Exchangeability and sets of desirable gambles

Sets of desirable gambles constitute a quite general type of uncertainty model with an interesting geometrical interpretation. We give a general discussion of such models and their rationality criteria. We study exchangeability assessments for them, and prove counterparts of de Finetti's finite and infinite representation theorems. We show that the finite representation in terms of count vectors has a very nice geometrical interpretation, and that the representation in terms of frequency vectors is tied up with multivariate Bernstein (basis) polynomials. We also lay bare the relationships between the representations of updated exchangeable models, and discuss conservative inference (natural extension) under exchangeability and the extension of exchangeable sequences.Comment: 40 page

Nevirapine and efavirenz elicit different changes in lipid profiles in antiretroviral-therapy-naive patients infected with HIV-1

Patients infected with HIV-1 initiating antiretroviral therapy (ART) containing a non-nucleoside reverse transcriptase inhibitor (NNRTI) show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analyzed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP) and efavirenz (EFV)

Analytic Relations for Magnifications and Time Delays in Gravitational Lenses with Fold and Cusp Configurations

Gravitational lensing provides a unique and powerful probe of the mass distributions of distant galaxies. Four-image lens systems with fold and cusp configurations have two or three bright images near a critical point. Within the framework of singularity theory, we derive analytic relations that are satisfied for a light source that lies a small but finite distance from the astroid caustic of a four-image lens. Using a perturbative expansion of the image positions, we show that the time delay between the close pair of images in a fold lens scales with the cube of the image separation, with a constant of proportionality that depends on a particular third derivative of the lens potential. We also apply our formalism to cusp lenses, where we develop perturbative expressions for the image positions, magnifications and time delays of the images in a cusp triplet. Some of these results were derived previously for a source asymptotically close to a cusp point, but using a simplified form of the lens equation whose validity may be in doubt for sources that lie at astrophysically relevant distances from the caustic. Along with the work of Keeton et al. (2005), this paper demonstrates that perturbation theory plays an important role in theoretical lensing studies.Comment: 10 pages, 3 figures; reference added, minor correction

Nevirapine and Efavirenz Elicit Different Changes in Lipid Profiles in Antiretroviral- Therapy-Naive Patients Infected with HIV-1

BACKGROUND: Patients infected with HIV-1 initiating antiretroviral therapy (ART) containing a non-nucleoside reverse transcriptase inhibitor (NNRTI) show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analysed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP) and efavirenz (EFV). METHODS AND FINDINGS: Prospective analysis of lipids and lipoproteins was performed in patients enrolled in the NVP and EFV treatment groups of the 2NN study who remained on allocated treatment during 48 wk of follow-up. Patients were allocated to NVP (n = 417), or EFV (n = 289) in combination with stavudine and lamivudine. The primary endpoint was percentage change over 48 wk in high-density lipoprotein cholesterol (HDL-c), total cholesterol (TC), TC:HDL-c ratio, non-HDL-c, low-density lipoprotein cholesterol, and triglycerides. The increase of HDL-c was significantly larger for patients receiving NVP (42.5%) than for patients receiving EFV (33.7%; p = 0.036), while the increase in TC was lower (26.9% and 31.1%, respectively; p = 0.073), resulting in a decrease of the TC:HDL-c ratio for patients receiving NVP (−4.1%) and an increase for patients receiving EFV (+5.9%; p < 0.001). The increase of non-HDL-c was smaller for patients receiving NVP (24.7%) than for patients receiving EFV (33.6%; p = 0.007), as were the increases of triglycerides (20.1% and 49.0%, respectively; p < 0.001) and low-density lipoprotein cholesterol (35.0% and 40.0%, respectively; p = 0.378). These differences remained, or even increased, after adjusting for changes in HIV-1 RNA and CD4+ cell levels, indicating an effect of the drugs on lipids over and above that which may be explained by suppression of HIV-1 infection. The increases in HDL-c were of the same order of magnitude as those seen with the use of the investigational HDL-c-increasing drugs. CONCLUSION: NVP-containing ART shows larger increases in HDL-c and decreases in TC:HDL-c ratio than an EFV-containing regimen. Based on these findings, protease-inhibitor-sparing regimens based on non-nucleoside reverse transcriptase inhibitor, particularly those containing NVP, may be expected to result in a reduced risk of coronary heart disease

Side-Payments and the Costs of Conflict

Conflict and competition often impose costs on both winners and losers, and conflicting parties may prefer to resolve the dispute before it occurs. The equilibrium of a conflict game with side-payments predicts that with binding offers, proposers make and responders accept side-payments, generating settlements that strongly favor proposers. When side-payments are non-binding, proposers offer nothing and conflicts always arise. Laboratory experiments confirm that binding side-payments reduce conflicts. However, 30 % of responders reject binding offers, and offers are more egalitarian than predicted. Surprisingly, non-binding side-payments also improve efficiency, although less than binding. With binding side-payments, 87 % of efficiency gains come from avoided conflicts. However, with non-binding side-payments, only 39 % of gains come from avoided conflicts and 61 % from reduced conflict expenditures

Updating the approaches to define susceptibility and resistance to anti-tuberculosis agents: implications for diagnosis and treatment

11 páginas, 2 figuras, 1 tablaInappropriately high breakpoints have resulted in systematic false-susceptible AST results to anti-TB drugs. MIC, PK/PD and clinical outcome data should be combined when setting breakpoints to minimise the emergence and spread of antimicrobial resistance.I. Comas was supported by PID2019-104477RB-I00 from the Spanish Science Ministry and by ERC (CoG 101001038)Peer reviewe

Scrotal swellings and cysts

The typical presentation of scrotal cysts varies between the pediatric and adult populations. While pediatric patients are often brought to urologists for scrotal swelling due to their parents or themselves noticing the lesion, testicular cysts in adults more often present as non-palpable lesions as an incidental finding on ultrasound. The great majority of testicular cysts, paratesticular cysts, and scrotal fluid collections are benign and do not require treatment unless the patient experiences some pain or discomfort due to the cyst. Most scrotal cysts are located in the paratesticular tissue. As an intratesticular mass is considered cancerous until proven otherwise, intratesticular cysts represent a minority of all testicular lesions. Fluid collections may also be found in the scrotum and are benign. Diagnosis of scrotal cysts may be determined via clinical assessment together with imaging, usually with grey-scale or color Doppler ultrasound, with all cysts lacking internal vascularity on Doppler

Neoplastic lesions of scrotum

Testicular neoplasms account for 1–2% of all neoplasms in males and are the most common cancer type found in men ages 15- to 40-years-old. Clinical evaluation of a suspected scrotal neoplasm is initially based on the patient history and physical exam. The most common presentation of testicular cancer involves a painless scrotal mass or swelling, with acute testicular pain present in some cases. Concerning clinical findings should prompt further workup with an ultrasound and serum tumor markers, which can be used to help further narrow down the differential diagnosis. Definitive diagnosis is achieved via histological analysis. Characterization of the testicular tumor type is based on its histological analysis and pathogenesis, as per the most recent 2016 World Health Organization classification system. Together with staging, tumor classification is used to develop an appropriate treatment plan. While there are several diverse types of testicular tumors, 95% are classified as germ cell tumors, with the majority of testicular tumors in men ≤50 years of age classified as malignant germ cell tumors. An important concept regarding scrotal neoplasms is that until proven otherwise, a hard intratesticular mass should be regarded as cancerous. Therefore, a suspected tumor during workup is an indication for a radical transinguinal orchiectomy, providing tissue for the histological diagnosis in addition to a therapeutic treatment. Adjuvant post-orchiectomy therapies include retroperitoneal lymph node dissection, radiation therapy, and chemotherapy. Urologists treating testicular cancer patients should provide pre-treatment counseling on the potential impact on fertility along with the option of sperm banking. Various initiatives should be implemented to help minimize disparities and prevent diagnostic delays in testicular cancer. In particular, testicular self-examination may be used to help screen for testicular cancer and help increase the survival rate to give more years of life to patients

Scrotal imaging

Proper understanding of scrotal anatomy and pathological appearance on imaging in combination with familiarity of the patient’s history and exam findings is crucial for narrowing the differential diagnosis and providing accurate localization, diagnosis, cancer staging, and for follow-up. Ultrasound is the main imaging modality in the evaluation of scrotal conditions including acute scrotum, scrotal masses, and male infertility. Further imaging involves doppler assessment of vascularity and perfusion, computed tomography for tumor staging and follow-up after treatment, and magnetic resonance imaging which may be used as a diagnostic adjuvant to ultrasound in designated cases