Post List

Biology posts

(Modify Search »)

  • June 12, 2015
  • 04:39 AM

Infections and cognitive ability

by Paul Whiteley in Questioning Answers

Today I'm serving up the study findings reported by Michael Benrós and colleagues [1] (open-access) describing how: "Independent of a wide range of possible confounders, significant associations between infections and cognitive ability were observed" in their study of over 160,000 male conscripts during the years 2006–2012 who were tested for cognitive ability. Some further write-up of the study can also be found here.Using the Danish Conscription Registry (existing as a result of Denmark retaining mandatory military service) as a starting point, researchers questioned whether in amongst the growing research base suggesting that "infections and immune responses can affect the brain and activate immunocompetent cells within the brain" there may be something to be had linking infection history and general cognitive ability. Because various connected health registers exist within the Danish healthcare and social systems, researchers were able to link participant cognitive test score results recorded by the Danish Draft Board with infection history as recorded "in the Danish National Hospital Register." Infection history, by the way, was based on a 'recorded' infection not something 'suspected'.The results, taking into account "parental educational level, year of testing, birth order, multiple birth status, birth weight, gestational age, a parental history of infections, parental and individual history of psychiatric disorders and substance abuse" pointed to something of an association between infection history and cognitive test scores. So authors reported to have "found that hospital contacts for infections were associated with lower general cognitive scores at the draft board examination around age 19."The authors are cautious about their results and the requirement for further research investment in this area: "The cognitive ability might be directly affected by infections or related immune responses; however, heritable and environmental factors associated with infections might also influence the associations." That being said, the accompanying media comments from Benrós et al underscore the idea that infection, immune function and cognition might share something of a complicated relationship.A quick glance through the research publication history of members of the authorship team on this paper reveals that this is not the first time that immune system and cognitive / behavioural outcomes have been discussed. I've covered some of this work before on this blog with autoimmune disease as a potential 'risk factor' for mood disorder in mind (see here) again highlighting how the immune system may be doing some much more than responding to foreign invaders. Set against a backdrop of quite a bit of research looking at how infection can and does affect behaviour and cognition (even with autism in mind) I'd be minded to suggest that a greater respect for the role of infection / immune system involvement should filter down into many different areas of medical science in light of the 'game-changing' discoveries being made...To close... in memory of Sir Christopher Lee: Count Dooku was the dog's bollocks...----------[1] Benros ME. et al. The Association between Infections and General Cognitive Ability in Young Men - A Nationwide Study. PLoS One. 2015 May 13;10(5):e0124005.----------Benros ME, Sørensen HJ, Nielsen PR, Nordentoft M, Mortensen PB, & Petersen L (2015). The Association between Infections and General Cognitive Ability in Young Men - A Nationwide Study. PloS one, 10 (5) PMID: 25970427... Read more »

  • June 12, 2015
  • 04:07 AM

A lactate-induced response to hypoxia

by Danielle Stevenson in BHD Research Blog

Hypoxia regulation ensures cell survival and growth in low oxygen environments. HIF signalling is a well-established element of this regulation but is also associated with tumourigenesis in BHD, VHL, HLRCC, TSC, and sporadic cancers. New research from Lee et al., (2015) has identified a second, HIF-independent, hypoxia response which can modify cell survival and growth signalling pathways – the lactate-induced activation of NDRG3-mediated signalling.... Read more »

Lee DC, Sohn HA, Park ZY, Oh S, Kang YK, Lee KM, Kang M, Jang YJ, Yang SJ, Hong YK.... (2015) A lactate-induced response to hypoxia. Cell, 161(3), 595-609. PMID: 25892225  

  • June 11, 2015
  • 03:59 PM

The curious case of Neisseria and the seven-carbon sugar

by Betty Zou in Eat, Read, Science

Neisseria gonorrhoeae releases a seven carbon sugar that activates HIV gene expression and functions as a pathogen associated molecular pattern. Here's the story of how it was discovered and why it could be helping Neisseria evade our immune system.... Read more »

Malott, R., Keller, B., Gaudet, R., McCaw, S., Lai, C., Dobson-Belaire, W., Hobbs, J., St. Michael, F., Cox, A., Moraes, T.... (2013) Neisseria gonorrhoeae-derived heptose elicits an innate immune response and drives HIV-1 expression. Proceedings of the National Academy of Sciences, 110(25), 10234-10239. DOI: 10.1073/pnas.1303738110  

Ryan G. Gaudet,, Anna Sintsova,, Carolyn M. Buckwalter,, Nelly Leung,, Alan Cochrane,, Jianjun Li,, Andrew D. Cox,, Jason Moffat,, & Scott D. Gray-Owen. (2015) Cytosolic detection of the bacterial metabolite HBP activates TIFA-dependent innate immunity . Science, 1251-1255. info:/10.1126/science.aaa4921

  • June 11, 2015
  • 03:12 PM

Milk proteins may protect against cardiovascular disease

by Dr. Jekyll in Lunatic Laboratories

The Maillard reaction is a chemical reaction between amino acids and reducing sugars that results in browned foods like seared steaks and toasted bread. When proteins and sugars are mixed together and heated, new chemical compounds are formed. Some are responsible for new flavors and some, according to a new study, may protect us against cardiovascular disease.... Read more »

  • June 11, 2015
  • 09:35 AM

What’s the Answer? (pan-genome graphs)

by Mary in OpenHelix

This weeks highlighted discussion is the problem of pan-genome graphs, which are ways to represent the variation we find in genomes instead of a linear reference sequence view. I was really struggling with these concepts until I heard a talk at the #TRICON meeting recently. David Haussler had some really helpful visuals. I don’t have […]... Read more »

Benedict Paten, Adam Novak, & David Haussler. (2014) Mapping to a Reference Genome Structure. arXiv: 1404.5010v1

Nguyen, N., Hickey, G., Zerbino, D., Raney, B., Earl, D., Armstrong, J., Kent, W., Haussler, D., & Paten, B. (2015) Building a Pan-Genome Reference for a Population. Journal of Computational Biology, 22(5), 387-401. DOI: 10.1089/cmb.2014.0146  

  • June 11, 2015
  • 08:58 AM

Active hematopoietic sites in Drosophila Adult

by LolitikaMandal in the Node

Studies in the last decade have established Drosophila as the best invertebrate model to study hematopoiesis. Blood cell development in the fruitfly has been shown to have similarities to that of vertebrates both at the level of its origins and important signaling molecules necessary for their formation and differentiation (Evans et al., 2003). It was believed […]... Read more »

  • June 11, 2015
  • 05:11 AM

Higher vitamin D = reduced risk of depression?

by Paul Whiteley in Questioning Answers

"These results support the hypothesis that higher serum 25(OH)D concentrations protect against depression even after adjustment for a large number of sociodemographic, lifestyle and metabolic factors."That was the conclusion reached by Tuija Jääskeläinen and colleagues [1] who analysed data from several thousands of people (men and women aged between 30 -79 years old) included as part of the Finnish Health 2000 survey. Alongside assaying for serum levels of 25(OH)D - 25-hydroxy vitamin D being the metabolite of choice for measuring how much vitamin D a person has - researchers also collected information on whether or not a diagnosis of depression or anxiety had been reported and looked for any potential connections. Further: "sociodemographic and lifestyle variables as well as indicators of metabolic health" were included in the analyses as potential confounders.The results: "Individuals with higher serum 25(OH)D concentrations showed a reduced risk of depression." Indeed: "Higher serum 25(OH)D concentrations were associated with a lower prevalence of depressive disorder especially among men, younger, divorced and those who had an unhealthy lifestyle or suffered from the metabolic syndrome." Metabolic syndrome, by the way, refers to a combination of clinical findings including diabetes, high blood pressure and obesity and has independently been suggested to be associated with depression [2]. Vitamin D levels have also been mentioned with metabolic syndrome in mind [3].Authors also calculated something called the population attributable fraction (PAF) - "the proportional reduction in population disease or mortality that would occur if exposure to a risk factor were reduced to an alternative ideal exposure scenario" - and estimated that nearly a fifth of cases of depression might be 'reduced' "when serum 25(OH)D concentration was at least 50 nmol/l." I've talked about PAF before on this blog; coincidentally suggesting that a fifth of cases of schizophrenia might not be diagnosed if that old devil Toxoplasma gondii weren't present (see here).Whilst calling for: "Large-scale prospective studies... to confirm this finding" the authors are already aware that there is a sizeable volume of peer-reviewed research suggestive of a connection between vitamin D levels and the presentation of depression. I've covered some of that literature before on this blog (see here) accepting that the label 'depression' covers quite a lot of clinical ground and is, most likely the result of a combination of various 'individual' factors: genetic, biological, psychological and sociological, varying from person to person. I'd also suggest that the concept of resilience might come into play too [4].Regular readers of this blog might already know of my interest in all-things 'the sunshine vitamin' (see here for example) and how this vitamin/hormone seems to be involved in so much more than just avoiding rickets. The body of research looking at vitamin D and depression (even vitamin D and schizophrenia) leads me to ask whether there may be wider implications of the proposed link between vitamin D and behaviour/psychiatry specifically in cases where depression (and/or schizophrenia) may be associated with other labels. I'm of course thinking about autism and how the research on vitamin D and the autism spectrum is increasingly suggesting that there may be more to see (see here). Various types of depression do seem to be over-represented when it comes to autism as per the suggestion of a link between some types of autism and bipolar disorder (see here). One therefore wonders to what extent vitamin D deficiency/insufficiency linked to autism might also be part and parcel of the presentation of this other comorbidity...Oh, and if you're thinking about supplementation (with no medical or clinical advice given or intended) please do be careful [5] (3 million international units is a bit much)...Music: Elastica - Connection.----------[1] Jääskeläinen T. et al. Higher serum 25-hydroxyvitamin D concentrations are related to a reduced risk of depression. Br J Nutr. 2015 May;113(9):1418-26.[2] Dunbar JA. et al. Depression: an important comorbidity with metabolic syndrome in a general population. Diabetes Care. 2008 Dec;31(12):2368-73.[3] Awad AB. et al. Vitamin d and metabolic syndrome risk factors: evidence and mechanisms. Crit Rev Food Sci Nutr. 2012;52(2):103-12.[4] Southwick SM. et al. The psychobiology of depression and resilience to stress: implications for prevention and treatment. Annu Rev Clin Psychol. 2005;1:255-91.----------Jääskeläinen T, Knekt P, Suvisaari J, Männistö S, Partonen T, Sääksjärvi K, Kaartinen NE, Kanerva N, & Lindfors O (2015). Higher serum 25-hydroxyvitamin D concentrations are related to a reduced risk of depression. The British journal of nutrition, 113 (9), 1418-26 PMID: 25989997... Read more »

Jääskeläinen T, Knekt P, Suvisaari J, Männistö S, Partonen T, Sääksjärvi K, Kaartinen NE, Kanerva N, & Lindfors O. (2015) Higher serum 25-hydroxyvitamin D concentrations are related to a reduced risk of depression. The British journal of nutrition, 113(9), 1418-26. PMID: 25989997  

  • June 10, 2015
  • 06:15 PM

New drug can clear all psoriasis symptoms

by Dr. Jekyll in Lunatic Laboratories

Good news for anyone who has psoriasis, a University of Manchester led trial of a new drug has resulted in 40 percent of people showing a complete clearance of psoriatic plaques after 12 weeks of treatment and over 90 percent showing improvement. The research tested 2,500 people with psoriasis. Half were given a new drug – ixekizumab – either once every two or four weeks. The other half were given a placebo or a widely used drug for psoriasis called etanercept.... Read more »

Prof Christopher E M, Griffiths, MD, Prof Kristian Reich, MD, Prof Mark Lebwohl, MD, Prof Peter van de Kerkhof, MD, Prof Carle Paul, MD, Alan Menter, MD, Gregory S Cameron, PhD, Janelle Erickson, PhD, Lu Zhang, MS.... (2015) Comparison of ixekizumab with etanercept or placebo in moderate-to-severe psoriasis (UNCOVER-2 and UNCOVER-3): results from two phase 3 randomised trials . Lancet. DOI:  

  • June 10, 2015
  • 05:44 PM

First functional, synthetic immune organ with controllable antibodies created by engineers

by Dr. Jekyll in Lunatic Laboratories

Cornell University engineers have created a functional, synthetic immune organ that produces antibodies and can be controlled in the lab, completely separate from a living organism. The engineered organ has implications for everything from rapid production of immune therapies to new frontiers in cancer or infectious disease research.... Read more »

Purwada, A., Jaiswal, M., Ahn, H., Nojima, T., Kitamura, D., Gaharwar, A., Cerchietti, L., & Singh, A. (2015) Ex vivo Engineered Immune Organoids for Controlled Germinal Center Reactions. Biomaterials. DOI: 10.1016/j.biomaterials.2015.06.002  

  • June 10, 2015
  • 09:36 AM

Video Tip of the Week: GenomeConnect, the ClinGen piece for patients

by Mary in OpenHelix

GenomeConnect is part of the larger ClinGen effort that I began to discuss last week, but this aspect is specifically a portal for patients who have (or may get) genetic testing results of various types. The ClinGen team will use this interface to capture the testing data–the genotypes, and the health history, or phenotypes, and […]... Read more »

Rehm, H., Berg, J., Brooks, L., Bustamante, C., Evans, J., Landrum, M., Ledbetter, D., Maglott, D., Martin, C., Nussbaum, R.... (2015) ClinGen — The Clinical Genome Resource. New England Journal of Medicine, 2147483647. DOI: 10.1056/NEJMsr1406261  

  • June 10, 2015
  • 08:31 AM

Climate change will affect the distribution and diversity of marine organisms

by Sarah Stephen in An ecological oratorio

Climate change will force marine organisms  towards the poles, but would they be safe there too? Human activities such as emissions from the use of fossil fuels, rampant urbanisation, deforestation, and modern agricultural practices, are all altering the earth’s climate in an unprecedented scale. Climate change not only occurs in the land, but also in water bodies. Studies have indicated that sincethe 1950s, the amount of heat stored in the ocean (ocean heat) has increased considerably. Besides, ocean temperatures have increased throughout the world since the advent of the twentieth century, with the past three decades recording the highest temperatures since the measurements began. A major consequence of increase in ocean temperatures is the corresponding decrease in dissolved oxygen levels. This phenomenon is predicted to significantly disturb marine ecosystems. Recent research by a group of American and German scientists revealed the consequences of oceanic climate change on a range of fish and crustacean species in the North Atlantic with different levels of tolerance towards heat and oxygen levels. The researchers'  climate models predict substantial warming and deoxygenation throughout most of the upper ocean by the end of this century which in turn will affect the distribution  of marine  creatures. Their studies predict that warming of water and oxygen depletion would force the organisms to migrate towards the pole due to deficiency of the original native waters to sustain their energy requirements. The scientists predict that even the waters towards the pole would have reduced oxygen levels meaning the survival of the migrated could be precarious even there. Furthermore, this movement could alter the ecosystems in the polar waters due to many factors including competition from the migrants which may alter species ecologies.References C, Ferrel A, Seibel B, Pörtner HO, & Huey RB (2015). Ecophysiology. Climate change tightens a metabolic constraint on marine habitats. Science (New York, N.Y.), 348 (6239), 1132-5 PMID: 26045435... Read more »

Deutsch C, Ferrel A, Seibel B, Pörtner HO, & Huey RB. (2015) Ecophysiology. Climate change tightens a metabolic constraint on marine habitats. Science (New York, N.Y.), 348(6239), 1132-5. PMID: 26045435  

  • June 10, 2015
  • 08:30 AM

Hay Fever: Maladies, Melodies And Remedies

by Julia van Rensburg in The 'Scope

What the latest research says about allergies and your immune system. ... Read more »

Leb VM, Jahn-Schmid B, Schmetterer KG, Kueng HJ, Haiderer D, Neunkirchner A, Fischer GF, Nissler K, Hartl A, Thalhamer J.... (2008) Molecular and functional analysis of the antigen receptor of Art v 1-specific helper T lymphocytes. The Journal of allergy and clinical immunology, 121(1), 64-71. PMID: 18037161  

Jahn-Schmid B, Hauser M, Wopfner N, Briza P, Berger UE, Asero R, Ebner C, Ferreira F, & Bohle B. (2012) Humoral and cellular cross-reactivity between Amb a 1, the major ragweed pollen allergen, and its mugwort homolog Art v 6. Journal of immunology (Baltimore, Md. : 1950), 188(3), 1559-67. PMID: 22205029  

Wopfner N, Bauer R, Thalhamer J, Ferreira F, & Chapman M. (2008) Immunologic analysis of monoclonal and immunoglobulin E antibody epitopes on natural and recombinant Amb a 1. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 38(1), 219-26. PMID: 18028463  

Asero R, Bellotto E, Ghiani A, Aina R, Villalta D, & Citterio S. (2014) Concomitant sensitization to ragweed and mugwort pollen: who is who in clinical allergy?. Annals of allergy, asthma , 113(3), 307-13. PMID: 25053399  

  • June 10, 2015
  • 08:14 AM

Cortical Microcircuit Assembly: The Migratory Path Matters

by Kate Gao in the Node

By Peng Kate Gao Developmental neuroscience has traditionally focused on understanding the structural assembly of the nervous system. However, recently it has increasingly been recognized that development also plays a key role in orchestrating the functional assembly of neural circuits1. The neocortex, the center of higher functions in the mammalian brain, can be characterized by its stereotypic lamination at […]... Read more »

  • June 10, 2015
  • 08:00 AM

Everybody Is Just A Little Twisted

by Mark Lasbury in As Many Exceptions As Rules

You may have your head on straight, but your brain is still twisted. Everyone’s is. The symmetry of the brain is not absolute and the two halves are shaped differently, this results in your brain torquing (not twerking) inside your skull. The reasons are many, but one is gender: boy brains and girl brains really are different!... Read more »

Maller, J., Anderson, R., Thomson, R., Rosenfeld, J., Daskalakis, Z., & Fitzgerald, P. (2015) Occipital bending (Yakovlevian torque) in bipolar depression. Psychiatry Research: Neuroimaging, 231(1), 8-14. DOI: 10.1016/j.pscychresns.2014.11.008  

Maller, J., Thomson, R., Rosenfeld, J., Anderson, R., Daskalakis, Z., & Fitzgerald, P. (2014) Occipital bending in depression. Brain, 137(6), 1830-1837. DOI: 10.1093/brain/awu072  

Mock, J., Zadina, J., Corey, D., Cohen, J., Lemen, L., & Foundas, A. (2012) Atypical Brain Torque in Boys With Developmental Stuttering. Developmental Neuropsychology, 37(5), 434-452. DOI: 10.1080/87565641.2012.661816  

Witelson, S., Kigar, D., & Harvey, T. (1999) The exceptional brain of Albert Einstein. The Lancet, 353(9170), 2149-2153. DOI: 10.1016/S0140-6736(98)10327-6  

  • June 10, 2015
  • 04:40 AM

Physical exercise for ADHD meta-analysed

by Paul Whiteley in Questioning Answers

In today's short blog post I'd like to bring to your attention the findings reported by Cerrillo-Urbina and colleagues [1] who, upon gathering the available peer-reviewed evidence, suggested that: "short-term aerobic exercise, based on several aerobic intervention formats, seems to be effective for mitigating symptoms such as attention, hyperactivity, impulsivity, anxiety, executive function and social disorders in children with ADHD [attention deficit hyperactivity disorder]."Reviewing and meta-analysing data from 8 randomised-controlled trials, researchers found that aerobic exercise "had a moderate to large effect on core symptoms" including inattention, hyperactivity and impulsivity. Issues with executive functions, such as working memory and planning behaviour processes also seemingly benefit from such physical activity in line with previous discussions on this blog (see here).Although the authors are quite generalised in what activities fall under the category of 'aerobic exercise' they do specifically mention that: "Yoga exercise suggests an improvement in the core symptoms of ADHD." I'm gonna go one stage further and, without making sweeping generalisations to all ADHD (y'know plurality and all that), suggest that the paper by Thomas Woodward [2] (open-access) might invite further investigation on the potentially beneficial role of martial arts training as and when applied to a condition like ADHD.To quote from Woodward: "Benefits from this practice include better overall health and balance, as well as an improved sense of psychological well being. They do not promote aggression and may be used as a treatment modality for youth who are at-risk for violence." That excerpt kinda says it all about how martial arts training might be right for at least some diagnosed with ADHD. I've extolled the virtues of kata training with [some] autism in mind on this blog before (see here) as an important part of quite of few martial arts. The bit about martial arts being potentially useful for those who 'are at-risk of violence' taps into a growing body of research in this area [3] with ADHD in mind. I might also emphasise that when done correctly, martial arts training probably 'does not promote aggression' as many might first believe...Music: Elvis Presley - In the ghetto. Wise words from the King...----------[1] Cerrillo-Urbina AJ. et al. The effects of physical exercise in children with attention deficit hyperactivity disorder: a systematic review and meta-analysis of randomized control trials. Child Care Health Dev. 2015 May 18.[2] Woodward TW. A review of the effects of martial arts practice on health. WMJ. 2009 Feb;108(1):40-3.[3] Koisaari T. et al. Traffic And Criminal Behavior Of Adults With Attention-Deficit/Hyperactivity With A Prospective Follow-Up From Birth To The Age Of 40 Years. Traffic Inj Prev. 2015 Apr 2:0.----------Cerrillo-Urbina AJ, García-Hermoso A, Sánchez-López M, Pardo-Guijarro MJ, Santos Gómez JL, & Martínez-Vizcaíno V (2015). The effects of physical exercise in children with attention deficit hyperactivity disorder: a systematic review and meta-analysis of randomized control trials. Child: care, health and development PMID: 25988743... Read more »

  • June 9, 2015
  • 05:48 PM

Vampire Plants: Sucking Life into the Community

by Melissa Chernick in Science Storiented

I would like to introduce you to the yellow rattle (Rhinanthus minor). This little plant has pretty yellow flowers that belie a dark secret: it is a vampire plant. Okay, technically, it is a hemiparasite. The yellow rattle has green, photosynthetic leaves to make its own food, but its roots latch onto those of nearby plants to steal their water and nutrients. I guess you could say that it hasn’t gone full parasite. So what’s wrong with a little leaching of material from your neighbor? Must be like stealing cable, right? Well, not exactly. Hemiparastitic plants can have impacts that are highly disproportionate to their small size. By stealing water and nutrients, they reduce the host plants’ photosynthetic rate and biomass, making them less competitive in their habitat. When you are less competitive in a highly-competitive environment then you don’t last all that long. But this is looking at it on an individual, plant-by-plant, level. Let’s scale it up a bit.We’ll start by following the logic trail. Hemiparastic plants are widespread in ecosystems such as meadows where they attach to dominant grasses (in this case, dominant meaning numbers). As individual grass plants are weakened or killed, overall grass biomass decreases. When the dominants are gone there is more room for other types of plants to move in, increasing species richness. More types of plants attract more primary consumers (like insects) to feed on them. More insects attract more secondary consumers, and on and on. All in all that one little plant has caused indirect community level changes. A new paper by Hartley et al. in Ecology looks at how this one little plant can affect multiple trophic levels (or levels in the food chain).The researchers laid out 13 blocks, each containing four 1 by 1 meter plots, in a field site in Sussex, UK. Three out of those four plots were allowed to be naturally colonized by yellow rattle. These “infected plots” were then randomly assigned to one of three treatments: yellow rattle removed, present, or enhanced. Then, during maximum vegetation and invertebrate abundance, plots were censused. Counts, ground cover, vegetation height, and species richness were measured for plants. Invertebrates were sampled with a Vortis suction sampler (a.k.a. bug vacuum) and hand counts. They were identified and classified into their trophic levels: herbivore, predator and detritivore.They found that the density of yellow rattle had pronounced effects on the plant community. Grass cover was lower, plant diversity higher (although not richness), and plant height lower in plots where the hemiparasite was present or enhanced. Going up a trophic level, sap-feeding insects (Hemiptera) increased by 130%, caterpillars (Lepidoptera) by 217% and weevils (Curculionidae) by 188%. Whoa! Going up another level to the predators, spiders and harvestmen (Araneae and Opiliones) increased by 142% and bees and wasps (Hymenoptera) by 180%. Continuing with the whoa! Going down to the detritivore groups, wood lice (Isopoda) went up by 116% and springtails (Arthropleona) by 58%. Of course, not all animals fit into a single trophic group, but as you probably guessed by the trend you’ve been seeing, those groups went up too. Slugs and snails (Gastropoda) by 103% and mites (Acari) by 57%. That’s quite a list, but not everything increased. There were some non-significant groups including flies (Diptera), rove beetles (Staphylinidae), and springtails (Neelipleona and Symphypleona). It is also important to note that these numbers are from enhanced compared to removed plots. The present plots had increases in many of the same categories, though not as dramatic.In scientist-speak these results showed that “the manipulation of a single sub-dominant plant species causes substantial changes in the abundance and diversity of organisms across four trophic levels in individual plots in a complex grassland community.” Basically, they demonstrated that grasses went down and just about everything else went up just by the addition of one, small and less numerous hemiparasite. This one little plant species caused striking (their term), rapid changes in the community. The less obvious effects of yellow rattle were how the effect was actually occurring. Was it on plant community composition or plant quality or stand height? The authors cite a greenhouse study that showed insects to prefer parasitized to unparasitized grasses when given the choice. Add to that that it is known that parasitic plants impact nutrient cycling, especially enhancing the nitrogen content of vegetation overall. This suggests that it may be plant quality that is the driving mechanism. So the observed, large increase of sap-sucking invertebrates, particularly the Hemiptera, with altered plant quality makes sense as does the increase in detritivores with newly nutrient-rich litter. At this point, perhaps you have considered the impact of these plant-attacking invertebrates as well. Good on you. They are probably themselves doing some damage on and affecting change on the plant community, but this work doesn’t go into that. Time for another study I think!Hartley, S., Green, J., Massey, F., Press, M., Stewart, A., & John, E. (2015). Hemiparasitic plant impacts animal and plant communities across four trophic levels Ecology DOI: 10.1890/14-1244.1(image via Urban Butterfly Garden UK)... Read more »

  • June 9, 2015
  • 03:44 PM

Cobalt speeds us up and slows us down

by Rosin Cerate in Rosin Cerate

Cobalt is a relatively hard and brittle metal that can be used to make fancy magnets and is typically found along with copper and nickel in the Earth's crust. It's silver-white in appearance, but when combined with aluminum and oxygen it forms pretty blue compounds such as cobalt blue. Owing to its various effects on the human body, our lives can intersect with cobalt in many ways. One of the things the metal or molecules that contain it tend to do is alter our mobility, speeding us up or slowing us down.Blood dopingCobalt salts such as cobalt chloride can apparently be used to boost athletic performance. When dissolved into our body liquids, cobalt ions activate a molecular pathway that is otherwise turned on when our tissues aren't getting enough oxygen (i.e. hypoxia). This pathway leads to increased production of the protein erythropoietin (EPO), which in turn acts to increase the number of red blood cells available to move oxygen around our bodies (erythropoiesis). So cobalt essentially tricks our body into making more red blood cells. While cobalt salts have been explored as a means of treating anemia (not having enough red blood cells), it appears that some athletes and horse trainers are using it to try and gain an advantage. The deliberate enhancement of red blood cell numbers for purposes other than healing is known as blood doping. This can facilitate things like running really fast or far by ensuring there is more oxygen to support the involved muscles. As it hasn't been well studied, it's not clear exactly how much of an impact cobalt has on athletic performance. Nevertheless, cobalt salts are cheap, easy to acquire, and don't need to be injected, so their non-medical use is expected to continue.Eclipse, an 18th century racehorse who probably wasn't fed cobalt (Source)Vitamin B12Vitamin B12 actually refers to a group of similar molecules that contain a central cobalt atom within a structure that can only be synthesized by microorganisms. Consequently, we are dependent on certain foods (animal-derived or fermented) as a source of this vitamin. In the event that we don’t eat enough of these foods and/or our gastrointestinal tract gets messed up and can’t absorb the vitamin efficiently from the food we eat, a deficiency can result. One of the important things that vitamin B12 does is enable a component of DNA synthesis, which is necessary for cell replication. A deficiency in the cobalt-bearing vitamin can result in adverse effects including extreme fatigue due to anemia and weakness due to peripheral neuropathy, both of which can slow a person down.HerpesDoxovir is a cobalt-containing antiviral drug currently being evaluated as a means of treating infection with the herpes simplex virus 1, the main cause of cold sores. The cobalt core of the drug molecule is thought to be able to interact with proteins used by the virus to get into cells, disrupting this process. While painful mouth ulcers don't exactly limit mobility, I'm guessing they might curtail your desire to talk. Maybe treating the ulcers with a cobalt-containing drug could speed up someone's speech?Hip implantsOne of the options for treating someone with a damaged hip joint that is slowing them down is to replace it with artificial parts. This often involves taking out the upper part of the femur (thigh bone) as well as the section of the pelvis (hip bone) it fits into, and then installing replacements. Various material types are used to make the replacement parts, one of which is metal alloys that consist of cobalt, chromium, and molybdenum. Metal implants are favoured because of their resistance to corrosion and wear. However, if both parts of the joint are made of metal, wear over time can result in small bits breaking off as the metal parts rub against each other. This can lead to toxicity due to increased dissolved metal concentrations in the body.Hip joint replaced with an artificial implant (Source)RadiotherapyOne of the radioactive isotopes of cobalt, Co-60, is really good at producing gamma rays. This ability has been harnessed in the treatment of cancer by radiotherapy (zapping cancer cells with radiation to kill them). One of the common symptoms associated with this therapy is fatigue, so it's another way that cobalt can slow folks down. Cobalt-60 is manufactured by exposing stable cobalt-59 (the most common isotope of the metal) to neutrons in a nuclear reactor. It rose to prominence in the 1950s, as its high activity meant that treatment times were reduced from hours to minutes. Since then, use of cobalt-60 in radiotherapy has declined due to its limited lifespan, the fact that it's still pretty darn radioactive past the point at which it can be used, and its tendency to produce a fine dust that is challenging to provide protection against. It has largely been replaced by linear accelerators that generate super high energy x-rays.Heart damageIn 1965, a brewery in Quebec City decided to add a cobalt salt to their beer. This was done to ensure the beer would foam nicely when it was poured, which had become an issue for breweries at the time due to the foam-killing effects of new detergents used to wash bottles. Unfortunately, the concentration of cobalt in the beer was sufficiently high that heavy drinkers ended up dosing themselves with enough of the metal to cause damage to their hearts. Within the year after the cobalt addition was made, 48 people in Quebec City were found to have serious heart damage, which in many cases resulted in congestive heart failure. The most common symptom was shortness of breath, which of course slows a person down. Similar epidemics of heart toxicity related to cobalt-spiked beer consumption were reported in Belgium, Minnesota, and Nebraska.ReferencesAlexander CS. 1972. Cobalt-beer cardiomyopathy. A clinical and pathologic study of twenty-eight cases. American Journal of Medicine 53(4):395-417.Bernier J, Hall EJ, Giaccia A. 2004. Radiation oncology: a century of achievements. Nature Reviews Cancer 4(9):737-747.Health Quality Ontario. 2006. Metal-on-metal total hip resurfacing arthroplasty: An evidence-based analysis. Ontario Health Technology Assessment Series 6(4):1-57. [Full text]Heffern MC, Yamamoto N, Holbrook RJ, Eckermann AL, Meade TJ. 2013. Cobalt derivatives as promising therapeutic agents. Current Opinion in Chemical Biology 17(2):189-196. [Full text]Ho EN, Chan GH, Wan TS, Curl P, Riggs CM, Hurley MJ, Sykes D. 2015. Controlling the misuse of cobalt in horses. Drug Testing and Analysis 7(1):21-30.Hofman M, Ryan JL, Figueroa-Moseley CD, Jean-Pierre P, Morrow GR. 2007. Cancer-related fatigue: the scale of the problem. Oncologist 12(Suppl 1):4-10. [Full text]... Read more »

Ho EN, Chan GH, Wan TS, Curl P, Riggs CM, Hurley MJ, & Sykes D. (2015) Controlling the misuse of cobalt in horses. Drug testing and analysis, 7(1), 21-30. PMID: 25256240  

Liao Y, Hoffman E, Wimmer M, Fischer A, Jacobs J, & Marks L. (2013) CoCrMo metal-on-metal hip replacements. Physical chemistry chemical physics, 15(3), 746-56. PMID: 23196425  

  • June 9, 2015
  • 11:42 AM

The human sex ratio at conception and the conception of scientific “facts”

by steven orzack in the Node

Few things interest many people more than sex. For some, this means interest in practices and partners. For others, it means producing a son. There is an ocean of claims about how to do this. A quick Google search reveals claims that a woman can up the odds of a son by taking cough syrup, […]... Read more »

Austad, S. (2015) The human prenatal sex ratio: A major surprise: Fig. 1. Proceedings of the National Academy of Sciences, 112(16), 4839-4840. DOI: 10.1073/pnas.1505165112  

Orzack, S., Stubblefield, J., Akmaev, V., Colls, P., Munné, S., Scholl, T., Steinsaltz, D., & Zuckerman, J. (2015) The human sex ratio from conception to birth. Proceedings of the National Academy of Sciences, 112(16). DOI: 10.1073/pnas.1416546112  

Parkes, A. (1926) The Mammalian Sex-Ratio. Biological Reviews, 2(1), 1-51. DOI: 10.1111/j.1469-185X.1926.tb00600.x  

  • June 9, 2015
  • 11:38 AM

Largest-ever study of parental age and autism finds increased risk with teen moms

by Dr. Jekyll in Lunatic Laboratories

The largest-ever multinational study of parental age and autism risk, funded by Autism Speaks, found increased autism rates among the children of teen moms and among children whose parents have relatively large gaps between their ages. The study also confirmed that older parents are at higher risk of having children with autism. The analysis included more than 5.7 million children in five countries.... Read more »

Sandin, S., Schendel, D., Magnusson, P., Hultman, C., Surén, P., Susser, E., Grønborg, T., Gissler, M., Gunnes, N., Gross, R.... (2015) Autism risk associated with parental age and with increasing difference in age between the parents. Molecular Psychiatry. DOI: 10.1038/mp.2015.70  

  • June 9, 2015
  • 09:39 AM

What Happens When 28,000 Volunteers Are Set Loose in the Virtual Serengeti

by Elizabeth Preston in Inkfish

What's a scientist to do with 1.2 million photos, most of grass but some containing valuable data about endangered animals? Turn the whole thing over to the public, if you're the creators of Snapshot Serengeti. This project caught the attention of tens of thousands of volunteers. Now their work has produced a massive dataset that's already helping scientists in a range of fields.

Most online citizen science involves a degree of tedium—counting craters, tracing kelp mats. But Snapshot ... Read more »

join us!

Do you write about peer-reviewed research in your blog? Use to make it easy for your readers — and others from around the world — to find your serious posts about academic research.

If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.

Register Now

Research Blogging is powered by SMG Technology.

To learn more, visit