26 research outputs found
The Internet of Things Has a Gateway Problem
The vision of an Internet of Things (IoT) has captured the imag-ination of the world and raised billions of dollars, all before we stopped to deeply consider how all these Things should connect to the Internet. The current state-of-the-art requires application-layer gateways both in software and hardware that provide application-specific connectivity to IoT devices. In much the same way that it would be difficult to imagine requiring a new web browser for each website, it is hard to imagine our current approach to IoT connec-tivity scaling to support the IoT vision. The IoT gateway problem exists in part because today’s gateways conflate network connectiv-ity, in-network processing, and user interface functions. We believe that disentangling these functions would improve the connectivity potential for IoT devices. To realize the broader vision, we propose an architecture that leverages the increasingly ubiquitous presence of Bluetooth Low Energy radios to connect IoT peripherals to the Internet. In much the same way that WiFi access points revolution-ized laptop utility, we envision that a worldwide deployment of IoT gateways could revolutionize application-agnostic connectivity, thus breaking free from the stove-piped architectures now taking hold. In this paper, we present our proposed architecture, show example applications enabled by it, and explore research challenges in its implementation and deployment
Increased Nasopharyngeal Density and Concurrent Carriage of Streptococcus Pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis Are Associated with Pneumonia in Febrile Children.
We assessed nasopharyngeal (NP) carriage of five pathogens in febrile children with and without acute respiratory infection (ARI) of the upper (URTI) or lower tract, attending health facilities in Tanzania. NP swabs collected from children (N = 960) aged 2 months to 10 years, and with a temperature ≥38°C, were utilized to quantify bacterial density of S. pneumoniae (Sp), H. influenzae (Hi), M. catarrhalis (Mc), S. aureus (Sa), and N. meningitidis (Nm). We determined associations between presence of individual species, densities, or concurrent carriage of all species combination with respiratory diseases including clinical pneumonia, pneumonia with normal chest radiography (CXR) and endpoint pneumonia. Individual carriage, and NP density, of Sp, Hi, or Mc, but not Sa, or Nm, was significantly associated with febrile ARI and clinical pneumonia when compared to febrile non-ARI episodes. Density was also significantly increased in severe pneumonia when compared to mild URTI (Sp, p<0.002; Hi p<0.001; Mc, p = 0.014). Accordingly, concurrent carriage of Sp+, Hi+, and Mc+, in the absence of Sa- and Nm-, was significantly more prevalent in children with ARI (p = 0.03), or clinical pneumonia (p<0.001) than non-ARI, and in children with clinical pneumonia (p = 0.0007) than URTI. Furthermore, Sp+, Hi+, and Mc+ differentiated children with pneumonia with normal CXR, or endpoint pneumonia, from those with URTI, and non-ARI cases. Concurrent NP carriage of Sp, Hi, and Mc was a predictor of clinical pneumonia and identified children with pneumonia with normal CXR and endpoint pneumonia from those with febrile URTI, or non-ARI episodes
Impact of Experimental Human Pneumococcal Carriage on Nasopharyngeal Bacterial Densities in Healthy Adults
Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary precursor to pneumococcal diseases that result in morbidity and mortality worldwide. The nasopharynx is also host to other bacterial species, including the common pathogens Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis. To better understand how these bacteria change in relation to pneumococcal colonization, we used species-specific quantitative PCR to examine bacterial densities in 52 subjects 7 days before, and 2, 7, and 14 days after controlled inoculation of healthy human adults with S. pneumoniae serotype 6B. Overall, 33 (63%) of subjects carried S. pneumoniae post-inoculation. The baseline presence and density of S. aureus, H. influenzae, and M. catarrhalis were not statistically associated with likelihood of successful pneumococcal colonization at this study’s sample size, although a lower rate of pneumococcal colonization in the presence of S. aureus (7/14) was seen compared to that in the presence of H. influenzae (12/16). Among subjects colonized with pneumococci, the number also carrying either H. influenzae or S. aureus fell during the study and at 14 days post-inoculation, the proportion carrying S. aureus was significantly lower among those who were colonized with S. pneumoniae (p = 0.008) compared to non-colonized subjects. These data on bacterial associations are the first to be reported surrounding experimental human pneumococcal colonization and show that co-colonizing effects are likely subtle rather than absolute
Cost-Effectiveness of Treating Multidrug-Resistant Tuberculosis
BACKGROUND: Despite the existence of effective drug treatments, tuberculosis (TB) causes 2 million deaths annually worldwide. Effective treatment is complicated by multidrug-resistant TB (MDR TB) strains that respond only to second-line drugs. We projected the health benefits and cost-effectiveness of using drug susceptibility testing and second-line drugs in a lower-middle-income setting with high levels of MDR TB. METHODS AND FINDINGS: We developed a dynamic state-transition model of TB. In a base case analysis, the model was calibrated to approximate the TB epidemic in Peru, a setting with a smear-positive TB incidence of 120 per 100,000 and 4.5% MDR TB among prevalent cases. Secondary analyses considered other settings. The following strategies were evaluated: first-line drugs administered under directly observed therapy (DOTS), locally standardized second-line drugs for previously treated cases (STR1), locally standardized second-line drugs for previously treated cases with test-confirmed MDR TB (STR2), comprehensive drug susceptibility testing and individualized treatment for previously treated cases (ITR1), and comprehensive drug susceptibility testing and individualized treatment for all cases (ITR2). Outcomes were costs per TB death averted and costs per quality-adjusted life year (QALY) gained. We found that strategies incorporating the use of second-line drug regimens following first-line treatment failure were highly cost-effective compared to strategies using first-line drugs only. In our base case, standardized second-line treatment for confirmed MDR TB cases (STR2) had an incremental cost-effectiveness ratio of 8,700 per averted death) compared to DOTS. Individualized second-line drug treatment for MDR TB following first-line failure (ITR1) provided more benefit at an incremental cost of 12,000 per averted death) compared to STR2. A more aggressive version of the individualized treatment strategy (ITR2), in which both new and previously treated cases are tested for MDR TB, had an incremental cost-effectiveness ratio of 160,000 per averted death) compared to ITR1. The STR2 and ITR1 strategies remained cost-effective under a wide range of alternative assumptions about treatment costs, effectiveness, MDR TB prevalence, and transmission. CONCLUSIONS: Treatment of MDR TB using second-line drugs is highly cost-effective in Peru. In other settings, the attractiveness of strategies using second-line drugs will depend on TB incidence, MDR burden, and the available budget, but simulation results suggest that individualized regimens would be cost-effective in a wide range of situations
Viral and bacterial upper respiratory tract infection in hospital health care workers over time and association with symptoms
Income Inequalities in College Education During and After the Great Recession
Prior research using the Current Population Surveys (CPS) documents a dramatic equalization in U.S. college enrollments based on family income starting in 2014. However, the measurement of income for independent young adults is problematic; we correct for this by imputing their incomes. We complement our re-analysis of CPS data with data from the Panel Study for Income Dynamics-Transition Into Adulthood (PSID-TA). Both datasets show moderate, non-significant reductions in the income gap in college enrollments for cohorts coming of age during and after the Recession. Extending the CPS analysis to examine inequalities during the COVID pandemic, we show more or less unchanged inequalities for the cohort coming of age in 2020. Using the PSID-TA to examine degree attainment, we again find stable income inequalities in obtaining any degree and a BA degree for pre-Recession and Recession-era cohorts
Income Inequalities in College Education During and After the Great Recession
We examine the associations between parental income and college enrollment for cohorts obtaining their high school diploma between 2003 and 2020 and degree attainment for 2003-2012 cohorts.
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The Impact of Early and Recent Life Stress on Trajectories of Inflammatory Biomarkers in a Diverse Sample of Adolescents.
Elevated inflammatory activity is one possible pathway through which exposure to childhood adversity engenders risk for physical and psychiatric illnesses. Limited research has investigated the compounding effects of childhood and adolescent stress exposure on changes in circulating levels of inflammatory biomarkers. This study assessed whether childhood adversity interacted with chronic or acute stress during adolescence to affect the temporal trajectories of five inflammatory biomarkers across at least three blood draws in a diverse sample of adolescents (N = 134; observations = 462). Using multilevel modeling, the interaction of childhood adversity, time, and within-person variance of acute stressors significantly predicted trajectories of higher interleukin-10 levels, controlling for demographics, medication use, and body mass index. Adolescents with high levels of childhood adversity who were exposed to a higher frequency of acute stressors compared to their own average rate of stress exposure consistently had higher levels of IL-10 as they got older, but those with average and below frequency of acute stressors had decreasing trajectories of log IL-10 as they matured. The results demonstrate how events early in life shape biological responses to the adolescent environment. This study also highlights the importance of developmental timing on the bodys enhanced reactivity to acute and sustained stressors following childhood adversity
The adult nasopharyngeal microbiome as a determinant of pneumococcal acquisition
BACKGROUND: Several cohort studies have indicated associations between S. pneumoniae and other microbes in the nasopharynx. To study causal relationships between the nasopharyngeal microbiome and pneumococcal carriage, we employed an experimental human pneumococcal carriage model. Healthy adult volunteers were assessed for pneumococcal carriage by culture of nasal wash samples (NWS). Those without natural pneumococcal carriage received an intranasal pneumococcal inoculation with serotype 6B or 23F. The composition of the nasopharyngeal microbiome was longitudinally studied by 16S rDNA pyrosequencing on NWS collected before and after challenge. RESULTS: Among 40 selected volunteers, 10 were natural carriers and 30 were experimentally challenged. At baseline, five distinct nasopharyngeal microbiome profiles were identified. The phylogenetic distance between microbiomes of natural pneumococcal carriers was particularly large compared to non-carriers. A more diverse microbiome prior to inoculation was associated with the establishment of pneumococcal carriage. Perturbation of microbiome diversity upon pneumococcal challenge was strain specific. Shifts in microbiome profile occurred after pneumococcal exposure, and those volunteers who acquired carriage more often diverted from their original profile. S. pneumoniae was little prominent in the microbiome of pneumococcal carriers. CONCLUSION: Pneumococcal acquisition in healthy adults is more likely to occur in a diverse microbiome and appears to promote microbial heterogeneity