Tuesday, April 25, 2023

Recycling lake sediments for crop production: A sustainable solution for closing the phosphorus cycle

Peer-Reviewed Publication

UNIVERSITY OF HELSINKI

Lake Mustjärv aerial view 

IMAGE: AERIAL VIEW OF THE EXCAVATION PROCESS AT EUTROPHIC LAKE MUSTIJÄRV, LOCATED IN VILJANDI, ESTONIA, TAKEN IN AUGUST 2016. view more 

CREDIT: KRISTJAN LUST

A four-year field experiment conducted on the shores of restored Lake Mustijärv in Viljandi, Estonia, has revealed that recycling phosphorus-rich lake sediments back to agriculture could have positive impacts on crop production.

The study was conducted by doctoral researcher Mina Kiani and the AgriChar research group, and it is globally the first of its kind to cover the environmental aspects of recycling lake sediments to agriculture over several years. Kiani defends her thesis on 21 April at the University of Helsinki Faculty of Agriculture and Forestry.

The study aimed to find a sustainable solution for closing the leaking agricultural phosphorus (P) cycle by recycling P-rich lake sediments back to agriculture and helping the restoration of the eutrophic lake by sediment removal. The experiment involved excavating all 7500 m3 of sediment from the 1-hectare shallow eutrophic Lake Mustijärv, which was then used as a growing medium for grass production. The sediment was also analysed for various essential nutrients, including P, sulphur (S), calcium (Ca), magnesium (Mg), boron (B), zinc (Zn), and copper (Cu).

The results showed that sediment-based growing media sustained the grass biomass yield in the field condition, with the sediment being rich in organic matter and a good source of several essential nutrients. Additionally, the sediment continuously provided a moderate supply of N to the plants over the four-year field experiment.

The study also investigated the environmental impacts of various sediment application methods, including greenhouse gas emissions, N and P leaching, aggregate stability, and soil biota. Sediment-based growing media had different bacterial and fungal community compositions compared with soil, and it increased the risk of P and mineral N leaching. Biochar application increased the amount of N taken up by the plants but did not significantly reduce emissions or leaching.

The sediment application rate should be adjusted to match crop requirements, similar to how fertilizers are applied. This can help minimize nutrient leaching back into the lake and further help mitigate eutrophication of the lake.

Furthermore, in this project, the changes in P dynamics at the sediment–water interface in the restored lake were examined during a two-year follow-up period. Theoretically, no markable sediment P release could appear after complete sediment removal. Nevertheless, a large pool of releasable P was rebuilt soon after sediment removal due to an exceptionally high nutrient flow from the catchment. Particularly large quantities of sediment, most likely originating from the stream bed cleaning upstream of the lake, concentrated into the sediment accumulation basins, i.e. deeper parts of the lake created as a part of the lake restoration project. Regularly emptying such sediment accumulation basins may help to efficiently entrap point source nutrient inputs and facilitate future lake restoration efforts.

Mina Kiani and Olga Tammeorg are collecting sediment samples from the Lake Mustjärv to evaluate its condition after being restored through complete sediment removal.

CREDIT

Priit Tammeorg

Chicken breeding in Japan dates back to fourth century BCE

Peer-Reviewed Publication

HOKKAIDO UNIVERSITY

Red junglefowl, Malaysia 

IMAGE: RED JUNGLEFOWL, THE SPECIES FROM WHICH THE CHICKEN WAS DOMESTICATED (PHOTO: MASAKI EDA). view more 

CREDIT: MASAKI EDA

Conclusive evidence of chicken breeding in the Yayoi period of Japan has been discovered from the Karako-Kagi site.

The chicken is one of the most common domesticated animals, with a current estimated population of over 33 billion individuals. They are reared for their meat and eggs, and may be kept as pets.

The chicken is believed to have been domesticated in Southeast Asia about 3500 years ago, following which they were carried to all corners of the world. The exact date of introduction of chicken breeding to Japan is under debate, as there are no historical records and archeological evidence is inconclusive.

Professor Masaki Eda at the Hokkaido University Museum led a team to uncover the earliest conclusive evidence of chicken breeding in Japan. The findings, which show chickens were bred in the Karako-Kagi site, a settlement from the Yayoi period [5th century BCE to around 2nd century BCE], were published in the journal Frontiers in Earth Sciences.

“Chickens and their wild relatives belong to a family of birds called Phasianids, which includes pheasants, turkeys and quail,” explains Eda. “Bones of juvenile phasianids recovered from archeological sites could not indisputably be identified as belonging to chickens or to similarly sized wild pheasants. Identification of juveniles is important, as it would indicate that breeding of chickens took place.”

The Karako-Kagi site, in what is now Tawaramoto Town, Nara Prefecture, is considered to be a settlement that played the role of a leader of the Kinki region during the Yayoi period. There are multiple archeological digs in the area; one such dig, at the 58th research point, yielded ten phasianid bones, four of which belonged to juvenile birds.

The team used a technique called Zooarchaeology by Mass Spectrometry (ZooMS) to analyze the collagen in two of the juvenile phasianid bones. Previous work by Eda had shown that domestic chicken and Japanese wild pheasants had different ZooMS fingerprints; ZooMS revealed that both the two bones belonged to chickens. The collagen from one of the bones was also carbon dated to 381–204 BCE, corresponding to the middle Yayoi period.

“Ten of the eleven previously-discovered bones of adult chickens from this period have all belonged to males; hence, it was thought chicken breeding could not have occurred on the Japanese archipelago,” Eda elaborated. “By identifying bones from juvenile chickens, we provide clear evidence that breeding did occur in that time period—which is also the earliest time chickens could have been introduced to Japan. In addition, Karako-Kagi is considered an important trade hub of the Yayoi period, so there is a possibility that this status is a factor in chicken breeding during the period.”

The archeological discoveries of chickens in Japan show that the human-chicken relationship was very different from that revealed by archeological studies in China and in Europe. Future research will focus on understanding these differences.

The bones examined in this study were discovered at the 58th research point in the Karako-Kagi site (Masaki Eda, et al. Frontiers in Earth Science. April 20, 2023).

The two bones from the Karako-Kagi site identified as belonging to juvenile chickens by the Zooarchaeology by Mass Spectrometry technique (Masaki Eda, et al. Frontiers in Earth Science. April 20, 2023).

CREDIT

Masaki Eda, et al. Frontiers in Earth Science. April 20, 2023

African penguins: climate refugees from a distant past?

A new study on the paleo-historical geographic range of the endangered African penguin since the last Ice Age paints a grave picture of a species in steep decline

Peer-Reviewed Publication

TAYLOR & FRANCIS GROUP

The paleo-historical picture of the geographical range of African penguins over the past 22,000 years 

IMAGE: THIS IS THE PALEO-HISTORICAL PICTURE OF THE GEOGRAPHICAL RANGE OF AFRICAN PENGUINS OVER THE PAST 22 000 YEARS. SCIENTISTS AT STELLENBOSCH UNIVERSITY’S (SU) SCHOOL FOR CLIMATE STUDIES HOPE TO PROVIDE NEW INSIGHT INTO THE CURRENT VULNERABILITY OF THE LAST REMAINING PENGUIN SPECIES IN AFRICA. THE STUDY, TITLED “A NATURAL TERMINAL PLEISTOCENE DECLINE OF AFRICAN PENGUIN POPULATIONS ENHANCES THEIR ANTHROPOGENIC EXTINCTION RISK” WAS PUBLISHED IN THE AFRICAN JOURNAL OF MARINE SCIENCE ON 20 APRIL 2023. view more 

CREDIT: INFOGRAPHIC: JENNY FROST

Imagine the view from the western coastline of southern Africa during the Last Glacial Maximum (LGM) over twenty thousand years ago: in the distance you would see at least fifteen large islands – the largest 300 square kilometres in area – swarming with hundreds of millions of marine birds and penguin colonies.

Now imagine sea levels rising up to a hundred metres between fifteen to seven thousand years ago, gradually covering these large islands until only small hill tops and outcrops remained above water. Over the past 22 000 years this resulted in a tenfold reduction in suitable nesting habitat for African penguins, sending their population numbers into steep decline.

This is the paleo-historical picture of the geographical range of African penguins, created by scientists in the evolutionary genomics research group in the Department of Botany and Zoology and the School for Climate Studies at Stellenbosch University (SU). With this effort, they hope to provide new insight into the current vulnerability of the last remaining penguin species in Africa.

The study, titled “A natural terminal Pleistocene decline of African penguin populations enhances their anthropogenic extinction risk” was published in the African Journal of Marine Science on 20 April 2023.

Dr Heath Beckett, first author of the article and postdoctoral fellow at SU’s School for Climate Studies, says this paleo-historical image of multiple millions stands in stark contrast to the current reality of a post-1900 collapse of the African penguin population.

In 1910, Dassen Island (an island off the West Coast, about three square kilometres in area) was teeming with an estimated 1.45 million penguins. However, by 2011 South Africa’s entire African penguin population collapsed to 21 000 breeding pairs, and by 2019 they further declined to only 13 600. Approximately 97% of the current population in South Africa is supported by only seven breeding colonies.

In May 2005 the International Union for the Conservation of Nature classified the African penguin as endangered.

Paleo-historical estimates of penguin population sizes

So how did the southern and western coastlines of southern Africa look like during the last Ice Age? And what can it tell us about penguin population numbers?

As penguins prefer to breed on islands to escape mainland predators, the researchers used topographic maps of the ocean floor off the coast of southern Africa to identify potential historical islands lying at ten to 130 metres below current sea levels.

For islands to qualify as suitable for penguins they needed to offer protection from land-based predators and had to be surrounded by suitable foraging grounds for sardine and anchovy within a 20 kilometre radius.

Assuming that sea levels were much lower during the last Ice Age, they identified 15 large islands off the West Coast, the largest a 300 km2 island lying 130 metres below the sea surface. Then taking into account rising sea levels over the past 15 000 to 7 000 years, they identified 220 islands which would have provided suitable nesting conditions for penguins, of which 216 are less than one km2 in area, while some are as small as 30 m2, barely more than a rock. 

Today the five largest islands off the West Coast of Southern Africa are Robben Island (~5 km2), Dassen Island (~3 km2), Possession Island (~ 1.8 km2) and Seal Island and Penguin Island (both below 1 km2). Possession, Seal and Penguin Island are all off the coast of Namibia. 

Based on the earliest available population density estimates, they then calculated penguin population estimates based on available island area, assuming that penguins usually nest at most 500 metres from the shore.

Following this approach, they estimate that between 6.4 million and 18.8 million individuals could have occupied the southern Cape waters during the Last Glacial Maximum. Due to rising sea levels, however, 15 000 to seven thousand years ago, the habitat for the African penguins to nest on, went into a steep decline.

According to Dr Beckett, the main objective of the study is to show that there have been major changes in habitat availability over the last 22 000 years: “This could have had a massive effect on penguin populations. These populations are now experiencing additional human pressures on top of this in the form of climate change, habitat destruction and competition for food,” he explains.

Implications for conservation management

While this finding raises grave concerns, the researchers argue that it also highlights the potential for a reserve of resilience in African penguins that may be leveraged for its conservation and management in an uncertain future.

Dr Beckett explains: “Changing sea levels would have necessitated the need for multiple relocations of breeding colonies of African penguins on time-scales of centuries, if not even shorter time-scales, and intense competition for breeding space as island habitat became greatly reduced in size. This historical flexibility of response provides some leeway for conservation managers to make available suitable breeding space, even in mainland sites, as long as appropriate nesting sites are made available”.

According to Prof. Guy Midgley, interim director of SU’s School for Climate Studies and a co-author, this millennial-scale set of selection pressures would have favoured strong colonisation ability in the species: “It’s a total survivor and given half a chance, they will hang on. Island hopping saved it in the past, they know how to do this,” he emphasised.

But even given the chance of relocation, how much more will it take to persist given the rise of modern human pressures? When competing against the commercial fishing industry and humanity in general for the same food source, penguins – and other marine life – may not stand a chance.

Therefore, “for any relocation measures to be successful,” they warn, “sufficient access to marine food resources remain a vital element of a coordinated response to prevent extinction of the species”.

Polar ice sheet melting records have toppled during the past decade

The seven worst years for polar ice sheets melting and losing ice have occurred during the past decade, according to new research, with 2019 being the worst year on record.

Peer-Reviewed Publication

NORTHUMBRIA UNIVERSITY

Ice sheet contribution to global sea level 

IMAGE: GRAPH FROM IMBIE SATELLITE DATA RESEARCH SHOWING THE INCREASING CONTRIBUTION OF ICE SHEETS TO GLOBAL SEA LEVEL FROM 1992 TO 2020. view more 

CREDIT: IMBIE / CPOM AT NORTHUMBRIA UNIVERSITY

The seven worst years for polar ice sheets melting and losing ice have occurred during the past decade, according to new research, with 2019 being the worst year on record.

The melting ice sheets now account for a quarter of all sea level rise – a fivefold increase since the 1990’s – according to IMBIE, an international team of researchers who have combined 50 satellite surveys of Antarctica and Greenland taken between 1992 and 2020.

Their findings are published today in the journal Earth System Science Data.

Global heating is melting the polar ice sheets, driving up sea levels and coastal flooding around our planet. Ice losses from Greenland and Antarctica can now be reliably measured from space by tracking changes in their volume, gravitational pull, or ice flow.

NASA and the European Space Agency (ESA) and awarded funding to the Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) in 2011 to compile the satellite record of polar ice sheet melting. Data collected by the team is widely used by leading organisations, including by the Intergovernmental Panel on Climate Change (IPCC).

In their latest assessment, the IMBIE Team – which is led by Northumbria University’s Centre for Polar Observations and Modelling – have combined 50 satellite surveys of Antarctica and Greenland to determine their rate of ice melting.

They have found that Earth’s polar ice sheets lost 7,560 billion tonnes of ice between 1992 and 2020 – equivalent to an ice cube that would be 20 kilometres in height.

The polar ice sheets have together lost ice in every year of the satellite record, and the seven highest melting years have occurred in the past decade.

The satellite records show that 2019 was the record melting year when the ice sheets lost a staggering 612 billion tonnes of ice.

This loss was driven by an Arctic summer heatwave, which led to record melting from Greenland peaking at 444 billion tonnes that year. Antarctica lost 168 billion tonnes of ice – the sixth highest on record – due to the continued speedup of glaciers in West Antarctica and record melting from the Antarctic Peninsula. The East Antarctic Ice Sheet remained close to a state of balance, as it has throughout the satellite era.

Melting of the polar ice sheets has caused a 21 mm rise in global sea level since 1992, almost two thirds (13.5 mm) of which has originated from Greenland and one third (7.4 mm) from Antarctica.

In the early 1990s, ice sheet melting accounted for only a small fraction (5.6 %) of sea level rise. However, there has been a fivefold increase in melting since then, and they are now responsible for more than a quarter (25.6 %) of all sea level rise. If the ice sheets continue to lose mass at this pace, the IPCC predicts that they will contribute between 148 and 272 mm to global mean-sea level by the end of the century.

Professor Andrew Shepherd, Head of the Department of Geography and Environmental Sciences at Northumbria University and founder of IMBIE, said: “After a decade of work we are finally at the stage where we can continuously update our assessments of ice sheet mass balance as there are enough satellites in space monitoring them, which means that people can make use of our findings immediately.”

Dr Inès Otosaka from the University of Leeds, who led the study, said: “Ice losses from Greenland and Antarctica have rapidly increased over the satellite record and are now a major contributor to sea level rise. Continuously monitoring the ice sheets is critical to predict their future behaviour in a warming world and adapt for the associated risks that coastal communities around the world will face.”

This is now the third assessment of ice loss produced by the IMBIE team, due to continued cooperation between the space agencies and the scientific community. The first and second assessments were published in 2012 and 2018/19.

Over the past few years, ESA and NASA have made a dedicated effort to launch new satellite missions capable of monitoring the polar regions. The IMBIE project has taken advantage of these to produce more regular updates, and, for the first time, it is now possible to chart polar ice sheet losses every year.

This third assessment from the IMBIE Team, funded by the ESA and NASA, involved a team of 68 polar scientists from 41 international organisations using measurements from 17 satellite missions, including for the first time from the GRACE-FO gravity mission.  Importantly, it brings the records of ice loss from Antarctica and Greenland in line, using the same methods and covering the same period in time. The assessment will now be updated annually to make sure that the scientific community has the very latest estimates of polar ice losses.

Dr Diego Fernandez, Head of Research and Development at ESA, said: “This is another milestone in the IMBIE initiative and represent an example of how scientists can coordinate efforts to assess the evolution of ice sheets from space offering unique and timely information on the magnitude and onset of changes.

“The new annual assessments represent a step forward in the way IMBIE will help to monitor these critical regions, where variations have reached a scale where abrupt changes can no longer be excluded.”

The study, Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020, is published in the journal Earth System Science Data, and the new dataset is publicly available on the British Antarctic Survey website.

  

Areas in red highlight the zones of cumulative change in ice sheet thickness in Greenland, between 1993-2019

CREDIT

IMBIE / CPOM at Northumbria University

A new study finds that pregnancy affects bats' sensing capabilities

Bats get “pregnancy brain” too

Peer-Reviewed Publication

TEL-AVIV UNIVERSITY

Mother bat holding baby bat. 

IMAGE: MOTHER BAT HOLDING BABY BAT. view more 

CREDIT: YUVAL BARKAI

There have been several studies pointing to an impairment of the cognitive abilities of pregnant women. A new Tel Aviv University study reveals that bats, too, experience a decline in their ability to hunt and orient in space during pregnancy. This impairment stems from the fact that they produce about 20 percent fewer calls, the sounds that allow them to orient themselves using echolocation, on top of flying at a slower pace and at a lower altitude. The researchers highlight the fact that, to the best of their knowledge, this is the first evidence of pregnancy affecting mammals’ sensory abilities.

The study was led by Mor Taub, a research assistant in the laboratory of Prof. Yossi Yovel, head of Tel Aviv University’s Sagol School of Neuroscience and faculty member of the School of Zoology, Wise Faculty of Life Sciences. The study’s findings were published in the journal BMC Biology.

Mor Taub explains: “At the peak of pregnancy, bats carry about 20 percent more than their normal body weight, and it is clear that this excess weight impacts their flying capacity. In this study, we wanted to check whether and to what extent pregnancy affects bats’ echolocation ability, their sonar. Bats’ sonar is based on the emitting and receiving of strong and frequent sounds in order to map their surroundings. To make these sounds, bats, like us humans, need to transfer high-pressure air from the lungs through the vocal cords, or vocal membranes, which involves many muscles, such as the chest and diaphragm. We wanted to see if the excess weight from pregnancy affects the production of sounds.”

To this end, Prof. Yovel and his colleagues taught bats to search for and land on a small landing pad in a flight room in the bat laboratory at Tel Aviv University’s Garden for Zoological Research. They recorded the echolocation of two groups: pregnant bats and non-pregnant bats. The researchers found that the rate at which the pregnant bats emitted sounds was significantly lower than that of the control group, with 20 percent greater intervals between each sound.

Prof. Yovel: “Bats change the rate of the sounds they make in accordance with the level of difficulty of the task. The average rate is about 10 calls per second, but when the bat lands, this rate can increase to 100 calls per second. The pregnant bats produced sounds at a rate of only about seven per second, and flew a little slower and lower. Obviously, this slowing down is likely to affect their hunting. When a bat makes fewer calls, it gathers less information about the environment, its chance of colliding with objects increases, and its chance of finding food decreases — and this is at a time when the bat needs extra food to sustain the fetus in its womb. In the second phase of the study, we used a computer simulation to simulate the effect of the decreased rate of calls on the bats’ performance, and indeed, we saw that the slowed rate makes it more difficult for the bats to locate prey.”

The bats in the experiment were of the Kuhl's pipistrelle species, tiny bats that weigh only about six grams (when they are not pregnant). These bats are very common in Israel, and feed mainly on mosquitoes. Despite their weight, bats can live for decades, and their pregnancies are therefore also relatively long, lasting about four months. Previous studies conducted on other species of bats have shown that during pregnancy, bats tend to change their diets. To date, the assumption was that this change in diet was due to the bats’ difficulty in flying, but the current study raises the possibility that the change may also be due to their sensory difficulty in detecting certain types of prey.

“This is the only evidence we found in the professional literature showing that pregnancy affects mammals’ sensory abilities,” says Mor Taub. “We assume that there are similar cases in other species as well, but this is the first time that researchers have been able to measure and demonstrate the impairment empirically. Beyond the scientific interest, it is important to preserve mammal species in the wild, especially during pregnancy and newborn care, since animals are particularly vulnerable during this period.”

Mother bat holding baby bat.

CREDIT

Yuval Barkai

Link to the article:

http://www.yossiyovel.com/images/PDF-Files/TaubMazarYovel2023.pdf

Perovskite solar cells protecting the Earth

Peer-Reviewed Publication

POHANG UNIVERSITY OF SCIENCE & TECHNOLOGY (POSTECH)

Last summer, metropolitan areas of Korea including Seoul were hit by an unprecedented heavy rainfall, which inundated various locations. Similarly, torrential downpours engulfed about one-third of Pakistan, leading to widespread flooding. New York State was not spared as it experienced heavy snowstorms in December of last year, with snowfall of more than one meter. 

These events underscore a multitude of extreme weather phenomena that the world is currently grappling with. Last year was the 5th hottest year on record since modern temperature recordkeeping began in 1850 (according to the EU Commission’s climate change monitoring agency). Unfortunately, environmental pollution remains a key driver of extreme weather patterns. The harmful substances in our daily lives and air pollutants released by factory chimneys continue to afflict the Earth. To mitigate this situation, it has become necessary to promote green renewables. This measure can help to reduce carbon emissions and harmful substances, ultimately fostering a more sustainable coexistence between humanity and the planet.

A research team led by Professor Taiho Park, and PhD candidates Dohyun Kim, Hyuntae Choi, and Wooteak Jung from the Department of Chemical Engineering at POSTECH, Dr. Nam Joong Jeon from Korea Research Institute of Chemical Technology (KRICT), and Professor Seulki Song from the Department of Chemical Engineering and Applied Chemistry at Chungnam National University successfully developed novel additives for perovskite film treatment, which have been found to enable the production of  highly efficient and stable perovskite solar cells. The research findings have been published in Energy & Environmental Science, a prestigious journal in the fields of energy and the environment.

The perovskite solar cell (PSC) is a type of solar cell that includes a perovskite-structured compound. Owing to its easy and affordable fabrication process, PSC has garnered significant attention as a next-generation solar cell. However, it is susceptible to moisture and surface defects, which undermines its power conversion efficiency. To improve its stability and efficiency, the removal of surface defects from perovskite film is deemed essential. The conventional approach to surface treatment has involved dissolving the passivating material in a solvent and adding it to the surface. However, this method has presented challenges, such as solvent vapor leading to the solidification of the additive impeding the removal of the surface defects.    

The research team introduced a novel engineering approach for the surface treatment of PSCs, using an additive named alkylammonium formats (AAFos). AAFos comprises a cation and a pseudo-halide anion which remain in a liquid state even at relatively low temperatures due to their weak coordination. The team focused on the phase transition of AAFos from solid to liquid, which facilitated the elimination of defects on the perovskite film surface. After undergoing brief thermal treatment, AAFos transformed from a solid to a liquid state, eliminating the defects on the film surface before solidifying back into a stable state at room temperature. The pseudo-halide anion of AAFos has a higher affinity for halide defects, which results in surface defect passivation while the long alkyl chain of the cation improves moisture stability by preventing moisture permeation into the perovskite layer.

The team’s experimental findings confirm that power conversion efficiency can be increased. With the use of AAFos, the team achieved a power conversion efficiency of 25% from a PSC active area and an impressive fill factor3 of 80.77% in the same PSC module, which is the world’s highest level. Furthermore, in a PSC module with a large active area of 23.75cm2, the efficiency was 20.82%, overcoming the limitations of traditional solar cells where a larger active area typically results in lower efficiency and fill factors.

The development of renewable energy, particularly solar cells, seems to have transitioned from being an option to being a mandate of late. The team’s work holds the potential to position perovskite solar cells as the next generation of solar cells and emphasizes their ability in being utilized over large active areas.

This study was conducted with the support from the National Research Foundation of Korea.

Punctuation in literature of major languages is intriguingly mathematical

Peer-Reviewed Publication

THE HENRYK NIEWODNICZANSKI INSTITUTE OF NUCLEAR PHYSICS POLISH ACADEMY OF SCIENCES

Hazard functions in seven major Western languages 

IMAGE: HAZARD FUNCTIONS REPRESENT THE PROBABILITY OF USING A PUNCTUATION MARK AS A FUNCTION OF THE LENGTH OF THE SEQUENCE WITHOUT THESE MARKS. IN TERMS OF PUNCTUATION, THE MOST ‘CROSS-LINGUISTIC’ IS GERMAN (GREEN CHART). view more 

CREDIT: SOURCE: IFJ PAN

A moment's hesitation... Yes, a full stop here – but shouldn’t there be a comma there? Or would a hyphen be better? Punctuation can be a nuisance; it is often simply neglected. Wrong! The most recent statistical analyses paint a different picture: punctuation seems to “grow out” of the foundations shared by all the (examined) languages, and its features are far from trivial.

To many, punctuation appears as a necessary evil, to be happily ignored whenever possible. Recent analyses of literature written in the world's current major languages require us to alter this opinion. In fact, the same statistical features of punctuation usage patterns have been observed in several hundred works written in seven, mainly Western, languages. Punctuation, all ten representatives of which can be found in the introduction to this text, turns out to be a universal and indispensable complement to the mathematical perfection of every language studied. Such a remarkable conclusion about the role of mere commas, exclamation marks or full stops comes from an article by scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow, published in the journal Chaos, Solitons & Fractals.

“The present analyses are an extension of our earlier results on the multifractal features of sentence length variation in works of world literature. After all, what is sentence length? It is nothing more than the distance to the next specific punctuation mark –  the full stop. So now we have taken all punctuation marks under a statistical magnifying glass, and we have also looked at what happens to punctuation during translation,” says Prof. Stanislaw Drozdz (IFJ PAN, Cracow University of Technology).

Two sets of texts were studied. The main analyses concerning punctuation within each language were carried out on 240 highly popular literary works written in seven major Western languages: English (44), German (34), French (32), Italian (32), Spanish (32), Polish (34) and Russian (32). This particular selection of languages was based on a criterion: the researchers assumed that no fewer than 50 million people should speak the language in question, and that the works written in it should have been awarded no fewer than five Nobel Prizes for Literature. In addition, for the statistical validity of the research results, each book had to contain at least 1,500 word sequences separated by punctuation marks. A separate collection was prepared to observe the stability of punctuation in translation. It contained 14 works, each of which was available in each of the languages studied (two of the 98 language versions, however, were omitted due to their unavailability). In total, authors in both collections included such writers as Conrad, Dickens, Doyle, Hemingway, Kipling, Orwell, Salinger, Woolf, Grass, Kafka, Mann, Nietzsche, Goethe, La Fayette, Dumas, Hugo, Proust, Verne, Eco, Cervantes, Sienkiewicz or Reymont.

The attention of the Cracow researchers was primarily drawn to the statistical distribution of the distance between consecutive punctuation marks. It soon became evident that in all the languages studied, it was best described by one of the precisely defined variants of the Weibull distribution. A curve of this type has a characteristic shape: it grows rapidly at first and then, after reaching a maximum value, descends somewhat more slowly to a certain critical value, below which it reaches zero with small and constantly decreasing dynamics. The Weibull distribution is usually used to describe survival phenomena (e.g. population as a function of age), but also various physical processes, such as increasing fatigue of materials.

“The concordance of the distribution of word sequence lengths between punctuation marks with the functional form of the Weibull distribution was better the more types of punctuation marks we included in the analyses; for all marks the concordance turned out to be almost complete. At the same time, some differences in the distributions are apparent between the different languages, but these merely amount to the selection of slightly different values for the distribution parameters, specific to the language in question. Punctuation thus seems to be an integral part of all the languages studied,” notes Prof. Drozdz, only to add after a moment with some amusement: “...and since the Weibull distribution is concerned with phenomena such as survival, it can be said with not too much tongue-in-cheek that punctuation has in its nature a literally embedded struggle for survival.”

The next stage of the analyses consisted of determining the hazard function. In the case of punctuation, it describes how the conditional probability of success – i.e. the probability of the next punctuation mark – changes if no such mark has yet appeared in the analysed sequence. The results here are clear: the language characterised by the lowest propensity to use punctuation is English, with Spanish not far behind; Slavic languages proved to be the most punctuation-dependent. The hazard function curves for punctuation marks in the six languages studied appeared to follow a similar pattern, they differed mainly in vertical shift.

German proved to be the exception. Its hazard function is the only one that intersects most of the curves constructed for the other languages. German punctuation thus seems to combine the punctuation features of many languages, making it a kind of Esperanto punctuation. The above observation dovetails with the next analysis, which was to see whether the punctuation features of original literary works can be seen in their translations. As expected, the language most faithfully transforming punctuation from the original language to the target language turned out to be German.

In spoken communication, pauses can be justified by human physiology, such as the need to catch one's breath or to take a moment to structure what is to be said next in one's mind. And in written communication?

“Creating a sentence by adding one word after another while ensuring that the message is clear and unambiguous is a bit like tightening the string of a bow: it is easy at first, but becomes more demanding with each passing moment. If there are no ordering elements in the text (and this is the role of punctuation), the difficulty of interpretation increases as the string of words lengthens. A bow that is too tight can break, and a sentence that is too long can become unintelligible. Therefore, the author is faced with the necessity of 'freeing the arrow', i.e. closing a passage of text with some sort of punctuation mark. This observation applies to all the languages analysed, so we are dealing with what could be called a linguistic law,” states Dr Tomasz Stanisz (IFJ PAN), first author of the article in question.

Finally, it is worth noting that the invention of punctuation is relatively recent – punctuation marks did not occur at all in old texts. The emergence of optimal punctuation patterns in modern written languages can therefore be interpreted as the result of their evolutionary advancement. However, the excessive need for punctuation is not necessarily a sign of such sophistication. English and Spanish, contemporarily the most universal languages, appear, in the light of the above studies, to be less strict about the frequency of punctuation use. It is likely that these languages are so formalised in terms of sentence construction that there is less room for ambiguity that would need to be resolved with punctuation marks.

The Henryk Niewodniczański Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Kraków Research Consortium: "Matter-Energy-Future", which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. As a result of the categorization of the Ministry of Education and Science, the Institute has been classified into the A+ category (the highest scientific category in Poland) in the field of physical sciences.

SCIENTIFIC PUBLICATIONS:

“Universal versus system-specific features of punctuation usage patterns in major Western languages”

T. Stanisz, S. Drożdż, J. Kwapień

Chaos, Solitons & Fractals, 168, 113183, 2023

DOI: https://doi.org/10.1016/j.chaos.2023.113183

LINKS:

http://www.ifj.edu.pl/

The website of the Institute of Nuclear Physics, Polish Academy of Sciences.

http://press.ifj.edu.pl/

Press releases of the Institute of Nuclear Physics, Polish Academy of Sciences.

IMAGES:

IFJ230419b_fot01s.jpg                                 

HR: http://press.ifj.edu.pl/news/2023/04/19/IFJ230419b_fot01.jpg

Hazard functions represent the probability of using a punctuation mark as a function of the length of the sequence without these marks. In terms of punctuation, the most ‘cross-linguistic’ is German (green chart). (Source: IFJ PAN)