Parabolic resonances and instabilities in near-integrable two degrees of freedom Hamiltonian flows

When an integrable two-degrees-of-freedom Hamiltonian system possessing a circle of parabolic fixed points is perturbed, a parabolic resonance occurs. It is proved that its occurrence is generic for one parameter families (co-dimension one phenomenon) of near-integrable, t.d.o. systems. Numerical experiments indicate that the motion near a parabolic resonance exhibits new type of chaotic behavior which includes instabilities in some directions and long trapping times in others. Moreover, in a degenerate case, near a {\it flat parabolic resonance}, large scale instabilities appear. A model arising from an atmospherical study is shown to exhibit flat parabolic resonance. This supplies a simple mechanism for the transport of particles with {\it small} (i.e. atmospherically relevant) initial velocities from the vicinity of the equator to high latitudes. A modification of the model which allows the development of atmospherical jets unfolds the degeneracy, yet traces of the flat instabilities are clearly observed

Complexity of the Ruminococcus flavefaciens FD-1 cellulosome reflects an expansion of family-related protein-protein interactions

This work was supported in part by the European Union, Area NMP.2013.1.1–2: Self-assembly of naturally occurring nanosystems: CellulosomePlus Project number: 604530, and by the EU Seventh Framework Programme (FP7 2007–2013) under the WallTraC project (Grant Agreement no 263916), and BioStruct-X (grant agreement no 283570). This paper reflects the author’s views only. The European Community is not liable for any use that may be made of the information contained herein. CMGAF is also supported by Fundação para a Ciência e a Tecnologia (Lisbon, Portugal) through grants PTDC/BIA-PRO/103980/2008 and EXPL/BIA-MIC/1176/2012. EAB is also funded by a grant (No. 1349/13) from the Israel Science Foundation (ISF), Jerusalem, Israel and by a grant (No. 2013284) from the U.S.-Israel Binational Science Foundation (BSF). E.A.B. is the incumbent of The Maynard I. and Elaine Wishner Chair of Bio-organic Chemistry.Peer reviewedPublisher PD

Symmetry breaking perturbations and strange attractors

The asymmetrically forced, damped Duffing oscillator is introduced as a prototype model for analyzing the homoclinic tangle of symmetric dissipative systems with \textit{symmetry breaking} disturbances. Even a slight fixed asymmetry in the perturbation may cause a substantial change in the asymptotic behavior of the system, e.g. transitions from two sided to one sided strange attractors as the other parameters are varied. Moreover, slight asymmetries may cause substantial asymmetries in the relative size of the basins of attraction of the unforced nearly symmetric attracting regions. These changes seems to be associated with homoclinic bifurcations. Numerical evidence indicates that \textit{strange attractors} appear near curves corresponding to specific secondary homoclinic bifurcations. These curves are found using analytical perturbational tools

Migrant African women: tales of agency and belonging

This paper explores issues of belonging and agency among asylum seekers and refugee women of African origin in the UK. It discusses the ways these women engendered resistance in their everyday life to destitution, lack of cultural recognition, and gender inequality through the foundation of their own non-governmental organization, African Women’s Empowerment Forum, AWEF, a collective ‘home’ space. The focus of this account is on migrant women’s agency and self-determination for the exercise of choice to be active actors in society. It points to what might be an important phenomenon on how local grassroots movements are challenging the invisibility of asylum seekers’ and refugees’ lives and expanding the notion of politics to embrace a wider notion of community politics with solidarity. AWEF is the embodiment of a social space that resonates the ‘in-between’ experience of migrant life providing stability to the women members regarding political and community identification

Effects of exemestane and letrozole therapy on plasma concentrations of estrogens in a randomized trial of postmenopausal women with breast cancer

PURPOSE: Inter-individual differences in estrogen concentrations during treatment with aromatase inhibitors (AIs) may contribute to therapeutic response and toxicity. The aim of this study was to determine plasma concentrations of estradiol (E2), estrone (E1), and estrone sulfate (E1S) in a large cohort of AI-treated breast cancer patients. METHODS: In a randomized, multicenter trial of postmenopausal women with early-stage breast cancer starting treatment with letrozole (n = 241) or exemestane (n = 228), plasma estrogen concentrations at baseline and after 3 months were quantitated using a sensitive mass spectrometry-based assay. Concentrations and suppression below the lower limit of quantification (LLOQ) were compared between estrogens and between drugs. RESULTS: The ranges of baseline estrogen concentrations were <LLOQ-361 pg/mL for E2, <LLOQ-190 pg/mL for E1, and 8.3-4060 pg/mL for E1S. For E2, the frequency of suppression below the LLOQ was not statistically significantly different between AIs (exemestane: 89.0%, letrozole: 86.9%, p = 0.51). However, patients on letrozole were more likely to achieve suppression below the LLOQ of both E1 (exemestane: 80.1%, letrozole: 90.1%, p = 0.005) and E1S (exemestane: 17.4%, letrozole: 54.9%, p = 4.34e-15). After 3 months of AI therapy, the ranges of estrogen concentrations were <LLOQ-63.8 pg/mL, <LLOQ-36.7 pg/mL, and <LLOQ-1090 pg/mL for E2, E1, and E1S, respectively. During treatment, 16 patients had an increased concentration compared to the baseline concentration of at least one estrogen. CONCLUSIONS: Letrozole had greater suppression of plasma E1 and E1S than exemestane, though the response was highly variable among patients. Additional research is required to examine the clinical relevance of differential estrogen suppression

Brucellosis remains a neglected disease inthe developing world: a call forinterdisciplinary action

Brucellosis places significant burdens on the human healthcare system and limits the economic growth of individuals, communities, and nations where such development is especially important to diminish the prevalence of poverty. The implementation of public policy focused on mitigating the socioeconomic effects of brucellosis in human and animal populations is desperately needed. When developing a plan to mitigate the associated consequences, it is vital to consider both the abstract and quantifiable effects. This requires an interdisciplinary and collaborative, or One Health, approach that consists of public education, the development of an infrastructure for disease surveillance and reporting in both veterinary and medical fields, and campaigns for control in livestock and wildlife species

Tumor and serum DNA methylation in women receiving preoperative chemotherapy with or without vorinostat in TBCRC008

BACKGROUND: Methylated gene markers have shown promise in predicting breast cancer outcomes and treatment response. We evaluated whether baseline and changes in tissue and serum methylation levels would predict pathological complete response (pCR) in patients with HER2-negative early breast cancer undergoing preoperative chemotherapy. METHODS: The TBCRC008 trial investigated pCR following 12 weeks of preoperative carboplatin and albumin-bound paclitaxel + vorinostat/placebo (n = 62). We measured methylation of a 10-gene panel by quantitative multiplex methylation-specific polymerase chain reaction and expressed results as cumulative methylation index (CMI). We evaluated association between CMI level [baseline, day 15 (D15), and change] and pCR using univariate and multivariable logistic regression models controlling for treatment and hormone receptor (HR) status, and performed exploratory subgroup analyses. RESULTS: In univariate analysis, one log unit increase in tissue CMI levels at D15 was associated with 40% lower chance of obtaining pCR (odds ratio, OR 0.60, 95% CI 0.37-0.97; p = 0.037). Subgroup analyses suggested a significant association between tissue D15 CMI levels and pCR in vorinostat-treated [OR 0.44 (0.20, 0.93), p = 0.03], but not placebo-treated patients. CONCLUSION: In this study investigating the predictive roles of tissue and serum CMI levels in patients with early breast cancer for the first time, we demonstrate that high D15 tissue CMI levels may predict poor response. Larger studies and improved analytical procedures to detect methylated gene markers in early stage breast cancer are needed. TBCRC008 is registered on ClinicalTrials.gov (NCT00616967)