Racial categories in machine learning

Controversies around race and machine learning have sparked debate among computer scientists over how to design machine learning systems that guarantee fairness. These debates rarely engage with how racial identity is embedded in our social experience, making for sociological and psychological complexity. This complexity challenges the paradigm of considering fairness to be a formal property of supervised learning with respect to protected personal attributes. Racial identity is not simply a personal subjective quality. For people labeled "Black" it is an ascribed political category that has consequences for social differentiation embedded in systemic patterns of social inequality achieved through both social and spatial segregation. In the United States, racial classification can best be understood as a system of inherently unequal status categories that places whites as the most privileged category while signifying the Negro/black category as stigmatized. Social stigma is reinforced through the unequal distribution of societal rewards and goods along racial lines that is reinforced by state, corporate, and civic institutions and practices. This creates a dilemma for society and designers: be blind to racial group disparities and thereby reify racialized social inequality by no longer measuring systemic inequality, or be conscious of racial categories in a way that itself reifies race. We propose a third option. By preceding group fairness interventions with unsupervised learning to dynamically detect patterns of segregation, machine learning systems can mitigate the root cause of social disparities, social segregation and stratification, without further anchoring status categories of disadvantage

Influencia de los aditivos acelerantes de fragua sobre la resistencia a la compresión y tiempo de fraguado de un concreto realizado bajo clima cálido Trujillo, 2019

La construcción es considerada a nivel mundial dentro de las actividades económicas más demandantes de mano de obra y ejerce un efecto multiplicador en la economía, ya que es uno de los sectores productivos que más aporta al crecimiento de los países y regiones. En el Perú los aditivos químicos se introdujeron aproximadamente a fines de la década de los años 50. En la década siguiente, se introdujeron los primeros aditivos superplastificantes, revolucionando la tecnología del concreto en esa época, ya que se crearon concretos fluidos y de alta resistencia para la construcción de elementos esbeltos y de fina apariencia. Las variaciones climáticas tienen gran influencia en el comportamiento de la mezcla cuando no se hace uso de aditivos. Cuando depende solo del concreto, éste puede estar trabajando en un sitio cálido y a las dos horas ya no sirve la mezcla; sin embargo, en un sitio frío, pueden pasan más de ocho horas y este no llega a endurecer. El uso de aditivos en el concreto se ha vuelto muy frecuente en la actualidad, debido a que el concreto con aditivos nos da resultados que no pueden ser logrados por otros métodos y de forma tan económica; esto se debe a que, el uso de aditivos acelerantes en la elaboración de concreto origina una reducción en el tiempo de fraguado y mejores resultados en la resistencia a la compresión del concreto a edades tempranas. De acuerdo a lo señalado anteriormente, es necesario realizar un estudio general del comportamiento de los aditivos acelerantes con la finalidad de brindar la confianza suficiente para su aplicación. Los aditivos contribuyen a mejorar algunas de las propiedades del concreto, por lo que mejoran su calidad con un incremento en el costo por metro cúbico de mezcla. Sin embargo, este aumento se ve reflejado en la facilidad de manipulación y calidad que se obtiene al emplearlos. Debido a estos motivos es que se propone investigar más a fondo sobre la resistencia a la compresión del concreto empleando distintas marcas de aditivos acelerantes, para poder hacer un análisis de los resultados

Common polymorphic variation in the genetically diverse African insulin gene and its association with size at birth.

The insulin variable number of tandem repeats (INS VNTR) has been variably associated with size at birth in non-African populations. Small size at birth is a major determinant of neonatal mortality, so the INS VNTR may influence survival. We tested the hypothesis, therefore, that genetic variation around the INS VNTR in a rural Gambian population, who experience seasonal variation in nutrition and subsequently birth weight, may be associated with foetal and early growth. Six polymorphisms flanking the INS VNTR were genotyped in over 2,500 people. Significant associations were detected between the maternally inherited SNP 27 (rs689) allele and birth length [effect size 17.5 (5.2-29.8) mm; P = 0.004; n = 361]. Significant associations were also found between the maternally inherited African-specific SNP 28 (rs5506) allele and post-natal weight gain [effect size 0.19 (0.05-0.32) z score points/year; P = 0.005; n = 728). These results suggest that in the Gambian population studied there are associations between polymorphic variation in the genetically diverse INS gene and foetal and early growth characteristics, which contribute to overall polygenic associations with these traits

FTO gene variation and measures of body mass in an African population

BACKGROUND: Variation in the fat mass and obesity associated (FTO) gene has been reproducibly associated with body mass index (BMI) and obesity in populations of White European origin. Data from Asians and African-Americans is less conclusive. METHODS: We assessed the effect of 16 FTO polymorphisms on body mass in a large population of predominantly lean Gambians (N(max) 2208) participating in a long-term surveillance program providing contemporary and early-life anthropometric measurements. RESULTS: Sixteen FTO tagSNPs screened here, including several associated with BMI in Europeans, were not associated with birth weight (BWT), early weight gain in 1-2 year olds, BMI in adults (> or = 18 y), or weight-for-height (WFH) z-score across all ages. No association was seen between genotype and WFH z-score or other measures of body mass. The confidence limits indicate that the effect size for WFH z-score never exceeded 0.17 units per allele copy for any SNP (excluding the three SNPs with allele < 15%). with much the lowest allele frequency. The confidence interval of the effect size for rs9939609 did not overlap that reported previously in Europeans. CONCLUSION: To our knowledge this is the first study of FTO gene variation in a well-characterised African population. Our results suggest that FTO gene variation does not influence measures of body mass in Gambians living a traditional lifestyle, or has a smaller effect than that detected in Europeans. These findings are not directly comparable to results from previous studies in African-Americans due to differences in study design and analysis. It is also possible that any effect of FTO genotype on body mass is of limited relevance in a lean population where little excess food is available, compared to similar ethnic populations where food supply is plentiful

Periconceptional multiple-micronutrient supplementation and placental function in rural Gambian women: a double-blind, randomized, placebo-controlled trial

BACKGROUND: Maternal micronutrient deficiencies are commonly associated with clinical indicators of placental dysfunction. OBJECTIVE: We tested the hypothesis that periconceptional multiple-micronutrient supplementation (MMS) affects placental function. DESIGN: We conducted a double-blind, randomized, placebo-controlled trial of MMS in 17- to 45-y-old Gambian women who were menstruating regularly and within the previous 3 mo. Eligible subjects were pre-randomly assigned to supplementation with the UNICEF/WHO/United Nations University multiple micronutrient preparation (UNIMMAP) or placebo on recruitment and until they reached their first antenatal check-up or for 1 y if they failed to conceive. Primary outcome measures were midgestational indexes of utero-placental vascular-endothelial function [ratio of plasminogen-activator inhibitor (PAI) 1 to PAI-2 and mean uterine-artery resistance index (UtARI)] and placental active transport capacity at delivery [fetal to maternal measles antibody (MMA) ratio]. RESULTS: We recruited 1156 women who yielded 415 pregnancies, of which 376 met all of the inclusion criteria. With adjustment for gestational age at sampling, there were no differences in PAI-1 to PAI-2 or MMA ratios between trial arms, but there was a 0.02-unit reduction in UtARI between 18 and 32 wk of gestation (95% CI: -0.03, -0.00; P = 0.040) in women taking UNIMMAP. CONCLUSIONS: Placental vascular function was modifiable by periconceptional micronutrient supplementation. However, the effect was small and supplementation did not further affect other variables of placental function. This trial was registered at www.controlled-trials.com as ISRCTN 13687662

The dynamics of nasopharyngeal streptococcus pneumoniae carriage among rural Gambian mother-infant pairs

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is an important cause of community acquired pneumonia, sepsis, meningitis and otitis media globally and has been incriminated as a major cause of serious childhood bacterial infections in The Gambia. Better understanding of the dynamics of transmission and carriage will inform control strategies.</p> <p>Methods</p> <p>This study was conducted among 196 mother-infant pairs recruited at birth from six villages in the West Kiang region of The Gambia. Nasopharyngeal swabs were collected from mother-infant pairs at birth (within 12 hours of delivery), 2, 5 and 12 months. Standard techniques of culture were used to identify carriage and serotype <it>S. pneumoniae</it>.</p> <p>Results</p> <p>Of 46 serotypes identified, the 6 most common, 6A, 6B, 14, 15, 19F and 23F, accounted for 67.3% of the isolates from infants. Carriage of any serotype among infants rose from 1.5% at birth to plateau at approximately 80% by 2 m (prevalence at 2 m = 77%; 5 m = 86%; 12 m = 78%). Likewise, maternal carriage almost doubled in the first 2 months post-partum and remained elevated for the next 10 m (prevalence at birth = 13%; 2 m = 24%; 5 m = 22%; 12 m = 21%). Carriage was significantly seasonal in both infants and mothers with a peak in December and lowest transmission in August. The total number of different serotypes we isolated from each infant varied and less than would be expected had the serotypes assorted independently. In contrast, this variability was much as expected among mothers. The half-life of a serotype colony was estimated to be 1.90 m (CI_95%: 1.66-2.21) in infants and 0.75 m (CI_95%: 0.55-1.19) in mothers. While the odds for a serotype to be isolated from an infant increased by 9-fold if it had also been isolated from the mother, the population attributable fraction (PAF) of pneumococcal carriage in infants due to maternal carriage was only 9.5%. Some marked differences in dynamics were observed between vaccine and non-vaccine serotypes.</p> <p>Conclusions</p> <p>Colonisation of the nasopharynx in Gambian infants by <it>S. pneumoniae </it>is rapid and highly dynamic. Immunity or inter-serotype competition may play a role in the dynamics. Reducing mother-infant transmission would have a minimal effect on infant carriage.</p

TELEMORPH: BANDWIDTH-DETERMINED MOBILE MULTIMODAL PRESENTATION

This article presents the initial stages of research at the University of Ulster into a mobile intelligent multimedia presentation system called TeleMorph. TeleMorph aims to dynamically generate multimedia presentations using output modalities that are determined by the bandwidth available on a mobile device’s wireless connection. To demonstrate the effectiveness of this research, TeleTuras, a tourist information guide for the city of Derry, will implement the solution provided by TeleMorph, thus demonstrating its effectiveness. This article does not focus on the multimodal content composition but rather concentrates on the motivation for and issues surrounding such intelligent tourist systems. Key words: Mobile intelligent multimedia; Intelligent multimedia generation and presentation; Intelligent tourist interface