White-Matter Development is Different in Bilingual and Monolingual Children: A Longitudinal DTI Study

Although numerous people grow up speaking more than one language, the impact of bilingualism on brain developing neuroanatomy is still poorly understood. This study aimed to determine whether the changes in the mean fractional-anisotropy (MFA) of language pathways are different between bilingual and monolingual children. Simultaneous-bilinguals, sequential-bilinguals and monolingual, male and female 10–13 years old children participated in this longitudinal study over a period of two years. We used diffusion tensor tractography to obtain mean fractional-anisotropy values of four language related pathways and one control bundle: 1-left-inferior-occipitofrontal fasciculus/lIFOF, 2-left-arcuate fasciculus/lAF/lSLF, 3-bundle arising from the anterior part of corpus-callosum and projecting to orbital lobe/AC-OL, 4-fibres emerging from anterior-midbody of corpus-callosum (CC) to motor cortices/AMB-PMC, 5- right-inferior-occipitofrontal fasciculus rIFOF as the control pathway unrelated to language. These values and their rate of change were compared between 3 groups. FA-values did not change significantly over two years for lAF/lSLF and AC-OL. Sequential-bilinguals had the highest degree of change in the MFA value of lIFOF, and AMB-PMC did not present significant group differences. The comparison of MFA of lIFOF yielded a significantly higher FA-value in simultaneous bilinguals compared to monolinguals. These findings acknowledge the existing difference of the development of the semantic processing specific pathway between children with different semantic processing procedure. These also support the hypothesis that age of second language acquisition affects the maturation and myelination of some language specific white-matter pathways.     

Statistical Mechanics of Zooplankton

Statistical mechanics provides the link between microscopic properties of many-particle systems and macroscopic properties such as pressure and temperature. Observations of similar “microscopic” quantities exist for the motion of zooplankton, as well as many species of other social animals. Herein, we propose to take average squared velocities as the definition of the “ecological temperature” of a population under different conditions on nutrients, light, oxygen and others. We test the usefulness of this definition on observations of the crustacean zooplankton Daphnia pulicaria. In one set of experiments, D. pulicaria is infested with the pathogen Vibrio cholerae, the causative agent of cholera. We find that infested D. pulicaria under light exposure have a significantly greater ecological temperature, which puts them at a greater risk of detection by visual predators. In a second set of experiments, we observe D. pulicaria in cold and warm water, and in darkness and under light exposure. Overall, our ecological temperature is a good discriminator of the crustacean’s swimming behavior.     

Elicitor-induced hydroxycinnamoyl-CoA:tyramine hydroxycinnamoyltransferase in plant cell suspension cultures

Treatment of Nicotiana glutinosa L. cell suspension cultures with chitosan results in the co-induction of phenylalanine ammonia lyase, 4-eoumarate:CoA ligase, tyrosine decarboxylase and tyramine hydroxycinnamoyltransferase, all involved in the biosynthesis of hydroxycinnamoyltyramines. The highest enzyme activities were observed around 12 h after addition of 0.8 to 1 mg chitosan per g fresh weight of cells. No hydroxycinnamoyltyramines could be detected by TLC or HPLC of extracts made from non-treated or elicited cells. [¹⁴C]-Tyramine was incorporated into insoluble polymeric material at a higher rate in elicitor-treated than in non-treated cells of N. glutinosa. Tyramine hydroxycinnamoyltransferase could be induced in suspension cultured cells of Eschscholtzia califortnca Cham, but not in cells of Phaseolus vulgaris L. or Catharanthus roseus (L.) G. Don by addition of a yeast elicitor to the growth medium.     

Autonomic Adaption to Clinical Simulation in Psychology Students: Teaching Applications

Simulation is used to facilitate new learning in a variety of situations. One application of simulation could be to help therapists gain therapeutic skills prior to seeing clients. This particular study was interested in measuring changes in stress response by looking at subjective and objective measures of distress (as measured by SUDS, HR, and HRV) over three sessions of simulated therapy. 16 second year psychology students participated in three sessions, and had their HR and HRV measured by Polar watches. Over the three sessions, there was a decrease in perceived distress, as measured by SUDS ratings. During and between sessions, there was inconclusive change in physiological parameters.     

Annual Records of Airborne Pollen of Poaceae in Five Areas in Lagos,Nigeria

Poaceae pollen grains are known to be highly allergenic and they are potential causes of allergic respiratory diseases. In order to investigate the incidence of airborne Poaceae, and contribute to current trends in the development of aeropalynology/allergy studies in Nigeria, five highly populated locations in Central Lagos State, Surulere, Ebute-Metta, University of Lagos, Bariga and Gbagada, were sampled. Gravimetric aerosamples were collected monthly from January 2013 to December 2014. The lowest count in 2013 was recorded in the Ebute-Metta area (179), while the highest in 2013 was recorded in Gbagada (564). In 2014, the Surulere area (282) had the lowest count while Bariga (671) had the highest. The locations have similar monthly pollen distribution pattern but different peak months. Generally, Poaceae pollen counts were lowest in the months of June and July. These are therefore the safest months for Poaceae pollen hypersensitive individuals in the study areas. Relative humidity was the most important meteorological parameter with significant correlations in Ebute-Metta and Bariga locations. Results from this work will form the basis for a forecast service required to inform and educate the general public and allergy sufferers about Poaceae pollen distribution in Lagos State.     

Shedding of Endogenous Interleukin-6 Receptor (IL-6R) Is Governed by A Disintegrin and Metalloproteinase (ADAM) Proteases while a Full-length IL-6R Isoform Localizes to Circulating Microvesicles

Generation of the soluble interleukin-6 receptor (sIL-6R) is a prerequisite for pathogenic IL-6 trans-signaling, which constitutes a distinct signaling pathway of the pleiotropic cytokine interleukin-6 (IL-6). Although in vitro experiments using ectopically overexpressed IL-6R and candidate proteases revealed major roles for the metalloproteinases ADAM10 and ADAM17 in IL-6R shedding, the identity of the protease(s) cleaving IL-6R in more physiological settings, or even in vivo, remains unknown. By taking advantage of specific pharmacological inhibitors and primary cells from ADAM-deficient mice we established that endogenous IL-6R of both human and murine origin is shed by ADAM17 in an induced manner, whereas constitutive release of endogenous IL-6R is largely mediated by ADAM10. Although circulating IL-6R levels are altered in various diseases, the origin of blood-borne IL-6R is still poorly understood. It has been shown previously that ADAM17 hypomorphic mice exhibit unaltered levels of serum sIL-6R. Here, by quantification of serum sIL-6R in protease-deficient mice as well as human patients we also excluded ADAM10, ADAM8, neutrophil elastase, cathepsin G, and proteinase 3 from contributing to circulating sIL-6R. Furthermore, we ruled out alternative splicing of the IL-6R mRNA as a potential source of circulating sIL-6R in the mouse. Instead, we found full-length IL-6R on circulating microvesicles, establishing microvesicle release as a novel mechanism for sIL-6R generation.     

Using three-point bending to evaluate tibia bone strength in ovariectomized young mice

It is well known that estrogen deficiency induces a deterioration of bone strength in aged females. The aim of this study is to determine the effect of estrogen depletion on tibia bone strength in sexually mature mice that are still undergoing skeletal maturation. At 8 weeks of age, C57BL/6 female mice underwent an ovariectomy (OVX) or sham (SHAM) surgery. Mice were killed at 2, 4, or 8 weeks post-surgery. Tibia length and cross-sectional area continued to increase in both treatment groups until 4 weeks post-surgery. Compared to SHAM mice, OVX mice demonstrated a significant reduction in uterine weight and plasma estrogen levels. Three-point bending was used to quantify the mechanical properties (breaking point, stress, stiffness, and elasticity) of the tibia. The tibias from the SHAM mice had a higher breaking point than all the age-matched OVX mice. At 8 weeks post-surgery, the tibias from the SHAM mice demonstrated higher elasticity, stress, and stiffness than the younger SHAM mice and the age-matched OVX mice. Compared to the SHAM mice, our study suggests that (1) there is a reduction in the mechanical strength of tibias from young OVX mice, and (2) the greatest decline in tibia strength of the OVX mice was once they reached skeletal maturity.     

Septal and Hippocampal Glutamate Receptors Modulate the Output of Acetylcholine in Hippocampus: A Microdialysis Study

Abstract: In the present study, glutamate receptor agonists and antagonists were administered by retrograde microdialysis into either the medial septum/vertical limb of the diagonal band (MS/vDB), or hippocampus, and the output of acetylcholine (ACh) was measured in the hippocampus by using intracerebral microdialysis. Perfusion with N -methyl- d -aspartate (NMDA) and ( S )-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in the MS/vDB caused an increase in ACh output in the hippocampus. This increase was completely blocked by coadministration of their respective antagonists d (−)-2-amino-5-phosphonopentanoic acid ( d -AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Perfusion in the MS/vDB with kainic acid also caused an increase in ACh output, but coadministration of CNQX attenuated the increase only partially. Perfusion with d -AP5 or CNQX alone in the septal probe did not affect ACh output from the hippocampus. In contrast to the results of septal administration of NMDA and AMPA, local perfusion with the same drugs in the hippocampus caused a decrease in ACh output. Whereas the results of septal administration of drugs indicate that septal cholinergic neurons probably receive excitatory glutamatergic innervation, the decrease in ACh output caused by administration of NMDA and AMPA in the hippocampus is poorly understood.