Jorge, Plants, Trees

In sharp contrast to the frosty mornings and cold evenings, fiery hues and bright coloured fruit can liven up your Autumn. Cultivars of crabapple and rowan can produce pink, yellow and red fruit, which are perfect for wildlife, while maples and beech can create gorgeous palettes of red, orange and yellow. Now without further ado, here are six trees with fantastic autumn colour.

Maple Trees

An essential part of Autumn iconography, the red maple (Acer rubrum) can be found throughout the UK’s public parks. Introduced all the way back in 1656, the tree will produce a profusion of red, orange and yellow, before turning a vivid red. Highly versatile, the tree can be found growing in a wide range of conditions in its native North America and is suitable for urban settings as it is tolerant of pollution.

Unlike its larger cousin, the japanese maple (Acer palmatum) is suitable for all gardens and can be grown in containers. Indigenous to East Asia, the tree can be found growing at heights up to 1100m, hence its other name the mountain maple. Come Autumn, the tree’s dissected leaves will turn a deep red. The palmatum has many quirky cultivars including ‘Butterfly’ with its cream-tinged green leaves that turn pink; ‘Atropurpureum’ with scarlet red Autumn foliage; and ‘Sango-kaku’ with its gorgeous coral coloured bark and stunning foliage.

Beech Trees

Picture Credit: Jean-Pol GRANDMONT licensed under CC BY 3.0.

Another typical Autumnal tree, the common beech (Fagus sylvatica) is a large, majestic tree with great spectrum of colours. Reaching up to 50 metres in the wild, although commonly 30, it was once believed that the tree is native to southern England, but not the North where it is sometimes removed. Researchers now believe the tree was first introduced to Southern England by Neolithic humans who sought its nuts for food, making it a non-native species. Trees in the North, on the other hand, were introduced by Vikings in the first millennium. Thankfully, most trees sold are limited in height by their rootstock, and are thus suitable for most gardens.

The Sweet Gum

Picture Credit: Famartin licensed under CC BY-SA 4.0.

Similar to maple and beech, the sweet gum (Liquidambar styraciflua ) is notable for its conflagration of colour with its sharp five-pointed leaves turning red, yellow and purple. First introduced to Europe in 1681 by John Banister, one of the first university trained botanist, the species is also notable for deeply ridged bark, known as alligator bark in America.

Crabapples

Severely underrated, the humble crabapple will produce attractive foliage and bright and colourful fruits, which can last well into winter. The species is hardy, versatile and great for wildlife, being native to the UK. The tree will produce beautiful blossom come Spring and serves as a great pollinator for apples. Notable cultivars include ‘Butterball’, ‘John-Downie’, ‘Evereste’ and ‘Red Sentinel’ with yellow, scarlet-orange, red and yellow-orange fruit respectively. Special is ‘Butterball’ that can produce six different colours throughout the year.

Rowan Trees

Similar to the crabapple, rowans produce fantastic coloured berries that can last well into winter, providing an essential source of sustenance for birds. Hardy and versatile the species is suitable for most soils, and with many different sized cultivars, there is a tree for every garden.The most famous is the native Sorbus aucuparia with red berries and slender leaves, which turn yellow in Autumn. Simply stunning, however, are the cultivars ‘Pink Pagoda’ and ‘Joseph Rock’. The former produces gorgeous pink berries, which are a favourite for birds, while the latter looks amazing with its deep red pinnate leaves contrasted with bright yellow berries.


Cherry Trees

Commonly thought as a tree for Spring, many cherries are ideal ornamentals for Autumn hues. One of the best has to be the ‘Autumnalis Rosea’ that will flower intermittently from November to April with clusters of small semi-double rosy-pink blossom. Other varieties such as ‘Fragrant Cloud’, ‘Sargent’s Cherry’ and ‘Umineko’ will produce fiery displays, with the Sargents among the first trees to colour up. ‘Fragrant Cloud’ is especially beautiful with its upright form. Worthy of note is the ‘Tibetan Cherry’ with its smart coppery-brown bark that will look beautiful regardless of season.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Animals, Gardening, Jorge, Plants

It has long been reported that plants respond to sound and the belief that plants can respond to music has taken root in the popular imagination. We’ve all heard stories of farmers and hobbyist alike serenading their plants and producing miraculous results. But do these experiments have any scientific underpinnings? Unsurprisingly, there is very little scientific research into the subject and a serious dearth of scientific proof that plants can respond to sound, let alone music. However, scientists have been repeatedly surprised in what plants can respond to and it has been discovered that plants have at least 20 different senses. Will hearing be the next?

The misconception that plants can respond to music has its origin in poorly carried out scientific experiments, wishful thinking, the mixing of science and spirituality of the new age movement, and misreporting by the media.

Experiments documenting the effects of music on plant growth date back to at least 1962 when T.C. Singh, head of the Botany Department at India’s Annamalia University, reported significantly improved growth of balsam plants exposed to music. His ideas were inspired by the Indian plant physiologist, Jagadish Chandra Bose, who spent a lifetime investigating the responses of plants to environmental stimuli, concluding that plants could both feel pain and understand affection. Research continued with Luther Burbank, an American botanist and horticulturalist, who concluded plants possess 20 sensory perceptions. All of this was preceded by Charles Darwin’s early investigations into plant perception, who once played the bassoon to a Mimosa plant, but concluded it had no effect.

Bose, a polymath, conducted research in a range of fields and made his inventions public to develop his research. Here he is pictured in the Royal Institution circa 1897.

The findings of the above researches were compiled into The Secret Life of Plants (1973), by Peter Tompkins and Christopher Bird. The book, considered a piece of fiction by many scientists, was underpinned by quacky new-age ideas and took into account many questionable experiments and studies including the work of Dorothy Retallack, who eventually published the The Sound of Musical Plants in the same year.

Retallack, an undergraduate student in music, had to take a biology module as part of her course and decided to investigate the effects of music on plant growth. Convinced that rock music was having a negative effect on the nation’s youth, she decided to test how the different genres would affect plants. Unsurprisingly, she found that rock music did have a highly negative effect on plants, causing them to wilt. By contrast, Ravi Shankar’s Indian sitar music led them to thrive. The experiment was fraught with shortcomings with a small sample size (5), insufficient replicates, and plants located in different environments.

The Secret Life of Plants sold well and many of its ideas would seep into the popular imagination. The book would even get its own motion picture adaptation, soundtracked by Stevie Wonder, released in 1979. The score would be expanded and released in the same year as Journey Through “The Secret Life of Plants”. It was made with the film’s producer describing the experiments to Wonder, the final result a mix of instrumental and pop songs, with the best the catchy Outside My Window.

Playing music to plants was a phenomena that preceded the book and musicians even composed music to be played to plants such as Mort Garson’s Mother Earth’s Plantasia. Described on the linear notes as “warm earth music for plants…and the people that love them”, the album was produced using the Moog synthesizer, of which Garson was an early adopter.

So, why do people consistently report music improves plant growth? A good answer comes from a series of experiments described in Peter Scott’s Physiology and Behaviour of Plants. The first experiment tests whether rock or classical would produce faster germination vis-a-vis a control exposed to no music. The results show that while both rock and classical increased germination against the control, there is no difference between the genres. This may seem surprising, but the second experiment adds an extra control – a small fan that blows away the heat generated from the speakers. The results show that there is no difference in germination between the plants exposed to music and the control. The faster germination originating from the heat of the speakers, not the plants responding to music.

Another possible explanation is that those who play music to plants are more likely to create conditions suitable for plant growth. Even if music has no effect on plants, the extra care and attention will, whether it be sufficient watering or correcting nutrient deficiencies for example.

Is there any reason to believe that plants can respond to sound? According to Daniel Chamovitz, professor of Life Sciences at Tel Aviv University, it is possible that we are simply performing the wrong tests. Evolution takes place extremely slowly and music is not an evolutionary pressure on plant development. We need to first identify the ecologically relevant sounds that could affect how a plant develops and adapts to its environment.

Furthermore, it is not necessary for organisms to have complex ears to pick up sound waves as a range of morphological features will suffice. Snakes, for example, use their jawbones to pick up ground-borne vibrations and deliver acoustic information to their mechano-sensory system. The ability to respond to sound may be useful for plants as it allows energetically cheap signalling that could be used for an array of functions.

Both frogs and birds have no outer ear, yet possess more acute hearing than humans.

There are some promising experiments that appear to document plants responding to sound, although increased repetition and further studies will be needed to convince the wider community.

One experiment found that the roots of maize plants grew towards the source of sound, especially at frequencies between 200 and 300Hz and emitted acoustic emissions themselves. Another found that specific frequencies between 125Hz and 250Hz made certain genes more active, while frequencies at 50Hz made them less active. Lastly, one experiment found that plants would respond to vibrations mimicking the sound of a caterpillar’s jaws chewing, producing a class of chemicals poisonous to caterpillars as a response.  

So, what is going on here? These experiments indicate that plants respond to and emit sound when it is defined as vibrations that travel through the air or another medium. These sounds may be not be recognisable to us, but it is sound nonetheless. Ultimately, the identification of the mechanisms through which sound is detected and emitted will be key in transforming the hypothesis into a veritable theory. The how explaining the why.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Jorge, Plants, Trees

Cherry trees are an important, multifaceted part of Japanese culture with its blossom (sakura) featuring on everything from political and military insignia to popular designs and coinage. Despite this, cherry tree blossom is fleeting with the flowers’ lifespan usually lasting only a week. It is this exact quality that explains the trees’ enduring appeal  – the symbolic representation of the transient nature of life, and beauty itself, which is celebrated with the popular custom of hanami, in which Japanese picnic under the bloom.

Over the centuries, the sakura’s meaning has evolved, but also become tightly interwoven with Japan’s cultural fabric. Not merely because of its beauty, but because political groups have sought to use the symbol for their own ends. Originally, the cherry blossom was connected to Japanese folk religions due to its phenology  – that is its capacity to flower during the changing of the seasons. Agricultural communities came to believe that the falling petals transformed into the deity of rice paddies. It was in this period that trees began to be transplanted into towns.

712 AD gives us the first written reference of cherry blossom. The Empress Gemmei, fearful of neighbouring Tang Dynasty’s power, sought to compile an account of Japan’s unique development and distinctiveness from its neighbours. This compilation, Kojiki, raised the status of the cherry blossom (in contrast to China’s plum blossoms), beginning the custom of hanami in which nobles and commoner alike celebrated under the blossom.

The Heian period (794-1185) saw the spread of new sects of Buddhism throughout the Japanese landmass and witnessed the development of the concept mono no aware. The term is culturally significant and helps explain Japan’s love for the cherry tree blossom. It refers to an awareness and acceptance of impermanence as a reality of life. This is perhaps best demonstrated through this segment of Japanese television. Throughout the centuries, representations of sakura also proved highly popular in Japanese art as demonstrated in the art-deco masterpiece celebrating speed and modernity below.  

The 12th century saw the rise of the samurai, whose power was consolidated with the establishment of a feudal system under the shogun Minamoto no Yoritomo. Much like lords in Europe, samurai were provided with estates in return for military service and were motivated by their own code of chivalry, known as bushido. Part of the bushido’s code was an identification with cherry blossom as it fell at the moment of its greatest beauty, symbolising an ideal death. The samurai decorated their equipment with emblems of cherry blossom.

The Meiji restoration of 1868 saw the end of the shogunate and the establishment of the Empire of Japan. It began a process of centralisation, which reclaimed governing authority from the shoguns and samurai. Newly established, the Japanese Imperial Army took over the defense of the state, resulting in samurai losing their social status and privileges. Keen to reconfigure the Bushido code, Japanese were deemed of noble character, able to face death without fear and willing to die like beautiful falling cherry petals for the Emperor. In 1969, the Emperor set up the Yasukuni Shrine as a memorial devoted to fallen soldiers. It is lined with cherry blossoms, supposedly to console soldier’s souls.

Photo credit: Wiiii. Licensed under  CC BY-SA 3.0.

From the beginning of the Meiji period and until the end of WW2, the Japanese government sought to use cherry blossom symbolism as a means to bind the country together. After witnessing the occupation and division of neighbouring states, including the once mighty China, the state felt it necessary to create a strong, shared national identity to prevent against fracture. This establishment of the national essence of Japan is known as kokutai.

In 1910, the city of Tokyo sent 2,000 trees to the U.S. as a gift to President William Howard Taft, who had previously spent time in the Far East. These died on the way, but were replaced with a second batch that were planted along the Potomac and grounds of the White House in 1912. These trees proved popular and celebrations would eventually evolve into the annual Cherry Blossom Festival. Interestingly, cuttings from these trees would be sent back to Japan to restore the original collection, which were badly damaged in WW2.

In WW2, the Empire again sought to utilise the Bushido code to inspire their troops. They revived the medieval proverb “hana wa sakuragi, hito wa bushi” that means as the cherry blossom is the first among flowers, so the warrior was first among men. In 1944, the Empire resorted to kamikaze operations in an effort to save Japan from defeat. Tokkotai, or kamikaze planes, were painted with cherry blossoms and pilots affixed branches to their uniforms.

Photo credit: Error. Licensed under CC BY-SA 3.0.

In March 2011, a tsunami struck Japan, devastating its coastal communities. The aftermath was documented in the Oscar-nominated “The Tsunami and the Cherry Blossom” that includes a Japanese man’s reflections on the strength of the cherry tree to live on in spite of the devastation. The tree constituted an inspiration to continue living as if “the plants are hanging in there, so us humans better do it too”.

Today, cherry blossom helps mark the beginning of the financial and academic year in Japan, although the date of flowering is dependent on temperature. In recent decades, cherry blossom has flowered increasingly early – a fact put down to global warming. The blossoms are big business for Japan with the cherry blossom season attracting thousands of tourists. The countdown is televised with the Cherry Blossom Forecast documenting the advance of the blooms from south to north. Retailers cash in by offering a assortments of cherry blossom goods including many culinary delights such as sakura pepsi, crisps and tea.

And of course, there is hanami that is still widely celebrated throughout Japan. The custom takes two forms: one that involves partying (sakura parties) and the other that involves a more traditional observance of the blossoms (umeni). Like Christmas, hamani celebrations often involve special dishes and drinking of alcohol. Hanami at night is known as yozakura and many public places will hang up lanterns to facilitate such events.

Photo credit: Japanexperterna.se. Licensed under CC BY-SA 3.0. 

So to summarise, cherry blossom are a huge part of Japanese culture representing the bravery of soldiers, the philosophical notion of mono no aware, peace and friendship with other countries, celebration and Japan itself.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Current Issues, Jorge, Plants

Unlike genetically modified crops, mutation breeding goes largely under the radar, but has been ongoing since at least 1942 when scientists Freisleben and Lenn induced mildew resistance in barley through the use of X-rays. The same scientists coined the term in 1944, defining it as “the utilisation of induced mutations in crop improvement”. Mutations are the “sudden heritable change in an organism” and crop improvement is induced “desirable changes in the genetic constitution of plants” and improved “performance of a cultivated variety” whether that be increased drought resistance or early flowering (and hence fruiting).

Standing at over 30 billion dollars, the seed market is a huge industry with such firms as the maligned Monsanto, which has run into public disdain and increasingly legislative hurdles as it tries to introduce new GM varieties into the world’s markets. A large chunk of this is mutation breeding that has no such regulation and offers an opportunity for companies to circumvent anti-GM laws and public scrutiny, while introducing new patented strains of seeds.

Before delving into the science and the question of whether foodstuffs derived mutagenesis are dangerous, it will be first worthwhile telling the fascinating history of mutation breeding.  

Mutation breeding was first proposed at the turn of century when Hugo de Vries suggested using radiation to induce mutations in plants and animals. By 1927 his ideas were confirmed when scientists Gager and Blakeslee carried out radium ray treatment of a Datura stramonium, inducing mutations. It was however Hermann J. Muller’s work in the 1910s and 1920s that provided the chief principles of spontaneous gene mutation, which eventually won him the Nobel Prize in Physiology and Medicine in 1946.

Mutation breeding achieved popularity in the 1950s, when it became part of the atoms for peace movement – a movement dedicated to the use of atomic energy for peaceful ends. The movement was kickstarted by the United States government that funded both research into peaceful applications of the technology and the construction of nuclear power plants around the world. The program was seen as a way to resolve the atomic dilemma as summarised in Dwight D.Eisenhower’s 1953 speech to the U.N. General Assembly that the “miraculous inventiveness of man shall not be dedicated to his death, but consecrated to his life”. This speech was followed by multiple conferences in the 50s that sought to bring together scientists from both East and West and reduce animosity between the two blocs.

The atoms for peace symbol, used during the 1955 Atoms for peace conference.

As part of the research into the application of atomic technology, mutation breeding was funded with the establishment of gamma gardens, in which crops were arranged in concentric circles around around a radiation source – usually a cobalt-60. The experiments were crude with crops near the source simply dying, and the ones further away riddled with growth abnormalities. It was the ones further away apparently healthy, but with alterations that were of interest.

Some experiments proved fruitful and gave us varieties that overcame limitations and now dominate as a percentage of production. Peppermint for example was extremely susceptible to Verticillium wilt, a fungal disease and cause of plant death, and it was experiments at the Brookhaven National Laboratory that led to the release of the ‘Todd’s Mitcham’ cultivar. A variety which underpins the $930 million global mint oil industry, which is used in everything from chewing gum to toothpaste. Another resultant variety from such experiments is the ‘Rio Star’ grapefruit, which is more red in colour and produces more flesh and juice. The variety accounts for 75% of grapefruit production in Texas.

Atoms for peace inspired certain sections of the public to conduct their own experiments such as Muriel Howorth in the United Kingdom and C.J. Speas in the United States, part of the atomic gardening movement.

Muriel, a laywoman, was extraordinarily passionate about the technology and promoted all things nuclear: publishing books (including Atomic Gardening for the Layman) and journals, forming multiple societies (including the Atomic Gardening society) and even staging a “Radioactivity Jubilee”. She was a maverick, who at the time was the only person speaking to women about the new science, founding the Ladies Atomic Energy Club. In 1959, she was the host of a dinner party of the Royal Commonwealth Society and decided to surprise her guests with irradiated peanuts as big as almonds. To her disappointment, they did not take off. Unruffled, she planted the peanuts in her greenhouse, which upon growing rapidly to two feet, she phoned the press to make the best out of a bad situation.

Holworth presenting her two-foot peanut plant to Beverley Nichols, a popular garden writer at the time.

C.J. Speas, another enthusiast, managed to obtain a license from the Atomic Energy Commission for a cobalt-60 source, which he encased in a cinderblocks in his back garden. From this he irradiated trays of seeds of which he reportedly sent millions (of seeds) to the Atomic Gardening Society, who distributed them to nearly a thousand members. He used to give tours of his cinderblock bunker to tourists and school groups. Separately, as pictures from Life magazine document, ‘super atomic energized seeds’ and ‘atom blasted seeds’ were sold at store and fairs in the late 50s and early 60s.

Atom-blasted seeds on sale in 1958. Photo by Grey Villet for Life.
Speas giving a tour of his bunker. Photo by Grey Villet for Life.

Today, mutagenesis is practiced by chemical companies and conglomerates such as BASF and DuPont. (It is important to mention that mutagenesis can be instigated by three classes of agents – biological, chemical and physical mutagens, so radiation is not necessarily involved.) Although, the legacy of Atoms for peace lives on in the work of the International Atomic Energy Agency, which is commemorating its sixtieth birthday, and the Food and Agriculture Organization of the United Nations, who through their technical cooperation programme contribute to the UN sustainable development goals through providing scientific support to member states.

One fascinating example of mutagenesis was carried out by the RIKEN Nishina Center for Accelerator-Based Science, Japan, who used heavy ion beams to induce mutations in a cherry tree, creating a new cherry blossom that blooms in all four seasons. The tree is unique in that it does not need a period of cold weather to trigger growth in spring and ostensibly produces three times more flowers than standard trees and stays in bloom for twice as long when blooming in April.

Interestingly, mutagenesis has proved highly profitable for Japan with the country investing $69 million on mutant breeds from 1959-2001, which have yielded $62 billion worth of goods in the same period. Hence, bringing new cultivars to market through mutation breeding is significantly cheaper than through GM, with Monsanto spending up to $200 million to launch a single GM product. And as things stand, this offers a huge incentive for firms to abandon GM methods and switch to mutation breeding.

How does mutation breeding work?

Mutation breeding is a two stage process involving mutation induction and detection. It is extremely effective, increasing the natural mutation rate by a thousand to a million fold. Mutation induction works by damaging an organism’s cellular structure, causing a change in the DNA, which when not repaired by the cell’s repair mechanism, lives on as a heritable mutation. These mutations are induced through two classes of mutagens – chemical and physical with the latter generating 70% of released mutant variables.

Physical mutagens are primarily induced through ionising radiation from gamma and x rays. These rays form part of the electromagnetic spectrum, just like visible and infrared light, except are extremely high energy. Chemical mutagens work differently involving chemical reactions within the genome, which alter a section of the DNA. Unlike physical mutagens, chemical mutagens are varied, with a number of agents, altering DNA through different causal chains.

With physical mutagens, mutations can be induced through a number of methods such as the aforementioned gamma gardens or fields. Alternatively, seeds or plant propagules can be placed within a gamma cell with a Cobalt-60 source (similar to Speas) or simply irradiated with an x ray machine. More recently, ion beam technology has been used to introduce mutations.

Plants arranged in concentric rings around a Cobalt 60 source. C.1959 at the Brookhaven National Laboratory.

Usually, scientists set upon finding the optimal dose that will be high enough to cause mutations, without putting a halt to germination or growth. And with most methods, scientists will go through thousands of plants before a mutation imparts a desirable characteristic. In addition, as many mutations are recessive, these characteristics are not revealed till subsequent generations.

The true art of mutation breeding lies in the mutation detection stage that has long been a bottleneck in plant breeding due to the reliance on phenotypic screening. Put simply, genotypes and phenotypes are used to distinguish between a plant’s hereditary information and an organism’s observed properties. As these observed properties are influenced by both the environment and a plant’s genetic code, scientists can’t be sure an observed trait originates from genetics. Rather a plant’s ostensible disease resistance may originate from an absence of a pathogen, as opposed to an inbuilt resistance to disease.

More recently, the introduction of genotypic screening has allowed scientists to distinguish between putative mutants and true mutants, by identifying variations that are inherited and linked to a trait of interest. By identifying a variation in the DNA, populations can be then assayed, leading to the identification of molecular markers that allows breeders to introduce mutant traits into different cultivars for improvement. Next, putative mutants are evaluated under a set stringent conditions, leading to mutant confirmation.  

Are foodstuffs derived from mutants dangerous?

As previously mentioned, unlike GMO, mutagenesis is unregulated and to some hasn’t received the attention it deserves. Accordingly, the National Academy of Sciences has stated the risks of creating unintended genetic consequences from mutation breeding is higher than any other techniques due to the imprecise nature of the method and the random alteration of DNA. However, they also state that the risks are small relative to the incidence of other foodborne illnesses. Unsurprisingly, BASF, states that the crops are safe with the technique being used for many decades without concern.

In line with this, mutant breeds are relatively widespread, especially in Asia where countries such as China, India and Japan produce over 10% of their produce from such varieties. According to the UN, there are over 3200 mutant varieties released for commercial use in more than 210 plant species for use in more than 70 countries. Furthermore, there may be many more varieties with mutant genetic code that we have simply forgotten about due to the long history of mutant breeding. So, it is probable such foodstuffs have already entered our food supply.

Ultimately, mutation breeding has proven a vital tool to increase crop yields in our increasingly hungry world. Due to the work of the UN, mutant strains are widely used throughout the developing world and have done much to alleviate hunger. Certainly, neither GM, nor mutagenesis derived varieties should receive a blanket ban, but be assessed on a case-by-case bases. As with many ethical dilemmas, the truth lies hidden in the details.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

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