225 research outputs found
Hierarchy of Chaotic Maps with an Invariant Measure
We give hierarchy of one-parameter family F(a,x) of maps of the interval
[0,1] with an invariant measure. Using the measure, we calculate
Kolmogorov-Sinai entropy, or equivalently Lyapunov characteristic exponent, of
these maps analytically, where the results thus obtained have been approved
with numerical simulation. In contrary to the usual one-parameter family of
maps such as logistic and tent maps, these maps do not possess period doubling
or period-n-tupling cascade bifurcation to chaos, but they have single fixed
point attractor at certain parameter values, where they bifurcate directly to
chaos without having period-n-tupling scenario exactly at these values of
parameter whose Lyapunov characteristic exponent begins to be positive.Comment: 18 pages (Latex), 7 figure
A new class of symbolic abstract neural nets
Starting from the way the inter-cellular communication takes place by means of protein channels and also from the standard knowledge about neuron functioning, we propose a computing model called a tissue P system, which processes symbols in a multiset rewriting sense, in a net of cells similar to a neural net. Each cell has a finite state memory, processes multisets of symbol-impulses, and can send impulses (?excitations?) to the neighboring cells. Such cell nets are shown to be rather powerful: they can simulate a Turing machine even when using a small number of cells, each of them having a small number of states. Moreover, in the case when each cell works in the maximal manner and it can excite all the cells to which it can send impulses, then one can easily solve the Hamiltonian Path Problem in linear time. A new characterization of the Parikh images of ET0L languages are also obtained in this framework
Crescimento, produção de fitomassa e teor de óleo essencial de folhas de capim citronela (Cymbopogon nardus (L.) Rendle) em cultivo consorciado com algodoeiro colorido no semiárido mineiro
Soil-landscape and climatic relationships in the middle Miocene of the Madrid Basin
The Miocene alluvial-lacustrine sequences of the Madrid Basin, Spain, formed in highly varied landscapes. The presence of various types of palaeosols allows assessment of the effects of local and external factors onsedimentation, pedogenesis and geomorphological development. In the northern, more arid, tectonicallyactive arca, soils were weakly developed in aggrading alluvial fans, dominated by mass flows. reflecting high sedimentation rates. In more distal parts of the fans and in playa lakes calcretes and dolocretes developed: the former were associated with Mg-poor fan sediments whitc: the latter formed on Mg-rich lake clays exposed during minar lake lowstands. The nonh-east part of the basin had a less arid climate. Alluvial fans in this area were dominated by stream Aood deposits, sourced by carbonate terrains. Floodplain and freshwater lakc deposits formed in distal areas. The high local supply of calcium carbonate may have contributed to the preferential developmenl on calcretes on the fans. Both the fan and floodplain palaeosols exhibit pedofacies relationships and more mature soils developed in settings more distant from the sediment sources. Palaeosols also developed on pond and lake margin carbonates, and led to the formation of palustrine limestones. The spatial distributions and stratigraphies of palaeosols in the Madrid Basin alluvial fans suggest that soil formation was controlled by local factors. These palaeosols differ from those seen in Quatemary fans. Which are characterized by climatically induced periods of stability and instability
Combining melphalan percutaneous hepatic perfusion with ipilimumab plus nivolumab in advanced uveal melanoma: first safety and efficacy data from the phase Ib part of the Chopin trial
Purpose To define a safe treatment dose of ipilimumab (IPI) and nivolumab (NIVO) when applied in combination with percutaneous hepatic perfusion with melphalan (M-PHP) in metastatic uveal melanoma (mUM) patients (NCT04283890), primary objective was defining a safe treatment dose of IPI/NIVO plus M-PHP. Toxicity was assessed according to Common Terminology Criteria for Adverse Events version 4.03 (CTCAEv4.03). Secondary objective was response rate, PFS and OS.Materials and Methods Patients between 18-75 years with confirmed measurable hepatic mUM according to RECIST 1.1 and WHO performance score 0-1 were included. Intravenous IPI was applied at 1 mg/kg while NIVO dose was increased from 1 mg/kg in cohort 1 to 3 mg/kg in cohort 2. Transarterial melphalan dose for M-PHP was 3 mg/kg (maximum of 220 mg) in both cohorts. Treatment duration was 12 weeks, consisting of four 3-weekly courses IPI/NIVO and two 6-weekly M-PHPs.Results Seven patients were included with a median age of 63.6 years (range 50-74). Both dose levels were well tolerated without dose-limiting toxicities or deaths. Grade III/IV adverse events (AE) were observed in 2/3 patients in cohort 1 and in 3/4 patients in cohort 2, including Systemic Inflammatory Response Syndrome (SIRS), febrile neutropenia and cholecystitis. Grade I/II immune-related AEs occurred in all patients, including myositis, hypothyroidism, hepatitis and dermatitis. There were no dose-limiting toxicities. The safe IPI/NIVO dose was defined as IPI 1 mg/kg and NIVO 3 mg/kg. There was 1 complete response, 5 partial responses and 1 stable disease (3 ongoing responses with a median FU of 29.1 months).Conclusion Combining M-PHP with IPI/NIVO was safe in this small cohort of patients with mUM at a dose of IPI 1 mg/kg and NIVO 3 mg/kg.Radiolog
Surface textural analysis of quartz sand grains from ODP Site 918 off the southeast coast of Greenland suggests glaciation of southern Greenland at 11 Ma
Management of early melanoma recurrence despite adjuvant anti-PD-1 antibody therapy
Background: Anti-programmed cell death protein 1 (PD-1) antibodies (PD1) prolong recurrence-free survival in high-risk resected melanoma; however, approximately 25%-30% of patients recur within 1 year. This study describes the pattern of recurrence, management and outcomes of patients who recur with adjuvant PD1 therapy.Patients and methods: Consecutive patients from 16 centres who recurred having received adjuvant PD1 therapy for resected stage III/IV melanoma were studied. Recurrence characteristics, management and outcomes were examined; patients with mucosal melanoma were analysed separately.Results: Melanoma recurrence occurred in 147 (17%) of ∼850 patients treated with adjuvant PD1. In those with cutaneous melanoma (n = 136), median time to recurrence was 4.6 months (range 0.3-35.7); 104 (76%) recurred during (ON) adjuvant PD1 after a median 3.2 months and 32 (24%) following (OFF) treatment cessation after a median 12.5 months, including in 21 (15%) who ceased early for toxicity. Fifty-nine (43%) recurred with locoregional disease only and 77 (57%) with distant disease. Of those who recurred locally, 22/59 (37%) subsequently recurred distantly. Eighty-nine (65%) patients received systemic therapy after recurrence. Of those who recurred ON adjuvant PD1, none (0/6) responded to PD1 alone; 8/33 assessable patients (24%) responded to ipilimumab (alone or in combination with PD1) and 18/23 (78%) responded to BRAF/MEK inhibitors. Of those who recurred OFF adjuvant PD1, two out of five (40%) responded to PD1 monotherapy, two out of five (40%) responded to ipilimumab-based therapy and 9/10 (90%) responded to BRAF/MEK inhibitors.Conclusions: Most patients who recur early despite adjuvant PD1 develop distant metastases. In those who recur ON adjuvant PD1, there is minimal activity of further PD1 monotherapy, but ipilimumab (alone or in combination with PD1) and BRAF/MEK inhibitors have clinical utility. Retreatment with PD1 may have activity in select patients who recur OFF PD1.</p
Self-help groups challenge health care systems in the US and UK
Purpose: This research considers how self-help groups (SHGs) and self- help organizations (SHOs) contribute to consumerist trends in two different societies: United States and United Kingdom. How do the health care systems and the voluntary sectors affect the kinds of social changes that SHGs/SHOs make?
Methodology/approach: A review of research on the role of SHGs/SHOs in contributing to national health social movements in the UK and US was made. Case studies of the UK and the US compare the characteristics of their health care systems and their voluntary sector. Research reviews of two community level self-help groups in each country describe the kinds of social changes they made.
Findings: The research review verified that SHGs/SHOs contribute to national level health social movements for patient consumerism. The case studies showed that community level SHGs/SHOs successfully made the same social changes but on a smaller scale as the national movements, and the health care system affects the kinds of community changes made.
Research limitations: A limited number of SHGs/SHOs within only two societies were studied. Additional SHGs/SHOs within a variety of societies need to be studied.
Originality/value of chapter
Community SHGs/SHOs are often trivialized by social scientists as just inward-oriented support groups, but this chapter shows that local groups contribute to patient consumerism and social changes but in ways that depend on the kind of health care system and societal context
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