Motmot, an open-source toolkit for realtime video acquisition and analysis

<p>Abstract</p> <p>Background</p> <p>Video cameras sense passively from a distance, offer a rich information stream, and provide intuitively meaningful raw data. Camera-based imaging has thus proven critical for many advances in neuroscience and biology, with applications ranging from cellular imaging of fluorescent dyes to tracking of whole-animal behavior at ecologically relevant spatial scales.</p> <p>Results</p> <p>Here we present 'Motmot': an open-source software suite for acquiring, displaying, saving, and analyzing digital video in real-time. At the highest level, Motmot is written in the Python computer language. The large amounts of data produced by digital cameras are handled by low-level, optimized functions, usually written in C. This high-level/low-level partitioning and use of select external libraries allow Motmot, with only modest complexity, to perform well as a core technology for many high-performance imaging tasks. In its current form, Motmot allows for: (1) image acquisition from a variety of camera interfaces (package motmot.cam_iface), (2) the display of these images with minimal latency and computer resources using wxPython and OpenGL (package motmot.wxglvideo), (3) saving images with no compression in a single-pass, low-CPU-use format (package motmot.FlyMovieFormat), (4) a pluggable framework for custom analysis of images in realtime and (5) firmware for an inexpensive USB device to synchronize image acquisition across multiple cameras, with analog input, or with other hardware devices (package motmot.fview_ext_trig). These capabilities are brought together in a graphical user interface, called 'FView', allowing an end user to easily view and save digital video without writing any code. One plugin for FView, 'FlyTrax', which tracks the movement of fruit flies in real-time, is included with Motmot, and is described to illustrate the capabilities of FView.</p> <p>Conclusion</p> <p>Motmot enables realtime image processing and display using the Python computer language. In addition to the provided complete applications, the architecture allows the user to write relatively simple plugins, which can accomplish a variety of computer vision tasks and be integrated within larger software systems. The software is available at <url>http://code.astraw.com/projects/motmot</url></p

Modelling Drosophila motion vision pathways for decoding the direction of translating objects against cluttered moving backgrounds

Decoding the direction of translating objects in front of cluttered moving backgrounds, accurately and efficiently, is still a challenging problem. In nature, lightweight and low-powered flying insects apply motion vision to detect a moving target in highly variable environments during flight, which are excellent paradigms to learn motion perception strategies. This paper investigates the fruit fly Drosophila motion vision pathways and presents computational modelling based on cuttingedge physiological researches. The proposed visual system model features bio-plausible ON and OFF pathways, wide-field horizontal-sensitive (HS) and vertical-sensitive (VS) systems. The main contributions of this research are on two aspects: (1) the proposed model articulates the forming of both direction-selective and direction-opponent responses, revealed as principalfeaturesofmotionperceptionneuralcircuits,inafeed-forwardmanner;(2)italsoshowsrobustdirectionselectivity to translating objects in front of cluttered moving backgrounds, via the modelling of spatiotemporal dynamics including combination of motion pre-filtering mechanisms and ensembles of local correlators inside both the ON and OFF pathways, which works effectively to suppress irrelevant background motion or distractors, and to improve the dynamic response. Accordingly, the direction of translating objects is decoded as global responses of both the HS and VS systems with positive ornegativeoutputindicatingpreferred-direction or null-direction translation.The experiments have verified the effectiveness of the proposed neural system model, and demonstrated its responsive preference to faster-moving, higher-contrast and larger-size targets embedded in cluttered moving backgrounds

Effects and feasibility of a standardised orientation and mobility training in using an identification cane for older adults with low vision: design of a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Orientation and mobility training (O&M-training) in using an identification cane, also called symbol cane, is provided to people with low vision to facilitate independent participation in the community. In The Netherlands this training is mainly practice-based because a standardised and validly evaluated O&M-training in using the identification cane is lacking. Recently a standardised O&M-training in using the identification cane was developed. This training consists of two face-to-face sessions and one telephone session during which, in addition to usual care, the client's needs regarding mobility are prioritised, and cognitive restructuring techniques, action planning and contracting are applied to facilitate the use of the cane. This paper presents the design of a randomised controlled trial aimed to evaluate this standardised O&M-training in using the identification cane in older adults with low vision.</p> <p>Methods/design</p> <p>A parallel group randomised controlled trial was designed to compare the standardised O&M-training with usual care, i.e. the O&M-training commonly provided by the mobility trainer. Community-dwelling older people who ask for support at a rehabilitation centre for people with visual impairment and who are likely to receive an O&M-training in using the identification cane are included in the trial (N = 190). The primary outcomes of the effect evaluation are ADL self care and visual functioning with respect to distance activities and mobility. Secondary outcomes include quality of life, feelings of anxiety, symptoms of depression, fear of falling, and falls history. Data for the effect evaluation are collected by means of telephone interviews at baseline, and at 5 and 17 weeks after the start of the O&M-training. In addition to an effect evaluation, a process evaluation to study the feasibility of the O&M-training is carried out.</p> <p>Discussion</p> <p>The screening procedure for eligible participants started in November 2007 and will continue until October 2009. Preliminary findings regarding the evaluation are expected in the course of 2010. If the standardised O&M-training is more effective than the current O&M-training or, in case of equal effectiveness, is considered more feasible, the training will be embedded in the Dutch national instruction for mobility trainers.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00946062</p

Mid-Devensian climate and landscape in England : new data from Finningley, South Yorkshire

While there is extensive evidence for the Late Devensian, less is known about Early and Middle Devensian (approx. 110–30 ka) climates and environments in the UK. The Greenland ice-core record suggests the UK should have endured multiple changes, but the terrestrial palaeo-record lacks sufficient detail for confirmation from sites in the British Isles. Data from deposits at Finningley, South Yorkshire, can help redress this. A channel with organic silts, dated 40 314–39 552 cal a BP, contained plant macrofossil and insect remains showing tundra with dwarf-shrub heath and bare ground. Soil moisture conditions varied from free draining to riparian, with ponds and wetter vegetated areas. The climate was probably low arctic with snow cover during the winter. Mutual climatic range (MCR), based on Coleoptera, shows the mean monthly winter temperatures of −22 to −2°C and summer ones of 8–14°C. Periglacial structures within the basal gravel deposits and beyond the glacial limits indicate cold-climate conditions, including permafrost. A compilation of MCR reconstructions for other Middle Devensian English sites shows that marine isotope stage 3—between 59 and 28 ka—experienced substantial variation in climate consistent with the Greenland ice-core record. The exact correlation is hampered by temporal resolution, but the Finningley site stadial at approximately 40 ka may correlate with the one of the Greenland stadials 7–11

The value of plantation forests for plant, invertebrate and bird diversity and the potential for cross-taxon surrogacy

As the area of plantation forest expands worldwide and natural, unmanaged forests decline there is much interest in the potential for planted forests to provide habitat for biodiversity. In regions where little semi-natural woodland remains, the biodiversity supported by forest plantations, typically non-native conifers, may be particularly important. Few studies provide detailed comparisons between the species diversity of native woodlands which are being depleted and non-native plantation forests, which are now expanding, based on data collected from multiple taxa in the same study sites. Here we compare the species diversity and community composition of plants, invertebrates and birds in Sitka spruce- (Picea sitchensis-) dominated and Norway spruce- (Picea abies-) dominated plantations, which have expanded significantly in recent decades in the study area in Ireland, with that of oak- and ash-dominated semi-natural woodlands in the same area. The results show that species richness in spruce plantations can be as high as semi-natural woodlands, but that the two forest types support different assemblages of species. In areas where non-native conifer plantations are the principle forest type, their role in the provision of habitat for biodiversity conservation should not be overlooked. Appropriate management should target the introduction of semi-natural woodland characteristics, and on the extension of existing semi-natural woodlands to maintain and enhance forest species diversity. Our data show that although some relatively easily surveyed groups, such as vascular plants and birds, were congruent with many of the other taxa when looking across all study sites, the similarities in response were not strong enough to warrant use of these taxa as surrogates of the others. In order to capture a wide range of biotic variation, assessments of forest biodiversity should either encompass several taxonomic groups, or rely on the use of indicators of diversity that are not species based

Posterior cruciate ligament recruitment affects antero-posterior translation during flexion gap distraction in total knee replacement. An intraoperative study involving 50 patients.

Contains fulltext : 89724.pdf (publisher's version ) (Open Access)BACKGROUND AND PURPOSE: Because of the oblique orientation of the posterior cruciate ligament (PCL), flexion gap distraction could lead to anterior movement of the tibia, which would influence the tibiofemoral contact point. This would affect the kinematics of the TKR. We assessed the flexion gap parameters when the knee is distracted during implantation of a PCL-retaining TKR. Furthermore, the effects of PCL elevation (steep or flat) and collateral ligament releases on the flexion gap parameters were determined. METHODS: During a ligament-guided TKR procedure in 50 knees, the flexion gap was distracted with a double-spring tensor with 200N after the tibia had been cut. The flexion gap height, anterior tibial translation, and femoral rotation were measured intraoperatively using a CT-free navigation system. RESULTS: During flexion gap distraction, the greatest displacement was seen in anterior-posterior direction. Mean ratio between increase in gap height and tibial translation was 1 to 1.9, and was highest for knees with a steep PCL (1 to 2.3). Knees with a flat PCL and knees with a ligament release had a larger increase in PCL elevation when the gap was distracted. INTERPRETATION: When the PCL is tensioned, every extra mm that the flexion gap is distracted can be expected to move the tibia anteriorly by at least 1.7 mm (flat PCL), or more if there is a steep PCL. This changes the tibiofemoral contact point, which may have consequences for polyethylene wear.01 augustus 20107 p