79 research outputs found
Covariance estimation for characteristics of the Current Population Survey
In repeated surveys, the usual survey estimator of a characteristic can be represented as the sum of the true value and a measurement error, where the measurement error is due to sampling. If the sampling units stay in the survey for a fixed finite number of periods, then the sequence of sampling errors, \u[subscript]t, is a moving average. Assuming that the sequence of true values, \x[subscript]t is a realization of a time series, the objective of estimating the covariance structure of the series \x[subscript]t is considered;For the Current Population Survey, a components-of-variance model for the sampling error is estimated. Three components of variance are identified. These are a replicate component that is due to variation between primary sampling units, a permanent component associated with rotation groups within primary sampling units, and a transient component associated with rotation groups within primary sampling units. The replicate component and the permanent rotation group effects are assumed to be constant over time. The transient rotation group effect is assumed to be a third order autoregressive process. Under the 4-8-4 rotation scheme of the Current Population Survey, u[subscript] t is a fifteenth order moving average. Given the covariance function of \u[subscript]t, two estimation procedures of the structure of \x[subscript]t are proposed and applied to data from the Current Population Survey. The first procedure is a frequency domain estimation procedure and the second procedure uses autocovariances;The limiting distribution of the frequency domain estimator is derived. A Monte Carlo study of the estimator for the first order moving average is conducted. The distributional properties of the estimator and the asymptotic results are in reasonable agreement for samples on the order of 100 observations when the parameter is not close to the boundary
Ohio State's Athletic Carbon Offset Plan
ENR 2367This project is an outlined plan to create carbon neutrality in the Ohio State athletics department. Using carbon-offsetting and community service, this plan hopes to reduce the athletic carbon footprint of 3500-tons.Academic Major: Environmental Policy and Decision MakingAcademic Major: Environmental ScienceAcademic Major: Geograph
An aqueous-two phase extraction system for partitioning of anthocyanins from red cabbage
Due to their aesthetic value and positive health effects, anthocyanins as natural colorants have become very attractive in recent years. There is a need to develop simple and effective methods for the separation and purification of these natural pigments. An aqueous two-phase extraction (ATPE) system based on ethanol/ammonium sulfate is employed for the extraction and preliminary purification of anthocyanins from red cabbage. The influence of ethanol, ammonium sulfate, red cabbage amount and pH on the extraction of anthocyanins is investigated. The optimal extraction conditions (27% (v/v) ethanol, 22% (v/v) ammonium sulfate, 2.5% (v/v) anthocaynin extract, and pH 3.0) gave 83.7% of extraction yield for anthocyanins. The flavonoids and phenolics are concentrated at the top phase of ATPE with a yield of 78% and 82.5%, respectively. The sugars also partitioned and concentrated at the bottom phase with a yield of 79.5%. The stability studies showed that anthocyanins are very stable between the temperature range of 40â70 °C and the pH range of 3.0â6.0, respectively. At a temperature of 70 °C and at pH 6.0 nearly more than 70% of anthocyanin yield is obtained. The results indicated that ATPE technique have a great promise for the efficient recovery of anthocyanins and also removing of the impurities such as sugars
Sex-dependent least toxic timing of irinotecan combined with chronomodulated chemotherapy for metastatic colorectal cancer : randomized multicenter
The least toxic time (LTT) of irinotecan varied by up to 8 hours according to sex and genetic background in mice. The translational relevance was investigated within a randomized trial dataset, where no LTT stood out significantly in the whole population.
130 male and 63 female eligible patients with metastatic colorectal cancer were randomized to receive chronomodulated Irinotecan with peak delivery rate at 1 of 6 clock hours staggered by 4 hours on day 1, then fixedâtime chronomodulated FluorouracilâLeucovorinâOxaliplatin for 4 days, q3 weeks. The sexâspecific circadian characteristics of grade (G) 3â4 toxicities were mapped with cosinor and time*sex interactions confirmed with Fisher's exact test.
Baseline characteristics of male or female patients were similar in the six treatment groups. Main grade 3â4 toxicities over six courses were diarrhea (males vs females, 39.2%; vs 46.0%), neutropenia (15.6% vs 15.0%), fatigue (11.5% vs 15.9%), and anorexia (10.0% vs 7.8%). They were reduced following irinotecan peak delivery in the morning for males, but in the afternoon for females, with statistically significant rhythms (P < .05 from cosinor) and sex*timing interactions (Fisher's exact test, diarrhea, P = .023; neutropenia, P = .015; fatigue, P = .062; anorexia, P = .032). Irinotecan timing was most critical for females, with grades 3â4 ranging from 55.2% of the patients (morning) to 29.4% (afternoon) for diarrhea, and from 25.9% (morning) to 0% (afternoon) for neutropenia.
The study results support irinotecan administration in the morning for males and in the afternoon for females, in order to minimize adverse events without impairing efficacy
Antimicrobial resistance in outpatient Escherichia coli urinary isolates in Dakar, Senegal.
International audienceBACKGROUND: Data regarding the evolution of antimicrobial resistance are needed to suggest appropriate empirical treatment of urinary tract infections (UTI) in developing countries. To assess the antimicrobial susceptibility of Escherichia coli, the predominant pathogen in community-acquired UTI, a prospective multicenter study was carried out in Dakar, Senegal. METHODOLOGY: From February 2004 to October 2006, 1010 non-duplicate E. coli strains were collected from four centres. Antimicrobial susceptibility testing was performed using disk diffusion method according to the recommendations of the CA-SFM (2004). RESULTS: Most of the isolates were resistant to amoxicillin (73.1%), amoxicillin-clavulanic acid (67.5%), cephalothin (55.8%), and trimethoprim/sulfamethoxazole (68.1%). Extended spectrum beta-lactamase was detected in 38 strains. The overall resistance rates to nalidixic acid, norfloxacin and ciprofloxacin were 23.9%, 16.4% and 15.5%, respectively. Most of the strains were susceptible to gentamicin, nitrofurantoin and fosfomycin (respective susceptibility rates, 93.8%, 89.9%, and 99.3%). During this period, a significant decrease in sensitivity was observed for cephalothin, fluoroquinolones and trimethoprim/sulfamethoxazole (p<0.001). CONCLUSIONS: These data suggest that trimethoprim/sulfamethoxazole may no longer be used as empirical treatment for community-acquired UTI in Dakar. In order to preserve the activity of fluoroquinolones for future years, alternatives such as fosfomycin or nitrofurantoin should be considered
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Long-Term Intrapatient Evolution During HIV-2 Infection
HIV-2 disease progression and transmission is attenuated compared to HIV-1, yet prospective studies examining HIV-2 intrapatient evolution have been limited. We examined viral sequence evolution in the C2V3C3 region of the viral env gene in 8 HIV-2 infected individuals from Dakar, Senegal, over the course of approximately 10 years. To compare results to HIV-1 infection, we reanalyzed data from our previous study that examined intrapatient evolution in HIV-1 infected individuals from the same population. HIV-2 sequences from early and late timepoints were phylogenetically intermixed for all subjects, and no distinct trends were observed in terms of increases or decreases in fragment size or number of N-linked glycosylation sites. In homologous env C2V3 sequence, rates of viral divergence and diversification were slower in individuals infected with HIV-2 than individuals with HIV-1. This data indicates that viral evolution occurs slowly in HIV-2 infection, which is consistent with the slow disease progression observed in HIV-2 infection, and supports the notion that viral evolution may be a relevant correlate for disease progression
Using web and mobile phone technologies to collect food market prices in Africa. Approaching real-time data and use of crowdsourcing, 2013 - 2016
Large agricultural commodity price swings observed in recent years have made the importance of accessible, timely, accurate and frequently updated price data more obvious. This study investigates the potential of innovative web and mobile phone technologies and alternative data collection methods such as crowdsourcing in order to collect food price data in Africa. The report summarises these experiences through the lessons learned and provides a detailed overview and assessment of different aspects of the collected data that can be of help for the success of future food price collection exercises.JRC.D.4-Economics of Agricultur
Analysis of natural female post-mating responses of Anopheles gambiae and Anopheles coluzzii unravels similarities and differences in their reproductive ecology
Anopheles gambiae and An. coluzzii, the two most important malaria vectors in sub-Saharan Africa, are recently radiated sibling species that are reproductively isolated even in areas of sympatry. In females from these species, sexual transfer of male accessory gland products, including the steroid hormone 20-hydroxyecdysone (20E), induces vast behavioral, physiological, and transcriptional changes that profoundly shape their post-mating ecology, and that may have contributed to the insurgence of post-mating, prezygotic reproductive barriers. As these barriers can be detected by studying transcriptional changes induced by mating, we set out to analyze the post-mating response of An. gambiae and An. coluzzii females captured in natural mating swarms in Burkina Faso. While the molecular pathways shaping short- and long-term mating-induced changes are largely conserved in females from the two species, we unravel significant inter-specific differences that suggest divergent regulation of key reproductive processes such as egg development, processing of seminal secretion, and mating behavior, that may have played a role in reproductive isolation. Interestingly, a number of these changes occur in genes previously shown to be regulated by the sexual transfer of 20E and may be due to divergent utilization of this steroid hormone in the two species
Time-dependent efficacy of checkpoint inhibitor nivolumab : results from a pilot study in patients with metastatic non-small-cell lung cancer
Hypothesis: Prior experimental and human studies have demonstrated the circadian organization of immune cellsâ proliferation, trafficking, and antigen recognition and destruction. Nivolumab targets T(CD8) cells, the functions, and trafficking of which are regulated by circadian clocks, hence suggesting possible daily changes in nivolumabâs efficacy. Worse progression-free survival (PFS), and overall survival (OS) were reported for malignant melanoma patients receiving more than 20% of their immune checkpoint inhibitor infusions after 16:30 as compared to earlier in the day. Methods: Consecutive metastatic non-small-cell cancer (NSCLC) patients received nivolumab (240 mg iv q 2 weeks) at a daily time that was ârandomlyâ allocated for each course on a logistical basis by the day-hospital coordinators. The median time of all nivolumab administrations was computed for each patient. The study population was split into two timing groups based upon the median value of the median treatment times of all patients. CTCAE-toxicity rates, iRECIST-tumor responses, PFS and OS were computed according to nivolumab timing. PFS and OS curves were compared and hazard ratios (HR) were computed for all major categories of characteristics. Multivariable and sensitivity analyses were also performed. Results: The study accrued 95 stage-IV NSCLC patients (PS 0â1, 96%), aged 41â83 years. The majority of nivolumab administrations occurred between 9:27 and 12:54 for 48 patients (âmorningâ group) and between 12:55 and 17:14 for the other 47 (âafternoonâ group). Median PFS (95% CL) was 11.3 months (5.5â17.1) for the âmorningâ group and 3.1 months (1.5â4.6) for the âafternoonâ one (p < 0.001). Median OS was 34.2 months (15.1â53.3) and 9.6 months (4.9â14.4) for the âmorningâ group and the âafternoonâ one, respectively (p < 0.001). Multivariable analyses identified âmorningâ timing as a significant predictor of longer PFS and OS, with respective HR values of 0.26 (0.11â0.58) and 0.17 (0.08â0.37). The timing effect was consistent across all patient subgroups tested. Conclusions: Nivolumab was nearly four times as effective following âmorningâ as compared to âafternoonâ dosing in this cohort of NSCLC patients. Prospective timing-studies are needed to minimize the risk of resistance and to maximize the benefits from immune checkpoint inhibitors
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