6,935 research outputs found
Does online sexually transmitted infection screening compromise care? A service evaluation comparing the management of chlamydial infection diagnosed online and in clinic
Patient demand on sexual health services (SHS) in the UK is so high that many services have introduced online screening to accommodate more patients. There are concerns that these services may not be accessible to all. This service evaluation was undertaken to determine whether online screening is accessible by those patients most at need by comparing the demographics and number of asymptomatic chlamydial infections detected online and in clinic. No difference was found in the age nor level of deprivation, demonstrating that online services are an accessible way to screen for STIs without overburdening established services
The Iliadās big swoon: a case of innovation within the epic tradition
In book 5 of the Iliad Sarpedon suffers so greatly from a wound that his āāĻĻ
ĻĪ® leaves himā. Rather than dying, however, Sarpedon lives to fight another day. This paper investigates the phrase Ļį½øĪ½ Ī“į½² Ī»ĪÆĻĪµ ĻĻ
ĻĪ® in extant archaic Greek poetry to gain a sense of its traditional referentiality and better assess the meaning of Sarpedonās swoon. Finding that all other instances of the ĻĻ
ĻĪ® leaving the body signify death, it suggests that the Iliad exploits a traditional unit of utterance to flag up the importance of Sarpedon to this version of the Troy story
Fractionation of sulfur isotopes during heterogeneous oxidation of SO<sub>2</sub> on sea salt aerosol: a new tool to investigate non-sea salt sulfate production in the marine boundary layer
The oxidation of SO<sub>2</sub> to sulfate on sea salt aerosols in the marine environment is highly important because of its effect on the size distribution of sulfate and the potential for new particle nucleation from H<sub>2</sub>SO<sub>4</sub> (g). However, models of the sulfur cycle are not currently able to account for the complex relationship between particle size, alkalinity, oxidation pathway and rate ā which is critical as SO<sub>2</sub> oxidation by O<sub>3</sub> and Cl catalysis are limited by aerosol alkalinity, whereas oxidation by hypohalous acids and transition metal ions can continue at low pH once alkalinity is titrated. We have measured <sup>34</sup>S/<sup>32</sup>S fractionation factors for SO<sub>2</sub> oxidation in sea salt, pure water and NaOCl aerosol, as well as the pH dependency of fractionation. <br><br> Oxidation of SO<sub>2</sub> by NaOCl aerosol was extremely efficient, with a reactive uptake coefficient of ā0.5, and produced sulfate that was enriched in <sup>32</sup>S with α<sub>OCl</sub> = 0.9882Ā±0.0036 at 19 Ā°C. Oxidation on sea salt aerosol was much less efficient than on NaOCl aerosol, suggesting alkalinity was already exhausted on the short timescale of the experiments. Measurements at pH = 2.1 and 7.2 were used to calculate fractionation factors for each step from SO<sub>2</sub>(g) ā multiple steps ā SO<sub>OCl</sub><sup>2−</sup>. Oxidation on sea salt aerosol resulted in a lower fractionation factor than expected for oxidation of SO<sub>3</sub><sup>2−</sup> by O<sub>3</sub> (α<sub>seasalt</sub> = 1.0124Ā±0.0017 at 19 Ā°C). Comparison of the lower fractionation during oxidation on sea salt aerosol to the fractionation factor for high pH oxidation shows HOCl contributed 29% of S(IV) oxidation on sea salt in the short experimental timescale, highlighting the potential importance of hypohalous acids in the marine environment. <br><br> The sulfur isotope fractionation factors measured in this study allow differentiation between the alkalinity-limited pathways ā oxidation by O<sub>3</sub> and by Cl catalysis (α<sub>34</sub> = 1.0163±0.0018 at 19 Ā°C in pure water or 1.0199±0.0024 at pH = 7.2) ā which favour the heavy isotope, and the alkalinity non-limited pathways ā oxidation by transition metal catalysis (α<sub>34</sub> = 0.9905Ā±0.0031 at 19 Ā°C, Harris et al., 2012a) and by hypohalites (α<sub>34</sub> = 0.9882Ā±0.0036 at 19 Ā°C) ā which favour the light isotope. In combination with field measurements of the oxygen and sulfur isotopic composition of SO<sub>2</sub> and sulfate, the fractionation factors presented in this paper may be capable of constraining the relative importance of different oxidation pathways in the marine boundary layer
Changes in Prandial Glucagon Levels After a 2-Year Treatment With Vildagliptin or Glimepiride in Patients With Type 2 Diabetes Inadequately Controlled With Metformin Monotherapy
OBJECTIVE - To determine if the dipeptidyl peptidase-4 inhibitor vildagliptin more effectively inhibits glucagon levels than the sulfonylurea glimepiride during a meal. RESEARCH DESIGN AND METHODS - Glucagon responses to a standard meal were measured at baseline and study end point (mean 1.8 years) in a trial evaluating add-on therapy to metformin with 50 mg vildagliptin bid. compared with glimepiride up to 6 mg q.d. in type 2 diabetes (baseline MC 7.3 +/- 0.6%). RESULTS - A1C and prandial glucose area under the curve (AUC)(0-2 h) were reduced similarly in both groups, whereas prandial insulin AUC(0-2 h) increased to a greater extent by glimepiride. Prandial glucagon AUC(0-2 h) (baseline 66.6 +/- 2.3 pmol . h(-1) . l(-1)) decreased by 3.4 +/- 1.6 pmol . h(-1) . l(-1) by vildagliptin (n = 137) and increased by 3.8 +/- 1.7 pmol . h(-1) . l(-1) by glimepiride (n = 121). The between-group difference was 7.3 +/- 2.1 pmol . h(-1) . l(-1) (P < 0.001). CONCLUSIONS - Vildagliptin therapy but not glimepiride improves postprandial a-cell function, which persists for at least 2 years
Experimental L-band SST satellite communications/surveillance terminal study. Volume 3 - Communications/surveillance analysis
Analysis of surveillance and communications functions of L band air traffic control satellite syste
Children's suggestibility in relation to their understanding about sources of knowledge
In the experiments reported here, children chose either to maintain their initial belief about an object's identity or to accept the experimenter's contradicting suggestion. Both 3ā to 4āyearāolds and 4ā to 5āyearāolds were good at accepting the suggestion only when the experimenter was better informed than they were (implicit source monitoring). They were less accurate at recalling both their own and the experimenter's information access (explicit recall of experience), though they performed well above chance. Children were least accurate at reporting whether their final belief was based on what they were told or on what they experienced directly (explicit source monitoring). Contrasting results emerged when children decided between contradictory suggestions from two differentially informed adults: Threeā to 4āyearāolds were more accurate at reporting the knowledge source of the adult they believed than at deciding which suggestion was reliable. Decision making in this observation task may require reflective understanding akin to that required for explicit source judgments when the child participates in the task
Fractal Dimensions in Perceptual Color Space: A Comparison Study Using Jackson Pollock's Art
The fractal dimensions of color-specific paint patterns in various Jackson
Pollock paintings are calculated using a filtering process which models
perceptual response to color differences (\Lab color space). The advantage of
the \Lab space filtering method over traditional RGB spaces is that the
former is a perceptually-uniform (metric) space, leading to a more consistent
definition of ``perceptually different'' colors. It is determined that the RGB
filtering method underestimates the perceived fractal dimension of lighter
colored patterns but not of darker ones, if the same selection criteria is
applied to each. Implications of the findings to Fechner's 'Principle of the
Aesthetic Middle' and Berlyne's work on perception of complexity are discussed.Comment: 21 pp LaTeX; two postscript figure
Sulfur isotope fractionation during oxidation of sulfur dioxide: gas-phase oxidation by OH radicals and aqueous oxidation by H2O2, O3 and iron catalysis
The oxidation of SO[subscript 2] to sulfate is a key reaction in determining the role of sulfate in the environment through its effect on aerosol size distribution and composition. Sulfur isotope analysis has been used to investigate sources and chemical processes of sulfur dioxide and sulfate in the atmosphere, however interpretation of measured sulfur isotope ratios is challenging due to a lack of reliable information on the isotopic fractionation involved in major transformation pathways. This paper presents laboratory measurements of the fractionation factors for the major atmospheric oxidation reactions for SO2: Gas-phase oxidation by OH radicals, and aqueous oxidation by H[subscript 2]O[subscript 2], O[subscript 3] and a radical chain reaction initiated by iron. The measured fractionation factor for [superscript 34]S/[superscript 32]S during the gas-phase reaction is Ī±[subscript OH] = (1.0089Ā±0.0007)ā((4Ā±5)Ć10[subscript ā5]) T(Ā°C). The measured fractionation factor for [superscript 34]S/[superscript 32]S during aqueous oxidation by H[subscript 2]O[subscript 2] or O[subscript 3] is Ī±[subscript aq] = (1.0167Ā±0.0019)ā((8.7Ā±3.5) Ć10[superscript ā5])T(Ā°C). The observed fractionation during oxidation by H2O2 and O3 appeared to be controlled primarily by protonation and acid-base equilibria of S(IV) in solution, which is the reason that there is no significant difference between the fractionation produced by the two oxidants within the experimental error. The isotopic fractionation factor from a radical chain reaction in solution catalysed by iron is Ī±Fe = (0.9894Ā±0.0043) at 19 Ā°C for [superscript 34]S/[superscript 32]S. Fractionation was mass-dependent with regards to 33S/32S for all the reactions investigated. The radical chain reaction mechanism was the only measured reaction that had a faster rate for the light isotopes. The results presented in this study will be particularly useful to determine the importance of the transition metal-catalysed oxidation pathway compared to other oxidation pathways, but other main oxidation pathways can not be distinguished based on stable sulfur isotope measurements alone
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