Coxsackievirus B3 (CVB3) is a positive strand RNA virus with a non-segmented genome of approx. 7.4 kB in size, encoding a single polyprotein which is cleaved by cellular and viral proteins to generate the non-structural and structural proteins. As discussed in a previous post, following the infection of pancreatic acinar cells with CVB3 autophagosome-like vesicles can be observed in infected cells. Akin to the role of the induction of autophagy in the formation of replication centers following the infection of cells with Corona- or Arterivirus’, the autophagy machinery is required for forming the replication centers whilst at the same time the degradation of autophagosomes containing components of the viral replication complex via fusion with the lysosome and subsequent formation of the autolysosome is inhibited. Indeed, in pancreatic acinar cells infected with CVB3, “megaphagosomes” containing components of the viral replication complex can be observed in the absence of increased autophagic flux.Here the contribution of BPIFB3 silencing in the role of the formation of megaphagosomes is discussed. ... Read more »
Coyne CB, Bozym R, Morosky SA, Hanna SL, Mukherjee A, Tudor M, Kim KS, & Cherry S. (2011) Comparative RNAi screening reveals host factors involved in enterovirus infection of polarized endothelial monolayers. Cell host , 9(1), 70-82. PMID: 21238948
Delorme-Axford E, Morosky S, Bomberger J, Stolz DB, Jackson WT, & Coyne CB. (2014) BPIFB3 regulates autophagy and coxsackievirus B replication through a noncanonical pathway independent of the core initiation machinery. mBio, 5(6). PMID: 25491355
Alirezaei M, Flynn CT, Wood MR, & Whitton JL. (2012) Pancreatic acinar cell-specific autophagy disruption reduces coxsackievirus replication and pathogenesis in vivo. Cell host , 11(3), 298-305. PMID: 22423969
Kemball CC, Alirezaei M, Flynn CT, Wood MR, Harkins S, Kiosses WB, & Whitton JL. (2010) Coxsackievirus infection induces autophagy-like vesicles and megaphagosomes in pancreatic acinar cells in vivo. Journal of virology, 84(23), 12110-24. PMID: 20861268
People with autism have a wide range of symptoms, with no two people sharing the exact type and severity of behaviors. This has made finding a cause (or causes) difficult, leaving pseudoscientists to claim vaccines are the cause as if it were that simple (hint: vaccines do not cause autism). Now a large-scale analysis of hundreds of patients and nearly 1000 genes has started to uncover how diversity among traits can be traced to differences in patients’ genetic mutations.... Read more »
Chang, J., Gilman, S., Chiang, A., Sanders, S., & Vitkup, D. (2014) Genotype to phenotype relationships in autism spectrum disorders. Nature Neuroscience. DOI: 10.1038/nn.3907
Researchers at JHU have demonstrated a prosthetic arm that is controlled completely by the user's thoughts.... Read more »
Collinger, J., Wodlinger, B., Downey, J., Wang, W., Tyler-Kabara, E., Weber, D., McMorland, A., Velliste, M., Boninger, M., & Schwartz, A. (2013) High-performance neuroprosthetic control by an individual with tetraplegia. The Lancet, 381(9866), 557-564. DOI: 10.1016/S0140-6736(12)61816-9
There’s one prestigious honor, the Darwin Award, which is given to people that helped improving the human gene pool. However, nobody is really keen on receiving this noble recognition: Darwin Award winners eliminate themselves (or anyway lose their reproductive abilities) in such stupid ways that ensure there’s an idiot less on Earth.... Read more »
Lendrem BA, Lendrem DW, Gray A, & Isaacs JD. (2014) The Darwin Awards: sex differences in idiotic behaviour. BMJ (Clinical research ed.). PMID: 25500113
I'm a bit of a fan of tryptophan biochemistry on this blog. This quite remarkable aromatic amino acid and it's off-shoot metabolites, which appear to have no end of biological uses, have taken quite a bit of my blogging time down the years. Most recently was the suggestion that a metabolite slotting in between serotonin (5-HT) and melatonin might require quite a bit more investigation when it comes to at least some cases of autism (see here).See ya later, President Fartfeathers.The findings reported by Lilly Schwieler and colleagues  (open-access here) add to the scientific interest and their assertion that: "IL-6 [interleukin-6] induces the KYN [kynurenine] pathway, leading to increased production of the N-methyl-D-aspartate receptor antagonist KYNA [kynurenic acid] in patients with schizophrenia." IL-6 by the way, is a cytokine (chemical messenger of the immune system) which is normally taken to be a pro-inflammatory cytokine (see here). Kynurenine and it's metabolic relations, are yet another set of compounds derived from tryptophan. The kynurenic hypothesis of schizophrenia (see here) hints at some of the research history this compound (and metabolites) has with the condition.The Schwieler paper is open-access but a few pointers might be in order:Looking at a "well-characterized cohort of olanzapine-treated patients with chronic schizophrenia" researchers set about looking at cerebrospinal fluid (CSF) levels of various cytokines compared to a small participant group of asymptomatic controls "free from current signs of psychiatric morbidity or difficulties in social adjustment at the time of sampling".Previously measured levels of "tryptophan metabolites of the KYN pathway" were also included in the study bundle. Researchers also looked at a possible 'interplay' between IL-6 and kynurenic acid in human astrocyte cultures. This involved stimulation of said cultures with IL-6 and measuring KYNA using triple quadrupole mass spectrometry.Results: "The CSF IL-6 concentration was elevated in patients with chronic schizophrenia compared with controls." No real surprises there considering what has been reported previously in this area of schizophrenia research  and the growing idea of inflammation and psychiatry being linked. CSF levels of kynurenine and kynurenic acid were also elevated in the schizophrenia group compared to controls, but no significant differences were noted in the starting material (tryptophan) between the groups. Authors also confirmed that IL-6 did indeed significantly raise levels of kynurenic acid (KYNA) in astrocyte cultures.They conclude that "The increased production of KYNA in fetal human astrocytes following exposure of IL-6 shows that this cytokine is able to induce the activity of the KYN pathway." This process may also pertain to schizophrenia.Aside from the limitations already pointed out by the authors in terms of some analytical issues and the spot sampling methodology employed, I might also point out that whilst participants with schizophrenia were all taking olanzapine (and other meds in some cases), the asymptomatic controls were "free from medication for at least 1 month". Granted olanzapine is not generally thought to directly impact on levels of IL-6 for example  but one can't discount that other, more indirect effects might come into play. Indeed, I'm going to be talking about olanzapine, gut bacteria and weight gain (see here) early in the New Year.I'd like to introduce the paper by Johansson and colleagues  at this point, and their observations related to kynurenic acid and related metabolites in "cultured skin fibroblasts obtained from patients with bipolar disorder, schizophrenia or from healthy control individuals." Looking at cells specifically from participants (with all their biological heterogeneity), they similarly concluded that there was an "increase in ratio between neurotoxic 3-HK [3-hydroxykynurenine] and neuroinhibitory/neuroprotective KYNA following exposure to cytokines" in the bipolar and schizophrenia groups compared to controls. The 3-HK finding might be of even greater interest to schizophrenia given the suggestion of a link with redox modulation  and the idea that oxidative stress might be a factor to the condition .What's more to say on this topic? Well, not much more aside from the fact that there may be a complicated relationship between immune function - immune signalling - and amino acid biochemistry which may very well impinge on presented behaviour. Such links also offer some interesting prospects for potential intervention too...And to some music: Lower Than Atlantis - Here We Go.---------- Schwieler L. et al. Increased levels of IL-6 in the cerebrospinal fluid of patients with chronic schizophrenia - significance for activation of the kynurenine pathway. J Psychiatry Neurosci. 2014 Dec 2;39(6):140126. Kunz M. et al. Serum levels of IL-6, IL-10 and TNF-α in patients with bipolar disorder and schizophrenia: differences in pro- and anti-inflammatory balance. Rev Bras Psiquiatr. 2011 Sep;33(3):268-74. Hori H. et al. Effects of olanzapine on plasma levels of catecholamine metabolites, cytokines, and brain-derived neurotrophic factor in schizophrenic patients. Int Clin Psychopharmacol. 2007 Jan;22(1):21-7. Johansson AS. et al. Activation of kynurenine pathway in ex vivo fibroblasts from patients with bipolar disorder or schizophrenia: cytokine challenge increases production of 3-hydroxykynurenine. J Psychiatr Res. 2013 Nov;47(11):1815-23. Colín-González AL. et al. The Janus faces of 3-hydroxykynurenine: Dual redox modulatory activity and lack of neurotoxicity in the rat striatum. Brain Res. 2014 Nov 17;1589:1-14. Flatow J. et al. Meta-analysis of oxidative stress in schizophrenia. Biol Psychiatry. 2013 Sep 15;74(6):400-9.----------... Read more »
Schwieler L, Larsson MK, Skogh E, Kegel ME, Orhan F, Abdelmoaty S, Finn A, Bhat M, Samuelsson M, Lundberg K.... (2014) Increased levels of IL-6 in the cerebrospinal fluid of patients with chronic schizophrenia - significance for activation of the kynurenine pathway. Journal of psychiatry , 39(6), 140126. PMID: 25455350
Many people are unaware of their mathematics-related abilities, and these abilities have to be considered in their evaluations and life outcomes.
Journal of Personal and Social Psychology
Mathematics is one of the most disliked subjects of students. It is probably due to its logical dealing with the quantity, shape, and arrangements, but interesting part of the life is that many people have no clue about their mathematics-related abilities, i.e. they may think that they are good at math but they are not, and vice versa.
Psychologists from Ohio State University have found that nearly one in three people think that they are good at math but their scores are at the bottom half of an objective test of math. In contrast, nearly one-fifth of people think that they are bad at math but their scores are in the top half of the math objective test.
Mathematics on paperHowever, one thing is important to consider in this regard and that is the real life situations rather than objective math test. People, who think that they are good at math, can show numeric competency that can help them in real-life situations. Moreover, they are good at subjective numeracy, and are more likely to do difficult math tasks as compared to people, who think that they are not good at math.
“This has important implications for everyday life. People who are low in subjective numeracy may not do their taxes on time or they may not make thoughtful choices on their health insurance because they just give up when faced with a lot of numbers, ” said Dr. Ellen Peters, co-author of the paper and a professor of psychology at the university.
Researchers have concluded in the paper that “numeric competencies should be used in a more targeted fashion to understand their multiple mechanisms in people’s evaluations, choices, and life outcomes.”
Peters, E., & Bjalkebring, P. (2014). Multiple Numeric Competencies: When a Number Is Not Just a Number. Journal of Personality and Social Psychology DOI: 10.1037/pspp0000019... Read more »
Peters, E., & Bjalkebring, P. (2014) Multiple Numeric Competencies: When a Number Is Not Just a Number. Journal of Personality and Social Psychology. DOI: 10.1037/pspp0000019
Today is the winter solstice, which means it’s also the sixth anniversary of this blog. On these anniversaries I like to write about archaeoastronomy, which is a very interesting topic and an important one for understanding Chaco and Southwestern prehistory in general. Last year I wrote about some research indicating that in the Rio Grande valley, […]... Read more »
Malville JM, & Munro AM. (2010) Cultural Identity, Continuity, and Astronomy in Chaco Canyon. Archaeoastronomy, 62-81. info:/
Source: Alyssa L. Miller, Flickr.For nearly 9 years, this blog has been harping on the blight of overblown press releases, with posts like:Irresponsible Press Release Gives False Hope to People With Tourette's, OCD, and SchizophreniaPress Release: Press Releases Are PrestidigitationNew research provides fresh evidence that bogus press releases may depend largely on our biological make-upSave Us From Misleading Press Releasesetc.So it was heartening to see a team of UK researchers formally evaluate the content of 462 heath-related press releases issued by leading universities in 2011 (Sumner et al., 2014). They classified three types of exaggerated claims and found that 40% of the press releases contained exaggerated health advice, 33% made causal statements based on correlational results, and 36% extrapolated from animal research to humans. A fine duo of exaggerated health advice and causal statements based on correlational results recently caught my eye. Here's a press release issued by Springer, the company that publishes Cognitive Therapy and Research: Don’t worry, be happy: just go to bed earlierWhen you go to bed, and how long you sleep at a time, might actually make it difficult for you to stop worrying. So say Jacob Nota and Meredith Coles of Binghamton University in the US, who found that people who sleep for shorter periods of time and go to bed very late at night are often overwhelmed with more negative thoughts than those who keep more regular sleeping hours.The PR issues health advice (“just go to bed earlier”) based on correlational data: “people who sleep for shorter periods of time and go to bed very late at night are often overwhelmed with more negative thoughts.” But does staying up late cause you to worry, or do worries keep you awake at night? A survey can't distinguish between the two.The study by Nota and Coles (2014) recruited 100 teenagers (or near-teenagers, mean age = 19.4 + 1.9) from the local undergraduate research pool. They filled out a number of self-report questionnaires that assessed negative affect, sleep quality, chronotype (morning person vs. evening person),1 and aspects of repetitive negative thinking (RNT). RNT is a transdiagnostic construct that encompasses symptoms typical of depression (rumination), anxiety (worry), and obsessive-compulsive disorder (obsessions). Thus, the process of RNT is considered similar across the disorders, but the content may differ. The undergraduates were not clinically evaluated so we don't know if any of them actually had the diagnoses of depression, anxiety, and/or OCD. But one can look at whether the types of symptoms that are endorsed (whether clinically relevant or not) are related to sleep duration and timing. Which is what the authors did.Shorter sleep duration and a later bedtime were indeed associated with more RNT. However, when accounting for levels of negative affect, the sleep variables no longer showed a significant correlation.2 Not a completely overwhelming relationship, then.But as expected, the night owls reported more RNT than the non-night owls. Here's how the findings were interpreted in the Springer press release and conspicuously, by the authors themselves (the study of Sumner et al., 2014 also observed this pattern). Note the exaggerated health advice and causal statements based on correlational results. “Making sure that sleep is obtained during the right time of day may be an inexpensive and easily disseminable intervention for individuals who are bothered by intrusive thoughts,” remarks Nota.The findings also suggest that sleep disruption may be linked to the development of repetitive negative thinking. Nota and Coles therefore believe that it might benefit people who are at risk of developing a disorder characterized by such intrusive thoughts to focus on getting enough sleep.“If further findings support the relation between sleep timing and repetitive negative thinking, this could one day lead to a new avenue for treatment of individuals with internalizing disorders,” adds Coles. “Studying the relation between reductions in sleep duration and psychopathology has already demonstrated that focusing on sleep in the clinic also leads to reductions in symptoms of psychopathology.”As they mentioned, we already know that many psychiatric disorders are associated with problematic sleep, and that improved sleep is helpful in these conditions. Recommending that people suffering with debilitating and uncontrollable intrusive thoughts to “just go to bed earlier” isn't particularly helpful. Not only that, such advice can be downright irritating.Here's a news story from Yahoo that plays up the “sleep reduces worry” causal relationship even more:This Sleep Tweak Could Help You Worry LessCan the time you hit the hay actually influence the types of thoughts you have? Science says yes.Are you a chronic worrier? The hour you’re going to sleep, and how much sleep you’re getting overall, may exacerbate your anxiety, according to a new study published in the journal Cognitive Therapy and Research.The great news here? By tweaking your sleep habits you could actually help yourself worry less. Really. Great! So internal monologues of self-loathing (“I'm a complete failure”, “No one likes me”) and deep anxiety about the future (“My career prospects are dismal”, “I worry about my partner's terrible diagnosis”) can be cured by going to bed earlier!Even if you could forcibly alter your chronotype (and I don't know if this is possible), what do you do when you wake up in the middle of the night haunted by your repetitive negative thoughts?Further ReadingAlexis Delanoir on the RNT paper and much more in Depression And Stress/Mood Disorders: Causes Of Repetitive Negative Thinking And RuminationsScicurious, with an amusingly titled piece: This study of hype in press releases will change journalismFootnotes1 Chronotype was dichotomously classified as evening type vs. moderately morning-type / neither type (not a lot of early birds, I guess). And only 75 students completed questionnaires in this part of the study.2 It's notable that the significance level for these correlations was not corrected for multiple comparisons in the first place.References... Read more »
Nota, J., & Coles, M. (2014) Duration and Timing of Sleep are Associated with Repetitive Negative Thinking. Cognitive Therapy and Research. DOI: 10.1007/s10608-014-9651-7
Sumner, P., Vivian-Griffiths, S., Boivin, J., Williams, A., Venetis, C., Davies, A., Ogden, J., Whelan, L., Hughes, B., Dalton, B.... (2014) The association between exaggeration in health related science news and academic press releases: retrospective observational study. BMJ, 349(dec09 7). DOI: 10.1136/bmj.g7015
Biomarkers in the blood, such as SNTF, are elevated for up to 6 days following a concussion compared with preseason levels. This marker may eventually be developed to determine diagnosis and prognosis after a concussion as well as guiding return-to-play decisions.... Read more »
Siman R, Shahim P, Tegner Y, Blennow K, Zetterberg H, & Smith DH Dr. (2014) Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Post-Concussion Symptoms. Journal of Neurotrauma. PMID: 25419578
Prions, misfolded proteins that wreak havoc on the brain, may have finally met their match. Best known for things like mad cow disease and possibly alzheimer’s disease scientists have had no luck stopping prions, until now. Researchers say that a vaccination they have developed to fight a brain-based, wasting syndrome among deer and other animals may hold promise on two additional fronts: Protecting U.S. livestock from contracting the disease, and preventing similar brain infections in humans.... Read more »
Goñi, F., Mathiason, C., Yim, L., Wong, K., Hayes-Klug, J., Nalls, A., Peyser, D., Estevez, V., Denkers, N., Xu, J.... (2014) Mucosal immunization with an attenuated Salmonella vaccine partially protects white-tailed deer from chronic wasting disease. Vaccine. DOI: 10.1016/j.vaccine.2014.11.035
Yes, I know. Another post on the 'day of rest' but I promise you that this will not become a habit. The reason: the paper by Feiyong Jia and colleagues  published in the premier journal Pediatrics. The authors describe a case report of a young child with autism who is observed to have shown improvement in some of the core symptoms of autism following supplementation with the [sunshine] vitamin/hormone of the hour: vitamin D. Further reporting on the paper can be seen here.Although the paper is interesting - "stressing the importance of clinical assessment of vitamin D3 deficiency and the need for vitamin D3 supplementation in case of deficiency" - and fits in well with my borderline obsession with vitamin D, my interest was piqued because we have actually seen something similar from this research group before . On this and that occasion, 'possibly' reporting on the same "32-month-old boy with ASD [autism spectrum disorder] and vitamin D3 deficiency". I've also discussed the previous Jia paper on this blog before (see here).I'm gonna say little more on this topic aside from reiterating my reiteration(?) on that previous post about Jia et al talking about their description of a single case report and how one has to be very careful about generalising to the very wide and very heterogeneous autism (or autisms). Yes, there may indeed be issues with vitamin D levels / availability when it comes to some people on the autism spectrum  (see here for example) but science is still feeling it's way around this topic and where such a finding might link into the grand scheme of things with a diagnosis of autism spectrum disorder in mind.I'm also minded to bring to your attention two other papers also appearing in the same journal and reporting with vitamin D in mind: Hart and colleagues  detailing more results from the Raine study on what maternal vitamin D levels might mean for offspring outcomes, and McNally and colleagues  (who has some research history with vitamin D in mind) talking about how to correct any deficiency. That all being said bearing in mind my prime [blogging] directive: no medical or clinical advice given or intended.Now, about that Sunday lunch...---------- Jia F. et al. Core Symptoms of Autism Improved After Vitamin D Supplementation. Pediatrics. 2014. December 15. Jia F. et al. Vitamin D Supplementation Improves Autistic Symptoms in a Child with AutismSpectrum Disorder. Asian Case Reports in Pediatrics. 2014; 2: 21-24. Pioggia G. et al. Autism and lack of D3 vitamin: A systematic review. Research in Autism Spectrum Disorders. 2014; 8: 1685-1698. Hart PH. et al. Vitamin D in Fetal Development: Findings From a Birth Cohort Study. Pediatrics. 2014. December 15. McNally JD. et al. Rapid Normalization of Vitamin D Levels: A Meta-Analysis. Pediatrics. 2014. December 15.----------Feiyong Jia, Bing Wang, Ling Shan, Zhida Xu, Wouter G. Staal, & Lin Du (2014). Core Symptoms of Autism Improved After Vitamin D Supplementation Pediatrics : doi: 10.1542/peds.2014-2121... Read more »
Feiyong Jia, Bing Wang, Ling Shan, Zhida Xu, Wouter G. Staal, & Lin Du. (2014) Core Symptoms of Autism Improved After Vitamin D Supplementation. Pediatrics. info:/doi: 10.1542/peds.2014-2121
Electrical gating is a technique commonly used to modulate the carrier density of semiconductor devices. While I see many papers that report on experiments which...
The post Taking sides: Efficent gating of LaAlO3/SrTiO3 appeared first on Spin and Tonic.
... Read more »
Stornaiuolo, D., Gariglio, S., Fête, A., Gabay, M., Li, D., Massarotti, D., & Triscone, J. (2014) Weak localization and spin-orbit interaction in side-gate field effect devices at the LaAlO3/SrTiO3 interface. Physical Review B, 90(23). DOI: 10.1103/PhysRevB.90.235426
Think you know what causes depression? Well unfortunately scientists don’t have the exact answer, surprised? That’s not the only problem, there is an ever growing concern that we live in an over medicated society and a newly released study doesn’t paint a better picture. About 15 percent of women in the United States suffer from anxiety disorders and depression during their pregnancies, and many are prescribed antidepressants. However little is known about how early exposure to these medications might affect their offspring as they mature into adults.... Read more »
Altieri SC, Yang H, O'Brien HJ, Redwine HM, Senturk D, Hensler JG, & Andrews AM. (2014) Perinatal vs. Genetic Programming of Serotonin States Associated with Anxiety. Neuropsychopharmacology. PMID: 25523893
What happens when scientists publish papers that aren't meant to be taken seriously? Is ironic, satirical and joke science all in good fun, or can it be dangerous?
This is the question asked by Drexel University researchers Maryam Ronagh and Lawrence Souder in a new paper is called The Ethics of Ironic Science in Its Search for Spoof.
The British BMJ journal is known for an annual Christmas special issue filled with unusual articles. For example, two years ago they explored the questio... Read more »
Ronagh M, & Souder L. (2014) The Ethics of Ironic Science in Its Search for Spoof. Science and engineering ethics. PMID: 25510233
"The relationship between JH/HDCT [joint hypermobility / heritable disorders of connective tissue] and mental disorders merits further attention in order to improve current knowledge and clarify a possible common etiology."There is nothing in the desert and no man needs nothing.That was the conclusion reached in the paper by Carolina Baeza-Velasco and colleagues  looking at the possibility of some interesting connections, outside of just physical presentation, when it comes to the range of conditions headed under the label 'disorders of connective tissue'. The list of diagnoses potentially 'associated' with JH/HDCT by Baeza-Velasco et al is pretty long: "anxiety disorders, depression, schizophrenia, neurodevelopmental disorders (autism, attention deficit/hyperactivity disorder , and developmental coordination disorder), eating disorders, personality disorders and substance use/misuse."From the point-of-view of this blog, mention of the word 'autism' is perhaps the most important suggested link, harking back to some previous discussion of joint hypermobility and gait with the autism spectrum in mind (see here). I'm still pretty interested in seeing this issue followed up in the autism research arena bearing in mind the possible influence of comorbidity as per findings related to the presence of anxiety and joint hypermobility  and the question of which comes first: autism or hypermobility?Music: Glow by Ella Henderson.---------- Baeza-Velasco C. et al. Joint hypermobility and the heritable disorders of connective tissue: clinical and empirical evidence of links with psychiatry. Gen Hosp Psychiatry. 2014 Oct 16. pii: S0163-8343(14)00264-3. Baeza-Velasco C. et al. Connective tissue problems and attention deficit and hyperactivity. ADHD Attention Deficit and Hyperactivity Disorders. 2014. 1866-6647 Sanches SB. et al. Anxiety and joint hypermobility association: a systematic review. Rev Bras Psiquiatr. 2012 Jun;34 Suppl 1:S53-60.----------Baeza-Velasco C, Pailhez G, Bulbena A, & Baghdadli A (2014). Joint hypermobility and the heritable disorders of connective tissue: clinical and empirical evidence of links with psychiatry. General hospital psychiatry PMID: 25459977... Read more »
Baeza-Velasco C, Pailhez G, Bulbena A, & Baghdadli A. (2014) Joint hypermobility and the heritable disorders of connective tissue: clinical and empirical evidence of links with psychiatry. General hospital psychiatry. PMID: 25459977
The pituitary gland (in red). Image courtesy of Life Science Databases (LSDB).
Where is the pituitary gland?The pituitary gland is a small (about the size of a pea) endocrine gland that extends from the bottom of the hypothalamus. It is divided into two lobes in humans, the anterior pituitary and posterior pituitary. The anterior pituitary does not have direct neural connections to the hypothalamus, but is able to communicate with it through a system of blood vessels called the hypophyseal portal system. The posterior pituitary, however, is directly connected to the hypothalamus by a tube-like structure called the infundibular stalk.What is the pituitary gland and what does it do?The pituitary gland is often referred to as the "master gland" of the body because it is responsible for the release of hormones that regulate the activity of other endocrine glands and bodily systems; in this way it affects physiological processes throughout the body. Despite its directorial appellation, however, the function of the pituitary gland itself is controlled by the hypothalamus.The anterior pituitary is responsible for the synthesis and secretion of a collection of hormones that have manifold effects in a number of different physiological systems. Some of these hormones, along with a very simplified description of their actions, are: adrenocorticotropic hormone, which prompts the release of glucocorticoid hormones like cortisol; beta-endorphin, which is involved in natural pain relief; thyroid-stimulating hormone, which prompts the release of metabolic hormones from the thyroid; follicle-stimulating hormone and luteinizing hormone, which are involved in the proper functioning of the reproductive system; growth hormone, which promotes growth; and prolactin, which is involved in milk production in females. Of course the roles of each of these hormones is actually much more diverse and complex than this list indicates, but these are some of their best-known functions.The hypothalamus does not have neural connections with the anterior pituitary but it communicates with the gland via a system of blood vessels called the hypophyseal portal system. The hypothalamus secretes hormones called releasing hormones into the hypophyseal portal system; these hormones travel through the bloodstream to the anterior pituitary, where they act as signals to prompt the release of hormones like those listed above.The posterior pituitary is responsible for the release of two hormones: oxytocin and vasopressin. Unlike the anterior pituitary, however, the posterior pituitary does not synthesize its own hormones. Oxytocin and vasopressin are both synthesized in the hypothalamus, and then sent via neuroendocrine projections to the posterior pituitary. From there they are released them into the bloodstream. Oxytocin has roles in facilitating childbirth and lactation, but is also thought to play a role in promoting social bonding and compassion. Vasopressin, also known as antidiuretic hormone, is primarily involved in controlling urine output and regulating blood pressure.The pituitary gland is less than a centimeter in diameter, but it secretes hormones that have widespread effects on behavior and bodily function. Thus, despite its diminutive size it has justifiably earned the moniker of "master gland."Amar, A., & Weiss, M. (2003). Pituitary anatomy and physiology Neurosurgery Clinics of North America, 14 (1), 11-23 DOI: 10.1016/S1042-3680(02)00017-7null... Read more »
You might not want the dreaded tube socks in your Christmas stocking this year, but you do appreciate the actual tubes that your body depends on in just about every organ system. A recent paper in PLOS Biology describes tube formation in the fly renal system and the signals that regulate it. Tubes generally start as buds that dramatically elongate during development, but the cell rearrangements that occur during tubulogenesis are not completely understood. Saxena and colleagues recently used the developing fly renal system to track cell movements during tube formation. Tubule elongation primarily occurs through convergent extension, during which cells intercalate along the length of the tube. During these rearrangements, the number of cells around the circumference of the tube drops as the number of cells along the tube increases. Saxena and colleagues show that epidermal growth factor localized at the tip cells of the distal end of the tube guides the polarity of cell rearrangements, via polarization of Myosin II within individual cells. Finally, without proper tube elongation, animals have abnormal excretory function and osmoregulation, leading to lethality. In the images above, the top row shows failure of tube elongation after laser ablation of the distal tip cells (arrowheads). Bottom row shows normal tube elongation without laser ablation of tip cells (arrowheads). Saxena, A., Denholm, B., Bunt, S., Bischoff, M., VijayRaghavan, K., & Skaer, H. (2014). Epidermal Growth Factor Signalling Controls Myosin II Planar Polarity to Orchestrate Convergent Extension Movements during Drosophila Tubulogenesis PLoS Biology, 12 (12) DOI: 10.1371/journal.pbio.1002013... Read more »
Saxena, A., Denholm, B., Bunt, S., Bischoff, M., VijayRaghavan, K., & Skaer, H. (2014) Epidermal Growth Factor Signalling Controls Myosin II Planar Polarity to Orchestrate Convergent Extension Movements during Drosophila Tubulogenesis. PLoS Biology, 12(12). DOI: 10.1371/journal.pbio.1002013
Thanks to the internet age we have lost touch with the fact that there is a human out there reading these words. Because of this, the golden rule –treat others the way you want to be treated — went out the window. Making fun of “fat” people now seems to be a internet hobby and that insensitivity can (and does) bleed over into “normal” non-internet life. Now a new study shows that women whose loved ones are critical of their weight tend to put on even more pounds, which is probably no surprise to people who have experienced this behavior.... Read more »
LOGEL, C., STINSON, D., GUNN, G., WOOD, J., HOLMES, J., & CAMERON, J. (2014) A little acceptance is good for your health: Interpersonal messages and weight change over time. Personal Relationships, 21(4), 583-598. DOI: 10.1111/pere.12050
What are the sights, the sounds, the smells, and the textures that you associate with Christmas? Perhaps it is Christmas trees with their lovely green shape, color and wonderful pine smell. Maybe it’s the smells of cooking, the savory smells of turkey or the sweet smell of warm cookies. Or what about all of the cozy feelings you get with big sweaters or a roaring fire? Did you know that there is a lot of chemistry that goes into all of the senses we associate with this holiday?I was browsing through holiday-related articles, looking for something different from the usual psychology or sociology centered holiday study. That’s when I came across an article from 2012 published in the Journal of Chemical Education about the five senses of Christmas chemistry. The authors look through the lens of organic chemistry and take five “Christmas compounds” to examine in the context of the five senses.Sound: Silver FulminateIn 1824, Justus Liebig correctly determined the molecular formula of silver fulminate (AgCNO), and, around the same time, Friedrich Wohler identified the molecular formula for silver cyanate (AgOCN). Now, these might look the same, but they are in fact very different. Soon after, these scientists collaborated and rationalized these differences by introducing the notion of isomerism – molecules that have the same kinds of atoms but because these atoms have different arrangements in shape they differ in their chemical and physical properties. Silver fulminate is highly unstable, and even a small amount of friction leads to its violent decomposition. That makes it very useful when you want to make things go boom.Christmas crackers are items that are a more traditional favorite in the UK. The Christmas crackers used today are short cardboard tubes wrapped in colorful paper. When they are pulled – bang! – out comes a colorful hat (usually looking like a crown), a small toy or a joke. The sound is made from the rapid breakdown of silver fulminate present in small quantities in the paper. Two thin strips of cardboard are glued together, one containing silver fulminate and the other a rough surface. When the cracker is pulled, the surfaces rub together to produce friction and facilitate the reaction. The compound goes through a redox reaction followed by a release of nitrogen gas and carbon monoxide. This sudden production of gases is what produces the distinctive popping sounds.Sight: α-pineneA beautifully lit and decorated Christmas tree is one of the most common sights of this holiday. For the purposes of this section, we’ll assume that you bought a real tree rather than an artificial one. Geographic region can play a big part in the species of tree that is available to you, but they are very likely all evergreens (fir, spruce, pine, and cedars). In their resin, these conifers release terpene hydrocarbons, specifically monoterpenoids that is composed of two isoprene building blocks. This word should sound familiar as it is a derivative of turpentine, which you may know for its distinctive pine scent. Pine oil contains two monoterpenoids, α-pinene and β-pinene, which are both liquid at room temperature. This is another case of isomerism; although both have the typical C10H16 molecular formula there are four stereoisomers of each where the bonded atoms differing in their 3-D orientations. α-pinene is one of the most common volatiles in nature and is directly linked to the Christmas tree’s smell. Touch: Sodium Acetate I don’t live in what most people would term a cold climate. Sure, we get cold weather, but we’re not talking blizzards. However, in my days as a field ecologist I spent many a winter day outside taking measurements. On those days, I was ever-so-grateful for one little invention: the hand warmer. Squish around the contents of the packet to get it to heat up to keep you pockets, and hands, toasty all day long. Bliss.Many hand warmers are based on a simple chemical reaction – the crystallization of a supersaturated sodium acetate solution. When you squish around the contents of the hand warmer, you are triggering a chemical process. A nucleation site, usually a metal disk with small seed crystals, causes rapid crystallization of the super saturated solution. This is a highly exothermic process that releases energy to its surroundings as heat. These types of hand warmers are often reusable because of their physical mode of action. Other hand warmers rely on the exothermic oxidation of iron when exposed to air. Activated charcoal is used to catalyze the reaction, along with vermiculite and salt as additives. However, this chemical mode of action means that these are one use only products.Taste: TryptophanIf you are a fan of a big turkey dinner then you have probably heard of tryptophan. It is a common misconception that the tryptophan from your turkey binge brings on sleepiness. It’s true that tryptophan is involved in sleep and mood control. However, turkey doesn’t contain enough of the compound (only 350 mg per 115 g) to have a soporific effect. It’s more likely that the sheer volume of food that you eat (and probably the wine you drank with it) on these occasions decreases blood flow and oxygenation, inducing the drowsiness.Tryptophan is an essential aromatic amino acid that is commonly found in proteins. This compound has two enantiomers, chiral molecules that are mirror images of one another (kinda like left and right hands). L-tryptophan exists in nature and has a pronounced bitter taste, while D-tryptophan is synthetic and has a very sweet taste. Once you consume tryptophan, it goes through a series of metabolic reactions, one of which ends with melatonin. This final product is a neurohormone that is naturally secreted by the pineal gland, is involved in regulating circadian rhythms and may also have strong antioxidant effects.Smell: GingerolGingersnap cookies and gingerbread houses are common sights around the holidays, and with them come their wonderful ginger scent. Ginger products usually contain fresh or powdered bits from the rhizomes (rootstalk, or modified underground stem) of the ginger plant (Zingiber officinale). One of the organic compounds produced by this plant is gingerol, an aromatic vanilloid compound containing a β-hydroxyketone functionality. Interestingly, the taste of this compound can be modified via laboratory synthesis. Shogaol is derived by either refluxing gingerol with concentrated sulfuric acid or allowing a dehydration reaction can occur on gingerol to give the aldol condensation product. Shogaol has a more pungent flavor than gingerol. Conversely, ginergol can completely break down into zingerone after refluxing in strong aqueous base. Zingerone is considered to have less pungency than gingerol.Considering this chemistry, you can alter the flavor of the ginger you use in your cooking. For example, if you cook ginger extensively, particularly in the absence of acid, then you produce the mildest tasting vanilloids, zingerone. But also keep in mind that your kitchen conditions are not laboratory conditions. This means that you are likely to end up with a mixture of all three compounds in your cookies.That’s all for our journey through the senses of Christmas. If you are a chemistry teacher, or simply a chemistry nut, then I recommend reading through the paper. It has all sorts of skeletal formulas that you’ll love.... Read more »
Even a brilliant dog may not be able to count as high as the number of feet she has. In a cheese cube counting challenge, dogs struggled to prove they have any number sense at all. Embarrassingly for the dogs, some wolves took the exact same test and passed it. This may be a hint about what dogs lost when they moved to a cushy life of domestication.
At the Wolf Science Center in Austria, Friederike Range and her colleagues raise both wolves and dogs by hand, then train them to take part i... Read more »
Range F, Jenikejew J, Schröder I, & Virányi Z. (2014) Difference in quantity discrimination in dogs and wolves. Frontiers in psychology, 1299. PMID: 25477834
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