Automatic sex detection of individuals of Ceratitis capitata by means of computer vision in a biofactory

BACKGROUND: The sterile insect technique (SIT) is acknowledged around the world as an effective method for biological pest control of Ceratitis capitata (Wiedemann). Sterile insects are produced in biofactories where one key issue is the selection of the progenitors that have to transmit specific genetic characteristics. Recombinant individuals must be removed as this colony is renewed. Nowadays, this task is performed manually, in a process that is extremely slow, painstaking and labour intensive, in which the sex of individuals must be identified. The paper explores the possibility of using vision sensors and pattern recognition algorithms for automated detection of recombinants. RESULTS: An automatic system is proposed and tested to inspect individual specimens of C. capitata using machine vision. It includes a backlighting system and image processing algorithms for determining the sex of live flies in five high-resolution images of each insect. The system is capable of identifying the sex of the flies by means of a program that analyses the contour of the abdomen, using fast Fourier transform features, to detect the presence of the ovipositor. Moreover, it can find the characteristic spatulate setae of males. Simulation tests with 1000 insects (5000 images) had 100% success in identifying male flies, with an error rate of 0.6% for female flies. CONCLUSION: This work establishes the basis for building a machine for the automatic detection and removal of recombinant individuals in the selection of progenitors for biofactories, which would have huge benefits for SIT around the globe.     

Early investigations into the infection courts used by <Emphasis Type="Italic">Neonectria fuckeliana</Emphasis> to enter <Emphasis Type="Italic">Pinus radiata</Emphasis> stems

Nectria flute canker is a disease of Pinus radiata stems caused by the pathogen Neonectria fuckeliana occurring in the southern parts of New Zealand. In Northern Hemisphere countries where N. fuckeliana is endemic, it is commonly found in Picea and Abies spp. Open wounds, dead attached branches and branch stubs have been identified as the primary infection courts. Although in New Zealand the development of Nectria flute canker disease is associated with pruned branch stubs, recent studies suggest that this is not the only possible entry method as the fungus has been found in trees prior to pruning. Three field trials were established to examine the potential infection mechanisms for N. fuckeliana in P. radiata in New Zealand; including stem wounds and branch stubs. The difference between inoculations into the stem and into branch wood was clear. Inoculation of deep stem wounds resulted in the greatest fluting with 76% of trees inoculated developing cankers. Inoculation directly into stubs resulted in only small stem depressions that occurred in 17% of cases and the fungus was largely contained within the branch trace. Tree response to inoculation with either ascospores or conidia of the Acremonium anamorph gave similar results in terms of canker development and fungal spread within the stem. Tree response to inoculation was highly variable however: in one study 6% of trees did not respond to inoculation at all, while 26% produced severe cankers regardless of inoculation method. A more thorough understanding of the infection mechanisms of N. fuckeliana will contribute to the development of better disease management protocols to prevent infection and disease development in future plantation stock.     

Prevalence of murine norovirus infection in Korean laboratory animal facilities

Currently, murine noroviruses (MNV) are the most prevalent viral pathogens identified in laboratory animal facilities. While several reports exist concerning the prevalence of MNV in North American research facilities, very few reports are available for other parts of the world, including Korea. This study evaluated the prevalence of MNV infection in 745 murine sera collected from 15 animal facilities in Korea by enzyme linked immunosorbent assay (ELISA). Positive cases were subcategorized by murine strain/genetics, housing environments and animal sources. In summary, 6.6% of inbred/outbred mice purchased from commercial vendors were seropositive, 9.6% of in-house colonies were seropositive and 27.0% of genetically modified mice (GMM) were seropositive. Partial gene amplification of fecal isolates from infected animals showed that they were homologous (100%) with MNV-4.     

菲律宾丘陵地土壤保持

丘陵地土壤侵蚀被普遍认为是菲律宾国内最严重的环境问题 ,影响到了土地总面积的 6 3%～ 76 % (Ｐａｎｉｎｇｂａｔａｎ ,1 990 )。近 2 0年来 ,政府和非政府组织已经实施了丘陵地发展项目 ,其中的一个主要组成部分就是改进丘陵地农民使用的土壤保持措施 (如丘陵地农业技术或Ｓ     

Eelgrass slabs, a soilless culture substrate that inhibits adhesion of fungi and oomycetes and enhances antioxidant activity in tomato

Composed of a marine plant, Zostera sp., eelgrass slabs are a novel organic substrate for soilless cultures used in tomato production. The benefit of using eelgrass slabs for growing tomatoes was assessed by comparing it with coconut fiber slabs in regard to contamination by Pythium spp. and to the antioxidant properties of tomato fruits. First, tomato root contamination by Pythium spp. was studied by direct plate counting, and a molecular comparison of fungal and oomycete communities was conducted using PCR-DHPLC. Second, the antioxidant properties of tomato fruits were analyzed by measuring total phenol and carotenoid contents and by evaluating radical scavenging activity. Compared to plants grown on coconut fiber slabs, those on eelgrass slabs presented a lower rate of Pythium spp. root contamination. Moreover, culture on eelgrass slabs produced fruits with better radical scavenging activity and higher total phenol content compared to controls. Carotenoid content was not affected by the type of substrate. This study highlights the value of detrital leaves of Zostera sp. as a substrate for soilless culture that reduces root contamination and also promotes the production of tomato fruits with better nutritional value.     

Patterns of species change in anthropogenically disturbed forests of Madagascar

Five main conclusions arise from this review of the responses of species to anthropogenic disturbance in Madagascar: First, species’ reactions to anthropogenic disturbance are generally negative, but remain poorly known. Our knowledge is patchy among and within higher taxonomic groups; we are still largely gathering case studies. Second, taxonomic groups vary considerably in which proximate factors are most important. Third, several groups show differing responses within different ecoregions. Whether these differences are consistent across groups requires further testing. Fourth, related species often have divergent reactions to disturbance, even within lower taxonomic groupings (families or genera). Thus, we cannot rely on phylogenetic relatedness or even ecological similarity to infer similarity in responses. Finally, disturbance typically reduces species diversity (especially of native and/or endemic species), but also causes species turnover, typically with forest specialists replaced by grassland generalists, and endemics replaced by non-endemics (including invasives). Given these knowledge gaps, we stress the urgency of applied studies that assess species’ ecology, behaviour and health across disturbance gradients, including purely anthropogenic landscapes. Remaining natural vegetation and protected areas will be unable to preserve Madagascar’s biodiversity under the impact of climatic change; we must understand responses of plants and animals to disturbance in order to create buffer zones and corridors combining secondary, degraded and natural habitats.     

Podophyllotoxin and deoxypodophyllotoxin in Juniperus bermudiana and 12 other Juniperus species: optimization of extraction, method validation, and quantification

The lignans podophyllotoxin and deoxypodophyllotoxin are secondary metabolites with potent pharmaceutical applications in cancer therapy. However, the supply of podophyllotoxin from its current natural source, Podophyllum hexandrum, is becoming increasingly problematic, and alternative sources are therefore urgently needed. So far, podophyllotoxin and deoxypodophyllotoxin have been found in some Juniperus species, although at low levels in most cases. Moreover, extraction protocols deserve optimization. This study aimed at developing and validating an efficient extraction protocol of podophyllotoxin and deoxypodophyllotoxin from Juniperus species and applying it to 13 Juniperus species, among which some had never been previously analyzed. Juniperus bermudiana was used for the development and validation of an extraction protocol for podophyllotoxin and deoxypodophyllotoxin allowing extraction yields of up to 22.6 mg/g DW of podophyllotoxin and 4.4 mg/g DW deoxypodophyllotoxin, the highest values found in leaf extract of Juniperus. The optimized extraction protocol and HPLC separation from DAD or MS detections were established and validated to investigate podophyllotoxin and deoxypodophyllotoxin contents in aerial parts of 12 other Juniperus species. This allowed either higher yields to be obtained in some species reported to contain these two compounds or the occurrence of these compounds in some other species to be reported for the first time. This efficient protocol allows effective extraction of podophyllotoxin and deoxypodophyllotoxin from aerial parts of Juniperus species, which could therefore constitute interesting alternative sources of these valuable metabolites.     

Effect of constant versus adjusted commercial fertilizer concentrations on poinsettia 1

Five poinsettia (Euphorbia pulcherrima Willd.), ‘Freedom Red’, ‘Angelika Red’, ‘Nutcracker Red’, ‘Maren’, and ‘Red Splendor’ received the following treatments of a commercial fertilizer based on nitrogen (N) concentrations of: 75 mg L^‐1 to anthesis; 75 mg L^‐1 first 4 weeks then 125 mg L^‐1 to anthesis; 125 mg L^‐1 first 4 weeks then 200 mg L^‐1 to anthesis; and 200 mg L^‐1 to anthesis. Plants were fertigated to appearance of leachate from the bottom of the pot. Treatment concentrations greater than 125/200 and 200 mg.L^‐1 significantly increased plant width of ‘Red Splendor’, height of ‘Nutcracker Red’ and dry weight of ‘Angelika Red’, ‘Nutcracker Red’, and ‘Maren’. Tissue concentrations of N, phosphorus (P), magnesium (Mg), and sulfur (S) increased as fertilizer treatment concentration increased for some cultivars. Significant differences between elemental concentrations of poinsettia cultivars occurred, specifically ‘Nutcracker Red’. Although tissue nutrient concentrations were at or below the critical level, general observations of each cultivar indicated that all plants were of commercial quality and almost indistinguishable between treatments. Poinsettia stem strength was not significantly affected by any fertilizer treatment used in this study.     

An Integration of Water Physicochemistry,Algal Bioassays,Phytoplankton, and Zooplankton for Ecotoxicological Assessment in a Highly Polluted Lowland River

Results of different approaches potentially useful for the evaluation of water ambient quality were analysed and compared in a small temperate lowland river with mixed diffuse and multiple-point source pollution. The Reconquista River (Buenos Aires Province, Argentina), one of the most polluted watercourses of Latin America, receives agrochemicals as well as domestic and industrial (mostly untreated) effluents. Physical and chemical water variables were determined; unispecies algal bioassays (with Chlorella pyrenoidosa and Scenedesmus acutus) were carried out in laboratory; and density and structure of phyto- and zooplankton were analysed at three sites in four dates (representing a range of likely conditions in the river). A general scheme of association among plankton, bioassays and physical/chemical variables was elaborated, that helped to infer possible control factors in this multi-stressed system. Some empirical methods, but mainly mathematical ones including multivariate techniques (as PCA, cluster analysis), were applied for evaluation of samples. A preliminary selection of indices and attributes as potential indicators of the water river quality was made, and then applied for assay a tentative integrative ordination of samples. The relative best water quality was recorded when-where dissolved oxygen concentration, algal diversity and planktonic crustacean density were higher. The worst water quality corresponded to the lack of cladocerans and lowest crustacean density, and higher: organic and industrial pollution, major nutrients (ammonium and orthophosphates), BOD, hardness, conductivity, algal biomass in bioassays, phytoplankton density (>10 000 ind. mL^-1), dominance of a single algal species (>90%), and rotifer proportion in zooplankton (>85%).     

Using linear-bilinear models for studying gene expression × treatment interaction in microarray experiments

In microarray experiments, the global and the specific gene expression in the two-way table of gene x treatments (or tissues) can be studied using linear-bilinear models that incorporate the main effects of genes (G), treatment (T), and gene x treatment interaction (G x T). The plot of the first two axes obtained from the singular value decomposition of the bilinear (multiplicative) term of these models (biplot) facilitates the interpretation of the gene expression patterns. In this study, two microarray datasets were used to illustrate how two linear-bilinear models, the additive main effect and multiplicative interaction (AMMI) and the treatment regression model (TREG) and their biplots can be used to determine the overall gene expression pattern across treatments (or tissues) and for specific treatments. Dataset 1 had 5,339 genes and the objective was to identify genes with modified expression during maize (Zea mays) seed development in response to different parental ploidy levels. In Dataset 2, the aim was to study gene expression in 15 tissue samples with different levels of development of breast cancer when compared with the expression of the genes in noninfected tissues. The results from the analyses of Dataset 1 showed that the biplots of the AMMI and TREG models allow identification of subsets of genes and treatments with noncrossover G x T interaction or with important levels of crossover G x T. Results from Dataset 2 showed that the TREG model and its biplot facilitates the identification of genes with high expression in all tumor cells. Also, the TREG biplots allowed identification of subsets of genes with a low level of gene x tissue crossover interaction.