Music, it is often said, is a central achievement of Homo sapiens. Rhythms have the power to bring people together, promoting social bonding and unlocking creativity. One of the central aspects of most modern music-making is the sense of cooperativity between musicians: one person will listen to and respond to the musical ideas of another, creating a dynamic and exciting song. However, despite its importance, the science behind this musical coordination is still unclear. How exactly do musicians listen to one another, integrate this information, and use it to alter the music they are playing, all in real time? Alternatively could music be mostly an autonomous, stereotyped affair which only seems to bear the hallmarks of a coordinated activity? Thankfully, science is starting to provide some answers here, thanks to a landmark paper by Eric Fortune and others in Science this month. The paper finds similar musical cooperativity in the duets of songbirds, expanding our understanding of how universal music is; and it also uncovers some of the exciting neural mechanisms through which this coordination is achieved.

Fortune’s research team investigated the cooperative aspects of music using a species of wren in which males and females sing coordinated duets. His research team wanted to determine whether wren duets were the product of a stereotyped, fixed pattern of vocalizations, or alternatively whether each wren could alter its singing in response to the syllables being sung by the other wren. This is fascinating because it might indicate whether the wrens genuinely coordinate their duets, or whether the duets simply appear coordinated but are actually the result of largely fixed individual behaviors. First, the researchers recorded hundreds of hours of wren song in the plain-tailed wren’s natural habitat of Ecuador. They captured many examples of duet singing, but also some examples of males and females singing their own portions of the duet alone, without a companion. In the solo recordings, the wrens left pauses between its syllables where the other wren should sing. However, these pauses were much longer than the intervals between syllables during a true duet; and moreover the pauses varied in length substantially compared with duets, where the pauses were of similar length. These key differences between solo and duet singing indicated that each wren might not have a stereotyped part it replays, but instead might change its song based on what its partner was singing during a real duet. In other words, coordinated music-making may be a real possibility in wrens.

The behavioral observations led the authors to examine the activity of individual neurons in the wren brains. They hoped to determine exactly how coordination happens on a neural level. The idea was this: a part of the wren brain had been identified which seemed to control song production (the HVC nucleus). Individual neurons in this nucleus could either be more responsive to the wren’s own portion of the duet, or to the partner’s portion of the duet, or to the entire duet performed by both individuals. This would provide some indication of whether the HVC nucleus simply produced the wren’s portion of the duet irrespective of what the partner was singing (if neurons responded most strongly to recordings of only the wren’s portion) or whether instead the HVC nucleus coordinated singing with the partner wren to produce a duet (if neurons responded most strongly to recordings of the full duet). 

To this end, the researchers made audio recordings of duets performed by a number of wren pairs. They then captured the pairs and electrically recorded the activity of individual neurons as they played back either the entire duet, or just the male portions or female portions of the duet. They found that the majority of neurons in the HVC nucleus responded most strongly to recordings of the entire duet, even compared to the summed response of the male and female portions. This is strong evidence that individual wrens have intricate neural mechanisms responsible for listening to their partner’s song and using this information to change their own song, with the goal of producing a graceful duet. Also, when the researchers presented birds with male-only or female-only recordings in which the intervals between syllables had been tweaked to be outside the normal range, most neurons showed a decreased response. This is tremendously important since it indicates the wrens may have neural machinery which is very sensitive to the specific temporal progression of a duet. The speed of music, it seems, matters even to wrens.

Despite the fact that most neurons responded most strongly to the full duet, the researchers still found small populations of neurons which responded predominantly to either the female-only or male-only portions of the duet. This makes intuitive sense because the wrens need some way to not only coordinate singing, but also recognize their own portions of the song and their partner’s portions of the song. It’s still unclear how the different subtypes of neurons integrate all of this information to produce a song which can be dynamically altered as the partner sings. One way of solving this would be to map out the connections between areas of the HVC nucleus in order to see how the entire neural network responds to singing of a duet. This would allow researchers to determine how information is integrated to produce the very complicated behavior observed. The authors also hypothesize that counting neurons could keep track of the song’s beat, helping to coordinate behavior. 

Another thought-provoking hypothesis mentioned by the researchers was that perhaps the females ‘led’ the duet. After all, when singing alone, males exhibited more variability in their singing than females and produced segments of lower volume than females. Furthermore, during duet singing, males sometimes missed their syllables, and in response the females lengthened the interval between their syllables and continued singing, possibly to lead the males to sing the right notes. Finally, in both males and females, the female portion of the duet elicited stronger activation of neurons than the male portion. Therefore the wrens not only coordinate singing, but the female may in fact lead the song!

Fortune’s team of researchers discovered some vitally important facts about musical cooperation which may be shown to be applicable in humans as well. It is likely that plain-tailed wrens coordinate their duet singing, responding to each other’s vocalizations on a syllable-by-syllable level rather than simply repeating rote behavior independently of their partner’s vocalizations. The HVC nucleus of the brain contained a majority of neurons which preferentially activated to the duet recording rather than either male-only or female-only recordings, providing some evidence of a neural mechanism for this. And finally, female wrens may in fact lead the duet song. While this may not be directly applicable to cooperative music-making in humans, it provides some terrifically important, elementary insights into how coordination between individuals is vital to music, and how neural circuits might orchestrate this coordination.

Article by Michael Lynn, 4th year BSc. Biology at the University of Ottawa.

Imagine this: you just lost a limb in a workplace accident and are reviewing your options with your doctor. You sit there exhausted, worn out from the pain, half listening to the doctor as they go through the various treatments, when your ears perk up.

“The best option is to go undergo the full regeneration of your lost limb, although it will take quite some time and energy, and it’s kind of experimental-“

Fiction? Currently yes.

In the long term however, many researchers are hoping that their regeneration research ultimately pays off and leads to a scenario such as described above.

In their quest, they’re looking into a vast variety of promising avenues, one of which includes the study of natural analogues of forelimb regeneration to understand its mechanisms and gather inspiration.

The Notophthalmus viridescens, commonly known as the Red-spotted newt, is an amphibious species capable of regenerating a variety of its body parts, i.e. its forelimbs. It is believed to conduct regeneration through the transdifferentiation of differentiated tissue near the site of injury. That is that the differentiated cells near the site of its limb injury will form a blastema of undifferentiated cells, within 3 days of forelimb amputation. The blastema grows until the 15th day of the regeneration process and pushes forward leaving behind undifferentiated cells, which differentiate back into the tissues lost during amputation. Thus cells that may have been skin cells can dedifferentiate and then differentiate into a muscle cell, to a certain extent.

In the laboratory, an in vitro study conducted by two Japanese researchers, Drs. Yamanaka & Takahashi, in 2005 discovered that differentiated cells could be induced to become stem cell-like through the upregulation of four genes – Oct4, Klf4, Sox2, and cMyc. By increasing the expression of these 4 genes, the researchers were able turn differentiated cells such as skin cells, into pluripotent stem cells, that are capable of becoming almost any cell in the body. They termed these cells induced pluripotent stem cells (iPSCs). To call this work ground breaking would be an understatement.

To add to the intrigue, recent work in 2009 by Dr. Panagiotis Tsonis has shown that the upregulation of the 4 stem cell pluripotent genes identified by Drs Yamanaka & Takahashi, does in fact seem to occur during the newt’s regeneration process. This finding seems to explain how differentiated cells near the site of a newt’s injury can become undifferentiated stem cell-like cells, as basically the newt is naturally inducing pluripotency in these cells! However, Dr. Tsonis’ data offers only one facet to newt regeneration. He determined his finding by analyzing the mRNA content of the regenerating tissue ends of amputated newt forelimbs. mRNA, known as messenger RNA, is a molecule in cells that helps encode proteins. It is encoded from the DNA inside the nucleus of a cell. Thus, determining its relative quantity should give an idea as to how much a certain gene is expressing. However, Dr. Tsonis’ data does not indicate where and in which cells the iPSC genes are being upregulated. This additional data would be important, as currently it seems like there is upregulation of the 4 iPSC genes, but there are multiple different cell types in the tissue samples that Dr. Tsonis used, including the undifferentiated cells of the blastema. One can guess that it is the cells undifferentiating into the blastema cells, that have regulation, but of course this must be confirmed, especially since a 2009 paper in Nature seems to indicate that the blastema itself is not a mass of homogeneous mass of induced-pluripotent stem cells. In the paper, Kragl et al. suggest that in axolotl salamander regeneration, certain cells of the blastema are able to ‘remember’ their origins and thus favour differentiating into a certain type of cell over others. This makes sense, as otherwise the blastema at the tip of a limb may regenerate into a tail!

Ultimately, all of this research is done in the hope that it can be eventually applied to humans. There are many obstacles to this; one being that of the 4 iPSC genes, cMyc and Klf4 are related to cancer. By trying to convert differentiated cells into pluripotent stem cells, one could instead turn them into tumour cells. Researchers have been investigating the link between induced pluripotency and tumours closely. A 2010 paper  in Cell: Stem Cell found that if one was to inactivate a tumour suppressor gene (Arf) that exists in mammals but not newts, along with another gene that exists in both, it is possible to make mammalian muscle re-enter the cell cycle. In fact, Yamanaka’s aforementioned groundbreaking paper tested whether they were able to induce pluripotency in their adult cells by seeding them into the different layers of a developing mouse embryo, and then determining whether the seeded cells turned in tumours. If they did, they were determined to have been induced into pluripotency. In spite of these problems, there has been tremendous progress in the field of induced pluripotent stem cell research. It’s still a field in its infancy, but ultimately the goal is no less smaller than the regeneration of lose limbs and organs of people everywhere, and thus the regeneration of their quality of life.

Article by Saad Ahmed, who is currently completing his 4th year of a BSc. Biochemistry degree.

The International Agency for Research on Cancer (IARC) recently reported that excessive cell phone use could “possibly cause cancer.” There has been significant debate about the implications of the report. As the Globe and Mail reports, much of the debate has been characterized by misinformation caused by a lack of scientific literacy. The cancer risk associated with excess cell phone use remains minimal because the radiation it emits is non-ionizing. Specifically, when it comes to cancer causing agents, we should be most concerned about ionizing forms of radiation that cause cellular damage.

While the potential risks associated with cell phone use should be taken seriously, increased science research relating to this matter is of vital importance so that the average citizen understands the tangible risk associated with his/her behaviour.

The incidence of skin cancer, for example, continues to increase. It is proven that excessive exposure to the sun can cause cancer because its rays carry both non-ionizing and ionizing radiation. Nonetheless, we continue to expose ourselves to unhealthy amounts of sun at alarming rates.

Headlines that connect cell phone use with cancer are understandably disconcerting, given the amount of time that most of us spend on our cell phones. Be that as it may, for the time being, scientifically speaking there’s more to fear about the sun than cell phones.

superiorvintage:

26 June 2011 by Andy Coghlan

They may not have verbs, nouns or past participles, but birds challenge the notion that humans alone have evolved grammatical rules.

Bengal finches have their own versions of such rules – known as syntax – says Kentaro Abe of Kyoto University, Japan. “Songbirds have a spontaneous ability to process syntactic structures in their songs,” he says.

To show a sense of syntax in the animals, Abe’s team played jumbled “ungrammatical” remixes of finch songs to the birds and measured the response calls.

Although many animals, including dogs, parrots and apes are known to interpret and construct “sentences”, and recognise human words for individual objects, Abe says that only his finches have been shown to have a form of grammar in their utterances. Similar claims have been made for whale song, however.

In the wild, Bengal finches call back vigorously whenever they hear unfamiliar songs, usually from intruding finches. In the lab, Abe and colleague Dai Watanabe of the Japan Science and Technology Agency in Saitama exploited these reactions to gauge whether finches could notice “ungrammatical” songs.

Read More

PART 2: INTERVIEWING FOR A LAB POSITION

By now, you’ve sent out multiple emails to various primary investigators (PI), waited several business days for responses, and (congratulations) received an invitation for an interview with your potential new boss.

LAB INTERVIEW FREQUENTLY ASKED QUESTIONS:

1.      When and how should I reply to the interview offer email?

Reply as soon as possible or within 24h. PIs look for ENTHUSIASM in inexperienced students. Promptly responding to their emails establishes your interest in their research and suggests to them that you will be a motivated employee.

2.      When should I schedule an interview?

Once again, earlier is better. If the PI has not already provided a date, time, and place, list your general availabilities (“Thursday afternoon”) and allow them to set the time in their subsequent message. Be sure to find their office on a campus map prior to your interview date, or arrive early to find their lab/office.

3.      How should I prepare for the interview?

It is extremely unlikely that the interviewing PI will treat your interview as a comprehensive exam (more info here), but it is a wise idea to search the PI’s publication record (http://pubmed.com). Reading complete articles is unnecessary; however, you should familiarize yourself with several of the recent abstracts. You should also check the impact factor of the journals the lab has published in. Higher impact factor  = more prestige. 

4.      What should I bring with me to the interview?

Other than ENTHUSIASM, you may want to bring a copy of your CV and courses for reference. Also, you may want to bring a notepad to jot down what kind of equipment they have, protocols they use, animal models, lab working hours (ie. flexible vs. 9 to 5) workspace, number of lab members etc.

 As you are interviewed by more PIs and tour more lab spaces, you will get a better sense of what kind of lab you would like to do research in. Interview with a couple of professors before you make an informed decision.

 If you have not received any interview offers, keep emailing others. You’ll find a position somewhere with the >100 scientists affiliated with University of Ottawa

Ariana Noel is a biochemistry master’s student, recipient of NSERC CGS-M and OGS, and a teaching assistant at the University of Ottawa studying the effect of diet on the development of type 1 diabetes.

 You can follow her at http://twitter.com/jariananoel

 In the wake of the global economic crises, rising food and fuel prices, dwindling natural resources, and a growing ecological crisis, many people are rightfully wondering whether our current way of life is sustainable. Amongst the countless proposals for reform, some go even further and advocate radical proposals at the roots of our social, political and economic institutions.

At first glance then, linking the laws of thermodynamics to economics seems like an odd interdisciplinary exercise. Indeed, when first presented on by the Nobel-laureate and chemist Frederick Sody in the 1920s, it was rejected outright, and Soddy was dismissed as a ‘crank.’ Yet Soddy was getting at something that was ahead of its time. He was worried about the sustainability of our current way of life, and he was worried that our economic institutions do not reflect that fact. More so he was worried that the ways our institutions are setup do not reflect scientific principles. Half a century later, a Romanian-born American economist, Nicholas Georgescu-Roegen, revived Soddy’s ideas when he argued the human economy must be considered as a part of the ‘natural economy’. This means that the human institution of exchange, often called, ‘The Economy,’ is a component of planet Earth. As such, The Economy exchanges matter and energy with Earth, which itself has countless exchanges going on in the form of chemical reactions.

Thermodynamically, the human economy can be approximated as an open system, as it exchanges matter and energy with Earth. Our planet can be considered a closed system, as it exchanges energy in the form of solar radiation but not matter. Thus, Georgescu-Reogen argued that current economic models had it all wrong when they treated the human economy separately from the planet’s economy. He continued by restating the second law of thermodynamics, which states that entropy of the universe is constantly increasing, and thus the supply of usable energy is constantly diminishing. For Georgescu-Roegen, this meant that in a closed system such as Earth, the supply of useful energy and matter was constantly diminishing, and the human economy needed to be brought to a state where it could be supported only by organic agriculture. His first policy prescription was the steady reduction of the human population via decreasing growth rates. Even with such measures, Georgescu-Roegen was pessimistic about the future of humanity, and believed that the ultimate heat death of the universe meant that there was really no hope. Such ideas could be described as radical at best, and economists have roundly criticized his assertion that economic ‘degrowth’ could solve our problems.

The problems in Georgescu-Roegen’s approach were many; however the main problem was rooted in his logic linking the second of law of thermodynamics to economics. It is understandable that that the supply of energy is constantly diminishing in the universe, but what does that have to do with the planet Earth? Earth is constantly showered with solar radiation, a constant supply of renewable energy. Furthermore, the entropy of the universe also increases due to chemical reactions in the ‘natural economy,’ such as the very act of living and breathing, as argued by Paik et al in 1980. Finally, the effect of humans on the environment is certainly significant, but the effect of humans on the universe most certainly is miniscule. Georgescu-Roegen’s approach seems to be a mere exercise in pessimism, and although his warning on resource exhaustion should not be taken lightly, they are based off a most obscure, flimsy logic.

These criticisms forced one of Georgescu-Roegen‘s students, Herman Daly, to attempt a more realistic approach in explaining the exchanges between the human and natural economy. Daly is one of the founders of the field of ecological economics, and a leading proponent of the concept of the steady state economy. Unlike Georgescu-Roegen, Daly factors in the solar energy coming to Earth into his economic model and places a lot of hope on technology to solve humanity’s energy needs. Daly argues that orthodox economics assumes that as a resource becomes scarce, the law of supply and demand dictate that its price will rise and consumers will subsequently move to another resource. However, there are certain basic resources that cannot be substituted for, and thus their use should ideally be reduced to the point where the extraction of these resources equals the amount of them that can be recovered. With this idea in mind, a steady-state rate of their use must be established (thus steady state economics!). Like Georgescu-Roegen, Daly argues that the population must be immediately controlled and brought into a steady-state, where deaths equal births. Also like Georgescu-Roegen, he rails against continued economic growth, which he sees as nothing more than “Growthmania”. For Daly, economic development should be the aim – it may be or may not be aligned with the growth of a nation’s GDP. Unlike Georgescu-Roegen however, he considers the fact that technology can go a long way in improving methods of resource extraction and recycling. For Daly, technological improvement is essential to conserving resources as well; however he notes the Jevons paradox, which states that technologies which improve efficiency do not end up conserving but rather increasing consumption. Therefore Daly argues that all the economic changes he proposes must be linked with cultural changes. These ideas link together to form Daly’s conception of the steady-state economy; one in which the economy is neither shrinking nor growing and in which there is a cap-and-trade system on vital resources. This cap-and-trade system would involve the government setting limits on resource extraction, and then issuing permits to users who can choose to use or sell them.

Daly also admits that resource recycling is not completely efficient, and that the supplies of vital resources will continuously dwindle, prompting the need to reach another steady state where the population is lower. Nevertheless, Daly still does use the law of thermodynamics as his justification for his economic principles. His recommendations to prevent irrevocable environmental damage are certainly valid and mirror the opinions of many environmental groups. However, questions still remain as to the validity of trying to link economics and thermodynamics. In the big picture, Daly’s ideas do make sense and much is to be appreciated in how he has re-opened the debate on whether unhindered economic growth is feasible; however the technical details rely on Georgescu-Roegen’s foundations, which are unfortunately obscure.

This post was penned by Saad Ahmed, who is currently completing a BSc Hon. Biochem degree.