Observation of a linear temperature dependence of the critical current density in a Ba_{0.63}K_{0.37}BiO_3 single crystal

For a Ba_{0.63}K_{0.37}BiO_3 single crystal with T_c=31 K, H_{c1}=750 Oe at 5 K, and dimensions 3x3x1 mm^3, the temperature and field dependences of magnetic hysteresis loops have been measured within 5-25 K in magnetic fields up to 6 Tesla. The critical current density is J_c(0)=1.5 x 10^5 A/cm^2 at zero field and 1 x 10^5 A/cm^2 at 1 kOe at 5 K. J_c decreases exponentially with increasing field up to 10 kOe. A linear temperature dependence of J_c is observed below 25 K, which differs from the exponential and the power-law temperature dependences in high-Tc superconductors including the BKBO. The linear temperature dependence can be regarded as an intrinsic effect in superconductors.Comment: RevTex, Physica C Vol. 341-348, 729 (2000

Research Based Strategies in Reading and Writing for Content Area Teachers: A Website to Support Growth in Academic Language

The population of English language learners in general education classrooms is growing every year and teachers are finding that they need strategies to support these learners in reading and writing along with helping them adapt to school in another culture. Without classroom support, it becomes more difficult for these students to acquire the academic language needed to be successful and the opportunity gap continues to widen. This website designed for this project focuses on research based reading and writing strategies for content area teachers at the secondary level, specifically grades six through 12. Strategies for skills such as comprehension, vocabulary development, summarizing, and writing are featured on this website. This project also involved creating additional resources for teachers to include information about language levels, challenges English learners at different levels face, and what English learners can do at different levels of language development when given classroom assignments. The goal of this project is to give content area teachers a place to go for information and strategies so they can support the English learners that are placed in their classes

Essays on Asymmetric Information

Thesis (Ph.D.) - Indiana University, Business, 2014My dissertation analyzes the credible communication of seller information to buyers. My first essay, "New and Improved?", considers firms' incentives to introduce new product versions and the corresponding beliefs of consumers about such products' quality when they have no direct information about the product other than it is new. I find that consumers rationally deduce new product versions are on average better and so pay a pricing premium, in turn leading some firms to exploit the new product signal by selling new versions that are only trivially different from their older version or that require inefficiently high upgrade costs. Notwithstanding this, I show that some "new product signaling" can increase welfare by counteracting Arrow's underinvestment problem. The second essay, "Physician Overtreatment and Undertreatment with Partial Delegation", considers strategic communication from doctors selling medical services to patients. We find that communication problems stemming from misaligned incentives lead the patient to being overtreated for some health states and undertreated in others. Stronger financial incentives for doctors lead to more exaggeration and hence more skepticism, thereby leading to even more exaggeration as the doctor tries to persuade the patient to accept treatment. Insurance makes patients worry less about paying for overtreatment, thereby reducing the need for doctors to exaggerate, and making each side better off by reducing miscommunication. We also resolve an open question in the partial delegation literature by showing that the equilibrium we examine is the most informative equilibrium

Behavior of turbulent boundary layers on curved convex walls

The system of linear differential equations which indicated the approach of separation and the so-called "boundary-layer thickness" by Gruschwitz is extended in this report to include the case where the friction layer is subject to centrifugal forces. Evaluation of the data yields a strong functional dependence of the momentum change and wall drag on the boundary-layer thickness radius of curvature ratio for the wall. It is further shown that the transition from laminar to turbulent flow occurs at somewhat higher Reynolds Numbers at the convex wall than at the flat plate, due to the stabilizing effect of the centrifugal forces

The surgical point of view of the geriatric patient — Urinary incontinence

Summary: Background: Urinary incontinence is one of the most frequent diseases in the ageing population. The aim of this manuscript is to present the current knowledge on urinary incontinence regarding (i) prevalence, (ii) pathogenesis, (iii) types, (iv) diagnostic assessment, and (v) treatment options. Methods: The current literature regarding urinary incontinence with special reference to the geriatric patient was reviewed. Results: According to a study performed recently in the Vienna area, 36.0% of women and 11.5% of men aged 70 years or older report urinary incontinence. Several factors, such as urodynamic changes, structural alterations of the lower urinary tract, increased sensory input, and impaired central control of the micturition reflex, contribute to the high prevalence of urinary incontinence with age. The four most common forms of urinary incontinence in the geriatric patient are combined stress/urge incontinence, pure urge incontinence, pure stress incontinence, and overflow incontinence. Diagnostic steps are classified into "mandatory”, "recommended”, and "indicated in selected cases only”. Particularly the "mandatory tests” are simple to perform and need no special equipment. Therapeutic options should be directed to the type of urinary incontinence as well as the physical and mental status of the patient. Conclusions: Urinary incontinence is highly prevalent with age. Conservative treatment is the therapy of choice for urge incontinence and mild to moderate forms of stress and overflow incontinence in the geriatric patien

Differentiated Thyroid Cancer—Treatment: State of the Art

Differentiated thyroid cancer (DTC) is a rare malignant disease, although its incidence has increased over the last few decades. It derives from follicular thyroid cells. Generally speaking, the prognosis is excellent. If treatment according to the current guidelines is given, cases of recurrence or persistence are rare. DTC requires special expertise by the treating physician. In recent years, new therapeutic options for these patients have become available. For this article we performed a systematic literature review with special focus on the guidelines of the American Thyroid Association, the European Association of Nuclear Medicine, and the German Society of Nuclear Medicine. For DTC, surgery and radioiodine therapy followed by levothyroxine substitution remain the established therapeutic procedures. Even metastasized tumors can be cured this way. However, in rare cases of radioiodine-refractory tumors, additional options are to be discussed. These include strict suppression of thyroid-stimulating hormone (also known as thyrotropin, TSH) and external local radiotherapy. Systemic cytostatic chemotherapy does not play a significant role. Recently, multikinase or tyrosine kinase inhibitors have been approved for the treatment of radioiodine-refractory DTC. Although a benefit for overall survival has not been shown yet, these new drugs can slow down tumor progression. However, they are frequently associated with severe side effects and should be reserved for patients with threatening symptoms only

DYST (Did You See That?): An Amplified Covert Channel That Points To Previously Seen Data

Covert channels are unforeseen and stealthy communication channels that enable manifold adversary scenarios. However, they can also allow the exchange of confidential information by journalists. All covert channels described until now therefore need to craft seemingly legitimate information flows for their information exchange, mimicking unsuspicious behavior. In this paper, we present DYST, which represents a new class of covert channels we call history covert channels jointly with the new paradigm of covert channel amplification. History covert channels can communicate almost exclusively by pointing to unaltered legitimate traffic created by regular network nodes. Only a negligible fraction of the covert communication process requires the transfer of actual covert channel information by the covert channel's sender. This allows, for the first time, an amplification of the covert channel's message size, i.e., minimizing the fraction of actually transferred secret data by a covert channel's sender in relation to the overall secret data being exchanged. We extend the current taxonomy for covert channels to show how history channels can be categorized. We describe multiple scenarios in which history covert channels can be realized, theoretically analyze the characteristics of these channels and show how their configuration can be optimized for different implementations. We further evaluate the robustness and detectability of history covert channels.Comment: 18 pages, rev