Complex Dynamics and Multistability in a Damped Harmonic Oscillator with Delayed Negative Feedback

A center manifold reduction and numerical calculations are used to demonstrate the presence of limit cycles, two-tori, and multistability in the damped harmonic oscillator with delayed negative feedback. This model is the prototype of a mechanical system operating with delayed feedback. Complex dynamics are thus seen to arise in very plausible and commonly occurring mechanical and neuromechanical feedback systems

Discomfort experienced at the daily life of relatives of people admitted at ICU

This is a qualitative research that aimed to get to know the discomforts experienced at the daily life of relatives of people admitted at the intensive care unit (ICU). It happened on a general ICU at a public hospital, in Salvador-BA, by the second half of 2009. Nine relatives of people admitted were interviewed. The technique used was the analysis from the Grounded Theory. The results showed that the interaction of the families with the reality of life threat from the relative admitted, had as main discomfort, the discontinuity in their daily life, which was characterized by four categories: Living the distress of a possible loss, difficulties to take care of themselves, facing a separation in the family, suffering with changes in their social and professional lives. These discomforts can be minimized by the healthcare team’s effectiveness to the demands of the family and the support of its social network

Genotyping of circulating tumor DNA in cholangiocarcinoma reveals diagnostic and prognostic information

Diagnosis of Cholangiocarcinoma (CCA) is difficult, thus a noninvasive approach towards (i) assessing and (ii) monitoring the tumor-specific mutational profile is desirable to improve diagnosis and tailor treatment. Tumor tissue and corresponding ctDNA samples were collected from patients with CCA prior to and during chemotherapy and were subjected to deep sequencing of 15 genes frequently mutated in CCA. A set of ctDNA samples was also submitted for 710 gene oncopanel sequencing to identify progression signatures. The blood/tissue concordance was 74% overall and 92% for intrahepatic tumors only. Variant allele frequency (VAF) in ctDNA correlated with tumor load and in the group of intrahepatic CCA with PFS. 63% of therapy naive patients had their mutational profile changed during chemotherapy. A set of 76 potential progression driver genes was identified among 710 candidates. The molecular landscape of CCA is accessible via ctDNA. This could be helpful to facilitate diagnosis and personalize and adapt therapeutic strategies

World Health Organization Discontinues Its Drinking-Water Guideline for Manganese

Background: The World Health Organization (WHO) released the fourth edition of Guidelines for Drinking-Water Quality in July 2011. In this edition, the 400-µg/L drinking-water guideline for manganese (Mn) was discontinued with the assertion that because “this health-based value is well above concentrations of manganese normally found in drinking water, it is not considered necessary to derive a formal guideline value.

Oregon's forestry outlook: an uncertain future

The theme for the 1989 Starker Lectures concerned uncertainty surrounding forests and forestry in Oregon and the Pacific Northwest. It was a timely theme. Indeed, the uncertainties concerning trade-offs among commodity production and environment and the allocation of forest land, especially public lands, loom large as we enter the decade of the 90's. We invited for the 1989 lectures speakers who would address current issues not in the value-laden terms of the day, but in a more detached and analytical way, an approach that better permits the listener or reader to make judgements based on factual and scientific information. This, we believe, is a proper role for the College of Forestry