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Category Archives: Mind Building
Hurricane Harvey samples saddled with antibiotic-resistant genes
Rice University scientists have released the first results of extensive water sampling in Houston after the epic flooding caused by Hurricane Harvey. They found widespread contamination by E. coli, likely the result of overflow from flooded wastewater treatment plants.
The microbial survey showed high levels of E. coli, a fecal indicator organism, trapped in homes that still contained stagnant water weeks after the storm, as well as high levels of key genes that indicate antibiotic resistance.
The study led by Rice environmental engineer Lauren Stadler appears in the American Chemical Society journal Environmental Science & Technology Letters. A pair of National Science Foundation RAPID grants helped the team collect and analyze samples.
Rice environmental engineers Stadler, Qilin Li and Pedro Alvarez and their students were on the front lines, even before Harvey subsided, to take samples from floodwaters near the overflowing Brays and Buffalo bayous, in public spaces and inside and outside residential homes to compare their microbial content. Samples of stagnant water were taken from homes that had been closed off for more than a week, while others were taken from homes that had floodwater flowing through them.
Early samples from each location carried elevated levels of E. coli. But most striking was the fact that sampled water and, later, sediment showed abundant levels of two indicator genes, sul1 and intI1, that mark the presence of antibiotic-resistant bacteria, even weeks after the flood. In particular, samples from floodwaters inside closed homes showed concentrations of sul1 were 250 times greater and intI1 60 times greater in than in bayou samples.
“Sul1 is a gene that confers resistance to sulfonamide antibiotics,” said Stadler, an assistant professor of civil and environmental engineering. “IntI1 is not an antibiotic-resistant gene, but an integron-integrase gene that encodes for a system of gene capture and dissemination and can lead to the spread of antibiotic-resistant genes among bacteria. A lot of antibiotic-resistant genes are on or associated with mobile genetic elements like plasmids that can be shared among bacteria.
“We target intI1 because integrons are often found on mobile genetic elements and indicative of the genetic mobility of a gene,” she said. “They are also often associated with antibiotic resistance, and the abundance of these genes gives us a sense of the potential for horizontal gene transfer among bacteria.
“That matters because while we see these genes in environmental bacteria all the time, we really worry when pathogenic bacteria acquire resistant genes from environmental bacteria,” Stadler said. “That’s when there’s an issue — when there’s an antibiotic-resistant pathogen. If you’re exposed to one of those, that’s when you see infections that are really hard to treat.”
The immediate takeaway from the study, she said, is that people should take extra care to avoid direct contact with stagnant floodwaters, especially in flooded homes with niches for pathogens to grow.
“Wear protective gear, and don’t go in at all if you’re immunocompromised or have open wounds,” she said.
Stadler’s research group is using the experience gained during Harvey to advance development of tools to measure horizontal gene transfer as it takes place in the environment.
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Archeological plant remains point to southwest Amazonia as crop domestication center
The remains of domesticated crop plants at an archaeological site in southwest Amazonia supports the idea that this was an important region in the early history of crop cultivation, according to a study published July 25, 2018 in the open-access journal PLOS ONE by Jennifer Watling from the Museum of Archaeology and Ethnology at the University of São Paulo, Brazil and colleagues.
Genetic analysis of plant species has long pointed to the lowlands of southwest Amazonia as a key region in the early history of plant domestication in the Americas, but systematic archaeological evidence to support this has been rare. The new evidence comes from recently-exposed layers of the Teotonio archaeological site, which has been described by researchers as a “microcosm of human occupation of the Upper Madeira [River]” because it preserves a nearly continuous record of human cultures going back approximately 9,000 years.
In this study, Watling and colleagues analyzed the remains of seeds, phytoliths, and other plant materials in the most ancient soils of the site as well as on artefacts used for processing food. They found some of the earliest evidence of cultivated manioc, a crop which geneticists say was domesticated here over 8,000 years ago, as well as squash, beans, and perhaps calathea, and important tree crops such as palms and Brazil nut. They also saw evidence of disturbed forest and a soil type called “Anthropogenic Dark Earths” which both result from human alteration of local environments.
These findings suggest that the people of this region transitioned from early hunter-gatherer lifestyles to cultivating crops before 6,000 years ago, much earlier than previously thought. Along with plant domestication also came the familiar human habit of landscape modification, suggesting that human impact on Amazonian forests in this region goes back many thousands of years. Altogether, these results point to the Upper Madeira as a key locality to explore the earliest days of crop domestication in the New World.
Watling notes: “This discovery at the Teotonio waterfall in Southest Amazonia is some of the oldest evidence for plant cultivation in lowland South America, confirming genetic evidence.”
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Leggy lizards don’t survive the storm
Nobody knows exactly what happens at the eye of the storm.
But biologists at Washington University in St. Louis have published a first-of-its-kind look at the physical characteristics of lizards that seem to make the difference between life and death in a hurricane, as reported in the July 25 issue of the journal Nature.
Hint: long, strong back legs do not help like you think they might.
The hyperactive 2017 hurricane season was one of the worst ever experienced in the Atlantic Ocean region. Damage from totals for the hurricane season topped $282 billion — the costliest on record. Hurricane Harvey hit in mid-August 2017, followed just a few weeks later by Hurricane Irma and Hurricane Maria in September. Each of these storms had winds in excess of 125 mph, with Irma up to 170 mph.
For humans, the devastation to homes and businesses was extreme. For tropical anole lizards living on the more remote cays of Turks and Caicos, there was only the ones who survived — and the ones who didn’t.
And that’s where the researchers came in, using data serendipitously collected just before the storms hit, and again weeks afterward, to demonstrate for the first time the effects of hurricane-induced natural selection.
“Hurricanes are in the news, and it seems that they’re becoming more destructive,” said Jonathan Losos, the William H. Danforth Distinguished Professor at Washington University and professor of biology in Arts & Sciences. “Something like this has never been documented before because it’s so difficult. The timing had to be just right.”
Last eyes on the lizards
Colin Donihue is a postdoctoral fellow at Harvard University who is conducting research with Losos, who was previously at Harvard. Last September, Donihue was just wrapping up his measurements of endemic Turks and Caicos anole, Anolis scriptus, as a baseline for a long-term invasive species eradication project when Hurricane Irma started to brew.
The sky was still bright blue, but the weather forecasters were getting anxious. As Donihue quickly gathered his stuff and headed for the airport, his local cab driver was more skeptical: This storm would blow over, he told Donihue, just like others had done in the past.
Four days later, Hurricane Irma made landfall on Sept. 8, 2017. Donihue read the news of its devastation from his apartment in Boston. He realized his lizard data might have value outside of its original intent.
Donihue had the last eyes on the population before an unthinkable natural disaster. Now, it was time to determine if the storms had been a “selective event” — an event with the power to change the course of life not just for the lizards that had weathered them, but potentially for the generations that followed.
So Donihue started making calls. The Turks and Caicos government was in recovery mode; clean water, electricity and shelter were priorities, and basic phone and Internet services were still not available across the islands. But Donihue had made good connections during his recent trip, and one government scientist in particular was sympathetic to his pleas. A new set of biological permits was granted, and Donihue and study co-author Anthony Herrel of the Paris Museum were back on a plane.
Before and after the storm
Back on the experimental islands, it was a mess. Trees were down and tree-limbs strewn about, making it difficult to walk in some places. But there were signs of life.
“Heading back to Pine Cay, we weren’t sure what we’d find, but when we got to the field and saw a few lizards running around, we were eager to get catching and start measuring,” said Donihue, who holds a National Science Foundation (NSF)-funded fellowship that will bring him to Washington University in the winter of 2019.
“We walked exactly the same transects we had the last time,” Donihue said. “There were definitely fewer lizards. We had to work harder to catch our sample size.”
The team spent two days collecting just shy of 100 lizards on two separate islands, then measured their forelimbs, hindlimbs and core body lengths, and took pictures of their toe pads.
The vital statistics of the survivors could be compared with the measurements of the general lizard population that had been collected before the storm.
“The prediction was that if we saw any changes, they would be changes in the features that help lizards hold on — they would be related to clinging ability,” Donihue said. “For example, the sticky toe pads on their fingers and toes, maybe they would be larger.”
Comparing lizards collected before and after the storm, the researchers found that the survivor populations on both islands had larger toe pads on both their forelimbs and hindlimbs.
The survivors had proportionately longer fore legs than the initial/pre-hurricane population, while the long bones in between their hips and knees on their back legs (their femurs) were shorter. The survivor population had smaller bodies, too. The observations were statistically significant and consistent at both island sites.
Natural selection favors certain characteristics
Hurricanes bring death and destruction to those in their paths. There are well-documented recent examples of hurricanes killing off large numbers of individuals from many species as diverse as plants, sea sponges, insects, birds and monkeys.
“With regard to evolution, the question is whether hurricanes cause selective mortality: do individuals with certain traits survive better than individuals with different traits? The alternative possibility — that devastation is so massive that mortality is indiscriminate, not favoring some individuals over others — is certainly possible,” Losos said.
The results of this study — that the island populations of lizards both changed significantly, and in the same way from before the hurricanes to after — suggest that natural selection favored individuals with certain characteristics.
Of course, as the authors point out, there are other possibilities.
“Perhaps the hurricane blew in lizards with bigger toepads and shorter hindlegs from another island. Or perhaps the act of clinging to the branches in high winds actually caused their forelegs to get longer,” Losos said. “We can’t rule these possibilities out because this study was the result of serendipity, rather than specifically being designed to test the effect of hurricanes.
“Still, hurricane-induced natural selection seems like the best explanation for these findings,” Losos said.
Behavioral piece is still unknown
The missing piece of the story is still a behavioral one. Researchers don’t know what lizards actually do in the middle of a hurricane. Do they abandon their typical tree perches and go to the ground? Or do they try to seek cover in notches or crevices within the trees? Or do they just hang on?
A pilot study exploring wind threshold provides some insight into this aspect of the lizard decision-making process.
When the researchers exposed lizards from the survivor population to hurricane-force winds, the lizards almost uniformly swiveled around their perches to the side opposite from the wind source — and just held on tight. As wind speeds increased, they lost hold with their hindlimbs first, and were left hanging by their forelimbs.
It appears that lizards are built to cling, but because of their stance on the perch, their big hindlimbs make them vulnerable to getting pushed off by high winds. This could explain the pattern that survivor lizards have longer forelimbs and shorter hindlimbs after a hurricane, the researchers speculate.
A future with bigger, and more frequent storms
Understanding how storms select for species survival is an important area of future study, worthy of a dedicated study design.
“We know that hurricanes are getting more frequent, and we know that they’re getting more strong,” Donihue said. “So, setting up a network of sites that are actually set up to investigate the question of how hurricanes are changing the evolutionary trajectory of species I think could be really useful.”
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Nurses’ pay: Union chief apologises over mix-up
Nurses have complained on social media their pay went up by much less than their union had promised.
Health24.com | 30 years in prison for not disclosing HIV status
Amsterdam – Kerry Thomas is in prison in the USA, serving a 30-year sentence for having sex twice without disclosing to his partner that he was HIV positive.
Although Thomas used condoms, had an undetectable viral load and did not infect his partner, he was given two 15-year sentences to run consecutively. He has already served 10 years of his sentence.
Criminalising the transmission of HIV
Joining delegates to the International AIDS Conference by phone from his Idaho prison, Thomas said that while he regretted not disclosing his HIV status, “I worked with my doctor to protect my partner.”
“It is high time to look at the growing move to criminalise the transmission of HIV, which is often based on a misunderstanding of how HIV is and isn’t transmitted,” said Professor Linda-Gail Bekker, president of the International AIDS Society.
Twenty top scientists, including Nobel Laureate Francoise Barre-Sinoussi, released a consensus statement at the conference yesterday after reviewing the best available scientific evidence relating to HIV transmission and concluded:
- It is not possible for an HIV positive person to transmit the virus in their saliva while kissing, biting or spitting.
- The risk of HIV transmission from a single act of unprotected sex is very low, and there is no possibility of transmission during either vaginal or anal sex if the HIV-positive partner has an undetectable viral load.
- It is not possible to establish proof beyond reasonable doubt that one person has infected another, even with the most advanced phylogenetic scientific tools.
Some 68 countries have laws that criminalise HIV non-disclosure, exposure or transmission, while 33 others have applied similar laws in specific cases.
Convicted for breastfeeding
Thousands of people living with HIV have been prosecuted, most of who did not actually pass on the virus. Most prosecutions have taken place in the USA, Belarus, Ukraine, Russia and Zimbabwe.
Sarai-Chisala Tempelhoff of the Women’s Lawyers Association of Malawi said that an HIV positive woman in her country had been convicted for breastfeeding her baby.
“This prosecution for breastfeeding was not informed by science, and the magistrate demonstrated stigma not science,” said Templehoff.
Edwin Bernard, global co-ordinator of the Global HIV Justice Network, said there was an urgent need to train and educate judges and magistrates, many of whom operated on the basis of prejudice not fact.
Impact of prosecution
South Africa has not adopted an HIV-specific criminal law, although there was a push to do so in 1999.
“I think we can give credit to our Members of Parliament for that,” said Judge Edwin Cameron, who is attending the Aids conference.
“There was a move in 1999 to make HIV transmission a specific crime, but this was ultimately rejected by our politicians, although HIV status can be considered an aggravation of sentence in rape,” said Cameron.
“The scientific community has spoken and now the criminal justice sytem, law and policymakers must also consider the impact of prosecutions on the human rights of people living with HIV,” said Michaela Clayton of AIDS and Rights Alliance for Southern Africa (ARASA). – Health-e News
Image credit: Kerry Cullinan
Boys more ‘cliquey’ than girls
Boys are more likely to keep the same group of friends, research suggests.
Health24.com | The complete guide to staying fit in your 20s, 30s, 40s and 50s
There’s no secret to living a long and healthy life. You can be just as fit in your 50s as you were in your 20s. All you need is time and exercise. Use this guide to become your fittest, strongest self – no matter how old you are.
Read more: Fitness secrets from our 2017 MH cover guys
Your 20s
The breakdown
This is the time to find out what exercise or sport suits you best. You’re in peak physical shape, so trying out new things will never be easier. Your muscle mass, bone density and aerobic capacity are all in optimal condition.
“Men should take advantage of this power by incorporating resistance training with explosive and plyometric exercises to become fit and strong,” advises David Leith, biokineticist at the Sports Science Institute of South Africa.
Your play: Train smart
The precise type of training you should do will differ depending on your training goals. To remain strong and fit, follow this formula:
- Incorporate regular resistance training (at least three times a week, with emphasis placed on functional moves which allow your joints full range of motion).
- Easy aerobic training two to three times a week.
- HIIT once to twice per week.
- Include basic injury-prevention “stability” or mobility exercises. These can be performed as individual sessions like yoga or Pilates, or use them as a warm-up or cool-down for your main workout.
Don’t allow your youthful enthusiasm to get the better of you. Progressively increasing your training is crucial to preventing injuries. Leith cautions against overtraining. “This often occurs in people who are starting a new sport, especially running, leading to recurring niggles and more serious injuries.”
Read more: Use this workout plan to master the Superman push-up in under a month
Your 30s
The breakdown
Life becomes more complicated for you in your 30s. You’ve started a family and increased your responsibilities at work. Not only is finding time to train difficult but training itself becomes harder. Your metabolism starts slowing down and gaining body fat happens more quickly than before. Leith cautions men at this age against falling out of their training habits. “De-training occurs rapidly; and starting again is tough, both mentally and physically.” He recommends you train in a more time-efficient manner to ensure you stay fit.
Your play: Plan ahead
Your increased commitments mean you might find yourself with less time to train. Leith advises you plan your sessions beforehand, so that when you arrive you’re ready to spring into action.
Focusing on shorter sessions will be more rewarding and feasible – ensuring adequate rest time between sessions.
He recommends you reassess your training load to make sure it’s still feasible. If you’re short on time, he advises you avoid splitting your sessions into upper versus lower body. Instead, perform more full-body workouts, and combine strength and endurance into a single session.
Include quick spinning sessions into your training. Alternatively, go for short, fast runs.
Read more: Cristiano Ronaldo’s Guide to a champion’s six-pack
Your 40s
The breakdown
Your experience from the previous two decades will serve you well as you continue training at this age. In your 40s you’re at risk of developing chronic diseases, such as diabetes and high blood pressure. Along with a healthy diet and adequate sleep, exercise becomes a form of preventative medicine to stave off these diseases. Leith says maintaining regular resistance training and appropriate loading activities, such as running and hiking, is essential to prevent sarcopenia (age-related decline in muscle mass) and osteoporosis (reduced bone-mineral density).
Your play: Focus on mobility
In your 20s, you could skip flexibility and stability exercises without suffering the consequences; now, that decision could cost you your range of motion.
Long days of sitting behind your desk often result in lower back pain and restricted movement, making mobility exercises essential. “While maintaining other resistance training and cardiovascular training, it’s important to perform regular stability and activation work to promote sound postural alignment and joint mobility,” says Leith.
But mobility exercises aren’t just good for your joints; they’ll allow you to perform your lifts better. Leith recommends you include them in your warm-up before your resistance-training sessions.
For men concentrating primarily on gym training, Leith suggests performing more full-body sessions with compound lifts. These will provide the greatest benefit towards your training goals.
If you’ve returned to training after skipping the gym in your 30s, Leith recommends you increase your weight training progressively, just as someone in their 20s would who was new to training.
Read more: Rugby player Stefan Terblanche shares his advice on building monster muscle and fitness
Your 50s
The breakdown
You’ve reached your golden age. But this is not the time to hang up your gloves. Instead, adjust your training to match what your body can do. With dwindling muscle mass and bone density, you’re no longer exercising to look good; you’re exercising to prevent major injuries (and to stay alive). Your joints are your biggest issue at this age. Prevent falls and fractures by incorporating balance and proprioception training into your routine.
Your play: Quality over quantity
At this age, the quality of your training is more beneficial to you. This means performing exercises with sound form and through full range of motion. “Be careful not to injure yourself, and don’t rush your training,” advises Leith. He recommends maintaining a proper warm-up with dynamic stretches, and cool-down with static stretches.
Regular resistance training is your friend at this age. Include at least two sessions a week into your routine to offset the decline in muscle mass and bone density. Focus on functional movement patterns that make performing daily activities easier.
Modify your exercises if you’re having trouble with your joints – use less weight or incorporate aqua training into your programme.
Aim to maintain regular cardiovascular training, about three to four times a week, for 30 minutes a session. Keep these sessions interesting by heading outdoors for a hike for one of these sessions.
This article was originally published onwww.mh.co.za
Image credit: iStock
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Health24.com | New ARV not for women wanting to fall pregnant, WHO warns
Amsterdam – Dolutegravir, the new wonder antiretroviral drug, should not be given to women who want to get pregnant, the World Health Organisation (WHO) warned this week.
South Africa stopped its planned switch to dolutegravir in June after a study in Botswana found that four women out of 596 pregnant women on the drug had given birth to babies with neural tube defects.
But Dr Rebecca Zash, from the Botswana-Harvard AIDS Institute Partnership, told the International AIDS Conference that it seemed that only babies born to women who had been taking dolutegravir at conception were at risk.
“Dolutegravir was just as safe as efavirenz [the ARV it replaced] for women who started on dolutegravir during pregnancy,” said Zash, but said that more information about the drug was needed.
“The study was small. We have since had another 170 births with no defects, but we need more data,” said Zash.
Neural tube defects happen in the first 28 days after conception.
Dolutegravir is easily tolerated, suppresses the virus faster than many other ARVs and the virus does not develop resistance to it fast.
Botwana switched to dolutegravir in June 2016, and South Africa was due to follow suit this June. A modeling study of a dolutegravir-based treatment regimen predicted that it could prevent over 25,000 deaths among women and 5,000 child infections compared to efavirenz-based ART over five years in South Africa.
Civil society delegates staged a protest at the conference demanding that women be given the right to choose between dolutegravir and efavirenz.
However, scientists said that women on dolutegravir must be on contraception until safety concerns are addressed.
– Health-e
Health24.com | Southern Africa finally getting to grips with HIV
Amsterdam – Over three-quarters of HIV positive Namibians have such low levels of the virus in their bodies that they are “virally suppressed”, making Namibia the first country in Africa to meet this global target.
Namibian Health Minister Bernard Haufiku told the International AIDS Conference that the results were based on a household survey of 23 000 Namibians.
‘We are on track’
The global target set by the Joint UN Agency on AIDS (UNAIDS) is for 73% of people on antiretroviral treatment to be virally suppressed by 2020, but Namibia had already exceeded this target three years early, with 77% of people virally suppressed.
“This means we are on track to control the HIV epidemic, because treatment is also prevention,” said Haufiku, referring to the fact that people with viral suppression are no longer infectious and highly unlikely to pass HIV to others.
Namibia has managed to reduce its rate of new HIV infections by 50% over the past three years.
Meanwhile, eSwatini (Swaziland) has managed to reduce its rate of new HIV infections by 44% since 2011 by offering all people with HIV immediate access to ARVs – an approach called “universal test and treat”. In the past, people with HIV had to wait for their CD4 count to drop before they were allowed to get ARVs.
“This is the first time that treatment as prevention is proven to work, not just in a research setting but on a large scale in real life,” said Dr Velephi Okello, from eSwatini’s health ministry.
Turning back the epidemic in Africa
South Africa has also reduced its rates of new infections by 44%, according to the HSRC Household study released last week.
Meanwhile, a Botswana study reported that a package of interventions, including expanded HIV testing, earlier treatment and male circumcision, led to a 30% cut in new HIV infections over 30 months.
“It is great to get some good news from southern Africa, the region where I am from,” said Professor Linda-Gail Bekker, President of the International AIDS Society and International Chair of AIDS 2018.
“The data presented today underscore both the urgent need and the opportunity to invest in expanded HIV prevention and treatment programmes that can turn back the epidemic in Africa.”
However, Unicef warned that 9.6 million young people aged 15 to 24 years will be newly infected with HIV in sub-Saharan Africa between 2017 and 2050.
“About two-thirds of these will be girls or young women,” said Aleya Khalifa of Unicef.
“Young people in sub-Saharan Africa will require better access to HIV prevention, sexual and reproductive health, and targeted testing services.” – Health-e News.
