Tag Archives: wall

Researchers map the molecular structure of wood in bid to make it more resilient

The molecular structure of wood is what gives the material its strength and flexibility — and new research is uncovering its secrets.

New research from the Cambridge University’s Department of Biochemistry aims to understand what makes wood strong so that we know how to make it even stronger. The team hopes that their findings can guide future forestry breeding programs towards producing stronger wood than ever before — and support the renewed interest wood is receiving as an alternative building material to steel and concrete.

Wooden it be nice?

“It is the molecular architecture of wood that determines its strength, but until now we didn’t know the precise molecular arrangement of cylindrical structures called macrofibrils in the wood cells” says Dr Jan Lyczakowski, the paper’s first author from Cambridge University’s Department of Biochemistry.

“This new technique has allowed us to see the composition of the macrofibrils, and how the molecular arrangement differs between plants, and it helps us understand how this might impact on wood density and strength.”

While there is a will, we’re still lacking a way — wood simply has inferior mechanical properties to the materials we want to replace. Its main limitation comes in regards to the load bearing superstructures of major buildings. Here, wood simply can’t perform the task: it bends, and it breaks.

However, the team believes that the fault doesn’t lie with the material itself, but rather in our limited understanding of the precise structure of wood cells.

Wood is strong because each cell that makes it up is surrounded by a thick, hardy wall. This ‘secondary wall’ is constructed out of a mix of polymers, cellulose, hemicellulose, further reinforced with lignin. The team, which also included members from Cambridge University’s Sainsbury Laboratory (SLCU) used low-temperature scanning electron microscopy (cryo-SEM) to look at the nanoscale architecture of living tree cell walls. They were looking at the microscopic details of macrofibrils in the secondary wall, which are long molecules 1000 times narrower than the width of a human hair.

They collected samples from spruce, gingko, and poplar trees in the Cambridge University Botanic Garden. Each sample was flash-frozen to keep the cells in a life-like state, and then coated in a platinum film three nanometers thick to be viewable under the electron microscope.

“Our cryo-SEM is a significant advance over previously used techniques and has allowed us to image hydrated wood cells for the first time,” said Dr Raymond Wightman, Microscopy Core Facility Manager at SLCU.

“It has revealed that there are macrofibril structures with a diameter exceeding 10 nanometres in both softwood and hardwood species, and confirmed they are common across all trees studied.”

The researchers also looked at the secondary cell walls of thale cress (Arabidopsis thaliana), a plant that is used as a model organism in genetics and molecular biology research — the plant also showed the same macrofibril structures. Using several of these plants, each showing different mutations relating to the secondary cell wall and its formation, the team was also able to identify the role of specific molecules in the development of the macrofibrils. Based on their results, the team recommends thale cress as a suitable model for future forestry breeding programmes.

“Visualising the molecular architecture of wood allows us to investigate how changing the arrangement of certain polymers within it might alter its strength,” said Professor Paul Dupree, a co-author of the study in Cambridge’s Department of Biochemistry.

“Understanding how the components of wood come together to make super strong structures is important for understanding both how plants mature, and for new materials design.”

“If we can increase the strength of wood, we may start seeing more major constructions moving away from steel and concrete to timber.”

The paper “Structural Imaging of Native Cryo-Preserved Secondary Cell Walls Reveals the Presence of Macrofibrils and Their Formation Requires Normal Cellulose, Lignin and Xylan Biosynthesis” has been published in the journal Frontiers in Plant Science.

Two-thousand-year-old ‘Great Wall of Siberia’ discovered by archaeologists

The findings are comparable to Hadrian’s Wall, which separated Roman England from the ‘wild’ Scotland.

Views around Souzga village; the Great Wall of China and Hadrian Wall. Pictures: The Siberian Times.

The big wall club

Walls seem to be a hot topic these days, though their purpose hasn’t really changed much across the centuries. Their straightforward purpose is to keep people out. People built walls around their huts, around their churches, their towns, and even their countries. Back then, it wasn’t so much about keeping immigrants out, as it was about defending from invaders. The Romans built a massive wall in northern England. Hadrian’s Wall has inspired countless myths and legends, including the great Wall from Game of Thrones. But for the Romans, the wall was a very practical investment which served to protect the edge of their empire from Scottish pillaging raids and invasions.

Even Hadrian’s Wall pales in comparison to the Great Wall of China. Several walls were being built as early as the 7th century BC in China, for defense and to serve as border control. Those bits and pieces were maintained, enhanced, and ultimately connected. The Great Wall reached its greatest form during the Ming Dynasty (1368–1644).

Well, the select club of epic walls might get another addition: the Siberia Wall in the Altai Mountains.

Ramparts and walls

Today, the wall system is barely visible, but it must have been truly humbling in its time. Professor Andrey Borodovsky, an archaeologist working in the Altai Mountains in eastern Russia, says that it measured eight meters high, and had a width of ten meters.

‘To the east of these walls is a fairly wide passage, which is limited at the mountainside by another series of walls, oriented west-east across the Katun valley,’ he said.

Siberian scientists study the Altai walls, concealed under thick layers of turf. Picture: Andrey Borodovsky.

Just on a single hillside, he found nine adjacent walls, connected in a rampart system. At the moment, it’s unclear who built the system, though Borodovsky believes that based on their structure, the walls were more a Trump-style border control than a Roman defense system.

‘These walls were clearly made to cut off crowds of people, and make them go through a narrow passage in the direction chosen by the creators of the (construction).’

Location of the Altai Walls. Picture: Andrey Borodovsky.

The existence of archaeological remnants in the area was known for quite a while. However, much of the wall system was destroyed by the construction of the Chuya highway in tsarist times. Later on, Stalin continued work on the highways using prison labor — and destroyed even more swaths of archaeological walls. The expansion of the modern-day village Souzga village also took its toll, leaving only stumps of the walls’ former glory. But even so, what’s left is impressive.

Seeing the unseen

The problem is that the entire system is covered by turf, to the point where it’s barely visible to the naked eye. Sattelite imagery also doesn’t help that much, so Borodovsky used geophysical techniques — especially a method called resistivity.

The subsurface location of the walls, as interpreted by the Russian archaeologist. Location of the Altai walls, and data from geophysical analysis. Picture: Andrey Borodovsky.

In Electrical Resistivity Tomography (ERT) current is pumped into the ground through electrodes, and measured on other electrodes. Based on this measurement, characteristics of the underground can be assessed, and man-made material can be separated from natural soil and rocks (to some extent). He also used seismic methods, where an earthquake-like wave is created, and information can be derived based on its reflection captured at a sensor.

‘Geophysics has clearly confirmed that the Souzga walls were artificially created,’ he told The Siberian Times.

Still, the age of the walls is still open for discussion. Borodovsky says he doesn’t know the exact age of the walls yet, but he estimates it around the first millennium BC.

‘It is not very easy to determine the age of such constructions, when exactly were they created, but I believe it was around the first millennium BC – the beginning of new era. That is Iron Age or even Bronze Age, but more likely – Iron Age.’

‘I’m basing this on the fact that it was the time when such constructions are created all over the world, for example the famous Hadrian’s Wall also fits into this trend.’

The Altai Walls were even more impressive than Hadrian’s Wall in northern England, which still survives today. Image credits: Steven Fruitsmaak.

The problem is that what little has been found on the surface has been dated to medieval times. But Borodovsky believes the medieval people only built on top of the ancient walls and didn’t create them from scratch. He says that medieval people wouldn’t have had the interest or the money for such a massive project.

‘I still believe that in Middle Ages there was not a big enough community here which could afford to build such a formidable construction. Besides, there also was no need for such a construction because in Middle Ages there were a lot of small, scattered communities here.’

There’s also a matter of historical coherence which supports his assumption. Many important Eurasian defense lines date from the beginning of the first millennium BC up to a few hundred years in the Current Era. Borodovsky explains:

‘Such a fortification process was due to a number of factors. First, the appearance of significant human resources in this era, thanks to the potential of an integrated manufacturing economy. Secondly, the aggravation of military conflicts and a significant increase in their scale. Thirdly, the formation of large state and proto-state entities, which had economic, cultural and political boundaries and these boundaries … to separate their world from aliens.’

It also remains to be seen what culture created this magnificent defense line. Among the suspects are ancient people such as the Pazyryk culture, a Scythian Iron Age culture, who buried mummies in long barrows (or kurgans) and seemed to have a flourishing civilization from the 6th to 3rd centuries BC.

Believe it or not, there are actually wild jaguars living in the United States. These handful of individuals will become isolated from the rest of the population south of the border if Trump's wall will get erected. Credit: Wikimedia Commons.

Trump’s border wall could threaten 111 endangered species

Believe it or not, there are actually wild jaguars living in the United States. These handful of individuals will become isolated from the rest of the population south of the border if Trump's wall will get erected. Credit: Wikimedia Commons.

Believe it or not, there are actually wild jaguars living in the United States. These handful of individuals will become isolated from the rest of the population south of the border if Trump’s wall will get erected. Credit: Wikimedia Commons.

Deep down, we all hoped President Trump’s ‘big, beautiful wall’ was just a ruse — an attempt to incite American sentiment and shift votes into his rather small hands. But by all accounts, the man seems to be serious about it. If left to his devices, it seems quite likely that a 1,300-mile-long concrete wall will be erected along the US-Mexico border. Even if it’s as big and grandiose as Trump boasts, research suggests it won’t stop the flow of illegal immigrants into the country (on the contrary) or drugs. But if there’s one thing this border wall will be good at is stopping animals from flowing in and out of Central America northwards, and vice-versa.

According to the US Fish & Wildlife Service (FWS) “111 endangered species, 108 species of migratory bird, four wildlife refuges and fish hatcheries, and an unknown number of protected wetlands” could be threatened by Trump’s border wall which genetically isolates populations and blocks seasonal migration. These include ocelots, bears, Bighorn sheep or the last wild jaguars in the US. Even the US national bird, the Bald eagle, will be affected by this wall which is set to disrupt its habitat.

The border with Mexico is around 3,100 km (1,900 miles) long, and much of it is already fenced off. Trump’s plan is to erect a 1,300 miles long, 40-feet-high wall which contains 19 million tons of concrete and could cost in excess of $25 billion. Along with natural barriers, this ‘Great Wall of America’ should keep illegal immigrants and drugs flowing into the country, although we previously reported that over the years as the United States militarized its borders, more and more undocumented immigrants stayed into the country — simply because they got stuck there.  For every million-dollar increase in budget, the odds a migrant would return home to Mexico in any given year dropped by 89 percent.

The FWS’ report is “for informational purposes only and should not be used for official planning purposes”. Outside reports section 7 of the Endangered Species Act clearly stipulates any construction project  “permitted, funded, or licensed by any federal agency” has to be reviewed by the FWS but the Trump Administration has made no such request. 

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Most of these animals are negatively impacted by the wall because it isolates cross-border populations. If a solid, concrete wall is erected, it’s likely inbreeding will increase and genetic diversity will decrease, making species more vulnerable. The few jaguars that roam in Arizona and New Mexico will probably slowly but surely get wiped out from the United States as these become stranded, unable to mate with more numerous populations south of the border. Even the bald eagle or manatees, flying and marine species which at first glance shouldn’t be affected, will be threatened by the wall which encroaches on their critical habitat.

As The Ecologist reports, a 2011 study which assessed bioconservation at the US-Mexico border found barriers significantly impede animal migrations within this ecologically sensitive region. In other words, the fences already in place at the border put more than 50 species at risk. The authors of the study cautioned at the time that “New barriers along the border would increase the number of species at risk, especially in the three identified regions, which should be prioritized for mitigation of the impacts of current barriers.”

All of these reports likely fall on deaf ears, though. There seems to be little to any consideration given to official reports, figures, data, or experts for that matter. Trump’s ‘educated guesses’ as to how much this planned border wall would cost — he’s been quoted as saying around $5 billion when the real cost would be at least five times that, and far more if you account maintenance over the coming decades — is very telling of how much thought goes into the Presidential Administration’s executive orders.