Neutrino-nucleon scattering rate in the relativistic random phase approximation

The in-medium modification to the neutrino-nucleon scattering rate is calculated in the relativistic random phase approximation in the framework of a hadronic meson exchange model, in view of applications to neutrino transport in supernovae and protoneutron starsComment: 4 pages, 2 figures, to appear in the Proceedings of the PANIC02 conference, 30 sept - 4 oct 2002, Osaka, Japa

Reactivity of Acyclic (pentadienyl)iron(1+) Cations with Phosphonate Stabilized Nucleophiles: Application to the Synthesis of Oxygenated Metabolites of Carvone

The addition of phosphonate stabilized carbon nucleophiles to acyclic (pentadienyl)iron(1+) cations proceeds predominantly at an internal carbon to afford (pentenediyl)iron complexes. Those complexes bearing an electron withdrawing group at the σ-bound carbon (i.e., 13/14) are stable and isolable, while complexes which do not contain an electron withdrawing group at the σ-bound carbon undergo CO insertion, reductive elimination and conjugation of the double bond to afford cyclohexenone products (21/22). Deprotonation of the phosphonate 13/14 or 21 and reaction with paraformaldehyde affords the olefinated products. This methodology was utilized to prepare oxygenated carvone metabolites (±)-25 and (±)-26

‘It’s too late’. Is it really? Considerations for amblyopia treatment in older children

In recent years, media coverage has demonstrated instances in which families of children aged 7 and older, newly diagnosed with strabismic and/or anisometropic amblyopia through community eyecare services, were told it was ‘too late’ for their child to effectively respond to conventional amblyopia treatment (occlusion or atropine penalisation). Formal guidance pertaining to binocular vision anomalies from eyecare professional bodies does not specifically make reference to a child’s age, beyond stating the importance of early diagnosis and treatment of strabismus/amblyopia. However, there have been many changes in the way we view the recovery period for amblyopia, and it is well demonstrated both within literature and clinical practice that conventional treatment can improve amblyopic eye visual acuity in children beyond the age of 7 years. The occurrence of these media described cases within the community eyecare sphere would suggest it is worthwhile revisiting the literature on the subject of amblyopia treatment in older children (aged 7+ years), to address misconceptions and place in the spotlight current considerations facing clinicians when treating newly diagnosed amblyopia within this age group. This perspective review provides an evidence-based update covering the various considerations associated with treatment of amblyopia in older children, along with recent amblyopia treatment advances that could have an impact on treatment prospects for this patient group. Considerations include the risks, benefits and efficacy of treating newly diagnosed amblyopia in older children, monitoring density of suppression to mitigate intractable diplopia risk, and recent findings regarding binocular treatments for amblyopia

The Gas Consumption History to z ~ 4

Using the observations of the star formation rate and HI densities to z ~ 4, with measurements of the Molecular Gas Depletion Rate (MGDR) and local density of H_2 at z = 0, we derive the history of the gas consumption by star formation to z ~ 4. We find that closed-box models in which H_2 is not replenished by HI require improbably large increases in rho(H_2) and a decrease in the MGDR with lookback time that is inconsistent with observations. Allowing the H_2 used in star formation to be replenished by HI does not alleviate the problem because observations show that there is very little evolution of rho(HI) from z = 0 to z = 4. We show that to be consistent with observational constraints, star formation on cosmic timescales must be fueled by intergalactic ionized gas, which may come from either accretion of gas through cold (but ionized) flows or from ionized gas associated with accretion of dark matter halos. We constrain the rate at which the extraglactic ionized gas must be converted into HI and ultimately into H_2. The ionized gas inflow rate roughly traces the SFRD: about 1 - 2 x 10^8 M_sun Gyr^-1 Mpc^-3 from z ~ 1 - 4, decreasing by about an order of magnitude from z=1 to z=0 with details depending largely on MGDR(t). All models considered require the volume averaged density of rho(H_2) to increase by a factor of 1.5 - 10 to z ~ 1.5 over the currently measured value. Because the molecular gas must reside in galaxies, it implies that galaxies at high z must, on average, be more molecule rich than they are at the present epoch, which is consistent with observations. These quantitative results, derived solely from observations, agree well with cosmological simulations.Comment: 11 pages, 6 figures. Accepted for publication in the Astrophysical Journal

Primary enucleation for group D retinoblastoma in the era of systemic and targeted chemotherapy: the price of retaining an eye

BACKGROUND: Chemotherapy is increasingly used as primary treatment for group D retinoblastoma, whereas primary enucleation is considered to have a diminishing role. This study aimed to compare the management course, including number of examinations under anaesthesia (EUAs), of group D patients treated by enucleation versus chemotherapy. METHODS: A retrospective analysis of 92 group D patients, of which 40 (37 unilateral) underwent primary enucleation and 52 (17 unilateral) were treated with intravenous chemotherapy. Number of EUAs was compared between the treatment groups with respect to the whole cohort, using univariate and multivariate analysis, and to unilateral cases only. RESULTS: Patients were followed up for a median of 61 months (mean: 66, range: 14-156), in which time primary enucleated patients had on average seven EUAs and chemotherapy-treated patients 21 EUAs (p<0.001). Chemotherapy, young age, bilateral disease, multifocal tumours, familial and germline retinoblastoma were found on univariate analysis to correlate with increased number of EUAs (p≤0.019). On multivariate analysis, however, only treatment type and presentation age were found significant (p≤0.001). On subanalysis of the unilateral cases, patients undergoing primary enucleation had in average seven EUAs, as compared with 16 in the chemotherapy group (p<0.001). Of the 55 unilateral-presenting patients, a new tumour developed in the fellow eye only in a single familial case. CONCLUSION: Group D patients' families should be counselled regarding the significant difference in number of EUAs following primary enucleation versus chemotherapy when deciding on a treatment strategy. In this regard, primary enucleation would be most beneficial for older patients with unilateral disease

Star-galaxy separation by far-infrared color-color diagrams for the AKARI FIS All-Sky Survey (Bright Source Catalogue Version beta-1)

To separate stars and galaxies in the far infrared AKARI All-Sky Survey data, we have selected a sample with the complete color information available in the low extinction regions of the sky and constructed color-color plots for these data. We looked for the method to separate stars and galaxies using the color information. We performed an extensive search for the counterparts of these selected All-Sky Survey sources in the NED and SIMBAD databases. Among 5176 objects, we found 4272 galaxies, 382 other extragalactic objects, 349 Milky Way stars, 50 other Galactic objects, and 101 sources detected before in various wavelengths but of an unknown origin. 22 sources were left unidentified. Then, we checked colors of stars and galaxies in the far-infrared flux-color and color-color plots. In the resulting diagrams, stars form two clearly separated clouds. One of them is easy to be distinguished from galaxies and allows for a simple method of excluding a large part of stars using the far-infrared data. The other smaller branch, overplotting galaxies, consists of stars known to have an infrared excess, like Vega and some fainter stars discovered by IRAS or 2MASS. The color properties of these objects in any case make them very difficult to distinguish from galaxies. We conclude that the FIR color-color diagrams allow for a high-quality star-galaxy separation. With the proposed simple method we can select more that 95 % of galaxies rejecting at least 80 % of stars.Comment: 20 pages, 41 figures, "Astronomy & Astrophysics", accepted, to appear in the AKARI special issu

Primary intravenous chemotherapy for group D retinoblastoma: a 13-year retrospective analysis.

BACKGROUND: Eye salvage rate for group D retinoblastoma using intravenous chemotherapy (IVC) as a primary modality is <50%. To report on 13 years' experience with the use of primary IVC for group D retinoblastoma. METHODS: A retrospective analysis of 64 group D eyes (52 patients) treated with primary IVC, from 2002 to 2014. RESULTS: The median age at presentation was 11.0 months (mean: 18.6, range: 0.6-144.0), 35 (67%) patients had bilateral disease, 38 (73%) germline disease and 8 (15%) cases were familial. In addition to IVC, patients received a median number of three treatments (mean: 6, range: 0-24), including thermotherapy/cryotherapy, plaque radiotherapy, intra-ophthalmic artery chemotherapy (IAC) and/or intravitreous chemotherapy. External beam radiotherapy (EBRT) was used in five eyes, all of which were eventually enucleated. In a median follow-up time of 55 months (mean: 64, range: 14-156), 63% of eyes were salvaged. By the Kaplan-Meier survival analysis, globe salvage rate was 83%, 70%, 59% and 45% at 1, 3, 5 and 10 years, respectively. There were no cases of metastatic spread from intraocular retinoblastoma and no deaths. IVC-related adverse events included febrile neutropenia in 21 (40%) patients and anaphylactic reaction to carboplatin in 2 (4%), all conservatively resolved. Of the patients receiving IAC, third and sixth nerve palsies were documented in two (10%) and one (5%) eyes, respectively. CONCLUSIONS: Primary IVC for group D eyes, with adjuvant treatments as required, was found to be a safe and efficient approach, achieving 63% eye salvage rate, no metastatic spread from intraocular retinoblastoma and no deaths. IAC has now replaced EBRT as a successful salvage treatment

Lag time for retinoblastoma in the UK revisited: a retrospective analysis

OBJECTIVES: To explore current delays in diagnosis of retinoblastoma (Rb) and effect on outcome with comparison to a study from the 1990s. SETTING: Primary, secondary, tertiary care: majority from South of England. PARTICIPANTS: A retrospective analysis of 93 new referrals of sporadic (non-familial) Rb to a specialist Rb unit in London, UK from January 2006 to February 2014. PRIMARY AND SECONDARY OUTCOMES: International Intraocular Retinoblastoma Classification, lag times including parental delay and healthcare professional delay, patients requiring enucleation and requirement of adjuvant chemotherapy postenucleation (high-risk Rb). RESULTS: During the study period, 29% presented via accident and emergency (A&E). The median referral time from symptom onset to visiting primary care (PC) was 28 days and PC to ophthalmologist 3 days (range 0-181 days). The median time from local ophthalmologist to the Rb Unit was 6 days (0-33). No significant correlation was found between delay and International Classification of Retinoblastoma grade (p>0.05) or between postenucleation adjuvant chemotherapy and enucleation groups (p>0.05). Less enucleations (60%) are being performed compared with the previous study (81%) (p=0.0015). CONCLUSIONS: Parents are attending A&E more compared with the 1990s and this may reflect the effect of public awareness campaigns. More eyes are being salvaged despite a similar number of children requiring adjuvant chemotherapy. High-risk Rb and Group E eyes do not correlate with increased lag time in the UK. Other determinants such as tumour biology may be more relevant