The impacts of withdrawal and replacement of general practitioner services on aeromedical service trends: A 13-year interrupted time-series study in Tennant Creek, Northern Territory

Background: The Royal Flying Doctor Service, RFDS, provides aeromedical care to patients during fixed-wing transport over vast distances to healthcare unavailable in rural or remote communities. This study examined the relationship between changes in local accessibility to primary healthcare services and rates of aeromedical service use over time. Methods: This was a, 13-year interrupted time-series study (1999–2012) in Tennant Creek, Northern Territory. Quarterly aeromedical service use for primary care sensitive conditions were calculated and exposure to general practice, GP, services was characterised over time with events modelled as intervention variables, a, GP service withdrawal, Nov- 2004, and (b,) GP service replacement, Dec2006, . Intervention effects were estimated using PROC ARIMA in SAS after examination of the time-series structure. Results GP withdrawal resulted in an immediate and sustained doubling in quarterly aeromedical service use (+11.8 services per quarter) services per quarter, and GP service replacement had no significant effect. Discussion: Large and immediate increases in aeromedical service use result from the loss of local GP services yet, in this case, replacement with a new GP service, 2-years hence, did not ameliorate that effect after six years. Conclusions: These findings demonstrate the immediate impact of GP-service loss on the rates of aeromedical transfer of patients from this remote community and lend caution to expectations about the timeline over which newly implemented primary health care services in such contexts can mitigate the impact of such a loss.Matthew T. Haren, John Setchell, David L. John and Mark Danie

Vierzig Jahre Sechstagekrieg : Strukturelle Prägekraft für den Nahen Osten

Circulation patterns and sediment dynamics were studied over the Gulf of Valencia (GoV) continental slope during spring and winter 2011–2012. Two moorings were deployed at two locations; at 450 m depth from February to May 2011, and at 572 m depth from October 2011 to February 2012. At both mooring sites, observations were made of currents, temperature and near-bottom turbidity within the lowermost 80 m above the seafloor. The temperature measurements allowed distinction of the different water masses and their temporal evolution. The fluctuations of the boundary between the Western Mediterranean Deep Water (WMDW) and the Levantine Intermediate Water (LIW) masses were monitored, and several intrusions of Western Mediterranean Intermediate Water (WIW) were observed, generally coinciding with changes in current direction. At both mooring sites, the currents generally maintained low velocities <10 cm s-1, with several pulses of magnitude increases >20 cm s-1, and few reaching up to 35 cm s-1, associated with mesoscale eddies and topographic waves. The current direction was mainly towards the SSE on the first deployment and to the ESE on the second deployment. This second location was affected by a strong bottom offshore veering presumably generated by local topographic effects. Increases in suspended sediment concentrations (SSC) were observed repeatedly throughout the records, reaching values >3 mg l-1. However, these SSC variations were uncorrelated with changes in velocity magnitude and direction and/or with temperature oscillations. Results presented in this paper highlight the complex relation between the hydrodynamics and sediment transport over the GoV continental slope, and suggest that other potential sediment resuspension mechanism not linked with current fluctuations, might play a key role in the present-day sedimentary dynamics. Resuspension due to bottom trawling appears to be the most plausible mechanis

Observations on the vertical structure of tidal and inertial currents in the central North Sea

Tidal and inertial current ellipses, measured at several locations and depths in the central North Sea during a number of monthly periods in 1980, 1981 and 1982, are decomposed into counterrotating, circular components to which Ekman dynamics are applied to determine Ekman layer depths and vertical phase differences, from which are inferred overall values of the eddy viscosity and drag coefficient. Stratification effects produce an additional vertical phase shift of the anticyclonic rotary component, indicative of an inverse proportionality of the eddy viscosity to the vertical density gradient. From the time variations of the Ekman layer depths of the semidiurnal tidal components, as well as from the vertical structure of the inertial current component, we infer variations in the relative vorticity of the low-frequency flow

Fast thermistor string observations at the slope of Great Meteor Seamount

International audienceA very fast thermistor string has been built to accommodate the scientific need to accurately monitor fast and vigorous internal wave and overturning processes above sloping bottoms in the ocean. The thermistors and their custom designed electronics can register temperature at an estimated precision of about 1mK with a response time faster than 0.25 s down to depths of 6000 m. The present string holds 128 synoptically measuring sensors at 0.5 m intervals, which are all read-out within 0.5 s. When sampling at 1Hz, the batteries and the memory capacity of the recorder allow for deployments of up to 2 weeks. Detailed examples of the first field observations are presented, which show overturning and very high-frequency (Doppler-shifted) internal waves besides occasionally large turbulent bores moving up the sloping side of Great Meteor Seamount, Canary Basin, North-Atlantic Ocean

High sampling rate thermistor string observations at the slope of Great Meteor Seamount

International audienceA high sampling rate (1 Hz) thermistor string has been built to accommodate the scientific need to accurately monitor high-frequency and vigorous internal wave and overturning processes in the ocean. The thermistors and their custom designed electronics can register temperature at an estimated precision of about 0.001° C with a response time faster than 0.25 s down to depths of 6000 m. With a quick in situ calibration using SBE 911 CTD an absolute accuracy of 0.005° C is obtained. The present string holds 128 sensors at 0.5 m intervals, which are all read-out within 0.5 s. When sampling at 1 Hz, the batteries and the memory capacity of the recorder allow for deployments of up to 2 weeks. In this paper, the instrument is described in some detail. Its performance is illustrated with examples from the first moored observations, which show Kelvin-Helmholtz overturning and very high-frequency (Doppler-shifted) internal waves besides occasionally large turbulent bores moving up the sloping side of Great Meteor Seamount, Canary Basin, North-Atlantic Ocean

Do plant species influence soil gas fluxes in tropical forests?

Abstract ID: 53. Publicado também on-line

Patchiness in internal tidal beams

Results are presented from measurements on internal tides and near-inertial motions, obtained using deep-towed acoustic Doppler current profilers along a single transect over the continental slope in the Bay of Biscay and, in another experiment, over a flank of Great Meteor Seamount in the Canary Basin. Each measurement lasted two days and involved repeated passage of the same track, making it possible to extract by harmonic analysis the semidiurnal (and, over Great Meteor Seamount, also the combined diurnal/near-inertial) signal. In the Bay of Biscay, the transect covered by the towing was sufficiently long to follow the internal semidiurnal tidal beam for large-scale stratification well beyond its detachment from the continental slope. Here, large-scale stratification is computed from CTD-observations over vertical scales O(100 m). Remarkably, the beam is much more distinct in its phase field, which is coherent throughout, than in its amplitude, which shows a lot of patchiness and small-scale near-horizontal layering. The hypothesis is put forward that this may be associated with the interaction between internal waves and variations in space and time of stratification. In part, it may be attributable to aliased, weaker, near-inertial beams that are more horizontal for large-scale stratification. The diurnal/inertial and, to a lesser extent, semidiurnal signals over Great Meteor Seamount show the same phenomenon, but here co-phase and coamplitude bands are more distinctly nearly horizontal, indicative of near-horizontal energy propagation at all frequencies investigated

Testing the use of sealable bags as an alternative and less expensive method for tracing isotopes in plant matter

The main purpose of the research was to find a less expensive method for sampling isotopes from plants. By collecting plant xylem in a plastic, sealable bag, filling the bag with dry air, letting it sit for 24 hours and then running it through the laser spectrometer, the isotopes of the plants will be traced; specifically, deuterium and oxygen-18. The bag method of this experiment comes from that of Hendry (2015) when he used it on soils. Once the raw data was collected it was transposed from vapor to liquid data. The values found match with previous isotopic collections that were done using IR mass spectrometry. This shows that this inexpensive method was comparable to previous methods and can allow for the study of isotopes to be more accessible to the scientific community

Detailed observations of the phytoplankton spring bloom in the stratifying central North Sea

Analysis of detailed time series of bio-optical and temperature data from the North Sea supports the view that a minimum level of turbulence is a prerequisite for the onset and maintenance of the phytoplankton spring bloom in shelf seas, which distinguishes these seas from the open ocean. The start of the spring bloom, primarily diatoms, is controlled by the light regime, while its progress is predominantly dependent upon episodic turbulence input following short periods of stratification, which allow the resuspension of a fast sinking (50-200 m day-1) phytoplankton community from the bottom mixing layer. A relationship between turbulence and the vertical distribution of phytoplankton is proposed which is found at synoptic time scales and on time scales of a day and less. Throughout the spring bloom, algal biomass is either equally distributed through the water column or concentrated in the bottom mixing layer. Growth can only be sustained in the near-surface layer during periods of substantial turbulence input. The establishment of semi-permanent seasonal stratification causes an almost complete reduction in near-surface biomass and a concomitant increase in biomass in the bottom mixing layer which subsequently acts as a source for occasional increased near-surface biomass until early summer