High resolution forecast models of water vapour over mountains: comparison of results from the UM and MERIS

Propagation delay due to variable tropospheric water vapor (WV) is one of the most intractable problems for radar interferometry, particularly over mountains. The WV field can be simulated by an atmospheric model, and the difference between the two fields is used to correct the radar interferogram. Here, we report our use of the U.K. Met Office Unified Model in a nested mode to produce high-resolution forecast fields for the 3-km-high Mount Etna volcano. The simulated precipitablewater field is validated against that retrieved from the Medium Resolution Imaging Spectrometer (MERIS) radiometer on the Envisat satellite, which has a resolution of 300 m. Two case studies, one from winter (November 24, 2004) and one from summer (June 25, 2005), show that the mismatch between the model and the MERIS fields (rms = 1.1 and 1.6 mm, respectively) is small. One of the main potential sources of error in the models is the timing of the WV field simulation. We show that long-wavelength upper tropospheric troughs of low WV could be identified in both the model output and Meteosat WV imagery for the November 24, 2004 case and used to choose the best time of model output. © 2007 IEEE

The P Cygni supergiant [OMN2000] LS1 – implications for the star formation history of W51

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200911980Aims. We investigate the nature of the massive star [OMN2000] LS1 and use these results to constrain the history of star formation within the host complex W51. Methods. We utilised a combination of near-IR spectroscopy and non-LTE model atmosphere analysis to derive the physical properties of [OMN2000] LS1 , and a combination of theoretical evolutionary calculations and Monte Carlo simulations to apply limits on the star formation history of W51. Results. We find the spectrum of [OMN2000] LS1 to be consistent with that of a P Cygni supergiant. With a temperature in the range of 13.2–13.7 kK and log( ) , it is significantly cooler, less luminous, and less massive than proposed by previous authors. The presence of such a star within W51 shows that star formation has been underway for at least 3 Myr, while the formation of massive O stars is still on going. The lack of a population of evolved red supergiants within the complex shows that the rate of formation of young massive clusters at ages 9 Myr was lower than currently observed. We find no evidence of internally triggered, sequential star formation within W51, and favour the suggestion that star formation has proceeded at multiple indepedent sites within the GMC. Along with other examples, such as the G305 and Carina star-forming regions, we suggest that W51 is a Galactic analogue of the ubiquitous star cluster complexes seen in external galaxies such as M51 and NGC2403.Peer reviewe

The oxygen affinity of haemoglobin St. Luke's

Podeu consultar la versió en castellà a:http://hdl.handle.net/11703/8763

Counselling in primary care : a systematic review of the evidence

Primary objective: To undertake a systematic review which aimed to locate, appraise and synthesise evidence to obtain a reliable overview of the clinical effectiveness, cost-effectiveness and user perspectives regarding counselling in primary care. Main results: Evidence from 26 studies was presented as a narrative synthesis and demonstrated that counselling is effective in the short term, is as effective as CBT with typical heterogeneous primary care populations and more effective than routine primary care for the treatment of non-specific generic psychological problems, anxiety and depression. Counselling may reduce levels of referrals to psychiatric services, but does not appear to reduce medication, the number of GP consultations or overall costs. Patients are highly satisfied with the counselling they have received in primary care and prefer counselling to medication for depression. Conclusions and implications for future research: This review demonstrates the value of counselling as a valid choice for primary care patients and as a broadly effective therapeutic intervention for a wide range of generic psychological conditions presenting in the primary care setting. More rigorous clinical and cost-effectiveness trials are needed together with surveys of more typical users of primary care services

Using GIS to integrate old and new archaeological data from Stone Age deposits in Karonga, Malawi

The Karonga District of northern Malawi has an extensive Stone Age archaeological record, primarily represented by stone artefacts that occur in both superficial and buried contexts. Work conducted in the 1960s provided initial documentation of this record. Some of this was presented in summary form in a small number of publications. However, most data were restricted to unpublished field notes, maps, and other static or largely inaccessible formats. GIS has been an essential tool for bringing together these diverse datasets in a digital format to facilitate integration of new research and promote reinvestigation of old sites. Examples from both the regional and site scale demonstrate how old data have been combined with recent survey and excavation data to document, analyse, interpret, and archive current knowledge about the rich Stone Age record of northern Malawi. A significant result from this approach has been the suggested reinterpretation of the Mwanganda’s Village Site

Development of Luminescence Tests to Identify Irradiated Foods. Project N1701

<p>This is the final report of project N170l, commissioned by MAFF from October 1990 until March 1992. The principle aims of the project, at a time when statutory changes involving strict labelling rules were anticipated, were to consolidate the thermoluminescence technique already developed at SURRC and to investigate it's extension to fruits and vegetables.</p> <p>The TL procedures for mineral separation were further developed by the incorporation of pre-concentration steps. These steps were introduced in order to improve the the sensitivity of the TL signal, particularly, where the separation technique resulted in low mineral yield for commercially clean samples. This has resulted in an order of magnitude increase in the absolute, TL, signal levels and provides a means of obtaining larger quantities of minerals for any further quantification, thus reducing the ambiguity of interpretation of data.</p> <p>An EC interlaboratory trial was instigated, using the full mineral separation method with reirradiation on a set of calibrated reference materials and paired (irradiated and unirradiated) samples of 12 commercial grade herbs and spices. Despite the diversity of experience and equipment employed, results from all laboratories showed that it was possible to determine which samples were irradiated. This demonstrated the strength of the separation method that its implementation could be successfully achieved in other laboratories. The procedure was then formally recognised and published, by MAFF, for detection of irradiated food for enforcement of UK legislation.</p> <p>As the mineral debris responsible for TL in herbs and spices occurs ubiquitously on all foodstuffs, which have been exposed to wind and soil, investigating the application of TL to fruits and vegetables was a natural extension of the previous work. An extensive survey was conducted of TL signals from fruits and vegetables, including exotic varieties. Minerals were separated from duplicated pairs of irradiated and unirradiated samples of 22 fruits and 20 vegetables. TL results demonstrated unambiguous discrimination between irradiated and unirradiated vegetables provided that concordance diagrams were used. For soft fruits in particular water based separation produced more variable results. However, subsequent analyses using a full density separation with HCI wash were more successful. It was recognised that whereas herbs and spices are largely protected from exposure to light during production and distribution, this is unlikely to be the case for fruits and vegtables. Since light exposure is known to reduce TL signal intensity, a set of illumination experiments was conducted to investigate the implications of optical bleaching for identification. Light boxes were constructed and characterised to simulated optical bleaching under controlled conditions. Two series of experiments were conducted with irradiated and control mangos. In the first experiment the effects of exposure to two different light sources at a level of 1 J cm-2 were investigated using 40 mangos. In the second experiment the influence of duration of exposure from 1 - 128 J cm-2 was examined for artificial daylight illumination of a further 96 mangos. The results of these studies show that although the TL signal is reduced as a result of exposure to daylight, there exists a residual unbleachable component comprising upto 40-50% of the original signal. In most cases the resulting TL will be distinguishable from background levels.</p> <p>As a result of this work it is now possible to extend TL detection protocols to a wide range of fruits and vegetables. Providing that recontamination with unirradiated minerals has not occurred after irradiation, the majority of treated fruits and vegetables are expected to be detectable. Positive signals will imply an irradiation treatment. There remains some possibility of false negative results from a small proportion of irradiated products.</p&gt

Effect of Cement Base Thicknesses on MOD Amalgam Restorations

The effect of five cement bases on the fracture strength of three amalgams was determined at 24 h after condensation. It was found that the type of base used was the most important factor in affecting the fracture strength of the amalgam, followed by the thickness of the base, and finally the type of amalgam that was used.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67857/2/10.1177_00220345830620020301.pd

Search for Oscillation of the Electron-Capture Decay Probability of 142^{142}Pm

We have searched for time modulation of the electron capture decay probability of $^{142}$Pm in an attempt to confirm a recent claim from a group at the Gesellschaft f\"{u}r Schwerionenforschung (GSI). We produced $^{142}$Pm via the $^{124}$Sn($^{23}$Na, 5n)$^{142}$Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the $^{142}$Nd K$_{\alpha}$ x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov {\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079 [nucl-ex]). A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in $^{142}$Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.Comment: 12 pages (double-spaced), 6 figure

Hardware and software status of QCDOC

QCDOC is a massively parallel supercomputer whose processing nodes are based on an application-specific integrated circuit (ASIC). This ASIC was custom-designed so that crucial lattice QCD kernels achieve an overall sustained performance of 50% on machines with several 10,000 nodes. This strong scalability, together with low power consumption and a price/performance ratio of $1 per sustained MFlops, enable QCDOC to attack the most demanding lattice QCD problems. The first ASICs became available in June of 2003, and the testing performed so far has shown all systems functioning according to specification. We review the hardware and software status of QCDOC and present performance figures obtained in real hardware as well as in simulation.Comment: Lattice2003(machine), 6 pages, 5 figure