3,211 research outputs found
High-resolution and non-invasive 3D-visualisation of soft tissues in vertebrates: the use of OPFOS
The algorithm for FIR corrections of the VELO analogue links and its performance
The data from the VELO front-end is sent to the ADCs on the read-out board over a serial analogue link. Due imperfections in the link, inter-symbol cross talk occurs between adjacent time-bins in the transfer. This is corrected by an FIR filter implemented in the pre-processing FPGA locacted on the read-out board. This note reports on a method to determine the coefficients for the filter using date taken in-situ. Simulations are presented that show the performance of the methods as it is implemented in the LHCb read-out board. The effectiveness of the algorithm is demonstrated by the improvements in tracking performance on beam test data it brings
User-driven design of decision support systems for polycentric environmental resources management
Open and decentralized technologies such as the Internet provide increasing opportunities to create knowledge and deliver computer-based decision support for multiple types of users across scales. However, environmental decision support systems/tools (henceforth EDSS) are often strongly science-driven and assuming single types of decision makers, and hence poorly suited for more decentralized and polycentric decision making contexts. In such contexts, EDSS need to be tailored to meet diverse user requirements to ensure that it provides useful (relevant), usable (intuitive), and exchangeable (institutionally unobstructed) information for decision support for different types of actors. To address these issues, we present a participatory framework for designing EDSS that emphasizes a more complete understanding of the decision making structures and iterative design of the user interface. We illustrate the application of the framework through a case study within the context of water-stressed upstream/downstream communities in Lima, Peru
The use of semi-structured interviews for the characterisation of farmer irrigation practices
For the development of sustainable and realistic water security, generating
information on the behaviours, characteristics, and drivers of users, as well
as on the resource itself, is essential. In this paper we present a
methodology for collecting qualitative and quantitative data on water use
practices through semi-structured interviews. This approach facilitates the
collection of detailed information on actors' decisions in a convenient and
cost-effective manner. Semi-structured interviews are organised around a
topic guide, which helps lead the conversation in a standardised way while
allowing sufficient opportunity for relevant issues to emerge. In addition,
they can be used to obtain certain types of quantitative data. While not as
accurate as direct measurements, they can provide useful information on local
practices and users' insights. We present an application of the methodology
on farmer water use in two districts in the state of Uttar Pradesh in
northern India. By means of 100 farmer interviews, information was collected on
various aspects of irrigation practices, including irrigation water volumes,
irrigation cost, water source, and their spatial variability. Statistical
analyses of the information, along with data visualisation, are also
presented, indicating a significant variation in irrigation practices both within and
between districts. Our application shows that semi-structured interviews are
an effective and efficient method of collecting both qualitative and
quantitative information for the assessment of drivers, behaviours, and their
outcomes in a data-scarce region. The collection of this type of data could
significantly improve insights on water resources, leading to more realistic
management options and increased water security in the future
The OPFOS microscopy family: High-resolution optical-sectioning of biomedical specimens
We report on the recently emerging (Laser) Light Sheet based Fluorescence
Microscopy field (LSFM). The techniques used in this field allow to study and
visualize biomedical objects non-destructively in high-resolution through
virtual optical sectioning with sheets of laser light. Fluorescence originating
in the cross section of the sheet and sample is recorded orthogonally with a
camera. In this paper, the first implementation of LSFM to image biomedical
tissue in three dimensions - Orthogonal-Plane Fluorescence Optical Sectioning
microscopy (OPFOS) - is discussed. Since then many similar and derived methods
have surfaced (SPIM, Ultramicroscopy, HR-OPFOS, mSPIM, DSLM, TSLIM...) which we
all briefly discuss. All these optical sectioning methods create images showing
histological detail. We illustrate the applicability of LSFM on several
specimen types with application in biomedical and life sciences.Comment: 19 pages, 10 figures, to be published in Anatomical Research
International (Hindawi
Morphology and function of Bast’s valve: additional insight in its functioning using 3D-reconstruction
The utriculo-endolymphatic valve was discovered by Bast in 1928. The function of Bast’s valve is still unclear. By means of orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy 3D-reconstructions of the valve and its surrounding region are depicted. The shape of the duct at the utricular side is that of a flattened funnel. In the direction of the endolymphatic duct and sac this funnel runs into a very narrow duct. The valve itself has a rigid ‘arch-like’ configuration. The opposing thin, one cell-layer thick, utricular membrane is highly compliant. We propose that opening and closure of the valve occurs through movement of the flexible base/utricular membrane away from and toward the relatively rigid valve lip
Hydrological regime of remote catchments with extreme gradients under accelerated change: the Baker basin in Patagonia
The Baker basin (27 000 km2) is located in one of the most pristine and remote areas of the planet. Its hydrological regime is poised to undergo dramatic changes in the near future due to hydropower development and climate change. The basin contains the second-largest lake in South America, and part of a major icefield. This study documents the natural baseline of the Baker River basin, discusses the main hydrological modes and analyses the potential for sustainable management. Annual precipitation varies several-fold from the eastern Patagonian steppes to the North Patagonian Icefield. The westernmost sub-basins are strongly governed by glacier melt with a peak discharge in the austral summer (January–March). The easternmost sub-basins have a much more seasonal response governed by quicker snowmelt in spring (November–December), while they exhibit low flows typical for semi-arid regions during summer and autumn. Topography, vegetation and wetlands may also influence streamflow. The strong spatio-temporal gradients and variability highlight the need for further monitoring, particularly in the headwaters, especially given the severe changes these basins are expected to undergo. The great diversity of hydrological controls and climate change pose significant challenges for hydrological prediction and management
Characterisation of Medipix3 Silicon Detectors in a Charged-Particle Beam
While designed primarily for X-ray imaging applications, the Medipix3 ASIC
can also be used for charged-particle tracking. In this work, results from a
beam test at the CERN SPS with irradiated and non-irradiated sensors are
presented and shown to be in agreement with simulation, demonstrating the
suitability of the Medipix3 ASIC as a tool for characterising pixel sensors.Comment: 16 pages, 13 figure
Prognostic value of bcl-2 expression in invasive breast cancer.
Expression of the bcl-2 proto-oncogene was studied immunohistochemically in 251 invasive ductal breast carcinomas (median follow-up time 91 months, range 24-186 months) and the results were correlated with clinicopathological data and prognostic variables. Sixty-three (25%) tumours were scored bcl-2 negative and 188 (75%) tumours were bcl-2 positive. No relationship could be observed between bcl-2 status and tumour grade, pTNM staging or menopausal status. A strong positive relationship was demonstrated between bcl-2 immunoreactivity and oestrogen receptor status (P < 0.001) and progesterone receptor status (P < 0.001). No prognostic value was demonstrated for bcl-2 expression on disease-free survival and overall survival in axillary node-negative breast cancer patients. However, in axillary node-positive breast cancer patients multivariate analysis demonstrated absence of bcl-2 expression to be independently related to shortened disease-free survival (P = 0.003) and shortened overall survival (P < 0.001). Our results suggest a potential important role for bcl-2 expression as a modulator of response to adjuvant therapy in breast cancer
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