Riviste scientifiche

Traumatic beetle sex causes rapid evolutionary arms race

New Scientist - %age fa
Male seed beetles use sharp spikes on their penises to damage females during sex, but females are evolving thicker tissue to resist them

The brain starts to eat itself after chronic sleep deprivation

New Scientist - %age fa
Sleep loss in mice sends the brain’s immune cells into overdrive. This might be helpful in the short term, but could increase the risk of dementia in the long run

Impact evaluation of different cash-based intervention modalities on child and maternal nutritional status in Sindh Province, Pakistan, at 6 mo and at 1 y: A cluster randomised controlled trial

PLoS Medicine - Ma, 23/05/2017 - 23:00

by Bridget Fenn, Tim Colbourn, Carmel Dolan, Silke Pietzsch, Murtaza Sangrasi, Jeremy Shoham

Background

Cash-based interventions (CBIs), offer an interesting opportunity to prevent increases in wasting in humanitarian aid settings. However, questions remain as to the impact of CBIs on nutritional status and, therefore, how to incorporate them into emergency programmes to maximise their success in terms of improved nutritional outcomes. This study evaluated the effects of three different CBI modalities on nutritional outcomes in children under 5 y of age at 6 mo and at 1 y.

Methods and findings

We conducted a four-arm parallel longitudinal cluster randomised controlled trial in 114 villages in Dadu District, Pakistan. The study included poor and very poor households (n = 2,496) with one or more children aged 6–48 mo (n = 3,584) at baseline. All four arms had equal access to an Action Against Hunger–supported programme. The three intervention arms were as follows: standard cash (SC), a cash transfer of 1,500 Pakistani rupees (PKR) (approximately US$14; 1 PKR = US$0.009543); double cash (DC), a cash transfer of 3,000 PKR; or a fresh food voucher (FFV) of 1,500 PKR; the cash or voucher amount was given every month over six consecutive months. The control group (CG) received no specific cash-related interventions. The median total household income for the study sample was 8,075 PKR (approximately US$77) at baseline. We hypothesized that, compared to the CG in each case, FFVs would be more effective than SC, and that DC would be more effective than SC—both at 6 mo and at 1 y—for reducing the risk of child wasting. Primary outcomes of interest were prevalence of being wasted (weight-for-height z-score [WHZ] < −2) and mean WHZ at 6 mo and at 1 y.The odds of a child being wasted were significantly lower in the DC arm after 6 mo (odds ratio [OR] = 0.52; 95% CI 0.29, 0.92; p = 0.02) compared to the CG. Mean WHZ significantly improved in both the FFV and DC arms at 6 mo (FFV: z-score = 0.16; 95% CI 0.05, 0.26; p = 0.004; DC: z-score = 0.11; 95% CI 0.00, 0.21; p = 0.05) compared to the CG. Significant differences on the primary outcome were seen only at 6 mo. All three intervention groups showed similar significantly lower odds of being stunted (height-for-age z-score [HAZ] < −2) at 6 mo (DC: OR = 0.39; 95% CI 0.24, 0.64; p < 0.001; FFV: OR = 0.41; 95% CI 0.25, 0.67; p < 0.001; SC: OR = 0.36; 95% CI 0.22, 0.59; p < 0.001) and at 1 y (DC: OR = 0.53; 95% CI 0.35, 0.82; p = 0.004; FFV: OR = 0.48; 95% CI 0.31, 0.73; p = 0.001; SC: OR = 0.54; 95% CI 0.36, 0.81; p = 0.003) compared to the CG. Significant improvements in height-for-age outcomes were also seen for severe stunting (HAZ < −3) and mean HAZ. An unintended outcome was observed in the FFV arm: a negative intervention effect on mean haemoglobin (Hb) status (−2.6 g/l; 95% CI −4.5, −0.8; p = 0.005). Limitations of this study included the inability to mask participants or data collectors to the different interventions, the potentially restrictive nature of the FFVs, not being able to measure a threshold effect for the two different cash amounts or compare the different quantities of food consumed, and data collection challenges given the difficult environment in which this study was set.

Conclusions

In this setting, the amount of cash given was important. The larger cash transfer had the greatest effect on wasting, but only at 6 mo. Impacts at both 6 mo and at 1 y were seen for height-based growth variables regardless of the intervention modality, indicating a trend toward nutrition resilience. Purchasing restrictions applied to food-based voucher transfers could have unintended effects, and their use needs to be carefully planned to avoid this.

Trial registration

ISRCTN registry ISRCTN10761532

Data sharing in clinical trials: An experience with two large cancer screening trials

PLoS Medicine - Ma, 23/05/2017 - 23:00

by Claire S. Zhu, Paul F. Pinsky, James E. Moler, Andrew Kukwa, Jerome Mabie, Joshua M. Rathmell, Tom Riley, Philip C. Prorok, Christine D. Berg

Paul Pinsky of the US National Cancer Institute and colleagues describe the implementation and outcomes of web-based data sharing from the PLCO and NLST cancer screening trials.

Measuring personal beliefs and perceived norms about intimate partner violence: Population-based survey experiment in rural Uganda

PLoS Medicine - Ma, 23/05/2017 - 23:00

by Alexander C. Tsai, Bernard Kakuhikire, Jessica M. Perkins, Dagmar Vořechovská, Amy Q. McDonough, Elizabeth L. Ogburn, Jordan M. Downey, David R. Bangsberg

Background

Demographic and Health Surveys (DHS) conducted throughout sub-Saharan Africa indicate there is widespread acceptance of intimate partner violence, contributing to an adverse health risk environment for women. While qualitative studies suggest important limitations in the accuracy of the DHS methods used to elicit attitudes toward intimate partner violence, to date there has been little experimental evidence from sub-Saharan Africa that can be brought to bear on this issue.

Methods and findings

We embedded a randomized survey experiment in a population-based survey of 1,334 adult men and women living in Nyakabare Parish, Mbarara, Uganda. The primary outcomes were participants’ personal beliefs about the acceptability of intimate partner violence and perceived norms about intimate partner violence in the community. To elicit participants’ personal beliefs and perceived norms, we asked about the acceptability of intimate partner violence in five different vignettes. Study participants were randomly assigned to one of three survey instruments, each of which contained varying levels of detail about the extent to which the wife depicted in the vignette intentionally or unintentionally violated gendered standards of behavior. For the questions about personal beliefs, the mean (standard deviation) number of items where intimate partner violence was endorsed as acceptable was 1.26 (1.58) among participants assigned to the DHS-style survey variant (which contained little contextual detail about the wife’s intentions), 2.74 (1.81) among participants assigned to the survey variant depicting the wife as intentionally violating gendered standards of behavior, and 0.77 (1.19) among participants assigned to the survey variant depicting the wife as unintentionally violating these standards. In a partial proportional odds regression model adjusting for sex and village of residence, with participants assigned to the DHS-style survey variant as the referent group, participants assigned the survey variant that depicted the wife as intentionally violating gendered standards of behavior were more likely to condone intimate partner violence in a greater number of vignettes (adjusted odds ratios [AORs] ranged from 3.87 to 5.74, with all p < 0.001), while participants assigned the survey variant that depicted the wife as unintentionally violating these standards were less likely to condone intimate partner violence (AORs ranged from 0.29 to 0.70, with p-values ranging from <0.001 to 0.07). The analysis of perceived norms displayed similar patterns, but the effects were slightly smaller in magnitude: participants assigned to the “intentional” survey variant were more likely to perceive intimate partner violence as normative (AORs ranged from 2.05 to 3.51, with all p < 0.001), while participants assigned to the “unintentional” survey variant were less likely to perceive intimate partner violence as normative (AORs ranged from 0.49 to 0.65, with p-values ranging from <0.001 to 0.14). The primary limitations of this study are that our assessments of personal beliefs and perceived norms could have been measured with error and that our findings may not generalize beyond rural Uganda.

Conclusions

Contextual information about the circumstances under which women in hypothetical vignettes were perceived to violate gendered standards of behavior had a significant influence on the extent to which study participants endorsed the acceptability of intimate partner violence. Researchers aiming to assess personal beliefs or perceived norms about intimate partner violence should attempt to eliminate, as much as possible, ambiguities in vignettes and questions administered to study participants.

Trial registration

ClinicalTrials.gov NCT02202824.

Three amazing nature areas shortlisted for World Heritage status

New Scientist - Ma, 23/05/2017 - 19:50
Newly proposed world heritage sites in Argentina, China and West Africa could safeguard threatened and endemic species such as elephants and snow leopards

Trump’s 2018 budget slashes funding from healthcare and science

New Scientist - Ma, 23/05/2017 - 19:05
Medicaid is slated to lose billions of dollars in funding, as are many medical, humanitarian and scientific organisations

Bioelectric tweak makes flatworms grow a head instead of a tail

New Scientist - Ma, 23/05/2017 - 19:00
Flatworms regenerate lost body parts, but change the current in their cells and they can regrow the wrong thing, hinting at electricity’s role in body plans

Tangoing pairs of hungry supermassive black holes grow in number

New Scientist - Ma, 23/05/2017 - 18:06
The discovery of more of these deadly duos through a fresh data-sifting technique raises the hope that their secret recipe might soon be unlocked

Artificial Venus flytrap grabs things over 100 times its weight

New Scientist - Ma, 23/05/2017 - 18:00
Less than a centimetre in size, the soft robotic device can detect items based on how they reflect light and grasp them with impressive force

Unimpeachable logic says Trump shouldn’t quit Paris climate pact

New Scientist - Ma, 23/05/2017 - 17:08
President Donald Trump should keep the US in the Paris Agreement on climate and embrace it as a great deal for his nation's economy, says Owen Gaffney

A classic quantum test could reveal the limits of the human mind

New Scientist - Ma, 23/05/2017 - 15:00
Using human consciousness as the trigger in a test of ‘spooky action at a distance’ could tell us whether mind is made of different stuff than matter

DeepMind’s AI beats world’s best Go player in latest face-off

New Scientist - Ma, 23/05/2017 - 14:02
The Go-playing artificial intelligence from DeepMind defeated Ke Jie in the first of three matches taking place this week in Wuzhen, China

Unprecedented cholera outbreak tears through war-torn Yemen

New Scientist - Ma, 23/05/2017 - 13:24
Cholera has killed 332 people and left more than 32,000 ill over the past four weeks, spreading faster than any previous known outbreak in the country

Diabetes drug may work by changing gut bacteria makeup

New Scientist - Ma, 23/05/2017 - 12:45
Metformin dramatically shifts the gut microbiome – and bacteria seem to play a key role in controlling blood sugar levels

Astronomers scramble as ‘alien megastructure’ star dims again

New Scientist - Ma, 23/05/2017 - 12:30
Tabby’s star’s weird behaviour has been blamed on everything from asteroids to aliens. Now astronomers are racing to watch its dimming in action

Weird energy beam seems to travel five times the speed of light

New Scientist - Ma, 23/05/2017 - 08:30
The galaxy M87 emits a jet of plasma that looks like it’s breaking the cosmic speed limit – here’s how it manages the trick

EU nations set to wipe out forests and not account for emissions

New Scientist - Ma, 23/05/2017 - 02:01
The drive for biofuels that international treaties wrongly consider to be emissions-free is driving plans to boost tree harvests in Europe, forgetting about associated emissions

Mouse sperm sent into space produces healthy IVF babies

New Scientist - Lu, 22/05/2017 - 22:00
The first experiment to test how space travel could affect mammals’ reproduction shows that pregnancy can smooth over DNA damage from cosmic radiation

Our common ancestor with chimps may be from Europe, not Africa

New Scientist - Lu, 22/05/2017 - 21:00
The last common ancestor of chimps and humans was an eastern European, claims team that analysed fossils of a 7-million-year-old ape from Bulgaria and Greece
Condividi contenuti