Remarks on the k-error linear complexity of p(n)-periodic sequences

Recently the first author presented exact formulas for the number of 2ⁿn-periodic binary sequences with given 1-error linear complexity, and an exact formula for the expected 1-error linear complexity and upper and lower bounds for the expected k-error linear complexity, k >2, of a random 2ⁿn-periodic binary sequence. A crucial role for the analysis played the Chan-Games algorithm. We use a more sophisticated generalization of the Chan-Games algorithm by Ding et al. to obtain exact formulas for the counting function and the expected value for the 1-error linear complexity for pⁿn-periodic sequences over Fp, p prime. Additionally we discuss the calculation of lower and upper bounds on the k-error linear complexity of pⁿn-periodic sequences over Fp

The prediction of fatigue using speech as a biosignal

Automatic systems for estimating operator fatigue have application in safety-critical environments. We develop and evaluate a system to detect fatigue from speech recordings collected from speakers kept awake over a 60-hour period. A binary classification system (fatigued/not-fatigued) based on time spent awake showed good discrimination, with 80 % unweighted accuracy using raw features, and 90 % with speaker-normalized features. We describe the data collection, feature analysis, machine learning and cross-validation used in the study. Results are promising for real-world applications in domains such as aerospace, transportation and mining where operators are in regular verbal communication as part of their normal working activities

On the Computation of the Linear Complexity and the k-Error Linear Complexity of Binary Sequences with Period a Power of Two

The linear Games-Chan algorithm for computing the linear complexity c(s) of a binary sequence s of period ℓ = 2n requires the knowledge of the full sequence, while the quadratic Berlekamp-Massey algorithm only requires knowledge of 2c(s) terms. We show that we can modify the Games-Chan algorithm so that it computes the complexity in linear time knowing only 2c(s) terms. The algorithms of Stamp-Martin and Lauder-Paterson can also be modified, without loss of efficiency, to compute analogues of the k-error linear complexity for finite binary sequences viewed as initial segments of infinite sequences with period a power of two. We also develop an algorithm which, given a constant c and an infinite binary sequence s with period ℓ = 2n, computes the minimum number k of errors (and the associated error sequence) needed over a period of s for bringing the linear complexity of s below c. The algorithm has a time and space bit complexity of O(ℓ). We apply our algorithm to decoding and encoding binary repeated-root cyclic codes of length ℓ in linear, O(ℓ), time and space. A previous decoding algorithm proposed by Lauder and Paterson has O(ℓ(logℓ)2) complexity

Contraceptive Use and Method Preference among Women in Soweto, South Africa: The Influence of Expanding Access to HIV Care and Treatment Services

Objective: Preventing unintended pregnancy among HIV-positive women constitutes a critical and cost-effective approach to primary prevention of mother-to-child transmission of HIV and is a global public health priority for addressing the desperate state of maternal and child health in HIV hyper-endemic settings. We sought to investigate whether the prevalence of contraceptive use and method preferences varied by HIV status and receipt of highly active antiretroviral therapy (HAART) among women in Soweto, South Africa. Methods: We used survey data from 563 sexually active, non-pregnant women (18–44 years) recruited from the Perinatal HIV Research Unit in Soweto (May–December, 2007); 171 women were HIV-positive and receiving HAART (median duration of use = 31 months; IQR = 28, 33), 178 were HIV-positive and HAART-naïve, and 214 were HIV-negative. Medical record review was conducted to confirm HIV status and clinical variables. Logistic regression models estimated adjusted associations between HIV status, receipt of HAART, and contraceptive use. Results: Overall, 78 % of women reported using contraception, with significant variation by HIV status: 86 % of HAART users, 82 % of HAART-naïve women, and 69 % of HIV-negative women (p,0.0001). In adjusted models, compared with HIVnegativ

Gene and protein expression of glucose transporter 1 and glucose transporter 3 in human laryngeal cancer—the relationship with regulatory hypoxia-inducible factor-1α expression, tumor invasiveness, and patient prognosis

Increased glucose uptake mediated by glucose transporters and reliance on glycolysis are common features of malignant cells. Hypoxia-inducible factor-1α supports the adaptation of hypoxic cells by inducing genes related to glucose metabolism. The contribution of glucose transporter (GLUT) and hypoxia-inducible factor-1α (HIF-1α) activity to tumor behavior and their prognostic value in head and neck cancers remains unclear. The aim of this study was to examine the predictive value of GLUT1, GLUT3, and HIF-1α messenger RNA (mRNA)/protein expression as markers of tumor aggressiveness and prognosis in laryngeal cancer. The level of hypoxia/metabolic marker genes was determined in 106 squamous cell laryngeal cancer (SCC) and 73 noncancerous matched mucosa (NCM) controls using quantitative realtime PCR. The related protein levels were analyzed by Western blot. Positive expression of SLC2A1, SLC2A3, and HIF-1α genes was noted in 83.9, 82.1, and 71.7 % of SCC specimens and in 34.4, 59.4, and 62.5 % of laryngeal cancer samples. Higher levels of mRNA/protein for GLUT1 and HIF-1α were noted in SCC compared to NCM (p<0.05). SLC2A1 was found to have a positive relationship with grade, tumor front grading (TFG) score, and depth and mode of invasion (p<0.05). SLC2A3 was related to grade and invasion type (p<0.05). There were also relationships of HIF-1α with pTNM, TFG scale, invasion depth and mode, tumor recurrences, and overall survival (p<0.05). In addition, more advanced tumors were found to be more likely to demonstrate positive expression of these proteins. In conclusion, the hypoxia/metabolic markers studied could be used as molecular markers of tumor invasiveness in laryngeal cancer.This work was supported, in part, by the statutory fund of the Department of Cytobiochemistry, University of Łódź, Poland (506/811), and by grant fromtheNational Science Council, Poland (N403 043 32/2326)

Psychosocial Challenges Facing Women Living with HIV During the Perinatal Period in Rural Uganda

The complexities of navigating pregnancy while living with HIV predispose women to additional stress. Finding ways to minimize psychosocial challenges during the perinatal period may maximize the well-being of mothers living with HIV and their children. The goal of this study was to explore psychosocial challenges experienced by women living with HIV (WLWH) during pregnancy and the postpartum. We conducted individual in-depth interviews with 20 WLWH recruited from an HIV treatment cohort study in Mbarara, Uganda as part of a larger study exploring perinatal depression. We conducted content analyses to identify themes related to challenges of WLWH during pregnancy and the postpartum. Participants had a median age of 33 years [IQR: 28± 35], a median of 3 living children [IQR: 2±5], and 95% had achieved HIV-RNA suppression. Challenges were organized around the following themes: HIV -related stigma from health professionals, HIV status disclosure dilemma, unintended pregnancy and intimate partner violence, HIV and environmental structural barriers and distress and fear related to maternal and child health. Stigma centered on discrimination by health care professionals and personal shame associated with being pregnant as a WLWH. This led to difficulty engaging in HIV care, particularly when coupled with structural barriers, such as lack of transportation to clinic. Participants experienced intimate partner violence and lacked support from their partners and family members. Distress and fear about the health and uncertainty about the future of the unborn baby due to maternal deteriorating physical health was common. The perinatal period is a time of stress for WLWH. Challenges experienced by WLWH may compromise successful engagement in HIV care and may reduce quality of life for women and their children. Strategies aimed at alleviating the challenges of WLWH should involve the larger structural environment including partners, family and community member as well as policy makers, funders and program implementers to work together for the common cause. These consolidated efforts may not only lower the risk of psychological distress but has potential to create long lasting solutions to benefit the wider community

“I Always Worry about What Might Happen Ahead”: Implementing Safer Conception Services in the Current Environment of Reproductive Counseling for HIV-Affected Men and Women in Uganda

We explored healthcare provider perspectives and practices regarding safer conception counseling for HIV-affected clients. Methods. We conducted semistructured interviews with 38 providers (medical and clinical officers, nurses, peer counselors, and village health workers) delivering care to HIV-infected clients across 5 healthcare centres in Mbarara District, Uganda. Interview transcripts were analyzed using content analysis. Results. Of 38 providers, 76% were women with median age 34 years (range 24–57). First, we discuss providers\u27 reproductive counseling practices. Emergent themes include that providers (1) assess reproductive goals of HIV-infected female clients frequently, but infrequently for male clients; (2) offer counseling focused on "family planning" and maternal and child health; (3) empathize with the importance of having children for HIV-affected clients; and (4) describe opportunities to counsel HIV-serodiscordant couples. Second, we discuss provider-level challenges that impede safer conception counseling. Emergent themes included the following: (1) providers struggle to translate reproductive rights language into individualized risk reduction given concerns about maternal health and HIV transmission and (2) providers lack safer conception training and support needed to provide counseling. Discussion. Tailored guidelines and training are required for providers to implement safer conception counseling. Such support must respond to provider experiences with adverse HIV-related maternal and child outcomes and a national emphasis on pregnancy prevention

Depression During Pregnancy and the Postpartum Among HIV-Infected Women on Antiretroviral Therapy in Uganda

Background: Among HIV-infected women, perinatal depression compromises clinical, maternal, and child health outcomes. Antiretroviral therapy (ART) is associated with lower depression symptom severity but the uniformity of effect through pregnancy and postpartum periods is unknown. Methods: We analyzed prospective data from 447 HIV-infected women (18–49 years) initiating ART in rural Uganda (2005–2012). Participants completed blood work and comprehensive questionnaires quarterly. Pregnancy status was assessed by self-report. Analysis time periods were defined as currently pregnant, postpartum (0–12 months post-pregnancy outcome), or non–pregnancy-related. Depression symptom severity was measured using a modified Hopkins Symptom Checklist 15, with scores ranging from 1 to 4. Probable depression was defined as >1.75. Linear regression with generalized estimating equations was used to compare mean depression scores over the 3 periods. Results: At enrollment, median age was 32 years (interquartile range: 27–37), median CD4 count was 160 cells per cubic millimeter (interquartile range: 95–245), and mean depression score was 1.75 (s = 0.58) (39% with probable depression). Over 4.1 median years of follow-up, 104 women experienced 151 pregnancies. Mean depression scores did not differ across the time periods (P = 0.75). Multivariable models yielded similar findings. Increasing time on ART, viral suppression, better physical health, and “never married” were independently associated with lower mean depression scores. Findings were consistent when assessing probable depression. Conclusions: Although the lack of association between depression and perinatal periods is reassuring, high depression prevalence at treatment initiation and continued incidence across pregnancy and non–pregnancy-related periods of follow-up highlight the critical need for mental health services for HIV-infected women to optimize both maternal and perinatal health