364 research outputs found
Violent video games and morality: a meta-ethical approach
This paper considers what it is about violent video games that leads one reasonably minded person to declare "That is immoral" while another denies it. Three interpretations of video game content a re discussed: reductionist, narrow, and broad. It is argued that a broad interpretation is required for a moral objection to be justified. It is further argued that understanding the meaning of moral utterances – like "x is immoral" – is important to an understanding of why there is a lack of moral consensus when it comes to the content of violent video games. Constructive ecumenical expressivism is presented as a means of explaining what it is that we are doing when we make moral pronouncements and why, when it comes to video game content, differing moral attitudes abound. Constructive ecumenical expressivism is also presented as a means of illuminating what would be required for moral consensus to be achieved
A Condensation-Ordering Mechanism in Nanoparticle-Catalyzed Peptide Aggregation
Nanoparticles introduced in living cells are capable of strongly promoting
the aggregation of peptides and proteins. We use here molecular dynamics
simulations to characterise in detail the process by which nanoparticle
surfaces catalyse the self- assembly of peptides into fibrillar structures. The
simulation of a system of hundreds of peptides over the millisecond timescale
enables us to show that the mechanism of aggregation involves a first phase in
which small structurally disordered oligomers assemble onto the nanoparticle
and a second phase in which they evolve into highly ordered beta-sheets as
their size increases
Fortified breakfast cereal consumed daily for 12 wk leads to a significant improvement in micronutrient intake and micronutrient status in adolescent girls: a randomised controlled trial
Background: Poor micronutrient status is reported among adolescents across Europe and USA. This may be related to the well-documented decline in the regular consumption of breakfast by this group. The regular consumption of a breakfast cereal offers a possible means to improve micronutrient status; fortified cereal is likely to have enhanced benefit. A study was conducted to determine the efficacy of the regular consumption of a fortified cereal with milk, compared with unfortified cereal, consumed either as a breakfast or a supper, in improving micronutrient intake and micronutrient status of adolescent girls.
Methods: A randomised, double-blind, placebo-controlled intervention trial was conducted in girls recruited at ages 16–19 years, from schools and colleges in Sheffield, UK. Girls were randomised to receive 50 g fortified or unfortified cereal, with 150 ml semi-skimmed milk, daily, for 12 weeks, as a breakfast or as a supper. Dietary intake was estimated using a 4-d food diary and blood collected for the assessment of nutritional status. Within-group changes were tested using a paired sample t test; two-way ANOVA was used to analyse effects of the intervention, with cereal type and time of consumption as factors, correcting for baseline values. The analysis was conducted on 71 girls who completed the study.
Results: Consumption of unfortified cereal elicited an increase in the intake of vitamins B1, B2 and B6; consumption of fortified cereal elicited increases in vitamins B1, B2, B6, B12, folate and iron (P < 0.001) and of vitamin D (P = 0.007), all increases were significantly greater than for unfortified cereal. Consumption of the fortified cereal also led to a significant improvement in biomarkers of status for vitamins B2, B12, folate and of iron, compared with girls receiving the unfortified cereal, and maintained vitamin D status, in contrast with the girls receiving the unfortified cereal (P < 0.001).
Conclusions: The daily consumption of cereal with milk for 12 weeks by adolescent girls, increased intakes of micronutrients. The consumption of fortified cereal elicited greater increases than for unfortified cereal and improved biomarkers of micronutrient status. The findings justify strategies to encourage the consumption of fortified cereal with milk by adolescents, either as a breakfast or a supper
Rare causes of scoliosis and spine deformity: experience and particular features
<p>Abstract</p> <p>Background</p> <p>Spine deformity can be idiopathic (more than 80% of cases), neuromuscular, congenital or neurofibromatosis-related. However, there are many disorders that may also be involved. We present our experience treating patients with scoliosis or other spine deformities related to rare clinical entities.</p> <p>Methods</p> <p>A retrospective study of the records of a school-screening study in North-West Greece was performed, covering a 10-year period (1992–2002). The records were searched for patients with deformities related to rare disorders. These patients were reviewed as regards to characteristics of underlying disorder and spine deformity, treatment and results, complications, intraoperative and anaesthesiologic difficulties particular to each case.</p> <p>Results</p> <p>In 13 cases, the spine deformity presented in relation to rare disorders. The underlying disorder was rare neurological disease in 2 cases (Rett syndrome, progressive hemidystonia), muscular disorders (facioscapulohumeral muscular dystrophy, arthrogryposis) in 2 patients, osteogenesis imperfecta in 2 cases, Marfan syndrome, osteopetrosis tarda, spondyloepiphyseal dysplasia congenita, cleidocranial dysplasia and Noonan syndrome in 1 case each. In 2 cases scoliosis was related to other congenital anomalies (phocomelia, blindness). Nine of these patients were surgically treated. Surgery was avoided in 3 patients.</p> <p>Conclusion</p> <p>This study illustrates the fact that different disorders are related with curves with different characteristics, different accompanying problems and possible complications. Investigation and understanding of the underlying pathology is an essential part of the clinical evaluation and preoperative work-up, as clinical experience at any specific center is limited.</p
Impaired immune responses in the lungs of aged mice following influenza infection
<p>Abstract</p> <p>Background</p> <p>Each year, influenza virus infection causes severe morbidity and mortality, particularly in the most susceptible groups including children, the elderly (>65 years-old) and people with chronic respiratory diseases. Among the several factors that contribute to the increased susceptibility in elderly populations are the higher prevalence of chronic diseases (<it>e.g</it>. diabetes) and the senescence of the immune system.</p> <p>Methods</p> <p>In this study, aged and adult mice were infected with sublethal doses of influenza virus (A/Puerto Rico/8/1934). Differences in weight loss, morbidity, virus titer and the kinetics of lung infiltration with cells of the innate and adaptive immune responses were analyzed. Additionally, the main cytokines and chemokines produced by these cells were also assayed.</p> <p>Results</p> <p>Compared to adult mice, aged mice had higher morbidity, lost weight more rapidly, and recovered more slowly from infection. There was a delay in the accumulation of granulocytic cells and conventional dendritic cells (cDCs), but not macrophages in the lungs of aged mice compared to adult animals. The delayed infiltration kinetics of APCs in aged animals correlated with alteration in their activation (CD40 expression), which also correlated with a delayed detection of cytokines and chemokines in lung homogenates. This was associated with retarded lung infiltration by natural killer (NK), CD4<sup>+ </sup>and CD8<sup>+ </sup>T-cells. Furthermore, the percentage of activated (CD69+) influenza-specific and IL-2 producer CD8+ T-cells was higher in adult mice compared to aged ones. Additionally, activation (CD69+) of adult B-cells was earlier and correlated with a quicker development of neutralizing antibodies in adult animals.</p> <p>Conclusion</p> <p>Overall, alterations in APC priming and activation lead to delayed production of cytokines and chemokines in the lungs that ultimately affected the infiltration of immune cells following influenza infection. This resulted in delayed activation of the adaptive immune response and subsequent delay in clearance of virus and prolonged illness in aged animals. Since the elderly are the fastest growing segment of the population in developed countries, a better understanding of the changes that occur in the immune system during the aging process is a priority for the development of new vaccines and adjuvants to improve the immune responses in this population.</p
A DNA Vaccine against Chikungunya Virus Is Protective in Mice and Induces Neutralizing Antibodies in Mice and Nonhuman Primates
Chikungunya virus (CHIKV) is an emerging mosquito-borne alphavirus indigenous to tropical Africa and Asia. Acute illness is characterized by fever, arthralgias, conjunctivitis, rash, and sometimes arthritis. Relatively little is known about the antigenic targets for immunity, and no licensed vaccines or therapeutics are currently available for the pathogen. While the Aedes aegypti mosquito is its primary vector, recent evidence suggests that other carriers can transmit CHIKV thus raising concerns about its spread outside of natural endemic areas to new countries including the U.S. and Europe. Considering the potential for pandemic spread, understanding the development of immunity is paramount to the development of effective counter measures against CHIKV. In this study, we isolated a new CHIKV virus from an acutely infected human patient and developed a defined viral challenge stock in mice that allowed us to study viral pathogenesis and develop a viral neutralization assay. We then constructed a synthetic DNA vaccine delivered by in vivo electroporation (EP) that expresses a component of the CHIKV envelope glycoprotein and used this model to evaluate its efficacy. Vaccination induced robust antigen-specific cellular and humoral immune responses, which individually were capable of providing protection against CHIKV challenge in mice. Furthermore, vaccine studies in rhesus macaques demonstrated induction of nAb responses, which mimicked those induced in convalescent human patient sera. These data suggest a protective role for nAb against CHIKV disease and support further study of envelope-based CHIKV DNA vaccines
Translation Levels Control Multi-Spanning Membrane Protein Expression
Attempts to express eukaryotic multi-spanning membrane proteins at high-levels have been generally unsuccessful. In order to investigate the cause of this limitation and gain insight into the rate limiting processes involved, we have analyzed the effect of translation levels on the expression of several human membrane proteins in Escherichia coli (E. coli). These results demonstrate that excessive translation initiation rates of membrane proteins cause a block in protein synthesis and ultimately prevent the high-level accumulation of these proteins. Moderate translation rates allow coupling of peptide synthesis and membrane targeting, resulting in a significant increase in protein expression and accumulation over time. The current study evaluates four membrane proteins, CD20 (4-transmembrane (TM) helixes), the G-protein coupled receptors (GPCRs, 7-TMs) RA1c and EG-VEGFR1, and Patched 1 (12-TMs), and demonstrates the critical role of translation initiation rates in the targeting, insertion and folding of integral membrane proteins in the E. coli membrane
Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties
Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl2) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure
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