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https://www.readbyqxmd.com/read/28431346/caged-gammarus-as-biomonitors-identifying-thresholds-of-toxic-metal-bioavailability-that-affect-gammarid-densities-at-the-french-national-scale
#1
Alexandre Ciliberti, Arnaud Chaumot, Rémi Recoura-Massaquant, André Chandesris, Adeline François, Marina Coquery, Martial Ferréol, Olivier Geffard
Bioaccumulated concentrations of toxic elements in biomonitor invertebrate species have already been used to successfully link metal bioavailability and impairments of stream macroinvertebrate communities at the scale of the watershed. However, implementing this empirical comparative approach at a greater spatial scale remains a challenge due to the diversity of biogeographical contexts encompassed by regional and national scales. We showed in previous studies that the use of standard organisms caged permits the use of a common biomonitor over a far greater geographical range, while limiting the influence of confounding factors on levels of bioavailable contamination...
April 17, 2017: Water Research
https://www.readbyqxmd.com/read/28430279/microcontact-printing-with-aminosilanes-creating-biomolecule-micro-and-nanoarrays-for-multiplexed-microfluidic-bioassays
#2
Shivani Sathish, Sébastien G Ricoult, Kazumi Toda-Peters, Amy Q Shen
Microfluidic systems integrated with protein and DNA micro- and nanoarrays have been the most sought-after technologies to satisfy the growing demand for high-throughput disease diagnostics. As the sensitivity of these systems relies on the bio-functionalities of the patterned recognition biomolecules, the primary concern has been to develop simple technologies that enable biomolecule immobilization within microfluidic devices whilst preserving bio-functionalities. To address this concern, we introduce a two-step patterning approach to create micro- and nanoarrays of biomolecules within microfluidic devices...
April 21, 2017: Analyst
https://www.readbyqxmd.com/read/28429586/bubble-mediated-ultrasensitive-multiplex-detection-of-metal-ions-in-three-dimensional-dna-nanostructure-encoded-microchannels
#3
Xiangmeng Qu, Fan Yang, Hong Chen, Jiang Li, Hongbo Zhang, Guo-Jun Zhang, Li Li, Lihua Wang, Shiping Song, Yang Tian, Hao Pei
The development of rapid and sensitive point-of-test devices for the on-site monitoring of heavy-metal contamination has great scientific and technological importance. However, developing fast, inexpensive, and sensitive microarray sensors to achieve such goal remains challenging. In this work, we present a DNA nanostructured microarray (DNM) with tubular three-dimensional (3D) sensing surface and ordered nanotopography. This microarray enables enhanced molecular interaction toward the rapid and sensitive multiplex detection of heavy-metal ions...
April 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28429183/label-free-okadaic-acid-detection-using-growth-of-gold-nanoparticles-in-sensor-gaps-as-a-conductive-tag
#4
Yuxiang Pan, Zijian Wan, Longjie Zhong, Xueqin Li, Qi Wu, Jun Wang, Ping Wang
Okadaic acid (OA) is a marine toxin ingested by shellfish. In this work, a simple, sensitive and label-free gap-based electrical competitive bioassay has been developed for this biotoxin detection. The gap-electrical biosensor is constructed by modifying interdigitated microelectrodes with gold nanoparticles (AuNPs) and using the self-catalytic growth of AuNPs as conductive bridges. In this development, the AuNPs growth is realized in the solution of glucose and chloroauric acid, with glucose oxidation used as the catalysis for growth of the AuNPs...
June 2017: Biomedical Microdevices
https://www.readbyqxmd.com/read/28428873/a-maize-landrace-that-emits-defense-volatiles-in-response-to%C3%A2-herbivore-eggs-possesses-a-strongly-inducible-terpene-synthase-gene
#5
Amanuel Tamiru, Toby J A Bruce, Annett Richter, Christine M Woodcock, Charles A O Midega, Jörg Degenhardt, Segenet Kelemu, John A Pickett, Zeyaur R Khan
Maize (Zea mays) emits volatile terpenes in response to insect feeding and egg deposition to defend itself against harmful pests. However, maize cultivars differ strongly in their ability to produce the defense signal. To further understand the agroecological role and underlying genetic mechanisms for variation in terpene emission among maize cultivars, we studied the production of an important signaling component (E)-caryophyllene in a South American maize landrace Braz1006 possessing stemborer Chilo partellus egg inducible defense trait, in comparison with the European maize line Delprim and North American inbred line B73...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28428863/switching-among-natal-and-auxiliary-hosts-increases-vulnerability-of-spodoptera-exigua-h%C3%A3-bner-lepidoptera-noctuidae-to-insecticides
#6
Qamar Saeed, Shafqat Saeed, Faheem Ahmad
The role of insecticidal application and host plant resistance in managing Spodoptera exigua has been well documented, but the effect of different host plants, on which the pest cycles its population in the field, has seldom been investigated. Therefore, we have studied the vulnerability of S. exigua against commonly used insecticides (cypermethrin, chlorpyrifos, lufenuron, and emamectin benzoate) with different mode of actions when it switches its generations from natal to auxiliary hosts and vice versa. Different field populations being established on different host plants including castor, cauliflower, cotton, okra, and spinach were collected and reared in the laboratory before insecticidal bioassays...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28427447/benchmarking-insecticide-resistance-intensity-bioassays-for-anopheles-malaria-vector-species-against-resistance-phenotypes-of-known-epidemiological-significance
#7
Nelius Venter, Shȕné V Oliver, Mbanga Muleba, Craig Davies, Richard H Hunt, Lizette L Koekemoer, Maureen Coetzee, Basil D Brooke
BACKGROUND: Insecticide use via indoor residual spraying (IRS) or treated nets is the primary method for controlling malaria vector populations. The incidence of insecticide resistance in vector populations is burgeoning globally making resistance management key to the design of effective malaria control and elimination strategies. Vector populations can be assessed for insecticide resistance using a binary (susceptible or resistant) classification based on the use of the standard WHO insecticide susceptibility assay for adult anopheline mosquitoes...
April 20, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28426679/control-of-zoonotic-cutaneous-leishmaniasis-vector-phlebotomus-papatasi-using-attractive-toxic-sugar-baits-atsb
#8
Abedin Saghafipour, Hassan Vatandoost, Ali Reza Zahraei-Ramazani, Mohammad Reza Yaghoobi-Ershadi, Yavar Rassi, Moharram Karami Jooshin, Mohammad Reza Shirzadi, Amir Ahmad Akhavan
INTRODUCTION: Attractive Toxic Sugar Baits (ATSB) is a new vector control method that meets Integrated Vector Management (IVM) goals. In an experimental design, this study aimed to determine effects of ATSB on control of Phlebotomus papatasi, as a main vector of Zoonotic Cutaneous Leishmaniasis (ZCL), in Qom Province, center of Iran. METHODS: In a cross-sectional design, boric acid was mixed with brown sugar solution and tested as toxic baits for P. papatasi. Two methods were utilized to use the baits: (a) spraying ATSB on vegetation, bushes, and shrubs; and (b) setting ATSB-treated barrier fences in front of colonies at 500 m distance from the houses in outskirts of villages...
2017: PloS One
https://www.readbyqxmd.com/read/28426411/toxoplasma-gondii-in-backyard-pigs-seroepidemiology-and-mouse-bioassay
#9
Erika Fernanda Torres Samico-Fernandes, Marcela Fernanda Torres Samico-Fernandes, Pedro Paulo Feitosa de Albuquerque, Jonatas Campos de Almeida, André de Souza Santos, André da Rocha Mota, Orestes Luiz de Souza Neto, Rinaldo Aparecido Mota
The aim of this study was to evaluate the occurrence of Toxoplasma gondii in backyard pigs destined for human consumption in Pernambuco state, Brazil. Blood and tissue samples (liver, heart, brain, lung and diaphragm) were collected from 224 pigs from legal slaughterhouses and tested for T. gondii infection. Antibodies to T. gondii were found in the sera of 37.9% (85/224) by using the immunofluorescence antibody test (cut-off - 1:64). Tissue samples from seropositive pigs were bioassayed in mice. Tissue samples from seropositive pigs and from mice of the bioassay were submitted to histopathology, immunohistochemistry, polymerase chain reaction (PCR) and sequencing; 14...
June 1, 2017: Acta Parasitologica
https://www.readbyqxmd.com/read/28424845/the-regulatory-role-of-the-transcription-factor-crz1-in-stress-tolerance-pathogenicity-and-its-target-gene-expression-in-metarhizium-acridum
#10
Xing Chen, Yuanze Liu, Nemat O Keyhani, Yuxian Xia, Yueqing Cao
In fungi, the Ca(2+)/calcineurin signaling pathway is critical in mediating growth, morphology, stress responses, and pathogenicity. Crz1 is a calcineurin-responsive zinc finger transcription factor. Here, MaCrz1 was identified and functionally characterized in the entomopathogenic fungus Metarhizium acridum by characterization of a targeted gene knockout strain. Conidia of the ΔMacrz1 mutant were aberrant in cell surface features and lacked the characteristic hydrophobic rodlet layer, and the mutant displayed increased sensitivity to oxidative stress, cell wall perturbing agents, heat stress, and ultraviolet irradiation as compared to the wild-type and complemented strains...
April 19, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28424463/luciferase-specific-coelenterazine-analogues-for-optical-contamination-free-bioassays
#11
Ryo Nishihara, Masahiro Abe, Shigeru Nishiyama, Daniel Citterio, Koji Suzuki, Sung Bae Kim
Spectral overlaps among the multiple optical readouts commonly cause optical contamination in fluorescence and bioluminescence. To tackle this issue, we created five-different lineages of coelenterazine (CTZ) analogues designed to selectively illuminate a specific luciferase with unique luciferase selectivity. In the attempt, we found that CTZ analogues with ethynyl or styryl groups display dramatically biased bioluminescence to specific luciferases and pHs by modifying the functional groups at the C-2 and C-6 positions of the imidazopyradinone backbone of CTZ...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28423427/influence-of-temperature-and-relative-humidity-on-the-insecticidal-efficacy-of-metarhizium-anisopliae-against-larvae-of-ephestia-kuehniella-lepidoptera-pyralidae-on-wheat
#12
Christos G Athanassiou, Nickolas G Kavallieratos, Christos I Rumbos, Demetrius C Kontodimas
A series of laboratory bioassays were conducted for the evaluation of the insecticidal efficacy of an isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) against larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under various temperature-relative humidity (r.h.) conditions. The fungus was applied at four doses (0, 8 × 106, 8 × 108, and 8 × 1010 conidia ml-1) on wheat and insect mortality was assessed after exposure of 1, 2, 7, and 14 d...
January 1, 2017: Journal of Insect Science
https://www.readbyqxmd.com/read/28423093/short-and-long-term-evaluation-of-the-efficiency-of-permanet%C3%A2-2-0-bed-net-against-environmental-factors-and-washing-using-bioassay-tests
#13
Mohammad Hassan Kayedi, Kiumars Khamisabadi, Ali Akbar Haghdoost, Zohreh Kayedi, Shirzad Fallahi, Nargess Abdali
The aim of the present study was to examine the resistance of PermaNet® 2.0 bed nets against repeated washing and environmental factors by using bioassay tests. After 5, 15 and 21 washings with detergents and by using bioassay tests, the resistance of 40 PermaNet® 2.0 bed nets was compared with that of 40 bed nets conventionally treated with one K-O tablet. To examine the long-term resistance, 31 PermaNet® 2.0 bed nets were also distributed among villagers, and were re-collected to perform bioassay tests after 1, 2 and 5 years...
April 13, 2017: Revista do Instituto de Medicina Tropical de São Paulo
https://www.readbyqxmd.com/read/28422495/cochliotoxin-a-dihydropyranopyran-4-5-dione-and-its-analogues-produced-by-cochliobolus-australiensis-display-phytotoxic-activity-against-buffelgrass-cenchrus-ciliaris
#14
Marco Masi, Susan Meyer, Suzette Clement, Alessio Cimmino, Massimo Cristofaro, Antonio Evidente
Buffelgrass (Pennisetum ciliare or Cenchrus ciliaris) is a perennial grass that has become highly invasive in the Sonoran Desert of southern Arizona. In the search for novel control strategies against this weed, strains of the foliar fungal pathogen Cochliobolus australiensis from buffelgrass have been screened for their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides in an integrated pest management strategy. A new phytotoxin, named cochliotoxin, was isolated from liquid culture of this fungus together with radicinin, radicinol, and their 3-epimers...
April 19, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28421401/liquid-marbles-as-bioreactors-for-the-study-of-three-dimensional-cell-interactions
#15
Raja K Vadivelu, Harshad Kamble, Ahmed Munaz, Nam-Trung Nguyen
Liquid marble as a bioreactor platform for cell-based studies has received significant attention, especially for developing 3D cell-based assays. This platform is particularly suitable for 3D in-vitro modeling of cell-cell interactions. For the first time, we demonstrated the interaction of olfactory ensheathing cells (OECs) with nerve debris and meningeal fibroblast using liquid marbles. As the transplantation of OECs can be used for repairing nerve injury, degenerating cell debris within the transplantation site can adversely affect the survival of transplanted OECs...
June 2017: Biomedical Microdevices
https://www.readbyqxmd.com/read/28421311/long-term-soil-alteration-in-historical-charcoal-hearths-affects-tuber-melanosporum-mycorrhizal-development-and-environmental-conditions-for-fruiting
#16
Sergi Garcia-Barreda, Sara Molina-Grau, Ricardo Forcadell, Sergio Sánchez, Santiago Reyna
Abandoned charcoal hearths constitute a very particular habitat for spontaneous fruiting of Tuber melanosporum, leading some harvesters to hypothesise that the fungus could benefit from the alterations that these soils underwent. However, ecological mechanisms involved in this relation are not fully elucidated yet. As a first step to understand it, the influence of long-term soil alteration on the symbiotic stage of T. melanosporum and on selected soil properties considered key to fruiting was assessed by conducting a greenhouse bioassay and a field observational study...
April 18, 2017: Mycorrhiza
https://www.readbyqxmd.com/read/28421085/expression-of-arabidopsis-shn1-in-indian-mulberry-morus-indica-l-increases-leaf-surface-wax-content-and-reduces-post-harvest-water-loss
#17
R S Sajeevan, Karaba N Nataraja, K S Shivashankara, N Pallavi, D S Gurumurthy, M B Shivanna
Mulberry (Morus species) leaf is the sole food for monophagous silkworms, Bombyx mori L. Abiotic stresses such as drought, salinity, and high temperature, significantly decrease mulberry productivity and post-harvest water loss from leaves influence silkworm growth and cocoon yield. Leaf surface properties regulate direct water loss through the cuticular layer. Leaf surface waxes, contribute for cuticular resistance and protect mesophyll cells from desiccation. In this study we attempted to overexpress AtSHN1, a transcription factor associated with epicuticular wax biosynthesis to increase leaf surface wax load in mulberry...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28417946/essential-oils-of-hyptis-pectinata-chemotypes-isolation-binary-mixtures-and-acute-toxicity-on-leaf-cutting-ants
#18
Rosana B Feitosa-Alcantara, Leandro Bacci, Arie F Blank, Péricles B Alves, Indira Morgana de A Silva, Caroline A Soares, Taís S Sampaio, Paulo Cesar de L Nogueira, Maria de Fátima Arrigoni-Blank
Leaf-cutting ants are pests of great economic importance due to the damage they cause to agricultural and forest crops. The use of organosynthetic insecticides is the main form of control of these insects. In order to develop safer technology, the objective of this work was to evaluate the formicidal activity of the essential oils of two Hyptis pectinata genotypes (chemotypes) and their major compounds on the leaf-cutting ants Acromyrmex balzani Emery and Atta sexdens rubropilosa Forel. Bioassays of exposure pathways (contact and fumigation) and binary mixtures of the major compounds were performed...
April 12, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28416644/evaluation-of-different-estimation-methods-for-accuracy-and-precision-in-biological-assay-validation
#19
Binbing Yu, Harry Yang
Biological assays (bioassays) are procedures to estimate the potency of a substance by studying its effects on living organisms, tissues, and cells. Bioassays are essential tools for gaining insight into biologic systems and processes including, for example, the development of new drugs and monitoring environmental pollutants. Two of the most important parameters of bioassay performance are relative accuracy (bias) and precision. Although general strategies and formulas are provided in USP 〈1033〉, a comprehensive understanding of the definitions of bias and precision remain elusive...
April 17, 2017: PDA Journal of Pharmaceutical Science and Technology
https://www.readbyqxmd.com/read/28414744/knockdown-resistance-mutations-predict-ddt-resistance-and-pyrethroid-tolerance-in-the-visceral-leishmaniasis-vector-phlebotomus-argentipes
#20
Bruno Gomes, Bidyut Purkait, Rinki Michelle Deb, Aarti Rama, Rudra Pratap Singh, Geraldine Marie Foster, Michael Coleman, Vijay Kumar, Mark Paine, Pradeep Das, David Weetman
BACKGROUND: Indoor residual spraying (IRS) with DDT has been the primary strategy for control of the visceral leishmaniasis (VL) vector Phlebotomus argentipes in India but efficacy may be compromised by resistance. Synthetic pyrethroids are now being introduced for IRS, but with a shared target site, the para voltage-gated sodium channel (VGSC), mutations affecting both insecticide classes could provide cross-resistance and represent a threat to sustainable IRS-based disease control. METHODOLOGY/PRINCIPAL FINDINGS: A region of the Vgsc gene was sequenced in P...
April 17, 2017: PLoS Neglected Tropical Diseases
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