The Time Course of Segmentation and Cue-Selectivity in the Human Visual Cortex

Texture discontinuities are a fundamental cue by which the visual system segments objects from their background. The neural mechanisms supporting texture-based segmentation are therefore critical to visual perception and cognition. In the present experiment we employ an EEG source-imaging approach in order to study the time course of texture-based segmentation in the human brain. Visual Evoked Potentials were recorded to four types of stimuli in which periodic temporal modulation of a central 3° figure region could either support figure-ground segmentation, or have identical local texture modulations but not produce changes in global image segmentation. The image discontinuities were defined either by orientation or phase differences across image regions. Evoked responses to these four stimuli were analyzed both at the scalp and on the cortical surface in retinotopic and functional regions-of-interest (ROIs) defined separately using fMRI on a subject-by-subject basis. Texture segmentation (tsVEP: segmenting versus non-segmenting) and cue-specific (csVEP: orientation versus phase) responses exhibited distinctive patterns of activity. Alternations between uniform and segmented images produced highly asymmetric responses that were larger after transitions from the uniform to the segmented state. Texture modulations that signaled the appearance of a figure evoked a pattern of increased activity starting at ∼143 ms that was larger in V1 and LOC ROIs, relative to identical modulations that didn't signal figure-ground segmentation. This segmentation-related activity occurred after an initial response phase that did not depend on the global segmentation structure of the image. The two cue types evoked similar tsVEPs up to 230 ms when they differed in the V4 and LOC ROIs. The evolution of the response proceeded largely in the feed-forward direction, with only weak evidence for feedback-related activity

Bats in the anthropogenic matrix: Challenges and opportunities for the conservation of chiroptera and their ecosystem services in agricultural landscapes

Intensification in land-use and farming practices has had largely negative effects on bats, leading to population declines and concomitant losses of ecosystem services. Current trends in land-use change suggest that agricultural areas will further expand, while production systems may either experience further intensification (particularly in developing nations) or become more environmentally friendly (especially in Europe). In this chapter, we review the existing literature on how agricultural management affects the bat assemblages and the behavior of individual bat species, as well as the literature on provision of ecosystem services by bats (pest insect suppression and pollination) in agricultural systems. Bats show highly variable responses to habitat conversion, with no significant change in species richness or measures of activity or abundance. In contrast, intensification within agricultural systems (i.e., increased agrochemical inputs, reduction of natural structuring elements such as hedges, woods, and marshes) had more consistently negative effects on abundance and species richness. Agroforestry systems appear to mitigate negative consequences of habitat conversion and intensification, often having higher abundances and activity levels than natural areas. Across biomes, bats play key roles in limiting populations of arthropods by consuming various agricultural pests. In tropical areas, bats are key pollinators of several commercial fruit species. However, these substantial benefits may go unrecognized by farmers, who sometimes associate bats with ecosystem disservices such as crop raiding. Given the importance of bats for global food production, future agricultural management should focus on “wildlife-friendly” farming practices that allow more bats to exploit and persist in the anthropogenic matrix so as to enhance provision of ecosystem services. Pressing research topics include (1) a better understanding of how local-level versus landscape-level management practices interact to structure bat assemblages, (2) the effects of new pesticide classes and GM crops on bat populations, and (3) how increased documentation and valuation of the ecosystem services provided by bats could improve attitudes of producers toward their conservation

25th Annual Computational Neuroscience Meeting: CNS-2016

Abstracts of the 25th Annual Computational Neuroscience Meeting: CNS-2016 Seogwipo City, Jeju-do, South Korea. 2–7 July 201

Monitoring priority waste streams, data 1994

The results of the monitoring programme on priority waste streams in the Netherlands are presented for the year 1994. Basic data and additional information on the quantities, specified into origin and method of disposal, as well as on the composition, are presented in a standard format for 26 priority waste streams. The procedures and sources of information used to determine the data have been described in measuring protocols. Furthermore a survey of the amounts per method of disposal for the years 1993 and 1994 is given.De resultaten van het monitoringprogramma voor prioritaire afvalstoffen zijn weergegeven voor 1994. In het rapport zijn de rapportages van 26 prioritaire afvalstoffen gebundeld. Per afvalstof worden de belangrijkste gegevens betreffende de hoeveelheden (onder meer naar herkomst en verwerkingsmethode) en samenstelling volgens een standaard opzet gepresenteerd en toegelicht. De gegevens zijn vastgesteld op basis van een werkwijze en met behulp van bronnen die beschreven zijn in meetprotocollen. Verder bevat het rapport een overzichtstabel waarin voor de prioritaire afvalstoffen de hoeveelheden per verwerkingsmethode voor 1993 en 1994 zijn weergegeven. Het blijkt dat ten opzichte van 1993 geen grote veranderingen vastgesteld kunnen worden in het aanbod van afval. Wel is sprake van meer hergebruik en minder storten van afval

Monitoring priority waste streams, data 1994

De resultaten van het monitoringprogramma voor prioritaire afvalstoffen zijn weergegeven voor 1994. In het rapport zijn de rapportages van 26 prioritaire afvalstoffen gebundeld. Per afvalstof worden de belangrijkste gegevens betreffende de hoeveelheden (onder meer naar herkomst en verwerkingsmethode) en samenstelling volgens een standaard opzet gepresenteerd en toegelicht. De gegevens zijn vastgesteld op basis van een werkwijze en met behulp van bronnen die beschreven zijn in meetprotocollen. Verder bevat het rapport een overzichtstabel waarin voor de prioritaire afvalstoffen de hoeveelheden per verwerkingsmethode voor 1993 en 1994 zijn weergegeven. Het blijkt dat ten opzichte van 1993 geen grote veranderingen vastgesteld kunnen worden in het aanbod van afval. Wel is sprake van meer hergebruik en minder storten van afval.The results of the monitoring programme on priority waste streams in the Netherlands are presented for the year 1994. Basic data and additional information on the quantities, specified into origin and method of disposal, as well as on the composition, are presented in a standard format for 26 priority waste streams. The procedures and sources of information used to determine the data have been described in measuring protocols. Furthermore a survey of the amounts per method of disposal for the years 1993 and 1994 is given.DGM/