96 research outputs found
The Necessity of Improving Reporting Quality With a view of reporting non-financial measures (An Analytical Study)
Abstract There is an increasing trend for businesses to produce information on social, environmental and sustainable aspects of their operations. Although guidelines exist for the production of such reporting, and legal requirements can be found in some countries, their use is often optional and the disclosure of non-financial information is mandatory only in limited cases. Companies may find it in their interest to disclose voluntarily certain non-financial information ,particularly if it is designed as part of a package to improve their credibility and acceptance in key markets, or if it enables them to undertake business more successfully. In sectors dominated by large multinational enterprises, disclosure of such information may be seen as an important business driver. This paper is an analytical study that examines whether the use of non-financial information is important in company reporting
Hypopituitarism is associated with lower oxytocin concentrations and reduced empathic ability
Purpose Central diabetes insipidus is characterised by arginine vasopressin deficiency. Oxytocin is structurally related to vasopressin and is synthesised in the same hypothalamic nuclei, thus we hypothesised that patients with acquired central diabetes insipidus and anterior hypopituitarism would display an oxytocin deficiency. Moreover, psychological research has demonstrated that oxytocin influences social and emotional behaviours, particularly empathic behaviour. We therefore further hypothesised that central diabetes insipidus patients would perform worse on empathy-related tasks, compared to age-matched and gender-matched clinical control (clinical control-isolated anterior hypopituitarism) and healthy control groups.
Method Fifty-six participants (age 46.54 ± 16.30 yrs; central diabetes insipidus: n = 20, 8 males; clinical control: n = 15, 6 males; healthy control: n = 20, 7 males) provided two saliva samples which were analysed for oxytocin and completed two empathy tasks.
Results Hypopituitary patients (both central diabetes insipidus and clinical control groups) had significantly lower oxytocin concentrations compared to healthy control participants. Hypopituitary patients also performed significantly worse on both the reading the mind in the eyes task and the facial expression recognition task compared to healthy control participants. Regression analyses further revealed that central diabetes insipidus patients’ oxytocin concentrations significantly predicted their performance on easy items of the reading the mind in the eyes task.
Conclusions Hypopituitarism may therefore be associated with reduced oxytocin concentrations and impaired empathic ability. While further studies are needed to replicate these findings, our data suggest that oxytocin replacement may offer a therapeutic approach to improve psychological well-being in patients with hypopituitarism
Heterozygous Mutation of Drosophila Opa1 Causes the Development of Multiple Organ Abnormalities in an Age-Dependent and Organ-Specific Manner
Optic Atrophy 1 (OPA1) is a ubiquitously expressed dynamin-like GTPase in the inner mitochondrial membrane. It plays important roles in mitochondrial fusion, apoptosis, reactive oxygen species (ROS) and ATP production. Mutations of OPA1 result in autosomal dominant optic atrophy (DOA). The molecular mechanisms by which link OPA1 mutations and DOA are not fully understood. Recently, we created a Drosophila model to study the pathogenesis of optic atrophy. Heterozygous mutation of Drosophila OPA1 (dOpa1) by P-element insertion results in no obvious morphological abnormalities, whereas homozygous mutation is embryonic lethal. In eye-specific somatic clones, homozygous mutation of dOpa1 causes rough (mispatterning) and glossy (decreased lens deposition) eye phenotypes in adult Drosophila. In humans, heterozygous mutations in OPA1 have been associated with mitochondrial dysfunction, which is predicted to affect multiple organs. In this study, we demonstrated that heterozygous dOpa1 mutation perturbs the visual function and an ERG profile of the Drosophila compound eye. We independently showed that antioxidants delayed the onset of mutant phenotypes in ERG and improved larval vision function in phototaxis assay. Furthermore, heterozygous dOpa1 mutation also caused decreased heart rate, increased heart arrhythmia, and poor tolerance to stress induced by electrical pacing. However, antioxidants had no effects on the dysfunctional heart of heterozygous dOpa1 mutants. Under stress, heterozygous dOpa1 mutations caused reduced escape response, suggesting abnormal function of the skeletal muscles. Our results suggest that heterozygous mutation of dOpa1 shows organ-specific pathogenesis and is associated with multiple organ abnormalities in an age-dependent and organ-specific manner
CD8+ T Cells as a Source of IFN-γ Production in Human Cutaneous Leishmaniasis
Cutaneous leishmaniasis (CL) is usually a self-healing skin lesion caused by different species of Leishmania parasite. Resistance and susceptibility of mice to Leishmania major infection is associated with two types of CD4+ T lymphocytes development: Th1 type response with production of cytokine IFN-γ is associated with resistance, whereas Th2 type response with production of cytokines IL-4 and IL-5 is associated with susceptibility. A clear Th1/Th2 dichotomy similar to murine model is not defined in human leishmaniasis and we need as much information as possible to define marker(s) of protection. We purified CD4+/CD8+ T cells, stimulated them with Leishmania antigens and analysed gene and protein expression of Th1/Th2 cytokines in volunteers with a history of self-healing CL who are presumed to be protected against further Leishmania infection. We have seen significant upregulation of IFN-γ gene expression and high IFN-γ production in the Leishmania stimulated CD4+ T cells and CD8+ T cells. We concluded that both antigen-specific IFN-γ producing CD4+ Th1 cells and IFN-γ producing CD8+ T cells contribute to the long term protection in individuals with a history of CL. This proves the importance of CD8+ T cells as a source of IFN-γ in Th1-like immune responses
Mitochondrial Changes in Ageing Caenorhabditis elegans – What Do We Learn from Superoxide Dismutase Knockouts?
One of the most popular damage accumulation theories of ageing is the mitochondrial free radical theory of ageing (mFRTA). The mFRTA proposes that ageing is due to the accumulation of unrepaired oxidative damage, in particular damage to mitochondrial DNA (mtDNA). Within the mFRTA, the “vicious cycle” theory further proposes that reactive oxygen species (ROS) promote mtDNA mutations, which then lead to a further increase in ROS production. Recently, data have been published on Caenorhabditis elegans mutants deficient in one or both forms of mitochondrial superoxide dismutase (SOD). Surprisingly, even double mutants, lacking both mitochondrial forms of SOD, show no reduction in lifespan. This has been interpreted as evidence against the mFRTA because it is assumed that these mutants suffer from significantly elevated oxidative damage to their mitochondria. Here, using a novel mtDNA damage assay in conjunction with related, well established damage and metabolic markers, we first investigate the age-dependent mitochondrial decline in a cohort of ageing wild-type nematodes, in particular testing the plausibility of the “vicious cycle” theory. We then apply the methods and insights gained from this investigation to a mutant strain for C. elegans that lacks both forms of mitochondrial SOD. While we show a clear age-dependent, linear increase in oxidative damage in WT nematodes, we find no evidence for autocatalytic damage amplification as proposed by the “vicious cycle” theory. Comparing the SOD mutants with wild-type animals, we further show that oxidative damage levels in the mtDNA of SOD mutants are not significantly different from those in wild-type animals, i.e. even the total loss of mitochondrial SOD did not significantly increase oxidative damage to mtDNA. Possible reasons for this unexpected result and some implications for the mFRTA are discussed
Does oxytocin lead to emotional interference during a working memory paradigm?
FSW - Self-regulation models for health behavior and psychopathology - ou
Drosophila pericardial nephrocyte ultrastructure changes during ageing
Here we show that a labyrinth channel compartment and slit diaphragms, which are the histological structures
enabling insect nephrocytes ultrafiltration, are established during embryogenesis first by the garland nephrocytes (GCNs). The later pericardial nephrocytes, which represent the majority of functional nephrocytes in larvae and adults, lack these characteristic features at the embryonic stage. During larval development, a subpopulation of the pericardial cells survives and matures into functional nephrocytes (PCNs) displaying a fully differentiated slit diaphragm and a labyrinth channel compartment. Likely the embryonic pericardial cells have primary functions other than ultrafiltration (e.g. in production and secretion of ECM constituents). We also show, for the first time, that PCNs in the adult fly undergo dramatic histological degeneration upon ageing. The slit diaphragms disappear, the labyrinth channel system degenerates and the lysosomal compartment becomes highly enriched with electron-dense material. When using nephrocytes as a model for genetic screening purposes or to investigate the specific role of genes involved in endocytosis, histological changes occurring upon ageing need to be taken into account when interpreting structural data
Analysis of multiple virtual private network tunnels over wireless LANs
In this paper, the analysis and experimental results for evaluation of the performance of multiple VPNs over an IEEE 802.11b wireless network are presented. A comprehensive set of measurements on the application throughput, packet loss, CPU utilization, and round trip delay for different traffic conditions are obtained and analyzed. The results and analysis of the investigations indicate that the packet generation rate, the payload data size, and the CPU processing power are critical factors affecting the performance of such tunnels
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