238 research outputs found
Delays in diagnosis of young women with symptomatic cervical cancer in England: an interview-based study
Background: Diagnosis may be delayed in young females with cervical cancer because of a failure to recognise symptoms. Aim: To examine the extent and determinants of delays in diagnosis of young females with symptomatic cervical cancer. Design and setting: A national descriptive study of time from symptoms to diagnosis of cervical cancer and risk factors for delay in diagnosis at all hospitals diagnosing cervical cancer in England. Method: One-hundred and twenty-eight patients <30 years with a recent diagnosis of cervical cancer were interviewed. Patient delay was defined as ?3 months from symptom onset to first presentation and provider delay as ? 3 months from first presentation to diagnosis. Results: Forty (31%) patients had presented symptomatically: 11 (28%) delayed presentation. Patient delay was more common in patients <25 than patients aged 25–29 (40% versus 15%, P = 0.16). Vaginal discharge was more common among patients who delayed presentation than those who did not; many reported not recognising this as a possible cancer symptom. Provider delay was reported by 24/40 (60%); in some no report was found in primary care records of a visual inspection of the cervix and some did not re-attend after the first presentation for several months. Gynaecological symptoms were common (84%) among patients who presented via screening. Conclusions: Young females with cervical cancer frequently delay presentation, and not recognising symptoms as serious may increase the risk of delay. Delay in diagnosis after first presentation is also common. There is some evidence that UK guidelines for managing young females with abnormal bleeding are not being followed
Host Galaxy Evolution in Radio-Loud AGN
We investigate the luminosity evolution of the host galaxies of radio-loud
AGN through Hubble Space Telescope imaging of 72 BL Lac objects, including new
STIS imaging of nine z > 0.6 BL Lacs. With their intrinsically low accretion
rates and their strongly beamed jets, BL Lacs provide a unique opportunity to
probe host galaxy evolution independent of the biases and ambiguities implicit
in quasar studies. We find that the host galaxies of BL Lacs evolve strongly,
consistent with passive evolution from a period of active star formation in the
range 0.5 <~ z <~ 2.5, and inconsistent with either passive evolution from a
high formation redshift or a non-evolving population. This evolution is broadly
consistent with that observed in the hosts of other radio-loud AGN, and
inconsistent with the flatter luminosity evolution of quiescent early types and
radio-quiet hosts. This indicates that active star formation, and hence galaxy
interactions, are associated with the formation for radio-loud AGN, and that
these host galaxies preferentially accrete less material after their formation
epoch than galaxies without powerful radio jets. We discuss possible
explanations for the link between merger history and the incidence of a radio
jet.Comment: 37 pages, 8 figures, accepted for publication in ApJ, for full PDF
incl. figures see
http://www.ph.unimelb.edu.au/~modowd/papers/odowdurry2005.pd
The HST Survey of BL Lacertae Objects. II. Host Galaxies
We have used the HST WFPC2 camera to survey 132 BL Lac objects comprising
seven complete radio-, X-ray-, and optically-selected samples. We obtained
useful images for 110 targets spanning the redshift range 0 < z < 1.3. In two
thirds of the BL Lac images, host galaxies are detected, including nearly all
for z < 0.5 (58 of 63). The highest redshift host galaxy detected is in a BL
Lac object at z=0.664. In 58 of the 72 resolved host galaxies, a de Vaucouleurs
profile is significantly preferred, at >99% confidence, over a pure exponential
disk; the two fits are comparable in the remaining 14 cases. These results
limit the number of disk systems to at most 8% of BL Lacs (at 99% confidence),
and are consistent with all BL~Lac host galaxies being ellipticals. The
detected host galaxies are luminous ellipticals with a median absolute
K-corrected magnitude of M_R= -23.7 +- 0.6 mag, at least one magnitude brighter
than M* and comparable to brightest cluster galaxies. The galaxy morphologies
are generally smooth and undisturbed, with small or negligible ellipticities
(<0.2). There is no correlation between host galaxy and observed nuclear
magnitude or estimated jet power corrected for beaming. If black hole mass is
correlated linearly with bulge mass in general, this implies a large range in
Eddington ratio. Present data strongly support the unification picture with FR
I galaxies constituting the bulk of the parent population of BL Lac objects.Comment: Accepted for publication on ApJ. 38 pages, 8 figure
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An overview of the Lagrangian experiments undertaken during the North Atlantic regional Aerosol Characterisation Experiment (ACE-2)
One of the primary aims of the North Atlantic regional Aerosol Characterisation Experiment
(ACE-2) was to quantify the physical and chemical processes affecting the evolution of the
major aerosol types over the North Atlantic. The best, practical way of doing this is in a
Lagrangian framework where a parcel of air is sampled over several tens of hours and its
physical and chemical properties are intensively measured. During the intensive observational
phase of ACE-2, between 15 June 1997 and 24 July 1997, 3 cloudy Lagrangian experiments
and 3 cloud-free, Lagrangian experiments were undertaken between the south west tip of the
Iberian Peninsula and the Canary Islands. This paper gives an overview of the aims and logistics
of all of the Lagrangian experiments and compares and contrasts them to provide a framework
for the more focused Lagrangian papers in this issue and future process modelling studies and
parametrisation development. The characteristics of the cloudy Lagrangian experiments were
remarkably different, enabling a wide range of different physical and chemical processes to be
studied. In the 1st Lagrangian, a clean maritime air mass was sampled in which salt particle
production, due to increased wind speed, dominated the change in the accumulation mode
concentrations. In the 2nd Lagrangian, extensive cloud cover resulted in cloud processing of
the aerosol in a polluted air mass, and entrainment of air from the free troposphere influenced
the overall decrease in aerosol concentrations in the marine boundary layer (MBL). Very little
change in aerosol characteristics was measured in the 3rd Lagrangian, where the pollution in
the MBL was continually being topped up by entraining air from a residual continental boundary
layer (CBL) above. From the analysis of all the Lagrangian experiments, it has been possible
to formulate, and present here, a generalised description of a European continental outbreak
of pollution over the sub-tropical North Atlantic
HST/COS Observations of the Ly alpha Forest toward the BL Lac Object 1ES1553+113
We present new far-ultraviolet spectra from the Cosmic Origins Spectrograph
(HST/COS) of the BL Lac object 1ES1553+113 covering the wavelength range
1135-1795 A. The data show a smooth continuum with a wealth of narrow
absorption features arising in the ISM and IGM. These features include 41 Lya
absorbers at 0<z<0.43, fourteen of which are detected in multiple Lyman lines
and six in one or more metal lines. We analyze a metal-rich triplet of Lya
absorbers at z=0.188 in which OVI, NV, and CIII absorption is detected. Silicon
ions (SiIII/IV) are not detected to fairly strong upper limits, and we use the
measured SiIII/CIII upper limit to derive an abundance limit [C/Si]>0.6 for the
strongest component of the absorber complex. Galaxy redshift surveys show a
number of massive galaxies at approximately the same redshift as this
absorption complex, suggesting that it arises in a large-scale galaxy filament.
As one of the brightest extragalactic X-ray and gamma-ray sources, 1ES1553+113
is of great interest to the high-energy astrophysics community. With no
intrinsic emission or absorption features, 1ES1553+113 has no direct redshift
determination. We use intervening Lya absorbers to place a direct limit on the
redshift: z_em>0.395 based on a confirmed Lya+OVI absorber and z_em>0.433 based
on a single-line detection of Lya. COS/FUV data are only sensitive to Lya
absorbers at z<0.47, but we present statistical arguments that z_em<0.58 based
on the non-detection of any Lyb absorbers at z>0.4.Comment: ApJ submitted: 11 pages, 7 figure
Promoting help-seeking in response to symptoms amongst primary care patients at high risk of lung cancer: a mixed method study
Background: Lung cancer symptoms are vague and difficult to detect. Interventions are needed to promote early diagnosis, however health services are already pressurised. This study explored symptomology and help-seeking behaviours of primary care patients at ‘high-risk’ of lung cancer (≥50 years old, recent smoking history), to inform targeted interventions.
Methods: Mixed method study with patients at eight general practitioner (GP) practices across south England. Study incorporated: postal symptom questionnaire; clinical records review of participant consultation behaviour 12 months pre- and post-questionnaire; qualitative participant interviews (n = 38) with a purposive sample.
Results: A small, clinically relevant group (n = 61/908, 6.7%) of primary care patients was identified who, despite reporting potential symptoms of lung cancer in questionnaires, had not consulted a GP ≥12 months. Of nine symptoms associated with lung cancer, 53.4% (629/1172) of total respondents reported ≥1, and 35% (411/1172) reported ≥2. Most participants (77.3%, n = 686/908) had comorbid conditions; 47.8%, (n = 414/908) associated with chest and respiratory symptoms. Participant consulting behaviour significantly increased in the 3-month period following questionnaire completion compared with the previous 3-month period (p = .002), indicating questionnaires impacted upon consulting behaviour. Symptomatic non-consulters were predominantly younger, employed, with higher multiple deprivation scores than their GP practice mean. Of symptomatic non-consulters, 30% (18/61) consulted ≤1 month post-questionnaire, with comorbidities subsequently diagnosed for five participants. Interviews (n = 39) indicated three overarching differences between the views of consulting and non-consulting participants: concern over wasting their own as well as GP time; high tolerance threshold for symptoms; a greater tendency to self-manage symptoms.
Conclusions: This first study to examine symptoms and consulting behaviour amongst a primary care population at ‘high- risk’ of lung cancer, found symptomatic patients who rarely consult GPs, might respond to a targeted symptom elicitation intervention. Such GP-based interventions may promote early diagnosis of lung cancer or other comorbidities, without burdening already pressurised services
Conversion of Iodide to Hypoiodous Acid and Iodine in Aqueous Microdroplets Exposed to Ozone
Halides are incorporated into aerosol sea spray, where they start the catalytic destruction of ozone (O3) over the oceans and affect the global troposphere. Two intriguing environmental problems undergoing continuous research are (1) to understand how reactive gas phase molecular halogens are directly produced from inorganic halides exposed to O3 and (2) to constrain the environmental factors that control this interfacial process. This paper presents a laboratory study of the reaction of O3 at variable iodide (I–) concentration (0.010–100 μM) for solutions aerosolized at 25 °C, which reveal remarkable differences in the reaction intermediates and products expected in sea spray for low tropospheric [O3]. The ultrafast oxidation of I– by O3 at the air–water interface of microdroplets is evidenced by the appearance of hypoiodous acid (HIO), iodite (IO2–), iodate (IO3–), triiodide (I3–), and molecular iodine (I2). Mass spectrometry measurements reveal an enhancement (up to 28%) in the dissolution of gaseous O3 at the gas–liquid interface when increasing the concentration of NaI or NaBr from 0.010 to 100 μM. The production of iodine species such as HIO and I2 from NaI aerosolized solutions exposed to 50 ppbv O3 can occur at the air–water interface of sea spray, followed by their transfer to the gas-phase, where they contribute to the loss of tropospheric ozone
Daily functioning and self-management in patients with chronic low back pain after an intensive cognitive behavioral programme for pain management
Chronic low back pain (CLBP) is associated with persistent or recurrent disability which results in high costs for society. Cognitive behavioral treatments produce clinically relevant benefits for patients with CLBP. Nevertheless, no clear evidence for the most appropriate intervention is yet available. The purpose of this study is to evaluate the mid-term effects of treatment in a cohort of patients with CLBP participating in an intensive pain management programme. The programme provided by RealHealth-Netherlands is based on cognitive behavioral principles and executed in collaboration with orthopedic surgeons. Main outcome parameters were daily functioning (Roland and Morris Disability Questionnaire and Oswestry Disability Questionnaire), self-efficacy (Pain Self-Efficacy Questionnaire) and quality of life (Short Form 36 Physical Component Score). All parameters were measured at baseline, last day of residential programme and at 1 and 12 months follow-up. Repeated measures analysis was applied to examine changes over time. Clinical relevance was examined using minimal clinical important differences (MCID) estimates for main outcomes. To compare results with literature effect sizes (Cohen’s d) and Standardized Morbidity Ratios (SMR) were determined. 107 patients with CLBP participated in this programme. Mean scores on outcome measures showed a similar pattern: improvement after residential programme and maintenance of results over time. Effect sizes were 0.9 for functioning, 0.8 for self-efficacy and 1.3 for physical functioning related quality of life. Clinical relevancy: 79% reached MCID on functioning, 53% on self-efficacy and 80% on quality of life. Study results on functioning were found to be 36% better and 2% worse when related to previous research on, respectively, rehabilitation programmes and spinal surgery for similar conditions (SMR 136 and 98%, respectively). The participants of this evidence-based programme learned to manage CLBP, improved in daily functioning and quality of life. The study results are meaningful and comparable with results of spinal surgery and even better than results from less intensive rehabilitation programmes
On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes
The sensitivity of a search for sources of TeV neutrinos can be improved by
grouping potential sources together into generic classes in a procedure that is
known as source stacking. In this paper, we define catalogs of Active Galactic
Nuclei (AGN) and use them to perform a source stacking analysis. The grouping
of AGN into classes is done in two steps: first, AGN classes are defined, then,
sources to be stacked are selected assuming that a potential neutrino flux is
linearly correlated with the photon luminosity in a certain energy band (radio,
IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino
production in AGN, this correlation is motivated by hadronic AGN models, as
briefly reviewed in this paper.
The source stacking search for neutrinos from generic AGN classes is
illustrated using the data collected by the AMANDA-II high energy neutrino
detector during the year 2000. No significant excess for any of the suggested
groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic
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