49 research outputs found
ANALYTICAL AND COMPUTER-SIMULATION TECHNIQUES FOR A STOCHASTIC-MODEL ARISING IN DISCOUNTING CONTINUOUS UNIFORM CASH FLOWS
Present-value models axe currently available for both single cash flows
and continuous uniform cash flows under uncertain timing. Recent work by
the authors has concentrated mainly on establishing theoretical results
concerning the conditions under which unimodality will be introduced
into the present-value distribution, particularly under exponential
timing. Apart from the conventional (0) unimodality, there are two other
forms of unimodality available which refer more to the nature of the
unimodal behaviour rather than its location.
When the timing mechanism operating for a continuous uniform cash flow
is modelled by a geometrically distributed sum of exponential
inter-assessment times, this paper establishes that the present-value
distribution adopts a form of unimodality which is conceptually and
structurally distinct from that form of unimodality adopted within the
single cash flow analogue. Each present-value distribution will
therefore become (0) unimodal under different prevailing economic
conditions. One financial implication of these results is that it should
be possible to develop coherent funding strategies for selecting a
single cash flow option or a continuous uniform cash flow option having
due regard to the current financial climate
Revista de educación
Resumen tomado de la publicación. Monográfico con el título: 'La educación ante la inclusión del alumnado con necesidades específicas de apoyo'Se examinan los puntos de vista de los maestros de educación general griega respecto a la viabilidad y conveniencia de adaptaciones en la enseñanza rutinaria así como explorar el razonamiento subyacente en sus respuestas. Los datos se recogen mediante entrevistas que incluyen preguntas estructuradas y otras semiestructuradas. Al procesar las entrevistas se utiliza una versión modificada de la Escala de Adaptación de la Enseñanza (EAE). La escala permite la evaluación de las percepciones de los maestros con respecto a las adaptaciones en la enseñanza y su viabilidad y conveniencia en cinco de las seis categorías originales que incluyen: organización en el aula, estrategias de agrupamiento, enseñanza adicional, ajuste de actividades y análisis de la formación. La mayoría de los participantes comunicaron que utilizan la mayoría de las adaptaciones pero que, nunca o raramente, han utilizado: agrupamiento entre clases, actividades con varios grados de dificultad, actividades diversas, recursos específicos y ordenadores. Éstas son también las adaptaciones más deseadas que viables, a excepción de la utilización de materiales específicos. Al mismo tiempo, una minoría de maestros no quería algunas adaptaciones, entre las que están: agrupar clases, agrupar a los estudiantes en parejas, proporcionar enseñanza adicional a algunos subgrupos de la clase, implementar actividades con varios niveles de dificultad, mandar diversas actividades, y utilizar material alternativo, recursos específicos y ordenadores. El principal resultado de la investigación es que todos los participantes se aferran al ritmo de trabajo, temario e implementación del libro de texto. Los inconvenientes observados son la falta de tiempo, temario sobrecargado, área académica influida por la manera en la que los maestros respondieron, errores conceptuales de los maestros en la comprensión y conocimiento de adaptaciones particulares. Se analizan las implicaciones en la formación de maestros, a la vez que se habla de respuestas de inclusión y prácticas reglamentarias.The aim of the study is to examine greek mainstream teachers' views concerning the feasibility and desirability of routine instructional asaptations, and to explore the reasoning underpinning their responses. Data were collected by using interviews, which included both highly-and semi-structured questions. A modified version of the Teaching Adaptation Scale (TAS) was used for the interviews process. The scale allowed for the evaluation of teachers' perceptions of instructional adaptations and their feasibility and desirability in five out of the six original categories, including: classroom management, grouping strategies, additional teaching, activity adjustment and foprmative assessment. The majority of participants reported that they use frequently most of the adaptations included whilst those used rarely or never used by teachers were: between-class grouping, activities at various levels of difficulty, diverse activities, specific resources and computers. These were also the adaptations -with the exception of using specific resources- that were deemed to be more desirable than feasible. At the same time, some adaptations were not desired by a minority of teachers including between-class grouping, grouping all students in pairs, providing additional teaching to certain subgroups in the class, implementing activities at variuos levels of difficulty, asking for diverse activities, and using alternative material, specific resources and computers. The most salient and recurrent finding was that all of the participants were strngly bounded by pace, curriculum and the implementation of the textbook. Lack of time and time and the overloaded sykkabuses were reported as some of the main barriers prohibiting the implementation of adaptations. Further, the academic context seemed to influence the pattern of teachers' responses while a number of misconceptions were revealed in teachers' understanding and knowledge of particular adaptations. Implications in terms of teachers' trining, inclusive responses and policy practices are discussed and analysed.MadridBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]
A stochastic model for proactive risk management decisions
The analysis of stochastic discounting models provides one of the more
powerful tools available for decision-making under conditions of
uncertainty. This paper is mainly devoted to the establishment of
properties and applications of a particular stochastic discounting
model. More precisely, the paper investigates some of the theoretical
problems encountered in a stochastic discounting model when assessing
mutually exclusive options, and establishes the advantages of
considering risk retention in proactive risk-management programs
Staphylococcus aureus carriage status in patients with hidradenitis suppurativa: An observational cohort study in a tertiary referral hospital in Athens, Greece
Background: Hidradenitis suppurativa (HS) is a chronic, recurrent, auto-inflammatory disease that affects the pilosebaceous unit in apocrine gland-bearing areas. Bacteria are thought to play a role in the development and progression of disease. In addition, antibiotics are frequently used as first-line management for HS. We sought to determine the carriage status of Staphylococcus aureus and its resistance to antibiotics among patients with HS in a tertiary referral hospital in Athens, Greece. Methods: In this observational cohort study, 68 consecutive patients attending the HS clinic of "Attikon" General University Hospital in Athens, Greece, during a 9-month period were enrolled. All patients had not received any antibiotic therapy for any reason during the previous 3 months before enrollment. Nasal and oropharyngeal samplingwere obtained, and specimens were tested for the presence of S. aureus.Antibiotic susceptibility testing was performed using the VITEK 2 system. Standard statistical tests, descriptive statistics tests, and χ2 and Pearson correlation tests were performed, using IBM SPSS Statistics 25.The level of significance was set at a pvalue <0.05. Results: Sixty-eight patients with HS were studied. There were 44 females (64.7%) and 24 males (35.3%). The mean age was 36.63 ± 13.0 (IQR = 21), and the mean age at onset of disease was 23.90 ± 11.53 (IQR = 14). The mean duration of disease was 12.74 ± 10.20 years (IQR = 15). Fifteen (22.1%) of the patients were Hurley stage I, 22 (32.4%) were Hurley stage II, and 31 (45.6%) were Hurley stage III. S. aureus carriage was detected in 17 patients (25%). Six of them (35.3%) had MRSA strains. There was an increased prevalence of S. aureus colonization (p = 0.058) and MRSA (p = 0.101) in Hurley stage III patients, but this result was not statistically significant. Conclusions: We found a 25% prevalence of S. aureus colonization (17/68 patients) and a 35.3% prevalence of MRSA (6/17) among our HS patients. There was an increased prevalence of S. aureusand MRSA positivity in HS patients with Hurley stage III. Further studies are needed to clarify the possible clinical significance of S. aureus carriage in the disease development and progression as well as in the treatment outcome. © 2019 S. Karger AG, Basel
Variability in cirrus cloud properties using a PollyXT Raman lidar over high and tropical latitudes
Measurements of geometrical and optical properties of cirrus clouds, performed with a multi-wavelength PollyXT Raman lidar during the period 2008 to 2016, are analysed. The measurements were performed with the same instrument, during sequential periods, in three places at different latitudes, Gwal Pahari (28.43-N, 77.15-E; 243ma.s.l.) in India, Elandsfontein (26.25-S, 29.43-E; 1745ma.s.l.) in South Africa and Kuopio (62.74-N, 27.54-E; 190ma.s.l.) in Finland. The lidar dataset was processed by an automatic cirrus cloud masking algorithm, developed in the frame of this work. In the following, we present a statistical analysis of the lidar-retrieved geometrical characteristics (cloud boundaries, geometrical thickness) and optical properties of cirrus clouds (cloud optical depth, lidar ratio, ice crystal depolarisation ratio) measured over the three areas that correspond to subtropical and subarctic regions as well as their seasonal variability. The effect of multiple scattering from ice particles to the derived optical products is also considered and corrected in this study. Our results show that cirrus layers, which have a noticeable monthly variability, were observed between 6.5 and 13 km, with temperatures ranging from ° 72 to ° 27-C. The observed differences on cirrus clouds geometrical and optical properties over the three regions are discussed in terms of latitudinal and temperature dependence. The latitudinal dependence of the geometrical properties is consistent with satellite observations, following the pattern observed with CloudSat, with decreasing values towards the poles. The geometrical boundaries have their highest values in the subtropical regions, and overall, our results seem to demonstrate that subarctic cirrus clouds are colder, lower and optically thinner than subtropical cirrus clouds. The dependence of cirrus cloud geometrical thickness and optical properties on mid-cirrus temperatures shows a quite similar tendency for the three sites but less variability for the subarctic dataset. Cirrus clouds are geometrically and optically thicker at temperatures between ° 45 and ° 35-C, and a second peak is observed at lower temperatures-° 70-C for the subarctic site. Lidar ratio values also exhibit a pattern, showing higher values moving toward the poles, with higher mean values observed over the subarctic site. The dependency of the mid-cirrus temperatures on the lidar ratio values and the particle depolarisation values is further examined. Our study shows that the highest values of the cirrus lidar ratio correspond to higher values of cirrus depolarisation and warmer cirrus. The kind of information presented here can be rather useful in the cirrus parameterisations required as input to radiative transfer models and can be a complementary tool for satellite products that cannot provide cloud vertical structure. In addition, ground-based statistics of the cirrus properties could be useful in the validation and improvement of the corresponding derived products from satellite retrievals. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License
Lymphoprolipherative skin reactions induced by anti-TNFα: an open question
Although anti-TNFα agents have revolutionized the treatment of many inflammatory diseases, various concerns have been reported regarding the risks of cancer development, as well as acceleration of the progression of subclinical, preexisting malignancies. In this case series, we investigated the provocative effect of anti-TNFα drugs in the development of cutaneous mycosis fungoides (MF)-like lymphoproliferative reactions. We describe five patients aged between 25–63 diagnosed with autoimmune disorders (psoriatic arthritis–one patient, Crohn’s disease–one patient and ankylosing spondylitis–three patients) who received anti-TNFα agents before the development of a cutaneous lymphoproliferative reaction. Histological and immunophenotypical analysis was typical for mycosis fungoides in all of them. Anti-TNFα agents were stopped with regression of the skin rash. A direct effect of anti-TNFα agents in the development of lymphoproliferative reactions (including MF) is suggested and further analyzed. Treatment cessation can be therapeutic. © 2019, © 2019 Taylor & Francis Group, LLC
Another window into tumor microenvironment: a case of Β-cell rich folliculotropic mycosis fungoides responding to rituximab
The role of tumor infiltrating immune cells in cancer development and progression is a new, promising field in oncological research. An increasing number of novel anti-cancer agents are focussing on the tumor microenvironment. Various studies have reported on B-cell infiltrates in mycosis fungoides (MF), but despite the substantial volume of interesting findings, solid evidence regarding their specific role in cancer is still vague. We present a case of tumor stage MF responding to rituximab. We support the hypothesis that lymphoma-infltrating B-cells have a significant impact on cutaneous lymphoma course and seem to be both an important and effective therapeutic target. The reduction of B-cell population led to disease’s overall remission, probably by restoring patient’s immunologic tumor control. © 2020 Australasian College of Dermatologist