Effects of ancient and modern, avoidant and approach stimuli on visual search task reaction times

The threat superiority effect refers to faster and more accurate detection of fearful stimuli. This has been explained as evidence for evolution, as ancient fearful stimuli are detected more quickly than modern fearful stimuli. The aim of this study was to investigate which of two alternate evolutionary explanations best explains the findings. Whereas Ohman and Mineka (2001) dealt only with avoidant responses, Lang suggested that stimuli may evoke either an avoidant (fearful) or approach response, associated with negative or positive valence, respectively. The experiment employed a same-different task where Age (ancient, modern), and Valence (approach, avoidant, neutral) were manipulated and presented to 37 (19 females and 18 males) participants. Participants were presented with slides of 9 images, and asked to determine whether all images come from the same category (for example they are all flowers) or a different category (there is a snake among the flowers) as quickly and as accurately as possible. Ancient approach (horses) and avoidant (snakes) stimuli were detected faster than the neutral stimuli (mushrooms), but both modern approach (pizzas) and modern neutral (clocks) stimuli were detected faster than avoidant (guns) stimuli. These findings are most consistent with the evolutionary explanation of Lang (1995). It is suggested that the disparate results in the literature may be due to confounds associated with stimulus similarity

Regulation of Lipid Homeostasis, Inflammatory Signalling and Atherosclerosis by the Peroxisome Proliferator-Activated Receptor Delta

The peroxisome proliferator-activated receptor (PPAR) δ is a ligand-dependent transcription factor that has been implicated in metabolic and inflammatory regulation. The molecular and physiological mechanisms by which PPARδ activation regulates lipid metabolism, inflammatory signaling and protection from atherosclerosis in states of metabolic disturbance such as insulin resistance and dyslipidemia, were investigated in a series of in vitro and in vivo studies. In vitro experiments demonstrated that PPARδ activation inhibits atherogenic lipoprotein-induced lipid accumulation and the associated proinflammatory responses. The primary mechanisms for these effects were increased fatty acid β-oxidation, decreased lipoprotein lipase (LPL) activity, reduced MAPK signaling and improved insulin signaling. With regard to cholesteryl ester (CE)-rich low-density lipoprotein (LDL), the PPARδ activators stimulated cholesterol efflux via ABCA1 to apoAI, resulting in the inhibition of native and modified LDL-induced CE accumulation. In vivo studies were conducted in high fat, high cholesterol (HFHC)-fed low-density lipoprotein receptor null (Ldlr-/-) mice. Following a 4-week induction phase of HFHC-feeding to stimulate early atherosclerotic lesion development, dietary supplementation with GW1516 for a subsequent 8-weeks prevented further plaque progression. This prevention was linked to inhibition of dyslipidemia, hyperinsulinemia, and glucose and insulin intolerance. Furthermore, GW1516 strongly attenuated aortic inflammation, insulin resistance and endoplasmic reticulum (ER)-stress, which likely contributed to inhibition of lesion progression. Additional studies in the liver showed that PPARδ activation inhibits hepatic TG accumulation induced by HFHC-feeding. To further probe the mechanism for this effect, experiments were conducted in primary mouse hepatocytes isolated from wild-type (WT) or adenosine monophosphate-activated protein kinase (AMPK) β1-/- mice. These studies revealed that PPARδ activation in the liver stimulates fat oxidation due to upregulation of the PPARδ-target gene carnitine palmitoyl transferase (Cpt) 1a, which was independent of AMPK activation. Furthermore, GW1516 inhibited de novo lipogenesis, which was partially dependent on AMPK activation. The residual inhibitory effect on fatty acid synthesis was associated with correction of selective hepatic insulin resistance. In summary, these studies provide significant insight and support for PPARδ activation as a therapeutic strategy to treat the dysregulation of lipid homeostasis, inflammatory signaling, metabolic disease, and their cardiovascular complications

Mindfulness-based treatment for bipolar disorder: A systematic review of the literature

Despite the increasing number of studies examining the effects of mindfulness interventions on symptoms associated with Bipolar Disorder (BD), the effectiveness of this type of interventions remains unclear. The aim of the present systematic review was to (i) critically review all available evidence on Mindfulness Based Cognitive Therapy (MBCT) as a form of intervention for BD; (ii) discuss clinical implications of MBCT in treating patients with BD; and (iii) provide a direction for future research. The review presents findings from 13 studies (N = 429) that fulfilled the following selection criteria: (i) included BD patients; (ii) presented results separately for BD patients and control groups (where a control group was available); (iii) implemented MBCT intervention; (iv) were published in English; (v) were published in a peer reviewed journal; and (vi) reported results for adult participants. Although derived from a relatively small number of studies, results from the present review suggest that MBCT is a promising treatment in BD in conjunction with pharmacotherapy. MBCT in BD is associated with improvements in cognitive functioning and emotional regulation, reduction in symptoms of anxiety depression and mania symptoms (when participants had residual manic symptoms prior to MBCT). These, treatment gains were maintained at 12 month follow up when mindfulness was practiced for at least 3 days per week or booster sessions were included. Additionally, the present review outlined some limitations of the current literature on MBCT interventions in BD, including small study sample sizes, lack of active control groups and idiosyncratic modifications to the MBCT intervention across studies. Suggestions for future research included focusing on factors underlying treatment adherence and understanding possible adverse effects of MBCT, which could be of crucial clinical importance

Biosorptive removal of Pb2+, Cd2+ and Zn2+ ions from water by agenaria vulgaris shell

Lagenaria vulgaris (LV) shell was used as a biosorbent for the removal of heavy metal ions, Pb2+, Cd2+ and Zn2+, from aqueous solutions. Experiments were carried out under batch conditions. The effects of contact time, initial pH, temperature and stirring speed on removal efficiency are presented. Sorption of the investigated metals was fast, reaching equilibrium after about 5 to 10 min, depending on the metal. Biosorption was highly pH-dependent, and the optimal pH for investigated metals was in the range of 4.5 to 6.0. The effects of temperature demonstrated that biosorption of the metals is a chemical process. SEM analysis revealed interesting morphological changes after acid refinement of the raw biosorbent and metal uptake that is related to the chemical nature of the biosorption process. EDX analysis of Lagenaria vulgaris biosorbent(LVB) before and after metal sorption revealed that the ion exchange mechanism was the principal sorption process. Fourier transform infrared spectroscopy (FTIR) analysis has shown that major functional groups (carboxyl and hydroxyl) on the biosorbent surface took part in the metal ion uptake process as active sites. The results obtained showed that Lagenaria vulgaris based biosorbent could be used as an effective and low-cost pre-treatment step for removal of toxic metals from wastewaters

Scaling of city attractiveness for foreign visitors through big data of human economical and social media activity

Scientific studies investigating laws and regularities of human behavior are nowadays increasingly relying on the wealth of widely available digital information produced by human social activity. In this paper we leverage big data created by three different aspects of human activity (i.e., bank card transactions, geotagged photographs and tweets) in Spain for quantifying city attractiveness for the foreign visitors. An important finding of this papers is a strong superlinear scaling of city attractiveness with its population size. The observed scaling exponent stays nearly the same for different ways of defining cities and for different data sources, emphasizing the robustness of our finding. Temporal variation of the scaling exponent is also considered in order to reveal seasonal patterns in the attractivenessComment: 8 pages, 3 figures, 1 tabl

Optimisation of protocols for ex vivo expansion of limbal stem cells and their enrichment

Ph. D. ThesisThe corneal epithelial cells are constantly replaced by the stem cells located at the limbus, the peripheral edge of the cornea, therefore known as limbal stem cells (LSCs). LSCs can be destroyed by numerous factors which results in the condition called limbal stem cell deficiency (LSCD). Ex vivo expansion of LSCs is a well-established technique used successfully to cure patients with LSCD. Therapeutic use of LSCs must be performed in compliance with good manufacturing practice (GMP) as a quality assurance system. However, traditional culture media for ex vivo expansion of LSCs contains a number of ingredients derived from animal sources which may compromise its safety profile for human transplantation. The first aim of the study was to define new GMP grade medium for cultivation and maintenance of LSCs in vitro. Formulation of new GMP compliant media resulted in equal growth to non-GMP grade media. Strick regulations for cell therapy promote centralization of culture units, therefore definition of reliable and practical transportation strategies is vitally important. The second aim of this study was to optimise the transport conditions for limbal biopsies (LBs) and cultured limbal epithelial cells (LECs). Transport of LBs at room temperature proved to be significantly superior to 4°C transport. We also showed that cultured LECs may be stored in serumfree media and transported up to 7 days at 23°C without any negative effect on cell number, viability, colony forming efficiency or gene expression profile. Due to the absence of specific LSC markers, identification and isolation of putative LSCs is a complicated task. The third and final aim of this study was to identify novel cell surface markers for LSCs. We reported herein the identification of a new cell surface marker for LSCs (CD200) as well as a cell surface marker for proliferating progenitor cells (CD109)

Business Plan for Virtual User Portal

Virtual User Portal (VUP) is a Vancouver based start-up company, currently building an ‘experience’ marketplace designed to connect experience seekers with local experience providers. This business plan examines the viability of VUP’s business model. The industry analysis is conducted to determine the intensity of competition and profit potential. The market analysis defines the target market and VUP’s positioning in the marketplace. As a result, we built pro-forma financial statements that show two important predictions: VUP will become profitable after two years of operation and there is a need to raise additional 500,000 to support the growth

Seeding hESCs to achieve optimal colony clonality

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) have promising clinical applications which often rely on clonally-homogeneous cell populations. To achieve this, cross-contamination and merger of colonies should be avoided. This motivates us to experimentally study and quantitatively model the growth of hESC colonies. The colony population is unexpectedly found to be multi-modal. We associate these sub-populations with different numbers of founding cells, and predict their occurrence by considering the role of cell-cell interactions and cell behaviour on randomly seeded cells. We develop a multi-population stochastic exponential model for the colony population which captures our experimental observations, and apply this to calculate the timescales for colony merges and over which colony size no longer predicts the number of founding cells. These results can be used to achieve the best outcome for homogeneous colony growth from different cell seeding densities

Seeding hESCs to achieve optimal colony clonality

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) have promising clinical applications which often rely on clonally-homogeneous cell populations. To achieve this, it is important to ensure that each colony originates from a single founding cell and to avoid subsequent merging of colonies during their growth. Clonal homogeneity can be obtained with low seeding densities; however, this leads to low yield and viability. It is therefore important to quantitatively assess how seeding density affects clonality loss so that experimental protocols can be optimised to meet the required standards. Here we develop a quantitative framework for modelling the growth of hESC colonies from a given seeding density based on stochastic exponential growth. This allows us to identify the timescales for colony merges and over which colony size no longer predicts the number of founding cells. We demonstrate the success of our model by applying it to our own experiments of hESC colony growth; while this is based on a particular experimental set-up, the model can be applied more generally to other cell lines and experimental conditions to predict these important timescales