109 research outputs found
Analysis of Different Types of Regret in Continuous Noisy Optimization
The performance measure of an algorithm is a crucial part of its analysis.
The performance can be determined by the study on the convergence rate of the
algorithm in question. It is necessary to study some (hopefully convergent)
sequence that will measure how "good" is the approximated optimum compared to
the real optimum. The concept of Regret is widely used in the bandit literature
for assessing the performance of an algorithm. The same concept is also used in
the framework of optimization algorithms, sometimes under other names or
without a specific name. And the numerical evaluation of convergence rate of
noisy algorithms often involves approximations of regrets. We discuss here two
types of approximations of Simple Regret used in practice for the evaluation of
algorithms for noisy optimization. We use specific algorithms of different
nature and the noisy sphere function to show the following results. The
approximation of Simple Regret, termed here Approximate Simple Regret, used in
some optimization testbeds, fails to estimate the Simple Regret convergence
rate. We also discuss a recent new approximation of Simple Regret, that we term
Robust Simple Regret, and show its advantages and disadvantages.Comment: Genetic and Evolutionary Computation Conference 2016, Jul 2016,
Denver, United States. 201
Current diversity of Phytophthora infestans infecting cultivated potato in the Peruvian Andes
Late blight caused by P. infestans is the most devastating disease of potato worldwide. To understand the current P. infestans population structure in the Peruvian Andes, 701 single-lesion samples were collected from cultivated potato in different agroecological zones at 2016-2017. Genetic diversity was analyzed using the 12-plex SSR markers kit and mtADN. Phenotypic diversity was characterized for mating type, metalaxyl resistance and virulence. SSR analysis showed that population consists of EC-1 and PE-3 clonal lineages variants, that have the mtADN IIa and Ia, respectively. All isolates were A1 mating type. 94% of the EC-1 variant isolates were resistant to metalaxil, whereas the sensitive proportion (47%) in the PE-3 variants was bigger than the resistant (35%). Furthermore, virulence assays detected 41 complex physiological races from 142 selected isolates, the most frequent physiological race was 1,3,4,7,10,11 in both EC-1 and PE-3 variants. Phylogenetic analysis evidenced that isolates share identical SSR genotypes and physiological races in distant regions, that suggests that migration could have occurred. Additionally, no detection of A2 mating type indicate that population reproduction must be asexual. EC-1 clonal lineage continues to dominate across the Peruvian Andes, since 91% of the isolates were variants of this clonal lineage. The US-1 clonal lineage reported at 2001, appears to be displaced as it was no longer detected infecting cultivated potato
Clinical characteristics of bacterial vaginosis among women testing positive for fastidious bacteria
The making of the oral microbiome in Agta hunterâgatherers
Ecological and genetic factors have influenced the composition of the human microbiome during our evolutionary history. We analysed the oral microbiota of the Agta, a hunterâgatherer population where some members have adopted an agricultural diet. We show that age is the strongest factor modulating the microbiome, probably through immunosenescence since we identified an increase in the number of species classified as pathogens with age. We also characterised biological and cultural processes generating sexual dimorphism in the oral microbiome. A small subset of oral bacteria is influenced by the host genome, linking host collagen genes to bacterial biofilm formation. Our data also suggest that shifting from a fish/meat diet to a rice-rich diet transforms their microbiome, mirroring the Neolithic transition. All of these factors have implications in the epidemiology of oral diseases. Thus, the human oral microbiome is multifactorial and shaped by various ecological and social factors that modify the oral environment
Agta hunterâgatherer oral microbiomes are shaped by contact network structure
Here we investigate the effects of extensive sociality and mobility on the oral microbiome of 138 Agta hunterâgatherers from the Philippines. Our comparisons of microbiome composition showed that the Agta are more similar to Central African BaYaka hunterâgatherers than to neighbouring farmers. We also defined the Agta social microbiome as a set of 137 oral bacteria (only 7% of 1980 amplicon sequence variants) significantly influenced by social contact (quantified through wireless sensors of short-range interactions). We show that large interaction networks including strong links between close kin, spouses and even unrelated friends can significantly predict bacterial transmission networks across Agta camps. Finally, we show that more central individuals to social networks are also bacterial supersharers. We conclude that hunterâgatherer social microbiomes are predominantly pathogenic and were shaped by evolutionary tradeoffs between extensive sociality and disease spread
Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and meta-analysis
Objective: To determine the effectiveness and degree of implementation of interventions for the control of Aedes aegypti in Latin America and the Caribbean (LAC) as reported in scientific literature. Methods: We searched MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS, for experimental and observational studies, economic assessments and qualitative experiences carried out in LAC from 2000 to 2016. We assessed incidence and morbimortality of Aedes aegypti-related diseases and entomological indices: Breteau (containers), House, and Pupae per Person. We used GRADE methodology for assessing quality of evidence. Results: Of 1826 records retrieved, 75 were included and 9 cluster randomised clinical trials could be meta-analysed. We did not identify any intervention supported by a high certainty of evidence. In consistency with qualitative evidence, health education and community engagement probably reduces the entomological indices, as do the use of insecticide-treated materials, indoor residual spraying and the management of containers. There is low certainty of evidence supporting the use of ovitraps or larvitraps, and the integrated epidemiological surveillance strategy to improve indices and reduce the incidence of dengue. The reported degree of implementation of these vector control interventions was variable and most did not extend to whole cities and were not sustained beyond 2 years. Conclusions: We found a general lack of evidence on effectiveness of vector control in the region, despite a few interventions that showed moderate to low certainty of evidence. It is important to engage and educate the community, apart from achieving the implementation of integrated actions between the health and other sectors at national and regional level.Fil: Bardach, Ariel Esteban. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; ArgentinaFil: GarcĂa Perdomo, Herney AndrĂ©s. Universidad del Valle; ColombiaFil: Alcaraz, Andrea. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Tapia LĂłpez, Elena. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Ruano Gandara, Ruth Amanda. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Ruvinsky, Silvina. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂa "Juan P. Garrahan"; ArgentinaFil: Ciapponi, AgustĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; Argentin
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Heterogeneity of Dengue Illness in Community-Based Prospective Study, Iquitos, Peru
Measuring heterogeneity of dengue illness is necessary to define suitable endpoints in dengue vaccine and therapeutic trials and will help clarify behavioral responses to illness. To quantify heterogeneity in dengue illness, including milder cases, we developed the Dengue Illness Perceptions Response (IPR) survey, which captured detailed symptom data, including intensity, duration, and character, and change in routine activities caused by illness. During 2016â2019, we collected IPR data daily during the acute phase of illness for 79 persons with a positive reverse transcription PCR result for dengue virus RNA. Most participants had mild ambulatory disease. However, we measured substantial heterogeneity in illness experience, symptom duration, and maximum reported intensity of individual symptoms. Symptom intensity was a more valuable predicter of major activity change during dengue illness than symptom presence or absence alone. These data suggest that the IPR measures clinically useful heterogeneity in dengue illness experience and its relation to altered human behavior
The impact of dengue illness on social distancing and caregiving behavior
Background
Human mobility among residential locations can drive dengue virus (DENV) transmission dynamics. Recently, it was shown that individuals with symptomatic DENV infection exhibit significant changes in their mobility patterns, spending more time at home during illness. This change in mobility is predicted to increase the risk of acquiring infection for those living with or visiting the ill individual. It has yet to be considered, however, whether social contacts are also changing their mobility, either by socially distancing themselves from the infectious individual or increasing contact to help care for them. Social, or physical, distancing and caregiving could have diverse yet important impacts on DENV transmission dynamics; therefore, it is necessary to better understand the nature and frequency of these behaviors including their effect on mobility.
Methodology and principal findings
Through community-based febrile illness surveillance and RT-PCR infection confirmation, 67 DENV positive (DENV+) residents were identified in the city of Iquitos, Peru. Using retrospective interviews, data were collected on visitors and home-based care received during the illness. While 15% of participants lost visitors during their illness, 22% gained visitors; overall, 32% of all individuals (particularly females) received visitors while symptomatic. Caregiving was common (90%), particularly caring by housemates (91%) and caring for children (98%). Twenty-eight percent of caregivers changed their behavior enough to have their work (and, likely, mobility patterns) affected. This was significantly more likely when caring for individuals with low âhealth-related quality of well-beingâ during illness (Fisherâs Exact, p = 0.01).
Conclusions/Significance
Our study demonstrates that social contacts of individuals with dengue modify their patterns of visitation and caregiving. The observed mobility changes could impact a susceptible individualâs exposure to virus or a presymptomatic/clinically inapparent individualâs contribution to onward transmission. Accounting for changes in social contact mobility is imperative in order to get a more accurate understanding of DENV transmission
Co-encapsulation of human serum albumin and superparamagnetic iron oxide in PLGA nanoparticles: Part I. Effect of process variables on the mean size
PLGA (poly d,l-lactic-co-glycolic acid) nanoparticles (NPs) encapsulating magnetite nanoparticles (MNPs) along with a model drug human serum albumin (HSA) were prepared by double emulsion solvent evaporation method. This Part I will focus on size and size distribution of prepared NPs, whereas encapsulation efficiency will be discussed in Part II. It was found that mean hydrodynamic particle size was influenced by five important process variables. To explore their effects, a five-factorial, three-level experimental design and statistical analysis were carried out using STATISTICAÂź software. Effect of process variables on the mean size of nanoparticles was investigated and finally conditions to minimize size of NPs were proposed. GAMSâą/MINOS software was used for optimization. The mean hydrodynamic size of nanoparticles ranged from 115 to 329ânm depending on the process conditions. Smallest possible mean particle size can be achieved by using low polymer concentration and high dispersion energy (enough sonication time) along with small aqueous/organic volume ratio
Agta hunterâgatherer oral microbiomes are shaped by contact network structure
Here we investigate the effects of extensive sociality and mobility on the oral microbiome of 138 Agta hunterâgatherers from the Philippines. Our comparisons of microbiome composition showed that the Agta are more similar to Central African BaYaka hunterâgatherers than to neighbouring farmers. We also defined the Agta social microbiome as a set of 137 oral bacteria (only 7% of 1980 amplicon sequence variants) significantly influenced by social contact (quantified through wireless sensors of short-range interactions). We show that large interaction networks including strong links between close kin, spouses and even unrelated friends can significantly predict bacterial transmission networks across Agta camps. Finally, we show that more central individuals to social networks are also bacterial supersharers. We conclude that hunterâgatherer social microbiomes are predominantly pathogenic and were shaped by evolutionary tradeoffs between extensive sociality and disease spread
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