmann, P.; Talkner, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1997-06-01
In a limited area of about 50 km by 50 km with complex topography, wind measurements on a dense network were performed during the MISTRAL field experiment in 1991-1992. From these data the characteristic wind fields were identified by an automated classification method. The dynamics of the resulting twelve typical regional flow patterns is studied. It is discussed how transitions between the flow patterns take place and how well the transition probabilities can be described in the framework of a Markov model. Guided by this discussion, a variety of prediction models were tested which allow a short-term forecast of the flow pattern type. It is found that a prediction model which uses forecast information from the synoptic scale has the best forecast skill. (author) 2 figs., 7 refs.
Spindola, Aline F; Zheng, Le; Tomberlin, Jeffery K; Thyssen, Patricia J
2017-03-01
The present study aimed to determine if the presence of immatures of the invasive blow fly species Chrysomya albiceps (Wiedemann) influences the adult behavior of the native species Lucilia eximia (Wiedemann) in Brazil. The level of attraction and oviposition by the native species was assessed in a dual-choice assay. The evaluation was based on sex and stage of ovarian development of L. eximia adults to a resource not colonized (NCR) or colonized (RPC) with eggs, different instars, or densities of C. albiceps. A significant difference in attraction was observed based on sex and stages of ovarian development. Males and nongravid females were more attracted to RPC, whereas gravid females preferred NCR. Moreover, males exhibited the lowest response in all assays among the three sex categories examined. In general, adults preferably oviposited on NCR rather than RPC. Also, between the eggs and second instar treatments, L. eximia laid more eggs on RPC with eggs than second instars (predatory stage). Lucilia eximia attraction to second-instar C. albiceps at different densities was marginally significant. Overall, results indicate the invasive species, C. albiceps, is impacting the behavior of the native blow fly, L. eximia, with regards to its attraction and colonization of vertebrate carrion, which could explain why native blow fly populations have significantly decreased since the introduction of C. albiceps. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Numerical Study of Flow Motion and Patterns Driven by a Rotating Permanent Helical Magnetic Field
Yang, Wenzhi; Wang, Xiaodong; Wang, Bo; Baltaretu, Florin; Etay, Jacqueline; Fautrelle, Yves
2016-10-01
Liquid metal magnetohydrodynamic flow driven by a rotating permanent helical magnetic field in a cylindrical container is numerically studied. A three-dimensional numerical simulation provides insight into the visualization of the physical fields, including the magnetic field, the Lorentz force density, and the flow structures, especially the flow patterns in the meridional plane. Because the screen parameter is sufficiently small, the model is decoupled into electromagnetic and hydrodynamic components. Two flow patterns in the meridional plane, i.e., the global flow and the secondary flow, are discovered and the impact of several system parameters on their transition is investigated. Finally, a verifying model is used for comparison with the previous experiment.
Rapidity-density patterns for events in a stochastic-field multiparticle theory
International Nuclear Information System (INIS)
Arnold, R.C.
1976-02-01
Typical-event rapidity distributions expected at energies of a few TeV are calculated in a stochastic-field multiparticle production theory. Short range rapidity correlations with characteristics of a Van der Waals fluid give rise to ''domain'' patterns in rapidity density, which have the appearance of clusters separated by rapidity gaps
Directory of Open Access Journals (Sweden)
Kees van Achterberg
2011-08-01
Full Text Available The oviposition behaviour of four ant parasitoids was observed and filmed for the first time. The movies are available from YouTube (search for Elasmosoma, Hybrizon, Kollasmosoma and Neoneurus. Two of the observed species (Neoneurus vesculus sp. n. and Kollasmosoma sentum sp. n. are new to science. A third species (Neoneurus recticalcar sp. n. is described from Slovakia and Norway. Keys to the Palaearctic species of the genera Neoneurus and Kollasmosoma are added.
STECH, 3(3), S/NO 12, SEPTEMBER, 2014
African Journals Online (AJOL)
DR Nneka
2014-09-12
Sep 12, 2014 ... Observations on the Biology of Callosobruchus Maculatus. (Fab.) (Coleoptera: Bruchidae) under Ambient Laboratory ... carried out under ambient laboratory conditions. Pattern of oviposition, female adult longevity and F1 .... Effect of cowpea seed coat texture on the oviposition and progeny development of ...
Decoding complex flow-field patterns in visual working memory.
Christophel, Thomas B; Haynes, John-Dylan
2014-05-01
There has been a long history of research on visual working memory. Whereas early studies have focused on the role of lateral prefrontal cortex in the storage of sensory information, this has been challenged by research in humans that has directly assessed the encoding of perceptual contents, pointing towards a role of visual and parietal regions during storage. In a previous study we used pattern classification to investigate the storage of complex visual color patterns across delay periods. This revealed coding of such contents in early visual and parietal brain regions. Here we aim to investigate whether the involvement of visual and parietal cortex is also observable for other types of complex, visuo-spatial pattern stimuli. Specifically, we used a combination of fMRI and multivariate classification to investigate the retention of complex flow-field stimuli defined by the spatial patterning of motion trajectories of random dots. Subjects were trained to memorize the precise spatial layout of these stimuli and to retain this information during an extended delay. We used a multivariate decoding approach to identify brain regions where spatial patterns of activity encoded the memorized stimuli. Content-specific memory signals were observable in motion sensitive visual area MT+ and in posterior parietal cortex that might encode spatial information in a modality independent manner. Interestingly, we also found information about the memorized visual stimulus in somatosensory cortex, suggesting a potential crossmodal contribution to memory. Our findings thus indicate that working memory storage of visual percepts might be distributed across unimodal, multimodal and even crossmodal brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.
Wang, L.; Coccia, M.
2015-01-01
Frame and Carpenter (1979) analysed the pattern of international research collaboration among scientific fields in 1970s. Starting from this pioneering work, this paper investigates international collaborations over 1997-2012 and compares the critical results with earlier studies to detect the
Directory of Open Access Journals (Sweden)
Elsa Gilardón
2001-03-01
Full Text Available Os tricomas glandulares presentes nas folhas e ramos das plantas do gênero Lycopersicon são responsáveis pela secreção de metabólitos de diferentes naturezas. A presença de alguns desses compostos tem sido associada à resistência do tomate a diferentes insetos. A traça-do-tomateiro, Tuta absoluta (Meyrick, é uma das pragas mais nocivas da América do Sul. O adulto oviposita sobre as folhas do tomate e suas larvas abrem galerias no mesófilo das folhas, ramos, flores e frutos. As espécies silvestres do tomate conservam a capacidade de biossintetizar compostos químicos que lhes conferem resistência a esta praga. No presente trabalho, foi avaliada a preferência para oviposição desse inseto sobre folhas com e sem tricomas glandulares de L. esculentum (Mill. cv. Uco Plata, suscetível, e de L. hirsutum f. glabratum (Mull. PI 134417, espécie silvestre afim ao tomate, e resistente à traça. Os resultados sugerem que as fêmeas ovipositam indistintamente sobre as folhas de ambas espécies, independentemente da presença, ou não, dos tricomas glandulares. E a presença destes e de seus exsudatos não têm efeito inibidor na oviposição do inseto.In the genus Lycopersicon, different metabolites are secreted by the glandular trichomes of leaves and stems. These compounds have been associated to different tomato pests resistance. The South American tomato pinworm, Tuta absoluta (Meyrick, is one of the most harmful pests in South America. The females oviposit on tomato leaves and the larvae mine the leaf mesophyl, stems, flowers and fruits. Some wild accessions of Lycopersicon keep their capacity to synthesize allelochemicals that protect them from the pest. In this paper a comparison was made between the tomato pinworm oviposition on leaves with and without trichomes of L. esculentum (Mill. cv. Uco Plata, a susceptible cultivar, and L. hirsutum f. glabratum (Mull. PI 134417, a resistant wild accession. Results suggest that the female
Directory of Open Access Journals (Sweden)
Rizatus Shofiyati1
2012-10-01
Full Text Available This paper investigates the use of multi spectral satellite data for cropping pattern monitoring in paddy field. The southern coastal of Citarum watershed, West Java Province was selected as study sites. The analysis used in this study is identifying crop pattern based on growth stages of wetland paddy and other crops by investi-gating the characteristic of Normalized Differen-ce Vegetation Indices (NDVI and Wetness of Tasseled Cap Transformation (TCT derived from 14 scenes of Landsat TM date 1988 to 2001. In general, the phenological of growth stages of wetland paddy can be used to distinguish with other seasonal crops. The research results indicate that multi spectral satellite data has a great potential for identi-fication and monitoring cropping pattern in paddy field. Specific character of NDVI and Wetness can also produce a map of cropping pattern in paddy field that is useful to monitor agricultural land condition. The cropping pattern can also be used to estimate irrigation water needed of paddy field in the area. Expected implication of the information obtained from this analysis is useful for guiding more appropriate planning and better agricultural management.
New Subarray Readout Patterns for the ACS Wide Field Channel
Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.
2017-04-01
At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.
Sun, Qi; Fu, Shujun
2017-09-20
Fringe orientation is an important feature of fringe patterns and has a wide range of applications such as guiding fringe pattern filtering, phase unwrapping, and abstraction. Estimating fringe orientation is a basic task for subsequent processing of fringe patterns. However, various noise, singular and obscure points, and orientation data degeneration lead to inaccurate calculations of fringe orientation. Thus, to deepen the understanding of orientation estimation and to better guide orientation estimation in fringe pattern processing, some advanced gradient-field-based orientation estimation methods are compared and analyzed. At the same time, following the ideas of smoothing regularization and computing of bigger gradient fields, a regularized singular-value decomposition (RSVD) technique is proposed for fringe orientation estimation. To compare the performance of these gradient-field-based methods, quantitative results and visual effect maps of orientation estimation are given on simulated and real fringe patterns that demonstrate that the RSVD produces the best estimation results at a cost of relatively less time.
Cho, Nahye; Kang, Youngok
2018-05-01
A numerous log data in addition to user input data are being generated as mobile and web users continue to increase recently, and the studies in order to explore the patterns and meanings of various movement activities by making use of these log data are also rising rapidly. On the other hand, in the field of education, people have recognized the importance of field trip as the creative education is highlighted. Also, the examples which utilize the mobile devices in the field trip in accordance to the development of information technology are growing. In this study, we try to explore the patterns of student's activity by visualizing the log data generated from high school students' field trip with mobile device.
Amarillo-Suárez, A; Repizo, A; Robles, J; Diaz, J; Bustamante, S
2017-08-01
The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.
Very high-accuracy calibration of radiation pattern and gain of a near-field probe
DEFF Research Database (Denmark)
Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav
2014-01-01
In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission of the Europ...
Toth, Kristof; Hu, Hanqiong; Choo, Youngwoo; Loewenberg, Michael; Osuji, Chinedum
The delivery of sub-micron droplets of dilute polymer solutions to a heated substrate by electrospray deposition (ESD) enables precisely controlled and continuous growth of block copolymer (BCP) thin films. Here we explore patterned deposition of BCP films by spatially varying the electric field at the substrate using an underlying charged grid, as well as film growth kinetics. Numerical analysis was performed to examine pattern fidelity by considering the trajectories of charged droplets during flight through imposed periodic field variations in the vicinity of the substrate. Our work uncovered an unexpected modality for improving the resolution of the patterning process via stronger field focusing through the use of a second oppositely charged grid beneath a primary focusing array, with an increase in highly localized droplet deposition on the intersecting nodes of the grid. Substrate coverage kinetics are considered for homopolymer deposition in the context of simple kinetic models incorporating temperature and molecular weight dependence of diffusivity. By contrast, film coverage kinetics for block copolymer depositions are additionally convoluted with preferential wetting and thickness-periodicity commensurability effects. NSF GRFP.
Ahern, Robert G; Frank, Steven D; Raupp, Michael J
2005-12-01
Insecticides are traditionally used to control periodical cicadas (Homoptera: Cicadidae) and to reduce associated injury caused by oviposition. However, research has shown that conventional insecticides have low or variable season-long efficacy in reducing injury caused by cicadas. New systemic neonicotinoid insecticides provide excellent levels of control against a variety of sucking insects. We compared the efficacy of a neonicotinoid insecticide, imidacloprid, and a nonchemical control measure, netting, to reduce cicada injury. Netted trees sustained very little injury, whereas unprotected trees were heavily damaged. Fewer eggnests, scars, and flags were observed on trees treated with imidacloprid compared with unprotected trees; however, the hatching of cicada eggs was unaffected by imidacloprid.
Biogeographic patterns of microbial communities from different oil-contaminated fields in China
Energy Technology Data Exchange (ETDEWEB)
Liang, Yuting; Li, Guanghe [School of Environment, Tsinghua University (China); Zhou, Ji zhong [Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma (United States)], email: jzhou@ou.edu
2011-07-01
Some striking biological challenges of the 21st century include linking biodiversity to ecosystem functions, information scaling, and linking genomics to ecology. This paper discusses the biogeographic patterns of microbial communities from various oil-contaminated fields in China. Two kinds of high throughput approaches are used, open format and closed format. Key differences between them are outlined. The GeoChip, or functional gene array (FGA) approach is presented. This is a high throughput tool for linking community structure to functions. Its main advantages are its high resolution and detecting functions. This approach was applied to soils, bioreactors and ground waters, among others. Issues related to specificity, sensitivity and quantification are listed. An overview of the microarray analysis is given. This is applied to the BP oil spill. 100 samples were chosen from representative oil fields to study the biogeographic patterns of microbial communities in China. The complete study is presented with the results.
Sharma, Abhinav; Tiwari, Vijeet; Kumar, Vineet; Mandal, Tapas Kumar; Bandyopadhyay, Dipankar
2014-10-01
Strategic application of external electrostatic field on a pressure-driven two-phase flow inside a microchannel can transform the stratified or slug flow patterns into droplets. The localized electrohydrodynamic stress at the interface of the immiscible liquids can engender a liquid-dielectrophoretic deformation, which disrupts the balance of the viscous, capillary, and inertial forces of a pressure-driven flow to engender such flow morphologies. Interestingly, the size, shape, and frequency of the droplets can be tuned by varying the field intensity, location of the electric field, surface properties of the channel or fluids, viscosity ratio of the fluids, and the flow ratio of the phases. Higher field intensity with lower interfacial tension is found to facilitate the oil droplet formation with a higher throughput inside the hydrophilic microchannels. The method is successful in breaking down the regular pressure-driven flow patterns even when the fluid inlets are exchanged in the microchannel. The simulations identify the conditions to develop interesting flow morphologies, such as (i) an array of miniaturized spherical or hemispherical or elongated oil drops in continuous water phase, (ii) "oil-in-water" microemulsion with varying size and shape of oil droplets. The results reported can be of significance in improving the efficiency of multiphase microreactors where the flow patterns composed of droplets are preferred because of the availability of higher interfacial area for reactions or heat and mass exchange. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Distribution pattern assessment of a dual-purpose disc agrochemical applicator for field crops
Directory of Open Access Journals (Sweden)
M. S. Abubakar
2012-08-01
Full Text Available A dual-purpose disc agrochemical applicator for field crops was developed to boost agricultural mechanization in crop production and also to overcome the safety concern of hazardous spray drift during agrochemical application by the field crop farmers. The dual purpose agrochemical applicator was mounted on a high clearance tractor and tested with respect to the granular fertilizer distribution patterns uniformity/liquid chemical uniformity of droplet sizes in spraying of the agrochemical. Results for NPK granular chemical indicated that, at low (50 kg/ha and high (150 kg/ha application rates with 550 rpm disc speed, distribution patterns skewed to the left whereas the distribution pattern at medium (100 kg/ha application rates was good flattop. Also at high application rate with 1000 rpm disc speed, mean distribution pattern became poor (W-shape. For the liquid chemical herbicide HC 48 amine liquid, the mean values of volume median diameter (VMD and number median diameter (NMD were 108 µm and 80 µm at 90 lt/ha application rate at 5000 rpm rotary disc speed, and also 344 and 222 µm at 30 lt/ha application rate with 2000 rpm rotary disc speed. The mean values of coefficient of uniformity for droplet sizes expressed as VMD/NMD found in this study were in the range of 1.35 to 1.55 for HC amine 48 liquid chemical.
Geomagnetic field, global pattern
Macmillan, Susan
2011-01-01
The geomagnetic field is generated in the fluid outer core region of the Earth by electrical currents flowing in the slowly moving molten iron. In addition to sources in the Earth’s core, the geomagnetic field observable on the Earth’s surface has sources in the crust and in the ionosphere and magnetosphere. The signal from the core dominates, accounting for over 95% of the field at the Earth’s surface. The geomagnetic field varies on a range of scales, both temporal and spatial; the...
Effect of a nighttime magnetic field exposure on sleep patterns in young women.
Tworoger, Shelley S; Davis, Scott; Emerson, Scott S; Mirick, Dana K; Lentz, Martha J; McTiernan, Anne
2004-08-01
Since poor sleep quality is associated with multiple health problems, it is important to understand factors that may affect sleep patterns. The purpose of this study was to determine the effect of a continuous, 60-Hz, nighttime magnetic field exposure on sleep outcomes in young women sleeping at home. The study was a randomized crossover trial, comparing intervention (0.5-1.0 micro T above ambient levels) with ambient magnetic field levels, during two 5-night measurement periods. Subjects lived in the Seattle, Washington, area and were 20-40 years of age, had regular menstrual cycles, were not taking oral contraceptives, and had not breastfed or been pregnant during the previous year. The study was conducted between March and September of 2001. Sleep outcomes were measured via actigraphy. The range of magnetic field exposure was 0.001-0.50 micro T during the ambient period and 0.41-1.21 micro T during the intervention period. Sleep outcomes were not significantly different between the intervention and the ambient measurement periods. The intervention magnetic field had no effect on sleep patterns, suggesting that this exposure may not be an important factor in predicting sleep of young women who sleep at home.
Conditional Random Fields for Pattern Recognition Applied to Structured Data
Directory of Open Access Journals (Sweden)
Tom Burr
2015-07-01
Full Text Available Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is “manmade” (such as a building or “natural” (such as a tree. Suppose the label for a pixel patch is “manmade”; if the label for a nearby pixel patch is then more likely to be “manmade” there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X is difficult because features between parts of the model are often correlated. Therefore, conditional random fields (CRFs model structured data using the conditional distribution P(Y|X = x, without specifying a model for P(X, and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches in the output domain. Second, we identify research topics and present numerical examples.
Kent, Clement; Azanchi, Reza; Smith, Ben; Chu, Adrienne; Levine, Joel
2007-01-01
Drosophila Cuticular Hydrocarbons (CH) influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD) conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions. PMID:17896002
Directory of Open Access Journals (Sweden)
Clement Kent
Full Text Available Drosophila Cuticular Hydrocarbons (CH influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions.
Induced Light Emission from Quantum Dots: The Directional Near-Field Pattern
DEFF Research Database (Denmark)
Iezhokin, Igor; Keller, Ole; Lozovski, Valeri
2010-01-01
The optical Lippmann-Schwinger equation, supplemented by the microscopic conductivity tensor, is used to establish a near-field radiation theory for a mesoscopic particle. The present theory deviates from previous ones in that it allows one to take into account the finite size of the particle...... in a selfconsistent local-field calculation. The main result of the basic theory is illustrated by a number of numerical calculations on box-shaped quantum dots keeping only two optically mobile electrons. Particular attendance is paid to the distance and angular dependences of the near-field radiation pattern When...... the distance between the particle and observation point exceeds just a few times the linear dimension of the particle the directional radiation diagrams all become qualitatively identical to those of an electric point-dipole radiator The result of the present theory may be of particular interest for studies...
Confinement factor, near and far field patterns in InGaN MQW laser diodes
Martín, J.; Sánchez, M.
2005-07-01
In this work the influence of the QW number in the active region on spectral characteristics in InGaN multi quamtun well lasers is analyzed. A comparison between the abrupt index step structure (Step) and a graded-index structure (GRIN) is done. The effect of the introduction of a p-AlxGa1-xN electron blocking layer, placed above the last InGaN barrier in the Step structure is also analyzed. Calculations of the confinement factor, near and far field patterns were carried out. We found that with the adequate aluminum content in this layer, the confinement factor, near and far field patterns are improved, and values similar to those obtained with GRIN structure can be reached.
Suman, Devi Shankar; Wang, Yi; Faraji, Ary; Williams, Gregory M; Williges, Eric; Gaugler, Randy
2018-04-01
Control of the container-inhabiting mosquito, Aedes albopictus, is difficult using conventional methods due to its selection of cryptic peri-domestic habitats. We evaluated whether autodissemination stations can deliver sufficient pyriproxyfen to sentinel containers to produce significant pupal mortality in different habitats such as competing oviposition sites, peri-domestic habitats, junkyards and tire piles. We also tested how far the pesticide could be transferred over a 200-m range. Autodissemination stations performed effectively for 8-12 weeks under field conditions. Pupal mortality was reduced in sentinel cups with high-competing oviposition habitats (5 versus 20) in isolated plots; however, similar results were not seen in residential areas. Increasing the number of stations per plot (from 1 to 4) enhanced the efficacy. Peri-domestic habitat trials showed the highest pupal mortality (50.4%) and site contamination with pyriproxyfen (82.2%) among the trials. Autodissemination stations were able to contaminate habitats in a junkyard (50.0%) and tire piles (40.2%). Pyriproxyfen was detected in sentinel cups up to 200 m from stations. Detection of pyriproxyfen by residue analysis (0.005-0.741 µg L -1 ) in field samples confirmed the transfer of the insect growth regulator. Autodissemination stations have shown promising potential as a novel pest management tool against container mosquitoes in field trials in different habitats confronted by mosquito control personnel. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
Li, Duo-Jie; Li, Hong-Wei; He, Bin; Wang, Geng-Ming; Cai, Han-Fei; Duan, Shi-Miao; Liu, Jing-Jing; Zhang, Ya-Jun; Cui, Zhen; Jiang, Hao
2016-01-01
To retrospectively analyze the patterns of failure and the treatment effects of involved-field irradiation (IFI) on patients treated with locally advanced esophageal squamous cell carcinoma (ESCC) and to determine whether IFI is practicable in these patients. A total of 79 patients with locally advanced ESCC underwent three dimensional conformal (3D)CRT) or intensity modulated radiotherapy (IMRT) using IFI or elective nodal irradiation (ENI) according to the target volume. The patterns of failure were defined as local/regional, in-field, out)of)field regional lymph node (LN) and distant failure. With a median follow)up of 32.0 months, failures were observed in 66 (83.6%) patients. The cumulative incidence of local/regional failure (55.8 vs 52.8%) and in)field regional lymph node failure (25.6 vs 19.4%) showed no statistically significant difference between the IFI and the ENI group (p=0.526 and 0.215, respectively). Out)of)field nodal relapse rate of only 7.0% was seen in the IFI group. Three)year survival rates for the ENI and IFI group were 22.2 and 18.6%, respectively (p=0.240), and 3)year distant metastasis rates were 27.8 and 32.6%, respectively (p=0.180). The lung V10, V20, V30 and mean lung dose of the ENI group were greater than those of the IFI group, while the mean lung dose and V10 had statistically significant difference. The patterns of failure and survival rates in the IFI group were similar as in the ENI group; the regional recurrence and distant metastasis are the main cause of treatment failure. IFI is feasible for locally advanced ESCC. Further investigation is needed to increase local control and decrease distant metastasis in these patients.
Arya, Mahima; Bhatnagar, Mukul; Ranjan, Mukesh; Mukherjee, Subroto; Nath, Rabinder; Mitra, Anirban
2017-11-01
An analytical model has been developed using a modified Yamaguchi model along with the wavelength dependent plasmon line-width correction. The model has been used to calculate the near-field response of random nanoparticles on the plane surface, elongated and spherical silver nanoparticle arrays supported on ion beam produced ripple patterned templates. The calculated near-field mapping for elongated nanoparticles arrays on the ripple patterned surface shows maximum number of hot-spots with a higher near-field enhancement (NFE) as compared to the spherical nanoparticle arrays and randomly distributed nanoparticles on the plane surface. The results from the simulations show a similar trend for the NFE when compared to the far field reflection spectra. The nature of the wavelength dependent NFE is also found to be in agreement with the observed experimental results from surface enhanced Raman spectroscopy (SERS). The calculated and the measured optical response unambiguously reveal the importance of interparticle gap and ordering, where a high intensity Raman signal is obtained for ordered elongated nanoparticles arrays case as against non-ordered and the aligned configuration of spherical nanoparticles on the rippled surface.
Patterns of resource exploitation in four coexisting globeflower fly species ( Chiastocheta sp.)
Pompanon, François; Pettex, Emeline; Després, Laurence
2006-03-01
Life history and spatio-temporal patterns of resource utilisation were characterised in four Chiastocheta (Diptera: Anthomyiidae) species, whose larvae compete as seed predators on Trollius europaeus fruits. Interspecific co-occurrence was observed in 80% of the resource patches (= Trollius fruits) in the two communities studied. Isolated larvae from all species had a similar food intake, but differed in development time and size at emergence. Different species exhibit contrasting resource exploitation strategies with specific mining patterns and a partial temporal shift. Two species exhibited particularly singular strategies. C. rotundiventris escaped from strong interactions with other species because it was the first species to develop and the only one to exploit the central pith of Trollius fruits. The key role of this species as the main pollinator of the host-plant appears to be a by-product of constraints imposed by occupying a restricted niche. Although the resource is ephemeral due to seed dispersal, C. dentifera, the last species to oviposit, is not disadvantaged because it has a short development time and rapid food intake. The different patterns can partly explain the stability of Chiastocheta communities, but do not prevent competition to occur at high larval densities.
Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures
Energy Technology Data Exchange (ETDEWEB)
Ziętek, Slawomir, E-mail: zietek@agh.edu.pl; Skowroński, Witold; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Ogrodnik, Piotr, E-mail: piotrogr@if.pw.edu.pl [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Stobiecki, Feliks [Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland); Dijken, Sebastiaan van [NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto (Finland); Barnaś, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań (Poland); Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland)
2016-08-15
Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.
Fischer, M. J.
2014-02-01
There are many different methods for investigating the coupling between two climate fields, which are all based on the multivariate regression model. Each different method of solving the multivariate model has its own attractive characteristics, but often the suitability of a particular method for a particular problem is not clear. Continuum regression methods search the solution space between the conventional methods and thus can find regression model subspaces that mix the attractive characteristics of the end-member subspaces. Principal covariates regression is a continuum regression method that is easily applied to climate fields and makes use of two end-members: principal components regression and redundancy analysis. In this study, principal covariates regression is extended to additionally span a third end-member (partial least squares or maximum covariance analysis). The new method, regularized principal covariates regression, has several attractive features including the following: it easily applies to problems in which the response field has missing values or is temporally sparse, it explores a wide range of model spaces, and it seeks a model subspace that will, for a set number of components, have a predictive skill that is the same or better than conventional regression methods. The new method is illustrated by applying it to the problem of predicting the southern Australian winter rainfall anomaly field using the regional atmospheric pressure anomaly field. Regularized principal covariates regression identifies four major coupled patterns in these two fields. The two leading patterns, which explain over half the variance in the rainfall field, are related to the subtropical ridge and features of the zonally asymmetric circulation.
Directory of Open Access Journals (Sweden)
Angelita Anália Carniel Barbosa
2010-06-01
Full Text Available This study aimed to describe the behavior of oviposition traps for Aedes aegypti over time, to compare it with the larval survey and to investigate the association with climatic variables. It was conducted in São José do Rio Preto city, São Paulo. Daily climatic data and fortnightly measurements for oviposition traps and larval infestation were collected from October 2003 to September 2004. Three different periods were identified in the behavior of oviposition traps' positivity and mean number of eggs: increase, plateau and decrease in values. These measurements followed the variation of climatic data from the first and third periods. High correlation was obtained between the positivity and the mean number of eggs. The oviposition traps showed higher capacity to detect the vector than did larval survey. It was observed that the first (October to December and third (May to September periods were considered to be the most suitable to use oviposition traps than larval surveys.O estudo teve como objetivos descrever o comportamento da armadilha de oviposição para Aedes aegypti ao longo do tempo, comparar com a pesquisa larvária e investigar sua associação com variáveis climáticas. O trabalho foi realizado em São José do Rio Preto, São Paulo. Entre outubro de 2003 a setembro de 2004, as armadilhas e a pesquisa larvária forneceram dados quinzenais e foram obtidos dados climáticos. Três períodos distintos foram identificados no comportamento da positividade das armadilhas e no número médio de ovos: aumento, patamar e decréscimo dos valores. Estas medidas acompanharam as variações climáticas. Alta correlação foi obtida entre a positividade e número de ovos. As armadilhas de oviposição apresentam maior capacidade para detectar o vetor do que a pesquisa larvária. Foi observado que o primeiro (outubro a dezembro e terceiro (maio a setembro períodos foram os mais adequados para utilização das armadilhas de oviposição em
Controllable deposition distance of aligned pattern via dual-nozzle near-field electrospinning
Wang, Zhifeng; Chen, Xindu; Zeng, Jun; Liang, Feng; Wu, Peixuan; Wang, Han
2017-03-01
For large area micro/nano pattern printing, multi-nozzle electrohydrodynamic (EHD) printing setup is an efficient method to boost productivity in near-field electrospinning (NFES) process. And controlling EHD multi-jet accurate deposition under the interaction of nozzles and other parameters are crucial concerns during the process. The influence and sensitivity of various parameters such as the needle length, needle spacing, electrode-to-collector distance, voltage etc. on the direct-write patterning performance was investigated by orthogonal experiments with dual-nozzle NFES setup, and then the deposition distance estimated based on a novel model was compared with measurement results and proven. More controllable deposition distance and much denser of aligned naofiber can be achieved by rotating the dual-nozzle setup. This study can be greatly contributed to estimate the deposition distance and helpful to guide the multi-nozzle NFES process to accurate direct-write pattern in manufacturing process in future.
Wang, Jian; Li, Hao; Zou, Haoyang; Wang, Chenmiao; Zhang, Hao; Mano, João F; Song, Wenlong
2017-02-28
Inspired by the rolling of water droplets on lotus leaves, we developed a novel, magnetic field-controlled patterning method for water-soluble proteins and other functional materials on superhydrophobic platforms. This simple method can be used to fabricate biochips and open micro-fluidic devices in a simple way.
Directory of Open Access Journals (Sweden)
Woyke Jerzy
2016-12-01
Full Text Available This paper emphasizes the topics concerning honey bee (Apis mellifera L. mating biology, which have not been described in the recently published book of Koeniger et al. (2014. At the beginning of natural mating, the drone becomes paralyzed. However, the muscles in the abdomen continuously contract shrinking the abdomen till mating has ended and the pair have separated. It is not the queen that ends the nuptial flight. The termination of the nuptial flight is determined by the drone, which fails to remove the mating sign of the previous drone from the sting chamber of the queen. The mating sign originates from two or more drones. The queen also does not determine the age at which she starts oviposition. It is the last drone, which tried to mate, but failed to remove the mating sign of the predecessor, that determines the age that the queen starts oviposition. The book of Koeniger et al. (2014, together with this paper, present the current knowledge of the mating biology of honey bees.
Seiter, Nicholas J; Reay-Jones, Francis P F; Greene, Jeremy K
2013-12-01
The recently introduced plataspid Megacopta cribraria (F.) can infest fields of soybean (Glycine max (L.) Merrill) in the southeastern United States. Grid sampling in four soybean fields was conducted in 2011 and 2012 to study the spatial distribution of M. cribraria adults, nymphs, and egg masses. Peak oviposition typically occurred in early August, while peak levels of adults occurred in mid-late September. The overall sex ratio was slightly biased at 53.1 ± 0.2% (SEM) male. Sweep samples of nymphs were biased toward late instars. All three life stages exhibited a generally aggregated spatial distribution based on Taylor's power law, Iwao's patchiness regression, and spatial analysis by distance indices (SADIE). Interpolation maps of local SADIE aggregation indices showed clusters of adults and nymphs located at field edges, and mean densities of adults were higher in samples taken from field edges than in those taken from field interiors. Adults and nymphs were often spatially associated based on SADIE, indicating spatial stability across life stages.
International Nuclear Information System (INIS)
Oliveira, Lenita J.; Hoffmann-Campo, Clara B.
2007-01-01
Laboratory and greenhouse experiments were carried out to study food and oviposition preference by Phyllophaga cuyabana (Moser) on different plant species as Cajanus cajan L. (pigeon pea), Crotalaria juncea L. (sun hemp), Crotalaria spectabilis Roth (showy crotalaria), Crotalaria ochroleuca G. Don (slenderleaf rattlebox), Glycine max [L.] Merrill (soybean), Gossypium hirsutum L. (cotton), Helianthus annuus L. (sunflower), Stizolobium aterrimum [Mucuna aterrima] Piper and Tracey (velvetbean) and Zea mays L. (mayze). In no-choice experiments, the number of eggs layed in sunflower, C. juncea and soybean was larger compared to cotton. Despite the fact that the adults did not discriminate among plants, in dual-choice test, the proportion of eggs layed and leaf consumption by P. cuyabana adults in soybean were significantly higher than in C. spectabilis. The larval distribution in the soil was at random in multiple-choice, without any trend of preference, but in dual-choice, when soybean was the control, larvae always preferred to feed on its roots. P. cuyabana adults had preference for more suitable hosts and that could stand their offspring survival. This behaviour can be usefully exploited in an integrated management program for this pest. (author)
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Lenita J.; Hoffmann-Campo, Clara B. [EMBRAPA Soja, Londrina, PR (Brazil). Centro Nacional de Pesquisa de Soja]. E-mail: lenita@cnpso.embrapa.br; Garcia, Maria A. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Zoologia; Amaral, Maria L.B. do [Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasilia, DF (Brazil)
2007-09-15
Laboratory and greenhouse experiments were carried out to study food and oviposition preference by Phyllophaga cuyabana (Moser) on different plant species as Cajanus cajan L. (pigeon pea), Crotalaria juncea L. (sun hemp), Crotalaria spectabilis Roth (showy crotalaria), Crotalaria ochroleuca G. Don (slenderleaf rattlebox), Glycine max [L.] Merrill (soybean), Gossypium hirsutum L. (cotton), Helianthus annuus L. (sunflower), Stizolobium aterrimum [Mucuna aterrima] Piper and Tracey (velvetbean) and Zea mays L. (mayze). In no-choice experiments, the number of eggs layed in sunflower, C. juncea and soybean was larger compared to cotton. Despite the fact that the adults did not discriminate among plants, in dual-choice test, the proportion of eggs layed and leaf consumption by P. cuyabana adults in soybean were significantly higher than in C. spectabilis. The larval distribution in the soil was at random in multiple-choice, without any trend of preference, but in dual-choice, when soybean was the control, larvae always preferred to feed on its roots. P. cuyabana adults had preference for more suitable hosts and that could stand their offspring survival. This behaviour can be usefully exploited in an integrated management program for this pest. (author)
DEFF Research Database (Denmark)
Rännbäck, Linda-Marie; Cotes, Belen; Anderson, Peter
2015-01-01
brunneum isolate KVL 04-57 and Beauveria bassiana isolate KVL 03-90. Furthermore, T. rapae oviposition behavior was assessed in the presence of these entomopathogenic fungi either as infected hosts or as infective propagules in the environment. Both fungi were pathogenic to D. radicum larvae and T. rapae...... adults, but with variable virulence. When host patches were inoculated with M. brunneum conidia in a no-choice situation, more eggs were laid by T. rapae in hosts of those patches compared to control and B. bassiana treated patches. Females that later succumbed to mycosis from either fungusi laid...... larvae. This was less pronounced for B. bassiana. Based on our results we propose that T. rapae can perceive and react towards IGP risk posed by M. brunneum but not B. bassiana to the foraging female herself and her offspring. Thus, M. brunneum has the potential to be used for biological control against...
Optimization of near and far patterns field in InxGa1-xN Lasers
International Nuclear Information System (INIS)
Martín, Juan A.; Mon, E.; Sánchez, M.
2008-01-01
The introduction on the market of lasers based on In x Ga 1-x N emitted at short wavelengths (λ = 430-450 nm), has enabled a considerable increase of the density of data storage on optical discs. However, despite the successes in the manufacture of these lasers are still far from being optimized. One of the difficulties present in these structures is the technological difficulty to grow In x Ga 1-x N cladding layers with high aluminum content (x>0.13) and wide enough to ensure the necessary optical confinement. This difficulty is due to the network constant difference between the Al x Ga 1-x N and the GaN and the presence of narrow cladding layers causes the undesirable high-order modes in [1] far field patterns. This paper analyzes the influence of the thickness of the layers that form the structure on the patterns of field near and far In x Ga 1-x N structures with multiple quantum wells in the active area. Structures are compared with staggered and parabolic variation of the refractive index. Found that with appropriate combinations of the thickness of this layer the detrimental effects that appear in from near and far field patterns can be eliminated without the need to grow very wide cladding layers, which represents an alternative solution to this technological problem [2]. [1] M. Onomura et al, IEEE J. Sel. Top. Quantum Electron. 5 (1999) 76. [2] J.A. Martín et al. Superlattices and Microstructures 43 (200 8) 575.
Analysis of fracture patterns and local stress field variations in fractured reservoirs
Deckert, Hagen; Drews, Michael; Fremgen, Dominik; Wellmann, J. Florian
2010-05-01
A meaningful qualitative evaluation of permeabilities in fractured reservoirs in geothermal or hydrocarbon industry requires the spatial description of the existing discontinuity pattern within the area of interest and an analysis how these fractures might behave under given stress fields. This combined information can then be used for better estimating preferred fluid pathway directions within the reservoir, which is of particular interest for defining potential drilling sites. A description of the spatial fracture pattern mainly includes the orientation of rock discontinuities, spacing relationships between single fractures and their lateral extent. We have examined and quantified fracture patterns in several outcrops of granite at the Costa Brava, Spain, and in the Black Forest, Germany, for describing reservoir characteristics. For our analysis of fracture patterns we have used photogrammetric methods to create high-resolution georeferenced digital 3D images of outcrop walls. The advantage of this approach, compared to conventional methods for fracture analysis, is that it provides a better 3D description of the fracture geometry as the entity of position, extent and orientation of single fractures with respect to their surrounding neighbors is conserved. Hence for instance, the method allows generating fracture density maps, which can be used for a better description of the spatial distribution of discontinuities in a given outcrop. Using photogrammetric techniques also has the advantage to acquire very large data sets providing statistically sound results. To assess whether the recorded discontinuities might act as fluid pathways information on the stress field is needed. A 3D model of the regional tectonic structure was created and the geometry of the faults was put into a mechanical 3D Boundary Element (BE) Model. The model takes into account the elastic material properties of the geological units and the orientation of single fault segments. The
Sianturi, Riswan; Jetten, V. G.; Sartohadi, Junun
2018-04-01
Information on the vulnerability to flooding is vital to understand the potential damages from flood events. A method to determine the vulnerability to flooding in irrigated rice fields using the Enhanced Vegetation Index (EVI) was proposed in this study. In doing so, the time-series EVI derived from time-series 8 day 500 m spatial resolution MODIS imageries (MOD09A1) was used to generate cropping patterns in irrigated rice fields in West Java. Cropping patterns were derived from the spatial distribution and phenology metrics so that it is possible to show the variation of vulnerability in space and time. Vulnerability curves and cropping patterns were used to determine the vulnerability to flooding in irrigated rice fields. Cropping patterns capture the shift in the vulnerability, which may lead to either an increase or decrease of the degree of damage in rice fields of origin and other rice fields. The comparison of rice field areas between MOD09A1 and ALOS PALSAR and MOD09A1 and Agricultural Statistics showed consistent results with R2 = 0.81 and R2 = 0.93, respectively. The estimated and observed DOYs showed RMSEs = 9.21, 9.29, and 9.69 days for the Start of Season (SOS), heading stage, and End of Season (EOS), respectively. Using the method, one can estimate the relative damage provided available information on the flood depth and velocity. The results of the study may support the efforts to reduce the potential damages from flooding in irrigated rice fields.
A simple field method to identify foot strike pattern during running.
Giandolini, Marlène; Poupard, Thibaut; Gimenez, Philippe; Horvais, Nicolas; Millet, Guillaume Y; Morin, Jean-Benoît; Samozino, Pierre
2014-05-07
Identifying foot strike patterns in running is an important issue for sport clinicians, coaches and footwear industrials. Current methods allow the monitoring of either many steps in laboratory conditions or only a few steps in the field. Because measuring running biomechanics during actual practice is critical, our purpose is to validate a method aiming at identifying foot strike patterns during continuous field measurements. Based on heel and metatarsal accelerations, this method requires two uniaxial accelerometers. The time between heel and metatarsal acceleration peaks (THM) was compared to the foot strike angle in the sagittal plane (αfoot) obtained by 2D video analysis for various conditions of speed, slope, footwear, foot strike and state of fatigue. Acceleration and kinematic measurements were performed at 1000Hz and 120Hz, respectively, during 2-min treadmill running bouts. Significant correlations were observed between THM and αfoot for 14 out of 15 conditions. The overall correlation coefficient was r=0.916 (Pstrike except for extreme forefoot strike during which the heel rarely or never strikes the ground, and for different footwears and states of fatigue. We proposed a classification based on THM: FFS<-5.49ms
The magnetic source imaging of pattern reversal stimuli of various visual fields
International Nuclear Information System (INIS)
Zhang Shuqian; Ye Yufang; Sun Jilin; Wu Jie; Jia Xiuchuan; Li Sumin; Wu Jing; Zhao Huadong; Liu Lianxiang; Wu Yujin
2006-01-01
Objective: To have acknowledgement of characteristics of normal volunteers visual evoked fields about full field, vertical half field and quadrant field and their dipole location by magnetoencephalography. Methods: The visual evoked fields of full field, vertical half field and quadrant field were detected with 13 subjects. The latency, dipole strength and dipoles' location on x, y and z axis were analyzed. The exact locations of the dipoles were detected by overlapping on MR images. Results: The isocontour map of M100 of full field stimulation demonstrated two separate sources. The two M100 dipoles had same peak latency and different strength. And for vertical half field and quadrant field stimulation, evoked magnetic fields of M100 distributed contralateral to the stimulated side. The M100 dipoles on the z-axis to the lower quadrant field stimulation were located significantly higher than those to the upper quadrant field stimulation. The Z value median of left upper quadrant was 49.6 (35.1-72.8) mm. The Z value median of left lower quadrant was 53.5 (44.8-76.3) mm. The different of two left quadrant medians, 3.9 mm, was significant (P<0.05). The Z value median of right upper quadrant was 40.0 (34.8-44.6) mm. The Z value median of right lower quadrant was 53.8 (40.6-61.3) mm. The different of two right quadrant medians, 13.8 mm, was also significant (P<0.05). Although each of the visual evoked fields waveforms and dipole locations demonstrated large intra- and inter-individual variations, the dipole of M100 was mainly located at area Brodmann 17, which includes superior lingual gyrus, posterior cuneus-lingual gyrus and inferior cuneus gyms. Conclusion: The M100 of visual evoked fields of pattern reversal stimulation is mainly generated by the neurons of striate cortex of contralateral to the stimulated side, which is at the lateral bottom of the calcarine fissure. (authors)
[Runoff Pollution Experiments of Paddy Fields Under Different Irrigation Patterns].
Zhou, Jing-wen; Su, Bao-lin; Huang, Ning-bo; Guan, Yu-tang; Zhao, Kun
2016-03-15
To study runoff and non-point source pollution of paddy fields and to provide a scientific basis for agricultural water management of paddy fields, paddy plots in the Jintan City and the Liyang City were chosen for experiments on non-point source pollution, and flood irrigation and intermittent irrigation patterns were adopted in this research. The surface water level and rainfall were observed during the growing season of paddies, and the runoff amount from paddy plots and loads of total nitrogen (TN) and total phosphorus (TP) were calculated by different methods. The results showed that only five rain events of totally 27 rainfalls and one artificially drainage formed non-point source pollution from flood irrigated paddy plot, which resulted in a TN export coefficient of 49.4 kg · hm⁻² and a TP export coefficient of 1.0 kg · hm⁻². No any runoff event occurred from the paddy plot with intermittent irrigation even in the case of maximum rainfall of 95.1 mm. Runoff from paddy fields was affected by water demands of paddies and irrigation or drainage management, which was directly correlated to surface water level, rainfall amount and the lowest ridge height of outlets. Compared with the flood irrigation, intermittent irrigation could significantly reduce non-point source pollution caused by rainfall or artificial drainage.
Fertility patterns of college graduates by field of study, US women born 1960-79.
Michelmore, Katherine; Musick, Kelly
2014-01-01
Building on recent European studies, we used the Survey of Income and Program Participation to provide the first analysis of fertility differences between groups of US college graduates by their undergraduate field of study. We used multilevel event-history models to investigate possible institutional and selection mechanisms linking field of study to delayed fertility and childlessness. The results are consistent with those found for Europe in showing an overall difference of 10 percentage points between levels of childlessness across fields, with the lowest levels occurring for women in health and education, intermediate levels for women in science and technology, and the highest levels for women in arts and social sciences. The mediating roles of the following field characteristics were assessed: motherhood employment penalties; percentage of men; family attitudes; and marriage patterns. Childlessness was higher among women in fields with a moderate representation of men, less traditional family attitudes, and late age at first marriage.
Raghavan, Ramanujan T; Joshua, Mati
2017-10-01
We investigated the composition of preparatory activity of frontal eye field (FEF) neurons in monkeys performing a pursuit target selection task. In response to the orthogonal motion of a large and a small reward target, monkeys initiated pursuit biased toward the direction of large reward target motion. FEF neurons exhibited robust preparatory activity preceding movement initiation in this task. Preparatory activity consisted of two components, ramping activity that was constant across target selection conditions, and a flat offset in firing rates that signaled the target selection condition. Ramping activity accounted for 50% of the variance in the preparatory activity and was linked most strongly, on a trial-by-trial basis, to pursuit eye movement latency rather than to its direction or gain. The offset in firing rates that discriminated target selection conditions accounted for 25% of the variance in the preparatory activity and was commensurate with a winner-take-all representation, signaling the direction of large reward target motion rather than a representation that matched the parameters of the upcoming movement. These offer new insights into the role that the frontal eye fields play in target selection and pursuit control. They show that preparatory activity in the FEF signals more strongly when to move rather than where or how to move and suggest that structures outside the FEF augment its contributions to the target selection process. NEW & NOTEWORTHY We used the smooth eye movement pursuit system to link between patterns of preparatory activity in the frontal eye fields and movement during a target selection task. The dominant pattern was a ramping signal that did not discriminate between selection conditions and was linked, on trial-by-trial basis, to movement latency. A weaker pattern was composed of a constant signal that discriminated between selection conditions but was only weakly linked to the movement parameters. Copyright © 2017 the American
Auroral arc classification scheme based on the observed arc-associated electric field pattern
International Nuclear Information System (INIS)
Marklund, G.
1983-06-01
Radar and rocket electric field observations of auroral arcs have earlier been used to identify essentially four different arc types, namely anticorrelation and correlation arcs (with, respectively, decreased and increased arc-assocaited field) and asymmetric and reversal arcs. In this paper rocket double probe and supplementary observations from the literature, obtained under various geophysical conditions, are used to organize the different arc types on a physical rather than morphological basis. This classification is based on the relative influence on the arc electric field pattern from the two current continuity mechanisms, polarisation electric fields and Birkeland currents. In this context the tangential electric field plays an essential role and it is thus important that it can be obtained with both high accuracy and resolution. In situ observations by sounding rockets are shown to be better suited for this specific task than monostatic radar observations. Depending on the dominating mechanism, estimated quantitatively for a number of arc-crossings, the different arc types have been grouped into the following main categories: Polarisation arcs, Birkeland current arcs and combination arcs. Finally the high altitude potential distributions corresponding to some of the different arc types are presented. (author)
Receptive fields of locust brain neurons are matched to polarization patterns of the sky.
Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram
2014-09-22
Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation. Copyright © 2014 Elsevier Ltd. All rights reserved.
Protopapa, M L; De Tomasi, F; Di Giulio, M; Perrone, M R; Scaglione, S
2002-01-01
The standing-wave electric field pattern that forms inside an optical coating as a consequence of laser irradiation is one of the factors influencing the coating laser-induced damage threshold. The influence of the standing-wave electric field profile on the damage resistance to ultraviolet radiation of hafnium dioxide (HfO sub 2) thin films was investigated in this work. To this end, HfO sub 2 thin films of different thicknesses deposited by the electron beam evaporation technique at the same deposition conditions were analyzed. Laser damage thresholds of the samples were measured at 308 nm (XeCl laser) by the photoacoustic beam deflection technique and microscopic inspections. The dependence of the laser damage threshold on the standing-wave electric field pattern was analyzed.
Mango resistance to fruit flies. II - resistance of the alfa cultivar
Energy Technology Data Exchange (ETDEWEB)
Rossetto, C.J.; Bortoletto, N., E-mail: rossetto@iac.sp.gov.b [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Votuporanga, SP (Brazil). Polo Regional do Noroeste Paulista; Walder, J.M.M.; Mastrangelo, T. de A., E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Carvalho, C.R.L.; Castro, J.V. de, E-mail: climonta@iac.sp.gov.b, E-mail: josalba@iac.sp.gov.b [Instituto Agronomico de Campinas, SP (Brazil); Pinto, A.C. de Q. [EMBRAPA, Brasilia, DF (Brazil); Cortelazzo, A.L., E-mail: angelo@unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia
2006-07-01
The percentage of infested mango fruits of five selected mango varieties was evaluated during three years under field conditions. Three varieties with field resistance to fruit flies had less then 10% of fruits infested. Tommy Atkins, the susceptible commercial check, had 42,9% and the susceptible check had 98.9 % of infested fruits. The three field resistant varieties plus the susceptible commercial check, Tommy Atkins, were further tested in laboratory, under caged conditions, with artificial infestation of Anastrepha obliqua. The attempts of oviposition and the number of pupae developed from each fruit were evaluated. Under caged conditions, the cultivar Alfa maintained its field resistance and Espada Stahl and IAC 111 lost the field resistance and were as susceptible as Tommy Atkins. The attempts of oviposition were positively and highly correlated with the number of pupae developed in the fruits. Non preference for oviposition was confirmed as the main mechanism of resistance of mango fruits to fruit flies. In the absence of a more susceptible variety (no choice test) the cultivar Alfa has kept the resistance (author)
Mango resistance to fruit flies. II - resistance of the alfa cultivar
International Nuclear Information System (INIS)
Rossetto, C.J.; Bortoletto, N.; Carvalho, C.R.L.; Castro, J.V. de; Pinto, A.C. de Q.; Cortelazzo, A.L.
2006-01-01
The percentage of infested mango fruits of five selected mango varieties was evaluated during three years under field conditions. Three varieties with field resistance to fruit flies had less then 10% of fruits infested. Tommy Atkins, the susceptible commercial check, had 42,9% and the susceptible check had 98.9 % of infested fruits. The three field resistant varieties plus the susceptible commercial check, Tommy Atkins, were further tested in laboratory, under caged conditions, with artificial infestation of Anastrepha obliqua. The attempts of oviposition and the number of pupae developed from each fruit were evaluated. Under caged conditions, the cultivar Alfa maintained its field resistance and Espada Stahl and IAC 111 lost the field resistance and were as susceptible as Tommy Atkins. The attempts of oviposition were positively and highly correlated with the number of pupae developed in the fruits. Non preference for oviposition was confirmed as the main mechanism of resistance of mango fruits to fruit flies. In the absence of a more susceptible variety (no choice test) the cultivar Alfa has kept the resistance (author)
International Nuclear Information System (INIS)
Treushnikov, E.N.
2000-01-01
The problem of the theoretical description of X-ray diffraction from ideal mosaic crystals under the effect of various external fields has been formulated. Electric, magnetic, electromagnetic, and acoustic perturbations are considered. The atomic displacements in crystals under the effect of external fields and the types of the corresponding diffraction patterns are analyzed for various types of perturbations. The crystal classes are determined in which atomic displacements can be recorded experimentally. Diffraction patterns formed under the effect of various external factors are considered on the basis of the derived dependence of the structure factor on the characteristics of an applied force field
Temporal Patterns of Glyphosate Leaching at a Loamy Agricultural Field in Denmark
DEFF Research Database (Denmark)
Nørgaard, Trine; Møldrup, Per; Olsen, Preben
2013-01-01
applications in combination with the effect of precipitation events, drain water runoff, soil water content at 25 cm soil depth, management, and particle leaching patterns, and compares this with monitored field-scale glyphosate and AMPA leaching to a tile drainage system. Preliminary findings indicate...... that there is an accumulation of glyphosate and AMPA in the soil after the successive applications of glyphosate, as the level of the peaking concentrations right after applications increases. Furthermore, large precipitation events with subsequent high drain water runoff together with management, especially plowing...
First proteome of the egg perivitelline fluid of a freshwater gastropod with aerial oviposition
Sun, Jin
2012-08-03
Pomacea canaliculata is a freshwater snail that deposits eggs on solid substrates above the water surface. Previous studies have emphasized the nutritional and protective functions of the three most abundant perivitelline fluid (PVF) protein complexes (ovorubin, PV2, and PV3) during its embryonic development, but little is known about the structure and function of other less abundant proteins. Using 2-DE, SDS-PAGE, MALDI TOF/TOF, and LC-MS/MS, we identified 59 proteins from the PVF of P. canaliculata, among which 19 are novel. KEGG analysis showed that the functions of the majority of these proteins are "unknown" (n = 34), "environmental information processing" (10), 9 of which are related to innate immunity, and "metabolism" (7). Suppressive subtractive hybridization revealed 21 PVF genes to be specific to the albumen gland, indicating this organ is the origin of many of the PVF proteins. Further, the 3 ovorubin subunits were identified with 30.2-35.0% identity among them, indicating their common origin but ancient duplications. Characterization of the PVF proteome has opened the gate for further studies aiming to understand the evolution of the novel proteins and their contribution to the switch to aerial oviposition. © 2012 American Chemical Society.
Fertility patterns of college graduates by field of study, U.S. women born 1960--79
Michelmore, Katherine; Musick, Kelly
2013-01-01
Building on recent European studies, we used the Survey of Income and Program Participation to provide the first analysis of fertility differences between groups of U.S. college graduates by their undergraduate field of study. We used multilevel event-history models to investigate possible institutional and selection mechanisms linking field of study to delayed fertility and childlessness. The results are consistent with those found for Europe in showing an overall difference of 10 percentage points between levels of childlessness across fields, with the lowest levels occurring for women in health and education, intermediate levels for women in science and technology, and the highest levels for women in arts and social sciences. The mediating roles of the following field characteristics were assessed: motherhood employment penalties; percentage of men; family attitudes; and marriage patterns. Childlessness was higher among women in fields with a moderate representation of men, less traditional family attitudes, and late age at first marriage. PMID:24266547
International Nuclear Information System (INIS)
Kurra, Narendra; Bhadram, Venkata Srinu; Narayana, Chandrabhas; Kulkarni, G U
2012-01-01
We describe a transfer-free method for the fabrication of nanocrystalline graphene (nc-graphene) on SiO 2 substrates directly from patterned carbonaceous deposits. The deposits were produced from the residual hydrocarbons present in the vacuum chamber without any external source by using an electron beam induced carbonaceous deposition (EBICD) process. Thermal treatment under vacuum conditions in the presence of Ni catalyst transformed the EBIC deposit into nc-graphene patterns, confirmed using Raman and TEM analysis. The nc-graphene patterns have been employed as an active p-type channel material in a field effect transistor (FET) which showed a hole mobility of ∼90 cm 2 V −1 s −1 . The nc-graphene also proved to be suitable material for IR detection. (paper)
Energy Technology Data Exchange (ETDEWEB)
Yépez, L.D.; Carrillo, J.L. [Instituto de Física de la Universidad Autónoma de Puebla, Ciudad Universitaria, Edif. 110 A, Puebla 72570 (Mexico); Donado, F.; Sausedo-Solorio, J.M.; Miranda-Romagnoli, P. [Instituto de Ciencias Básicas e Ingeniería Universidad Autónoma del Estado de Hidalgo, Pachuca 42090, Pachuca (Mexico)
2016-06-15
The dynamical pattern formation of clusters of magnetic particles in a low-concentration magnetorheological fluid, under the influence of a superposition of two perpendicular sinusoidal fields, is studied experimentally. By varying the frequency and phase shift of the perpendicular fields, this configuration enables us to experimentally analyze a wide range of field configurations, including the case of a pure rotating field and the case of an oscillating unidirectional field. The fields are applied parallel to the horizontal plane where the fluid lies or in the vertical plane. For fields applied in the horizontal plane, we observed that, when the ratio of the frequencies increases, the average cluster size exhibits a kind of periodic resonances. When the phase shift between the fields is varied, the average chain length reaches maximal values for the cases of the rotating field and the unidirectional case. We analyze and discuss these results in terms of a weighted average of the time-dependent Mason number. In the case of a rotating field on the vertical plane, we also observe that the competition between the magnetic and the viscous forces determines the average cluster size. We show that this configuration generates a series of physically meaningful self-organization of clusters and transport phenomena. - Highlights: • A weighted average of the time-dependent Mason number is proposed. • The self-propelling clusters appear when a vertical rotating magnetic field is applied. • The largest average chain lengths are reached when frequencies are multiples one another. • Rotating and unidirectional alternating fields produce the largest average chain length values.
International Nuclear Information System (INIS)
Yépez, L.D.; Carrillo, J.L.; Donado, F.; Sausedo-Solorio, J.M.; Miranda-Romagnoli, P.
2016-01-01
The dynamical pattern formation of clusters of magnetic particles in a low-concentration magnetorheological fluid, under the influence of a superposition of two perpendicular sinusoidal fields, is studied experimentally. By varying the frequency and phase shift of the perpendicular fields, this configuration enables us to experimentally analyze a wide range of field configurations, including the case of a pure rotating field and the case of an oscillating unidirectional field. The fields are applied parallel to the horizontal plane where the fluid lies or in the vertical plane. For fields applied in the horizontal plane, we observed that, when the ratio of the frequencies increases, the average cluster size exhibits a kind of periodic resonances. When the phase shift between the fields is varied, the average chain length reaches maximal values for the cases of the rotating field and the unidirectional case. We analyze and discuss these results in terms of a weighted average of the time-dependent Mason number. In the case of a rotating field on the vertical plane, we also observe that the competition between the magnetic and the viscous forces determines the average cluster size. We show that this configuration generates a series of physically meaningful self-organization of clusters and transport phenomena. - Highlights: • A weighted average of the time-dependent Mason number is proposed. • The self-propelling clusters appear when a vertical rotating magnetic field is applied. • The largest average chain lengths are reached when frequencies are multiples one another. • Rotating and unidirectional alternating fields produce the largest average chain length values.
Directory of Open Access Journals (Sweden)
Francisco R Badenes-Perez
Full Text Available Glucosinolates are plant secondary metabolites used in plant defense. For insects specialized on Brassicaceae, such as the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae, glucosinolates act as "fingerprints" that are essential in host plant recognition. Some plants in the genus Barbarea (Brassicaceae contain, besides glucosinolates, saponins that act as feeding deterrents for P. xylostella larvae, preventing their survival on the plant. Two-choice oviposition tests were conducted to study the preference of P. xylostella among Barbarea leaves of different size within the same plant. P. xylostella laid more eggs per leaf area on younger leaves compared to older ones. Higher concentrations of glucosinolates and saponins were found in younger leaves than in older ones. In 4-week-old plants, saponins were present in true leaves, while cotyledons contained little or no saponins. When analyzing the whole foliage of the plant, the content of glucosinolates and saponins also varied significantly in comparisons among plants that were 4, 8, and 12 weeks old. In Barbarea plants and leaves of different ages, there was a positive correlation between glucosinolate and saponin levels. This research shows that, in Barbarea plants, ontogenetical changes in glucosinolate and saponin content affect both attraction and resistance to P. xylostella. Co-occurrence of a high content of glucosinolates and saponins in the Barbarea leaves that are most valuable for the plant, but are also the most attractive to P. xylostella, provides protection against this specialist herbivore, which oviposition behavior on Barbarea seems to be an evolutionary mistake.
Badenes-Perez, Francisco R.; Gershenzon, Jonathan; Heckel, David G.
2014-01-01
Glucosinolates are plant secondary metabolites used in plant defense. For insects specialized on Brassicaceae, such as the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), glucosinolates act as “fingerprints” that are essential in host plant recognition. Some plants in the genus Barbarea (Brassicaceae) contain, besides glucosinolates, saponins that act as feeding deterrents for P. xylostella larvae, preventing their survival on the plant. Two-choice oviposition tests were conducted to study the preference of P. xylostella among Barbarea leaves of different size within the same plant. P. xylostella laid more eggs per leaf area on younger leaves compared to older ones. Higher concentrations of glucosinolates and saponins were found in younger leaves than in older ones. In 4-week-old plants, saponins were present in true leaves, while cotyledons contained little or no saponins. When analyzing the whole foliage of the plant, the content of glucosinolates and saponins also varied significantly in comparisons among plants that were 4, 8, and 12 weeks old. In Barbarea plants and leaves of different ages, there was a positive correlation between glucosinolate and saponin levels. This research shows that, in Barbarea plants, ontogenetical changes in glucosinolate and saponin content affect both attraction and resistance to P. xylostella. Co-occurrence of a high content of glucosinolates and saponins in the Barbarea leaves that are most valuable for the plant, but are also the most attractive to P. xylostella, provides protection against this specialist herbivore, which oviposition behavior on Barbarea seems to be an evolutionary mistake. PMID:24752069
Directory of Open Access Journals (Sweden)
Edy Syahputra .
2011-11-01
Full Text Available Preparation of Barringtonia asiatica: insecticidal activity against Crocidolomia pavonana on laboratory and effectiveness on field. The objectives of this study were to evaluate the insecticidal and anti-oviposition activity of ethanol seed extract of Barringtonia asiatica against Crocidolomia pavonana in the laboratory, and to determine the effectiveness of a simple preparation of B. asiatica seeds in supressing oviposition and population of C. pavonana in the field. The mortality bioassays were conducted by a leaf-feeding method. Anti-oviposition activity was assessed by a choice-test in the nursery. The results showed that the ethanol seed extract of B. asiatica possessed strong insecticidal activity against C. pavonana larvae with LC50 of 0.14%. The extract at concentrations of 0.14-1.00% reduced oviposition by C. pavonana female as much as 65.7-95.6%. B. asiatica seeds ground in water for 5 seconds and then immersed for 1 hour at a concentration of 50 g l-1 yielded a simple preparation which was active against C. pavoana larvae. Such simple preparation at a concentration of 75 g l-1 sprayed on cabbage crop effectively suppressed population of C. pavonana larvae in the field.
Cloonan, Kevin R.; Andreadis, Stefanos S.; Chen, Haibin; Jenkins, Nina E.; Baker, Thomas C.
2016-01-01
We previously showed that the females of the mushroom sciarid, Lycoriella ingenua (Dufour, 1839) (Diptera: Sciaridae), one of the most severe pests of the cultivated white button mushroom, Agaricus bisporus (J.E. Lange) Emil J. Imbach (Agaricales: Agaricaceae), are attracted to the mushroom compost that mushrooms are grown on and not to the mushrooms themselves. We also showed that females are attracted to the parasitic green mold, Trichoderma aggressivum. In an attempt to identify what is in the mushroom compost that attracts female L. ingenua, we isolated several species of fungi from adult males and females, third instar larvae, and mushroom compost itself. We then analyzed the attraction of females to these substrates using a static-flow two choice olfactometer, as well as their oviposition tendencies in another type of assay under choice and no-choice conditions. We also assessed the survival of larvae to adulthood when first instar larvae were placed on each of the isolated fungal species. We found that female flies were attracted most to the mycoparasitic green mold, T. aggressivum, to Penicilium citrinum isolated from adult female bodies, and to Scatylidium thermophilium isolated from the mushroom compost. Gravid female flies laid the most eggs on T. aggressivum, Aspergillus flavus isolated from third instar larval frass, Aspergillus fumigatus isolated from adult male bodies, and on P. citrinum. This egg-laying trend remained consistent under no-choice conditions as females aged. First instar larvae developed to adulthood only on S. thermophilium and Chaetomium sp. isolated from mushroom compost, and on P. citrinum. Our results indicate that the volatiles from a suite of different fungal species act in tandem in the natural setting of mushroom compost, with some first attracting gravid female flies and then others causing them to oviposit. The ecological context of these findings is important for creating an optimal strategy for using possible
Energy Technology Data Exchange (ETDEWEB)
Hong, Sung Ju; Park, Min; Kang, Hojin; Park, Yung Woo, E-mail: ywpark@snu.ac.kr [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Lee, Minwoo; Jeong, Dae Hong [Department of Chemistry Education, Seoul National University, Seoul 151-742 (Korea, Republic of)
2016-08-15
We report the fabrication of a patterned polymer electrolyte for a two-dimensional (2D) semiconductor, few-layer tungsten diselenide (WSe{sub 2}) field-effect transistor (FET). We expose an electron-beam in a desirable region to form the patterned structure. The WSe{sub 2} FET acts as a p-type semiconductor in both bare and polymer-covered devices. We observe a highly efficient gating effect in the polymer-patterned device with independent gate control. The patterned polymer gate operates successfully in a molybdenum disulfide (MoS{sub 2}) FET, indicating the potential for general applications to 2D semiconductors. The results of this study can contribute to large-scale integration and better flexibility in transition metal dichalcogenide (TMD)-based electronics.
Vignoli, Leonardo; Bologna, Marco A.; Luiselli, Luca
2007-03-01
We studied community structure and seasonal activity patterns in a system of four ponds with seasonally-variable hydrology at a Mediterranean area in central Italy. We used a set of field methods to assess species presence and relative frequency of observation. The network of ponds was inhabited by six species of amphibians, two salamanders and four frogs. The breeding phenology of the six species did not vary remarkably among ponds, but there were significant differences among species in use of ponds. Factorial analysis of pond similarity drawn from percentage composition of the amphibian fauna, revealed that each of the four ponds was treatable as independent units, with no influence of relative inter-pond distance. PCA analysis allowed us to spatially arrange the amphibian species into three main groups: two were monospecific groups (i.e., Triturus vulgaris and Bufo bufo) and the third consisted of those species that selected not only the largest-deepest ponds, but also the ephemeral ones (i.e., Triturus carnifex, Hyla intermedia, the green frogs and Rana dalmatina). Our results suggest that the inter-pond differences in riparian vegetation, water depth, aquatic vegetation structure/abundance, and soil composition may produce differences among pond ecological characteristics (i.e., water turbidity and temperature, shelter availability, abundance of oviposition micro-sites), which may in turn influence different patterns of use by amphibians. To our knowledge, this is the first study emphasizing the potential role of heterochrony in the maintenance of a high species richness in Mediterranean amphibian communities. Preservation of freshwater vertebrate biodiversity requires management and protection not only of the main ponds and water bodies but also the temporary and ephemeral shallow ponds.
López-Ley, Jorge Ulises; Toledo, Jorge; Malo, Edi A; Gomez, Jaime; Santiesteban, Antonio; Rojas, Julio C
2016-02-01
In this study, we investigated the influence of cultivar type, fruit ripeness, and damage by conspecific larvae on the attraction of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) to and oviposition on carambola fruit (Averroha carambola L.). The attraction of both sexes of A. obliqua to fruit of different quality was evaluated through cage experiments in the field, and the oviposition preferences of mated females were examined in laboratory tests. Both sexes, mated or virgin, were more attracted to the "Maha" fruit than to the "Golden Star" fruit, and the females oviposited more frequently on the Maha cultivar than the Golden Star cultivar. Both sexes were more attracted to ripe and half-ripe Maha fruits than to mature green fruit, and although females did not show a preference for ovipositing on half-ripe or ripe fruits, they did not oviposit on mature green fruits. Males did not show a preference for the volatiles from uninfested, artificially damaged, or infested Maha fruits, but females were more attracted to uninfested fruits than to artificially damaged and infested Maha fruits. Furthermore, females preferred to oviposit on uninfested fruits compared with artificially damaged fruit, and they did not oviposit on infested fruits. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Flow patterns of GaInSn liquid on inclined stainless steel plate under a range of magnetic field
Energy Technology Data Exchange (ETDEWEB)
Yang, Juan-Cheng, E-mail: yangjc@xjtu.edu.cn [State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi’an Jiaotong University, Xi’an, Shanxi 710049 (China); Qi, Tian-Yu [School of Engineering Sciences, University of Chinese Academy and Sciences, Beijing 100049 (China); Ni, Ming-Jiu, E-mail: mjni@ucas.ac.cn [School of Engineering Sciences, University of Chinese Academy and Sciences, Beijing 100049 (China); Wang, Zeng-Hui [School of Engineering Sciences, University of Chinese Academy and Sciences, Beijing 100049 (China)
2016-11-01
Highlights: • The liquid GaInSn metal flow loop was built to study some fusion related liquid metal MHD phenomenon. • The flow patterns of GaInSn free surface flow with the change of Re number and Ha number were got by lot of experiments. • Some detailed descriptions of these flow patterns were also made, and a solid conclusion which agreed with some previous studies was got. - Abstract: In the present paper, some preliminary experimental studies have been conducted to show the flow pattern of liquid metal flow using visualization method. For the convenience of experiments in lab, Ga{sup 67}In{sup 20.5}Sn{sup 12.5} in liquid state at room temperature is used. A test section made by stainless steel is inserted in a traverse magnetic field with strength (B{sub 0}) varies from 0 to 1.28 T. The inclined angle of stainless steel plate in test section is about 9°. Visualization results obtained by high-speed camera (Phantom M/LC 310) shown that GaInSn liquid flow on inclined stainless steel plate behaved unstable liquid column flow pattern in the low flow rate, while behaved large area spreading flow pattern with small waves on the free surface in the large flow rate. However, in the magnetic field, under the action of electromagnetic force, the flow patterns of GaInSn liquid have some significant changes on the spreading width and surface structure of free surface. Some detailed analyses on these changes have been also showed in the present paper. Plans for future work are also presented.
Vaidya, Manushka V; Collins, Christopher M; Sodickson, Daniel K; Brown, Ryan; Wiggins, Graham C; Lattanzi, Riccardo
2016-02-01
In high field MRI, the spatial distribution of the radiofrequency magnetic ( B 1 ) field is usually affected by the presence of the sample. For hardware design and to aid interpretation of experimental results, it is important both to anticipate and to accurately simulate the behavior of these fields. Fields generated by a radiofrequency surface coil were simulated using dyadic Green's functions, or experimentally measured over a range of frequencies inside an object whose electrical properties were varied to illustrate a variety of transmit [Formula: see text] and receive [Formula: see text] field patterns. In this work, we examine how changes in polarization of the field and interference of propagating waves in an object can affect the B 1 spatial distribution. Results are explained conceptually using Maxwell's equations and intuitive illustrations. We demonstrate that the electrical conductivity alters the spatial distribution of distinct polarized components of the field, causing "twisted" transmit and receive field patterns, and asymmetries between [Formula: see text] and [Formula: see text]. Additionally, interference patterns due to wavelength effects are observed at high field in samples with high relative permittivity and near-zero conductivity, but are not present in lossy samples due to the attenuation of propagating EM fields. This work provides a conceptual framework for understanding B 1 spatial distributions for surface coils and can provide guidance for RF engineers.
Saleeb, A. F.; Prabhu, M.; Arnold, S. M. (Technical Monitor)
2002-01-01
Recently, a conceptually simple approach, based on the notion of defect energy in material space has been developed and extensively studied (from the theoretical and computational standpoints). The present study focuses on its evaluation from the viewpoint of damage localization capabilities in case of two-dimensional plates; i.e., spatial pattern recognition on surfaces. To this end, two different experimental modal test results are utilized; i.e., (1) conventional modal testing using (white noise) excitation and accelerometer-type sensors and (2) pattern recognition using Electronic speckle pattern interferometry (ESPI), a full field method capable of analyzing the mechanical vibration of complex structures. Unlike the conventional modal testing technique (using contacting accelerometers), these emerging ESPI technologies operate in a non-contacting mode, can be used even under hazardous conditions with minimal or no presence of noise and can simultaneously provide measurements for both translations and rotations. Results obtained have clearly demonstrated the robustness and versatility of the global NDE scheme developed. The vectorial character of the indices used, which enabled the extraction of distinct patterns for localizing damages proved very useful. In the context of the targeted pattern recognition paradigm, two algorithms were developed for the interrogation of test measurements; i.e., intensity contour maps for the damaged index, and the associated defect energy vector field plots.
Directory of Open Access Journals (Sweden)
L. Cafarella
2001-06-01
Full Text Available A statistical analysis of the polarization pattern of low-frequency geomagnetic field fluctuations (0.7-7.4 mHz covering the entire 24-h interval was performed at the Antarctic station Terra Nova Bay (80.0°S geomagnetic latitude throughout 1997 and 1998. The results show that the polarization pattern exhibits a frequency dependence, as can be expected from the frequency dependence of the latitude where the coupling between the magnetospheric compressional mode and the field line resonance takes place. The polarization analysis of single pulsation events shows that wave packets with different polarization sense, depending on frequency, can be simultaneously observed.
Research on cutoff wavelength of dominant mode and field patterns in trapezoidal microshield lines
SUN, Hai; WU, Yujiang
2012-01-01
The influence of the position of the metallic signal strip on the cutoff characteristic of the dominant mode and the field patterns in 3 types of trapezoidal microshield lines are calculated by the edge-based finite element method. These trapezoidal microshield lines include trapezoidal microshield lines with a single signal line, dual signal lines, and 3 signal lines. The cutoff wavelength of the dominant mode can be adjusted by changing the dimensions of metallic signal strips as w...
Study of high speed complex number algorithms. [for determining antenna for field radiation patterns
Heisler, R.
1981-01-01
A method of evaluating the radiation integral on the curved surface of a reflecting antenna is presented. A three dimensional Fourier transform approach is used to generate a two dimensional radiation cross-section along a planer cut at any angle phi through the far field pattern. Salient to the method is an algorithm for evaluating a subset of the total three dimensional discrete Fourier transform results. The subset elements are selectively evaluated to yield data along a geometric plane of constant. The algorithm is extremely efficient so that computation of the induced surface currents via the physical optics approximation dominates the computer time required to compute a radiation pattern. Application to paraboloid reflectors with off-focus feeds in presented, but the method is easily extended to offset antenna systems and reflectors of arbitrary shapes. Numerical results were computed for both gain and phase and are compared with other published work.
Chen, Ming-liang; Wang, Gang-yi; Chen, Min; Zhou, Hai-jian; Shao, Zhu-jun; Zhang, Xi; Wu, Fan
2010-07-01
To investigate the genotypic characteristics and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns in 16 air-conditioner cooling towers in six different public sites of Shanghai. From May to October, continuous sampling was operated once per month in 2007. Legionella strains isolated from the 16 cooling towers were confirmed by serological and latex agglutination. PFGE was applied for the fingerprinting of the isolates, while the cluster results of PFGE were analyzed by BioNumerics software. 131 strains of Legionella were isolated, including L. pneumophila, L. bozemanae, L. micdadei and L. anisa. 52 distinguishable PFGE patterns were differentiated among the 16 cooling towers, with 37 patterns were owned by just one cooling tower, which was not shared with other cooling towers, while 15 patterns were shared by more than 2 cooling towers. All the cooling towers had ≥ 2 PFGE patterns, while in 13 cooling towers the same PFGE patterns were recovered during the six months. From June to October of 2007, 18 strains of Legionella belonging to the PFGE pattern of LPAs.SH0078 were isolated continuously from 6 cooling towers. This study demonstrated great genotypic diversity and complexity of Legionella in cooling towers. Persistence of the PFGE patterns was observed in 81.25% of the cooling towers. The PFGE pattern of LPAs. SH0078 was distributed widely, suggesting it might be the dominate strain in Shanghai.
Method to mosaic gratings that relies on analysis of far-field intensity patterns in two wavelengths
Hu, Yao; Zeng, Lijiang; Li, Lifeng
2007-01-01
We propose an experimental method to coherently mosaic two planar diffraction gratings. The method uses a Twyman-Green interferometer to guarantee the planar parallelism of the two sub-aperture gratings, and obtains the in-plane rotational error and the two translational errors from analysis of the far-field diffraction intensity patterns in two alignment wavelengths. We adjust the relative attitude and position of the two sub-aperture gratings to produce Airy disk diffraction patterns in both wavelengths. In our experiment, the repeatability of in-plane rotation adjustment was 2.35 μrad and that of longitudinal adjustment was 0.11 μm. The accuracy of lateral adjustment was about 2.9% of the grating period.
International Nuclear Information System (INIS)
Vittal, K.P.R.; Subbiah, B.V.
1982-01-01
For the root distribution studies, methods are not available to measure the growth in situ and in toto under field conditions without destroying the plants. A non-destructive method was developed for measuring the gamma activity in root using a probe that was administered through the stem. Five isotopes viz. 86 Rb, 134 Cs, 59 Fe, 65 Zn and 54 Mn tested, were found to represent almost similar rooting pattern for pearl millet from flowering to harvesting stages. Among these isotopes 59 Fe was found to be suitable for field use. This method also enabled to successfully monitor the root activity over time and avoided the sampling errors. Since laboratory processing of samples was eliminated, the process of measurement was hastened. (author)
Surface magnetization and the role of pattern defects in various types of ripple patterned films
International Nuclear Information System (INIS)
Colino, Jose M; Arranz, Miguel A; Barbero, Antonio J; Bollero, A; Camarero, J
2016-01-01
We present a detailed study of the magnetic properties of cobalt films with wide-area nanoscale ripple patterns, either on their surface only, or on both the film surface and substrate interface. Angular dependence vectorial-resolved magnetometry measurements and magnetic force microscopy with in situ magnetic field have been used to determine the magnetization reversal processes to correlate them to the different patterned nanostructures. All the samples show well-defined uniaxial magnetic anisotropy with the anisotropy axis lying along the ripple direction. Atomic force microscopy of the different types of pattern reveals various pattern defects: height corrugation and breaks of continuity along the ripple direction, and overlapping ripples and Y-shaped defects (pattern dislocation) across the pattern. In spite of the existence of such customary defects of erosive-regime patterns, the type of low-amplitude, surface-patterned films remarkably behave as a macrospin over almost the whole in-plane angular range (340°), with negligible spread of anisotropy axis or energy. In turn, it is found that high-amplitude surface-patterned films develop an angular distribution of anisotropy axes, probably related to the large distribution of amplitudes in a pattern of short ripples, and a significant distribution of anisotropy fields ΔH k /H k up to 15%. On the other hand, films grow on pre-patterned silicon with a significantly longer mean ripple length, and develop a larger anisotropy energy with H k up to 110 mT, probably because of the double interface effect. The switching fields close to the magnetization easy axis of all types of ripple pattern are not well reproduced by the macrospin approximation, but the observed pattern defects seem to be not responsible for the domain wall pinning that occurs with the field applied along the ripple direction. (paper)
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Soglia, Maria da Conceicao M. [Universidade Federal da Bahia (UFBA), Cruz das Almas, BA (Brazil). Centro de Ciencias Agrarias e Ambientais], e-mail: mcsoglia@yahoo.com.br; Bueno, Vanda Helena Paes; Carvalho, Livia Mendes [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Entomologia], e-mail: vhpbueno@ufla.br
2007-10-15
This work aimed to evaluate the development time and the consumption of Orius insidiosus (Say, 1832) feeding on Aphis gossypii Glover, 1877 as well as its oviposition behavior on two chrysanthemum cut cultivars. The trials were conducted in climatic chamber at 25 {+-} 1 deg C, RH 70 {+-} 10% and 12h photo phase. Nymphs of the predator, less than 24h old, were kept individually in petri dishes (5cm) with 20 nymphs of A. gossypii (first, second and third instar) on leaf disc (4 cm) of each cultivar ('White Reagan' and 'Yellow Snowdon') in a layer of agar-water (1%). Petiole of each chrysanthemum cultivar as oviposition substrate was evaluated and the females were feeding on eggs of Anagasta kuehniella (Zeller, 1879). The predator complete its development feeding on A. gossypii kept in both cultivars. The duration of nymphal phase of O. insidiosus were 21.1 and 18.3 days on 'White Reagan' and 'Yellow Snowdon', respectively. The consumption of the females of O. insidiosus was higher (P<0.01) on A. gossypii in 'White Reagan' (2.63 nymphs) compared to the consumption in 'Yellow Snowdon' (0.7 nymphs). Females of O. insidiosus oviposited in petiole of both cultivars with 22.5 and 23.3 eggs/female on 'White Reagan' and 'Yellow Snowdon', respectively. Release of O. insidiosus on chrysanthemum crops could be important to decrease the A. gossypii population, as the predator completes its development having this aphid as prey, and the chrysanthemum cultivars offer conditions to colonization and establishment of O. insidiosus. (author)
Beveridge, C.; Kocurek, G.; Ewing, R.C.; Lancaster, N.; Morthekai, P.; Singhvi, A.K.; Mahan, S.A.
2006-01-01
The pattern of dunes within the Gran Desierto of Sonora, Mexico, is both spatially diverse and complex. Identification of the pattern components from remote-sensing images, combined with statistical analysis of their measured parameters demonstrate that the composite pattern consists of separate populations of simple dune patterns. Age-bracketing by optically stimulated luminescence (OSL) indicates that the simple patterns represent relatively short-lived aeolian constructional events since ???25 ka. The simple dune patterns consist of: (i) late Pleistocene relict linear dunes; (ii) degraded crescentic dunes formed at ???12 ka; (iii) early Holocene western crescentic dunes; (iv) eastern crescentic dunes emplaced at ???7 ka; and (v) star dunes formed during the last 3 ka. Recognition of the simple patterns and their ages allows for the geomorphic backstripping of the composite pattern. Palaeowind reconstructions, based upon the rule of gross bedform-normal transport, are largely in agreement with regional proxy data. The sediment state over time for the Gran Desierto is one in which the sediment supply for aeolian constructional events is derived from previously stored sediment (Ancestral Colorado River sediment), and contemporaneous influx from the lower Colorado River valley and coastal influx from the Bahia del Adair inlet. Aeolian constructional events are triggered by climatic shifts to greater aridity, changes in the wind regime, and the development of a sediment supply. The rate of geomorphic change within the Gran Desierto is significantly greater than the rate of subsidence and burial of the accumulation surface upon which it rests. ?? 2006 The Authors. Journal compilation 2006 International Association of Sedimentologists.
Natural quasy-periodic binary structure with focusing property in near field diffraction pattern.
Mihailescu, Mona
2010-06-07
A naturally-inspired phase-only diffractive optical element with a circular symmetry given by a quasi-periodic structure of the phyllotaxis type is presented in this paper. It is generated starting with the characteristic parametric equations which are optimal for the golden angle interval. For some ideal geometrical parameters, the diffracted intensity distribution in near-field has a central closed ring with almost zero intensity inside. Its radius and intensity values depend on the geometry or non-binary phase distribution superposed onto the phyllotaxis geometry. Along propagation axis, the transverse diffraction patterns from the binary-phase diffractive structure exhibit a self-focusing behavior and a rotational motion.
Mosquito larval productivity in rice-fields infested with Azolla in ...
African Journals Online (AJOL)
Abstract: Azolla (Salviniales: Azollaceae) is known to reduce oviposition and adult emergence of a number of mosquito species. Several species of Azolla are reportedly indigenous to Tanzania. However, the potential of Azolla as a biocontrol agent against malaria mosquitoes has not been evaluated in the country.
Characteristic precipitation patterns of El Niño/La Niña in time-variable gravity fields by GRACE
Morishita, Yu; Heki, Kosuke
2008-01-01
El Niño and La Niña are known to bring about characteristic patterns of anomalous precipitation in various regions of the world. We extracted temporary and regional gravity changes from monthly gravity fields recovered by the GRACE satellites, and converted them to the changes in surface mass, possibly ground or subsurface water in land area. Such mass changes in the 2006-2007 El Niño and 2005-2006 La Niña episodes agreed well with precipitation anomaly patterns inferred from meteorological r...
Zhang, Li; Zhang, Li; Wu, Dong-Xia; Zhang, Jun-Jun
2014-06-01
In order to clarify the effects of tillage patterns on farmland weed community structure and crop production characteristics, based on 10 years location experiment with no-tillage, subsoiling and conventional tillage in the cold and arid region of North China, and supplementary experiment of plowing after 10 years no-tillage and subsoiling, oat was planted in 2 soils under different tillage patterns, and field weed total density, dominant weed types, weed diversity index, field weed biomass and oats yield were measured. The results showed that the regional weed community was dominated by foxtail weed (Setaira viridis); the weed density under long-term no-tillage was 2.20-5.14 times of tillage at different growing stages of oat, but there were no significant differences between conditional tillage and plowing after long-term no-tillage and subsoiling. Field weed Shannon diversity indices were 0.429 and 0.531, respectively, for sandy chestnut soil and loamy meadow soil under no-tillage conditions, and field weed biomass values were 1.35 and 2.26 times of plowing treatment, while the oat biomass values were only 2807.4 kg x hm(-2) and 4053.9 kg x hm(-2), decreased by 22.3% and 46.2%, respectively. The results showed that the weed community characteristics were affected by both tillage patterns and soil types. Long-term no-tillage farmland in the cold and arid region of North China could promote the natural evolution of plant communities by keeping more perennial weeds, and the plowing pattern lowered the annual weed density, eliminated perennial weeds with shallow roots, and stimulated perennial weeds with deep roots.
Ayllón, Tania; Câmara, Daniel Cardoso Portela; Morone, Fernanda Cristina; Gonçalves, Larissa da Silva; Saito Monteiro de Barros, Fábio; Brasil, Patrícia; Carvalho, Marilia Sá; Honório, Nildimar Alves
2018-01-01
Aedes albopictus, originally considered as a secondary vector for arbovirus transmission, especially in areas where this species co-exist with Aedes aegypti, has been described in most regions of the world. Dispersion and domiciliation of Ae. albopictus in a complex of densely urbanized slums in Rio de Janeiro, Southeastern Brazil, was evidenced. In this study, we tested the hypotheses that 1) Ae. albopictus distribution in urban slums is negatively related to distance from vegetation, and 2) these vectors have taken on a domestic life style with a portion of the population feeding, ovipositing, and resting indoors. To do this, we developed an integrated surveillance proposal, aiming to detect the presence and abundance of Aedes mosquitoes. The study, based on a febrile syndrome surveillance system in a cohort of infants living in the slum complex, was performed on a weekly basis between February 2014 and April 2017. A total of 8,418 adult mosquitoes (3,052 Ae. aegypti, 44 Ae. albopictus, 16 Ae. scapularis, 4 Ae. fluviatilis and 5,302 Culex quinquefasciatus) were collected by direct aspiration and 46,047 Aedes spp. eggs were collected by oviposition traps. The Asian tiger mosquito, Ae. albopictus, was aspirated in its adult form (n = 44), and immature forms of this species (n = 12) were identified from the eggs collected by the ovitraps. In most collection sites, co-occurrence of Ae. aegypti and Ae. albopictus was observed. Key-sites, such as junkyards, thrift stores, factories, tire repair shops and garages, had the higher abundance of Ae. albopictus, followed by schools and households. We collected Ae. albopictus at up to 400 meters to the nearest vegetation cover. The log transformed (n+1) number of females Ae. albopictus captured at each collection point was inversely related to the distance to the nearest vegetation border. These results show that Ae. albopictus, a competent vector for important arboviruses and more commonly found in areas with higher
Fuji, Hiroshi; Kikukawa, Takashi; Tominaga, Junji
2004-07-01
Pit-edge recording at a density of 150 nm pits and spaces is carried out on a super-resolution near-field structure (super-RENS) disk with a platinum oxide layer. Pits are recorded and read using a 635-nm-wavelength laser and an objective lens with a 0.6 numerical aperture. We arrange laser pulses to correctly record the pits on the disk by a write-strategy technique. The laser-pulse figure includes a unit time of 0.25 T and intensities of Pw1, Pw2 and Pw3. After recording pits of various lengths, the observation of an eye pattern is achieved despite a pit smaller than the resolution limit. Furthermore, the eye pattern maintains its shape even though other pits fill the adjacent tracks at a track density of 600 nm. The disk can be used as a pit-edge recording system through a write-strategy technique.
Directory of Open Access Journals (Sweden)
B. C. Das
2011-12-01
Full Text Available Many studies indicate that there is a density of aphids below which ladybirds are unlikely to lay eggs. This is adaptive as theory indicates that a certain minimum population density of aphids is required if hatchling larvae are to survive. The responses of gravid females of the two spot ladybird, Adalia bipunctata (L. (Coleoptera: Coccinellidae, recorded over a period of an hour, to colonies of 5 and 50 pea aphids on bean plants and similar plants each previously infested with the same number of aphids for 48 hours were determined. Proportionally more of the ladybirds on plants with 50 aphids or that were previously infested with the same number of aphids for 48 hours laid eggs and larger clusters of eggs, and were less active than those on plants that were infested with or had previously been infested with five aphids. That is, gravid females showed similar oviposition and activity responses to aphid abundance and different levels of honeydew contamination. This indicates that honeydew contamination may be an important cue used by ladybirds when locating and assessing the abundance of prey in aphid colonies.
Alvarez, Jeff A.; Cook, David G.; Yee, Julie L.; van Hattem, Michael G.; Fong, Darren R.; Fisher, Robert N.
2013-01-01
We studied the microhabitat characteristics of 747 egg masses of the federally-threatened Rana draytonii (California red-legged frog) at eight sites in California. our study showed that a broad range of aquatic habitats are utilized by ovipositing R. draytonii, including sites with perennial and ephemeral water sources, natural and constructed wetlands, lentic and lotic hydrology, and sites surrounded by protected lands and nested within modified urban areas. We recorded 45 different egg mass attachment types, although the use of only a few types was common at each site. These attachment types ranged from branches and roots of riparian trees, emergent and submergent wetland vegetation, flooded upland grassland/ruderal vegetation, and debris. eggs were deposited in relatively shallow water (mean 39.7 cm) when compared to maximum site depths. We found that most frogs in artificial pond, natural creek, and artificial channel habitats deposited egg masses within one meter of the shore, while egg masses in a seasonal marsh averaged 27.3 m from the shore due to extensive emergent vegetation. Rana draytonii appeared to delay breeding in lotic habitats and in more inland sites compared to lentic habitats and coastal sites. eggs occurred as early as mid-december at a coastal artificial pond and as late as mid-April in an inland natural creek. We speculate that this delay in breeding may represent a method of avoiding high-flow events and/or freezing temperatures. Understanding the factors related to the reproductive needs of this species can contribute to creating, managing, or preserving appropriate habitat, and promoting species recovery.
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Shilei Liu
2017-07-01
Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.
Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong
2017-01-01
Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955
Ni, Xinzhi; Wilson, Jeffrey P; Toews, Michael D; Buntin, G David; Lee, R Dewey; Li, Xin; Lei, Zhongren; He, Kanglai; Xu, Wenwei; Li, Xianchun; Huffaker, Alisa; Schmelz, Eric A
2014-10-01
Spatial and temporal patterns of insect damage in relation to aflatoxin contamination in a corn field with plants of uniform genetic background are not well understood. After previous examination of spatial patterns of insect damage and aflatoxin in pre-harvest corn fields, we further examined both spatial and temporal patterns of cob- and kernel-feeding insect damage, and aflatoxin level with two samplings at pre-harvest in 2008 and 2009. The feeding damage by each of the ear/kernel-feeding insects (i.e., corn earworm/fall armyworm damage on the silk/cob, and discoloration of corn kernels by stink bugs) and maize weevil population were assessed at each grid point with five ears. Sampling data showed a field edge effect in both insect damage and aflatoxin contamination in both years. Maize weevils tended toward an aggregated distribution more frequently than either corn earworm or stink bug damage in both years. The frequency of detecting aggregated distribution for aflatoxin level was less than any of the insect damage assessments. Stink bug damage and maize weevil number were more closely associated with aflatoxin level than was corn earworm damage. In addition, the indices of spatial-temporal association (χ) demonstrated that the number of maize weevils was associated between the first (4 weeks pre-harvest) and second (1 week pre-harvest) samplings in both years on all fields. In contrast, corn earworm damage between the first and second samplings from the field on the Belflower Farm, and aflatoxin level and corn earworm damage from the field on the Lang Farm were dissociated in 2009. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
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Fernández-Trincado, J. G.; Geisler, D.; Tang, B.; Villanova, S.; Mennickent, R. E. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Zamora, O.; García-Hernández, D. A.; Dell’Agli, F.; Prieto, Carlos Allende [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Souto, Diogo; Cunha, Katia [Observatório Nacional, Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400 (Brazil); Schiavon, R. P. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Hasselquist, Sten [New Mexico State University, Las Cruces, NM 88003 (United States); Shetrone, M. [University of Texas at Austin, McDonald Observatory, Fort Davis, TX 79734 (United States); Vieira, K. [Centro de Investigaciones de Astronomía, AP 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Zasowski, G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Sobeck, J.; Hayes, C. R.; Majewski, S. R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22903 (United States); Placco, V. M., E-mail: jfernandezt@astro-udec.cl, E-mail: jfernandezt87@gmail.com [Department of Physics and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556 (United States); and others
2017-09-01
We report the peculiar chemical abundance patterns of 11 atypical Milky Way (MW) field red giant stars observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). These atypical giants exhibit strong Al and N enhancements accompanied by C and Mg depletions, strikingly similar to those observed in the so-called second-generation (SG) stars of globular clusters (GCs). Remarkably, we find low Mg abundances ([Mg/Fe] < 0.0) together with strong Al and N overabundances in the majority (5/7) of the metal-rich ([Fe/H] ≳ −1.0) sample stars, which is at odds with actual observations of SG stars in Galactic GCs of similar metallicities. This chemical pattern is unique and unprecedented among MW stars, posing urgent questions about its origin. These atypical stars could be former SG stars of dissolved GCs formed with intrinsically lower abundances of Mg and enriched Al (subsequently self-polluted by massive AGB stars) or the result of exotic binary systems. We speculate that the stars Mg-deficiency as well as the orbital properties suggest that they could have an extragalactic origin. This discovery should guide future dedicated spectroscopic searches of atypical stellar chemical patterns in our Galaxy, a fundamental step forward to understanding the Galactic formation and evolution.
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José Fernando Jurca Grigolli
2013-02-01
Full Text Available The feeding and oviposition behavior of boll weevil in new cotton cultivars is essential for an adequate management. The objective of this study was to evaluate the vertical distribution of squares punctured for feeding and oviposition of the pest in the cultivars NuOPAL, DeltaOPAL, FMT-701, FMX-910 and FMX-993, and record the most and least preferred times of feeding and oviposition. The number of squares used for boll weevil feeding and oviposition were evaluated weekly in three parts of plant canopy. It was observed that, regardless the cultivar, A. grandis preferred to lay eggs in squares located in the upper part and feed on squares in the middle and upper parts. The boll weevil preferred to feed on cultivar FMT-701 in the beginning of the period of cotton flowering and fruiting, and the cultivars NuOPAL, DeltaOPAL, FMX-910 and FMX-993 throughout the whole period of flowering and fruiting. A. grandis preferred to lay eggs on cultivars NuOPAL, FMT-701 and FMX-993 at the beginning and end of flowering and fruiting of plants, while the cultivars DeltaOPAL and FMX-910 are used for oviposition throughout the period of flowering and fruiting.O conhecimento do comportamento de alimentação e de oviposição de Anthonomus grandis em cultivares recentes de algodoeiro é essencial para seu manejo. Neste trabalho, objetivou-se avaliar a distribuição vertical de botões florais com orifícios de alimentação e de oviposição da praga nas cultivares NuOPAL, DeltaOPAL, FMT-701, FMX-910 e FMX-993, bem como registrar as épocas de maior e menor preferência alimentar e de oviposição. O experimento foi conduzido em Jaboticabal, SP, Brasil, safra 2010/2011. Foram realizadas avaliações semanais, baseadas no número de botões florais, utilizados para alimentação e para oviposição pelo bicudo-do-algodoeiro, em três regiões do dossel das plantas. Observou-se que A. grandis preferiu ovipositar em botões florais localizados no terço superior das
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Torsten Wappler
2015-04-01
Full Text Available The Paleozoic–Mesozoic transition is characterized by the most massive extinction of the Phanerozoic. Nevertheless, an impressive adaptive radiation of herbivorous insects occurred on gymnosperm-dominated floras not earlier than during the Middle to Late Triassic, penecontemporaneous with similar events worldwide, all which exhibit parallel expansions of generalized and mostly specialized insect herbivory on plants, expressed as insect damage on a various plant organs and tissues. The flora from Monte Agnello is distinctive, due to its preservation in subaerially deposited pyroclastic layers with exceptionally preserved details. Thus, the para-autochthonous assemblage provides insights into environmental disturbances, caused by volcanic activity, and how they profoundly affected the structure and composition of herbivory patterns. These diverse Middle Triassic biota supply extensive evidence for insect herbivore colonization, resulting in specific and complex herbivory patterns involving the frequency and diversity of 20 distinctive damage types (DTs. These DT patterns show that external foliage feeders, piercer-and-suckers, leaf miners, gallers, and oviposition culprits were intricately using almost all tissue types from the dominant host plants of voltzialean conifers (e.g., Voltzia, horsetails, ferns (e.g., Neuropteridium, Phlebopteris, Cladophlebis and Thaumatopteris, seed ferns (e.g., Scytophyllum, and cycadophytes (e.g., Bjuvia and Nilssonia.
Creating optimized machine working patterns on agricultural fields
Mark Spekken
2015-01-01
In the current agricultural context, agricultural machine unproductivity on fields and their impacts on soil along pathways are unavoidable. These machines have direct and indirect costs associated to their work in field, with non-productive time spent in manoeuvres when these are reaching field borders; likewise, there is a double application of product when machines are covering headlands while adding farm inputs. Both issues aggravate under irregular field geometry. Moreover, unproductive ...
Relationship between carrot weevil infestation and parsley yield.
Torres, Angel N; Hoy, Casey W
2005-08-01
The relationship between numbers of carrot weevil, Listronotus oregonensis (LeConte), oviposition scars and parsley fresh weight and plant mortality was measured in research plots during 1999 and 2000. Fresh weight was measured in one to two cuttings of parsley planted on two planting dates. The average weight declined with increasing numbers of oviposition scars in the later planting in 1999. Compensatory growth in surviving plants may reduce this effect. Plant mortality increased as number of oviposition scars per plant increased in the second planting in both years and in the first cutting of the first planting in 2000. One oviposition scar per plant is sufficient to result in significant reduction in fresh weight per plant. In commercial parsley fields, the relationship between fresh weight of parsley per 30-cm row section of parsley was best described as a linear function of the proportion of plants with root feeding. Economic damage to parsley that is equivalent to the cost of controlling carrot weevil was estimated to result from approximately 1% of plants with root damage. Based upon this estimated economic injury level, we suggest an action threshold of 1% of plants containing carrot weevil oviposition scars earlier in the growing season when controls could be applied to prevent the damage.
McLay, Lucy Katherine; Nagarajan-Radha, Venkatesh; Green, Mark Philip; Jones, Therésa Melanie
2018-05-07
Humans are lighting the night-time environment with ever increasing extent and intensity, resulting in a variety of negative ecological effects in individuals and populations. Effects of light at night on reproductive fitness traits are demonstrated across taxa however, the mechanisms underlying these effects are largely untested. One possible mechanism is that light at night may result in perturbed reactive oxygen species (ROS) and oxidative stress levels. Here, we reared Drosophila melanogaster under either dim (10 lx) light or no light (0 lx) at night for three generations and then compared mating and lifetime oviposition patterns. In a second experiment, we explored whether exposure to light at night treatments resulted in variation in ROS levels in the heads and ovaries of six, 23- and 36-day-old females. We demonstrate that dim light at night affects mating and reproductive output: 10 lx flies courted for longer prior to mating, and female oviposition patterns differed to 0 lx females. ROS levels were lower in the ovaries but not heads, of 10 lx compared with 0 lx females. We suggest that reduced ROS levels may reflect changes in ovarian physiology and cell signaling, which may be related to the differences observed in oviposition patterns. Taken together, our results indicate negative consequences for invertebrates under more stressful, urban, lit conditions and further investigation into the mechanisms driving these changes is warranted to manage invertebrate communities in a brighter future. © 2018 Wiley Periodicals, Inc.
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Kshitij Chandel
2016-12-01
Full Text Available The Asian tiger mosquito, Aedes albopictus, is a vector of dengue, Chikungunya, and Zika viruses. This mosquito inhabits a wide range of artificial water-holding containers in urban and suburban areas making it difficult to control. We tested the hypothesis that female-driven autodissemination of an insect growth regulator could penetrate cryptic oviposition habitats difficult to treat with conventional insecticidal sprays.Oviposition preferences of Ae. albopictus females for open and cryptic cups were tested in semi-field experiments. Two conventional larvicidal sprayers were tested to determine droplet penetration and larvicidal efficacy in open and cryptic habitats using Bacillus thuringiensis var. israelensis (Bti in the field. Finally, the efficacy of pyriproxyfen autodissemination stations was assessed in cryptic and open cups in residential areas during 2013 and 2014.Gravid females strongly preferred cryptic (53.1±12.9 eggs/cup over open (10.3±4.3 eggs/cup cups for oviposition. Cryptic cups showed limited droplet penetration and produced 0.1-0.3% larval mortality with a conventional backpack and low-volume sprays of Bti. The autodissemination stations effectively contaminated these cryptic cups (59.3-84.6% and produced 29.7-40.8% pupal mortality during 2013-2014. Significant pupal mortality was also observed in open cups.The autodissemination station effectively exploits the oviposition behavior of wild gravid females to deliver pyriproxyfen to targeted oviposition habitats. Although the pupal mortality in cryptic cups was relatively lower than expected for the effective vector control. Autodissemination approach may be a suitable supporting tool to manage Ae. albopictus immatures in the cryptic habitats those are less accessible to conventional larvicidal sprays.
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Anna A Rathé
Full Text Available In any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. The glassy-winged sharpshooter, Homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, Xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas and are considered to be highly invasive. Neither has been detected in Australia. Twelve Australian native plant species present in the USA were observed over two years for suitability as H. vitripennis feeding, oviposition and nymph development hosts. Hosts providing evidence of adult or nymph presence were Leptospermum laevigatum, Acacia cowleana, Eremophila divaricata, Eucalyptus wandoo, Hakea laurina, Melaleuca laterita and Swainsona galegifolia. An oviposition-suitability field study was conducted with citrus, a favoured oviposition host, as a positive control. Citrus and L. laevigatum, A. cowleana, B. ericifolia×B. spinulosa, C. pulchella, E. divaricata, E. wandoo, H. laurina, and S. galegifolia were found to be oviposition hosts. Egg parasitism by the mymarid parasitoid Gonatocerus ashmeadi was observed on all Australian plants. A number of Australian plants that may facilitate H. vitripennis invasion have been identified and categorised as 'high risk' due to their ability to support all three life stages (egg, nymph and adult of the insect in the field (L. laevigatum, A. cowleana, E. divaricata, H. laurina, and S. galegifolia. The implications of these host status and natural enemy research findings are discussed and placed in an Australian invasion context.
Kothari, Ruchi; Bokariya, Pradeep; Singh, Ramji; Singh, Smita; Narang, Purvasha
2014-01-01
To evaluate whether glaucomatous visual field defect particularly the pattern standard deviation (PSD) of Humphrey visual field could be associated with visual evoked potential (VEP) parameters of patients having primary open angle glaucoma (POAG). Visual field by Humphrey perimetry and simultaneous recordings of pattern reversal visual evoked potential (PRVEP) were assessed in 100 patients with POAG. The stimulus configuration for VEP recordings consisted of the transient pattern reversal method in which a black and white checker board pattern was generated (full field) and displayed on VEP monitor (colour 14″) by an electronic pattern regenerator inbuilt in an evoked potential recorder (RMS EMG EP MARK II). The results of our study indicate that there is a highly significant (P<0.001) negative correlation of P100 amplitude and a statistically significant (P<0.05) positive correlation of N70 latency, P100 latency and N155 latency with the PSD of Humphrey visual field in the subjects of POAG in various age groups as evaluated by Student's t-test. Prolongation of VEP latencies were mirrored by a corresponding increase of PSD values. Conversely, as PSD increases the magnitude of VEP excursions were found to be diminished.
Anselm, D; Danner, M; Kirmaier, N; König, H L; Müller-Limmroth, W; Reis, A; Schauerte, W
1977-06-10
In the relevant frequency range of about 10 Hertz cars can be considered very largely as Faraday cages and consequently as screens against air-electric fields. This may have a negative influence on driving and reaction patterns as a result. In an extensive investigation 48 subjects in a driving simulator were exposed to definite artificially produced air-electric fields. The self-rating of the performance and concentration of the subjects, reaction times and driving errors were determined. While the reaction times remained practically constant, the driving behavior of the subjects improved.
Directory of Open Access Journals (Sweden)
Nurcahyo Iman Prakoso
2017-12-01
Full Text Available Batrocera carambolae was one of the main pests in some types of fruits. This pest attack resulted in quantitative damage in the form of fall of young fruit and qualitatively in the form of fruit to rot and contains maggots. This research was conducted to determine selected extract from Andrographis Paniculata Ness, Piper betle Linn and Acacia auriculiformis leaves which have repellent activity for Batrocera carambolae. Nine extracts from the maceration process of the three leaves were evaluated by placing the extracts and flies together in the cage. The ethanol, ethyl acetate, and n-hexane extracts from Andrographis Paniculata Ness, Piper betle Linn and Acacia auriculiformis leaves were applied to the test pieces and fed into a cage containing 10 male and female flies. From observation, N-hexane extracts from Andrographis Paniculata Ness and Piper betle Linn leaves and ethyl acetate extracts from Acacia auriculiformis leaf having good activity as repellent and potentially to be used as a insect ovipositing repellent of Batrocera carambolae.
International Nuclear Information System (INIS)
Sudo, Seiichi; Yamamoto, Kazuki; Ishimoto, Yukitaka; Nix, Stephanie
2017-01-01
This paper describes the characteristics of water flow induced by the bridge oscillation of magnetic fluid between two permanent magnets subject to an external alternating magnetic field. The magnetic fluid bridge is formed in the space between a pair of identical coaxial cylindrical permanent magnets submerged in water. The direction of alternating magnetic field is parallel /antiparallel to the magnetic field produced by two permanent magnets. The magnetic fluid bridge responds to the external alternating magnetic field with harmonic oscillation. The oscillation of magnetic fluid bridge generates water flow around the bridge. Water flow is visualized using a thin milk film at the container bottom. Water flows are observed with a high-speed video camera analysis system. The experimental results show that the flow pattern induced by the bridge oscillation depends on the Keulegan–Carpenter number.
Energy Technology Data Exchange (ETDEWEB)
Sudo, Seiichi, E-mail: sudo@akita-pu.ac.jp [Faculty of Systems Science and Technology, Akita Prefectural University, Ebinokuchi 84-4, Yurihonjo 015-0055 (Japan); Yamamoto, Kazuki [Graduate School of Engineering, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Ishimoto, Yukitaka; Nix, Stephanie [Faculty of Systems Science and Technology, Akita Prefectural University, Ebinokuchi 84-4, Yurihonjo 015-0055 (Japan)
2017-06-01
This paper describes the characteristics of water flow induced by the bridge oscillation of magnetic fluid between two permanent magnets subject to an external alternating magnetic field. The magnetic fluid bridge is formed in the space between a pair of identical coaxial cylindrical permanent magnets submerged in water. The direction of alternating magnetic field is parallel /antiparallel to the magnetic field produced by two permanent magnets. The magnetic fluid bridge responds to the external alternating magnetic field with harmonic oscillation. The oscillation of magnetic fluid bridge generates water flow around the bridge. Water flow is visualized using a thin milk film at the container bottom. Water flows are observed with a high-speed video camera analysis system. The experimental results show that the flow pattern induced by the bridge oscillation depends on the Keulegan–Carpenter number.
EM Modeling of Far-Field Radiation Patterns for Antennas on the GMA-TT UAV
Mackenzie, Anne I.
2015-01-01
To optimize communication with the Generic Modular Aircraft T-Tail (GMA-TT) unmanned aerial vehicle (UAV), electromagnetic (EM) simulations have been performed to predict the performance of two antenna types on the aircraft. Simulated far-field radiation patterns tell the amount of power radiated by the antennas and the aircraft together, taking into account blockage by the aircraft as well as radiation by conducting and dielectric portions of the aircraft. With a knowledge of the polarization and distance of the two communicating antennas, e.g. one on the UAV and one on the ground, and the transmitted signal strength, a calculation may be performed to find the strength of the signal travelling from one antenna to the other and to check that the transmitted signal meets the receiver system requirements for the designated range. In order to do this, the antenna frequency and polarization must be known for each antenna, in addition to its design and location. The permittivity, permeability, and geometry of the UAV components must also be known. The full-wave method of moments solution produces the appropriate dBi radiation pattern in which the received signal strength is calculated relative to that of an isotropic radiator.
Analysis of Radiation Field and Block Pattern for Optimal Size in Multileaf Collimator
International Nuclear Information System (INIS)
Ahn, Seoung Do; Yang, Kwang Mo; Yi, Byong Yong; Choi, Eun Kyong; Chang, Hye Sook
1994-01-01
The patterns of the conventional radiation treatment fields and their shielding blocks are analysed to determine the optimal dimension of the MultiLeaf Collimator (MLC) which is considered as an essential tool for conformal therapy. Total 1169 radiation fields from 303 patients (203 from Asan Medical center, 50 from Baek Hosp and 50 from Hanyang Univ. Hosp.) were analysed for this study. Weighted case selection treatment site (from The Korean Society of Therapeutic Radiology 1003). Ninety one percent of total fields have shielding blocks. Y axis is defined as leaf movement direction and it is assumed that MLC is installed on the cranial-caudal direction. The length of X axis were distributed from 4cm to 40cm (less than 21cm for 95% of cases), and Y axis from 5cm to 38cm (less than 22cm for 95% of cases). The shielding blocks extended to less than 6cm from center of the filed for 95% of the cases. Start length for ninety five percent of block is less than 10cm for X axis and 11cm for Y axis. Seventy six percent of shielding blocks could be placed by either X or Y axis direction, 7.9% only by Y axis, 5.1% only by X axis and it is reasonable to install MLC for Y direction. Ninety five percent of patients can be treated with coplanar rotation therapy without changing the collimator angle. Eleven percent of cases of cases were impossible to replace with MLC. Futher study of shielding should be larger than 21cm X 22cm. The MLC should be designed as a pair of 21 leaves with 1cm wide for an acceptable resolution and 17cm long to enable the leaf to overtravel at least 6cm from the treatment field center
Wallingford, Anna K; Cha, Dong H; Linn, Charles E; Wolfin, Michael S; Loeb, Gregory M
2017-10-01
In agricultural settings, examples of effective control strategies using repellent chemicals in integrated pest management (IPM) are relatively scarce compared to those using attractants. This may be partly due to a poor understanding of how repellents affect insect behavior once they are deployed. Here we attempt to identify potential hallmarks of repellent stimuli that are robust enough for practical use in the field. We explore the literature for success stories using repellents in IPM and we investigate the mechanisms of repellency for two chemical oviposition deterrents for controlling Drosophila suzukii Matsumura, a serious pest of small fruit crops. Drosophila suzukii causes injury by laying her eggs in ripening fruit and resulting larvae make fruit unmarketable. In caged choice tests, reduced oviposition was observed in red raspberry fruit treated with volatile 1-octen-3-ol and geosmin at two initial concentrations (10% and 1%) compared to untreated controls. We used video monitoring to observe fly behavior in these caged choice tests and investigate the mode of action for deterrence through the entire behavioral repertoire leading to oviposition. We observed fewer visitors and more time elapsed before flies first landed on 1-octen-3-ol-treated fruits than control fruits and concluded that this odor primarily inhibits behaviors that occur before D. suzukii comes in contact with a potential oviposition substrate (precontact). We observed some qualitative differences in precontact behavior of flies around geosmin-treated fruits; however, we concluded that this odor primarily inhibits behaviors that occur after D. suzukii comes in contact with treated fruits (postcontact). Field trials found reduced oviposition in red raspberry treated with 1-octen-3-ol and a combination of 1-octen-3-ol and geosmin, but no effect of geosmin alone. Recommendations for further study of repellents for practical use in the field are discussed. © The Authors 2017. Published by
Directory of Open Access Journals (Sweden)
Ruchi Kothari
2014-04-01
Full Text Available AIM:To evaluate whether glaucomatous visual field defect particularly the pattern standard deviation (PSD of Humphrey visual field could be associated with visual evoked potential (VEP parameters of patients having primary open angle glaucoma (POAG.METHODS:Visual field by Humphrey perimetry and simultaneous recordings of pattern reversal visual evoked potential (PRVEP were assessed in 100 patients with POAG. The stimulus configuration for VEP recordings consisted of the transient pattern reversal method in which a black and white checker board pattern was generated (full field and displayed on VEP monitor (colour 14” by an electronic pattern regenerator inbuilt in an evoked potential recorder (RMS EMG EP MARK II.RESULTS:The results of our study indicate that there is a highly significant (P<0.001 negative correlation of P100 amplitude and a statistically significant (P<0.05 positive correlation of N70 latency, P100 latency and N155 latency with the PSD of Humphrey visual field in the subjects of POAG in various age groups as evaluated by Student’s t-test.CONCLUSION:Prolongation of VEP latencies were mirrored by a corresponding increase of PSD values. Conversely, as PSD increases the magnitude of VEP excursions were found to be diminished.
Analytic models for beam propagation and far-field patterns in slab and bow-tie x-ray lasers
International Nuclear Information System (INIS)
Chandler, E.A.
1994-06-01
Simplified analytic models for beam propagation in slab and bow-tie x-ray lasers yield convenient expressions that provide both a framework for guidance in computer modeling and useful approximates for experimenters. In unrefracted bow-tie lasers, the laser shape in conjunction with the nearly-exponential weighting of rays according to their length produces a small effective aperture for the signal. We develop an analytic expression for the aperture and the properties of the far-field signal. Similarly, we develop the view that the far-field pattern of refractive slab lasers is the result of effective apertures that are created by the interplay of refraction and exponential amplification. We present expressions for the size of this aperture as a function of laser parameters as well as for the intensity and position of the far-field lineout. This analysis also yields conditions for the refraction limit in slab lasers and an estimate for the signal loss due to refraction
Schmitz, Oliver; Beelen, Rob M. J.; de Bakker, Merijn P.; Karssenberg, Derek
2015-04-01
Constructing spatio-temporal numerical models to support risk assessment, such as assessing the exposure of humans to air pollution, often requires the integration of field-based and agent-based modelling approaches. Continuous environmental variables such as air pollution are best represented using the field-based approach which considers phenomena as continuous fields having attribute values at all locations. When calculating human exposure to such pollutants it is, however, preferable to consider the population as a set of individuals each with a particular activity pattern. This would allow to account for the spatio-temporal variation in a pollutant along the space-time paths travelled by individuals, determined, for example, by home and work locations, road network, and travel times. Modelling this activity pattern requires an agent-based or individual based modelling approach. In general, field- and agent-based models are constructed with the help of separate software tools, while both approaches should play together in an interacting way and preferably should be combined into one modelling framework, which would allow for efficient and effective implementation of models by domain specialists. To overcome this lack in integrated modelling frameworks, we aim at the development of concepts and software for an integrated field-based and agent-based modelling framework. Concepts merging field- and agent-based modelling were implemented by extending PCRaster (http://www.pcraster.eu), a field-based modelling library implemented in C++, with components for 1) representation of discrete, mobile, agents, 2) spatial networks and algorithms by integrating the NetworkX library (http://networkx.github.io), allowing therefore to calculate e.g. shortest routes or total transport costs between locations, and 3) functions for field-network interactions, allowing to assign field-based attribute values to networks (i.e. as edge weights), such as aggregated or averaged
Directory of Open Access Journals (Sweden)
Ricardo Castillo-Neyra
2015-01-01
Full Text Available Chagas disease affects millions of people in Latin America. The control of this vector-borne disease focuses on halting transmission by reducing or eliminating insect vector populations. Most transmission of Trypanosoma cruzi, the causative agent of Chagas disease, involves insects living within or very close to households and feeding mostly on domestic animals. As animal hosts can be intermittently present it is important to understand how host availability can modify transmission risk to humans and to characterize the host-seeking dispersal of triatomine vectors on a very fine scale. We used a semi-field system with motion-detection cameras to characterize the dispersal of Triatoma infestans, and compare the behavior of vector populations in the constant presence of hosts (guinea pigs, and after the removal of the hosts. The emigration rate - net insect population decline in original refuge - following host removal was on average 19.7% of insects per 10 days compared to 10.2% in constant host populations (p = 0.029. However, dispersal of T. infestans occurred in both directions, towards and away from the initial location of the hosts. The majority of insects that moved towards the original location of guinea pigs remained there for 4 weeks. Oviposition and mortality were observed and analyzed in the context of insect dispersal, but only mortality was higher in the group where animal hosts were removed (p-value <0.01. We discuss different survival strategies associated with the observed behavior and its implications for vector control. Removing domestic animals in infested areas increases vector dispersal from the first day of host removal. The implications of these patterns of vector dispersal in a field setting are not yet known but could result in movement towards human rooms.
Directory of Open Access Journals (Sweden)
Christopher J Topping
Full Text Available Pattern-oriented modeling (POM is a general strategy for modeling complex systems. In POM, multiple patterns observed at different scales and hierarchical levels are used to optimize model structure, to test and select sub-models of key processes, and for calibration. So far, POM has been used for developing new models and for models of low to moderate complexity. It remains unclear, though, whether the basic idea of POM to utilize multiple patterns, could also be used to test and possibly develop existing and established models of high complexity. Here, we use POM to test, calibrate, and further develop an existing agent-based model of the field vole (Microtus agrestis, which was developed and tested within the ALMaSS framework. This framework is complex because it includes a high-resolution representation of the landscape and its dynamics, of the individual's behavior, and of the interaction between landscape and individual behavior. Results of fitting to the range of patterns chosen were generally very good, but the procedure required to achieve this was long and complicated. To obtain good correspondence between model and the real world it was often necessary to model the real world environment closely. We therefore conclude that post-hoc POM is a useful and viable way to test a highly complex simulation model, but also warn against the dangers of over-fitting to real world patterns that lack details in their explanatory driving factors. To overcome some of these obstacles we suggest the adoption of open-science and open-source approaches to ecological simulation modeling.
Directory of Open Access Journals (Sweden)
A.Y.A. Alkindi
2002-06-01
Full Text Available The aim of this study is to investigate the role of plasma level parameters during nesting activity and provide data potentially useful to future studies on the dynamics of reproductive and stress hormones in the most endangered sea turtle species in the world. Plasma parameters in the sea turtles, olive ridley (Lipodochelys oliveacea and hawksbill (Eretmochelys imbricata from Masirah Island, Oman, were analyzed relative to nesting stress. To date, no study has been conducted on plasma parameter levels in sea turtles during nesting. Field observations were conducted under ideal temperature conditions. At the time of sampling, there was no significant difference for cloacal, sand, air or water temperature for the two species. Electrolytes (Cl¯, Ca++, K+, Na+ and Mg++, cholesterol, urea, uric acid and osmolarity were measured during nesting. Both species were observed to spend between 1.5 and 2.00 hours on the nesting grounds. Some had successful oviposition and completed all nesting phases, while others with incomplete nesting phases failed to oviposit their eggs. Under both conditions, the turtles of both species had an exhaustive and stressful nesting exercise. Plasma parameter values, both intra-specifically and inter-specifically, were not significantly different for oviposited and non-oviposited turtles. This may indicate that both species have the same physiological adjustment relative to plasma parameters whether or not the turtles oviposited their eggs.
Abid, Abdulbasit
2013-03-01
This paper presents a thorough discussion of the proposed field-programmable gate array (FPGA) implementation for fringe pattern demodulation using the one-dimensional continuous wavelet transform (1D-CWT) algorithm. This algorithm is also known as wavelet transform profilometry. Initially, the 1D-CWT is programmed using the C programming language and compiled into VHDL using the ImpulseC tool. This VHDL code is implemented on the Altera Cyclone IV GX EP4CGX150DF31C7 FPGA. A fringe pattern image with a size of 512×512 pixels is presented to the FPGA, which processes the image using the 1D-CWT algorithm. The FPGA requires approximately 100 ms to process the image and produce a wrapped phase map. For performance comparison purposes, the 1D-CWT algorithm is programmed using the C language. The C code is then compiled using the Intel compiler version 13.0. The compiled code is run on a Dell Precision state-of-the-art workstation. The time required to process the fringe pattern image is approximately 1 s. In order to further reduce the execution time, the 1D-CWT is reprogramed using Intel Integrated Primitive Performance (IPP) Library Version 7.1. The execution time was reduced to approximately 650 ms. This confirms that at least sixfold speedup was gained using FPGA implementation over a state-of-the-art workstation that executes heavily optimized implementation of the 1D-CWT algorithm.
Magnetic Assisted Colloidal Pattern Formation
Yang, Ye
Pattern formation is a mysterious phenomenon occurring at all scales in nature. The beauty of the resulting structures and myriad of resulting properties occurring in naturally forming patterns have attracted great interest from scientists and engineers. One of the most convenient experimental models for studying pattern formation are colloidal particle suspensions, which can be used both to explore condensed matter phenomena and as a powerful fabrication technique for forming advanced materials. In my thesis, I have focused on the study of colloidal patterns, which can be conveniently tracked in an optical microscope yet can also be thermally equilibrated on experimentally relevant time scales, allowing for ground states and transitions between them to be studied with optical tracking algorithms. In particular, I have focused on systems that spontaneously organize due to particle-surface and particle-particle interactions, paying close attention to systems that can be dynamically adjusted with an externally applied magnetic or acoustic field. In the early stages of my doctoral studies, I developed a magnetic field manipulation technique to quantify the adhesion force between particles and surfaces. This manipulation technique is based on the magnetic dipolar interactions between colloidal particles and their "image dipoles" that appear within planar substrate. Since the particles interact with their own images, this system enables massively parallel surface force measurements (>100 measurements) in a single experiment, and allows statistical properties of particle-surface adhesion energies to be extracted as a function of loading rate. With this approach, I was able to probe sub-picoNewton surface interactions between colloidal particles and several substrates at the lowest force loading rates ever achieved. In the later stages of my doctoral studies, I focused on studying patterns formed from particle-particle interaction, which serve as an experimental model of
Statistical Pattern Recognition
Webb, Andrew R
2011-01-01
Statistical pattern recognition relates to the use of statistical techniques for analysing data measurements in order to extract information and make justified decisions. It is a very active area of study and research, which has seen many advances in recent years. Applications such as data mining, web searching, multimedia data retrieval, face recognition, and cursive handwriting recognition, all require robust and efficient pattern recognition techniques. This third edition provides an introduction to statistical pattern theory and techniques, with material drawn from a wide range of fields,
Directory of Open Access Journals (Sweden)
Mario A. Navarro-Silva
2009-01-01
Full Text Available The choice for suitable places for female mosquitoes to lay eggs is a key-factor for the survival of immature stages (eggs and larvae. This knowledge stands out in importance concerning the control of disease vectors. The selection of a place for oviposition requires a set of chemical, visual, olfactory and tactile cues that interact with the female before laying eggs, helping the localization of adequate sites for oviposition. The present paper presents a bibliographic revision on the main aspects of semiochemicals in regard to mosquitoes' oviposition, aiding the comprehension of their mechanisms and estimation of their potential as a tool for the monitoring and control of the Culicidae.A seleção de locais adequados pelas fêmeas de mosquitos para depositarem seus ovos é um fator chave para a sobrevivência de seus imaturos (ovos e larvas. O conhecimento das relações ecológicas implicadas neste processo é de grande importância quando se refere a vetores de agentes patogênicos. A determinação do local de oviposição pelas fêmeas grávidas envolve uma rede de mensagens químicas, visuais, olfativas e táteis que facilitam a localização de lugares adequados para depositarem seus ovos. Neste trabalho é apresentada uma revisão bibliográfica dos principais aspectos relacionados com semioquímicos presentes na oviposição dos mosquitos auxiliando no entendimento dos mecanismos de atuação dos mesmos e potencializando a aplicação destes semioquímicos como uma possível ferramenta de monitoramento e controle de Culicidae.
O'Brien, J K; Schmitt, T L; Nollens, H H; Dubach, J M; Robeck, T R
2016-01-01
Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10week period, commencing at 5weeks prior to egg lay (EL), to increase our understanding of the species' reproductive biology. Females in cordoned nest sites underwent cloacal artificial insemination (AI) every 4-7days with different semen donors for each insemination. The EL interval was 97.9±3.6h (range: 84-108h) and paternity analyses revealed that conceptive inseminations occurred from 11.5 to 4.5days before oviposition. A biphasic pattern of estradiol, testosterone, progesterone and the biochemical analytes triglyceride, iron, calcium and phosphorus occurred in relation to EL, with values increasing (P<0.05) to maximal concentrations during the three weeks preceding oviposition, then decreasing (P<0.05) rapidly after oviposition completion. In comparison with post-lay (baseline) values, concentrations of estradiol and testosterone relative to the first oviposition were elevated at Week-5, and those of triglyceride, a yolk formation index, as well as iron, calcium and phosphorus, became elevated at Week-4 (P<0.05). Collective data indicate an estimated total egg formation interval of 29days, with oviducal transit of the ovulated ovum occurring over the majority of the ∼4day EL interval. These findings indicate that egg formation is prolonged with folliculogenesis initiated at 5weeks or more prior to oviposition. Consequently, the period of folliculogenesis and egg formation is estimated to overlap with the final ∼3weeks that wild females spend at sea prior to returning to land for breeding. Copyright © 2015 Elsevier Inc. All rights reserved.
Wu, Ke; Hoy, Marjorie A.
2014-01-01
Clathrin heavy chain has been shown to be important for viability, embryogenesis, and RNA interference (RNAi) in arthropods such as Drosophila melanogaster. However, the functional roles of clathrin heavy chain in chelicerate arthropods, such as the predatory mite Metaseiulus occidentalis, remain unknown. We previously showed that dsRNA ingestion, followed by feeding on spider mites, induced systemic and robust RNAi in M. occidentalis females. In the current study, we performed a loss-of-function analysis of the clathrin heavy chain gene in M. occidentalis using RNAi. We showed that ingestion of clathrin heavy chain dsRNA by M. occidentalis females resulted in gene knockdown and reduced longevity. In addition, clathrin heavy chain dsRNA treatment almost completely abolished oviposition by M. occidentalis females and the few eggs produced did not hatch. Finally, we demonstrated that clathrin heavy chain gene knockdown in M. occidentalis females significantly reduced a subsequent RNAi response induced by ingestion of cathepsin L dsRNA. The last finding suggests that clathrin heavy chain may be involved in systemic RNAi responses mediated by orally delivered dsRNAs in M. occidentalis. PMID:25329675
International Nuclear Information System (INIS)
Cumnock, J.A.; Heelis, R.A.; Hairston, M.R.
1992-01-01
Ionospheric convection signatures observed over the polar regions are provided by the DMSP F8 satellite. The authors consider five passes over the southern summer hemisphere during a time when the z component of the interplantary magnetic field was stable and positive and the y component changed slowly from positive to negative. Large-scale regions of sunward flow are observed at very high latitudes consistent with a strong z component. When B y and B z are positive, but B y is greater than B z , strong evidence exists for dayside merging in a manner similar to that expected when B z is negative. This signature is diminished as B y decreases and becomes smaller than B z resulting in a four-cell convection pattern displaced toward the sunward side of the dawn-dusk meridian. In this case the sign of B y affects the relative sizes of the two highest-latitude cells. In the southern hemisphere the duskside high-latitude cell is dominant for B y positive and the dawnside high-latitude cell is dominant for B y negative. The relative importance of possible electric field sources in the low-latitude boundary layer, the dayside cusp, and the lobe all need to be considered to adequately explain the observed evolution of the convection pattern
Aigner, B L; Kuhar, T P; Herbert, D A; Brewster, C C; Hogue, J W; Aigner, J D
2017-04-01
The invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an important pest of soybean (Glycine max L. Merr.) in the Mid-Atlantic United States. In order to assess the influence of nonmanaged wooded borders on H. halys infestation patterns in soybean, 12 soybean fields in Orange and Madison Counties, VA, were sampled each week from July to October in 2013 or 2014 for H. halys. At each location, five 2-min visual counts of H. halys life stages were made on tree of heaven (Ailanthus altissima Mill.) and other favorable host trees along a wooded border, on the adjacent soybean edge, 15 m into the soybean field, and 30 m into the field. Seasonal data showed a clear trend at all locations of H. halys densities building up on A. altissima-dominated wooded borders in July, then, gradually moving into adjacent soybean field edges later in the summer. Halyomorpha halys did not move far from the invading field edge, with approximately half as many bugs being present at 15 m into the field and very few being detected 30 m into the field. These results have implications for continued monitoring and management using field border sprays, particularly on edges adjacent to woods. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Energy Technology Data Exchange (ETDEWEB)
Hung, Yung-Jr, E-mail: yungjrhung@gmail.com [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Department of Photonics, National Sun Yat-sen University, No. 70, Lienhai Rd., Kaohsiung 80424, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Lee, San-Liang [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Beng, Looi Choon [Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia); Chang, Hsuan-Chen [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Huang, Yung-Jui [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Lee, Kuei-Yi; Huang, Ying-Sheng [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China)
2014-04-01
Top-down fabrication strategies are proposed and demonstrated to realize arrays of vertically-aligned silicon nanowire bundles and bundle arrays of carbon nanotube–silicon nanowire (CNT–SiNW) heterojunctions, aiming for releasing the electrostatic screening effect and improving the field emission characteristics. The trade-off between the reduction in the electrostatic screening effect and the decrease of emission sites leads to an optimal SiNW bundle arrangement which enables the lowest turn-on electric field of 1.4 V/μm and highest emission current density of 191 μA/cm{sup 2} among all testing SiNW samples. Benefiting from the superior thermal and electrical properties of CNTs and the flexible patterning technologies available for SiNWs, bundle arrays of CNT–SiNW heterojunctions show improved and highly-uniform field emission with a lower turn-on electric field of 0.9 V/μm and higher emission current density of 5.86 mA/cm{sup 2}. The application of these materials and their corresponding fabrication approaches is not limited to the field emission but can be used for a variety of emerging fields like nanoelectronics, lithium-ion batteries, and solar cells. - Highlights: • Aligned silicon nanowire (SiNW) bundle arrays are realized with top-down methods. • Growing carbon nanotubes atop SiNW bundle arrays enable uniform field emission. • A turn-on field of 0.9 V/μm and an emission current of > 5 mA/cm{sup 2} are achieved.
International Nuclear Information System (INIS)
Murray, W.S.; Ziemba, F.; Szluk, N.
1998-01-01
RangerMaster trademark is the embedded firmware for Quantrad Sensor's integrated nuclear instrument package, the Ranger trademark. The Ranger trademark, which is both a gamma-ray and neutron detection system, was originally developed at Los Alamos National Laboratory for in situ surveys at the Plutonium Facility to confirm the presence of nuclear materials. The new RangerMaster trademark software expands the library of isotopes and simplifies the operation of the instrument by providing an easy mode suitable for untrained operators. The expanded library of the Ranger trademark now includes medical isotopes 99 Tc, 201 Tl, 111 In, 67 Ga, 133 Xe, 103 Pa, and 131 I; industrial isotopes 241 Am, 57 Co, 133 Ba, 137 Cs, 40 K, 60 Co, 232 Th, 226 Ra, and 207 Bi; and nuclear materials 235 U, 238 U, 233 U, and 239 Pu. To accomplish isotopic identification, a simulated spectrum for each of the isotopes was generated using SYNTH. The SYNTH spectra formed the basis for the knowledge-based expert system and selection of the regions of interest that are used in the pattern recognition system. The knowledge-based pattern recognition system was tested against actual spectra under field conditions
RangerMasterTM: real-time pattern recognition software for in-field analysis of radiation sources
International Nuclear Information System (INIS)
Murray, W.S.; Ziemba, F.; Szluk, N.
1998-01-01
RangerMaster TM is the embedded firmware for Quantrad Sensor's integrated nuclear instrument package, the Ranger TM . The Ranger TM , which is both a gamma-ray and neutron detection system, was originally developed at Los Alamos National Laboratory for in situ surveys at the Plutonium Facility to confirm the presence of nuclear materials. The new RangerMaster TM software expands the library of isotopes and simplifies the operation of the instrument by providing an 'easy' mode suitable for untrained operators. The expanded library of the Ranger TM now includes medical isotopes 99 Tc, 201 Tl, 111 In, 67 Ga, 133 Xe, 103 Pa, and 131 I; industrial isotopes 241 Am, 57 Co, 133 Ba, 137 Cs, 40 K, 60 Co, 232 Th, 226 Ra, and 207 Bi; and nuclear materials 235 U, 238 U, 233 U, and 239 Pu. To accomplish isotopic identification, a simulated spectrum for each of the isotopes was generated using SYNTH 2 . The SYNTH spectra formed the basis for the knowledge-based expert system and selection of the regions of interest that are used in the pattern recognition system. The knowledge-based pattern recognition system was tested against actual spectra under field conditions. (author)
Pottmann, Helmut; Huang, Qixing; Deng, Bailin; Schiftner, Alexander; Kilian, Martin; Guibas, Leonidas J.; Wallner, Johannes
2010-01-01
Geodesic curves in surfaces are not only minimizers of distance, but they are also the curves of zero geodesic (sideways) curvature. It turns out that this property makes patterns of geodesics the basic geometric entity when dealing with the cladding of a freeform surface with wooden panels which do not bend sideways. Likewise a geodesic is the favored shape of timber support elements in freeform architecture, for reasons of manufacturing and statics. Both problem areas are fundamental in freeform architecture, but so far only experimental solutions have been available. This paper provides a systematic treatment and shows how to design geodesic patterns in different ways: The evolution of geodesic curves is good for local studies and simple patterns; the level set formulation can deal with the global layout of multiple patterns of geodesics; finally geodesic vector fields allow us to interactively model geodesic patterns and perform surface segmentation into panelizable parts. © 2010 ACM.
Pottmann, Helmut
2010-07-26
Geodesic curves in surfaces are not only minimizers of distance, but they are also the curves of zero geodesic (sideways) curvature. It turns out that this property makes patterns of geodesics the basic geometric entity when dealing with the cladding of a freeform surface with wooden panels which do not bend sideways. Likewise a geodesic is the favored shape of timber support elements in freeform architecture, for reasons of manufacturing and statics. Both problem areas are fundamental in freeform architecture, but so far only experimental solutions have been available. This paper provides a systematic treatment and shows how to design geodesic patterns in different ways: The evolution of geodesic curves is good for local studies and simple patterns; the level set formulation can deal with the global layout of multiple patterns of geodesics; finally geodesic vector fields allow us to interactively model geodesic patterns and perform surface segmentation into panelizable parts. © 2010 ACM.
Directory of Open Access Journals (Sweden)
Nurcahyo Iman Prakoso
2018-03-01
Full Text Available Batrocera carambolae was one of the main pests in some types of fruits. This pest attack resulted in quantitative damage in the form of fall of young fruit and qualitatively in the form of fruit to rot and contains maggots. This research was conducted to determine selected extract from Andrographis Paniculata Ness, Piper betle Linn and Acacia auriculiformis leaves which have repellent activity for Batrocera carambolae. Nine extracts from the maceration process of the three leaves were evaluated by placing the extracts and flies together in the cage. The ethanol, ethyl acetate, and n-hexane extracts from Andrographis Paniculata Ness, Piper betle Linn and Acacia auriculiformis leaves were applied to the test pieces and fed into a cage containing 10 male and female flies. From observation, N-hexane extracts from Andrographis Paniculata Ness and Piper betle Linn leaves and ethyl acetate extracts from Acacia auriculiformis leaf having good activity as repellent and potentially to be used as a insect ovipositing repellent of Batrocera carambolae.
Crist, E. P. (Principal Investigator)
1982-01-01
An overall approach to crop spectral understanding is presented which serves to maintain a strong link between actual plant responses and characteristics and spectral observations from ground based and spaceborne sensors. A specific technique for evaluating field reflectance data, as a part of the overall approach, is also described. Results of the application of this technique to corn and soybeans reflectance data collected by and at Purdue/LARS indicate that a number of common cultural and environmental factors can significantly affect the temporal spectral development patterns of these crops in tasseled cap greenness (a transformed variable of LANDSAT MSS signals).
Energy Technology Data Exchange (ETDEWEB)
Rudolph, M.; Carr, S. M.; Ten Eyck, G.; Dominguez, J.; Carroll, M. S.; Bussmann, E. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Subramania, G. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Lilly, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Pluym, T.
2014-10-20
Recently, a single atom transistor was deterministically fabricated using phosphorus in Si by H-desorption lithography with a scanning tunneling microscope (STM). This milestone in precision, achieved by operating the STM in the conventional tunneling mode, typically utilizes slow (∼10{sup 2} nm{sup 2}/s) patterning speeds. By contrast, using the STM in a high-voltage (>10 V) field-emission mode, patterning speeds can be increased by orders of magnitude to ≳10{sup 4} nm{sup 2}/s. We show that the rapid patterning negligibly affects the functionality of relatively large micron-sized features, which act as contacting pads for these devices. For nanoscale structures, we show that the resulting electrical transport is consistent with the donor incorporation chemistry constraining the electrical dimensions to a scale of 10 nm even though the pattering spot size is 40 nm.
Kahl, Johannes; Busscher, Nicolaas; Mergardt, Gaby; Mäder, Paul; Torp, Torfinn; Ploeger, Angelika
2015-01-01
There is a need for authentication tools in order to verify the existing certification system. Recently, markers for analytical authentication of organic products were evaluated. Herein, crystallization with additives was described as an interesting fingerprint approach which needs further evidence, based on a standardized method and well-documented sample origin. The fingerprint of wheat cultivars from a controlled field trial is generated from structure analysis variables of crystal patterns. Method performance was tested on factors such as crystallization chamber, day of experiment and region of interest of the patterns. Two different organic treatments and two different treatments of the non-organic regime can be grouped together in each of three consecutive seasons. When the k-nearest-neighbor classification method was applied, approximately 84% of Runal samples and 95% of Titlis samples were classified correctly into organic and non-organic origin using cross-validation. Crystallization with additive offers an interesting complementary fingerprint method for organic wheat samples. When the method is applied to winter wheat from the DOK trial, organic and non-organic treated samples can be differentiated significantly based on pattern recognition. Therefore crystallization with additives seems to be a promising tool in organic wheat authentication. © 2014 Society of Chemical Industry.
Random scalar fields and hyperuniformity
Ma, Zheng; Torquato, Salvatore
2017-06-01
Disordered many-particle hyperuniform systems are exotic amorphous states of matter that lie between crystals and liquids. Hyperuniform systems have attracted recent attention because they are endowed with novel transport and optical properties. Recently, the hyperuniformity concept has been generalized to characterize two-phase media, scalar fields, and random vector fields. In this paper, we devise methods to explicitly construct hyperuniform scalar fields. Specifically, we analyze spatial patterns generated from Gaussian random fields, which have been used to model the microwave background radiation and heterogeneous materials, the Cahn-Hilliard equation for spinodal decomposition, and Swift-Hohenberg equations that have been used to model emergent pattern formation, including Rayleigh-Bénard convection. We show that the Gaussian random scalar fields can be constructed to be hyperuniform. We also numerically study the time evolution of spinodal decomposition patterns and demonstrate that they are hyperuniform in the scaling regime. Moreover, we find that labyrinth-like patterns generated by the Swift-Hohenberg equation are effectively hyperuniform. We show that thresholding (level-cutting) a hyperuniform Gaussian random field to produce a two-phase random medium tends to destroy the hyperuniformity of the progenitor scalar field. We then propose guidelines to achieve effectively hyperuniform two-phase media derived from thresholded non-Gaussian fields. Our investigation paves the way for new research directions to characterize the large-structure spatial patterns that arise in physics, chemistry, biology, and ecology. Moreover, our theoretical results are expected to guide experimentalists to synthesize new classes of hyperuniform materials with novel physical properties via coarsening processes and using state-of-the-art techniques, such as stereolithography and 3D printing.
Frequent Pattern Mining Algorithms for Data Clustering
DEFF Research Database (Denmark)
Zimek, Arthur; Assent, Ira; Vreeken, Jilles
2014-01-01
that frequent pattern mining was at the cradle of subspace clustering—yet, it quickly developed into an independent research field. In this chapter, we discuss how frequent pattern mining algorithms have been extended and generalized towards the discovery of local clusters in high-dimensional data......Discovering clusters in subspaces, or subspace clustering and related clustering paradigms, is a research field where we find many frequent pattern mining related influences. In fact, as the first algorithms for subspace clustering were based on frequent pattern mining algorithms, it is fair to say....... In particular, we discuss several example algorithms for subspace clustering or projected clustering as well as point out recent research questions and open topics in this area relevant to researchers in either clustering or pattern mining...
Spatiotemporal expression profile of the Pumilio gene in the embryonic development of silkworm.
Chen, Liang; You, Zaizhi; Xia, Hengchuan; Tang, Qi; Zhou, Yang; Yao, Qin; Chen, Keping
2014-01-01
We previously identified a pumilio gene in silkworm (Bombyx mori L.), designated BmPUM, which was specifically expressed in the ovary and testis. To further characterize this gene's involvement in silkworm development, we have determined the spatiotemporal expression pattern of BmPUM during all embryonic stages. Real-time polymerase chain reaction (RT-PCR) analysis revealed that BmPUM was expressed in all stages of silkworm embryos and that its transcript levels displayed two distinct peaks. The first was observed at the germ-band formation stage (1 d after oviposition) and dropped to a low level at the gonad formation stage (5 d after oviposition). The second was detected at the stage of bristle follicle occurrence (6 d after oviposition), which was confirmed by Western blot analysis and immunohistochemistry. Nanos (Nos), functioning together with Pum in abdomen formation of Drosophila embryos, was also highly expressed at the beginning (0 h to 1 d after oviposition) of embryogenesis, but its transcript levels were very low after the stage of germ-band formation. These results suggest that BmPUM functions with Bombyx mori nanos (Bm-nanos) at the early stages of silkworm embryonic development, and may then play a role in gonad formation and the occurrence of bristle follicles. Our data thus provide a foundation to uncover the role of BmPUM during silkworm development.
Patterns of geographic expansion of Aedes aegypti in the Peruvian Amazon.
Directory of Open Access Journals (Sweden)
Sarah Anne Guagliardo
2014-08-01
Full Text Available In the Peruvian Amazon, the dengue vector Aedes aegypti is abundant in large urban centers such as Iquitos. In recent years, it has also been found in a number of neighboring rural communities with similar climatic and socioeconomic conditions. To better understand Ae. aegypti spread, we compared characteristics of communities, houses, and containers in infested and uninfested communities.We conducted pupal-demographic surveys and deployed ovitraps in 34 communities surrounding the city of Iquitos. Communities surveyed were located along two transects: the Amazon River and a 95 km highway. We calculated entomological indices, mapped Ae. aegypti presence, and developed univariable and multivariable logistic regression models to predict Ae. aegypti presence at the community, household, or container level.Large communities closer to Iquitos were more likely to be infested with Ae. aegypti. Within infested communities, houses with Ae. aegypti had more passively-filled containers and were more often infested with other mosquito genera than houses without Ae. aegypti. For containers, large water tanks/drums and containers with solar exposure were more likely to be infested with Ae. aegypti. Maps of Ae. aegypti presence revealed a linear pattern of infestation along the highway, and a scattered pattern along the Amazon River. We also identified the geographical limit of Ae. aegypti expansion along the highway at 19.3 km south of Iquitos.In the Peruvian Amazon, Ae. aegypti geographic spread is driven by human transportation networks along rivers and highways. Our results suggest that urban development and oviposition site availability drive Ae. aegypti colonization along roads. Along rivers, boat traffic is likely to drive long-distance dispersal via unintentional transport of mosquitoes on boats.
Schmitz, R. G.; Alves, M. V.; Barbosa, M. V. G.
2017-12-01
One of the most important processes that occurs in Earth's magnetosphere is known as magnetic reconnection (MR). This process can be symmetric or asymmetric, depending basically on the plasma density and magnetic field in both sides of the current sheet. A good example of symmetric reconnection in terrestrial magnetosphere occurs in the magnetotail, where these quantities are similar on the north and south lobes. In the dayside magnetopause MR is asymmetric, since the plasma regimes and magnetic fields of magnetosheath and magnetosphere are quite different. Symmetric reconnection has some unique signatures. For example, the formation of a quadrupolar structure of Hall magnetic field and a bipolar Hall electric field that points to the center of the current sheet. The different particle motions in the presence of asymmetries change these signatures, causing the quadrupolar pattern to be distorted and forming a bipolar structure. Also, the bipolar Hall electric field is modified and gives rise to a single peak pointing toward the magnetosheat, considering an example of magnetopause reconnection. The presence of a guide-field can also distort the quadrupolar pattern, by giving a shear angle across the current sheet and altering the symmetric patterns, according to previous simulations and observations. Recently, a quadrupolar structure was observed in an asymmetric guide-field MR event using MMS (Magnetospheric Multiscale) mission data [Peng et al., JGR, 2017]. This event shows clearly that the density asymmetry and the guide-field were not sufficient to form signatures of asymmetric reconnection. Using the particle-in-cell code iPIC3D [Markidis et al, Mathematics and Computers in Simulation, 2010] with the MMS data from this event used to define input parameters, we found a quadrupolar structure of Hall magnetic field and a bipolar pattern of Hall electric field in ion scales, showing that our results are in an excellent agreement with the MMS observations. To our
Directory of Open Access Journals (Sweden)
Carolina L. Cañete
2003-01-01
Full Text Available Trichogramma atopovirilia Oatman & Platner is an egg parasitoid of the corn earworm Helicoverpa zea (Boddie (Lepidoptera, Noctuidae, and has recently been collected from eggs of Anticarsia gemmatalis Hübner on soybeans. In order to evaluate the suitability of A. gemmatalis eggs as hosts of T. atopovirilia, field surveys were conducted in 1999 and 2000 on corn and soybeans, and a colony of the parasitoid was established in laboratory. At 25 ºC, development from oviposition to emergence lasted nine days and a sex-ratio of 0.58 (females:males was obtained. Females lived significantly longer (11.4 days when kept in ovipositional activity, than in the absence of host eggs (6.6 days. Total fecundity averaged 104.5 parasitized eggs, resulting in the emergence of 138.3 descendents. Mean daily fecundity was highest (30 eggs/female on the first day. Oviposition continued until one day before the death of the females, however 70% of the eggs were laid during the first four days after emergence. A female-biased progeny was produced during the first three days of oviposition, whereas further ovipositions were male-biased. Females lived significantly longer when exposed to host eggs in comparison to females deprived of eggs. The results show that eggs of A. gemmatalis are suitable for the development of T. atopovirilia, and this parasitoid should be considered in future programs of biological control of the velvetbean caterpillar.
Novel Electrochemical Phenomena in Magnetic Fields(Research in High Magnetic Fields)
Mogi, Iwao; Kamiko, Masao
1996-01-01
Recent two topics are given of electrochemical studies in steady magnetic fields at the High Field Laboratory of Tohoku University. One is the magnetic-field-induced diffusion-limited-aggregation in the pattern formation of silver electrodeposits . The other is the magnetic field effect on the learning effect in a dopant-exchange process of an organic conducting polymer polypyrrole.
Polar cap electric field structures with a northward interplanetary magnetic field
International Nuclear Information System (INIS)
Burke, W.J.; Kelley, M.C.; Sagalyn, R.C.; Smiddy, M.; Lai, S.T.
1979-01-01
Polar cap electric fields patterns are presented from times when the S3-2 Satellite was near the dawn-dusk meridian and IMF data were available. With B/sub z/> or =0.7γ, two characteristic types of electric field patterns were measured in the polar cap. In the sunlit polar cap the convection pattern usually consisted of four cells. Two of the cells were confined to the polar cap with sunward convection in the central portion of the cap. The other pair of cells were marked by anti-sunward flow along the flanks of the polar cap and by sunward flow in the auroral oval. These observations are interpreted in terms of a model for magnetic merging at the poleward wall of the dayside polar cusp. The sunward flow in the auroral zone is not predicted by the magnetic model and may be due to a viscous interaction between the solar wind and and magnetosphere. The second type, which was observed in some of the summer hemisphere passes and all of the winter ones, was characterized by an electric field pattern which was very turbulent, and may be related to inhomogeneous merging
Observations on the Biology of Callosobruchus maculatus (Fab ...
African Journals Online (AJOL)
Observations on the biology of Callosobruchus maculatus( Fab.) were carried out under ambient laboratory conditions. Pattern of oviposition, female adult longevity and F1 progeny emergence in Callosobruchus maculatus ( Fab. ) were observed. The results showed that over 60% of the total number of eggs was laid during ...
Patterning via optical saturable transitions
Cantu, Precious
For the past 40 years, optical lithography has been the patterning workhorse for the semiconductor industry. However, as integrated circuits have become more and more complex, and as device geometries shrink, more innovative methods are required to meet these needs. In the far-field, the smallest feature that can be generated with light is limited to approximately half the wavelength. This, so called far-field diffraction limit or the Abbe limit (after Prof. Ernst Abbe who first recognized this), effectively prevents the use of long-wavelength photons >300nm from patterning nanostructures barrier is developed and experimentally verified. This approach, which I refer to as Patterning via Optical Saturable Transitions (POST) has the potential for massive parallelism, enabling the creation of nanostructures and devices at a speed far surpassing what is currently possible with conventional optical lithographic techniques. The fundamental understanding of this technique goes beyond optical lithography in the semiconductor industry and is applicable to any area that requires the rapid patterning of large-area two or three-dimensional complex geometries. At a basic level, this research intertwines the fields of electrochemistry, material science, electrical engineering, optics, physics, and mechanical engineering with the goal of developing a novel super-resolution lithographic technique.
Sandt, Carol H.; Fedorka-Cray, Paula J.; Tewari, Deepanker; Ostroff, Stephen; Joyce, Kevin; M’ikanatha, Nkuchia M.
2013-01-01
Salmonellosis is one of the most important foodborne diseases affecting humans. To characterize the relationship between Salmonella causing human infections and their food animal reservoirs, we compared pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility patterns of non-typhoidal Salmonella isolated from ill humans in Pennsylvania and from food animals before retail. Human clinical isolates were received from 2005 through 2011 during routine public health operations in Pennsylvania. Isolates from cattle, chickens, swine and turkeys were recovered during the same period from federally inspected slaughter and processing facilities in the northeastern United States. We found that subtyping Salmonella isolates by PFGE revealed differences in antimicrobial susceptibility patterns and, for human Salmonella, differences in sources and invasiveness that were not evident from serotyping alone. Sixteen of the 20 most common human Salmonella PFGE patterns were identified in Salmonella recovered from food animals. The most common human Salmonella PFGE pattern, Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS), was associated with more cases of invasive salmonellosis than all other patterns. In food animals, this pattern was almost exclusively (99%) found in Salmonella recovered from chickens and was present in poultry meat in every year of the study. Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS) was associated with susceptibility to all antimicrobial agents tested in 94.7% of human and 97.2% of food animal Salmonella isolates. In contrast, multidrug resistance (resistance to three or more classes of antimicrobial agents) was observed in five PFGE patterns. Typhimurium patterns JPXX01.0003 (JPXX01.0003 ARS) and JPXX01.0018 (JPXX01.0002 ARS), considered together, were associated with resistance to five or more classes of antimicrobial agents: ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in 92% of human and 80% of food
Directory of Open Access Journals (Sweden)
Allan Crema
2004-06-01
Full Text Available A migração é um fenômeno que pode ocorrer em algumas espécies de insetos e ela geralmente começa quando os ovários não estão desenvolvidos, ou o estão parcialmente. Para traça-das-crucíferas, Plutella xylostella (Lepidoptera: Yponomeutidae já foi observado que a densidade larval afetou o grau de desenvolvimento ovariano. Neste trabalho foi determinado o impacto da temperatura e do fotoperíodo no desenvolovimento ovariano e na oviposição do inseto. Larvas de quarto estágio foram criadas individualmente em placas de Petri à temperaturas de 14 e 25ºC e fotofase de 8 e 14 h. As fêmeas recém-emergidas foram mortas em um freezer, dissecadas sob um microscópio e o ovário observado. Para determinar o impacto da temperatura sobre a oviposição do inseto, larvas de quarto estágio foram criadas a temperaturas de 14 e 25ºC e, quando os machos e fêmeas emergiram, casais foram colocados individualmente em placas de Petri. Foi determinado o período de pré-oviposição e o número de ovos depositados no primeiro dia. Os resultados mostraram que o grau de desenvolvimento ovariano não foi afetado pela temperatura e fotoperíodo empregados, indicando que estes fatores não afetaram o potencial migratório da espécie. Fêmeas criadas a 25ºC depositaram seus ovos dois dias após a emergência enquanto que fêmeas criadas a 14ºC o fizeram aos cinco dias, sugerindo que o período de pré-oviposição é aumentado a baixas temperaturas. O impacto destes resultados sobre a migração e dispersão da TDC são discutidos.Migration occurs in some insect species, and in many cases it commences when the ovaries are immature. Environmental conditions can affect the rate of ovarian development and oviposition of insects. In the Diamondback Moth (DBM, Plutella xylostella (Lepidoptera: Yponomeutidae, the larval density affected the rate of ovarian development. In this work we determined the impact of temperatures and photoperiods on DBM ovarian
Applying and Developing Patterns in Teaching
DEFF Research Database (Denmark)
Bennedsen, Jens; Eriksen, Ole
2003-01-01
A community of teachers and researchers within computer science has adopted the idea of patterns and developed a set of pedagogical patterns. These patterns capture best practices in teaching. From our research and teaching practice we have observed that pedagogical patterns are useful...... enriches the notion of pedagogical patterns. Inspired by conditions for learning we identify three values in teaching in the field of engineering-related educations. Further we present a value-based template for guidelines in teaching, causing a better understanding of the patterns and help teachers...
Wright, Jennifer A; Larson, Ryan T; Richardson, Alec G; Cote, Noel M; Stoops, Craig A; Clark, Marah; Obenauer, Peter J
2015-03-01
The BG-Sentinel® (BGS) trap and oviposition cups (OCs) have both proven effective in the surveillance of Aedes species. This study aimed to determine which of the 2 traps could best characterize the relative population sizes of Aedes albopictus and Aedes aegypti in an urban section of Jacksonville, FL. Until 1986, Ae. aegypti was considered the dominant container-breeding species in urban northeastern Florida. Since the introduction of Ae. albopictus, Ae. aegypti has become almost completely extirpated. In 2011, a resurgence of Ae. aegypti was detected in the urban areas of Jacksonville; thus this study initially set out to determine the extent of Ae. aegypti reintroduction to the area. We determined that the BGS captured a greater number of adult Ae. aegypti than Ae. albopictus, while OCs did not monitor significantly different numbers of either species, even in areas where the BGS traps suggested a predominance of one species over the other. Both traps were effective at detecting Aedes spp.; however, the BGS proved more diverse by detecting over 20 other species as well. Our results show that in order to accurately determine vectorborne disease threats and the impact of control operations on these 2 species, multiple trapping techniques should be utilized when studying Ae. aegypti and Ae. albopictus population dynamics.
On Discrete Killing Vector Fields and Patterns on Surfaces
Ben-Chen, Mirela
2010-09-21
Symmetry is one of the most important properties of a shape, unifying form and function. It encodes semantic information on one hand, and affects the shape\\'s aesthetic value on the other. Symmetry comes in many flavors, amongst the most interesting being intrinsic symmetry, which is defined only in terms of the intrinsic geometry of the shape. Continuous intrinsic symmetries can be represented using infinitesimal rigid transformations, which are given as tangent vector fields on the surface - known as Killing Vector Fields. As exact symmetries are quite rare, especially when considering noisy sampled surfaces, we propose a method for relaxing the exact symmetry constraint to allow for approximate symmetries and approximate Killing Vector Fields, and show how to discretize these concepts for generating such vector fields on a triangulated mesh. We discuss the properties of approximate Killing Vector Fields, and propose an application to utilize them for texture and geometry synthesis. Journal compilation © 2010 The Eurographics Association and Blackwell Publishing Ltd.
Aranson, Igor S
2009-01-01
This title presents a review of experiments and novel theoretical concepts needed to understand the mechanisms of pattern formation in granular materials. An effort is made to connect concepts and ideas developed in granular physics with new emergent fields, especially in biology, such as cytoskeleton dynamics.
DEFF Research Database (Denmark)
Bygstad, Bendik; Nielsen, Peter Axel; Munkvold, Bjørn Erik
2010-01-01
This paper aims to contribute to a theory of integration within the field of IS project management. Integration is a key IS project management issue when new systems are developed and implemented into an increasingly integrated information infrastructure in corporate and governmental organizations....... Expanding the perspective of traditional project management research, we draw extensively on central insights from IS research. Building on socio-technical IS research and Software Engineering research we suggest four generic patterns of integration: Big Bang, Stakeholder Integration, Technical Integration...... and Socio-Technical Integration. We analyze and describe the advantages and disadvantages of each pattern. The four patterns are ideal types. To explore the forces and challenges in these patterns three longitudinal case studies were conducted. In particular we investigate the management challenges for each...
McTrusty, Alice D; Cameron, Lorraine A; Perperidis, Antonios; Brash, Harry M; Tatham, Andrew J; Agarwal, Pankaj K; Murray, Ian C; Fleck, Brian W; Minns, Robert A
2017-09-01
We compared patterns of visual field loss detected by standard automated perimetry (SAP) to saccadic vector optokinetic perimetry (SVOP) and examined patient perceptions of each test. A cross-sectional study was done of 58 healthy subjects and 103 with glaucoma who were tested using SAP and two versions of SVOP (v1 and v2). Visual fields from both devices were categorized by masked graders as: 0, normal; 1, paracentral defect; 2, nasal step; 3, arcuate defect; 4, altitudinal; 5, biarcuate; and 6, end-stage field loss. SVOP and SAP classifications were cross-tabulated. Subjects completed a questionnaire on their opinions of each test. We analyzed 142 (v1) and 111 (v2) SVOP and SAP test pairs. SVOP v2 had a sensitivity of 97.7% and specificity of 77.9% for identifying normal versus abnormal visual fields. SAP and SVOP v2 classifications showed complete agreement in 54% of glaucoma patients, with a further 23% disagreeing by one category. On repeat testing, 86% of SVOP v2 classifications agreed with the previous test, compared to 91% of SAP classifications; 71% of subjects preferred SVOP compared to 20% who preferred SAP. Eye-tracking perimetry can be used to obtain threshold visual field sensitivity values in patients with glaucoma and produce maps of visual field defects, with patterns exhibiting close agreement to SAP. Patients preferred eye-tracking perimetry compared to SAP. This first report of threshold eye tracking perimetry shows good agreement with conventional automated perimetry and provides a benchmark for future iterations.
Sims, David W; Humphries, Nicolas E; Bradford, Russell W; Bruce, Barry D
2012-03-01
1. Search processes play an important role in physical, chemical and biological systems. In animal foraging, the search strategy predators should use to search optimally for prey is an enduring question. Some models demonstrate that when prey is sparsely distributed, an optimal search pattern is a specialised random walk known as a Lévy flight, whereas when prey is abundant, simple Brownian motion is sufficiently efficient. These predictions form part of what has been termed the Lévy flight foraging hypothesis (LFF) which states that as Lévy flights optimise random searches, movements approximated by optimal Lévy flights may have naturally evolved in organisms to enhance encounters with targets (e.g. prey) when knowledge of their locations is incomplete. 2. Whether free-ranging predators exhibit the movement patterns predicted in the LFF hypothesis in response to known prey types and distributions, however, has not been determined. We tested this using vertical and horizontal movement data from electronic tagging of an apex predator, the great white shark Carcharodon carcharias, across widely differing habitats reflecting different prey types. 3. Individual white sharks exhibited movement patterns that predicted well the prey types expected under the LFF hypothesis. Shark movements were best approximated by Brownian motion when hunting near abundant, predictable sources of prey (e.g. seal colonies, fish aggregations), whereas movements approximating truncated Lévy flights were present when searching for sparsely distributed or potentially difficult-to-detect prey in oceanic or shelf environments, respectively. 4. That movement patterns approximated by truncated Lévy flights and Brownian behaviour were present in the predicted prey fields indicates search strategies adopted by white sharks appear to be the most efficient ones for encountering prey in the habitats where such patterns are observed. This suggests that C. carcharias appears capable of exhibiting
On Discrete Killing Vector Fields and Patterns on Surfaces
Ben-Chen, Mirela; Butscher, Adrian; Solomon, Justin; Guibas, Leonidas
2010-01-01
, and show how to discretize these concepts for generating such vector fields on a triangulated mesh. We discuss the properties of approximate Killing Vector Fields, and propose an application to utilize them for texture and geometry synthesis. Journal
Zahouli, Julien B Z; Utzinger, Jürg; Adja, Maurice A; Müller, Pie; Malone, David; Tano, Yao; Koudou, Benjamin G
2016-09-29
Aedes mosquito-transmitted outbreaks of dengue and yellow fever have been reported from rural and urban parts of Côte d'Ivoire. The present study aimed at assessing Aedes spp. oviposition ecology in variously urbanized settings within arbovirus foci in southeastern Côte d'Ivoire. Aedes spp. eggs were sampled using a standard ovitrap method from January 2013 to April 2014 in different ecosystems of rural, suburban and urban areas. Emerged larvae were reared until the adult stage for species identification. Aedes spp. oviposition ecology significantly varied from rural-to-urban areas and according to the ecozones and the seasons. Species richness of Aedes spp. gradually decreased from rural (eight species) to suburban (three species) and urban (one species) areas. Conversely, emerged adult Aedes spp. mean numbers were higher in the urban (1.97 Aedes/ovitrap/week), followed by the suburban (1.44 Aedes/ovitrap/week) and rural (0.89 Aedes/ovitrap/week) areas. Aedes aegypti was the only species in the urban setting (100 %), and was also the predominant species in suburban (85.5 %) and rural (63.3 %) areas. The highest Ae. aegypti mean number was observed in the urban (1.97 Ae. aegypti/ovitrap/week), followed by the suburban (1.20 Ae. aegypti/ovitrap/week) and rural (0.57 Ae. aegypti/ovitrap/week) areas. Aedes africanus (9.4 %), Ae. dendrophilus (8.0 %), Ae. metallicus (1.3 %) in the rural, and Ae. vittatus (6.5 %) and Ae. metallicus (1.2 %) in the suburban areas each represented more than 1 % of the total Aedes fauna. In all areas, Aedes species richness and abundance were higher in the peridomestic zones and during the rainy season, with stronger variations in species richness in the rural and in abundance in the urban areas. Besides, the highest Culex quinquefasciatus abundance was found in the urban areas, while Eretmapodites chrysogaster was restricted to the rural areas. Urbanization correlates with a substantially higher abundance in Aedes mosquitoes and
Evolution of wave patterns and temperature field in shock-tube flow
Kiverin, A. D.; Yakovenko, I. S.
2018-05-01
The paper is devoted to the numerical analysis of wave patterns behind a shock wave propagating in a tube filled with a gaseous mixture. It is shown that the flow inside the boundary layer behind the shock wave is unstable, and the way the instability develops fully corresponds to the solution obtained for the boundary layer over a flat plate. Vortical perturbations inside the boundary layer determine the nonuniformity of the temperature field. In turn, exactly these nonuniformities define the way the ignition kernels arise in the combustible mixture after the reflected shock interaction with the boundary layer. In particular, the temperature nonuniformity determines the spatial limitations of probable ignition kernel position relative to the end wall and side walls of the tube. In the case of low-intensity incident shocks the ignition could start not farther than the point of first interaction between the reflected shock wave and roller vortices formed in the process of boundary layer development. Proposed physical mechanisms are formulated in general terms and can be used for interpretation of the experimental data in any systems with a delayed exothermal reaction start. It is also shown that contact surface thickening occurs due to its interaction with Tollmien-Schlichting waves. This conclusion is of importance for understanding the features of ignition in shock tubes operating in the over-tailored regime.
Pattern formation in optical resonators
International Nuclear Information System (INIS)
Weiss, C O; Larionova, Ye
2007-01-01
We review pattern formation in optical resonators. The emphasis is on 'particle-like' structures such as vortices or spatial solitons. On the one hand, similarities impose themselves with other fields of physics (condensed matter, phase transitions, particle physics, fluds/super fluids). On the other hand the feedback is led by the resonator mirrors to bi- and multi-stability of the spatial field structure, which is the basic ingredient for optical information processing. The spatial dimension or the 'parallelism' is the strength of optics compared to electronics (and will have to be employed to fully use the advantages optics offers in information processing). But even in the 'serial' processing tasks of telecoms (e.g. information buffering) spatial resonator solitons can do better than the schemes proposed so far-including 'slow light'. Pattern formation in optical resonators will likely be the key to brain-like information processing like cognition, learning and association; to complement the precise but limited algorithmic capabilities of electronic processing. But even in the short term it will be useful for solving serial optical processing problems. The prospects for technical uses of pattern formation in resonators are one motivation for this research. The fundamental similarities with other fields of physics, on the other hand, inspire transfer of concepts between fields; something that has always proven fruitful for gaining deeper insights or for solving technical problems
Directory of Open Access Journals (Sweden)
Kitherian Sahayaraj
2012-03-01
Full Text Available We investigated the role of a brown seaweed alga, Sargassum tenerrimum (J. Agardh, against Dysdercus cingulatus (Fab., which is an economically important cotton pest in many parts of Asia. Sargassum tenerrimum has been used as a source of fertilizers and drugs, but there is no information available in the literature about its use in ecofriendly pest management. The impact of benzene (BN, chloroform (CH, and a mixture of benzene and chloroform (BNCH extracts, as well as two chromatographic fractions of BNCH (FR1 and FR2 were investigated for their insecticidal and ovipositional properties against D. cingulatus. The BE extract showed the best insecticidal activity (LC50 = 0.009%, higher than BNCH (LC50 = 0.021% and CH extracts (LC50 = 0.2481%, and all the extracts reduced the total nymphal developmental period of the pest in a dose-dependent way. Adult longevity of both males and females was reduced by the CH and BE extracts. The CH extract reduced D. cingulatus oviposition, preoviposition, and post-oviposition periods, as well as fecundity. Females emerging from the BE category could not lay eggs. All the extracts significantly reduced both total body protein and genomic DNA content. The BECH fractions, FR1 and FR2, also exhibited nymphicidal activity against the pest. However, these fractions did not significantly alter the nymphal developmental period. Results indicate that these seaweed extracts can be used as biopesticides for pest management.Investigamos el rol de una alga marina café, Sargassum tenerrimum (J. Agardh, contra Dysdercus cingulatus (Fab., una plaga económicamente importante del algodón en muchas partes de Asia. Sargassum tenerrimum ha sido usada como fuente de fertilizantes y drogas, pero en la literatura no hay información disponible sobre su uso en manejo de plagas ecoamigable. Se investigó el impacto de extractos con benceno (BN, cloroformo (CH, y una mezcla de ambos (BNCH así como dos fracciones cromatográficas de
Dynamic Skin Patterns in Cephalopods
Directory of Open Access Journals (Sweden)
Martin J. How
2017-06-01
Full Text Available Cephalopods are unrivaled in the natural world in their ability to alter their visual appearance. These mollusks have evolved a complex system of dermal units under neural, hormonal, and muscular control to produce an astonishing variety of body patterns. With parallels to the pixels on a television screen, cephalopod chromatophores can be coordinated to produce dramatic, dynamic, and rhythmic displays, defined collectively here as “dynamic patterns.” This study examines the nature, context, and potential functions of dynamic patterns across diverse cephalopod taxa. Examples are presented for 21 species, including 11 previously unreported in the scientific literature. These range from simple flashing or flickering patterns, to highly complex passing wave patterns involving multiple skin fields.
Dynamic Skin Patterns in Cephalopods
How, Martin J.; Norman, Mark D.; Finn, Julian; Chung, Wen-Sung; Marshall, N. Justin
2017-01-01
Cephalopods are unrivaled in the natural world in their ability to alter their visual appearance. These mollusks have evolved a complex system of dermal units under neural, hormonal, and muscular control to produce an astonishing variety of body patterns. With parallels to the pixels on a television screen, cephalopod chromatophores can be coordinated to produce dramatic, dynamic, and rhythmic displays, defined collectively here as “dynamic patterns.” This study examines the nature, context, and potential functions of dynamic patterns across diverse cephalopod taxa. Examples are presented for 21 species, including 11 previously unreported in the scientific literature. These range from simple flashing or flickering patterns, to highly complex passing wave patterns involving multiple skin fields. PMID:28674500
Reproductive Plasticity of an Invasive Insect Pest, Rice Water Weevil (Coleoptera: Curculionidae).
Huang, Yunshang; Ao, Yan; Jiang, Mingxing
2017-12-05
Reproductive plasticity is a key determinant of species invasiveness. However, there are a limited number of studies addressing this issue in exotic insects. The rice water weevil Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), which is native to North America, is one of the most invasive insect pests in east Asia. In this study, we investigated the reproductive status of first-generation females (progeny of overwintered weevils) from five geographic regions in southern and northern China in the field, and reproductive status and ovipositional features of females provided with suitable host plants in the laboratory after collection. Under field conditions, a proportion of females oviposited, while the rest remained in diapause from all three southern regions investigated, but reproductive development did not take place in females from the two northern regions, where the weevil produces only one generation per year. However, when fed host plants in the laboratory, females from all regions laid eggs. They typically had a very short ovipositional period (3-6 d on average on rice at a temperature of 27°C), laid a low number of eggs, and did not die soon after oviposition; this was different from common reproductive females. We concluded that first-generation L. oryzophilus females, which largely enter diapause after emergence, are highly plastic in their reproductive performance and are ready to reproduce under favorable conditions. Our results indicate the significance of their reproductive plasticity for geographic spread and population development. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Directory of Open Access Journals (Sweden)
Marilene Fancelli
2008-12-01
Full Text Available Diversos métodos têm sido empregados para avaliar a resistência de plantas a moscas-brancas. Todavia, poucos trabalhos têm sido realizados visando determinar a dispersão de ninfas desses insetos sobre as plantas. O objetivo do presente trabalho foi avaliar a oviposição de B. tabaci biótipo B e a dispersão de suas ninfas em folíolos com e sem exsudatos de genótipos de tomateiro. Foram utilizados sete genótipos de tomateiro: LA716, LA1739, PI134417, LA462, LA1584, 'Santa Clara' e P25 (controle suscetível. A oviposição de B. tabaci biótipo B foi avaliada em gaiolas plásticas (2,8 cm² fixadas na face abaxial dos folíolos, nas quais foram inseridos dez casais do inseto. Para avaliação da dispersão das ninfas, considerou-se o deslocamento dos insetos além do limite da área ocupada pelas gaiolas. As variáveis observadas foram: mortalidade de adultos 24 horas após a liberação, número de ovos, viabilidade da fase de ovo, período de incubação, número de ninfas e dispersão. Em folíolos com exsudato, LA716, LA1739 e PI134417 provocaram as maiores mortalidades. Adultos mortos nos folíolos desses genótipos ficaram aderidos aos tricomas glandulares, o que provocou redução na oviposição do inseto. Para dispersão, nos folíolos com exsudato, os máximos valores ocorreram nos genótipos LA716, LA462 e P25. Na condição sem exsudato, LA716 promoveu a menor dispersão das ninfas. A presença do exsudato influencia negativamente a sobrevivência e oviposição do inseto. A dispersão das ninfas também é afetada pelo exsudato, embora outros fatores possam ser importantes para o deslocamento do inseto.Several methods have been employed for evaluating plant resistance to whiteflies. Although, a few researches have been conducted aiming to determine the whitefly nymphal dispersion on crops. The objective of this work was to evaluate the oviposition of B. tabaci biotype B and nymphal dispersion in leaflets with and without
Discovering Patterns in Mathematics and Poetry
Birken, Marcia
2008-01-01
You are invited to join a fascinating journey of discovery, as Marcia Birken and Anne C. Coon explore the intersecting patterns of mathematics and poetry — bringing the two fields together in a new way.Setting the tone with humor and illustrating each chapter with countless examples, Birken and Coon begin with patterns we can see, hear, and feel and then move to more complex patterns. Number systems and nursery rhymes lead to the Golden Mean and sestinas. Simple patterns of shape introduce tessellations and concrete poetry. Fractal geometry makes fractal poetry possible. Ultimately, patterns f
Chow, Andrew; Dunlap, Christopher A; Jackson, Mark A; Flores, Daniel; Patt, Joseph M; Sétamou, Mamoudou
2016-10-01
Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata, if both natural enemies are simultaneously deployed for biological control of D. citri However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
18 CFR 701.5 - Organization pattern.
2010-04-01
... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Organization pattern... ORGANIZATION Introduction § 701.5 Organization pattern. (a) The Office of the Water Resources Council is... Council Staff headed by a Director, and Field Organizations within its jurisdiction. (b) The Water...
Directory of Open Access Journals (Sweden)
Sirigineedi Sasibhushan
2013-02-01
Full Text Available Investigation of differential expression of diapause related genes (five metabolic, five heat shock protein and one translational regulatory in HCl-treated (non-diapause and untreated (diapause eggs of B. mori during early embryogenesis (up to 48h following oviposition revealed the up-regulation of sorbitol dehydrogenase upon HCl treatment, indicating increased glycogen synthesis for further embryonic development but, down-regulation of phosphofructo kinase gene expression after 18h of oviposition indicating an arrest of glycerol and sorbitol conversion. The expression of poly A binding protein gene expression was higher upon HCl treatment, revealing the initiation of translation. The expression levels of other genes analyzed did not vary significantly, except for Hsp90 and Hsp40, which were up-regulated on acid treatment until 18h. Thus, Sorbitoldehydrogenase and phosphofructo kinasegenes have a crucial role in diapause termination as evidenced by HCl treatment, while the other genes did not have major roles.
Effects of experimental canopy manipulation on amphibian egg deposition
Zachary I. Felix; Yong Wang; Callie J. Schweitzer
2010-01-01
Although effects of forest management on amphibians are relatively well studied, few studies have examined how these practices affect egg deposition by adults, which can impact population recruitment. We quantified the effects of 4 canopy tree-retention treatments on amphibian oviposition patterns in clusters of 60-L aquatic mesocosms located in each treatment. We also...
Pandimensional field pattern changes in healers and healees: experiencing therapeutic touch.
Smith, Dorothy Woods; Broida, John P
2007-12-01
Rogers's Science of Unitary Human Beings framed this study of pandimensional pattern changes in healers and healees paired for an 8-week series of Therapeutic Touch (TT) sessions. Comparison of healee patterns before and after 141 TT sessions supported the hypotheses that healees would manifest decreased pulse and blood pressure, and reduced pain and stress (p < .05). Duration of TT sessions was not preset but determined by healers according to energy cues. TT time was not related to pattern changes, consistent with the clinical practice of TT and the atemporal nature of Rogers's conceptual framework. Healers and healees showed parallel changes after the TT series. Participants manifested greater spirituality (p <.05). Although increases in three of the four dimensions of power were significant (p <.05), changes in power measured as a whole were not. Contrary to expectations, manifestations of diversity were decreased in healers and healees.
Lau, Sai Ming; Chua, Tock H; Sulaiman, Wan-Yussof; Joanne, Sylvia; Lim, Yvonne Ai-Lian; Sekaran, Shamala Devi; Chinna, Karuthan; Venugopalan, Balan; Vythilingam, Indra
2017-03-21
Dengue remains a serious public health problem in Southeast Asia and has increased 37-fold in Malaysia compared to decades ago. New strategies are urgently needed for early detection and control of dengue epidemics. We conducted a two year study in a high human density dengue-endemic urban area in Selangor, where Gravid Ovipositing Sticky (GOS) traps were set up to capture adult Aedes spp. mosquitoes. All Aedes mosquitoes were tested using the NS1 dengue antigen test kit. All dengue cases from the study site notified to the State Health Department were recorded. Weekly microclimatic temperature, relative humidity (RH) and rainfall were monitored. Aedes aegypti was the predominant mosquito (95.6%) caught in GOS traps and 23% (43/187 pools of 5 mosquitoes each) were found to be positive for dengue using the NS1 antigen kit. Confirmed cases of dengue were observed with a lag of one week after positive Ae. aegypti were detected. Aedes aegypti density as analysed by distributed lag non-linear models, will increase lag of 2-3 weeks for temperature increase from 28 to 30 °C; and lag of three weeks for increased rainfall. Proactive strategy is needed for dengue vector surveillance programme. One method would be to use the GOS trap which is simple to setup, cost effective (below USD 1 per trap) and environmental friendly (i.e. use recyclable plastic materials) to capture Ae. aegypti followed by a rapid method of detecting of dengue virus using the NS1 dengue antigen kit. Control measures should be initiated when positive mosquitoes are detected.
Buddidathi, Radhika; Mohapatra, Soudamini; Siddamallaiah, Lekha; Manikrao, Gourishankar; Hebbar, Shibara Shankara
2016-01-01
This investigation was undertaken to compare the dissipation pattern of flubendiamide in capsicum fruits under poly-house and open field after giving spray applications at the recommended and double doses of 48 g a.i. ha(-1) and 96 g a.i. ha(-1). Extraction and purification of capsicum fruit samples were carried out by the QuEChERS method. Residues of flubendiamide and its metabolite, des-iodo flubendiamide, were analyzed by high-performance liquid chromatography-photodiode array, and confirmed by liquid chromatography-mass spectrometry/mass spectrometry. Limit of quantification of the method was 0.05 mg kg(-1), and recovery of the insecticides was in the range of 89.6-104.3%, with relative standard deviation being 4.5-11.5%. The measurement uncertainty of the analytical method was in the range of 10.7-15.7%. Initial residue deposits of flubendiamide on capsicum fruits grown under poly-house conditions were (0.977 and 1.834 mg kg(-1)) higher than that grown in the field (0.665 and 1.545 mg kg(-1)). Flubendiamide residues persisted for 15 days in field-grown and for 25 days in poly-house-grown capsicum fruits. The residues were degraded with the half-lives of 4.3-4.7 and 5.6-6.6 days in field and poly-house respectively. Des-iodo flubendiamide was not detected in capsicum fruits or soil. The residues of flubendiamide degraded to below the maximum residue limit notified by Codex Alimentarius Commission (FAO/WHO) after 1 and 6 days in open field, and 3 and 10 days in poly-house. The results of the study indicated that flubendiamide applied to capsicum under controlled environmental conditions required longer pre-harvest interval to allow its residues to dissipate to the safe level.
Wertheim, B.; Dicke, M.; Vet, L.E.M.
2002-01-01
We explored behavioural plasticity in the use of aggregation pheromone in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). Based on previous field observations, we formulated two hypotheses on a benefit of using aggregation pheromone for aggregated oviposition. One hypothesis
Wertheim, B; Dicke, Marcel; Vet, LEM
We explored behavioural plasticity in the use of aggregation pheromone in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). Based on previous field observations, we formulated two hypotheses on a benefit of using aggregation pheromone for aggregated oviposition. One hypothesis
2003-IJBCS-Article-Amadou Bocar Bal
African Journals Online (AJOL)
hp
Plots were field enclosures of 20 m2 (5 x 4 m) containing millet plants to feed nymphs. .... in order to minimize predation by birds. ..... these droplets are acceptable for insects of large size .... Changing Oviposition preferences of the desert.
Windowed fringe pattern analyis
Kemao, Qian
2013-01-01
This book provides solutions to the challenges involved in fringe pattern analysis, covering techniques for full-field, noncontact, and high-sensitivity measurement. The primary goal of fringe pattern analysis is to extract the hidden phase distributions that generally relate to the physical quantities being measured. Both theoretical analysis and algorithm development are covered to facilitate the work of researchers and engineers. The information presented is also appropriate as a specialized subject for students of optical and computer engineering.
Alves, Tavvs M; Maia, Aline H N; Barrigossi, José A F
2016-12-01
The rice stem stink bug, Tibraca limbativentris Stål (Hemiptera: Pentatomidae), is a primary insect pest of paddy rice in South America. Knowledge of its spatial distribution can support sampling plans needed for timely decisions about pest control. This study aimed to investigate the spatial distribution of adults and nymphs of T. limbativentris and determine the spatial coexistence of these stages of development. Fifteen paddy rice fields were scouted once each season to estimate insect densities. Scouting was performed on regular grids with sampling points separated by ∼50 m. Moran's I and semivariograms were used to determine spatial distribution patterns. Spatial coexistence of nymphs and adults was explored via spatial point process. Here, adults and nymphs had typically contrasting spatial distribution patterns within the same field; however, the frequency of aggregation was not different between these developmental stages. Adults and nymphs were aggregated in seven fields and randomly distributed in the other eight fields. Uniform distribution of adults or nymphs was not observed. The study-wide semivariogram ranges were ∼40 m for adults and ∼55 m for nymphs. Nymphs and adults spatially coexisted on 67% of the fields. Coexisting patterns were classified using one of the following processes: stage-independent, bidirectional attractive, unidirectional attractive, bidirectional inhibiting, or unidirectional inhibiting. The information presented herein can be important for developing sampling plans for decision-making, implementing tactics for site-specific management, and monitoring areas free of T. limbativentrisResumoO percevejo-do-colmo Tibraca limbativentris Stål (Hemiptera: Pentatomidae) é uma praga primária na cultura do arroz irrigado na América do Sul. O conhecimento de sua distribuição espacial é essencial para desenvolver planos de amostragem e para o controle desta praga. Nosso objetivo foi investigar a distribuição espacial de
DOOCS patterns, reusable software components for FPGA based RF GUN field controller
Energy Technology Data Exchange (ETDEWEB)
Pucyk, P. [Institute of Electronic Systems, Warsaw (Poland)
2006-07-01
Modern accelerator technology combines software and hardware solutions to provide distributed, high efficiency digital systems for High Energy Physics experiments. Providing flexible, maintainable software is crucial for ensuring high availability of the whole system. In order to fulfil all these requirements, appropriate design and development techniques have to be used. Software patterns are well known solution for common programming issues, providing proven development paradigms, which can help to avoid many design issues. DOOCS patterns introduces new concepts of reusable software components for control system algorithms development and implementation in DOOCS framework. Chosen patterns have been described and usage examples have been presented in this paper. (orig.)
DOOCS patterns, reusable software components for FPGA based RF GUN field controller
International Nuclear Information System (INIS)
Pucyk, P.
2006-01-01
Modern accelerator technology combines software and hardware solutions to provide distributed, high efficiency digital systems for High Energy Physics experiments. Providing flexible, maintainable software is crucial for ensuring high availability of the whole system. In order to fulfil all these requirements, appropriate design and development techniques have to be used. Software patterns are well known solution for common programming issues, providing proven development paradigms, which can help to avoid many design issues. DOOCS patterns introduces new concepts of reusable software components for control system algorithms development and implementation in DOOCS framework. Chosen patterns have been described and usage examples have been presented in this paper. (orig.)
Directory of Open Access Journals (Sweden)
Fernando L. Mantelatto
Full Text Available Abstract The aim of this study was to characterize the pattern of gastropod shell occupation in the field and selection of shell size and type under laboratory conditions by the hermit crab Pagurus criniticornis (Dana, 1852, inhabiting the infralittoral area of Anchieta Island, São Paulo, Brazil. Hermit crabs were obtained monthly during 1999 by SCUBA diving. For experiments under laboratory conditions, samplings were performed in 2002. The hermit crabs occupied 16 species of gastropods shells. Cerithium atratum (Born, 1778 was the most occupied shell (89.31%, followed by Morula nodulosa (4.73% (Adams, 1845. No difference was observed in the pattern of occupation between males and females. The equations that best demonstrated the relationship between hermit crabs and their shells were those that involved Shell Wet Weight (SWW and Shell Internal Volume (SIV. The laboratory experiments were in accordance to the pattern of occupation observed in the field; the mean value of SAI (Shell Adequacy Index recorded to the population studied was 1.13 with a trend to increase this value in the last size classes. The results obtained corroborate with the hypothesis of the occupation process of shells governed not only by availability of shells, but also by its architecture. In addition, the shell stock in the area is one another important condition related to the exhibited pattern of shell occupation by P. criniticornis, and allows the stable coexistence among the island assemblage. The pattern of occupation observed promotes a high reproductive profile for the population studied, maximizing the populational growth.
Ritchie, S A; Addison, D S; van Essen, F
1992-03-01
The distribution of Aedes taeniorhynchus eggshells in Florida mangrove basin forests was determined and used to design a sampling plan. Eggshells were found in 10/11 sites (91%), with a mean +/- SE density of 1.45 +/- 0.75/cc; density did not change significantly year to year. Highest densities were located on the sloping banks of hummocks, ponds and potholes. Eggshells were less clumped in distribution than eggs and larvae and thus required a smaller sample size for a given precision level. While eggshells were flushed from compact soil that was subject to runoff during heavy rain, mangrove peat, the dominant soil of eggshell-bearing sites, was less dense and had little runoff or eggshell flushing. We suggest that eggshell surveys could be used to identify Ae. taeniorhynchus oviposition sites and oviposition patterns.
Vaidya, Manushka
Although 1.5 and 3 Tesla (T) magnetic resonance (MR) systems remain the clinical standard, the number of 7 T MR systems has increased over the past decade because of the promise of higher signal-to-noise ratio (SNR), which can translate to images with higher resolution, improved image quality and faster acquisition times. However, there are a number of technical challenges that have prevented exploiting the full potential of ultra-high field (≥ 7 T) MR imaging (MRI), such as the inhomogeneous distribution of the radiofrequency (RF) electromagnetic field and specific energy absorption rate (SAR), which can compromise image quality and patient safety. To better understand the origin of these issues, we first investigated the dependence of the spatial distribution of the magnetic field associated with a surface RF coil on the operating frequency and electrical properties of the sample. Our results demonstrated that the asymmetries between the transmit (B1+) and receive (B 1-) circularly polarized components of the magnetic field, which are in part responsible for RF inhomogeneity, depend on the electric conductivity of the sample. On the other hand, when sample conductivity is low, a high relative permittivity can result in an inhomogeneous RF field distribution, due to significant constructive and destructive interference patterns between forward and reflected propagating magnetic field within the sample. We then investigated the use of high permittivity materials (HPMs) as a method to alter the field distribution and improve transmit and receive coil performance in MRI. We showed that HPM placed at a distance from an RF loop coil can passively shape the field within the sample. Our results showed improvement in transmit and receive sensitivity overlap, extension of coil field-of-view, and enhancement in transmit/receive efficiency. We demonstrated the utility of this concept by employing HPM to improve performance of an existing commercial head coil for the
Vaudour, E.; Leclercq, L.; Gilliot, J. M.; Chaignon, B.
2017-06-01
For any wine estate, there is a need to demarcate homogeneous within-vineyard zones ('terroirs') so as to manage grape production, which depends on vine biological condition. Until now, the studies performing digital zoning of terroirs have relied on recent spatial data and scant attention has been paid to ancient geoinformation likely to retrace past biological condition of vines and especially occurrence of vine mortality. Is vine mortality characterized by recurrent and specific patterns and if so, are these patterns related to terroir units and/or past landuse? This study aimed at performing a historical and spatial tracing of vine mortality patterns using a long time-series of aerial survey images (1947-2010), in combination with recent data: soil apparent electrical conductivity EM38 measurements, very high resolution Pléiades satellite images, and a detailed field survey. Within a 6 ha-estate in the Southern Rhone Valley, landuse and planting history were retraced and the map of missing vines frequency was constructed from the whole time series including a 2015-Pléiades panchromatic band. Within-field terroir units were obtained from a support vector machine classifier computed on the spectral bands and NDVI of Pléiades images, EM38 data and morphometric data. Repeated spatial patterns of missing vines were highlighted throughout several plantings, uprootings, and vine replacements, and appeared to match some within-field terroir units, being explained by their specific soil characteristics, vine/soil management choices and the past landuse of the 1940s. Missing vines frequency was spatially correlated with topsoil CaCO3 content, and negatively correlated with topsoil iron, clay, total N, organic C contents and NDVI. A retrospective spatio-temporal assessment of terroir therefore brings a renewed focus on some key parameters for maintaining a sustainable grape production.
Pattern formation of a nonlocal, anisotropic interaction model
Burger, Martin
2017-11-24
We consider a class of interacting particle models with anisotropic, repulsive–attractive interaction forces whose orientations depend on an underlying tensor field. An example of this class of models is the so-called Kücken–Champod model describing the formation of fingerprint patterns. This class of models can be regarded as a generalization of a gradient flow of a nonlocal interaction potential which has a local repulsion and a long-range attraction structure. In contrast to isotropic interaction models the anisotropic forces in our class of models cannot be derived from a potential. The underlying tensor field introduces an anisotropy leading to complex patterns which do not occur in isotropic models. This anisotropy is characterized by one parameter in the model. We study the variation of this parameter, describing the transition between the isotropic and the anisotropic model, analytically and numerically. We analyze the equilibria of the corresponding mean-field partial differential equation and investigate pattern formation numerically in two dimensions by studying the dependence of the parameters in the model on the resulting patterns.
Pattern formation of a nonlocal, anisotropic interaction model
Burger, Martin; Dü ring, Bertram; Kreusser, Lisa Maria; Markowich, Peter A.; Schö nlieb, Carola-Bibiane
2017-01-01
We consider a class of interacting particle models with anisotropic, repulsive–attractive interaction forces whose orientations depend on an underlying tensor field. An example of this class of models is the so-called Kücken–Champod model describing the formation of fingerprint patterns. This class of models can be regarded as a generalization of a gradient flow of a nonlocal interaction potential which has a local repulsion and a long-range attraction structure. In contrast to isotropic interaction models the anisotropic forces in our class of models cannot be derived from a potential. The underlying tensor field introduces an anisotropy leading to complex patterns which do not occur in isotropic models. This anisotropy is characterized by one parameter in the model. We study the variation of this parameter, describing the transition between the isotropic and the anisotropic model, analytically and numerically. We analyze the equilibria of the corresponding mean-field partial differential equation and investigate pattern formation numerically in two dimensions by studying the dependence of the parameters in the model on the resulting patterns.
Identification system by eye retinal pattern
International Nuclear Information System (INIS)
Sunagawa, Takahisa; Shibata, Susumu
1987-01-01
Identification system by eye retinal pattern is introduced from the view-point of history of R and D, measurement, apparatus, evaluation tests, safety and application. According to our evaluation tests, enrolling time is approximately less than 1 min, verification time is a few seconds and false accept rate is 0 %. Evaluation tests at Sandia National Laboratories in USA show the comparison data of false accept rates such as 0 % for eye retinal pattern, 10.5 % for finger-print, 5.8 % for signature dynamics and 17.7 % for speaker voice. The identification system by eye retinal pattern has only three applications in Japan, but there has been a number of experience in USA. This fact suggests that the system will become an important means for physical protections not only in nuclear field but also in other industrial fields in Japan. (author)
Distributional patterns of fall armyworm parasitoids in a corn field and pasture field in Florida
An assessment of parasitoids and their selective patterns among Spodoptera frugiperda corn and rice host strains was performed from August 2008-August 2010 in a corn crop and a grass pasture in northern Florida under different seasonal conditions (spring and fall). Sentinel larvae from our laborator...
Rapid change of field line connectivity and reconnection in stochastic magnetic fields
International Nuclear Information System (INIS)
Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.
2014-01-01
Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.
International Nuclear Information System (INIS)
Saour, G.
2009-01-01
Laboratory experiments with Trichogramma principium Sugonyaev and Sorokina females offered potato tuber moth Phthorimaea operculella (Zeller) eggs demonstrated that wasps rates of oviposition were highest the first day and decreased gradually thereafter. In addition, when T. principium females were sequentially offered eggs from 250-Gy irradiated parents or obtained from non-irradiated moths, the probability of host acceptance was not influenced by treatment of host eggs. In a concurrent laboratory study, a large cage test with combinant releases of T. principium and 250-Gy irradiated moths produced the greatest reduction in potato tuber moth F3-emerged progeny. Reductions obtained with irradiated moths alone, single release of irradiated moths with T. principium, and one or three releases of parasitoids were significantly higher than those in the control. From a pest management perspective, T. principium releases would synergistically complement the effects of F1 sterility against potato tuber moth infestation. (author)
Sierra-Pérez, Julián; Torres-Arredondo, M.-A.; Alvarez-Montoya, Joham
2018-01-01
Structural health monitoring consists of using sensors integrated within structures together with algorithms to perform load monitoring, damage detection, damage location, damage size and severity, and prognosis. One possibility is to use strain sensors to infer structural integrity by comparing patterns in the strain field between the pristine and damaged conditions. In previous works, the authors have demonstrated that it is possible to detect small defects based on strain field pattern recognition by using robust machine learning techniques. They have focused on methodologies based on principal component analysis (PCA) and on the development of several unfolding and standardization techniques, which allow dealing with multiple load conditions. However, before a real implementation of this approach in engineering structures, changes in the strain field due to conditions different from damage occurrence need to be isolated. Since load conditions may vary in most engineering structures and promote significant changes in the strain field, it is necessary to implement novel techniques for uncoupling such changes from those produced by damage occurrence. A damage detection methodology based on optimal baseline selection (OBS) by means of clustering techniques is presented. The methodology includes the use of hierarchical nonlinear PCA as a nonlinear modeling technique in conjunction with Q and nonlinear-T 2 damage indices. The methodology is experimentally validated using strain measurements obtained by 32 fiber Bragg grating sensors bonded to an aluminum beam under dynamic bending loads and simultaneously submitted to variations in its pitch angle. The results demonstrated the capability of the methodology for clustering data according to 13 different load conditions (pitch angles), performing the OBS and detecting six different damages induced in a cumulative way. The proposed methodology showed a true positive rate of 100% and a false positive rate of 1.28% for a
Niche separation of pollen beetle parasitoids
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Josef eBerger
2015-05-01
Full Text Available Species with similar resource requirements are commonly assumed to competitively exclude each other, unless they differentiate their ecological niches. Hence, parasitoid wasps that use the same host species need to find some way to avoid competition. The aim of this study was to identify the role of volatile cues from oilseed rape plants and the larval host in niche separation between three coexisting parasitoid species. We examined how Phradis interstitialis, Phradis morionellus and Tersilochus heterocerus, sympatric parasitoids of Brassicogethes aeneus, differ in their abundances, distribution on buds and flowers, and oviposition behavior in the field. Furthermore, we tested their preferences for odours from uninfested and infested oilseed rape plants in the bud and flowering stage, and their preferences for odours from three developmental stages of pollen beetle larvae in a two-choice olfactometer bioassay.P. interstitialis was active in the field early in the season, preferred odours of infested buds versus uninfested, and oviposited into buds which contained only pollen beetle eggs, while P. morionellus was active late in the season, preferred odours of infested buds as well as odours of infested flowers over uninfested, and oviposited into buds which contained only larvae. T. heterocerus was active throughout the season, and preferred odours of infested flowers over uninfested. Neither Phradis species were attracted to larval odours, whereas T. heterocerus was attracted to odours from first-instar pollen beetle larvae both in the absence of plant odours, and when presented simultaneously with uninfested plant odour.This suggests that the two Phradis species are separated on a temporal scale and that they parasitize different host stages, while the larval parasitoids P. morionellus and T. heterocerus are separated by choice of microhabitat. The former oviposits into larvae in buds, and the latter in flowers.
Three-dimensional phase-field simulations of directional solidification
Plapp, Mathis
2007-05-01
The phase-field method has become the method of choice for simulating microstructural pattern formation during solidification. One of its main advantages is that time-dependent three-dimensional simulations become feasible, which makes it possible to address long-standing questions of pattern stability and pattern selection. Here, a brief introduction to the phase-field model and its implementation is given, and its capabilities are illustrated by examples taken from the directional solidification of binary alloys. In particular, the morphological stability of hexagonal cellular arrays and of eutectic lamellar patterns is investigated.
Effect of critical field on screened dielectric breakdown growth
International Nuclear Information System (INIS)
Wang Wei.
1993-10-01
In this paper we have shown that due to a critical field, the patterns growing in the screened Laplacian field will be affected. When the critical field is zero, there is a transition from a dense growing to single branch of aggregate. At a higher critical field, the pattern shows a spiky-type aggregate, and for a small critical field the transition is cut. For an intermediate critical field, the result shows that below the transition, there no dense structure. (author). 9 refs, 2 figs
Seasonal dependence of high-latitude electric fields
International Nuclear Information System (INIS)
de la Beaujardiere, O.; Leger, C.; Alcayde, D.; Fontanari, J.
1991-01-01
The seasonal dependence of the high-latitude electric field was investigated using Sondrestrom incoherent scatter radar data. Average ExB drifts were derived from 5 years of measurements centered around solar minimum. The electrostatic potentials that best fit the observed average electric field were calculated. It was found that the large-scale convection pattern significantly changes with season. This change involves the overall shape of the convection pattern, as well as the electric field intensity, and thus the total dawn-dusk potential across the polar cap. The cross polar cap potential drop is largest in fall, followed by winter, spring and summer. The small difference found between the summer and winter cross polar cap potential can be attributed to differing field-aligned potential drops. In view of the well-known relationship between field-aligned currents and parallel potential drop, this is consistent with the observations that Birkeland currents are larger in the summer than in winter. Changes in the overall shape of the convection pattern are consistent with the simple notion that the whole pattern is shifted toward the nightside as well as, to a lesser extent, toward the dawnside in summer as compared to winter. This assumption is based on the following observed effects: (1) The rotation of the overall convection pattern toward earlier local times with respect to the noon-midnight direction is maximum for summer on the dayside. (2) On the nightside, the Harang discontinuity is typically located within the radar field of view (Λ=67 to 82) in the winter averaged patterns, but it is equatorward of the field of view in summer. (3) The line that joins the dawn and dusk potential maxima is shifted toward the midnight sector in summer as compared to winter by about 5 degree. (4) In the dawn cell, the latitude of the convection reversal is the lowest during summer; in the dusk cell the latitude of the reversal is the lowest during winter
Different injury pattern in goalkeepers compared to field players
DEFF Research Database (Denmark)
Eirale, Cristiano; Tol, Johannes L; Whiteley, Rod
2014-01-01
Goalkeepers have a specific physiological and biomechanical profile including hip loading with increased frontal plane kinetics and explosive side jumps. The aim of this study is to analyze the injury incidence in professional goalkeepers and to compare this with field players.......Goalkeepers have a specific physiological and biomechanical profile including hip loading with increased frontal plane kinetics and explosive side jumps. The aim of this study is to analyze the injury incidence in professional goalkeepers and to compare this with field players....
Assay of old-world screw-worm fly, Chrysomya bezziana, labelled with 32P
International Nuclear Information System (INIS)
Lamb, K.P.; Sands, D.P.A.; Spradbery, J.P.
1978-01-01
Techniques for 32 P labelling of larvae and adults of the screw-worm fly, Chrysomya bezziana, are described. Egg masses of labelled flies were readily identified. At the doses used for field releases, oviposition activity, fertility and longevity of female flies were not adversely affected. Radioactive egg masses were recovered from sentinel animals following field release of labelled flies. (Auth.)
Ikehata, Masateru; Iwasaka, Masakazu; Miyakoshi, Junji; Ueno, Shoogo; Koana, Takao
2003-05-01
Effects of magnetic fields (MFs) on biological systems are usually investigated using biological indices such as gene expression profiles. However, to precisely evaluate the biological effects of MF, the effects of intense MFs on systematic material transport processes including experimental environment must be seriously taken into consideration. In this study, a culture of the budding yeast, Saccharomyces cerevisiae, was used as a model for an in vitro biological test system. After exposure to 5 T static vertical MF, we found a difference in the sedimentation pattern of cells depending on the location of the dish in the magnet bore. Sedimented cells were localized in the center of the dish when they were placed in the lower part of the magnet bore while the sedimentation of the cells was uniform in dishes placed in the upper part of the bore because of the diamagnetic force. Genome wide gene expression profile of the yeast cells after exposure to 5 T static MF for 2 h suggested that the MF did not affect the expression level of any gene in yeast cells although the sedimentation pattern was altered. In addition, exposure to 10 T for 1 h and 5 T for 24 h also did not affect the gene expression. On the other hand, a slight change in expressions of several genes which are related to respiration was observed by exposure to a 14 T static MF for 24 h. The necessity of estimating the indirect effects of MFs on a study of its biological effect of MF in vitro will be discussed.
Stuhl, Charles; Sivinski, John; Teal, Peter; Paranhos, Beatriz; Aluja, Martin
2011-06-01
Tephritid fruit fly parasitoids use fruit-derived chemical cues and the vibrations that result from larval movements to locate hosts sequestered inside fruit. However, compounds produced by the larvae themselves have not been previously described nor their significance to parasitoid foraging determined. We collected the volatiles from four species of tropical and subtropical Tephritidae: Anastrepha suspensa (Loew), Bactrocera dorsalis Hendel, Bactrocera cucurbitae Coquillett, and Ceratitis capitata (Wiedemann), representing two subfamilies (Dacinae and Trypetinae). Para-ethylacetophenone, an analog of a known tephritid parasitoid attractant, was a major constituent of all four, and was not associated with larvae of another acalypterate fly, Drosophila melanogaster Meigen, or with the calypterate Musca domestica L. It also was present in volatiles from whole, A. suspensa infested fruits of Eugenia uniflora (L.). Para-ethylacetophenone was not necessarily produced as a direct consequence of fruit consumption because it also was detected from larvae that developed in two artificial diets and in spent diets subsequent to larval development. Sensillae on both the antennae and ovipositor of the opiine braconid fruit fly parasitoid, Diachasmimorpha longicaudata (Ashmead) responded to the para-ethylacetophenone in larval volatiles and as a synthetic. Although a potential cue to foraging parasitoids, para-ethylacetophenone showed no long range (>1m) attractiveness to the adult female parasitoid, but did stimulate ovipositor-insertion and oviposition into both a natural (fruit) and an artificial (parafilm) substrate. Thus it may prove useful in colonizing and mass-rearing opine fruit fly parasitoids.
International Nuclear Information System (INIS)
Papitashvili, V.O.; Belov, B.A.; Gromova, L.I.
1989-01-01
Equivalent ionospheric current patterns are derived from ground-based geomagnetic observations for events on 11-12 November 1979 (B/sub z/ >> 0), 24 November 1981 (B/sub z/ > 0) (B/sub y/ >> 0), and 25-26 November 1979 (B/sub y/ 0 . Due to stable external conditions, it is possible to calculate the field-aligned current (FAC) density within cells formed by two adjacent stations by taking into account the uniform conductivity of the summer polar ionosphere. These results completely correspond to regressional analysis of interplanetary magnetic fields (IMF) and ground-based geomagnetic data, and also to satellite observations of the NBZ current system. During stable southward IMF a new result was obtained, a reversal of antisunward convection flow is identified, and an NBZ-like FAC system is restored in the central part of the southern polar cap. The authors conclude that there may be an additional NBZ-like FAC system poleward of -85 0 , which is independent of the IMF and is generated by the quasi-viscous interaction between solar-wind plasma and high-latitude lobes of the magnetospheric tail
Acoustic Pattern Recognition on Android Devices
DEFF Research Database (Denmark)
Møller, Maiken Bjerg; Gaarsdal, Jesper; Steen, Kim Arild
2013-01-01
an Android application developed for acoustic pattern recognition of bird species. The acoustic data is recorded using a built-in microphone, and pattern recognition is performed on the device, requiring no network connection. The algorithm is implemented in C++ as a native Android module and the Open......CV library is used for signal processing. We conclude that the approach presented here is a viable solution to pattern recognition problems. Since it requires no network connection, it shows promise in fields such as wildlife research....
Colony strength and queen replacement in Melipona marginata (Apidae: Meliponini
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A. de M. P. Kleinert
Full Text Available Physogastric queens of Melipona marginata were removed from their colonies in order to verify the acceptance of a new queen by workers. Colony strength was evaluated according to queen oviposition rate and comb diameters. Replacement was observed seven times. Its occurrence and speed related positively to colony strength, independently of queen's age. In weak colonies, queen replacement was observed only once, following colony population increase that occurred after introduction of combs from another colony. Worker oviposition after queen removal was observed three times: in a strong colony with virgin queens and males, and in two of the weak colonies. In the first two or three days of new queen oviposition, during which most of the eggs were eaten by the queen, worker oviposition preceded almost all provisioning and oviposition processes (POPs. After this period, worker oviposition decreased until it reached around 25% of the POPs. Daily oviposition rate of young queens decreased or was even interrupted by hatching of their first brood.
A unidirectional subwavelength focusing near-field plate
Energy Technology Data Exchange (ETDEWEB)
Imani, Mohammadreza F.; Grbic, Anthony [Radiation Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2014-01-28
Near-field plates consist of non-periodically patterned surfaces that can overcome the diffraction limit and confine electromagnetic fields to subwavelength dimensions. Previous near-field plates experimentally demonstrated extreme field tailoring capabilities. However, their performance suffered from radiation/reflection in undesired directions, those other than the subwavelength focus. This issue can limit the practical use of near-field plates. In this paper, we address this issue by designing a unidirectional near-field plate that can form a subwavelength focal pattern, while suppressing the field radiated/reflected in other directions. The design and operation of the proposed unidirectional near-field plate are verified through full-wave simulation. The unidirectional near-field plate may find application in high resolution imaging and probing, high density data storage, and wireless power transfer systems. As an example, its utility as a high resolution probe is demonstrated through full-wave electromagnetic simulation.
Designing Interactions in Tourism Mediascape: Identification of Patterns for Mobile 2.0 Platform
DEFF Research Database (Denmark)
Tussyadiah, Iis; Fesenmaier, Daniel R.; Yoo, Youngjin
2008-01-01
This study uses pattern language theory in order to identify patterns of tourists’ interactions within their social networks while they are experiencing tourism destinations. The patterns were conceptualized from sequences of tourists’ stories and observers’ field notes through narrative analysis....... The identified patterns were then organized into a typical scenario of tourism experiences. The Mobile 2.0 platform is then characterized as an interactive mediascape that mediates tourists in situ.......This study uses pattern language theory in order to identify patterns of tourists’ interactions within their social networks while they are experiencing tourism destinations. The patterns were conceptualized from sequences of tourists’ stories and observers’ field notes through narrative analysis...
Natural course of visual field loss in patients with Type 2 Usher syndrome.
Fishman, Gerald A; Bozbeyoglu, Simge; Massof, Robert W; Kimberling, William
2007-06-01
To evaluate the natural course of visual field loss in patients with Type 2 Usher syndrome and different patterns of visual field loss. Fifty-eight patients with Type 2 Usher syndrome who had at least three visual field measurements during a period of at least 3 years were studied. Kinetic visual fields measured on a standard calibrated Goldmann perimeter with II4e and V4e targets were analyzed. The visual field areas in both eyes were determined by planimetry with the use of a digitalizing tablet and computer software and expressed in square inches. The data for each visual field area measurement were transformed to a natural log unit. Using a mixed model regression analysis, values for the half-life of field loss (time during which half of the remaining field area is lost) were estimated. Three different patterns of visual field loss were identified, and the half-life time for each pattern of loss was calculated. Of the 58 patients, 11 were classified as having pattern type I, 12 with pattern type II, and 14 with pattern type III. Of 21 patients whose visual field loss was so advanced that they could not be classified, 15 showed only a small residual central field (Group A) and 6 showed a residual central field with a peripheral island (Group B). The average half-life times varied between 3.85 and 7.37 for the II4e test target and 4.59 to 6.42 for the V4e target. There was no statistically significant difference in the half-life times between the various patterns of field loss or for the test targets. The average half-life times for visual field loss in patients with Usher syndrome Type 2 were statistically similar among those patients with different patterns of visual field loss. These findings will be useful for counseling patients with Type 2 Usher syndrome as to their prognosis for anticipated visual field loss.
Analysis of multi-species point patterns using multivariate log Gaussian Cox processes
DEFF Research Database (Denmark)
Waagepetersen, Rasmus; Guan, Yongtao; Jalilian, Abdollah
Multivariate log Gaussian Cox processes are flexible models for multivariate point patterns. However, they have so far only been applied in bivariate cases. In this paper we move beyond the bivariate case in order to model multi-species point patterns of tree locations. In particular we address t...... of the data. The selected number of common latent fields provides an index of complexity of the multivariate covariance structure. Hierarchical clustering is used to identify groups of species with similar patterns of dependence on the common latent fields.......Multivariate log Gaussian Cox processes are flexible models for multivariate point patterns. However, they have so far only been applied in bivariate cases. In this paper we move beyond the bivariate case in order to model multi-species point patterns of tree locations. In particular we address...... the problems of identifying parsimonious models and of extracting biologically relevant information from the fitted models. The latent multivariate Gaussian field is decomposed into components given in terms of random fields common to all species and components which are species specific. This allows...
Czech Academy of Sciences Publication Activity Database
DeSimone, A.; Kružík, Martin
2013-01-01
Roč. 8, č. 2 (2013), s. 481-499 ISSN 1556-1801 R&D Projects: GA ČR(CZ) GAP201/12/0671 Institutional support: RVO:67985556 Keywords : hysteresis * shape memory Subject RIV: BA - General Mathematics Impact factor: 0.952, year: 2013 http://library.utia.cas.cz/separaty/2013/MTR/kruzik-domain patterns and hysteresis in phase-transforming solids analysis and numerical simulations of a sharp interface dissipative model via phase-field approximation.pdf
Directory of Open Access Journals (Sweden)
Quispe Vicente
2008-07-01
Full Text Available Abstract Background The length of the gonotrophic cycle varies the vectorial capacity of a mosquito vector and therefore its exact estimation is important in epidemiological modelling. Because the gonotrophic cycle length depends on temperature, its estimation can be satisfactorily computed by means of physiological time analysis. Methods A model of physiological time was developed and calibrated for Anopheles pseudopunctipennis, one of the main malaria vectors in South America, using data from laboratory temperature controlled experiments. The model was validated under varying temperatures and could predict the time elapsed from blood engorgement to oviposition according to the temperature. Results In laboratory experiments, a batch of An. pseudopunctipennis fed at the same time may lay eggs during several consecutive nights (2–3 at high temperature and > 10 at low temperature. The model took into account such pattern and was used to predict the range of the gonotrophic cycle duration of An. pseudopunctipennis in four characteristic sites of Bolivia. It showed that the predicted cycle duration for An. pseudopunctipennis exhibited a seasonal pattern, with higher variances where climatic conditions were less stable. Predicted mean values of the (minimum duration ranged from 3.3 days up to > 10 days, depending on the season and the geographical location. The analysis of ovaries development stages of field collected biting mosquitoes indicated that the phase 1 of Beklemishev might be of significant duration for An. pseudopunctipennis. The gonotrophic cycle length of An. pseudopunctipennis correlates with malaria transmission patterns observed in Bolivia which depend on locations and seasons. Conclusion A new presentation of cycle length results taking into account the number of ovipositing nights and the proportion of mosquitoes laying eggs is suggested. The present approach using physiological time analysis might serve as an outline to other
Modeling the developmental patterns of auditory evoked magnetic fields in children.
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Rupesh Kotecha
Full Text Available BACKGROUND: As magnetoencephalography (MEG is of increasing utility in the assessment of deficits and development delays in brain disorders in pediatrics, it becomes imperative to fully understand the functional development of the brain in children. METHODOLOGY: The present study was designed to characterize the developmental patterns of auditory evoked magnetic responses with respect to age and gender. Sixty children and twenty adults were studied with a 275-channel MEG system. CONCLUSIONS: Three main responses were identified at approximately 46 ms (M50, 71 ms (M70 and 106 ms (M100 in latency for children. The latencies of M70 and M100 shortened with age in both hemispheres; the latency of M50 shortened with age only in the right hemisphere. Analysis of developmental lateralization patterns in children showed that the latency of the right hemispheric evoked responses shortened faster than the corresponding left hemispheric responses. The latency of M70 in the right hemisphere highly correlated to the age of the child. The amplitudes of the M70 responses increased with age and reached their peaks in children 12-14 years of age, after which they decreased with age. The source estimates for the M50 and M70 responses indicated that they were generated in different subareas in the Heschl's gyrus in children, while not localizable in adults. Furthermore, gender also affected developmental patterns. The latency of M70 in the right hemisphere was proposed to be an index of auditory development in children, the modeling equation is 85.72-1.240xAge (yrs. Our results demonstrate that there is a clear developmental pattern in the auditory cortex and underscore the importance of M50 and M70 in the developing brain.
Pattern recognition and classification an introduction
Dougherty, Geoff
2012-01-01
The use of pattern recognition and classification is fundamental to many of the automated electronic systems in use today. However, despite the existence of a number of notable books in the field, the subject remains very challenging, especially for the beginner. Pattern Recognition and Classification presents a comprehensive introduction to the core concepts involved in automated pattern recognition. It is designed to be accessible to newcomers from varied backgrounds, but it will also be useful to researchers and professionals in image and signal processing and analysis, and in computer visi
Host plant adaptation in Drosophila mettleri populations.
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Sergio Castrezana
Full Text Available The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total. We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp. in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.
Joshi, Mark
2015-01-01
This innovative textbook introduces a new pattern-based approach to learning proof methods in the mathematical sciences. Readers will discover techniques that will enable them to learn new proofs across different areas of pure mathematics with ease. The patterns in proofs from diverse fields such as algebra, analysis, topology and number theory are explored. Specific topics examined include game theory, combinatorics, and Euclidean geometry, enabling a broad familiarity. The author, an experienced lecturer and researcher renowned for his innovative view and intuitive style, illuminates a wide range of techniques and examples from duplicating the cube to triangulating polygons to the infinitude of primes to the fundamental theorem of algebra. Intended as a companion for undergraduate students, this text is an essential addition to every aspiring mathematician’s toolkit.
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King, Gareth Edward
2016-06-01
Full Text Available Original data are presented which describe ova of the following six taxa in the Sterrhinae Meyrick, 1892: Idaea litigiosaria (Boisduval, 1840, Idaea sericeata calvaria Wehrli, 1927, Idaea ochrata albida (Zerny, 1936, Idaea incisaria (Staudinger, 1892, Idaea cervantaria (Millière, 1869 and >em>Scopula (Glossotrophia asellaria dentatolineata Wehrli, 1926. Subsequent analysis of SEM imaging provides data related to the chorion structure, as well as that associated with the strategies adopted by females at oviposition under laboratory conditions; comparative data are provided of other European sterrhines.Se presentan datos inéditos que describen los huevos de los siguientes taxones de Sterrhinae Meyrick, 1892: Idaea litigiosaria (Boisduval, 1840, Idaea sericeata calvaria Wehrli, 1927, Idaea ochrata albida (Zerny, 1936, Idaea incisaria (Staudinger, 1892, Idaea cervantaria (Millière, 1869 and Scopula (Glossotrophia asellaria dentatolineata Wehrli, 1926. Se ofrece un análisis pormenorizado de las imágenes MEB en cuanto a la estructura del corión se refiere, además de una descripción de las estrategias de la puesta adoptadas por parte de las hembras en condiciones de laboratorio. Se ofrecen datos comparativos con otras especies europeas de Sterrhinae.
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Rui-Wu Wang
2009-11-01
Full Text Available Fig trees are pollinated by fig wasps, which also oviposit in female flowers. The wasp larvae gall and eat developing seeds. Although fig trees benefit from allowing wasps to oviposit, because the wasp offspring disperse pollen, figs must prevent wasps from ovipositing in all flowers, or seed production would cease, and the mutualism would go extinct. In Ficus racemosa, we find that syconia ('figs' that have few foundresses (ovipositing wasps are underexploited in the summer (few seeds, few galls, many empty ovules and are overexploited in the winter (few seeds, many galls, few empty ovules. Conversely, syconia with many foundresses produce intermediate numbers of galls and seeds, regardless of season. We use experiments to explain these patterns, and thus, to explain how this mutualism is maintained. In the hot summer, wasps suffer short lifespans and therefore fail to oviposit in many flowers. In contrast, cooler temperatures in the winter permit longer wasp lifespans, which in turn allows most flowers to be exploited by the wasps. However, even in winter, only in syconia that happen to have few foundresses are most flowers turned into galls. In syconia with higher numbers of foundresses, interference competition reduces foundress lifespans, which reduces the proportion of flowers that are galled. We further show that syconia encourage the entry of multiple foundresses by delaying ostiole closure. Taken together, these factors allow fig trees to reduce galling in the wasp-benign winter and boost galling (and pollination in the wasp-stressing summer. Interference competition has been shown to reduce virulence in pathogenic bacteria. Our results show that interference also maintains cooperation in a classic, cooperative symbiosis, thus linking theories of virulence and mutualism. More generally, our results reveal how frequency-dependent population regulation can occur in the fig-wasp mutualism, and how a host species can 'set the rules of the
International Nuclear Information System (INIS)
Rajasooriyar, Chrishanthi; Van Dyk, Sylvia; Bernshaw, David; Kondalsamy-Chennakesavan, Srinivas; Barkati, Maroie; Narayan, Kailash
2011-01-01
Purpose: The purpose of this study was to evaluate the patterns of failure and overall survival (OS) and disease-free survival (DFS) rates in cervical cancer patients who had metastatic disease in common iliac or para-aortic lymph nodes and were treated with curative intent, using extended field radiotherapy (EFRT). Methods and Materials: This was a retrospective study involving 39 patients treated from January 1996 to June 2007, using EFRT with concurrent chemotherapy and intracavitary brachytherapy. EFRT consisted of 45 Gy in 1.8-Gy fractions. Radiation to involved nodes was boosted to a total dose of 50.4 to 54 Gy. Primary tumor radiation was boosted to a dose of 80 Gy using brachytherapy. Results: Overall, 30 patients (77%) have relapsed. The 5-year OS rate was 26% (95% confidence interval [CI], 11-44). The 5-year DFS rate was 19.4% (95% CI, 8-35). Only 3 patients (7.5%) experienced treatment failure exclusively within the treatment field, and 2 patients underwent salvage treatment. Grade 3 to 4 acute bone marrow and gastrointestinal toxicities were observed in 10 (26%) and 7 (18%) patients, respectively. Conclusions: Concurrent chemotherapy and EFRT treatment was well tolerated. Most patients showed failure at multiple sites and outside the treatment field. Only 3/39 patients had failures exclusively within the treatment field, and 2 underwent salvage treatment.
An Indirect Defence Trait Mediated through Egg-Induced Maize Volatiles from Neighbouring Plants.
Directory of Open Access Journals (Sweden)
Daniel M Mutyambai
C. sesamiae parasitic wasps indicated that these parasitoids preferred volatiles from oviposited and neighbouring landrace plants compared to those from the control plants. This effect was absent in the standard commercial hybrid we tested. There was no HIPV induction and no difference in parasitoid attraction in neighbouring and control hybrid maize plants. These results show plant-plant signalling: 'Nyamula' maize plants emitting oviposition-induced volatiles attractive to the herbivore's natural enemies can induce this indirect defence trait in conspecific neighbouring undamaged maize plants. Maize plants growing in a field may thus benefit from this indirect defence through airborne signalling which may enhance the fitness of the volatile-emitting plant by increasing predation pressure on herbivores.
Base Station Antenna Pattern Distortion in Practical Urban Deployment Scenarios
DEFF Research Database (Denmark)
Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Sørensen, Troels Bundgaard
2014-01-01
In real urban deployments, base station antennas are typically not placed in free space conditions. Therefore, the radiation pattern can be affected by mounting structures and nearby obstacles located in the proximity of the antenna (near-field), which are often not taken into consideration. Also...... presents a combination of near-field and far-field simulations aimed to provide an overview of the distortion experienced by the base station antenna pattern in two different urban deployment scenarios: rooftop and telecommunications tower. The study illustrates how, in comparison with the near...
Strauch, B.; Heeschen, K. U.; Priegnitz, M.; Abendroth, S.; Spangenberg, E.; Thaler, J.; Schicks, J. M.
2015-12-01
The GFZ's LArge Reservoir Simulator LARS allows for the simulation of the 2008 Mallik gas hydrate production test and the comparison of fluid flow patterns and their driving forces. Do we see the gas flow pattern described for Mallik [Uddin, M. et al., J. Can. Petrol Tech, 50, 70-89, 2011] in a pilot scale test? If so, what are the driving forces? LARS has a network of temperature sensors and an electric resistivity tomography (ERT) enabling a good spatial resolution of gas hydrate occurrences, water and gas distribution, and changes in temperature in the sample. A gas flow meter and a water trap record fluid flow patterns and a backpressure valve has controlled the depressurization equivalent to the three pressure stages (7.0 - 5.0 - 4.2 MPa) applied in the Mallik field test. The environmental temperature (284 K) and confining pressure (13 MPa) have been constant. The depressurization induced immediate endothermic gas hydrate dissociation until re-establishment of the stability conditions by a consequent temperature decrease. Slight gas hydrate dissociation continued at the top and upper lateral border due to the constant heat input from the environment. Here transport pathways were short and permeability higher due to lower gas hydrate saturation. At pressures of 7.0 and 5.0 MPa the LARS tests showed high water flow rates and short irregular spikes of gas production. The gas flow patterns at 4.2 MPa and 3.0MPa resembled those of the Mallik test. In LARS the initial gas surges overlap with times of hydrate instability while water content and lengths of pathways had increased. Water production was at a minimum. A rapidly formed continuous gas phase caused the initial gas surges and only after gas hydrate dissociation decreased to a minimum the single gas bubbles get trapped before slowly coalescing again. In LARS, where pathways were short and no additional water was added, a transport of microbubbles is unlikely to cause a gas surge as suggested for Mallik.
Brodusch, Nicolas; Demers, Hendrix; Gauvin, Raynald
2015-01-01
Dark-field (DF) images were acquired in the scanning electron microscope with an offline procedure based on electron backscatter diffraction (EBSD) patterns (EBSPs). These EBSD-DF images were generated by selecting a particular reflection on the electron backscatter diffraction pattern and by reporting the intensity of one or several pixels around this point at each pixel of the EBSD-DF image. Unlike previous studies, the diffraction information of the sample is the basis of the final image contrast with a pixel scale resolution at the EBSP providing DF imaging in the scanning electron microscope. The offline facility of this technique permits the selection of any diffraction condition available in the diffraction pattern and displaying the corresponding image. The high number of diffraction-based images available allows a better monitoring of deformation structures compared to electron channeling contrast imaging (ECCI) which is generally limited to a few images of the same area. This technique was applied to steel and iron specimens and showed its high capability in describing more rigorously the deformation structures around micro-hardness indents. Due to the offline relation between the reference EBSP and the EBSD-DF images, this new technique will undoubtedly greatly improve our knowledge of deformation mechanism and help to improve our understanding of the ECCI contrast mechanisms. Copyright © 2014 Elsevier B.V. All rights reserved.
Writing magnetic patterns with surface acoustic waves
Energy Technology Data Exchange (ETDEWEB)
Li, Weiyang; Buford, Benjamin; Jander, Albrecht; Dhagat, Pallavi, E-mail: dhagat@eecs.oregonstate.edu [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331 (United States)
2014-05-07
A novel patterning technique that creates magnetization patterns in a continuous magnetostrictive film with surface acoustic waves is demonstrated. Patterns of 10 μm wide stripes of alternating magnetization and a 3 μm dot of reversed magnetization are written using standing and focusing acoustic waves, respectively. The magnetization pattern is size-tunable, erasable, and rewritable by changing the magnetic field and acoustic power. This versatility, along with its solid-state implementation (no moving parts) and electronic control, renders it as a promising technique for application in magnetic recording, magnonic signal processing, magnetic particle manipulation, and spatial magneto-optical modulation.
The cell pattern correction through design-based metrology
Kim, Yonghyeon; Lee, Kweonjae; Chang, Jinman; Kim, Taeheon; Han, Daehan; Lee, Kyusun; Hong, Aeran; Kang, Jinyoung; Choi, Bumjin; Lee, Joosung; Yeom, Kyehee; Lee, Jooyoung; Hong, Hyeongsun; Lee, Kyupil; Jin, Gyoyoung
2015-03-01
Starting with the sub 2Xnm node, the process window becomes smaller and tighter than before. Pattern related error budget is required for accurate critical-dimension control of Cell layers. Therefore, lithography has been faced with its various difficulties, such as weird distribution, overlay error, patterning difficulty etc. The distribution of cell pattern and overlay management are the most important factors in DRAM field. We had been experiencing that the fatal risk is caused by the patterns located in the tail of the distribution. The overlay also induces the various defect sources and misalignment issues. Even though we knew that these elements are important, we could not classify the defect type of Cell patterns. Because there is no way to gather massive small pattern CD samples in cell unit block and to compare layout with cell patterns by the CD-SEM. The CD- SEM is used in order to gather these data through high resolution, but CD-SEM takes long time to inspect and extract data because it measures the small FOV. (Field Of View) However, the NGR(E-beam tool) provides high speed with large FOV and high resolution. Also, it's possible to measure an accurate overlay between the target layout and cell patterns because they provide DBM. (Design Based Metrology) By using massive measured data, we extract the result that it is persuasive by applying the various analysis techniques, as cell distribution and defects, the pattern overlay error correction etc. We introduce how to correct cell pattern, by using the DBM measurement, and new analysis methods.
Pattern formation during electropolishing
International Nuclear Information System (INIS)
Yuzhakov, V.V.; Chang, H.; Miller, A.E.
1997-01-01
Using atomic force microscopy, we find that the surface morphology of a dissolving aluminum anode in a commercial electropolishing electrolyte can exhibit both highly regular and randomly packed stripe and hexagonal patterns with amplitudes of about 5 nm and wavelengths of 100 nm. The driving instability of this pattern formation phenomenon is proposed to be the preferential adsorption of polar or polarizable organic molecules on surface ridges where the contorted double layer produces a higher electric potential gradient. The enhanced relative coverage shields the anode and induces a smaller dissolution rate at the ridges. The instability is balanced by surface diffusion of the adsorbate to yield a length scale of 4π(D s /k d ) 1/2 , where D s is the surface diffusivity and k d is the desorption coefficient of the adsorbate, which correlates well with the measured wavelength. A long-wavelength expansion of the double-layer field yields an interface evolution equation that reproduces all of the observed patterns. In particular, bifurcation analysis and numerical simulation yield a single voltage-dependent dimensionless parameter ξ that measures a balance between smoothing of adsorbate concentration by electric-field-dependent surface diffusion and fluctuation due to interfacial curvature and stretching. Randomly oriented stripes are favored at large ξ (low voltage), while random hills dominate at small ξ (high voltage) with perfectly periodic stripes and hexagonal hill patterns within a small window near ξ=1. These predictions are in qualitative and quantitative agreement with our measurements. copyright 1997 The American Physical Society
Visualizing Data Patterns with Micromaps
Carr, Daniel B
2010-01-01
After more than 15 years of development drawing on research in cognitive psychology, statistical graphics, computer science, and cartography, micromap designs are becoming part of mainstream statistical visualizations. Bringing together the research of two leaders in this field, "Visualizing Data Patterns with Micromaps" presents the many design variations and applications of micromaps, which link statistical information to an organized set of small maps. This full-color book helps readers simultaneously explore the statistical and geographic patterns in their data. After illustratin
Liver-cell patterning lab chip: mimicking the morphology of liver lobule tissue.
Ho, Chen-Ta; Lin, Ruei-Zeng; Chen, Rong-Jhe; Chin, Chung-Kuang; Gong, Song-En; Chang, Hwan-You; Peng, Hwei-Ling; Hsu, Long; Yew, Tri-Rung; Chang, Shau-Feng; Liu, Cheng-Hsien
2013-09-21
A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue of heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated and reported. By mimicking the basic morphology of liver tissue, the classic hepatic lobule, the lobule-mimetic-stellate-electrodes array was designed for cell patterning. Through DEP manipulation, well-defined and enhanced spatial electric field gradients were created for in-parallel manipulation of massive individual cells. With this liver-cell patterning labchip design, the original randomly distributed hepatic and endothelial cells inside the microfluidic chamber can be manipulated separately and aligned into the desired pattern that mimicks the morphology of liver lobule tissue. Experimental results showed that both hepatic and endothelial cells were orderly guided, snared, and aligned along the field-induced orientation to form the lobule-mimetic pattern. About 95% cell viability of hepatic and endothelial cells was also observed after cell-patterning demonstration via a fluorescent assay technique. The liver function of CYP450-1A1 enzyme activity showed an 80% enhancement for our engineered liver tissue (HepG2+HUVECs) compared to the non-patterned pure HepG2 for two-day culturing.
High Performance Embedded System for Real-Time Pattern Matching
Sotiropoulou, Calliope Louisa; The ATLAS collaboration; Gkaitatzis, Stamatios; Citraro, Saverio; Giannetti, Paola; Dell'Orso, Mauro
2016-01-01
We present an innovative and high performance embedded system for real-time pattern matching. This system is based on the evolution of hardware and algorithms developed for the field of High Energy Physics (HEP) and more specifically for the execution of extremely fast pattern matching for tracking of particles produced by proton-proton collisions in hadron collider experiments. A miniaturized version of this complex system is being developed for pattern matching in generic image processing applications. The design uses the flexibility of Field Programmable Gate Arrays (FPGAs) and the powerful Associative Memory Chip (ASIC) to achieve real-time performance. The system works as a contour identifier able to extract the salient features of an image. It is based on the principles of cognitive image processing, which means that it executes fast pattern matching and data reduction mimicking the operation of the human brain.
Macroscopic quantum effects in nonlinear optical patterns
International Nuclear Information System (INIS)
Gatti, A.; Lugiato, L.A.; Oppo, G.L.; Barnett, S.M.; Marzoli, I.
1998-01-01
We display the results of the numerical simulations of a set of Langevin equations, which describe the dynamics of a degenerate optical parametric oscillator in the Wigner representation. The scan of the threshold region shows the gradual transformation of a quantum image into a classical roll pattern. Thus the quantum image behaves as a precursor of the roll pattern which appear above threshold. In the fax field, suitable spatial correlation functions of intensity and field quadratures show unambiguously the quantum nature of fluctuations that generate the image, leading to effects of quantum noise reduction below the shot noise level and to the formulation of an EPR paradox. (author)
PATTERN SPEEDS OF BARS AND SPIRAL ARMS FROM Hα VELOCITY FIELDS
International Nuclear Information System (INIS)
Fathi, K.; Pinol-Ferrer, N.; Beckman, J. E.; MartInez-Valpuesta, I.; Hernandez, O.; Carignan, C.
2009-01-01
We have applied the Tremaine-Weinberg method to 10 late-type barred spiral galaxies using data cubes, in Hα emission, from the FaNTOmM and GHAFAS Fabry-Perot spectrometers. We have combined the derived bar (and/or spiral) pattern speeds with angular frequency plots to measure the corotation radii for the bars in these galaxies. We base our results on a combination of this method with a morphological analysis designed to estimate the corotation radius to bar-length ratio using two independent techniques on archival near-infrared images, and although we are aware of the limitation of the application of the Tremaine-Weinberg method using Hα observations, we find consistently excellent agreement between bar and spiral arm parameters derived using different methods. In general, the corotation radius, measured using the Tremaine-Weinberg method, is closely related to the bar length, measured independently from photometry and consistent with previous studies. Our corotation/bar-length ratios and pattern speed values are in good agreement with general results from numerical simulations of bars. In systems with identified secondary bars, we measure higher Hα velocity dispersion in the circumnuclear regions, whereas in all the other galaxies, we detect flat velocity dispersion profiles. In the galaxies where the bar is almost purely stellar, Hα measurements are missing, and the Tremaine-Weinberg method yields the pattern speeds of the spiral arms. The excellent agreement between the Tremaine-Weinberg method results and the morphological analysis and bar parameters in numerical simulations suggests that although the Hα emitting gas does not obey the continuity equation, it can be used to derive the bar pattern speed. In addition, we have analyzed the Hα velocity dispersion maps to investigate signatures of secular evolution of the bars in these galaxies. The increased central velocity dispersion in the galaxies with secondary bars suggests that the formation of inner
deJonge, R B; Bourchier, R S; Smith, S M
2017-06-01
Native insects can form novel associations with introduced invasive plants and use them as a food source. The recent introduction into eastern North America of a nonnative European vine, Vincetoxicum rossicum (Kleopow) Barbar., allows us to examine the initial response of a native chrysomelid beetle, Chrysochus auratus F., that feeds on native plants in the same family as V. rossicum (Apocynaceae). We tested C. auratus on V. rossicum and closely related or co-occurring native plants (Apocynum spp., Asclepias spp., and Solidago canadensis L.) using all life stages of the beetle in lab, garden, and field experiments. Experiments measured feeding (presence or absence and amount), survival, oviposition, and whether previous exposure to V. rossicum in the lab or field affected adult beetle feeding. Beetles fed significantly less on V. rossicum than on native Apocynum hosts. Adult beetles engaged in exploratory feeding on leaves of V. rossicum and survived up to 10 d. Females oviposited on V. rossicum, eggs hatched, and larvae fed initially on the roots; however, no larvae survived beyond second instar. Beetles collected from Apocynum cannabinum L. field sites intermixed with V. rossicum were less likely to feed on this novel nonnative host than those collected from colonies further from and less likely to be exposed to V. rossicum (>5 km). Our experimental work indicates that V. rossicum may act as an oviposition sink for C. auratus and that this native beetle has not adapted to survive on this recently introduced novel host plant. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Empirical high-latitude electric field models
International Nuclear Information System (INIS)
Heppner, J.P.; Maynard, N.C.
1987-01-01
Electric field measurements from the Dynamics Explorer 2 satellite have been analyzed to extend the empirical models previously developed from dawn-dusk OGO 6 measurements (J.P. Heppner, 1977). The analysis embraces large quantities of data from polar crossings entering and exiting the high latitudes in all magnetic local time zones. Paralleling the previous analysis, the modeling is based on the distinctly different polar cap and dayside convective patterns that occur as a function of the sign of the Y component of the interplanetary magnetic field. The objective, which is to represent the typical distributions of convective electric fields with a minimum number of characteristic patterns, is met by deriving one pattern (model BC) for the northern hemisphere with a +Y interplanetary magnetic field (IMF) and southern hemisphere with a -Y IMF and two patterns (models A and DE) for the northern hemisphere with a -Y IMF and southern hemisphere with a +Y IMF. The most significant large-scale revisions of the OGO 6 models are (1) on the dayside where the latitudinal overlap of morning and evening convection cells reverses with the sign of the IMF Y component, (2) on the nightside where a westward flow region poleward from the Harang discontinuity appears under model BC conditions, and (3) magnetic local time shifts in the positions of the convection cell foci. The modeling above was followed by a detailed examination of cases where the IMF Z component was clearly positive (northward). Neglecting the seasonally dependent cases where irregularities obscure pattern recognition, the observations range from reasonable agreement with the new BC and DE models, to cases where different characteristics appeared primarily at dayside high latitudes
A SIMPLE HETERODYNE TEMPORAL SPECKLE-PATTERN INTERFEROMETER
International Nuclear Information System (INIS)
Wong, W. O.; Gao, Z.; Lu, J.
2010-01-01
A common light path design of heterodyne speckle pattern interferometer based on temporal speckle pattern interferometry is proposed for non-contact, full-field and real-time continuous displacement measurement. Double frequency laser is produced by rotating a half wave plate. An experiment was carried out to measure the dynamic displacement of a cantilever plate for testing the proposed common path heterodyne speckle pattern interferometer. The accuracy of displacement measurement was checked by measuring the motion at the mid-point of the plate with a point displacement sensor.
Publication Growth in Biological Sub-Fields: Patterns, Predictability and Sustainability
Directory of Open Access Journals (Sweden)
Marco Pautasso
2012-11-01
Full Text Available Biologists are producing ever-increasing quantities of papers. The question arises of whether current rates of increase in scientific outputs are sustainable in the long term. I studied this issue using publication data from the Web of Science (1991–2010 for 18 biological sub-fields. In the majority of cases, an exponential regression explains more variation than a linear one in the number of papers published each year as a function of publication year. Exponential growth in publication numbers is clearly not sustainable. About 75% of the variation in publication growth among biological sub-fields over the two studied decades can be predicted by publication data from the first six years. Currently trendy fields such as structural biology, neuroscience and biomaterials cannot be expected to carry on growing at the current pace, because in a few decades they would produce more papers than the whole of biology combined. Synthetic and systems biology are problematic from the point of view of knowledge dissemination, because in these fields more than 80% of existing papers have been published over the last five years. The evidence presented here casts a shadow on how sustainable the recent increase in scientific publications can be in the long term.
Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements
Ren, D.
2015-01-01
Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to significantly reduce the probability of a non-uniform crack pattern - such as closely spaced cracks, meandering, and Y-cracks - by only slightly adjusting the amount of longitudinal steel. Non-unifor...
Directory of Open Access Journals (Sweden)
Dadang Dadang
2017-02-01
Full Text Available Storage pests remain one of the main problems in storage. The pest attacks occur not only in the field, but also in storage. Control should be done to maintain the quality of storedproducts. The environmentally friendly measures should be implemented to avoid negative impacts to the environment and human being. The objective of this research was to study the mortality and oviposition deterrence caused by powder and oil of six plant species against Callosobruchus sp. (Coleoptera: Bruchidae. Flowers of Eugenia aromatica, roots of Vetiveria zizanioides, leaves of Pogostemon cablin, seeds of Ricinus communis, seeds of Foeniculum vulgare, and stems of Cymbopogon citratus were air-dried and milled to yield powder. Oil of six plant species were purchased from local market. Oviposition deterrent bioassay was conducted by no-choice method for both powder and oil, while mortality bioassay was conducted by topical application and residual methods for plant oil only. Several plant species showed high biological activity to Callosobruchus sp. Powder of E. aromatica and oil of V. zizanioides caused high oviposition deterrence, while oil of V. zizanioides and E. aromatica caused high mortality.
Magnetic response to applied electrostatic field in external magnetic field
Energy Technology Data Exchange (ETDEWEB)
Adorno, T.C. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); University of Florida, Department of Physics, Gainesville, FL (United States); Gitman, D.M. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Shabad, A.E. [P. N. Lebedev Physics Institute, Moscow (Russian Federation)
2014-04-15
We show, within QED and other possible nonlinear theories, that a static charge localized in a finite domain of space becomes a magnetic dipole, if it is placed in an external (constant and homogeneous) magnetic field in the vacuum. The magnetic moment is quadratic in the charge, depends on its size and is parallel to the external field, provided the charge distribution is at least cylindrically symmetric. This magneto-electric effect is a nonlinear response of the magnetized vacuum to an applied electrostatic field. Referring to the simple example of a spherically symmetric applied field, the nonlinearly induced current and its magnetic field are found explicitly throughout the space; the pattern of the lines of force is depicted, both inside and outside the charge, which resembles that of a standard solenoid of classical magnetostatics. (orig.)
Multiple flow patterns and heat transfer in confined jet impingement
International Nuclear Information System (INIS)
Li Xianchang; Gaddis, J. Leo; Wang Ting
2005-01-01
The flow field of a 2-D laminar confined impinging slot jet is investigated. Numerical results indicate that there exist two different solutions in some range of geometric and flow parameters. The two steady flow patterns are obtained under identical boundary conditions but only with different initial flow fields. Two different exit boundary conditions are investigated with two commercial software packages to eliminate artificial or computational effects. The different flow patterns are observed to significantly affect the heat transfer. A flow visualization experiment is carried out to verify the computational results and both flow patterns are observed. The bifurcation mechanism is interpreted and discussed
Faraji, F.; Janssen, A.; van Rijn, P.C.J.; Sabelis, M.W.
2000-01-01
1. Kin recognition is important in many social insects, but has also been found in several nonsocial insects such as parasitoids, where it plays an important role in oviposition behaviour. In nonparasitic arthropods, however, the fitness of ovipositing females also depends on the oviposition
Simple model for polar cap convection patterns and generation of theta auroras
International Nuclear Information System (INIS)
Lyons, L.R.
1985-01-01
The simple addition of a uniform interplanetary magnetic field and the Earth's dipole magnetic field is used to evaluate electric field convection patterns over the polar caps that result from solar wind flow across open geomagnetic field lines. This model is found to account for observed polar-cap convection patterns as a function of the interplanetary magnetic field components B/sub y/ and B/sub z/. In particular, the model offers an explanation for sunward and antisunward convection over the polar caps for B/sub z/>0. Observed field-aligned current patterns within the polar cap and observed auroral arcs across the polar cap are also explained by the model. In addition, the model gives several predictions concerning the polar cap that should be testable. Effects of solar wind pressure and magnetospheric currents on magnetospheric electric and magnetic fields are neglected. That observed polar cap features are reproduced suggests that the neglected effects do not modify the large-scale topology of magnetospheric electric and magnetic fields along open polar cap field lines. Of course, the neglected effects significantly modify the magnetic geometry, so that the results of this paper are not quantitatively realistic and many details may be incorrect. Nevertheless, the model provides a simple explanation for many qualitative features of polar cap convection
Duda, Richard O; Stork, David G
2001-01-01
The first edition, published in 1973, has become a classic reference in the field. Now with the second edition, readers will find information on key new topics such as neural networks and statistical pattern recognition, the theory of machine learning, and the theory of invariances. Also included are worked examples, comparisons between different methods, extensive graphics, expanded exercises and computer project topics. An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.
Normalized burn ratios link fire severity with patterns of avian occurrence
Rose, Eli T.; Simons, Theodore R.; Klein, Rob; McKerrow, Alexa
2016-01-01
ContextRemotely sensed differenced normalized burn ratios (DNBR) provide an index of fire severity across the footprint of a fire. We asked whether this index was useful for explaining patterns of bird occurrence within fire adapted xeric pine-oak forests of the southern Appalachian Mountains.ObjectivesWe evaluated the use of DNBR indices for linking ecosystem process with patterns of bird occurrence. We compared field-based and remotely sensed fire severity indices and used each to develop occupancy models for six bird species to identify patterns of bird occurrence following fire.MethodsWe identified and sampled 228 points within fires that recently burned within Great Smoky Mountains National Park. We performed avian point counts and field-assessed fire severity at each bird census point. We also used Landsat™ imagery acquired before and after each fire to quantify fire severity using DNBR. We used non-parametric methods to quantify agreement between fire severity indices, and evaluated single season occupancy models incorporating fire severity summarized at different spatial scales.ResultsAgreement between field-derived and remotely sensed measures of fire severity was influenced by vegetation type. Although occurrence models using field-derived indices of fire severity outperformed those using DNBR, summarizing DNBR at multiple spatial scales provided additional insights into patterns of occurrence associated with different sized patches of high severity fire.ConclusionsDNBR is useful for linking the effects of fire severity to patterns of bird occurrence, and informing how high severity fire shapes patterns of bird species occurrence on the landscape.
Modification of parabolic dish antenna pattern using two symmetrically placed circular flat plates
Thorpe, Glen C.
1987-12-01
This study aims to formulate a method of predicting the far field pattern of a parabolic dish antenna with two moveable flat plates mounted symmetrically on either side of the feed horn. The approach taken has been to first analyze the radiation pattern of the antenna with the disks at certain heights out from the surface of the dish. To do this the near-field radiation in amplitude and phase was measured over a plane surface in the near-field and the values were then transformed into the far field using a Fast Fourier Transform. Far field pattern values of the antenna were directly measured for each setting of the plates. The results obtained from the Fast Fourier Transform of the near field data were in good agreement with the values obtained by measurement. Finally, an approximate model of the antenna was developed and implemented as a computer program. This model, while relatively unsophisticated, provided some insights into the changes in the near field phase distribution caused by the moveable circular flat plates.
Nonlinear dynamics of pattern formation and pattern recognition in the rabbit olfactory bulb
Baird, Bill
1986-10-01
A mathematical model of the process of pattern recognition in the first olfactory sensory cortex of the rabbit is presented. It explains the formation and alteration of spatial patterns in neural activity observed experimentally during classical Pavlovian conditioning. On each inspiration of the animal, a surge of receptor input enters the olfactory bulb. EEG activity recorded at the surface of the bulb undergoes a transition from a low amplitude background state of temporal disorder to coherent oscillation. There is a distinctive spatial pattern of rms amplitude in this oscillation which changes reliably to a second pattern during each successful recognition by the animal of a conditioned stimulus odor. When a new odor is paired as conditioned stimulus, these patterns are replaced by new patterns that stabilize as the animal adapts to the new environment. I will argue that a unification of the theories of pattern formation and associative memory is required to account for these observations. This is achieved in a model of the bulb as a discrete excitable medium with spatially inhomogeneous coupling expressed by a connection matrix. The theory of multiple Hopf bifurcations is employed to find coupled equations for the amplitudes of competing unstable oscillatory modes. These may be created in the system by proper coupling and selectively evoked by specific classes of inputs. This allows a view of limit cycle attractors as “stored” fixed points of a gradient vector field and thereby recovers the more familiar dynamical systems picture of associative memory.
Energy Technology Data Exchange (ETDEWEB)
Kim, Jong Hoon; Park, Jin Hong; Kim, Dae Yong [College of Medicine, Ulsan Univ., Seoul (Korea, Republic of)] [and others
2003-06-01
To suggest the optimal radiation fields after a surgical resection based on a nationwide survey on the principles of radiotherapy for rectal cancer in the Korean Patterns of Care Study. A consensus committee, composed of radiation oncologists from 18 hospitals in Seoul Metropolitan area, developed a survey format to analyze radiation oncologist's treatment principles for rectal cancer after a surgical resection. The survey format included 19 questions on the principles of defining field margins, and was sent to the radiation oncologists in charge of gastrointestinal malignancies in all Korean hospitals (48 hospitals). Thirty three (69%) oncologists replied. On the basis of the replies and literature review, the committee developed guidelines for the optimal radiation fields for rectal cancer. The following guidelines were developed: superior border between the lower tip of the L5 vertebral body and upper sacroiliac joint; inferior border 2-3 cm distal to the anastomosis in patient whose sphincter was saved, and 2-3 cm distal to the perineal scar in patients whose anal sphincter was sacrificed; anterior margin at the posterior tip of the symphysis pubis or 2-3 cm anterior to the vertebral body, to include the internal iliac lymph node and posterior margin 1.5-2 cm posterior to the anterior surface of the sacrum, to include the presacral space with enough margin. Comparison with the guidelines, the replies on the superior margin coincided in 23 cases (70%), the inferior margin after sphincter saving surgery in 13 (39%), the inferior margin after abdominoperineal resection in 32 (97%), the lateral margin in 32 (97%), the posterior margins in 32 (97%) and the anterior margin in 16 (45%). These recommendations should be tailored to each patient according to the clinical characteristics such as tumor location, pathological and operative findings, for the optimal treatment. The adequacy of these guidelines should be proved by following the Korean Patterns of Care
International Nuclear Information System (INIS)
Kim, Jong Hoon; Park, Jin Hong; Kim, Dae Yong
2003-01-01
To suggest the optimal radiation fields after a surgical resection based on a nationwide survey on the principles of radiotherapy for rectal cancer in the Korean Patterns of Care Study. A consensus committee, composed of radiation oncologists from 18 hospitals in Seoul Metropolitan area, developed a survey format to analyze radiation oncologist's treatment principles for rectal cancer after a surgical resection. The survey format included 19 questions on the principles of defining field margins, and was sent to the radiation oncologists in charge of gastrointestinal malignancies in all Korean hospitals (48 hospitals). Thirty three (69%) oncologists replied. On the basis of the replies and literature review, the committee developed guidelines for the optimal radiation fields for rectal cancer. The following guidelines were developed: superior border between the lower tip of the L5 vertebral body and upper sacroiliac joint; inferior border 2-3 cm distal to the anastomosis in patient whose sphincter was saved, and 2-3 cm distal to the perineal scar in patients whose anal sphincter was sacrificed; anterior margin at the posterior tip of the symphysis pubis or 2-3 cm anterior to the vertebral body, to include the internal iliac lymph node and posterior margin 1.5-2 cm posterior to the anterior surface of the sacrum, to include the presacral space with enough margin. Comparison with the guidelines, the replies on the superior margin coincided in 23 cases (70%), the inferior margin after sphincter saving surgery in 13 (39%), the inferior margin after abdominoperineal resection in 32 (97%), the lateral margin in 32 (97%), the posterior margins in 32 (97%) and the anterior margin in 16 (45%). These recommendations should be tailored to each patient according to the clinical characteristics such as tumor location, pathological and operative findings, for the optimal treatment. The adequacy of these guidelines should be proved by following the Korean Patterns of Care Study
Directory of Open Access Journals (Sweden)
Joseph L Spencer
Full Text Available BACKGROUND: Interest in the cultivation of biomass crops like the C4 grass Miscanthus x giganteus (Miscanthus is increasing as global demand for biofuel grows. In the US, Miscanthus is promoted as a crop well-suited to the Corn Belt where it could be cultivated on marginal land interposed with maize and soybean. Interactions (direct and indirect of Miscanthus, maize, and the major Corn Belt pest of maize, the western corn rootworm, (Diabrotica virgifera virgifera LeConte, WCR are unknown. Adding a perennial grass/biomass crop to this system is concerning since WCR is adapted to the continuous availability of its grass host, maize (Zea mays. METHODOLOGY/PRINCIPAL FINDINGS: In a greenhouse and field study, we investigated WCR development and oviposition on Miscanthus. The suitability of Miscanthus for WCR development varied across different WCR populations. Data trends indicate that WCR populations that express behavioural resistance to crop rotation performed as well on Miscanthus as on maize. Over the entire study, total adult WCR emergence from Miscanthus (212 WCR was 29.6% of that from maize (717 WCR. Adult dry weight was 75-80% that of WCR from maize; female emergence patterns on Miscanthus were similar to females developing on maize. There was no difference in the mean no. of WCR eggs laid at the base of Miscanthus and maize in the field. CONCLUSIONS/SIGNIFICANCE: Field oviposition and significant WCR emergence from Miscanthus raises many questions about the nature of likely interactions between Miscanthus, maize and WCR and the potential for Miscanthus to act as a refuge or reservoir for Corn Belt WCR. Responsible consideration of the benefits and risks associated with Corn Belt Miscanthus are critical to protecting an agroecosystem that we depend on for food, feed, and increasingly, fuel. Implications for European agroecosystems in which Miscanthus is being proposed are also discussed in light of the WCR's recent invasion into Europe.
Directory of Open Access Journals (Sweden)
Rachael K Walsh
Full Text Available Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.
Concept of a data base for signal patterns
International Nuclear Information System (INIS)
Olma, B.
1985-01-01
The many requirements made on the storage, administration and handling of signal patterns of stationary random signal patterns and multi-channel transient signal patterns are discussed. For the field of loose part detection, the concept of a data base is presented for structure-borne noise burst patterns. Chapter 2 describes the measuring principle of structure-borne noise monitoring. Chapter 3 gives a summary of the requirements made on the automation of measured data recording; chapter 4 compiles requirements made on the data base. Chapter 5 describes the concept developed for a burst pattern data base; chapter 6 shows the organization of the data base, and chapter 7 reflects the present state of application. (orig./HP) [de
Patterned magnetite films prepared via soft lithography and thermal decomposition
International Nuclear Information System (INIS)
An Lijuan; Li, Zhaoqiang; Li Wei; Nie Yaru; Chen Zhimin; Wang Yanping; Yang Bai
2006-01-01
A method for the fabrication of patterned magnetite (Fe 3 O 4 ) films is presented. We first prepared an ordered 2D array of Fe(acac) 3 through a selective deposition technique on patterned self-assembled monolayers. Using thermal decomposition at elevated temperature (300 o C), we transformed the patterned Fe(acac) 3 into patterned Fe 3 O 4 films in a short reaction time. These patterned films have been confirmed by using optical photographs, field emission scanning electron microscopy and atomic force microscopy
Knutson, Allen E; Muegge, Mark A
2010-06-01
Field observations from pecan, Carya illinoinensis (Wangenh.) Koch, orchards in Texas were used to develop and validate a degree-day model of cumulative proportional adult flight and oviposition and date of first observed nut entry by larvae of the first summer generation of the pecan nut casebearer, Acrobasis nuxvorella Nuenzig (Lepidoptera: Pyralidae). The model was initiated on the date of first sustained capture of adults in pheromone traps. Mean daily maximum and minimum temperatures were used to determine the sum of degree-days from onset to 99% moth flight and oviposition and the date on which first summer generation larvae were first observed penetrating pecan nuts. Cumulative proportional oviposition (y) was described by a modified Gompertz equation, y = 106.05 x exp(-(exp(3.11 - 0.00669 x (x - 1), with x = cumulative degree-days at a base temperature of 3.33 degrees C. Cumulative proportional moth flight (y) was modeled as y = 102.62 x exp(- (exp(1.49 - 0.00571 x (x - 1). Model prediction error for dates of 10, 25, 50, 75, and 90% cumulative oviposition was 1.3 d and 83% of the predicted dates were within +/- 2 d of the observed event. Prediction error for date of first observed nut entry was 2.2 d and 77% of model predictions were within +/- 2 d of the observed event. The model provides ample lead time for producers to implement orchard scouting to assess pecan nut casebearer infestations and to apply an insecticide if needed to prevent economic loss.
Acoustic Tweezing and Patterning of Concentration Fields in Microfluidics
DEFF Research Database (Denmark)
Karlsen, Jonas Tobias; Bruus, Henrik
2017-01-01
that weakly perturb the fluid density and speed of sound is presented and applied to study manipulation of concentration fields in rectangular-channel acoustic eigenmodes and in Bessel-function acoustic vortices. In the first example, methods to obtain horizontal and vertical multilayer stratification...
Reichman, Rivka; Yates, Scott R.; Skaggs, Todd H.; Rolston, Dennis E.
2013-02-01
Pesticide volatilization from agricultural soils is one of the main pathways in which pesticides are dispersed in the environment and affects ecosystems including human welfare. Thus, it is necessary to have accurate knowledge of the various physical and chemical mechanisms that affect volatilization rates from field soils. A verification of the influence of soil moisture modeling on the simulated volatilization rate, soil temperature and soil-water content is presented. Model simulations are compared with data collected in a field study that measured the effect of soil moisture on diazinon volatilization. These data included diurnal changes in volatilization rate, soil-water content, and soil temperature measured at two depths. The simulations were performed using a comprehensive non-isothermal model, two water retention functions, and two soil surface resistance functions, resulting in four tested models. Results show that the degree of similarity between volatilization curves simulated using the four models depended on the initial water content. Under fairly wet conditions, the simulated curves mainly differ in the magnitude of their deviation from the measured values. However, under intermediate and low moisture conditions, the simulated curves also differed in their pattern (shape). The model prediction accuracy depended on soil moisture. Under normal practices, where initial soil moisture is about field capacity or higher, a combination of Brooks and Corey water retention and the van de Grind and Owe soil surface resistance functions led to the most accurate predictions. However, under extremely dry conditions, when soil-water content in the top 1 cm is below the volumetric threshold value, the use of a full-range water retention function increased prediction accuracy. The different models did not affect the soil temperature predictions, and had a minor effect on the predicted soil-water content of Yolo silty clay soil.
Vinson , S.; Frankie , Gordon; Rao , Asha
2011-01-01
International audience; Coelioxys chichimeca is a cleptoparasite and an important cause of mortality for several woodhole nesting pollinator bees in Costa Rica. We studied the behavior of this parasitic bee towards one of the more common host bee, Centris (Heterocentris) bicornuta. The female parasitic C. chichimeca were attracted to host bee, C. bicornuta nest cells that contained pollen, but only exhibited interest in entering and ovipositing when these host cells contained nectar. This int...
Chang, Wen-Chi; Chen, Yu-Chi; Chien, Chih-Jen; Wang, An-Bang; Lee, Chih-Kung
2011-04-01
A testing system contains an advanced vibrometer/interferometer device (AVID) and a high-speed electronic speckle pattern interferometer (ESPI) was developed. AVID is a laser Doppler vibrometer that can be used to detect single-point linear and angular velocity with DC to 20 MHz bandwidth and with nanometer resolution. In swept frequency mode, frequency response from mHz to MHz of the structure of interest can be measured. The ESPI experimental setup can be used to measure full-field out-of-plane displacement. A 5-1 phase shifting method and a correlation algorithm were used to analyze the phase difference between the reference signal and the speckle signal scattered from the sample surface. In order to show the efficiency and effectiveness of AVID and ESPI, we designed a micro-speaker composed of a plate with fixed boundaries and two piezo-actuators attached to the sides of the plate. The AVID was used to measure the vibration of one of the piezo-actuators and the ESPI was adopted to measure the two-dimensional out-of-plane displacement of the plate. A microphone was used to measure the acoustic response created by the micro-speaker. Driving signal includes random signal, sinusoidal signal, amplitude modulated high-frequency carrier signal, etc. Angular response induced by amplitude modulated high-frequency carrier signal was found to be significantly narrower than the frequency responses created by other types of driving signals. The validity of our newly developed NDE system are detailed by comparing the relationship between the vibration signal of the micro-speaker and the acoustic field generated.
Enforced Scale Selection in Field Theories of Mechanical and Biological Systems
DEFF Research Database (Denmark)
Tarp, Jens Magelund
The collective motion of driven or self-propelled interacting units is in many natural systems known to produce complex patterns. This thesis considers two continuum field theories commonly used in describing pattern formation and dynamics: The first one, the phase field crystal model, which...
Classical patterns of interstitial lung diseases
International Nuclear Information System (INIS)
Mueller-Mang, C.
2014-01-01
High resolution computed tomography (HRCT) is the most important non-invasive tool in the diagnostics and follow-up of patients with interstitial lung disease (ILD). A systematic review of the HRCT patterns of ILD was carried out and the most relevant differential diagnoses are discussed in order to provide a road map for the general radiologist to successfully navigate the complex field of ILD. Using HRCT four basic patterns of ILD can be identified: linear and reticular patterns, the nodular pattern, the high attenuation and low attenuation patterns. These patterns can be further differentiated according to their localization within the secondary pulmonary lobule (SPL), e.g. centrilobular or perilymphatic and their distribution within the lungs (e.g. upper or lower lobe predominance). Relevant clinical data, such as smoking history and course of the disease provide useful additional information in the diagnosis of ILD. On the basis of the pattern and anatomical distribution on HRCT, an accurate diagnosis can be achieved in some cases of ILD; however, due to morphological and clinical overlap the final diagnosis of many ILDs requires close cooperation between clinicians, radiologists and pathologists. (orig.) [de
Directory of Open Access Journals (Sweden)
J.P.G.F. Silva
2012-01-01
, T. pallida (leaves, A. indica (almonds, Chenopodium ambrosioides L. (inflorescence + leaves + branches and Mentha pulegium L. (leaves on Bemisia tabaci biotype B in squash, by assays of repellence and oviposition deterrence. In free choice tests, the attractiveness and determination of the rate of repellence (with 6, 24 and 48 hours after application of the extracts were evaluated. The oviposition was observed after the third counting of the number of adults. The extract of leaves of M. pulegium showed repellence and oviposition deterrence to B. tabaci biotype B and may be recommended as an alternative in the insect management.
The bee, the flower and the electric field
Directory of Open Access Journals (Sweden)
Robert Daniel
2016-01-01
Full Text Available Insects use several different senses to forage on flowers, and detect floral cues such as color, shape, pattern, humidity and chemical volatiles. This presentation will present our discovery of a previously unappreciated sensory capacity in bumblebees (Bombus terrestris: the detection of floral electric fields. We show that these floral fields act as informational cues, and that they can be affected by the visit of naturally electrically charged bees. Like visual cues, floral electric fields exhibit variations in pattern and structure, which can be discriminated by bumblebees. We also show that such electric field information contributes to the complex array of floral cues that together improve a pollinator’s memory of floral rewards. Floral electric fields arise from complex interactions with the surrounding atmosphere, an interaction between plants and their environment that not well understood. Because floral electric fields can change within seconds, this new sensory modality - electrostatic field detection- may facilitate rapid and dynamic communication between flowers and their pollinators.
Pattern-reversal electroretinograms in unilateral glaucoma.
Wanger, P; Persson, H E
1983-06-01
Pattern-reversal and flash electroretinograms (ERG) and oscillatory potentials (OP) were recorded from 11 patients with unilateral glaucoma. All glaucomatous eyes had reduced amplitudes both compared to the opposite eye in the same patient and to reference values. In 10 of the 11 cases this reduction was below the level of normal variation. The difference in pattern-reversal ERG amplitude means from glaucomatous and opposite eyes was statistically significant. No differences were observed in flash ERGs or OPs. The histopathologic correlate to the visual field defects in glaucoma is retinal ganglion cell degeneration. The present electrophysiologic findings support the view, based on results from animal experiments, that the pattern-reversal ERG reflects ganglion cell activity.
Andrade-Ochoa, Sergio; Sánchez-Aldana, Daniela; Chacón-Vargas, Karla Fabiola; Rivera-Chavira, Blanca E.; Camacho, Alejandro D.; Nogueda-Torres, Benjamín
2018-01-01
The larvicidal activity of essential oils cinnamon (Cinnamomum verum J. Presl), Mexican lime (Citrus aurantifolia Swingle) cumin (Cuminum cyminum Linnaeus), clove (Syzygium aromaticum (L.) Merr. & L.M.Perry), laurel (Laurus nobilis Linnaeus), Mexican oregano (Lippia berlandieri Schauer) and anise (Pimpinella anisum Linnaeus)) and their major components are tested against larvae and pupae of Culex quinquefasciatus Say. Third instar larvae and pupae are used for determination of lethality and mortality. Essential oils with more than 90% mortality after a 30-min treatment are evaluated at different time intervals. Of the essential oils tested, anise and Mexican oregano are effective against larvae, with a median lethal concentration (LC50) of 4.7 and 6.5 µg/mL, respectively. Anise essential oil and t-anethole are effective against pupae, with LC50 values of 102 and 48.7 µg/mL, respectively. Oregano essential oil and carvacrol also have relevant activities. A kinetic analysis of the larvicidal activity, the oviposition deterrent effect and assays of the effects of the binary mixtures of chemical components are undertaken. Results show that anethole has synergistic effects with other constituents. This same effect is observed for carvacrol and thymol. Limonene shows antagonistic effect with β-pinene. The high larvicidal and pupaecidal activities of essential oils and its components demonstrate that they can be potential substitutes for chemical compounds used in mosquitoes control programs. PMID:29443951
Directory of Open Access Journals (Sweden)
Snoussi Sarra
2012-02-01
Full Text Available Abstract Background Salmonella enterica serovar Hadar (S. Hadar is a highly prevalent foodborne pathogen and therefore a major cause of human gastroenteritis worldwide. Outer membrane proteins whose production is often regulated by environmental conditions also play important roles in the adaptability of bacterial pathogens to various environments. Results The present study investigated the adaptation of S. Hadar under the effect of acute static magnetic field exposure (200 mT, 9 h and the impact on the outer membrane protein pattern. Via two-dimensional electrophoresis (2-DE and LC-MS/MS spectrometry, we compared the proteome of enriched-outer membrane fraction before and after exposure to a magnetic field. A total of 11 proteins, displaying more than a two-fold change, were differentially expressed in exposed cells, among which 7 were up-regulated and 4 down-regulated. These proteins were involved in the integrity of cell envelope (TolB, Pal, in the response to oxidative stress (OmpW, dihydrolipoamide dehydrogenase, UspF, in the oxidative stress status (bacterioferritin, in virulence (OmpX, Yfgl or in motility (FlgE and UspF. Complementary experiments associated the down-regulation of FlgE and UspF with an alteration of swarming, a flagella-driven motility, under SMF. Furthermore, the antibiotic disc diffusion method confirmed a decrease of gentamicin susceptibility in exposed cells. This decrease could be partly associated with the up-regulation of TolC, outer membrane component of an efflux pump. OmpA, a multifunctional protein, was up-regulated. Conclusions SMF (200 mT seems to maintain the cell envelope integrity and to submit the exposed cells to an oxidative stress. Some alterations suggest an increase of the ability of exposed cells to form biofilms.
New public dataset for spotting patterns in medieval document images
En, Sovann; Nicolas, Stéphane; Petitjean, Caroline; Jurie, Frédéric; Heutte, Laurent
2017-01-01
With advances in technology, a large part of our cultural heritage is becoming digitally available. In particular, in the field of historical document image analysis, there is now a growing need for indexing and data mining tools, thus allowing us to spot and retrieve the occurrences of an object of interest, called a pattern, in a large database of document images. Patterns may present some variability in terms of color, shape, or context, making the spotting of patterns a challenging task. Pattern spotting is a relatively new field of research, still hampered by the lack of available annotated resources. We present a new publicly available dataset named DocExplore dedicated to spotting patterns in historical document images. The dataset contains 1500 images and 1464 queries, and allows the evaluation of two tasks: image retrieval and pattern localization. A standardized benchmark protocol along with ad hoc metrics is provided for a fair comparison of the submitted approaches. We also provide some first results obtained with our baseline system on this new dataset, which show that there is room for improvement and that should encourage researchers of the document image analysis community to design new systems and submit improved results.
Roux, Emmanuel; de Fátima Venâncio, Annamaria; Girres, Jean-François; Romaña, Christine A
2011-11-01
While the former part of this back-to-back paper dealt with the identification of multi-scale spatial patterns associated with the presence, abundance and dispersion of the insect vectors (Triatominae) of Chagas disease, this latter part examines the need for pattern characterisation by means of detailed data on environmental, residential, peri-domiciliary and human behaviour. The study site was, in both cases, a single village situated in Bahia, Brazil, wherefrom the data were collected through field observation and a standardised questionnaire, while the environmental characteristics were derived from satellite images and landscape characterisation. Following this, factorial analysis of mixed group (FAMG), an exploratory data analysis method, was applied to "mine" the huge dataset in a hierarchical way and to evaluate the relative impact of different factors such as the surrounding environment, the domiciliary/peri-domiciliary space properties and the presence of domestic animals. In the study village, five principal "districts" associated with different possible causes of infestation were identified. The results favour the role of depressions of the ground surface due to collapse of karstic subsoil (dolines) and open rock faces as infestation sources, vector attraction by outdoor lighting, risk of insect domiciliation in dwellings constructed without finishing materials and associated with apparent disorder. Ultimately, this study not only provides the basic information needed for decision-making and specification of vector control in the study village, but offers also a knowledge-base for more general control strategies in the region.
Faraday instability on patterned surfaces
Feng, Jie; Rubinstein, Gregory; Jacobi, Ian; Stone, Howard
2013-11-01
We show how micro-scale surface patterning can be used to control the onset of the Faraday instability in thin liquid films. It is well known that when a liquid film on a planar substrate is subject to sufficient vibrational accelerations, the free surface destabilizes, exhibiting a family of non-linear standing waves. This instability remains a canonical problem in the study of spontaneous pattern formation, but also has practical uses. For example, the surface waves induced by the Faraday instability have been studied as a means of enhanced damping for mechanical vibrations (Genevaux et al. 2009). Also the streaming within the unstable layer has been used as a method for distributing heterogeneous cell cultures on growth medium (Takagi et al. 2002). In each of these applications, the roughness of the substrate significantly affects the unstable flow field. We consider the effect of patterned substrates on the onset and behavior of the Faraday instability over a range of pattern geometries and feature heights where the liquid layer is thicker than the pattern height. Also, we describe a physical model for the influence of patterned roughness on the destabilization of a liquid layer in order to improve the design of practical systems which exploit the Faraday instability.
Description and recognition of patterns in stochastic signals. [Electroencephalograms
Energy Technology Data Exchange (ETDEWEB)
Flik, T [Technische Univ. Berlin (F.R. Germany). Informatik-Forschungsgruppe Rechnerorganisation und Schaltwerke
1975-10-01
A method is shown for the description and recognition of patterns in stochastic signals such as electroencephalograms. For pattern extraction the signal is segmented at times of minimum amplitudes. The describing features consist of geometric values of the so defined patterns. The classification algorithm is based on the regression analysis, which is well known in the field of character recognition. For an economic classification a method is proposed which reduces the number of features. The quality of this pattern recognition method is demonstrated by the detection of spike wave complexes in electroencephalograms. The pattern description and recognition are provided for processing on a digital computer. (DE)
Patterns of functional vision loss in glaucoma determined with archetypal analysis
Elze, Tobias; Pasquale, Louis R.; Shen, Lucy Q.; Chen, Teresa C.; Wiggs, Janey L.; Bex, Peter J.
2015-01-01
Glaucoma is an optic neuropathy accompanied by vision loss which can be mapped by visual field (VF) testing revealing characteristic patterns related to the retinal nerve fibre layer anatomy. While detailed knowledge about these patterns is important to understand the anatomic and genetic aspects of glaucoma, current classification schemes are typically predominantly derived qualitatively. Here, we classify glaucomatous vision loss quantitatively by statistically learning prototypical patterns on the convex hull of the data space. In contrast to component-based approaches, this method emphasizes distinct aspects of the data and provides patterns that are easier to interpret for clinicians. Based on 13 231 reliable Humphrey VFs from a large clinical glaucoma practice, we identify an optimal solution with 17 glaucomatous vision loss prototypes which fit well with previously described qualitative patterns from a large clinical study. We illustrate relations of our patterns to retinal structure by a previously developed mathematical model. In contrast to the qualitative clinical approaches, our results can serve as a framework to quantify the various subtypes of glaucomatous visual field loss. PMID:25505132
Clifford Fourier transform on vector fields.
Ebling, Julia; Scheuermann, Gerik
2005-01-01
Image processing and computer vision have robust methods for feature extraction and the computation of derivatives of scalar fields. Furthermore, interpolation and the effects of applying a filter can be analyzed in detail and can be advantages when applying these methods to vector fields to obtain a solid theoretical basis for feature extraction. We recently introduced the Clifford convolution, which is an extension of the classical convolution on scalar fields and provides a unified notation for the convolution of scalar and vector fields. It has attractive geometric properties that allow pattern matching on vector fields. In image processing, the convolution and the Fourier transform operators are closely related by the convolution theorem and, in this paper, we extend the Fourier transform to include general elements of Clifford Algebra, called multivectors, including scalars and vectors. The resulting convolution and derivative theorems are extensions of those for convolution and the Fourier transform on scalar fields. The Clifford Fourier transform allows a frequency analysis of vector fields and the behavior of vector-valued filters. In frequency space, vectors are transformed into general multivectors of the Clifford Algebra. Many basic vector-valued patterns, such as source, sink, saddle points, and potential vortices, can be described by a few multivectors in frequency space.
Where Do I Look? Preservice Teachers' Classroom Observation Patterns
Young, Teresa; Bender-Slack, Delane
2011-01-01
During field experiences, preservice teachers are typically required to observe mentor teachers in schools, but what exactly are they seeing? This research examined the patterns and variations that existed with regard to preservice teachers' classroom observations during recent field experiences. Data were collected from 24 preservice teachers…
Hyperbolic-symmetry vector fields.
Gao, Xu-Zhen; Pan, Yue; Cai, Meng-Qiang; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian
2015-12-14
We present and construct a new kind of orthogonal coordinate system, hyperbolic coordinate system. We present and design a new kind of local linearly polarized vector fields, which is defined as the hyperbolic-symmetry vector fields because the points with the same polarization form a series of hyperbolae. We experimentally demonstrate the generation of such a kind of hyperbolic-symmetry vector optical fields. In particular, we also study the modified hyperbolic-symmetry vector optical fields with the twofold and fourfold symmetric states of polarization when introducing the mirror symmetry. The tight focusing behaviors of these vector fields are also investigated. In addition, we also fabricate micro-structures on the K9 glass surfaces by several tightly focused (modified) hyperbolic-symmetry vector fields patterns, which demonstrate that the simulated tightly focused fields are in good agreement with the fabricated micro-structures.
Sheng, Sheng; Ling, Meng; Fu-An, Wu; Baoping, Li
2015-01-01
Foraging parasitoids often must estimate local risk of predation just as they must estimate local patch value. Here, we investigate the effects a generalist predator Chlaenius bioculatus (Coleoptera: Carabidae), has on the oviposition behavior and the patch residence decisions of a solitary parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) in response to the varying host quality of Spodoptera litura (Lepidoptera: Noctuidae) larvae (L2 and L4). M. pulchricornis attacked more L4 than on L2 hosts, with the difference in attack rate varying depending on predation treatments, greater in the presence (either actively feeding or not) of the predator than in the absence of it. The parasitoid attacked fewer L2 and L4 hosts when the predator was actively feeding than when it was not feeding or not present in the patch. M. pulchricornis decreased the patch leaving tendency with increasing rejections of hosts, but increased the tendency in response to the presence of the predator as compared with the absence of it, and furthermore, increased the patch leaving tendency when the predator was actively feeding as compared with when it was not. Our study suggests that M. pulchricornis can exploit high quality patches while minimizing predation risk, by attacking more hosts in high quality patches while reducing total patch time in response to risk of predation. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.
Experimental signature of scaling violation implied by field theories
International Nuclear Information System (INIS)
Tung, W.
1975-01-01
Renormalizable field theories are found to predict a surprisingly specific pattern of scaling violation in deep inelastic scattering. Comparison with experiments is discussed. The feasibility of distinguishing asymptotically free field theories from conventional field theories is evaluated
Directory of Open Access Journals (Sweden)
E.J. Souza
2009-02-01
Full Text Available Foram selecionados 20 equídeos naturalmente infestados por Anocentor nitens, dos quais seus pavilhões auriculares foram submetidos a quatro tratamentos distintos: gel associado a Beauveria bassiana, apenas gel, apenas B. bassiana e um grupo-controle. Procederam-se à contagem e ao registro do número total de fêmeas adultas (>3mm em cada pavilhão auricular, nos dias 0, 1, 4, 7, 11, 14, 18, 21, 25 e 28, para cálculo do percentual de controle. Foram coletadas e mantidas em laboratório 20 fêmeas pertencentes a cada tratamento, para cálculo dos períodos de pré-postura, postura, incubação e eclosão, e peso médio das posturas. No grupo tratado com o composto gel associado a B. bassiana, observou-se percentual de controle maior que 50%, entre o 4º e o 25º dia, assim como decréscimo progressivo do peso médio da postura das fêmeas coletadas no período entre o 7º e 14º dia. Para os outros tratamentos, o percentual de controle manteve-se abaixo de 20%, e o peso da postura não apresentou diferença significativa. Os percentuais de controle, assim como as reduções no peso médio da postura, sugerem que a utilização do composto gel associado a B. bassiana potencializou a virulência do entomopatógeno.Twenty horses naturally infected by Anocentor nitens were selected and their auricular pinna were submitted to four treatments: gel associated with Beauveria bassiana, gel only, B. bassiana only, and a control group. The count and the register of the total number of grown up tick females (>3mm were performed in each auricular pinna on days 0, 1, 4, 7, 11, 14, 18, 21, 25, and 28 for the calculus of percentage of control. Twenty females from each treatment were collected and maintained in laboratory, to calculate the periods of pre-oviposition, oviposition, incubation, and hatching and mean weight of oviposition. In the group treated with the gel associated to B. bassiana, it was observed a control percentage higher than 50% from the 4º
Degradation patterns of silicone-based dielectric elastomers in electrical fields
DEFF Research Database (Denmark)
Yu, Liyun; Madsen, Frederikke Bahrt; Skov, Anne Ladegaard
2017-01-01
. This shortcoming has been attempted optimized through different approaches during recent years. Material optimization with the sole purpose of increasing the dielectric permittivity may lead to the introduction of problematic phenomena such as premature electrical breakdown due to high leakage currents of the thin...... elastomer film. Within this work, electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers are investigated. Results showed that different types of polymer backbone chemistries lead to differences in electrical breakdown patterns, which were revealed through SEM imaging...
Workflow patterns the definitive guide
Russell, Nick; ter Hofstede, Arthur H M
2016-01-01
The study of business processes has emerged as a highly effective approach to coordinating an organization's complex service- and knowledge-based activities. The growing field of business process management (BPM) focuses on methods and tools for designing, enacting, and analyzing business processes. This volume offers a definitive guide to the use of patterns, which synthesize the wide range of approaches to modeling business processes. It provides a unique and comprehensive introduction to the well-known workflow patterns collection -- recurrent, generic constructs describing common business process modeling and execution scenarios, presented in the form of problem-solution dialectics. The underlying principles of the patterns approach ensure that they are independent of any specific enabling technology, representational formalism, or modeling approach, and thus broadly applicable across the business process modeling and business process technology domains. The authors, drawing on extensive research done by...
2014-04-05
in 50 L trash cans. Oak leaves of Quercus alba (L.) and Q. rubra (L.) were used because this infusion elicits oviposition responses from container...105 ha in area (Fig. 2), whereas, the control site was in Union Beach , NJ (40.2650 lat., - 74.71026 long.) and spanned 181 ha. Both the treatment and...people/km2) than Union Beach (1384.7 people/km2). We initially intended to assess pyriproxyfen-based area-wide autodissemination by treating 25% of an
Decadal period external magnetic field variations determined via eigenanalysis
DEFF Research Database (Denmark)
Shore, R. M.; Whaler, K. A.; Macmillan, S.
2016-01-01
to a full solar cycle. Our analysis focuses on geomagnetically quiet days and middle to low latitudes. We use the climatological eigenanalysis technique called empirical orthogonal functions (EOFs), which allows us to identify discrete spatiotemporal patterns with no a priori specification of their geometry...... mean external field distribution. Separate patterns of semiannual and solar-cycle-length periods appear to stem from the amplitude modulations of spatially fixed background fields....
Do pattern recognition skills transfer across sports? A preliminary analysis.
Smeeton, Nicholas J; Ward, Paul; Williams, A Mark
2004-02-01
The ability to recognize patterns of play is fundamental to performance in team sports. While typically assumed to be domain-specific, pattern recognition skills may transfer from one sport to another if similarities exist in the perceptual features and their relations and/or the strategies used to encode and retrieve relevant information. A transfer paradigm was employed to compare skilled and less skilled soccer, field hockey and volleyball players' pattern recognition skills. Participants viewed structured and unstructured action sequences from each sport, half of which were randomly represented with clips not previously seen. The task was to identify previously viewed action sequences quickly and accurately. Transfer of pattern recognition skill was dependent on the participant's skill, sport practised, nature of the task and degree of structure. The skilled soccer and hockey players were quicker than the skilled volleyball players at recognizing structured soccer and hockey action sequences. Performance differences were not observed on the structured volleyball trials between the skilled soccer, field hockey and volleyball players. The skilled field hockey and soccer players were able to transfer perceptual information or strategies between their respective sports. The less skilled participants' results were less clear. Implications for domain-specific expertise, transfer and diversity across domains are discussed.
Applications of evolutionary computation in image processing and pattern recognition
Cuevas, Erik; Perez-Cisneros, Marco
2016-01-01
This book presents the use of efficient Evolutionary Computation (EC) algorithms for solving diverse real-world image processing and pattern recognition problems. It provides an overview of the different aspects of evolutionary methods in order to enable the reader in reaching a global understanding of the field and, in conducting studies on specific evolutionary techniques that are related to applications in image processing and pattern recognition. It explains the basic ideas of the proposed applications in a way that can also be understood by readers outside of the field. Image processing and pattern recognition practitioners who are not evolutionary computation researchers will appreciate the discussed techniques beyond simple theoretical tools since they have been adapted to solve significant problems that commonly arise on such areas. On the other hand, members of the evolutionary computation community can learn the way in which image processing and pattern recognition problems can be translated into an...
A System for Harvesting Eggs from the Pink-Spotted Lady Beetle
Directory of Open Access Journals (Sweden)
Margaret L. Allen
2012-01-01
Full Text Available We describe a system for harvesting eggs from a predatory insect, the pink-spotted lady beetle, Coleomegilla maculata De Geer (Coleoptera: Coccinellidae. Adult beetles placed in square, transparent containers that included oviposition substrates hanging from the top of the cage deposited eggs on the materials provided. We harvested eggs from these substrates in quantities sufficient for either destructive sampling or synchronous development of larvae. We evaluated effects of crowding inside cages; effects of a chemical attractant on oviposition behavior; egg cannibalism. Females preferred a textured surface rather than a smooth, waxy one for laying eggs. Crowding inhibited oviposition of beetles. Presence of a chemical attractant (methyl salicylate did not significantly improve oviposition. This paper describes an inexpensive system for harvesting eggs from C. maculata. Refinement of this system should improve oviposition and reduce cannibalism.
A Compact RFID Reader Antenna for UHF Near-Field and Far-Field Operations
Directory of Open Access Journals (Sweden)
Lai Xiao zheng
2013-01-01
Full Text Available A compact loop antenna is presented for mobile ultrahigh frequency (UHF radio frequency identification (RFID application. This antenna, printed on a 0.8 mm thick FR4 substrate with a small size of 31 mm × 31 mm, achieves good impedance bandwidth from 897 to 928 MHz, which covers USA RFID Band (902–928 MHz. The proposed loop configuration, with a split-ring resonator (SRR coupled inside it, demonstrates strong and uniform magnetic field distribution in the near-field antenna region. Its linearly polarized radiation pattern provides available far-field gain. Finally, the reading capabilities of antenna are up to 56 mm for near-field and 1.05 m for far-field UHF RFID operations, respectively.
Patterns of Gram-stained fecal flora as a quick diagnostic marker in patients with severe SIRS.
Shimizu, Kentaro; Ogura, Hiroshi; Tomono, Kazunori; Tasaki, Osamu; Asahara, Takashi; Nomoto, Koji; Morotomi, Masami; Matsushima, Asako; Nakahori, Yasutaka; Yamano, Shuhei; Osuka, Akinori; Kuwagata, Yasuyuki; Sugimoto, Hisashi
2011-06-01
The gut is an important target organ of injury during critically ill conditions. Although Gram staining is a common and quick method for identifying bacteria, its clinical application has not been fully evaluated in critically ill conditions. This study's aims were to identify patterns of Gram-stained fecal flora and compare them to cultured bacterial counts and to investigate the association between the patterns and septic complications in patients with severe systemic inflammatory response syndrome (SIRS). Fifty-two patients with SIRS were included whose Gram-stained fecal flora was classified into three patterns. In a diverse pattern, large numbers of multiple kinds of bacteria completely covered the field. In a single pattern, one specific kind of bacteria or fungi predominantly covered the field. In a depleted pattern, most bacteria were diminished in the field. In the analysis of fecal flora, the numbers of total obligate anaerobes in the depleted pattern was significantly lower than those in the diverse pattern and single pattern (p Gram-stained fecal flora can be classified into three patterns and are associated with both cultured bacterial counts and clinical information. Gram-stained fecal bacteria can be used as a quick bedside diagnostic marker for severe SIRS patients.
Schöneich, Stefan; Hedwig, Berthold
2012-01-01
The singing behavior of male crickets allows analyzing a central pattern generator (CPG) that was shaped by sexual selection for reliable production of species-specific communication signals. After localizing the essential ganglia for singing in Gryllus bimaculatus, we now studied the calling song CPG at the cellular level. Fictive singing was initiated by pharmacological brain stimulation. The motor pattern underlying syllables and chirps was recorded as alternating spike bursts of wing-opener and wing-closer motoneurons in a truncated wing nerve; it precisely reflected the natural calling song. During fictive singing, we intracellularly recorded and stained interneurons in thoracic and abdominal ganglia and tested their impact on the song pattern by intracellular current injections. We identified three interneurons of the metathoracic and first unfused abdominal ganglion that rhythmically de- and hyperpolarized in phase with the syllable pattern and spiked strictly before the wing-opener motoneurons. Depolarizing current injection in two of these opener interneurons caused additional rhythmic singing activity, which reliably reset the ongoing chirp rhythm. The closely intermeshing arborizations of the singing interneurons revealed the dorsal midline neuropiles of the metathoracic and three most anterior abdominal neuromeres as the anatomical location of singing pattern generation. In the same neuropiles, we also recorded several closer interneurons that rhythmically hyper- and depolarized in the syllable rhythm and spiked strictly before the wing-closer motoneurons. Some of them received pronounced inhibition at the beginning of each chirp. Hyperpolarizing current injection in the dendrite revealed postinhibitory rebound depolarization as one functional mechanism of central pattern generation in singing crickets. PMID:23170234
Effect of plant chemicals on the behavior of the Mediterranean fruit fly
International Nuclear Information System (INIS)
Papadopoulos, N.T.; Kouloussis, N.A.; Katsoyannos, B.I.
2006-01-01
A review of current information on the relation between plant chemicals and the Mediterranean fruit fly is presented. The influence of age and adult physiology on the response of med flies to plant chemicals is studied. The effect of plant chemicals on med fly behavior during host finding, mating and oviposition is analysed. The possible influence of plant chemicals on the dispersion patterns and spatial distribution of the fly is also addressed. (MAC)
Effect of plant chemicals on the behavior of the Mediterranean fruit fly
Energy Technology Data Exchange (ETDEWEB)
Papadopoulos, N.T., E-mail: nikopap@uth.g [University of Thessaly (Greece). Dept. of Crop Production and Rural Environment. Lab. of Entomology and Agricultural Zoology; Kouloussis, N.A.; Katsoyannos, B.I. [University of Thessaloniki, Thessaloniki (Greece). School of Agriculture
2006-07-01
A review of current information on the relation between plant chemicals and the Mediterranean fruit fly is presented. The influence of age and adult physiology on the response of med flies to plant chemicals is studied. The effect of plant chemicals on med fly behavior during host finding, mating and oviposition is analysed. The possible influence of plant chemicals on the dispersion patterns and spatial distribution of the fly is also addressed. (MAC)
Numerical calculation of radiation pattern of plasma channel antenna
International Nuclear Information System (INIS)
Xia Xinren; Yin Chengyou
2010-01-01
The idea of plasma channel antenna (PCA) for high power microwave weapon is presented in this paper. The radiation pattern of PCA is calculated. The directivity functions of general antenna are derived. The near electromagnetic model of PCA is created based on physical circumstances. The electromagnetic fields of PCA and surrounding air in cylindrical coordinate are given. The dispersion equation of PCA is deduced by applying the boundary conditions of electromagnetic fields. The surface wave vector of PCA is achieved. The variations of radiation characteristic with plasma density, antenna length and antenna radius are emphatically discussed. The controllability of PCA's radiation patterns is confirmed. (authors)
Biophysical evaluation of radiofrequency electromagnetic field effects on male reproductive pattern.
Kesari, Kavindra Kumar; Kumar, Sanjay; Nirala, Jayprakash; Siddiqui, Mohd Haris; Behari, Jitendra
2013-03-01
There are possible hazardous health effects of exposure to radiofrequency electromagnetic radiations emitted from mobile phone on the human reproductive pattern. It is more effective while keeping mobile phones in pocket or near testicular organs. Present review examines the possible concern on radio frequency radiation interaction and biological effects such as enzyme induction, and toxicological effects, including genotoxicity and carcinogenicity, testicular cancer, and reproductive outcomes. Testicular infertility or testicular cancer due to mobile phone or microwave radiations suggests an increased level of reactive oxygen species (ROS). Though generation of ROS in testis has been responsible for possible toxic effects on physiology of reproduction, the reviews of last few decades have well established that these radiations are very harmful and cause mutagenic changes in reproductive pattern and leads to infertility. The debate will be focused on bio-interaction mechanism between mobile phone and testicular cancer due to ROS formation. This causes the biological damage and leads to several changes like decreased sperm count, enzymatic and hormonal changes, DNA damage, and apoptosis formation. In the present review, physics of mobile phone including future research on various aspects has been discussed.
Hayes, A. G.; Ewing, R. C.; Cassini Radar Science Team, T.
2011-12-01
Fields of bedform patterns persist across many orders of magnitude, from cm-scale sub-aqueous current ripples to km-scale aeolian dunes, and form with surprisingly little difference in expression despite a range of formative environments. Because of the remarkable similarity between and among patterns, extracting information about climate and environment from these patterns is a challenge. For example, crest orientation is not diagnostic of a particular flow regime; similar patterns form under many different flow configurations. On Titan, these challenges have played out with many attempts to reconcile dune-field patterns with modeled and expected wind regimes. We propose that thinking about the change in dune orientation, rather than the orientation itself, can provide new insights on the long-term stability of the dune-field patterns and the formative wind regime. In this work, we apply the re-orientation model presented by Werner and Kocurek [Geology, 1997] to the equatorial dune fields of Titan. We measure variations in pattern parameters (crest spacing, crest length and defect density, which is the number of defect pairs per total crest length) both within and between Titan's dune fields to describe pattern maturity and identify areas where changes in dune orientation are likely to occur (or may already be occurring). Measured defect densities are similar to Earth's largest linear dune fields, such as the Namib Sand Sea and the Simpson Desert. We use measured defect densities in the Werner and Kocurek model to estimate crestline reorientation rates. We find reorientation timescales varying from ten to a hundred thousand times the average migration timescale (time to migrate a bedform one meter, ~1 Titan year according to Tokano (Aeolian Research, 2010)). Well organized patterns have the longest reorientation time scales (~10^5 migration timescales), while the topographically or spatially isolated patches of dunes show the shortest reorientation times (~10
Research on parallel algorithm for sequential pattern mining
Zhou, Lijuan; Qin, Bai; Wang, Yu; Hao, Zhongxiao
2008-03-01
Sequential pattern mining is the mining of frequent sequences related to time or other orders from the sequence database. Its initial motivation is to discover the laws of customer purchasing in a time section by finding the frequent sequences. In recent years, sequential pattern mining has become an important direction of data mining, and its application field has not been confined to the business database and has extended to new data sources such as Web and advanced science fields such as DNA analysis. The data of sequential pattern mining has characteristics as follows: mass data amount and distributed storage. Most existing sequential pattern mining algorithms haven't considered the above-mentioned characteristics synthetically. According to the traits mentioned above and combining the parallel theory, this paper puts forward a new distributed parallel algorithm SPP(Sequential Pattern Parallel). The algorithm abides by the principal of pattern reduction and utilizes the divide-and-conquer strategy for parallelization. The first parallel task is to construct frequent item sets applying frequent concept and search space partition theory and the second task is to structure frequent sequences using the depth-first search method at each processor. The algorithm only needs to access the database twice and doesn't generate the candidated sequences, which abates the access time and improves the mining efficiency. Based on the random data generation procedure and different information structure designed, this paper simulated the SPP algorithm in a concrete parallel environment and implemented the AprioriAll algorithm. The experiments demonstrate that compared with AprioriAll, the SPP algorithm had excellent speedup factor and efficiency.
Different resistance patterns of reference and field strains of Brucella abortus
Directory of Open Access Journals (Sweden)
Karina L. Miranda
2015-03-01
Full Text Available The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL, fuchsin (20 μg/mL and 80 μg/mL, thionin (2.5 μg/mL and 10 μg/mL, rifampicin (200 μg/mL and safranin O (200 μg/mL. Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL. All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3 all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL. These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.
Patterned Video Sensors For Low Vision
Juday, Richard D.
1996-01-01
Miniature video cameras containing photoreceptors arranged in prescribed non-Cartesian patterns to compensate partly for some visual defects proposed. Cameras, accompanied by (and possibly integrated with) miniature head-mounted video display units restore some visual function in humans whose visual fields reduced by defects like retinitis pigmentosa.
Directory of Open Access Journals (Sweden)
Franz HAAS
2017-12-01
Full Text Available Managers operate in highly different fields. Decision-making can be based on models reflecting in part these differences. The challenge is to connect the respective models without too great a disruption. A threefold procedural approach is proposed by chaining a scheme of modeling in a complex field to an operationalized model to statistical multivariate methods. Multivariate pattern-detecting methods offer the chance to evaluate patterns within the complex field partly. This step completes the cycle of research and improved models can be used in a further cycle.
Fractal patterns of fracture in sandwich composite materials under biaxial tension
Fang, Jing; Yao, Xuefeng; Qi, Jia
1996-04-01
The paper presents a successful experiment to generate a fractal pattern of branching cracks in a brittle material sandwiched in ductile plates. A glass sheet bonded between two polycarbonate plates was heated at different levels of temperatures and the stress field due to the difference of thermal coefficients of the materials was solved by combining the results from isochromatic fringes and thermal stress analysis. At a critical degree of temperature, a crack was initiated at a point and soon produced crack branches to release the stored energy. A tree—like fractal patterns of the branch cracks was then developed with the growth of the branches that subsequently produced more branches on their ways of propagation. The fractal dimension of the fracture pattern was evaluated and the mechanism of the fragmentation was analyzed with the help of the residual stress field of isochromatic and isoclinic patterns.
Patterning of hydrogenated microcrystalline silicon growth by magnetic field
Czech Academy of Sciences Publication Activity Database
Fejfar, Antonín; Stuchlík, Jiří; Mates, Tomáš; Ledinský, Martin; Honda, Shinya; Kočka, Jan
2005-01-01
Roč. 87, č. 1 (2005), 011901/1-011901/3 ISSN 0003-6951 R&D Projects: GA AV ČR(CZ) IAA1010316; GA AV ČR(CZ) IAA1010413; GA ČR(CZ) GD202/05/H003 Institutional research plan: CEZ:AV0Z10100521 Keywords : hydrogenated microcrystalline silicon * magnetic field growth Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.127, year: 2005
International Nuclear Information System (INIS)
Raini, R.K
2002-01-01
Diamond black moth (DBM) Plutella xylostella L. (Lepidoptera: Plutellidae) is the most serious pest of brassica in Kenya. Resistance to chemicals has been reported from various parts of the country. This research investigated brassica and non-brassica crops potential in 'push-pull' strategy toward developing an Integrated Pest Management (IPM) program for DBM in Kenya. The study focused on evaluating the potential influence of selected crops on DBM oviposition, development and infestation on cabbage. Results indicate that DBM preferred to oviposition on brassica crops. No significant differences were observed on DBM development on host plants that supported full development. Minimum development was recorded on non-brassica crop Cleome gynandra, L. In field trials, the mustard, cloeme and coriander intercrops recorded significantly low infestation compared to other intercrops and demonstrated qulities which could be utilized in the development of IPM-option for the DBM
Orthodontics and foetal pathology: a personal view on craniofacial patterning
DEFF Research Database (Denmark)
Kjær, Inger
2009-01-01
This article summarizes the essentials of studies on the craniofacial skeleton performed over 17 years. It presents data from research into foetal pathology resulting in new views on craniofacial patterning and/or fields for further discussion. The fields described cover all areas seen on profile...
Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements
Ren, D.
2015-01-01
Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to