6,018 research outputs found
Optimized temporal binning of comparison star measurements for differential photometry
Ground-based, high precision observations of the light curves of objects such as transiting exoplanets rely on the application of differential photometry. The flux of the target object is measured relative to a comparison star in the same field, allowing correction for systematic trends in the light curve, mainly due to atmospheric effects including the variation of extinction with airmass. However, the precision of the light curve is then limited by the random noise for the measurements of both the target object and the comparison star. For time-resolved photometry using short exposure times of up to a few tens of seconds, the time-scale of the systematic variations due to atmospheric (or other) effects can be much longer than the cadence of the observations. In this case, the overall signal-to-noise ratio of the observation may be improved significantly by applying some temporal binning to the measurements of the comparison star, before comparison with the target object, without reducing the cadence of the overall light curve. In this paper, we will describe a data reduction pipeline for implementing this method which optimizes the number of frames to be binned for the comparison star, and we present example results for time-resolved photometric data. An example of applying the technique on an exoplanet transit light curve of WASP-166b is presented using four comparison stars of different magnitudes
Intensive care in labour: A preliminary appraisal
This is a preliminary investigation into the value, function and practicability of an intensive care labour unit for highrisk cases. All the equipment necessary can be mounted on two standard theatre trolleys which can be moved to the patient's bedside, but there is no place at present for this equipment outside a teaching unit. The investigation reports on continuous foetal heart monitoring of 36 patients and simultaneous foetal scalp pH estimations on 16 of them. A high proportion of babies with low Apgar scores showed one of two (or both) characteristic foetal heart patterns during labour: (a) the well-known type 2 dip, (b) a steppe pattern not previously described as such. The latter is of importance because it is impossible to detect using only clinical methods. There was poor correlation between foetal pH values and Apgar rating, and between foetal pH values and monitor patterns. Moreover, the pH values of foetal scalp blood and foetal umbilical arterial and venous blood samples bore varying relations to one another. However, for practical purposes, a foetal scalp blood of pH less than 7¡20 when associated with a maternofoetal pH difference of 0¡250 or more should be regarded with anxiety. The place and value of intensive care are discussed
NGO perspectives on the social and ethical dimensions of plant genome-editing
Plant genome editing has the potential to become another chapter in the intractable debate that has dogged agricultural biotechnology. In 2016, 107 Nobel Laureates accused Greenpeace of emotional and dogmatic campaigning against agricultural biotechnology and called for governments to defy such campaigning. The Laureates invoke the authority of science to argue that Greenpeace is putting lives at risk by opposing agricultural biotechnology and Golden Rice and is notable in framing Greenpeace as unethical and its views as marginal. This paper examines environmental, food and farming NGOsâ social and ethical concerns about genome editing, situating these concerns in comparison to alternative ethical assessments provided by the Nuffield Council on Bioethics, a key actor in this policy debate. In doing so, we show that participant NGOs and the Nuffield Council on Bioethics share considerable concerns about the social and ethical implications of genome editing. These concerns include choices over problem/solution framing and broader terminology, implications of regulatory and research choices on consumer choice and relations of power. However, GM-engaged NGOs and the Nuffield Council on Bioethics diverge on one important area: the NGOs seek to challenge the existing order and broaden the scope of debate to include deeply political questions regarding agricultural and technological choices. This distinction between the ethical positions means that NGOs provide valuable ethical insight and a useful lens to open up debate and discussion on the role of emerging technologies, such as genome editing, and the future of agriculture and food sovereignty
Intensive care in labour: a preliminary appraisal
This is a preliminary investigation into the value, function and practicability of an intensive care labour unit for highrisk cases. All the equipment necessary can be mounted on two standard theatre trolleys which can be moved to the patient's bedside, but there is no place at present for this equipment outside a teaching unit. The investigation reports on continuous foetal heart monitoring of 36 patients and simultaneous foetal scalp pH estimations on 16 of them. A high proportion of babies with low Apgar scores showed one of two (or both) characteristic foetal heart patterns during labour: (a) the well-known type 2 dip, (b) a steppe pattern not previously described as such. The latter is of importance because it is impossible to detect using only clinical methods.There was poor correlation between foetal pH values and Apgar rating, and between foetal pH values and monitor patterns. Moreover, the pH values of foetal scalp blood and foetal umbilical arterial and venous blood samples bore varying relations to one another. However, for practical purposes, a foetal scalp blood of pH less than 7¡20 when associated with a maternofoetal pH difference of 0¡250 or more should be regarded with anxiety. The place and value of intensive care are discussed
Tracking sand-fairways through a deformed turbidite system : the Numidian (Miocene) of Central Sicily, Italy
The research presented here is funded by BG Group in partnership with CNPq-Brazil (National Council for Scientific and Technological Development). Rosanna Maniscalco acknowledges a FIR 2014 grant awarded from the University of Catania. We thank Christian Haug Eide, David Hodgson and Enrico Tavarnelli for constructive and thorough reviews on an earlier draft that have greatly improved this contribution.Peer reviewedPublisher PD
On Parametrically Excited Flexural Motion of an Extensible and Shearable Rod with a Heavy Attachment
A simple Cosserat model is used to explore the coupled planar flemural and arial vibrations of a slender rod clamped at one end with a heauy attached mass free to move at the other. By assuming that the inertia of the rod is small compared to that of the attached mass it is shown how the equations of motionreduce to a dynamical system. The effects of grauity on the rod can be incorporated within this frame-work and the linearised stability of the system discussed in terms of solutions to the Mathieu-Hill equation
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