Thermal evolution and structure models of the transiting super-Earth GJ 1214b

The planet GJ 1214b is the second known super-Earth with a measured mass and radius. Orbiting a quiet M-star, it receives considerably less mass-loss driving X-ray and UV radiation than CoRoT-7b, so that the interior may be quite dissimilar in composition, including the possibility of a large fraction of water. We model the interior of GJ 1214b assuming a two-layer (envelope+rock core) structure where the envelope material is either H/He, pure water, or a mixture of H/He and H2O. Within this framework we perform models of the thermal evolution and contraction of the planet. We discuss possible compositions that are consistent with Mp=6.55 ME, Rp=2.678 RE, an age tau=3-10 Gyr, and the irradiation level of the atmosphere. These conditions require that if water exists in the interior, it must remain in a fluid state, with important consequences for magnetic field generation. These conditions also require the atmosphere to have a deep isothermal region extending down to 80-800 bar, depending on composition. Our results bolster the suggestion of a metal-enriched H/He atmosphere for the planet, as we find water-world models that lack an H/He atmosphere to require an implausibly large water-to-rock ratio of more than 6:1. We instead favor a H/He/H2O envelope with high water mass fraction (~0.5-0.85), similar to recent models of the deep envelope of Uranus and Neptune. Even with these high water mass fractions in the H/He envelope, generally the bulk composition of the planet can have subsolar water:rock ratios. Dry, water-enriched, and pure water envelope models differ to an observationally significant level in their tidal Love numbers k2 of respectively ~0.018, 0.15, and 0.7.Comment: 11 pages, 6 figures, 1 table, accepted to Ap

Verification of a localization criterion for several disordered media

We analytically compute a localization criterion in double scattering approximation for a set of dielectric spheres or perfectly conducting disks uniformly distributed in a spatial volume which can be either spherical or layered. For every disordered medium, we numerically investigate a localization criterion, and examine the influence of the system parameters on the wavelength localization domains.Comment: 30 pages, LateX, amstex, revtex styles, 20 figure

Outcomes and challenges in the management of gestational trophoblastic disease in a tertiary institution in Nigeria

Context: Gestational Trophoblastic Diseases are a spectrum of interrelated diseases disorders that arise from abnormal pregnancy and are characterized by excessive elevation of Human Chorionic Gonadotrophins. They include both benign and malignant forms; hydatidiform mole, Invasive mole, Placental Site Trophoblastic (PSTT) tumour and Choriocarcinoma.Objective: The objective of this study was to present the outcomes and challenges encountered in the management of GTDs in a tertiary centre in South-western part of Nigeria.Study Design, Setting and Subjects: This was a retrospective study of the cases of gestational trophoblastic disease managed at Obafemi Awolowo University Teaching hospitals complex, Ile Ife between 2009 and 2013. Data were retrieved from the case records and telephone calls were put across the patients to enquire about the state of health of the patients. Data was analysed using SPSS version 20.Main Outcome Measures: The main outcome measures were the incidence of GTDs, outcomes and challenges encountered in the management of patients with gestational trophoblastic disease.Results: A total of 27 women were managed for GTDs; 22 had hydatidiform moles and 5 were managed for choriocarcinoma. The mean age of the patients was 31.9 years SD 6.94, mean parity 2 SD 1.53; mean duration of amenorrhoea was 15.7 weeks SD 4.92. The most common presenting symptom was vaginal bleeding in 81.5% of cases. Non-adherence to prescribed treatment was high as over half of the patients with molar pregnancy was lost to follow up after molar evacuation. Mortality was also high among patients with GTDs as 60% of the patients with choriocarcinoma died during treatment

An assessment report on an immunization clinic located in a tertiary institution in Ibadan

Objectives: The aims of the assessment report were to appraise immunization system components and review vaccination coverage between January 2007 and December 2011 at the University College Hospital (UCH) immunization clinic.Methods: The immunization clinic has an annual target population of 997 (for children < one year of age) and 1246 (for pregnant women), which were used in this assessment. The data collection method used included; Key informant - interview, administration of a semi-structured  questionnaire, records review and observations during immunization sessions.Results: The UCH immunization clinic mainly offers fixed sessions and only provides outreach services when there is a need, such as during outbreaks. However, there are no records of vaccinepreventable diseases being  monitored. The coverage rate for nearly all of the vaccines was greater than 100% of the estimated target population for the hospital. Except for the coverage rate of Bacille Calmette Guerin (BCG) vaccine, which peaked in 2011, other vaccines’ coverage peaked in 2009, after which therewas a decline. The highest dropout rate was recorded in 2007, while the rates between 2009 and 2010 were <10%, but the BCG and measles drop out rates were >10% for the 5-year period. For the adult immunizations, yellow fever recorded the highest coverage rate, while the lowest rate was recorded for tetanus toxoid dose 5 (TT5). The vaccines that were most often in short supply included Diphtheria-pertusis-tetanus, Hepatitis B,yellow fever, oral polio, and cerebrospinal meningitis vaccines. Although good-quality supplies, equipment and consumables were observed, there was no inventory of these items. There were evident interpersonal communication and community mobilization as well as capacity building for staff.Conclusion: The assessment showed there was progress in the provision and administration of immunization based on available resources. There is, however, the need to improve documentation of clinic activities

Kondo effect in a one dimensional d-wave superconductor

We derive a solvable resonant-level type model, to describe an impurity spin coupled to zero-energy bound states localized at the edge of a one dimensional d-wave superconductor. This results in a two-channel Kondo effect with a quite unusual low-temperature thermodynamics. For instance, the local impurity susceptibility yields a finite maximum at zero temperature (but no logarithmic-divergence) due to the splitting of the impurity in two Majorana fermions. Moreover, we make comparisons with the Kondo effect occurring in a two dimensional d-wave superconductor.Comment: 9 pages, final version; To be published in Europhysics Letter

Acute-on-chronic liver failure in cirrhosis

The definition of acute-on-chronic liver failure (ACLF) remains contested. In Europe and North America, the term is generally applied according to the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) Consortium guidelines, which defines this condition as a syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure and high short-term mortality. One-third of patients who are hospitalized for acute decompensation present with ACLF at admission or develop the syndrome during hospitalization. ACLF frequently occurs in a closed temporal relationship to a precipitating event, such as bacterial infection or acute alcoholic, drug-induced or viral hepatitis. However, no precipitating event can be identified in approximately 40% of patients. The mechanisms of ACLF involve systemic inflammation due to infections, acute liver damage and, in cases without precipitating events, probably intestinal translocation of bacteria or bacterial products. ACLF is graded into three stages (ACLF grades 1–3) on the basis of the number of organ failures, with higher grades associated with increased mortality. Liver and renal failures are the most common organ failures, followed by coagulation, brain, circulatory and respiratory failure. The 28-day mortality rate associated with ACLF is 30%. Depending on the grade, ACLF can be reversed using standard therapy in only 16–51% of patients, leaving a considerable proportion of patients with ACLF that remains steady or progresses. Liver transplantation in selected patients with ACLF grade 2 and ACLF grade 3 increases the 6-month survival from 10% to 80%

Acute-on-Chronic Liver Failure: Definition, Diagnosis, and Clinical Characteristics

Acute-on-chronic liver failure (ACLF) is a recently recognized syndrome in cirrhosis characterized by acute decompensation (AD), organ failure(s), and high short-term mortality. Organ failure(s) is defined by the Chronic Liver Failure-Sequential Organ Failure (CLIF-SOFA) score or by its simplified version Chronic Liver Failure-Organ Failure Assessment (CLIF-OF) score. They include six types of organ failure: liver, renal, coagulation, cerebral, respiratory, and circulatory. One third of patients hospitalized with AD present with ACLF at admission or develop ACLF during hospitalization. Acute-on-chronic liver failure frequently occurs in a closed relationship to a precipitating event. According to the number of organ failures, ACLF is graded into three stages: ACLF-1 = single renal failure or single nonrenal organ failure if associated with renal dysfunction and/or cerebral dysfunction; ACLF-2 = two organ failures; and ACLF-3 = three to six organ failures, with increasing 28-day mortality rate (from 23%–74%). Acute-on-chronic liver failure may develop at any phase during the clinical course of the disease. Patients without prior AD develop a severe form of ACLF

Accuracy of magnetic resonance studies in the detection of chondral and labral lesions in femoroacetabular impingement : systematic review and meta-analysis

Background: Several types of Magnetic resonance imaging (MRI) are commonly used in imaging of femoroacetabular impingement (FAI), however till now there are no clear protocols and recommendations for each type. The aim of this meta-analysis is to detect the accuracy of conventional magnetic resonance imaging (cMRI), direct magnetic resonance arthrography (dMRA) and indirect magnetic resonance arthrography (iMRA) in the diagnosis of chondral and labral lesions in femoroacetabular impingement (FAI). Methods: A literature search was finalized on the 17th of May 2016 to collect all studies identifying the accuracy of cMRI, dMRA and iMRA in diagnosing chondral and labral lesions associated with FAI using surgical results (arthroscopic or open) as a reference test. Pooled sensitivity and specificity with 95% confidence intervals using a random-effects meta-analysis for MRI, dMRA and iMRA were calculated also area under receiver operating characteristic (ROC) curve (AUC) was retrieved whenever possible where AUC is equivocal to diagnostic accuracy. Results: The search yielded 192 publications which were reviewed according inclusion and exclusion criteria then 21 studies fulfilled the eligibility criteria for the qualitative analysis with a total number of 828 cases, lastly 12 studies were included in the quantitative meta-analysis. Meta-analysis showed that as regard labral lesions the pooled sensitivity, specificity and AUC for cMRI were 0.864, 0.833 and 0.88 and for dMRA were 0.91, 0.58 and 0.92. While in chondral lesions the pooled sensitivity, specificity and AUC for cMRI were 0.76, 0.72 and 0.75 and for dMRA were 0.75, 0.79 and 0.83, while for iMRA were sensitivity of 0.722 and specificity of 0.917. Conclusions: The present meta-analysis showed that the diagnostic test accuracy was superior for dMRA when compared with cMRI for detection of labral and chondral lesions. The diagnostic test accuracy was superior for labral lesions when compared with chondral lesions in both cMRI and dMRA. Promising results are obtained concerning iMRA but further studies still needed to fully assess its diagnostic accuracy

Icebergs in the North Atlantic: Modelling circulation changes and glacio-marine deposition

In order to investigate meltwater events in the North Atlantic, a simple iceberg generation, drift, and melting routine was implemented in a high-resolution OGCM. Starting from the modelled last glacial state, every 25th day cylindrical model icebergs 300 meters high were released at 32 specific points along the coasts. Icebergs launched at the Barents Shelf margin spread a light meltwater lid over the Norwegian and Greenland Seas, shutting down the deep convection and the anti-clockwise circulation in this area. Due to the constraining ocean circulation, the icebergs produce a tongue of relatively cold and fresh water extending eastward from Hudson Strait that must develop at this location, regardless of iceberg origin. From the total amount of freshwater inferred by the icebergs, the thickness of the deposited IRD could be calculated in dependance of iceberg sediment concentration. In this way, typical extent and thickness of Heinrich layers could be reproduced, running the model for 250 years of steady state with constant iceberg meltwater inflow

Modeling Supply Networks and Business Cycles as Unstable Transport Phenomena

Physical concepts developed to describe instabilities in traffic flows can be generalized in a way that allows one to understand the well-known instability of supply chains (the so-called ``bullwhip effect''). That is, small variations in the consumption rate can cause large variations in the production rate of companies generating the requested product. Interestingly, the resulting oscillations have characteristic frequencies which are considerably lower than the variations in the consumption rate. This suggests that instabilities of supply chains may be the reason for the existence of business cycles. At the same time, we establish some link to queuing theory and between micro- and macroeconomics.Comment: For related work see http://www.helbing.or