Signatures of stirring and mixing near the Gulf Stream front

In October, 1986 the surface waters adjacent to the Gulf Stream front were surveyed with an undulating profiler to describe the finescale structure of the mixed layer. The profiler was a Seasoar equipped with a CTD and fluorometer. The survey first defined the structure of a cyclonic eddy which resembled frontal eddies of the South Atlantic Bight in sea surface temperature imagery. The Seasoar transects revealed, however, that the cyclonic eddy lacked a cold dome typically seen in frontal eddies. Farther downstream the Seasoar defined the structure of streamers of Gulf Stream and Shelf water wrapped about the southern edge of a warm-core ring. The streamers had lateral and along-axis dimensions on the order of ≈ 10 km and 100 km, respectively, and were bordered by narrow intrusive features. The temporal history of the streamers was described from SST imagery, and the surface flow derived from ship\u27s drift vectors. CTD casts taken while following an isopycnal float provided a means to examine the structure of the intrusive features. Interleaving was evident at the boundaries of the streamers and intrusive features where high conductivity Cox numbers were concentrated, suggesting elevated microstructure activity. The Turner angle distribution, indicating either saltfingering or diffusive convection, did not correlate well with the Cox number distribution. This is interpreted as evidence that lateral, rather than diapycnal, mixing was the process mediating the exchange of properties at the boundaries of contrasting water types. In contrast to physical properties, the distribution of fluorescence showed relatively less structure in the surface layer between the ring and Gulf Stream front. In the surface layers of the two streamers the pigment and bacterial biomass, and the diatom species composition, were typical of Slope water communities. We hypothesize that small-scale mixing processes concentrated at the boundaries of the streamers were the mechanism by which Slope water plankton were seeded into streamers of different hydrographic origins. Presumably, high netplankton growth rates allowed the Slope water species to dominate the communities in the streamers

Epidemiological findings and medical, legal, and public health challenges of an investigation of severe soft tissue infections and deaths among injecting drug users: Ireland, 2000.

In May 2000, public health authorities in Dublin, Ireland, identified a cluster of unexplained severe illness among injecting drug users (IDUs). Similar clusters were also reported in Scotland and England. Concurrent investigations were undertaken to identify the aetiology and source of the illnesses. In Dublin, 22 IDUs were identified with injection-site inflammation resulting in hospitalization or death; eight (36%) died. Common clinical findings among patients with severe systemic symptoms included leukaemoid reaction and cardiogenic shock. Seventeen (77%) patients reported injecting heroin intramuscularly in the 2 weeks before illness. Of 11 patients with adequate specimens available for testing, two (18%) were positive by 16S rDNA PCR for Clostridium novyi. Clinical and laboratory findings suggested that histotoxic Clostridia caused a subset of infections in these related clusters. Empiric treatment for infections among IDUs was optimized for anaerobic organisms, and outreach led to increased enrolment in methadone treatment in Dublin. Many unique legal, medical, and public health challenges were encountered during the investigation of this outbreak

Young people's views on the potential use of telemedicine consultations for sexual health: results of a national survey

<p>Abstract</p> <p>Background</p> <p>Young people are disproportionately affected by sexually transmissible infections in Australia but face barriers to accessing sexual health services, including concerns over confidentiality and, for some, geographic remoteness. A possible innovation to increase access to services is the use of telemedicine.</p> <p>Methods</p> <p>Young people's (aged 16-24) pre-use views on telephone and webcam consultations for sexual health were investigated through a widely-advertised national online survey in Australia. Descriptive statistics were used to describe the study sample and chi-square, Mann-Whitney U test, or t-tests were used to assess associations. Multinomial logistic regression was used to explore the association between the three-level outcome variable (first preference in person, telephone or webcam, and demographic and behavioural variables); odds ratios and 95%CI were calculated using in person as the reference category. Free text responses were analysed thematically.</p> <p>Results</p> <p>A total of 662 people completed the questionnaire. Overall, 85% of the sample indicated they would be willing to have an in-person consultation with a doctor, 63% a telephone consultation, and 29% a webcam consultation. Men, respondents with same-sex partners, and respondents reporting three or more partners in the previous year were more willing to have a webcam consultation. Imagining they lived 20 minutes from a doctor, 83% of respondents reported that their first preference would be an in-person consultation with a doctor; if imagining they lived two hours from a doctor, 51% preferred a telephone consultation. The main objections to webcam consultations in the free text responses were privacy and security concerns relating to the possibility of the webcam consultation being recorded, saved, and potentially searchable and retrievable online.</p> <p>Conclusions</p> <p>This study is the first we are aware of that seeks the views of young people on telemedicine and access to sexual health services. Although only 29% of respondents were willing to have a webcam consultation, such a service may benefit youth who may not otherwise access a sexual health service. The acceptability of webcam consultations may be increased if medical clinics provide clear and accessible privacy policies ensuring that consultations will not be recorded or saved.</p

Identifying priority healthcare trainings in frozen conflict situations: The case of Nagorno Karabagh

<p>Abstract</p> <p>Introduction</p> <p>Health care in post-war situations, where the system's human and fixed capital are depleted, is challenging. The addition of a frozen conflict situation, where international recognition of boundaries and authorities are lacking, introduces further complexities.</p> <p>Case description</p> <p>Nagorno Karabagh (NK) is an ethnically Armenian territory locked within post-Soviet Azerbaijan and one such frozen conflict situation. This article highlights the use of evidence-based practice and community engagement to determine priority areas for health care training in NK. Drawing on the precepts of APEXPH (Assessment Protocol for Excellence in Public Health) and MAPP (Mobilizing for Action through Planning and Partnerships), this first-of-its-kind assessment in NK relied on in-depth interviews and focus group discussions supplemented with expert assessments and field observations. Training options were evaluated against a series of ethical and pragmatic principles.</p> <p>Discussion and Evaluation</p> <p>A unique factor among the ethical and pragmatic considerations when prioritizing among alternatives was NK's ambiguous political status and consequent sponsor constraints. Training priorities differed across the region and by type of provider, but consensus prioritization emerged for first aid, clinical Integrated Management of Childhood Illnesses, and Adult Disease Management. These priorities were then incorporated into the training programs funded by the sponsor.</p> <p>Conclusions</p> <p>Programming responsive to both the evidence-base and stakeholder priorities is always desirable and provides a foundation for long-term planning and response. In frozen conflict, low resource settings, such an approach is critical to balancing the community's immediate humanitarian needs with sponsor concerns and constraints.</p

The Gulf Stream - Barrier or Blender?

The Gulf Stream ’60 hydrographic survey has been used to examine the distribution of water properties across the Gulf Stream as a function of potential density. This survey covered a half million square miles of Slope, Gulf Stream and Sargasso Sea Waters in the western North Atlantic. Quantities plotted as a function of density are acceleration potential, potential temperature, dissolved oxygen and potential vorticity. The transition from Sargasso Sea Water to Slope Water in the upper thermocline (σe \u3c 27.1) is sharp and coincides closely with the dynamical boundary of the Gulf Stream, defined by the gradient of acceleration potential. This indicates that water mass exchanges across the Gulf Stream-Slope Water front are limited at these levels. Below the 27.1 σe surface, the gradient of acceleration potential still reveals the position of the Stream, but there is no coincident water man boundary. This and the uniformity of potential vorticity across the Stream suggest that the deep property fields are being efficiently homogenized by mesoscale exchanges across the Gulf Stream. A cross-frontal eddy diffusivity of K11 =2.5×106 cm2 s−1 estimated from oxygen flux calculations agrees well with previously published values for frontal regimes

A statistical analysis of Gulf Stream variability from 18+ years of altimetry data

Altimetry data that bracket the core of the Gulf Stream (GS) between 32–39°N and 68–72°W are analyzed from a combined data set spanning the duration of the Topex, Jason-1, and Jason-2 missions. Absolute sea surface height, SSH, referenced to a geoid model and sea surface height anomaly, SSHA, referenced to a global mean sea surface model are calculated using pass 50 data from Topex cycle-002 (04-October-1992) through Jason-2 cycle-098 (02-Mar-2011). Five different indices of GS variability: (i) ΔSSH—the change in absolute height across the GS; (ii) ΔSSHA—the change in sea surface height anomaly across the GS; (iii) a barotropic velocity index; (iv) a baroclinic transport index; and (v) the position of the GS, are estimated from the 18+ year time series via seasonal time series, power spectral density functions, auto-covariance functions, and a principal component analysis (PCA). The average annual distribution of all the variables except velocity index increases from a spring/summer minimum to a fall maximum, then decreases during the winter to minimum values in spring and early summer. The average signal in barotropic velocity index reaches a maximum in summer, whereas the maximum baroclinic transport occurs in the fall. The seasonal signal in GS position is better approximated by a seasonal sinusoid than the dynamical variables, with minimum (southerly) positions in spring and maximum (northerly) positions in the fall. Variations in height difference across the current are in phase with changes in the width of the current, leading to smaller seasonal variations in the velocity which are out of phase with the other variables. None of the seasonal time series except GS position resemble a pure sinusoid; they more closely resemble the signal of a nonlinear oscillator. The three dominant periods for ΔSSH are 15–21 months, 7 months, and 4 years, with an integral time scale of 32 days. The dominant periods for ΔSSHA are 9 months, 21 months, and 5–6 months, with an integral time scale of 38 days. The spectral and PCA analyses of both ΔSSH and ΔSSHA are “pink”, indicating an energetic broad-band spectra. The dominant PCA modes explain less than 30% of the variability, indicative of highly nonlinear processes. The dominant periods for the barotropic velocity index are 9 months, 21 months, and 5 months, with an integral time scale of 14 days. The dominant periods for the baroclinic transport index are 11 months, 2–3 months, and monthly, with an integral time scale of 24 days. The dominant PCA modes of the velocity and transport indices explain 52% and 48% of the variability of their respective time series. The dominant periods for GS position are 9, 11, 13 months, and 1.5–6 years, with an integral time scale of 35 days. The first GS position PCA mode explains 50% of position variability. All of the time series of GS variability and the correlation between the North Atlantic Oscillation and GS position exhibit non-stationary behavior