Local Subspace-Based Outlier Detection using Global Neighbourhoods

Outlier detection in high-dimensional data is a challenging yet important task, as it has applications in, e.g., fraud detection and quality control. State-of-the-art density-based algorithms perform well because they 1) take the local neighbourhoods of data points into account and 2) consider feature subspaces. In highly complex and high-dimensional data, however, existing methods are likely to overlook important outliers because they do not explicitly take into account that the data is often a mixture distribution of multiple components. We therefore introduce GLOSS, an algorithm that performs local subspace outlier detection using global neighbourhoods. Experiments on synthetic data demonstrate that GLOSS more accurately detects local outliers in mixed data than its competitors. Moreover, experiments on real-world data show that our approach identifies relevant outliers overlooked by existing methods, confirming that one should keep an eye on the global perspective even when doing local outlier detection.Comment: Short version accepted at IEEE BigData 201

Resistance risk assessment of the novel complex II inhibitor pyflubumide in the polyphagous pest Tetranychus urticae

Pyflubumide is a novel selective carboxanilide acaricide that inhibits mitochondrial complex II of spider mite species such as Tetranychus urticae. We explored the baseline toxicity and potential cross-resistance risk of pyflubumide in a reference panel of T. urticae strains resistant to various acaricides with different modes of action. A cyenopyrafen-resistant strain (JPR) was identified as the only strain with low-to-moderate level of cross-resistance to pyflubumide (LC50 = 49.07 mg/L). In a resistance risk assessment approach, JPR was subsequently selected which led to two highly resistant strains JPR-R1 (RR = 466.7) and JPR-R2 (RR = 614.8). Interestingly, compared to adult females, resistance was much less pronounced in adult males and eggs of the two JPR-R strains. In order to elucidate resistance mechanisms, we first sequenced the complex II subunits in susceptible and resistant strains, but target-site insensitivity could not be detected. In contrast, synergism/antagonism experiments strongly suggested that cytochrome P450 monooxygenases are involved in pyflubumide resistance. We therefore conducted genome-wide gene expression experiments to investigate constitutive and induced expression patterns and documented the overexpression of five cytochrome P450 and four carboxyl/choline esterase genes in the JPR-R strains after pyflubumide exposure. Together, we provide a first resistance risk assessment of a novel complex II inhibitor and provide first evidence for metabolic resistance mediated by cytochrome P450s in T. urticae

EU ENLARGEMENT TO TURKEY: POTENTIAL IMPACTS ON AGRICULTURAL MARKETS AND HOW THEY ARE SHAPED BY CHANGES IN MACROECONOMIC CONDITIONS

The potential accession of Turkey to the EU, and the related adoption of the CAP by Turkey, is expected to influence agricultural markets in both the EU and Turkey. The extent of the accession impacts depends on the one hand on the way the CAP will be implemented in Turkey, while on the other hand impacts are expected to be also shaped by macroeconomic conditions (like exchange rates, GDP growth and inflation levels). In this paper we provide a comprehensive model-based assessment of the potential impacts on agricultural markets of a Turkish accession to the EU. We first assess the impacts under the assumption of standard macroeconomic projections, then we analyse how a different TL/Euro exchange rate, a doubling of the Turkish inflation rate or a doubling of the Turkish GDP growth rate would influence the accession impacts. Results of the Turkish EU-membership simulation show that the impacts on agricultural markets in Turkey are significant, while effects on EU markets are rather limited. The main impact on Turkish agriculture is a reduction of producer prices. With market prices and produced quantities declining, and as the coupled Turkish direct payments and the input subsidies will be replaced by lower payments of the CAP, agricultural income is expected to be reduced especially for Turkish crop producers (except for tobacco). In contrast, accession effects on the Turkish livestock sector are projected to be positive, mainly due to lower feed costs. Furthermore, the demand levels of most commodities are projected to increase due to lower prices, thus Turkish consumers are expected to gain from an accession to the EU. The further analysis reveals that in particular a depreciation of the Turkish lira alters the results of the accession scenario.Turkey, EU enlargement, agricultural markets, macro economy, AGMEMOD Zusammenfassung, Türkei, EU Erweiterung, Agrarmärkte, Makroökonomie, AGMEMOD, Agribusiness, Agricultural and Food Policy, Agricultural Finance,

The physiology of movement

Movement, from foraging to migration, is known to be under the influence of the environment. The translation of environmental cues to individual movement decision making is determined by an individual's internal state and anticipated to balance costs and benefits. General body condition, metabolic and hormonal physiology mechanistically underpin this internal state. These physiological determinants are tightly, and often genetically linked with each other and hence central to a mechanistic understanding of movement. We here synthesise the available evidence of the physiological drivers and signatures of movement and review (1) how physiological state as measured in its most coarse way by body condition correlates with movement decisions during foraging, migration and dispersal, (2) how hormonal changes underlie changes in these movement strategies and (3) how these can be linked to molecular pathways. We reveale that a high body condition facilitates the efficiency of routine foraging, dispersal and migration. Dispersal decision making is, however, in some cases stimulated by a decreased individual condition. Many of the biotic and abiotic stressors that induce movement initiate a physiological cascade in vertebrates through the production of stress hormones. Movement is therefore associated with hormone levels in vertebrates but also insects, often in interaction with factors related to body or social condition. The underlying molecular and physiological mechanisms are currently studied in few model species, and show -in congruence with our insights on the role of body condition- a central role of energy metabolism during glycolysis, and the coupling with timing processes during migration. Molecular insights into the physiological basis of movement remain, however, highly refractory. We finalise this review with a critical reflection on the importance of these physiological feedbacks for a better mechanistic understanding of movement and its effects on ecological dynamics at all levels of biological organization

ICT, Innovation and Business Performance in Services: Evidence for Germany and the Netherlands

Using panel data for German and Dutch firms from the services sector, this paper analyses the importance of ICT capital deepening and innovation for productivity. We employ a model that takes into account that innovation and ICT use may be complementary. The results show that the contribution of ICT capital deepening is raised when firms combine ICT use and technological innovations on a more permanent basis. Moreover, the joint impact of ICT use and permanent technological innovation on productivity appears to be of the same order of magnitude in the two countries. However, the direct impacts of innovation on multi-factor productivity seems to be more robust for Germany than for the Netherlands. --Productivity,Information and Communication Technologies,Innovation,Services,Panel Data

Targeted mutagenesis using CRISPR-Cas9 in the chelicerate herbivore Tetranychus urticae

The use of CRISPR-Cas9 has revolutionized functional genetic work in many organisms, including more and more insect species. However, successful gene editing or genetic transformation has not yet been reported for chelicerates, the second largest group of terrestrial animals. Within this group, some mite and tick species are economically very important for agriculture and human health, and the availability of a gene-editing tool would be a significant advancement for the field. Here, we report on the use of CRISPR-Cas9 in the spider mite Tetranychus urticae. The ovary of virgin adult females was injected with a mix of Cas9 and sgRNAs targeting the phytoene desaturase gene. Natural mutants of this laterally transferred gene have previously shown an easy-to-score albino phenotype. Albino sons of injected virgin females were mated with wild-type females, and two independent transformed lines where created and further characterized. Albinism inherited as a recessive monogenic trait. Sequencing of the complete target-gene of both lines revealed two different lesions at expected locations near the PAM site in the target-gene. Both lines did not genetically complement each other in dedicated crosses, nor when crossed to a reference albino strain with a known genetic defect in the same gene. In conclusion, two independent mutagenesis events were induced in the spider mite T. urticae using CRISPR-Cas9, hereby providing proof-of-concept that CRISPR-Cas9 can be used to create gene knockouts in mites

Analysis of the olive fruit fly Bactrocera oleae transcriptome and phylogenetic classification of the major detoxification gene families

he olive fruit fly Bactrocera oleae has a unique ability to cope with olive flesh, and is the most destructive pest of olives worldwide. Its control has been largely based on the use of chemical insecticides, however, the selection of insecticide resistance against several insecticides has evolved. The study of detoxification mechanisms, which allow the olive fruit fly to defend against insecticides, and/or phytotoxins possibly present in the mesocarp, has been hampered by the lack of genomic information in this species. In the NCBI database less than 1,000 nucleotide sequences have been deposited, with less than 10 detoxification gene homologues in total. We used 454 pyrosequencing to produce, for the first time, a large transcriptome dataset for B. oleae. A total of 482,790 reads were assembled into 14,204 contigs. More than 60% of those contigs (8,630) were larger than 500 base pairs, and almost half of them matched with genes of the order of the Diptera. Analysis of the Gene Ontology (GO) distribution of unique contigs, suggests that, compared to other insects, the assembly is broadly representative for the B. oleae transcriptome. Furthermore, the transcriptome was found to contain 55 P450, 43 GST-, 15 CCE- and 18 ABC transporter-genes. Several of those detoxification genes, may putatively be involved in the ability of the olive fruit fly to deal with xenobiotics, such as plant phytotoxins and insecticides. In summary, our study has generated new data and genomic resources, which will substantially facilitate molecular studies in B. oleae, including elucidation of detoxification mechanisms of xenobiotic, as well as other important aspects of olive fruit fly biology

Feeding history affects intraguild interactions between Harmonia axyridis (Coleoptera: Coccinellidae) and Episyrphus balteatus (Diptera: Syrphidae)

While the effect of several factors such as predator and prey size, morphology and developmental stage on intraguild predation (IGP) is widely investigated, little is known about the influence of diet on the occurrence and outcome of IGP. In the present study, the effect of the diet experienced during larval development on IGP between the ladybird Harmonia axyridis and the syrphid Episyrphus balteatus is investigated. Four diets were tested for H. axyridis: eggs of the Mediterranean flour moth Ephestia kuehniella, pea aphids, Acyrthosiphon pisum, in an ad libitum amount, pea aphids in a limited amount, and honey bee pollen. For E. balteatus only the two aphid diets were tested. First, experiments were performed to determine the quality of the various diets for development of both predators. Second, IGP experiments between H. axyridis and E. balteatus were performed both in Petri dishes and on potted pepper plants. The diet of both species influenced the incidence of IGP between H. axyridis and E. balteatus both in Petri dishes and on potted plants. In general, smaller larvae of H. axyridis (those fed on poor or restricted diet) fed more on hoverflies than large (wellnourished) ladybird larvae. Further, poorly nourished (smaller) larvae of E. balteatus were more susceptible to predation than well-fed (larger) hoverfly larvae. The observed effects were not only due to the lower fitness of larvae of both predators reared on an inferior quality diet but also to changes in predator behaviour. The results from this study show that IGP interactions are influenced by a multitude of factors, including feeding history of the organisms involved, and emphasize the importance of taking these factors into account in order to fully understand the ecological relevance of IGP

Why do herbivorous mites suppress plant defenses?

Plants have evolved numerous defensive traits that enable them to resist herbivores. In turn, this resistance has selected for herbivores that can cope with defenses by either avoiding, resisting or suppressing them. Several species of herbivorous mites, such as the spider mites Tetranychus urticae and Tetranychus evansi, were found to maximize their performance by suppressing inducible plant defenses. At first glimpse it seems obvious why such a trait will be favored by natural selection. However, defense suppression appeared to readily backfire since mites that do so also make their host plant more suitable for competitors and their offspring more attractive for natural enemies. This, together with the fact that spider mites are infamous for their ability to resist (plant) toxins directly, justifies the question as to why traits that allow mites to suppress defenses nonetheless seem to be relatively common? We argue that this trait may facilitate generalist herbivores, like T. urticae, to colonize new host species. While specific detoxification mechanisms may, on average, be suitable only on a narrow range of similar hosts, defense suppression may be more broadly effective, provided it operates by targeting conserved plant signaling components. If so, resistance and suppression may be under frequency-dependent selection and be maintained as a polymorphism in generalist mite populations. In that case, the defense suppression trait may be under rapid positive selection in subpopulations that have recently colonized a new host but may erode in relatively isolated populations in which host-specific detoxification mechanisms emerge. Although there is empirical evidence to support these scenarios, it contradicts the observation that several of the mite species found to suppress plant defenses actually are relatively specialized. We argue that in these cases buffering traits may enable such mites to mitigate the negative side effects of suppression in natural communities and thus shield this trait from natural selection