The population of persons living with HIV (PLWH) is growing older and more prone to developing other chronic health conditions. Disease progression has been shown to be related to quality of life. However, descriptions of chronic comorbid illnesses and the unique quality of life challenges of older adults living with HIV are not well understood and have not been examined in multiple geographic locations. 452 PLWH aged 50 years or older were recruited from AIDS Service Organizations in 9 states. Participants completed a telephone survey that included measures of other chronic health conditions, perceived stress, depression and health related quality of life. 94% of the sample reported a chronic health condition in addition to HIV (mode = 2). The highest reported conditions were hypertension, chronic pain, hepatitis, and arthritis. Despite relatively high rates of depression, overall quality of life was moderately high for the sample. Physical functioning was most impacted by the addition of other chronic health problems. Social functioning, mental health functioning, stress and depression were also strongly associated with chronic disease burden. Additional chronic health problems are the norm for PLWH aged 50 years and older. Quality of life is significantly related to the addition of chronic health problems. As increasing numbers of PLWH reach older age, this raises challenges for providing comprehensive healthcare to older PLWH with multiple chronic conditions.

For time series exhibiting strong periodicities, standard (linear) surrogate methods are not useful. We describe a new algorithm that can test against the null hypothesis of a periodic orbit with uncorrelated noise. We demonstrate the application of this method to artificial data and experimental time series, including human electrocardiogram recordings during sinus rhythm and ventricular tachycardia. DOI: 10.1103/PhysRevLett.87.188101 PACS numbers: 05.45.Tp, 05.10. -a, 87.19.Nn The method of surrogate data [1] is widely applied to test the null hypothesis that an observed time series is a typical realization of the output of a specific class of dynamical systems. This method is widely used in the analysis of experimental time series and provides a powerful tool in the search for determinism in apparently stochastic data. However, the current surrogate techniques have very limited utility when applied to a time series with a strong pseudoperiodic behavior.The surrogate algorithm we describe in this Letter generates pseudoperiodic surrogates (PPS). This method is based on the well-known local-linear modeling methods described by Mees [2] and Sugihara and May [3]. Previously, Small and Judd advocated [4] and implemented [5] nonlinear radial basis modeling routines [6,7] as a form of surrogate hypothesis testing. The method we describe here is simpler and tests a more specific null hypothesis. This method may be applied to test against the null hypothesis of a periodic orbit with uncorrelated noise in the very large number of experimental systems that exhibit pseudoperiodic behavior.By contrast, the three most successful, and widely applied, algorithms test for membership of the class of (i) independent and identical distributed (IID) noise processes, (ii) linearly filtered noise processes, and (iii) static monotonic nonlinear transformation of linearly filtered noise processes [1,8]. For time series data exhibiting strong pseudoperiodic behavior, the null hypotheses of IID or colored noise are obviously false. Therefore, apart from serving as a "sanity check," these existing algorithms are of limited use for such data.For a pseudoperiodic time series, Theiler and Rapp suggested an alternative algorithm [9]: cycle shuffled surrogates. Analogously to IID noise surrogates, cycle shuffled surrogates are produced by shuffling the individual cycles within a time series. Hence, intracycle dynamics are preserved but intercycle dynamics are not. However, even with this new approach Theiler noted spurious long term correlations in the autocorrelation plot [9] for cycle shuffled surrogates. Furthermore, if the peak or troughs do not occur at precisely the same values, surrogates generated by this method are not able to preserve both stationarity and continuity. By shifting individual cycles vertically, individual cycles can be matched and continuity will be preserved. However, such a transformation introduces nonstationarity in the surrogates that is absent in the original.Each of these techniques is commonly applied to...

Cancer and its treatment can lead to a myriad of adverse events and negatively impact quality of life of older cancer patients and survivors. Unmet physical activity needs vary across the cancer continuum and remain an important yet understudied area of research in this population. Exercise interventions have been shown to be effective in treating both the physical and psychological declines associated with cancer and its treatment, with a potential to improve cancer-related outcomes. Despite the current evidence, exercise is clearly underutilized due to several barriers and knowledge gaps in existing trials that include appropriate population identification, design, and outcome measures selection. The benefits of regular exercise in both the primary and secondary prevention of chronic conditions are well established in the non-cancer population. In older cancer patients and survivors, further research is needed before exercise gains widespread acceptance. The Cancer and Aging Research Group convened experts in exercise, aging and cancer to evaluate current scientific evidence and knowledge gaps in geriatric exercise oncology. This report summarizes these findings and provides future research directions.

We describe an efficient algorithm which computes the Gaussian kernel correlation integral from noisy time series; this is subsequently used to estimate the underlying correlation dimension and noise level in the noisy data. The algorithm first decomposes the integral core into two separate calculations, reducing computing time from O(N2xN(b)) to O(N2+N(2)(b)). With other further improvements, this algorithm can speed up the calculation of the Gaussian kernel correlation integral by a factor of gamma approximately (2-10)N(b). We use typical examples to demonstrate the use of the improved Gaussian kernel algorithm.

The physical assumptions underlying the static and dynamic Jiles-Atherton (JA) hysteresis models are critically analyzed. It is shown that the energy-balance method used in deriving these models is actually closer to a balance of coenergies, thereby depriving the resulting JA phenomenology of physical meaning. The non-physical basis of its dynamic extension is demonstrated by a sharp contrast between hysteresis loops predicted by the model and those measured for grain-oriented steel under conditions of controlled sinusoidal flux density at frequencies of 50, 100, and 200 Hz.

Nutritional issues among older adults with cancer are an understudied area of research despite significant prognostic implications for treatment side effects, cancer-specific mortality, and overall survival. In May of 2015, the National Cancer Institute and the National Institute on Aging co-sponsored a conference focused on future directions in geriatric oncology research. Nutritional research among older adults with cancer was highlighted as a major area of concern as most nutritional cancer research has been conducted among younger adults, with limited evidence to guide the care of nutritional issues among older adults with cancer. Cancer diagnoses among older adults are increasing, and the care of the older adult with cancer is complicated due to multimorbidity, heterogeneous functional status, polypharmacy, deficits in cognitive and mental health, and several other non-cancer factors. Due to this complexity, nutritional needs are dynamic, multifaceted, and dependent on the clinical scenario. This manuscript outlines the proceedings of this conference including knowledge gaps and recommendations for future nutritional research among older adults with cancer. Three common clinical scenarios encountered by oncologists include (1) weight loss during anti-cancer therapy, (2) malnutrition during advanced disease, and (3) obesity during survivorship. In this manuscript, we provide a brief overview of relevant cancer literature within these three areas, knowledge gaps that exist, and recommendations for future research.

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These findings suggest that HRT use is associated with improved survival from colon cancer. Future observational and laboratory studies should shed light on how hormones may be related to reduced incidence and improved prognosis.