Monthly Archives: January 2020

Cell Biology

Aberdeenshire schools urged to get creative and light the north – Buchan Observer

Schools and community youth groups are being asked to get involved with a creative north-east sculpture and education programme.

The leading cancer support and wellbeing charity, CLAN Cancer Support, is looking for young people to get involved with the Little Lights Education programme, which will run alongside the Light the North lighthouse trail.

The trail will take place in Autumn 2020 and will see 8 ft high decorated lighthouses and mini lighthouse sculptures across Aberdeen and Aberdeenshire, Moray, Orkney and Shetland.

The Little Lights Education Programme links to the Curriculum for Excellence with all participating schools and community groups being provided with a creative learning resource pack.

The pack contains a programme of study designed to complement teaching of numerous subjects including the history and development of lighthouses, a link to the sea including renewables and wider energy sector, maritime, cell biology, physical health and emotional wellbeing with a focus on the development of personal resilience.

Iona Mitchell, CLANs head of cancer support services, said: Numerous schools and community youth groups have noted their interest in the Little Lights programme, and we are encouraging more to take part, before the final deadline on January 31.

The education programme is fascinating as it gives a real insight into the lighthouses of the north-east and our relationship with the sea. Furthermore, the pack contains age-appropriate information about cancer. A diagnosis of cancer, in a family, can have a significant impact on a childs emotional wellbeing.

"The Little Lights Education Programme aims to empower our future adults to manage their physical and emotional wellbeing and develop personal resilience which will provide them with lifelong strategies to employ, which will help them navigate through difficult times.

After getting creative in the classroom, teachers, parents and young people will see their 3D masterpiece on the art trail alongside those of contemporary artists at museums, libraries, galleries and leisure venues. After 10 weeks on public display, each little lighthouse sculpture will go back to the school or community to keep.

We urge schools and communities to be part of this unique event that will raise vital funds for CLAN Cancer Support and deliver significant benefits to teachers, pupils, and our community.

The deadline for schools taking part in the programme is January 31. To take part schools and community groups should visit http://www.lightthenorth.co.uk where they can download an education pack.

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Aberdeenshire schools urged to get creative and light the north - Buchan Observer

Cell Biology

Special delivery: McMaster physicists design super-human red blood cells to deliver drugs to specific targets within the body – Newswise

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Newswise A team of physicists from McMaster University has developed a process to modify red blood cells so they can be used to distribute drugs throughout the body, which could specifically target infections or treat catastrophic diseases such as cancer or Alzheimers.

The modified red blood cells are designed to circulate in the body for several weeks at a time, seeking out specific targets including bacteria, tumours or organs.

The technology, described in the online edition of the journal Advanced Biosystems, solves a major problem with current drug delivery methods that use synthetic molecules and cannot reach specific targets or are rejected by the body.

We call these super-human red blood cells. We think that they could work as the perfect stealth drug carriers which can outsmart our immune system, explains Maikel Rheinstdter, a senior advisor on the study and professor in the Department of Physics & Astronomy at McMaster.

The researchers have developed a method to open up the red blood cell, modify its outer cell wall, and replace its contents with a drug molecule, which would then be injected back into the body.

The hybrid appears and behaves as a normal red blood cell, but has a sticky surface which can attach itself to bacteria, for example, open up and release antibiotics exactly where they are needed.

We have combined synthetic material with biological material and created a new structure, which has never been done before in this way, says Sebastian Himbert, lead author and a graduate student in the Department of Physics & Astronomy at McMaster.

The entire process is very efficient and can be completed in one day in the lab, he says.

Researchers believe this targeted delivery method could help to minimize dosages and therefore, potential side effects. This is particularly important for very potent drugs used in cancer and Alzheimers disease, and the treatment of infections of potentially resistant bacteria.

The work was done in collaboration with Harald Stver, professor in the Department of Chemistry and Chemical Biology at McMaster, Janos Juhasz from the Juravinski Cancer Centre, and researchers at Saarland University in Germany.

A high res photo and video of researchers Maikel Rheinstdter and Sebastien Himbert can be found at this link: https://assets.adobe.com/public/907bc03f-19a0-4454-6dda-d1d10a57eb0a

Attention editors: A copy of the study can be found at the link below:

Adv. Biosys.2020, 1900185 Hybrid erythrocyte liposomes: functionalized red blood cell membranes for molecule encapsulation, Sebastian Himbert, Matthew J. Blacker, Alexander Kihm, Quinn Pauli, Adree Khondker, Kevin Yang, Sheilan Sinjari, Mitchell Johnson, Janos Juhasz, Christian Wagner, Harald D. H. Stver and Maikel C. Rheinstdter

Adv. Biosys.2020, 1900185

https://doi.org/10.1002/adbi.201900185

SEE ORIGINAL STUDY

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Special delivery: McMaster physicists design super-human red blood cells to deliver drugs to specific targets within the body - Newswise

Cell Biology

Artisan Bio Announces Global Research and Discovery Collaboration Agreement with Takeda to Develop Next-Generation Cell Therapy Products | More News |…

DetailsCategory: More NewsPublished on Wednesday, 15 January 2020 15:24Hits: 501

Multi-target collaboration combines Artisan Bio's proprietary synthetic biology platform with Takeda's Cell Therapy Expertise

DENVER, CO, USA I January 15, 2020 I Artisan Bio, Inc., a stealth cell therapy engineering company, today announced it has entered into a global research and collaboration agreement with Takeda Pharmaceutical Company Limited ("Takeda") for the discovery, development, and commercialization of novel cell therapy products.

Under the terms of the agreement, Artisan Bio will deploy its STAR platform and synthetic biology expertise to construct customized and precisely engineered cell therapies. Artisan will lead discovery efforts, including gene editing, and Takeda will be responsible for the development, manufacturing, and commercialization of the resulting cell therapy products.

"We are thrilled to collaborate with Takeda and combine our advanced cell engineering capabilities with Takeda's visionary cellular therapy programs," said Ryan T. Gill, CEO of Artisan Bio. "Many limitations that exist in current generation cell therapies can be addressed through the precision engineering of cells for enhanced performance. This collaboration will accelerate the availability of more effective next-generation cellular therapies for patients with high unmet needs."

About Artisan Bio:Artisan's vision is to design, build, and deliver cells and precision engineering processes thatadvance cellular therapies across a broad range of human health indications. The company's designer cell engineering and data analysisSTARplatform enables partners to more rapidly and cost effectively generate safer and more efficacious cell therapies. By engaging in strategic collaborations with innovativepartners, Artisan seeks to deliver customizable cellengineering solutions that meet the complexitiesassociatedwith next-generation cell therapies. Artisan has offices in Denver, Colorado and Copenhagen, Denmark.

For more information, please visithttp://artisancells.com/.

SOURCE: Artisan Bio

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Artisan Bio Announces Global Research and Discovery Collaboration Agreement with Takeda to Develop Next-Generation Cell Therapy Products | More News |...

Biochemistry

Curcumin Combined with Thalidomide Reduces Expression of STAT3 and Bcl | DDDT – Dove Medical Press

Mahnaz Mohammadi Kian, 1, 2 Mahdieh Salemi, 1, 2 Mohammad Bahadoran, 3 Atousa Haghi, 1, 4 Nasrin Dashti, 5 Saeed Mohammadi, 1, 2 Shahrbano Rostami, 1, 2 Bahram Chahardouli, 1, 2 Davood Babakhani, 1 Mohsen Nikbakht 1, 2

1Hematology Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran; 2Hematologic Malignancies Research Center, Tehran University of Medical Sciences, Tehran, Iran; 3Department of Biochemistry, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; 4Young Researchers & Elite Club Tehran Medical Sciences, Islamic Azad University, Tehran, Iran; 5Department of Medical Laboratory Sciences, School of Allied Health Sciences, Tehran University of Medical Sciences, Tehran, Iran

Correspondence: Mohsen NikbakhtHematology, Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, IranTel +982184902639Fax +982188004140Email m-nikbakht@sina.tums.ac.irNasrin DashtiDepartment of Medical Laboratory Sciences, School of Allied Health Sciences, Tehran University of Medical Sciences, Tehran, IranTel +989123583690Email dashti@tums.ac.ir

Introduction: Acute myeloid leukemia (AML) is a type of blood disorder that exhibits uncontrolled growth and reduced ability to undergo apoptosis. Signal transducer and activator of transcription 3 (STAT3) is a family member of transcription factors which promotes carcinogenesis in most human cancers. This effect on AML is accomplished through deregulation of several critical genes, such as B cell lymphoma-extra-large (BCL-XL) which is anti-apoptotic protein. The aim of this study was to evaluate the effect of curcumin (CUR) and thalidomide (THAL) on apoptosis induction and also the alteration of the mRNA expression level of STAT3 and BCL-XL mRNA on AML cell line compounds.Methods: The growth inhibitory effects of CUR and THAL and their combination were measured by MTT assay in U937 and KG-1 cell lines. The rates of apoptosis induction and cell cycle analysis were measured by concurrent staining with Annexin V and PI. The mRNA expression level of STAT3 and BCL-XL was evaluated by Real-Time PCR.Results: CUR inhibited proliferation and induced apoptosis in both KG-1 and U937 cells and this effect increased by combination with THAL. The expression level of STAT3 and BCL-XL was significantly down-regulated in KG-1 cells after treatment by CUR and THAL and their combination.Conclusion: Overall, our findings suggested that down-regulation of STAT3 and BCL-XL mRNA expression in response to CUR and THAL treatment lead to inhibition of cell growth and induction of apoptosis.

Keywords: acute myeloid leukemia, curcumin, thalidomide, STAT3, Bcl-xL

This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License.By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

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Curcumin Combined with Thalidomide Reduces Expression of STAT3 and Bcl | DDDT - Dove Medical Press

Biochemistry

The Future of Food – UC Davis

Food is more than the energy that fuels our bodies it is preventive medicine. Maybe not a cheesy chimichanga, but the type of food that is loaded with vitamins and proteins can maximize the benefits to the human body.

We need to look at the functional properties of food more closely so we can achieve the desired outcome, said Justin Siegel, associate professor of chemistry, biochemistry and molecular medicine, and faculty director for the Innovation Institute for Food and Health. Instead of focusing on the quantity of food which is a legitimate long-term concern globally lets hone in on creating quality food that possesses more active nutritional ingredients that deliver greater health benefits with every serving.

Siegel has a vision to transform the greater Sacramento region into the incubator pipeline for food science innovations. The initiative, dubbed Food Valley, would accelerate the commercialization of game-changing ideas across the food system by tapping into research, industry and policy. It would also prepare tomorrows food innovators and entrepreneurs through experiential learning programs.

Food Valley aims to patent its food innovations through developing technologies. These concepts can be grown into companies and potentially be a launchpad for Aggie entrepreneurs.

Siegel became interested in biotechnology as a kid. More recently, he thought about the possibilities of using biotech to disrupt the food systems industry. He co-founded PVP Biologics, a food biotech company, in 2016. PVP created a pill called KumaMax, which could help those who have celiac disease. KumaMax is currently in clinical trials, awaiting FDA approval.

Food Valley is about letting people experience freedom in what they are able to eat especially as it pertains to food allergies and restrictions, Siegel said. With modern technology we can both see the exact molecules that make up our food and manipulate those molecules to change how they interact with someones body.

No centralized hub for food innovations exists yet. Siegel said he believes UCDavis has the right ingredients to emerge as the leader.

Twenty years ago, this was science fiction, he said. Now we can do things we never thought possible. There is going to be a hub for food innovation, and UCDavis should be the place it happens.

This is one of several Big Ideas, forward-thinking, interdisciplinary programs and projects that will build upon the strengths of UCDavis to positively impact the world for generations to come. Learn more at bigideas.ucdavis.edu.

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The Future of Food - UC Davis

Biochemistry

Breakthrough gives insight into early complex life on Earth – The Guardian

For the first 2 billion years, life on Earth comprised two microbial kingdoms bacteria and archaea. They featured an innumerable and diverse variety of species, but, ultimately, life on Earth was not that exciting judged by todays standards.

Then, the theory goes, a rogue archaeon gobbled up a bacterium to create an entirely new type of cell that would go on to form the basis of all complex life on Earth, from plants to humans.

Now, for the first time, scientists have succeeded in culturing an elusive species of archaea believed to be similar to the ancestor that gave rise to the first sophisticated cells, known as eukaryotes. The work has been described as a monumental advance that sheds new light on this evolutionary milestone.

Nick Lane, professor of evolutionary biochemistry at UCL, described the work as magnificent, while a commentary by two other experts in the field said it marked a huge breakthrough for microbiology.

Like bacteria, archaea continue to thrive on Earth today. But despite the pivotal role they are thought to have played in the emergence of complex life there has been relatively little research on them. Many species are found in inhospitable environments and are incredibly difficult to grow in the lab.

The Japanese team behind the latest advance has dedicated 12 years to the effort, overcoming a series of setbacks along the way.

Their scientific odyssey began in 2006 with the collection of a sample of deep-sea mud, dredged up by a submersible from the 2.5km deep Omine Ridge off the coast of Japan. The mud was placed in a bioreactor and continuously fed with methane for more than five years.

Most organisms that have been cultured in the lab reproduce rapidly, can live in large numbers, and grow by themselves, said Masaru Nobu, of the National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan. The organism we isolated reproduces 1,000 times slower than E. coli, only lives in small numbers, and depends on symbiotic partners to grow.

Nobu and colleagues then took smaller samples from the reactor and placed them in glass tubes, which sat in the lab for another year before showing any obvious signs of life. The researchers painstakingly coaxed them along, feeding them a blend of nutrients including powdered baby milk. The cells took two to four weeks to replicate and divide, meaning each stage of the study took months.

While the epic experiment was running, a fortuitous discovery was made by a Dutch team, also researching archaea. They sequenced microbial DNA extracted from mud from a hydrothermal vent off the coast of Greenland. One intriguing genome stood out: it was clearly a member of the archaea, but dotted through its DNA were genes similar to those seen in eukaryotic cells.

Scientists called it the Asgard archaea and suggested that the ancestors of this evolutionary branch could have bridged the gap between basic and complex life billions of years earlier.

When the Japanese team sequenced their samples, genetic analysis revealed they had managed to cultivate the same Asgard archaea. Until this point, scientists had found out the genetic code, but had no idea what the organism actually looked like.

The latest work reveals that the Asgard archaea are small simple cells, but feature long tentacle-like structures reaching out of the cells. Not everyone agrees that they represent the origins of complex life. But the theorys proponents suggest that one of these cells could have engulfed a bacteria, with the bacteria then going on to become structures known as mitochondria, which act as an internal power supply in all complex cells today. Bacteria and archaea lack this internal architecture.

The Japanese team suggest that Asgards newly revealed spaghetti-like tendrils could have engulfed a passing bacteria and formed a symbiotic relationship with it. After several evolutionary leaps, the two organisms could have become one, more complex, cell type a primitive eukaryote.

The scenario is still speculative and is likely to remain under active debate for the next decade. Either way, the advance is likely to trigger a resurgence of interest in these under-explored microbes.

The importance of this work its hard to describe, said Lane. You see these genome sequences and try and reconstruct what the cell might look like, but you cant do that with any real power. Finally you see what the cell looks like and its not what anyone expected.

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Breakthrough gives insight into early complex life on Earth - The Guardian

Biochemistry

Astrobiologist talks about the possibility of invisible aliens, suggests the existence of silicon-based life form – International Business Times,…

NASA intern who found unpredicted type of Northern Lights

It was around a few days back that Dr Helen Sharman, who visited the Soviet Mir space station in May 1991, suggested the possibility of invisible alien forms that might be living among us on the earth. Now, Samantha Rolfe, a Lecturer in Astrobiology and Principal Technical Officer at Bayfordbury Observatory, University of Hertfordshire has talked about the possibility of alternate biochemistry, and the way in which this unknown biochemistry supports alien life.

Silicon-based alien life?

Rolfe made these comments in her recent article on The Conversation. In her article, Rolfe revealed that life may exist in a shadow biosphere, and due to limitations in modern technology, humans have not explored it.

"Life would exist in a "shadow biosphere". By that, I don't mean a ghost realm, but undiscovered creatures probably with different biochemistry. This means we can't study or even notice them because they are outside of our comprehension. Assuming it exists, such a shadow biosphere would probably be microscopic," wrote Rolfe.

As per Rolfe, silicon-based life could explain the existence of invisible alien life, as it is very similar to carbon, and has four electrons available for creating bonds with other atoms. "A popular suggestion for alternative biochemistry is one based on silicon rather than carbon. It makes sense, even from a geocentric point of view. Around 90% of the Earth is made up of silicon, iron, magnesium, and oxygen, which means there are lots to go around for building potential life," added Rolfe.

Rolfe believes that silicon-based aliens might be thriving on Saturn's moon Titan, or in other exoplanets. She also urged experts to think outside of the terrestrial biology box to detect such alien life forms.

Did advanced aliens visit earth?

However, Samantha Rolfe does not think advanced aliens that are technologically more advanced have visited the earth from the deep nooks of the universe. However, she made it clear that alien life forms might be harboring somewhere as carbon-based molecules were discovered on meteorites.

In the meantime, NASA chief scientist Dr Jim Green had recently predicted that alien life forms at least in its microbial form will be discovered on Mars within 2021. He also made it clear that humanity is not ready to accept the realities surrounding extraterrestrial existence.

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Astrobiologist talks about the possibility of invisible aliens, suggests the existence of silicon-based life form - International Business Times,...

Biochemistry

Bristol University uses Oracle Cloud Infrastructure to speed up smoking cessation drug discovery – ComputerWeekly.com

Scientists at the University of Bristol have published research showing how nicotine affects receptors in the brain as part of an effort to design drugs that will help smokers to quit.

They have done so using Oracle Cloud Infrastructure donated by the supplier and in collaboration with Achieve Life Sciences, a Seattle-based pharmaceutical company focused on the commercialisation of Cytisinicline, a plant-based alkaloid with a high binding affinity to the nicotinic acetylcholine receptor in the human brain.

According to the US National Institute on Drug Abuse, the majority of smokers would like to stop smoking, and each year around half try to quit permanently. Yet, only about 6% of smokers are able to quit in any given year. Smoking is the second most common cause of death worldwide.

The paper that issued from the Bristol research, A general mechanism for signal propagation in the nicotinic acetylcholine receptor family, was published in the Journal of the American Chemical Society in December 2019.

Two of the authors are from Oracles Cloud Development Centre in Bristol, Phil Bates and Gerardo Viedma Nunez.

Adrian Mulholland from the University of Bristols Centre for Computational Chemistry was co-lead author on the paper, along with Richard Sessions, senior research fellow at the School of Biochemistry at Bristol.

Mulholland told Computer Weekly: Our work shows how nicotine exerts its effects on nicotinic acetylcholine receptors. Understanding this should help us design better smoking cessation aids.

The study, led by led University of Bristol scientists but involving academics from other institutions, used Oracles cloud infrastructure. The researchers used new computational simulation methods to conduct 450 assessments of the biochemistry associated with the binding of nicotine to a subtype of nicotinic acetylcholine receptors, a mechanism believed to be responsible for the highly addictive nature of the drug.

Each simulation takes eight hours to run on a single cloud node, said Mulholland. If we had used our own high-performance computing facility, it would have taken 90 days to do what we did in five.

We are lucky at Bristol to have pretty good HPC resources, but what the Oracle Cloud enabled us to do was to run a new class of simulation non-equilibrium simulations, of which there are hundreds that have to be done in parallel. The Oracle Cloud enabled us to run them in a matter of weeks, whereas it would otherwise have taken us a year.

To understand why nicotine is so addictive, and to develop molecules to help people quit smoking, we need to understand how nicotine affects the nervous system. By harnessing the power of cloud computing, we can quickly observe how nicotine exerts its effects at the molecular level. This information can inform future drug development of new treatments for companies like Achieve.

According to a press statement from Achieve Life Sciences, Oracle and Bristol, the university and the pharmaceutical firm have teamed up to formulate molecules and potential treatments to combat addiction and neurological disorders based on smoking cessation compound in development, cytisinicline.

Cytisinicline is, according to the statement, a plant-based alkaloid with a high binding affinity to the nicotinic acetylcholine receptor. It is believed to aid in smoking cessation by interacting with nicotine receptors in the brain by reducing the severity of nicotine withdrawal symptoms and by reducing the reward and satisfaction associated with smoking.

The drug has been approved in Central and Eastern Europe for more than two decades, and has been used by more than 20 million people, according to the press statement.

The paper is one output of research originally funded by the EPSRC in 2016, with 724,000.

Mulholland said the beauty of being able to use cloud computing for this sort of scientific research lies in its capacity to enable collaboration. Im a great believer in different sorts of scientists working together to get the best results. And thats not about computation in its own right, but as part of a product development programme, he said.

Its helping to inform what sort of molecules people might make to test as potential medicines. Being able to do the computational simulations fast enough so that scientists can design and adapt their experiments quickly should accelerate drug development. We couldnt have done this two years ago.

The work brought together computational chemists, biochemists and research software engineers, working together to deploy the simulations of nicotine receptors.

The computer simulations methodology used in this particular area of neuroscience could also, said Mulholland, be applied to the study of schizophrenia and Alzheimers.

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Bristol University uses Oracle Cloud Infrastructure to speed up smoking cessation drug discovery - ComputerWeekly.com

Biochemistry

Invisible Aliens May Be Living Among Us. How Could This Be Possible? – Newsweek

Life is pretty easy to recognise. It moves, it grows, it eats, it excretes, it reproduces. Simple. In biology, researchers often use the acronym "MRSGREN" to describe it. It stands for movement, respiration, sensitivity, growth, reproduction, excretion and nutrition.

But Helen Sharman, Britain's first astronaut and a chemist at Imperial College London, recently said that alien lifeforms that are impossible to spot may be living among us. How could that be possible?

While life may be easy to recognize, it's actually notoriously difficult to define and has had scientists and philosophers in debate for centuriesif not millennia. For example, a 3D printer can reproduce itself, but we wouldn't call it alive. On the other hand, a mule is famously sterile, but we would never say it doesn't live.

As nobody can agree, there are more than 100 definitions of what life is. An alternative (but imperfect) approach is describing life as "a self-sustaining chemical system capable of Darwinian evolution," which works for many cases we want to describe.

The lack of definition is a huge problem when it comes to searching for life in space. Not being able to define life other than "we'll know it when we see it" means we are truly limiting ourselves to geocentric, possibly even anthropocentric, ideas of what life looks like. When we think about aliens, we often picture a humanoid creature. But the intelligent life we are searching for doesn't have to be humanoid.

Sharman says she believes aliens exist and "there's no two ways about it." Furthermore, she wonders: "Will they be like you and me, made up of carbon and nitrogen? Maybe not. It's possible they're here right now and we simply can't see them."

Such life would exist in a "shadow biosphere." By that, I don't mean a ghost realm, but undiscovered creatures probably with a different biochemistry. This means we can't study or even notice them because they are outside of our comprehension. Assuming it exists, such a shadow biosphere would probably be microscopic.

So why haven't we found it? We have limited ways of studying the microscopic world as only a small percentage of microbes can be cultured in a lab. This may mean that there could indeed be many lifeforms we haven't yet spotted. We do now have the ability to sequence the DNA of unculturable strains of microbes, but this can only detect life as we know itthat contain DNA.

If we find such a biosphere, however, it is unclear whether we should call it alien. That depends on whether we mean "of extraterrestrial origin" or simply "unfamiliar."

A popular suggestion for an alternative biochemistry is one based on silicon rather than carbon. It makes sense, even from a geocentric point of view. Around 90 percent of the Earth is made up of silicon, iron, magnesium and oxygen, which means there's lots to go around for building potential life.

Silicon is similar to carbon, it has four electrons available for creating bonds with other atoms. But silicon is heavier, with 14 protons (protons make up the atomic nucleus with neutrons) compared to the six in the carbon nucleus. While carbon can create strong double and triple bonds to form long chains useful for many functions, such as building cell walls, it is much harder for silicon. It struggles to create strong bonds, so long-chain molecules are much less stable.

What's more, common silicon compounds, such as silicon dioxide (or silica,) are generally solid at terrestrial temperatures and insoluble in water. Compare this to highly soluble carbon dioxide, for example, and we see that carbon is more flexible and provides many more molecular possibilities.

Life on Earth is fundamentally different from the bulk composition of the Earth. Another argument against a silicon-based shadow biosphere is that too much silicon is locked up in rocks. In fact, the chemical composition of life on Earth has an approximate correlation with the chemical composition of the sun, with 98 percent of atoms in biology consisting of hydrogen, oxygen and carbon. So if there were viable silicon lifeforms here, they may have evolved elsewhere.

That said, there are arguments in favour of silicon-based life on Earth. Nature is adaptable. A few years ago, scientists at Caltech managed to breed a bacterial protein that created bonds with siliconessentially bringing silicon to life. So even though silicon is inflexible compared with carbon, it could perhaps find ways to assemble into living organisms, potentially including carbon.

And when it comes to other places in space, such as Saturn's moon Titan or planets orbiting other stars, we certainly can't rule out the possibility of silicon-based life.

To find it, we have to somehow think outside of the terrestrial biology box and figure out ways of recognising lifeforms that are fundamentally different from the carbon-based form. There are plenty of experiments testing out these alternative biochemistries, such as the one from Caltech.

Regardless of the belief held by many that life exists elsewhere in the universe, we have no evidence for that. So it is important to consider all life as precious, no matter its size, quantity or location. The Earth supports the only known life in the universe. So no matter what form life elsewhere in the solar system or universe may take, we have to make sure we protect it from harmful contaminationwhether it is terrestrial life or alien lifeforms.

So could aliens be among us? I don't believe that we have been visited by a life form with the technology to travel across the vast distances of space. But we do have evidence for life-forming, carbon-based molecules having arrived on Earth on meteorites, so the evidence certainly doesn't rule out the same possibility for more unfamiliar life forms.

Samantha Rolfe is a Lecturer in Astrobiology and Principal Technical Officer at the Bayfordbury Observatory, University of Hertfordshire, U.K.

Views expressed in this article are the author's own.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Invisible Aliens May Be Living Among Us. How Could This Be Possible? - Newsweek