Embryonic development of the stress hormone axis in two model teleost species

Glucocorticoid hormones mediate stress responses in all vertebrates, from teleost fishes to mammals. In adult teleosts, the primary glucocorticoid, cortisol, is synthesized within interrenal tissue via enzyme-mediated reactions regulated by the hypothalamic-pituitary-interrenal (HPI) axis in response to stressors. The hypothalamic peptide corticotropin-releasing hormone (CRH) stimulates release of the pituitary protein adrenocorticotropin hormone (ACTH), which stimulates cortisol production in interrenal cells. Cortisol affects target cells via two types of receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). The timing and sequence of events leading to a fully functioning HPI axis in developing nonmammalian vertebrates is not fully known. Addressing this gap, we measured expression of genes involved in cortisol synthesis and signaling throughout embryogenesis in two teleosts, the zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes). We isolated RNA from pools of embryos collected at multiple developmental stages and synthesized complementary DNA (cDNA) by reverse transcription. Using cDNA as a template, we measured relative expression of key HPI genes, including CRH, melanocortin type 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR), 11 β hydroxysteroid dehydrogenase (HSD2), and MR by quantitative polymerase chain reaction (qPCR). We measured cortisol throughout embryogenesis using an enzyme-linked immunosorbent assay (ELISA). We found noteworthy differences in expression profiles for all measured genes between species. Notably, we saw large differences in magnitude for changes in CRH, MC2R, and StAR expression. HSD2 showed different patterns of expression in zebrafish and medaka. Temporal cortisol patterns differed between species. Medaka cortisol increased significantly for hatch, whereas zebrafish saw a significant decrease

On Secular Stagnation in the Industrialized World

We argue that the economy of the industrialized world taken as a whole is currently – and for the foreseeable future will remain – highly prone to secular stagnation. But for extraordinary fiscal policies, real interest rates would have fallen much more and be far below their current slightly negative level, current and prospective inflation would be further short of the two percent target levels and past and future economic recoveries would be even more sluggish. We start by arguing that, contrary to current practice, neutral real interest rates are best estimated for the bloc of all industrial economies given capital mobility between them and relatively limited fluctuations in their aggregated current account. We show, using standard econometric procedures and looking at direct market indicators of prospective real rates, that neutral real interest rates have declined by at least 300 basis points over the last generation. We argue that these secular movements are in larger part a reflection of changes in saving and investment propensities rather than the safety and liquidity properties of Treasury instruments. We highlight the observation that levels of government debt, the extent of pay-as-you-go old age pensions and the insurance value of government healthcare programs have all ceteris paribus operated to raise neutral real rates. Using estimates drawn from the literature, as well as two general equilibrium models emphasizing respectively life-cycle heterogeneity and individual uncertainty, we suggest that the “private sector neutral real rate” may have declined by as much as 700 basis points since the 1970s

Acoustics and Biological Structures

Within the context of noise-induced health effects, the impact of airborne acoustical phenomena on biological tissues, particularly within the lower frequency ranges, is very poorly understood. Although the human body is a viscoelastic-composite material, it is generally modeled as Hooke elastic. This implies that acoustical coupling is considered to be nonexistent at acoustical frequencies outside of the human auditory threshold. Researching the acoustical properties of mammalian tissue raises many problems. When tissue samples are investigated as to their pure mechanical properties, stimuli are not usually in the form of airborne pressure waves. Moreover, since the response of biological tissue is dependent on frequency, amplitude, and time profile, precision laboratory equipment and relevant physiological endpoints are mandatory requirements that are oftentimes difficult to achieve. Drawing upon the viscoelastic nature of biological tissue and the tensegrity model of cellular architecture, this chapter will visit what is known to date on the biological response to a variety of different acoustic stimuli at very low frequencies

Vivir la Música: Spanish cultural identity examined through the lens of Spanish classical piano music

Spanish cultural identity is examined, with the purpose of providing a possible answer to the very complex question of “what does it mean to be Spanish?”. This is achieved through the analysis of Spanish classical piano music, using techniques from ethnomusicology, music psychology, linguistics, and linguistic anthropology. Music, while not explicitly communicative like language, has communicative, representational, and referential abilities and therefore is examined using theories from linguistics and linguistic anthropology. The anthropologist’s understanding of the theory of linguistic relativity (Sapir-Whorf Hypothesis) is slightly rewritten, with language replaced by music, to show how music, thought, and culture have a mutually influential relationship. The implications of this relationship for Spanish culture and music are examined, with special emphasis on two of the major works of Spanish piano music: Enrique Granados's Goyescas, and Isaac Albéniz's Iberia

Risk factors for stress fracture in female endurance athletes : a cross-sectional study

Objective To identify psychological and physiological correlates of stress fracture in female endurance athletes. Design A cross-sectional design was used with a history of stress fractures and potential risk factors assessed at one visit. Methods Female-endurance athletes (58 runners and 12 triathletes) aged 26.0±7.4 years completed questionnaires on stress fracture history, menstrual history, athletic training, eating psychopathology and exercise cognitions. Bone mineral density, body fat content and lower leg lean tissue mass (LLLTM) were assessed using dual-x-ray absorptiometry. Variables were compared between athletes with a history of stress fracture (SF) and those without (controls; C) using χ², analysis of variance and Mann-Whitney U tests. Results Nineteen (27%) athletes had previously been clinically diagnosed with SFs. The prevalence of current a/oligomenorrhoea and past amenorrhoea was higher in SF than C (p=0.008 and p=0.035, respectively). SF recorded higher global scores on the eating disorder examination questionnaire (p=0.049) and compulsive exercise test (p=0.006) and had higher LLLTM (p=0.029) compared to C. These findings persisted with weight and height as covariates. In multivariate logistic regression, compulsive exercise, amenorrhoea and LLLTM were significant independent predictors of SF history (p=0.006, 0.009 and 0.035, respectively). Conclusions Eating psychopathology was associated with increased risk of SF in endurance athletes, but this may be mediated by menstrual dysfunction and compulsive exercise. Compulsive exercise, as well as amenorrhoea, is independently related to SF risk

Dual trigger protocol is an effective IVF strategy in both normal and high responders without compromising pregnancy outcomes

To compare pregnancy outcomes between normal versus high responders after dual trigger of final oocyte maturation with gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) in fresh in-vitro fertilization (IVF) cycles, where ovarian stimulation was achieved by a flexible GnRH antagonist protocol

Flow-Based Cytometric Analysis of Cell Cycle via Simulated Cell Populations

We present a new approach to the handling and interrogating of large flow cytometry data where cell status and function can be described, at the population level, by global descriptors such as distribution mean or co-efficient of variation experimental data. Here we link the “real” data to initialise a computer simulation of the cell cycle that mimics the evolution of individual cells within a larger population and simulates the associated changes in fluorescence intensity of functional reporters. The model is based on stochastic formulations of cell cycle progression and cell division and uses evolutionary algorithms, allied to further experimental data sets, to optimise the system variables. At the population level, the in-silico cells provide the same statistical distributions of fluorescence as their real counterparts; in addition the model maintains information at the single cell level. The cell model is demonstrated in the analysis of cell cycle perturbation in human osteosarcoma tumour cells, using the topoisomerase II inhibitor, ICRF-193. The simulation gives a continuous temporal description of the pharmacodynamics between discrete experimental analysis points with a 24 hour interval; providing quantitative assessment of inter-mitotic time variation, drug interaction time constants and sub-population fractions within normal and polyploid cell cycles. Repeated simulations indicate a model accuracy of ±5%. The development of a simulated cell model, initialized and calibrated by reference to experimental data, provides an analysis tool in which biological knowledge can be obtained directly via interrogation of the in-silico cell population. It is envisaged that this approach to the study of cell biology by simulating a virtual cell population pertinent to the data available can be applied to “generic” cell-based outputs including experimental data from imaging platforms

Higher body weight is associated with lower concentrations of progesterone and estrogen in early pregnancy following in vitro fertilization

To evaluate if body weight impacts progesterone and estradiol concentration levels in early pregnancy in women conceiving following single embryo transfer

Risk factors for stress fracture in female endurance athletes: a cross-sectional study

Objective: To identify psychological and physiological correlates of stress fracture in female endurance athletes. Design: A cross-sectional design was used with a history of stress fractures and potential risk factors assessed at one visit. Methods: Female-endurance athletes (58 runners and 12 triathletes) aged 26.0±7.4 years completed questionnaires on stress fracture history, menstrual history, athletic training, eating psychopathology and exercise cognitions. Bone mineral density, body fat content and lower leg lean tissue mass (LLLTM) were assessed using dual-x-ray absorptiometry. Variables were compared between athletes with a history of stress fracture (SF) and those without (controls; C) using χ², analysis of variance and Mann-Whitney U tests. Results: Nineteen (27%) athletes had previously been clinically diagnosed with SFs. The prevalence of current a/oligomenorrhoea and past amenorrhoea was higher in SF than C (p=0.008 and p=0.035, respectively). SF recorded higher global scores on the eating disorder examination questionnaire (p=0.049) and compulsive exercise test (p=0.006) and had higher LLLTM (p=0.029) compared to C. These findings persisted with weight and height as covariates. In multivariate logistic regression, compulsive exercise, amenorrhoea and LLLTM were significant independent predictors of SF history (p=0.006, 0.009 and 0.035, respectively). Conclusions: Eating psychopathology was associated with increased risk of SF in endurance athletes, but this may be mediated by menstrual dysfunction and compulsive exercise. Compulsive exercise, as well as amenorrhoea, is independently related to SF risk

A transfer function approach to measuring cell inheritance

<p>Abstract</p> <p>Background</p> <p>The inheritance of cellular material between parent and daughter cells during mitosis is highly influential in defining the properties of the cell and therefore the population lineage. This is of particular relevance when studying cell population evolution to assess the impact of a disease or the perturbation due to a drug treatment. The usual technique to investigate inheritance is to use time-lapse microscopy with an appropriate biological marker, however, this is time consuming and the number of inheritance events captured are too low to be statistically meaningful.</p> <p>Results</p> <p>Here we demonstrate the use of a high throughput fluorescence measurement technique e.g. flow cytometry, to measure the fluorescence from quantum dot markers which can be used to target particular cellular sites. By relating, the fluorescence intensity measured between two time intervals to a transfer function we are able to deconvolve the inheritance of cellular material during mitosis. To demonstrate our methodology we use CdTe/ZnS quantum dots to measure the ratio of endosomes inherited by the two daughter cells during mitosis in the U2-OS, human osteoscarcoma cell line. The ratio determined is in excellent agreement with results obtained previously using a more complex and computational intensive bespoke stochastic model.</p> <p>Conclusions</p> <p>The use of a transfer function approach allows us to utilise high throughput measurement of large cell populations to derive statistically relevant measurements of the inheritance of cellular material. This approach can be used to measure the inheritance of organelles, proteins etc. and also particles introduced to cells for drug delivery.</p