918 research outputs found
Relationship between online role-playing games, personality and interpersonal relationships
Online gaming is a relatively new concept, yet due to the millions of followers these games have attracted over the past decade; it is not difficult to deduce that they are not going away any time soon. Individuals use the Internet for many things, including news, email, shopping, instant messaging and entertainment (gaming) (Griffiths, et al., 2003; Yee, 2006a; 2006b). Millions of these same individuals play Massively Multiplayer Online Role-Playing Games (MMORPGs) as their source of entertainment. These players interact socially within the game with one another, many on a daily basis, and spend huge amounts of time doing so. During these long hours, research has shown that many of these players form relationships and some of these relationships lead to real life relationships (Cole & Griffiths, 2007; Yee, 2006b). Many of these individuals consider these online relationships equal to their offline relationships (Ng & Wiemer-Hastings, 2005). It is suggested that these players are introverted and lack social interaction; however, some believe that using the Internet in this manner is equivalent to offline face to face social interaction. Many lose track of the time while playing MMORPGs and when engaging in other online activities, and some of these individuals experience symptoms related to loneliness (Ng & Wiemer-Hastings, 2005). Therefore, previous research suggests there is a relationship between Online Gaming, Personality, and Interpersonal Relationships. This study was designed to examine relationships between personality characteristics and amount of time playing a popular game called World of Warcraft (WoW). Additionally, this study examined how motivations to play the game are related to personality characteristics, preference for online interpersonal interaction, and social anxiety.
A Demographics Questionnaire including age, country of residence, sex, occupation, employment status and other information about their online game playing was used. Additionally, the M5-50 Personality Inventory (McCord, 2002) was used as a short measure of the participant’s personality traits, collected through a fifty item scale which resulted in scores for the five domains of: Neuroticism, Extraversion, Openness to Experience, Conscientiousness, and Agreeableness. The participants also completed the Preference for Online Social Interaction Questionnaire (Caplan, 2003) which is a 4 item measure of the individual’s preference for online vs. offline face to face social interaction. The items were summed for a total score with higher scores representing preference for online social interaction. Motivations for Play Questionnaire (Yee, 2006a), which measures activities the participant engages in while online, which MMORPGs they play, the amount of time spent playing the specified MMORPG per week, and activities they are involved in while playing the MMORPG. The scale consisted of 40 questions which participants answered using a five point response scale then the individual items were summed into each of the primary components. Finally, the Interaction Anxiousness Scale (IAS), a measure of social anxiety was completed by the participants. The scale consisted of 15 items which participants answered based on a five point Likert-type scale. Scores were summed and overall higher scores on the scale reflect higher levels of social anxiety.
The study included 381 participants who were recruited from the Internet sites where WoW players frequently post and read messages. The participants were 88% male and 12% female and the range of participants’ ages was 18 to 69 years, with a mean of 24.29 years. Participants were actually engaged in playing the MMORPG “World of Warcraft”. The median amount of time spent playing WoW per week was 16 to 20 hours.
A small, positive correlation was found between the amount of time spent playing WoW and Neuroticism and a small, negative correlation between of time spent playing WoW and Extraversion. Examination of the relationships between achievement motivation to play and Openness to Experience and Conscientiousness found small, negative correlations between achievement motivation to play and Openness to Experience and Conscientiousness with higher levels of motivation to play associated with lower levels of Openness to Experience and Conscientiousness. An examination of the relationship between social motivation to play, Extraversion, Agreeableness and Openness to Experience found small, positive relationships between social motivation to play and Extraversion, Agreeableness, and Openness to Experience. The relationship between immersion motivation to play and Extraversion, Conscientiousness, and Openness to Experience was investigated which found small, negative relationships between immersion motivation to play and Extraversion and Conscientiousness; and a small, positive relationship between immersion motivation to play and Openness to Experience. Finally, the relationship between the preference for online social interaction and the interactive anxiousness scale was investigated resulting in a moderate to strong, positive relationship, with higher levels of preference for online social interaction associated with higher levels of interactive anxiousness
Laser-wakefield accelerators as hard x-ray sources for 3D medical imaging of human bone
A bright μm-sized source of hard synchrotron x-rays (critical energy Ecrit > 30 keV) based on the betatron oscillations of laser wakefield accelerated electrons has been developed. The potential of this source for medical imaging was demonstrated by performing micro-computed tomography of a human femoral trabecular bone sample, allowing full 3D reconstruction to a resolution below 50 μm. The use of a 1 cm long wakefield accelerator means that the length of the beamline (excluding the laser) is dominated by the x-ray imaging distances rather than the electron acceleration distances. The source possesses high peak brightness, which allows each image to be recorded with a single exposure and reduces the time required for a full tomographic scan. These properties make this an interesting laboratory source for many tomographic imaging applications
Cholesteryl hemiazelate causes lysosome dysfunction impacting vascular smooth muscle cell homeostasis
In atherosclerotic lesions, vascular smooth muscle cells (VSMCs) represent half of the foam cell population, which is characterized by an aberrant accumulation of undigested lipids within lysosomes. Loss of lysosome function impacts VSMC homeostasis and disease progression. Understanding the molecular mechanisms underlying lysosome dysfunction in these cells is, therefore, crucial. We identify cholesteryl hemiazelate (ChA), a stable oxidation end-product of cholesteryl-polyunsaturated fatty acid esters, as an inducer of lysosome malfunction in VSMCs. ChA-treated VSMCs acquire a foam-cell-like phenotype, characterized by enlarged lysosomes full of ChA and neutral lipids. The lysosomes are perinuclear and exhibit degradative capacity and cargo exit defects. Lysosome luminal pH is also altered. Even though the transcriptional response machinery and autophagy are not activated by ChA, the addition of recombinant lysosomal acid lipase (LAL) is able to rescue lysosome dysfunction. ChA significantly affects VSMC proliferation and migration, impacting atherosclerosis. In summary, this work shows that ChA is sufficient to induce lysosomal dysfunction in VSMCs, that, in ChA-treated VSMCs, neither lysosome biogenesis nor autophagy are triggered, and, finally, that recombinant LAL can be a therapeutic approach for lysosomal dysfunction
Using zeta-potential measurements to quantify peptide partition to lipid membranes
© The Author(s) 2011. This article is published with open access at Springerlink.com.Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.Many cellular phenomena occur on the biomembranes. There are plenty of molecules (natural or xenobiotics) that interact directly or partially with the cell membrane. Biomolecules, such as several peptides (e.g., antimicrobial peptides) and proteins, exert their effects at the cell membrane level. This feature makes necessary investigating their interactions with lipids to clarify their mechanisms of action and side effects necessary. The determination of molecular lipid/water partition constants (Kp) is frequently used to quantify the extension of the interaction. The determination of this parameter has been achieved by using different methodologies, such as UV-Vis absorption spectrophotometry, fluorescence spectroscopy and ζ-potential measurements. In this work, we derived and tested a mathematical model to determine the Kp from ζ-potential data. The values obtained with this method were compared with those obtained by fluorescence spectroscopy, which is a regular technique used to quantify the interaction of intrinsically fluorescent peptides with selected biomembrane model systems. Two antimicrobial peptides (BP100 and pepR) were evaluated by this new method. The results obtained by this new methodology show that ζ-potential is a powerful technique to quantify peptide/lipid interactions of a wide variety of charged molecules, overcoming some of the limitations inherent to other techniques, such as the need for fluorescent labeling.This work was partially supported by project PTDC/QUI/ 69937/2006 from Fundação para a Ciência e Tecnologia-Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES, Portugal), and by Fundação Calouste Gulbenkian (Portugal). JMF and MMD also thank FCT-MCTES for grants IMM/BT/37-2010 and SFRH/BD/41750/2007, respectively
Detection and Antimicrobial Resistance Profile of Enteropathogenic (EPEC) and Shigatoxigenic Escherichia coli (STEC) in Conventional and Organic Broiler Chickens
ABSTRACT Enteropatogenic Escherichia coli (EPEC) and shigatoxigenic E. coli (STEC), are generally poultry and poultry product isolate and can cause serious human infections. Many strains may become resistant to various antimicrobials, which can hinder the treatment of bacterial diseases. Organic farming seeks to avoid the selection and frequency of antimicrobial-resistant bacteria. This study aims to verify the resistance of EPEC and STEC from organic and conventional (industrial) broiler isolates to antimicrobials. All isolates were submitted to disk diffusion test with tetracycline, gentamicin, enrofloxacin, ceftriaxone and amoxicillin + clavulanate (TET, GEN, ENO, CTX, AMC) and PCR to detect specific virulence genes for EPEC and STEC. A total of 297 E. coli strains were isolated, 213 from conventional. In organic broiler, 84 strains were isolated. The strains from the conventional broiler isolates were resistant to five antimicrobials tested: TET 48.82% (104/213), ENO 28.17% (60/213), CTX 15.49% (33/213), GEN 14.55% (31/213), and AMC 7.04% (15/213), and 9.86% (21/213) were considered multidrug-resistant. Organic chicken strains were resistant to four of the antimicrobials tested: TET 35.7% (30/84), ENO 9.5% (8/84), CTX 2.4% (2/84), GEN 4.8% (4/84). Of the strains from the organic broiler chicken isolates, only 1.2% (1/84) was considered multidrug-resistant. No EPEC and STEC were found in the organic chicken samples. The multidrug resistance was characterized in 9.52% (2/21) of the EPEC and 4.76% (1/21) of the STEC. The study demonstrated the absence of EPEC and STEC strains in organic broilers and carcasses and a lower frequency of multiresistant strains compared to conventional breeding
Bright X-ray radiation from plasma bubbles in an evolving laser wakefield accelerator
We show that the properties of the electron beam and bright X-rays produced by a laser wakefield accelerator can be predicted if the distance over which the laser self-focuses and compresses prior to self-injection is taken into account. A model based on oscillations of the beam inside a plasma bubble shows that performance is optimised when the plasma length is matched to the laser depletion length. With a 200~TW laser pulse this results in an X-ray beam with median photon energy of 20 keV, photons per shot and a peak brightness of photons s mrad mm (0.1 % BW)
Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines
A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us
IKZF1 Deletions with COBL Breakpoints Are Not Driven by RAG-Mediated Recombination Events in Acute Lymphoblastic Leukemia
IKZF1 deletion (ΔIKZF1) is an important predictor of relapse in both childhood and adult B-cell precursor acute lymphoblastic leukemia (B-ALL). Previously, we revealed that COBL is a hotspot for breakpoints in leukemia and could promote IKZF1 deletions. Through an international collaboration, we provide a detailed genetic and clinical picture of B-ALL with COBL rearrangements (COBL-r). Patients with B-ALL and IKZF1 deletion (n = 133) were included. IKZF1 ∆1-8 were associated with large alterations within chromosome 7: monosomy 7 (18%), isochromosome 7q (10%), 7p loss (19%), and interstitial deletions (53%). The latter included COBL-r, which were found in 12% of the IKZF1 ∆1-8 cohort. Patients with COBL-r are mostly classified as intermediate cytogenetic risk and frequently harbor ETV6, PAX5, CDKN2A/B deletions. Overall, 56% of breakpoints were located within COBL intron 5. Cryptic recombination signal sequence motifs were broadly distributed within the sequence of COBL, and no enrichment for the breakpoint cluster region was found. In summary, a diverse spectrum of alterations characterizes ΔIKZF1 and they also include deletion breakpoints within COBL. We confirmed that COBL is a hotspot associated with ΔIKZF1, but these rearrangements are not driven by RAG-mediated recombination
- …