Riviste scientifiche

AI binges on CSI crime shows and learns to guess whodunnit

New Scientist - Me, 08/11/2017 - 17:35
Predicting the twists and turns of a crime drama are hard enough for us - teaching computers to do it will make them better at understanding complex scenarios

Maths can make sense of Trump’s ‘madman’ North Korea strategy

New Scientist - Me, 08/11/2017 - 15:30
Outlandish threats in the standoff between North Korea and Donald Trump are bluffs whose main aim is to bolster support at home, says game theorist Petros Sekeris

How YouTube Kids can solve its Peppa Pig cannibalism problem

New Scientist - Me, 08/11/2017 - 14:24
When a flesh-eating Peppa Pig ends up on a channel for young viewers, it means YouTube must put its house in order, say Charlie Beckett and Sonia Livingstone

Sheep learn to recognise celebrity faces from different angles

New Scientist - Me, 08/11/2017 - 01:01
The animals were as good as humans at recognising mugshots of the same celebs from different angles, showing sophisticated brain processing of imagery

Cardiovascular disease (CVD) and chronic kidney disease (CKD) event rates in HIV-positive persons at high predicted CVD and CKD risk: A prospective analysis of the D:A:D observational study

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Mark A. Boyd, Amanda Mocroft, Lene Ryom, Antonella d’Arminio Monforte, Caroline Sabin, Wafaa M. El-Sadr, Camilla Ingrid Hatleberg, Stephane De Wit, Rainer Weber, Eric Fontas, Andrew Phillips, Fabrice Bonnet, Peter Reiss, Jens Lundgren, Matthew Law

Background

The Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study has developed predictive risk scores for cardiovascular disease (CVD) and chronic kidney disease (CKD, defined as confirmed estimated glomerular filtration rate [eGFR] ≤ 60 ml/min/1.73 m2) events in HIV-positive people. We hypothesized that participants in D:A:D at high (>5%) predicted risk for both CVD and CKD would be at even greater risk for CVD and CKD events.

Methods and findings

We included all participants with complete risk factor (covariate) data, baseline eGFR > 60 ml/min/1.73 m2, and a confirmed (>3 months apart) eGFR < 60 ml/min/1.73 m2 thereafter to calculate CVD and CKD risk scores. We calculated CVD and CKD event rates by predicted 5-year CVD and CKD risk groups (≤1%, >1%–5%, >5%) and fitted Poisson models to assess whether CVD and CKD risk group effects were multiplicative. A total of 27,215 participants contributed 202,034 person-years of follow-up: 74% male, median (IQR) age 42 (36, 49) years, median (IQR) baseline year of follow-up 2005 (2004, 2008). D:A:D risk equations predicted 3,560 (13.1%) participants at high CVD risk, 4,996 (18.4%) participants at high CKD risk, and 1,585 (5.8%) participants at both high CKD and high CVD risk. CVD and CKD event rates by predicted risk group were multiplicative. Participants at high CVD risk had a 5.63-fold (95% CI 4.47, 7.09, p < 0.001) increase in CKD events compared to those at low risk; participants at high CKD risk had a 1.31-fold (95% CI 1.09, 1.56, p = 0.005) increase in CVD events compared to those at low risk. Participants’ CVD and CKD risk groups had multiplicative predictive effects, with no evidence of an interaction (p = 0.329 and p = 0.291 for CKD and CVD, respectively). The main study limitation is the difference in the ascertainment of the clinically defined CVD endpoints and the laboratory-defined CKD endpoints.

Conclusions

We found that people at high predicted risk for both CVD and CKD have substantially greater risks for both CVD and CKD events compared with those at low predicted risk for both outcomes, and compared to those at high predicted risk for only CVD or CKD events. This suggests that CVD and CKD risk in HIV-positive persons should be assessed together. The results further encourage clinicians to prioritise addressing modifiable risks for CVD and CKD in HIV-positive people.

HIV prevalence and behavioral and psychosocial factors among transgender women and cisgender men who have sex with men in 8 African countries: A cross-sectional analysis

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Tonia Poteat, Benjamin Ackerman, Daouda Diouf, Nuha Ceesay, Tampose Mothopeng, Ky-Zerbo Odette, Seni Kouanda, Henri Gautier Ouedraogo, Anato Simplice, Abo Kouame, Zandile Mnisi, Gift Trapence, L. Leigh Ann van der Merwe, Vicente Jumbe, Stefan Baral

Introduction

Sub-Saharan Africa bears more than two-thirds of the worldwide burden of HIV; however, data among transgender women from the region are sparse. Transgender women across the world face significant vulnerability to HIV. This analysis aimed to assess HIV prevalence as well as psychosocial and behavioral drivers of HIV infection among transgender women compared with cisgender (non-transgender) men who have sex with men (cis-MSM) in 8 sub-Saharan African countries.

Methods and findings

Respondent-driven sampling targeted cis-MSM for enrollment. Data collection took place at 14 sites across 8 countries: Burkina Faso (January–August 2013), Côte d’Ivoire (March 2015–February 2016), The Gambia (July–December 2011), Lesotho (February–September 2014), Malawi (July 2011–March 2012), Senegal (February–November 2015), Swaziland (August–December 2011), and Togo (January–June 2013). Surveys gathered information on sexual orientation, gender identity, stigma, mental health, sexual behavior, and HIV testing. Rapid tests for HIV were conducted. Data were merged, and mixed effects logistic regression models were used to estimate relationships between gender identity and HIV infection. Among 4,586 participants assigned male sex at birth, 937 (20%) identified as transgender or female, and 3,649 were cis-MSM. The mean age of study participants was approximately 24 years, with no difference between transgender participants and cis-MSM. Compared to cis-MSM participants, transgender women were more likely to experience family exclusion (odds ratio [OR] 1.75, 95% CI 1.42–2.16, p < 0.001), rape (OR 1.95, 95% CI 1.63–2.36, p < 0.001), and depressive symptoms (OR 1.30, 95% CI 1.12–1.52, p < 0.001). Transgender women were more likely to report condomless receptive anal sex in the prior 12 months (OR 2.44, 95% CI 2.05–2.90, p < 0.001) and to be currently living with HIV (OR 1.81, 95% CI 1.49–2.19, p < 0.001). Overall HIV prevalence was 25% (235/926) in transgender women and 14% (505/3,594) in cis-MSM. When adjusted for age, condomless receptive anal sex, depression, interpersonal stigma, law enforcement stigma, and violence, and the interaction of gender with condomless receptive anal sex, the odds of HIV infection for transgender women were 2.2 times greater than the odds for cis-MSM (95% CI 1.65–2.87, p < 0.001). Limitations of the study included sampling strategies tailored for cis-MSM and merging of datasets with non-identical survey instruments.

Conclusions

In this study in sub-Saharan Africa, we found that HIV burden and stigma differed between transgender women and cis-MSM, indicating a need to address gender diversity within HIV research and programs.

Reaching global HIV/AIDS goals: What got us here, won't get us there

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Wafaa M. El-Sadr, Katherine Harripersaud, Miriam Rabkin

In a Perspective, Wafaa El-Sadr and colleagues discuss tailored approaches to treatment and prevention of HIV infection.

Effectiveness of a combination strategy for linkage and retention in adult HIV care in Swaziland: The Link4Health cluster randomized trial

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Margaret L. McNairy, Matthew R. Lamb, Averie B. Gachuhi, Harriet Nuwagaba-Biribonwoha, Sean Burke, Sikhathele Mazibuko, Velephi Okello, Peter Ehrenkranz, Ruben Sahabo, Wafaa M. El-Sadr

Background

Gaps in the HIV care continuum contribute to poor health outcomes and increase HIV transmission. A combination of interventions targeting multiple steps in the continuum is needed to achieve the full beneficial impact of HIV treatment.

Methods and findings

Link4Health, a cluster-randomized controlled trial, evaluated the effectiveness of a combination intervention strategy (CIS) versus the standard of care (SOC) on the primary outcome of linkage to care within 1 month plus retention in care at 12 months after HIV-positive testing. Ten clusters of HIV clinics in Swaziland were randomized 1:1 to CIS versus SOC. The CIS included point-of-care CD4+ testing at the time of an HIV-positive test, accelerated antiretroviral therapy (ART) initiation for treatment-eligible participants, mobile phone appointment reminders, health educational packages, and noncash financial incentives. Secondary outcomes included each component of the primary outcome, mean time to linkage, assessment for ART eligibility, ART initiation and time to ART initiation, viral suppression defined as HIV-1 RNA < 1,000 copies/mL at 12 months after HIV testing among patients on ART ≥6 months, and loss to follow-up and death at 12 months after HIV testing. A total of 2,197 adults aged ≥18 years, newly tested HIV positive, were enrolled from 19 August 2013 to 21 November 2014 (1,096 CIS arm; 1,101 SOC arm) and followed for 12 months. The median participant age was 31 years (IQR 26–39), and 59% were women. In an intention-to-treat analysis, 64% (705/1,096) of participants at the CIS sites achieved the primary outcome versus 43% (477/1,101) at the SOC sites (adjusted relative risk [RR] 1.52, 95% CI 1.19–1.96, p = 0.002). Participants in the CIS arm versus the SOC arm had the following secondary outcomes: linkage to care regardless of retention at 12 months (RR 1.08, 95% CI 0.97–1.21, p = 0.13), mean time to linkage (2.5 days versus 7.5 days, p = 0.189), retention in care at 12 months regardless of time to linkage (RR 1.48, 95% CI 1.18–1.86, p = 0.002), assessment for ART eligibility (RR 1.20, 95% CI 1.07–1.34, p = 0.004), ART initiation (RR 1.16, 95% CI 0.96–1.40, p = 0.12), mean time to ART initiation from time of HIV testing (7 days versus 14 days, p < 0.001), viral suppression among those on ART for ≥6 months (RR 0.97, 95% CI 0.88–1.07, p = 0.55), loss to follow-up at 12 months after HIV testing (RR 0.56, 95% CI 0.40–0.79, p = 0.002), and death (N = 78) within 12 months of HIV testing (RR 0.80, 95% CI 0.46–1.35, p = 0.41). Limitations of this study include a small number of clusters and the inability to evaluate the incremental effectiveness of individual components of the combination strategy.

Conclusions

A combination strategy inclusive of 5 evidence-based interventions aimed at multiple steps in the HIV care continuum was associated with significant increase in linkage to care plus 12-month retention. This strategy offers promise of enhanced outcomes for HIV-positive patients.

Trial registration

ClinicalTrials.gov NCT01904994.

Measuring success: The challenge of social protection in helping eliminate tuberculosis

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Priya B. Shete, David W. Dowdy

In this Perspective on the research article by William Rudgard and colleagues, Priya Shete and coauthor discuss the challenges of measuring the impact of social protection programs such as cash transfers.

Comparison of two cash transfer strategies to prevent catastrophic costs for poor tuberculosis-affected households in low- and middle-income countries: An economic modelling study

PLoS Medicine - Ma, 07/11/2017 - 23:00

by William E. Rudgard, Carlton A. Evans, Sedona Sweeney, Tom Wingfield, Knut Lönnroth, Draurio Barreira, Delia Boccia

Background

Illness-related costs for patients with tuberculosis (TB) ≥20% of pre-illness annual household income predict adverse treatment outcomes and have been termed “catastrophic.” Social protection initiatives, including cash transfers, are endorsed to help prevent catastrophic costs. With this aim, cash transfers may either be provided to defray TB-related costs of households with a confirmed TB diagnosis (termed a “TB-specific” approach); or to increase income of households with high TB risk to strengthen their economic resilience (termed a “TB-sensitive” approach). The impact of cash transfers provided with each of these approaches might vary. We undertook an economic modelling study from the patient perspective to compare the potential of these 2 cash transfer approaches to prevent catastrophic costs.

Methods and findings

Model inputs for 7 low- and middle-income countries (Brazil, Colombia, Ecuador, Ghana, Mexico, Tanzania, and Yemen) were retrieved by literature review and included countries' mean patient TB-related costs, mean household income, mean cash transfers, and estimated TB-specific and TB-sensitive target populations. Analyses were completed for drug-susceptible (DS) TB-related costs in all 7 out of 7 countries, and additionally for drug-resistant (DR) TB-related costs in 1 of the 7 countries with available data. All cost data were reported in 2013 international dollars ($). The target population for TB-specific cash transfers was poor households with a confirmed TB diagnosis, and for TB-sensitive cash transfers was poor households already targeted by countries’ established poverty-reduction cash transfer programme. Cash transfers offered in countries, unrelated to TB, ranged from $217 to $1,091/year/household. Before cash transfers, DS TB-related costs were catastrophic in 6 out of 7 countries. If cash transfers were provided with a TB-specific approach, alone they would be insufficient to prevent DS TB catastrophic costs in 4 out of 6 countries, and when increased enough to prevent DS TB catastrophic costs would require a budget between $3.8 million (95% CI: $3.8 million–$3.8 million) and $75 million (95% CI: $50 million–$100 million) per country. If instead cash transfers were provided with a TB-sensitive approach, alone they would be insufficient to prevent DS TB-related catastrophic costs in any of the 6 countries, and when increased enough to prevent DS TB catastrophic costs would require a budget between $298 million (95% CI: $219 million–$378 million) and $165,367 million (95% CI: $134,085 million–$196,425 million) per country. DR TB-related costs were catastrophic before and after TB-specific or TB-sensitive cash transfers in 1 out of 1 countries. Sensitivity analyses showed our findings to be robust to imputation of missing TB-related cost components, and use of 10% or 30% instead of 20% as the threshold for measuring catastrophic costs. Key limitations were using national average data and not considering other health and social benefits of cash transfers.

Conclusions

A TB-sensitive cash transfer approach to increase all poor households’ income may have broad benefits by reducing poverty, but is unlikely to be as effective or affordable for preventing TB catastrophic costs as a TB-specific cash transfer approach to defray TB-related costs only in poor households with a confirmed TB diagnosis. Preventing DR TB-related catastrophic costs will require considerable additional investment whether a TB-sensitive or a TB-specific cash transfer approach is used.

HIV-1 persistence following extremely early initiation of antiretroviral therapy (ART) during acute HIV-1 infection: An observational study

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Timothy J. Henrich, Hiroyu Hatano, Oliver Bacon, Louise E. Hogan, Rachel Rutishauser, Alison Hill, Mary F. Kearney, Elizabeth M. Anderson, Susan P. Buchbinder, Stephanie E. Cohen, Mohamed Abdel-Mohsen, Christopher W. Pohlmeyer, Remi Fromentin, Rebecca Hoh, Albert Y. Liu, Joseph M. McCune, Jonathan Spindler, Kelly Metcalf-Pate, Kristen S. Hobbs, Cassandra Thanh, Erica A. Gibson, Daniel R. Kuritzkes, Robert F. Siliciano, Richard W. Price, Douglas D. Richman, Nicolas Chomont, Janet D. Siliciano, John W. Mellors, Steven A. Yukl, Joel N. Blankson, Teri Liegler, Steven G. Deeks

Background

It is unknown if extremely early initiation of antiretroviral therapy (ART) may lead to long-term ART-free HIV remission or cure. As a result, we studied 2 individuals recruited from a pre-exposure prophylaxis (PrEP) program who started prophylactic ART an estimated 10 days (Participant A; 54-year-old male) and 12 days (Participant B; 31-year-old male) after infection with peak plasma HIV RNA of 220 copies/mL and 3,343 copies/mL, respectively. Extensive testing of blood and tissue for HIV persistence was performed, and PrEP Participant A underwent analytical treatment interruption (ATI) following 32 weeks of continuous ART.

Methods and findings

Colorectal and lymph node tissues, bone marrow, cerebral spinal fluid (CSF), plasma, and very large numbers of peripheral blood mononuclear cells (PBMCs) were obtained longitudinally from both participants and were studied for HIV persistence in several laboratories using molecular and culture-based detection methods, including a murine viral outgrowth assay (mVOA). Both participants initiated PrEP with tenofovir/emtricitabine during very early Fiebig stage I (detectable plasma HIV-1 RNA, antibody negative) followed by 4-drug ART intensification. Following peak viral loads, both participants experienced full suppression of HIV-1 plasma viremia. Over the following 2 years, no further HIV could be detected in blood or tissue from PrEP Participant A despite extensive sampling from ileum, rectum, lymph nodes, bone marrow, CSF, circulating CD4+ T cell subsets, and plasma. No HIV was detected from tissues obtained from PrEP Participant B, but low-level HIV RNA or DNA was intermittently detected from various CD4+ T cell subsets. Over 500 million CD4+ T cells were assayed from both participants in a humanized mouse outgrowth assay. Three of 8 mice infused with CD4+ T cells from PrEP Participant B developed viremia (50 million input cells/surviving mouse), but only 1 of 10 mice infused with CD4+ T cells from PrEP Participant A (53 million input cells/mouse) experienced very low level viremia (201 copies/mL); sequence confirmation was unsuccessful. PrEP Participant A stopped ART and remained aviremic for 7.4 months, rebounding with HIV RNA of 36 copies/mL that rose to 59,805 copies/mL 6 days later. ART was restarted promptly. Rebound plasma HIV sequences were identical to those obtained during acute infection by single-genome sequencing. Mathematical modeling predicted that the latent reservoir size was approximately 200 cells prior to ATI and that only around 1% of individuals with a similar HIV burden may achieve lifelong ART-free remission. Furthermore, we observed that lymphocytes expressing the tumor marker CD30 increased in frequency weeks to months prior to detectable HIV-1 RNA in plasma. This study was limited by the small sample size, which was a result of the rarity of individuals presenting during hyperacute infection.

Conclusions

We report HIV relapse despite initiation of ART at one of the earliest stages of acute HIV infection possible. Near complete or complete loss of detectable HIV in blood and tissues did not lead to indefinite ART-free HIV remission. However, the small numbers of latently infected cells in individuals treated during hyperacute infection may be associated with prolonged ART-free remission.

Contemporary disengagement from antiretroviral therapy in Khayelitsha, South Africa: A cohort study

PLoS Medicine - Ma, 07/11/2017 - 23:00

by Samantha R. Kaplan, Christa Oosthuizen, Kathryn Stinson, Francesca Little, Jonathan Euvrard, Michael Schomaker, Meg Osler, Katherine Hilderbrand, Andrew Boulle, Graeme Meintjes

Background

Retention in care is an essential component of meeting the UNAIDS “90-90-90” HIV treatment targets. In Khayelitsha township (population ~500,000) in Cape Town, South Africa, more than 50,000 patients have received antiretroviral therapy (ART) since the inception of this public-sector program in 2001. Disengagement from care remains an important challenge. We sought to determine the incidence of and risk factors associated with disengagement from care during 2013–2014 and outcomes for those who disengaged.

Methods and findings

We conducted a retrospective cohort study of all patients ≥10 years of age who visited 1 of the 13 Khayelitsha ART clinics from 2013–2014 regardless of the date they initiated ART. We described the cumulative incidence of first disengagement (>180 days not attending clinic) between 1 January 2013 and 31 December 2014 using competing risks methods, enabling us to estimate disengagement incidence up to 10 years after ART initiation. We also described risk factors for disengagement based on a Cox proportional hazards model, using multiple imputation for missing data. We ascertained outcomes (death, return to care, hospital admission, other hospital contact, alive but not in care, no information) after disengagement until 30 June 2015 using province-wide health databases and the National Death Registry. Of 39,884 patients meeting our eligibility criteria, the median time on ART to 31 December 2014 was 33.6 months (IQR 12.4–63.2). Of the total study cohort, 592 (1.5%) died in the study period, 1,231 (3.1%) formally transferred out, 987 (2.5%) were silent transfers and visited another Western Cape province clinic within 180 days, 9,005 (22.6%) disengaged, and 28,069 (70.4%) remained in care. Cumulative incidence of disengagement from care was estimated to be 25.1% by 2 years and 50.3% by 5 years on ART. Key factors associated with disengagement (age, male sex, pregnancy at ART start [HR 1.58, 95% CI 1.47–1.69], most recent CD4 count) and retention (ART club membership, baseline CD4) after adjustment were similar to those found in previous studies; however, notably, the higher hazard of disengagement soon after starting ART was no longer present after adjusting for these risk factors. Of the 9,005 who disengaged, the 2 most common initial outcomes were return to ART care after 180 days (33%; n = 2,976) and being alive but not in care in the Western Cape (25%; n = 2,255). After disengagement, a total of 1,459 (16%) patients were hospitalized and 237 (3%) died. The median follow-up from date of disengagement to 30 June 2015 was 16.7 months (IQR 11–22.4). As we included only patient follow-up from 2013–2014 by design in order to maximize the generalizability of our findings to current programs, this limited our ability to more fully describe temporal trends in first disengagement.

Conclusions

Twenty-three percent of ART patients in the large cohort of Khayelitsha, one of the oldest public-sector ART programs in South Africa, disengaged from care at least once in a contemporary 2-year period. Fifty-eight percent of these patients either subsequently returned to care (some “silently”) or remained alive without hospitalization, suggesting that many who are considered “lost” actually return to care, and that misclassification of “lost” patients is likely common in similar urban populations.A challenge to meeting ART retention targets is developing, testing, and implementing program designs to target mobile populations and retain them in lifelong care. This should be guided by risk factors for disengagement and improving interlinkage of routine information systems to better support patient care across complex care platforms.

What we’re doing now will make the ocean completely unliveable

New Scientist - Ma, 07/11/2017 - 18:00
Climate change could reduce oxygen levels in the oceans by 40 per cent over the next 8000 years, leading to dramatic changes in marine life

UK is right to worry that tech takeovers may let hackers in

New Scientist - Ma, 07/11/2017 - 17:49
Electronic chips made abroad can be altered to allow foreign powers to disrupt critical infrastructure. Nations are right to fret about it, says Paul Marks

Virtual cocktails hijack your senses to turn water into wine

New Scientist - Ma, 07/11/2017 - 17:10
Using a combination of LEDs, electrodes and smelly gas, the Vocktail can simulate a variety of flavours to create digital drinks

Your brain signals weaken and slow down when you’re really tired

New Scientist - Ma, 07/11/2017 - 17:00
We’ve seen how sleep deprivation disrupts the way neurons communicate with each other, and it may explain why a bad night’s sleep makes it hard to concentrate

Planting trees could mop up ten years’ worth of greenhouse gases

New Scientist - Ma, 07/11/2017 - 16:40
The planet is still warming inexorably, with 2017 set to be one of the three hottest years on record, but a major programme of tree-planting could help cool the world

Bitcoin: what a waste of resources

New Scientist - Ma, 07/11/2017 - 14:00
The cryptocurrency’s insistence on meaningless computer tasks is outdated, profligate and holds the technology back

I went on a data diet and all I got was ads and paranoia 

New Scientist - Ma, 07/11/2017 - 13:00
Tired of your dirty data habits? Here's how to regain control over your privacy and stop leaking more than you need to the big tech companies

We’ve figured out how to ensure quantum computers can be trusted

New Scientist - Ma, 07/11/2017 - 12:54
Quantum computers will be useless if we can't trust their calculations. Now, two teams have programmed quantum systems to detect their own errors
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