885 research outputs found
Spatial interactions in agent-based modeling
Agent Based Modeling (ABM) has become a widespread approach to model complex
interactions. In this chapter after briefly summarizing some features of ABM
the different approaches in modeling spatial interactions are discussed.
It is stressed that agents can interact either indirectly through a shared
environment and/or directly with each other. In such an approach, higher-order
variables such as commodity prices, population dynamics or even institutions,
are not exogenously specified but instead are seen as the results of
interactions. It is highlighted in the chapter that the understanding of
patterns emerging from such spatial interaction between agents is a key problem
as much as their description through analytical or simulation means.
The chapter reviews different approaches for modeling agents' behavior,
taking into account either explicit spatial (lattice based) structures or
networks. Some emphasis is placed on recent ABM as applied to the description
of the dynamics of the geographical distribution of economic activities, - out
of equilibrium. The Eurace@Unibi Model, an agent-based macroeconomic model with
spatial structure, is used to illustrate the potential of such an approach for
spatial policy analysis.Comment: 26 pages, 5 figures, 105 references; a chapter prepared for the book
"Complexity and Geographical Economics - Topics and Tools", P. Commendatore,
S.S. Kayam and I. Kubin, Eds. (Springer, in press, 2014
Improvement of heart rate recovery after exercise training in older people.
Twenty-four subjects aged 70 and older were retrospectively selected from our archives and screened for symptoms of cardiovascular disease. Baseline exercise test was negative for myocardial ischemia in all subjects. All subjects had completed an 8-week program, performed for
a variety of indications and consisting of an aerobic physical training program including 30 minutes of cycling three times per week at 65% to 75% of maximum heart rate achieved at peak exercise test performed at enrollment, an educational intervention, dietary advice, and psychological
support. All subjects underwent a cardiopulmonary exercise test (CPX) before and at the end of
exercise training. At the end of each CPX, peak oxygen uptake (VO2peak), the rate of increase of ventilation per unit of increase of carbon dioxide production (VE/VCO2slope), and HRR were recorded. Twenty-five healthy subjects younger than 60 with no evidence of exercise-induced myocardial ischemia and not enrolled in any exercise training program were also retrospectively
selected from our archives and used as a control group for analyzing HRR. These patients performed two exercise tests several weeks apart. Several studies have shown that changes in vagal tone can be used as an outcome tool that helps identify patients or subjects with or without cardiovascular disease at risk for a cardiovascular event, although the evidence of a prognostic value of HRR in older subjects without cardiovascular disease is rather poor. In this study, exercise training resulted in HRR improvement in healthy elderly subjects, suggesting that exercise training improves vagal/sympathetic balance in older subjects without cardiovascular disease as well. Whether the observed improvement in HRR may have long-term beneficial prognostic effects was not the aim of the study, although a beneficial effect might be postulated, in light of the Framingham dat
Longitudinal and latitudinal variations of the total ozone over the Central Andes
From the Total Ozone Mapping Spectrometer (TOMS) data released by NASA, some analyses had been done in order to point out anomalies in the time and space distributions of the total ozone. Also some explanations for them have been
tried. Here we focus on the longitudinal and altitudinal anomalies in a region characterised by strong variations in orography, as are the Andes at low and mid latitude. As a result of the analysis, we conclude that there is a depletion of the total ozone over the Altiplano and discuss some possible explanations of the phenomenon
Design and Field Measurements of a Linear Accelerator Endowed with Single Feed with Movable Short Coupler
Field asymmetries in the rf coupler of accelerating structures degrade the projected beam transverse emittance, especially at low energy. This paper presents an alternative single feed coupler design that reduces the dipolar
and the quadrupolar field components by exploiting a movable short circuit placed on the opposite waveguide. The structure has been simulated and optimized with the Ansys HFSS simulation code. RF measurements on an aluminum prototype machined in the "Elettra - Sincrotrone Trieste S.C.p.A.", are here presented. Such results are in good agreement with the simulations
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Antibiotics for exacerbations of asthma.
BACKGROUND: Asthma is a chronic respiratory condition that affects over 300 million adults and children worldwide. It is characterised by wheeze, cough, chest tightness, and shortness of breath. Symptoms typically are intermittent and may worsen over a short time, leading to an exacerbation. Asthma exacerbations can be serious, leading to hospitalisation or even death in rare cases. Exacerbations may be treated by increasing an individual's usual medication and providing additional medication, such as oral steroids. Although antibiotics are sometimes included in the treatment regimen, bacterial infections are thought to be responsible for only a minority of exacerbations, and current guidance states that antibiotics should be reserved for cases in which clear signs, symptoms, or laboratory test results are suggestive of bacterial infection. OBJECTIVES: To determine the efficacy and safety of antibiotics in the treatment of asthma exacerbations. SEARCH METHODS: We searched the Cochrane Airways Trials Register, which contains records compiled from multiple electronic and handsearched resources. We also searched trial registries and reference lists of primary studies. We conducted the most recent search in October 2017. SELECTION CRITERIA: We included studies comparing antibiotic therapy for asthma exacerbations in adults or children versus placebo or usual care not involving an antibiotic. We allowed studies including any type of antibiotic, any dose, and any duration, providing the aim was to treat the exacerbation. We included parallel studies of any duration conducted in any setting and planned to include cluster trials. We excluded cross-over trials. We included studies reported as full-text articles, those published as abstracts only, and unpublished data. DATA COLLECTION AND ANALYSIS: At least two review authors screened the search results for eligible studies. We extracted outcome data, assessed risk of bias in duplicate, and resolved discrepancies by involving another review author. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs), and continuous data as mean differences (MDs), all with a fixed-effect model. We described skewed data narratively. We graded the results and presented evidence in 'Summary of findings' tables for each comparison. Primary outcomes were intensive care unit/high dependence unit (ICU/HDU) admission, duration of symptoms/exacerbations, and all adverse events. Seconday outcomes were mortality, length of hospital admission, relapse after index presentation, and peak expiratory flow rate (PEFR). MAIN RESULTS: Six studies met our inclusion criteria and included a total of 681 adults and children with exacerbations of asthma. Mean age in the three studies in adults ranged from 36.2 to 41.2 years. The three studies in children applied varied inclusion criteria, ranging from one to 18 years of age. Five studies explicitly excluded participants with obvious signs and symptoms of bacterial infection (i.e. those clearly meeting current guidance to receive antibiotics). Four studies investigated macrolide antibiotics, and two studies investigated penicillin (amoxicillin and ampicillin) antibiotics; both studies using penicillin were conducted over 35 years ago. Five studies compared antibiotics versus placebo, and one was open-label. Study follow-up ranged from one to twelve weeks. Trials were of varied methodological quality, and we were able to perform only limited meta-analysis.None of the included trials reported ICU/HDU admission, although one participant in the placebo group of a study including children with status asthmaticus experienced a respiratory arrest and was ventilated. Four studies reported asthma symptoms, but we were able to combine results for only two macrolide studies of 416 participants; the MD in diary card symptom score was -0.34 (95% confidence interval (CI) -0.60 to -0.08), with lower scores (on a 7 point scale) denoting improved symptoms. Two macrolide studies reported symptom-free days. One study of 255 adults authors reported the percentage of symptom-free days at 10 days as 16% in the antibiotic group and 8% in the placebo group. In a further study of 40 children study authors reported significantly more symptom-free days at all time points in the antibiotic group compared with the usual care group. The same study reported the duration in days of the index asthma exacerbation, again favouring the antibiotic group. One study of a penicillin including 69 participants reported asthma symptoms at hospital discharge; the between-group difference for both studies was reported as non-significant.We combined data for serious adverse events from three studies involving 502 participants, but events were rare; the three trials reported only 10 events: five in the antibiotic group and five in the placebo group. We combined data for all adverse events (AEs) from three studies, but the effect estimate is imprecise (OR 0.99, 95% CI 0.69 to 1.43). No deaths were reported in any of the included studies.Two studies investigating penicillins reported admission duration; neither study reported a between-group difference. In one study (263 participants) of macrolides, two participants in each arm were reported as experiencing a relapse, defined as a further exacerbation, by the six-week time points. We combined PEFR endpoint results at 10 days for two macrolide studies; the result favoured antibiotics over placebo (MD 23.42 L/min, 95% CI 5.23 to 41.60). One study in children reported the maximum peak flow recorded during the follow-up period, favouring the clarithromycin group, but the confidence interval includes no difference (MD 38.80, 95% CI -11.19 to 88.79).Grading of outcomes ranged from moderate to very low quality, with quality of outcomes downgraded for suspicion of publication bias, indirectness, imprecision, and poor methodological quality of studies. AUTHORS' CONCLUSIONS: We found limited evidence that antibiotics given at the time of an asthma exacerbation may improve symptoms and PEFR at follow-up compared with standard care or placebo. However, findings were inconsistent across the six heterogeneous studies included, two of the studies were conducted over 30 years ago and most of the participants included in this review were recruited from emergency departments, limiting the applicability of findings to this population. Therefore we have limited confidence in the results. We found insufficient evidence about several patient-important outcomes (e.g. hospital admission) to form conclusions. We were unable to rule out a difference between groups in terms of all adverse events, but serious adverse events were rare
A First Phylogenetic Assessment of \u3ci\u3eDictyonemo\u3c/i\u3e s.lat in Southwestern North America Reveals Three New Basidiolichens, Described in Honor James D. Lawrey
Three species of lichenized basidiomycetes in the Dictyonema clade from southeastern North America are described as new to science: Cyphellostereum georgianum, C. jamesianum and Dictyonema lawreyi, all with a crustose-filamentous growth form. Based on ITS sequences, the species form well-supported monophyletic clades in a phylogeny and are represented by at least two specimens each. They are also distinguishable by morphological and anatomical characters. These new findings emphasize the importance of lichenological studies in North America, especially in historically understudied taxonomic groups, such as basidiolichens. This study is dedicated to James D. Lawrey on the occasion of his 70th birthda
Vulnerable personality and Takotsubo cardiomyopathy consequent to emotional stressful events: a clinical case report
Introduction: Although the onset of Takotsubo cardiomyopathy (TTC) can be triggered by an acute, intense emotional stress, the exact pathogenic mechanisms still remain undefined. Presentation: A 58-year-old female was sent by ambulance to the Emergency Department (ED) for chest pain and ST elevations on ECG. Her chest pain began 3 hours before on admission after a domestic argument. Transthoracic echocardiogram showed severe systolic dysfunction with an ejection fraction of 20%. Cardiac catheterization revealed no significant coronary artery disease. The left ventriculogram showed apical ballooning with hyperdynamic proximal segments. A diagnosis of Takotsubo Cardiomyophaty (TTC) was made according to the Mayo Clinic 2008 criteria. The patient evolved with improvement of her condition and, therefore, was discharged from the hospital. Follow-up echocardiogram seven days later showed normal LV size and function with ejection fraction (EF) of 43%. Paykel Life Stress Event Scale identified as emotional trigger a domestic argument occurred 3 hours before symptom onset. History showed a major life stress event, death of a loved one, six months before symptoms. The patient underwent psychological assessment after hospital discharge by Emotional Regulation Questionnaire and BDI showing high suppression/ low reappraisal profile and moderate depression. Conclusion: This case highlights the hypothesis of a possible link between cognitive emotional processing and vulnerability to Takotsubo syndrome
One-Step Laparoscopic Management of a Female Adnexal Tumor of Wolffian Origin
We report a case of female adnexal tumor of Wolffian origin (FATWO), a rare neoplasm arising from the mesonephric ducts. A 48-year-old woman came first to our center for a recent discovery of a pelvic mass. Transvaginal ultrasonographic findings suggested a solid right para-ovarian mass suspected to be malignant. After thorough counseling, the patient underwent operative laparoscopy for excision of the para-ovarian mass with frozen section (FS) examination resulting in the diagnosis of a poorly differentiated adenocarcinoma. In this case, FS results allowed performing a comprehensive oncological staging, through a totally laparoscopic extrafascial hysterectomy, bilateral adnexectomy, total omentectomy, pelvic wall peritonectomy, and pelvic, parasacral and para-aortic lymphadenectomy. Final pathological and immunohistochemical results confirmed the diagnosis of FATWO. To our knowledge, this is the first case of FATWO managed entirely by a minimally invasive laparoscopic approach in a single surgical session
Endometriosis in the time of internet: how web navigation affects women with endometriosis
Objectives: Patients often search for health-related information on the internet allthough this trend may have some benefits, it also has some risks, such as misinformation. The aim of this study is to evaluate how Internet information seeking affect the level of anxiety in patients with endometriosis. Materials and methods: This prospective observational study was conducted at our outpatient clinic between March 2019 and December 2020. We enrolled We enrolled all patients with a confirmed sonographic diagnosis of endometriosis who had sought information about the disease prior to our visit. We divided them into two groups based on the source of information (Internet only vs multiple sources). Before the visit, we asked women to fill-in validated questionnaires about anxiety, such as the Generalized Anxiety Disorder-7 (GAD) and the Spielberg State Trait Anxiety Inventory (STAI- Y6) and the Endometriosis Health Profile (EHP) − 5. After the visit, the STAI-Y6 was resubmitted to each woman. Results: We enrolled 200 women who filled-in the questionnaires: 46 reported the Internet as the only source of information, 52 sought information also from medically qualified sources, 74 consulted only healthcare professionals, and 28 resorted to medical journals. Women who used the Internet as their exclusive source of information were younger on average and their STAI-Y6 score after the visit was significantly lower compared to other group (34.1 ± 11.5 vs 42.1 ± 14.7, p =.001). Moreover, the difference between the STAI-Y6 scores before and after our assessment was higher in these women (-18.3 ± 14.7 vs −10.3 ± 16.5, p =.003). Conclusions: Women who sought information online were younger, had lower levels of state trait anxiety after our medical evaluation, and a had a greater reduction in anxiety levels after our examination compared to women who consulted other sources to learn more about endometriosis.KEY MESSAGES Women using only Internet are younger than those who use other sources of information. Women who researched symptoms online showed higher pre-examination anxiety levels. Patients with severe pain symptoms consulted both the internet and professionals
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